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Office of Scientific and Technical Information
Cathodic Arc Plasma Deposition
Office of Scientific and Technical Information (OSTI)
Cathodic Arc Plasma Deposition Cathodic Arc Plasma Deposition André Anders Lawrence Berkeley National Laboratory, University of California, 1 Cyclotron Road, Mailstop 53, Berkeley, California 94720 email@example.com Abstract Cathodic arc plasma deposition is one of oldest coatings technologies. Over the last two decades it has become the technology of choice for hard, wear resistant coatings on cutting and forming tools, corrosion resistant and decorative coatings on door knobs, shower heads, jewelry, and many other substrates. The history, basic physics of cathodic arc operation, the infamous macroparticle problem and common filter solutions are reviewed. Cathodic arc plasmas stand out due to their high degree of ionization, with important consequences for film nucleation, growth, and efficient utilization of substrate bias. The
Contamination due to memory effects in filtered vacuum arc plasma deposition systems
SciTech Connect
Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.
Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.
Solid oxide fuel cell processing using plasma arc spray deposition techniques. Final report
DOE Green Energy (OSTI)
The Westinghouse Electric Corporation, in conjunction with the Thermal Spray Laboratory of the State University of New York, Stony Brook, investigated the fabrication of a gas-tight interconnect layer on a tubular solid oxide fuel cell with plasma arc spray deposition. The principal objective was to determine the process variables for the plasma spray deposition of an interconnect with adequate electrical conductivity and other desired properties. Plasma arc spray deposition is a process where the coating material in powder form is heated to or above its melting temperature, while being accelerated by a carrier gas stream through a high power electric arc. The molten powder particles are directed at the substrate, and on impact, form a coating consisting of many layers of overlapping, thin, lenticular particles or splats. The variables investigated were gun power, spray distance, powder feed rate, plasma gas flow rates, number of gun passes, powder size distribution, injection angle of powder into the plasma plume, vacuum or atmospheric plasma spraying, and substrate heating. Typically, coatings produced by both systems showed bands of lanthanum rich material and cracking with the coating. Preheating the substrate reduced but did not eliminate internal coating cracking. A uniformly thick, dense, adherent interconnect of the desired chemistry was finally achieved with sufficient gas- tightness to allow fabrication of cells and samples for measurement of physical and electrical properties. A cell was tested successfully at 1000{degree}C for over 1,000 hours demonstrating the mechanical, electrical, and chemical stability of a plasma-arc sprayed interconnect layer.
Ray, E.R.; Spengler, C.J.; Herman, H.
Solid oxide fuel cell processing using plasma arc spray deposition techniques
Graphene layer growth on silicon substrates with nickel film by pulse arc plasma deposition
Science Conference Proceedings (OSTI)
Carbon layer has been grown on a Ni/SiO{sub 2}/Si(111) substrate under high vacuum pressure by pulse arc plasma deposition. From the results of Raman spectroscopy for the sample, it is found that graphene was formed by ex-situ annealing of sample grown at room temperature. Furthermore, for the sample grown at high temperature, graphene formation was shown and optimum temperature was around 1000 Degree-Sign C. Transmission electron microscopy observation of the sample suggests that the graphene was grown from step site caused by grain of Ni film. The results show that the pulse arc plasma technique has the possibility for acquiring homogenous graphene layer with controlled layer thickness.
Fujita, K.; Banno, K.; Aryal, H. R.; Egawa, T. [Research Center for Nano-Device and System, Nagoya Institute of Technology, Gokiso-cho, Showa-Ku, Nagoya 466-8555 (Japan)
Filters for cathodic arc plasmas
DOE Patents (OSTI)
Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.
Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA); Bilek, Marcela M. M. (Engadine, AU); Brown, Ian G. (Berkeley, CA)
Miniaturized cathodic arc plasma source
A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.
Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA)
Electrical properties of a-C:Mo films produced by dual-cathode filtered cathodic arc plasma deposition
Molybdenum-containing amorphous carbon (a-C:Mo) thin films were prepared using a dual-cathode filtered cathodic arc plasma source with a molybdenum and a carbon (graphite) cathode. The Mo content in the films was controlled by varying the deposition pulse ratio of Mo and C. Film sheet resistance was measured in situ at process temperature, which was close to room temperature, as well as ex situ as a function of temperature (300-515 K) in ambient air. Film resistivity and electrical activation energy were derived for different Mo and C ratios and substrate bias. Film thickness was in the range 8-28 nm. Film resistivity varied from 3.55x10-4 Omega m to 2.27x10-6 Omega m when the Mo/C pulse ratio was increased from 0.05 to 0.4, with no substrate bias applied. With carbon-selective bias, the film resistivity was in the range of 4.59x10-2 and 4.05 Omega m at a Mo/C pulse ratio of 0.05. The electrical activation energy decreased from 3.80x10-2 to 3.36x10-4 eV when the Mo/C pulse ratio was increased in the absence of bias, and from 0.19 to 0.14 eV for carbon-selective bias conditions. The resistivity of the film shifts systematically with the amounts of Mo and upon application of substrate bias voltage. The intensity ratio of the Raman D-peak and G-peak (ID/IG) correlated with the pre-exponential factor (sigma 0) which included charge carrier density and density of states.
Sansongsiri, Sakon; Anders, Andre; Yodsombat, Banchob
Purification of tantalum by plasma arc melting
Purification of tantalum by plasma arc melting. The level of oxygen and carbon impurities in tantalum was reduced by plasma arc melting the tantalum using a flowing plasma gas generated from a gas mixture of helium and hydrogen. The flowing plasma gases of the present invention were found to be superior to other known flowing plasma gases used for this purpose.
Dunn, Paul S. (Santa Fe, NM); Korzekwa, Deniece R. (Los Alamos, NM)
Apparatus for gas-metal arc deposition
Apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites. The apparatus contains an arc chamber for confining a D.C. electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment with the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspenion of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite.
Buhrmaster, Carol L. (Corning, NY); Clark, Denis E. (Idaho Falls, ID); Smartt, Herschel B. (Idaho Falls, ID)
Method for gas-metal arc deposition
Method and apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites. The apparatus contains an arc chamber for confining a D.C. electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment wiht the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspension of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite.
Method and apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites are disclosed. The apparatus contains an arc chamber for confining a D.C. electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment with the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspension of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite. 1 fig.
Buhrmaster, C.L.; Clark, D.E.; Smartt, H.B.
A filtered cathodic arc deposition apparatus and method
A filtered cathodic arc deposition method and apparatus are described for the production of highly dense, wear resistant coatings which are free from macro particles. The filtered cathodic arc deposition apparatus includes a cross shaped vacuum chamber which houses a cathode target having an evaporable surface comprised of the coating material, means for generating a stream of plasma, means for generating a transverse magnetic field, and a macro particle deflector. The transverse magnetic field bends the generated stream of plasma in the direction of a substrate. Macro particles are effectively filtered from the stream of plasma by traveling, unaffected by the transverse magnetic field, along the initial path of the plasma stream to a macro particle deflector. The macro particle deflector has a preformed surface which deflects macro particles away from the substrate.
Krauss, Alan R.
Plasma arc torch with coaxial wire feed
A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.
Hooper, Frederick M (Albuquerque, NM)
Properties of vacuum arc deposited amorphous hard carbon films
Amorphous hard carbon films formed by vacuum arc deposition are hydrogen-free, dense, and very hard. The properties of amorphous hard carbon films depend strongly on the energy of the incident ions. A technique which is called Plasma Immersion Ion Implantation can be applied to vacuum arc deposition of amorphous hard carbon films to influence the ion energy. The authors have studied the influence of the ion energy on the elastic modulus determined by an ultrasonic method, and have measured the optical gap for films with the highest sp{sup 3} content they have obtained so far with this deposition technique. The results show an elastic modulus close to that of diamond, and an optical gap of 2.1 eV which is much greater than for amorphous hard carbon films deposited by other techniques.
Anders, S.; Anders, A.; Raoux, S. [Lawrence Berkeley Lab., CA (United States)] [and others
Surface plasma-arc cutting of stainless steel
This danger does not exist when plasma-arc cutting is used. Plasma-arc cutting also increases productivity and produces better quality gouged surfaces [2].
Formation of metal oxides by cathodic arc deposition
Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, an established, industrially applied technique for formation of nitrides (e.g. TiN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with desired cathode material is operated in an oxygen atmosphere, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on ALS components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}/Y{sub 2}O{sub 3}/AI{sub 2}O{sub 3}/Si as possible basic structures for passive optoelectronic integrated circuits, and Al{sub 2-x}Er{sub x}O{sub 3} thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 {mu}m. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells.
Anders, S.; Anders, A.; Rubin, M.; Wang, Z.; Raoux, S.; Kong, F.; Brown, I.G.
Method and apparatus for gas-metal arc deposition
Method and apparatus for gas-metal arc deposition of metal, metal alloys, and metal matrix composites are presented. The apparatus contains an arc chamber for confining a DC electrical arc discharge, the arc chamber containing an outlet orifice in fluid communication with a deposition chamber having a deposition opening in alignment with the orifice for depositing metal droplets on a coatable substrate. Metal wire is passed continuously into the arc chamber in alignment with the orifice. Electric arcing between the metal wire anode and the orifice cathode produces droplets of molten metal from the wire which pass through the orifice and into the deposition chamber for coating a substrate exposed at the deposition opening. When producing metal matrix composites, a suspension of particulates in an inert gas enters the deposition chamber via a plurality of feed openings below and around the orifice so that reinforcing particulates join the metal droplets to produce a uniform mixture which then coats the exposed substrate with a uniform metal matrix composite. 1 fig., 2 tabs.
Modeling of thermal plasma arc technology FY 1994 report
The thermal plasma arc process is under consideration to thermally treat hazardous and radioactive waste. A computer model for the thermal plasma arc technology was designed as a tool to aid in the development and use of the plasma arc-Joule beating process. The value of this computer model is to: (a) aid in understanding the plasma arc-Joule beating process as applied to buried waste or exhumed buried waste, (b) help design melter geometry and electrode configuration, (c) calculate the process capability of vitrifying waste (i.e., tons/hour), (d) develop efficient plasma and melter operating conditions to optimize the process and/or reduce safety hazards, (e) calculate chemical reactions during treatment of waste to track chemical composition of off-gas products, and composition of final vitrified waste form and (f) help compare the designs of different plasma-arc facilities. A steady-state model of a two-dimensional axisymmetric transferred plasma arc has been developed and validated. A parametric analysis was performed that studied the effects of arc length, plasma gas composition, and input power on the temperatures and velocity profiles of the slag and plasma gas. A two-dimensional transient thermo-fluid model of the US Bureau of Mines plasma arc melter has been developed. This model includes the growth of a slag pool. The thermo-fluid model is used to predict the temperature and pressure fields within a plasma arc furnace. An analysis was performed to determine the effects of a molten metal pool on the temperature, velocity, and voltage fields within the slag. A robust and accurate model for the chemical equilibrium calculations has been selected to determine chemical composition of final waste form and off-gas based on the temperatures and pressures within the plasma-arc furnace. A chemical database has been selected. The database is based on the materials to be processed in the plasma arc furnaces.
Hawkes, G.L.; Nguyen, H.D.; Paik, S.; McKellar, M.G.
Ohmic contacts for solar cells by arc plasma spraying
The method of applying ohmic contacts to a semiconductor, such as a silicon body or wafer used in solar cells, by the use of arc plasma spraying, and solar cells resulting therefrom.
Narasimhan, Mandayam C. (Seekonk, MA); Roessler, Barton (Barrington, RI); Loferski, Joseph J. (Providence, RI)
Physics of arcing, and implications to sputter deposition
E-Print Network (OSTI)
Series II. Mathematics, Physics and Chemistry vol. 88, I.Physics of arcing, and implications to sputter depositionleading to arcs and the physics of the arcing events
Anders, Andre
Filtered cathodic arc deposition with ion-species-selectivebias
A dual-cathode arc plasma source was combined with acomputer-controlled bias amplifier such as to synchronize substrate biaswith the pulsed production of plasma. In this way, bias can be applied ina material-selective way. The principle has been applied to the synthesismetal-doped diamond-like carbon films, where the bias was applied andadjusted when the carbon plasma was condensing, and the substrate was atground when the metal was incorporated. In doing so, excessive sputteringby too-energetic metal ions can be avoided while the sp3/sp2 ratio can beadjusted. It is shown that the resistivity of the film can be tuned bythis species-selective bias. The principle can be extended tomultiple-material plasma sources and complex materials
Anders, Andre; Pasaja, Nitisak; Sansongsiri, Sakon; Lim, SunnieH.N.
Pulse thermal processing of functional materials using directed plasma arc
A method of thermally processing a material includes exposing the material to at least one pulse of infrared light emitted from a directed plasma arc to thermally process the material, the pulse having a duration of no more than 10 s.
Ott, Ronald D. (Knoxville, TN); Blue, Craig A. (Knoxville, TN); Dudney, Nancy J. (Knoxville, TN); Harper, David C. (Kingston, TN)
Shielding of mirror FERF plasma by arc discharges
The feasibility of shielding a mirror-confined fusion plasma against erosion by incident neutrals with a plasma blanket generated by an array of hollow-cathode arc discharges was studied. Such a plasma blanket could also be used for linetying stabilization of a single mirror confined plasma as well as to provide a warm plasma stream for stabilization of microinstabilities. The requirements for the plasma blanket are dependent on the parameter ..gamma.., the ratio of the actual cross-field diffusion coefficient to the classical value. The power requirement compares favorably with power loss due to change exchange without shielding. More importantly, the blanket permits a relaxation of vacuum requirements to prevent erosion of the hot plasma by background neutrals.
Woo, J.T.
Plasma Arc Technology Dedicated to Solving Military Waste Problems
A thermal plasma is an electrically conductive gas capable of generating temperatures up to 10,000°C near its column. The energy generated by plasma arcs has recently been applied to hazardous waste disposal. Since 1989 the US Army Corps of Engineers Construction Engineering Research Laboratories have been active participants in research and development toward establishing plasma arc technology (PAT) as an efficient, economical and safe hazardous waste immobilization tool. In the U.S. the removal and disposal of asbestos contaminated material (ACM) generate significant amounts of hazardous waste. Recently, PAT has been used to convert ACM safely and efficiently into an innocuous ceramic substance no longer requiring Class I disposal. In addition to ACM waste disposal, PAT meets the waste disposal needs of pyrotechnic smoke assemblies, thermal batteries, proximity fuses, and contaminated soil. This paper will provide an overview of PAT and discuss Army and Department of Defense hazardous waste disposal needs.
Smith, E. D.; Zaghloul, H. H.
Plasma and Ion Assistance in Physical Vapor Deposition: AHistorical Perspective
Deposition of films using plasma or plasma-assist can betraced back surprisingly far, namely to the 18th century for arcs and tothe 19th century for sputtering. However, only since the 1960s thecoatings community considered other processes than evaporation for largescale commercial use. Ion Plating was perhaps the first importantprocess, introducing vapor ionization and substrate bias to generate abeam of ions arriving on the surface of the growing film. Ratherindependently, cathodic arc deposition was established as an energeticcondensation process, first in the former Soviet Union in the 1970s, andin the 1980s in the Western Hemisphere. About a dozen various ion-basedcoating technologies evolved in the last decades, all characterized byspecific plasma or ion generation processes. Gridded and gridless ionsources were taken from space propulsion and applied to thin filmdeposition. Modeling and simulation have helped to make plasma and ionseffects to be reasonably well understood. Yet--due to the complex, oftennon-linear and non-equilibrium nature of plasma and surfaceinteractions--there is still a place for the experience plasma"sourcerer."
Optical emission spectroscopy of metal vapor dominated laser-arc hybrid welding plasma
During laser-arc hybrid welding, plasma properties affect the welding process and the weld quality. However, hybrid welding plasmas have not been systematically studied. Here we examine electron temperatures, species densities, and electrical conductivity for laser, arc, and laser-arc hybrid welding using optical emission spectroscopy. The effects of arc currents and heat source separation distances were examined because these parameters significantly affect weld quality. Time-average plasma electron temperatures, electron and ion densities, electrical conductivity, and arc stability decrease with increasing heat source separation distance during hybrid welding. Heat source separation distance affects these properties more significantly than the arc current within the range of currents considered. Improved arc stability and higher electrical conductivity of the hybrid welding plasma result from increased heat flux, electron temperatures, electron density, and metal vapor concentrations relative to arc or laser welding.
Ribic, B.; DebRoy, T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Burgardt, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Mo-containing tetrahedral amorphous carbon deposited by dualfiltered cathodic vacuum arc with selective pulsed bias voltage
Metal-containing tetrahedral amorphous carbon films were produced by dual filtered cathodic vacuum arc (FCVA) plasma sources operated in sequential pulsed mode. A negatively pulsed bias was applied to the substrate only when carbon plasma was generated. Films thickness was measured after deposition by profilometry. Glass slides with silver pads were used as substrate for the of the measurement sheet resistance. The microstructure and composition of the films were characterized by Raman spectroscopy and Rutherford backscattering, respectively. It found that the electrical resistivity decreases with an increase of the Mo content, which can be ascribed to an increase of sp2 content and an increase of the sp2 cluster size.
Pasaja, Nitisak; Sansongsiri, Sakon; Anders, Andre; Vilaithong,Thiraphat; Intasiri, Sawate
Pulse Thermal Processing of Functional Materials Using a Directed Plasma Arc
Using pulses of high density infrared light from a directed plasma arc, ORNL researchersinvented a method to thermally process thin films and other ...
Plasma deposited diamond-like carbon films for large neutralarrays
To understand how large systems of neurons communicate, we need to develop methods for growing patterned networks of large numbers of neurons. We have found that diamond-like carbon thin films formed by energetic deposition from a filtered vacuum arc carbon plasma can serve as ''neuron friendly'' substrates for the growth of large neural arrays. Lithographic masks can be used to form patterns of diamond-like carbon, and regions of selective neuronal attachment can form patterned neural arrays. In the work described here, we used glass microscope slides as substrates on which diamond-like carbon was deposited. PC-12 rat neurons were then cultured on the treated substrates and cell growth monitored. Neuron growth showed excellent contrast, with prolific growth on the treated surfaces and very low growth on the untreated surfaces. Here we describe the vacuum arc plasma deposition technique employed, and summarize results demonstrating that the approach can be used to form large patterns of neurons.
Brown, I.G.; Blakely, E.A.; Bjornstad, K.A.; Galvin, J.E.; Monteiro, O.R.; Sangyuenyongpipat, S.
Thermionic energy conversion research analysis. Annual progress report. [Study on plasma arc-drop
This progress report summarizes the major results presented in ''Preliminary Report on Plasma Arc-Drop in Thermionic Energy Converters,'' (COO-2533-1), and includes additional discussions on the magnitude of the normalized plasma resistance required to achieve low arc-drop converter operation.
Lam, S.H.
Plasma deposited rider rings for hot displacer
A hot cylinder for a cryogenic refrigerator having two plasma spray deposited rider rings of a corrosion and abrasion resistant material provided in the rider ring grooves, wherein the rider rings are machined to the desired diameter and width after deposition. The rider rings have gas flow flats machined on their outer surface.
Kroebig, Helmut L. (Rolling Hills, CA)
Underwater cladding with laser beam and plasma arc welding
Two welding processes, plasma arc (transferred arc) (PTA) and laser beam, were investigated to apply cladding to austenitic stainless steels and Inconel 600. These processes have long been used to apply cladding layers , but the novel feature being reported here is that these cladding layers were applied underwater, with a water pressure equivalent to 24 m (80 ft). Being able to apply the cladding underwater is very important for many applications, including the construction of off-shore oil platforms and the repair of nuclear reactors. In the latter case, being able to weld underwater eliminates the need for draining the reactor and removing the fuel. Welding underwater in reactors presents numerous challenges, but the ability to weld without having to drain the reactor and remove the fuel provides a huge cost savings. Welding underwater in reactors must be done remotely, but because of the radioactive corrosion products and neutron activation of the steels, remote welding would also be required even if the reactor is drained and the fuel removed. In fact, without the shielding of the water, the remote welding required if the reactor is drained might be even more difficult than that required with underwater welds. Furthermore, as shall be shown, the underwater welds that the authors have made were of high quality and exhibit compressive rather than tensile residual stresses.
White, R.A.; Fusaro, R.; Jones, M.G.; Solomon, H.D. [General Electric Corporate Research and Development Center, Schenectady, NY (United States); Milian-Rodriguez, R.R. [GE Nuclear Energy, San Jose, CA (United States)
Method of operating a centrifugal plasma arc furnace
A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe{sub 3}O{sub 4}. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe{sub 2}O{sub 3}. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater. 3 figs.
Kujawa, S.T.; Battleson, D.M.; Rademacher, E.L. Jr.; Cashell, P.V.; Filius, K.D.; Flannery, P.A.; Whitworth, C.G.
Emission spectra analysis of arc plasma for synthesis of carbon nanostructures in various magnetic conditions
Arc discharge supported by the erosion of anode materials is one of the most practical and efficient methods to synthesize various high-quality carbon nanostructures. By introducing a non-uniform magnetic field in arc plasmas, high-purity single-walled carbon nanotubes (SWCNT) and large-scale graphene flakes can be obtained in a single step. In this paper, ultraviolet-visible emission spectra of arc in different spots under various magnetic conditions are analyzed to provide an in situ investigation for transformation processes of evaporated species and growth of carbon nanostructures in arc. Based on the arc spectra of carbon diatomic Swan bands, vibrational temperature in arc is determined. The vibrational temperature in arc center was measured around 6950 K, which is in good agreement with our simulation results. Experimental and simulation results suggest that SWCNT are formed in the arc periphery region. Transmission electronic microscope and Raman spectroscope are also employed to characterize the properties of carbon nanostructures.
Li Jian; Kundrapu, Madhusudhan; Shashurin, Alexey; Keidar, Michael [Department of Mechanical and Aerospace Engineering, George Washington University, Washington, DC 20052 (United States)
The evolution of ion charge states in cathodic vacuum arc plasmas: a review
Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after "Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources" appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the "noise" in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.
Arc Welding
...work surface Radiation from the arc Thermal conduction from the arc plasma to the workpiece The first two mechanisms constitute the major source of energy to the
Computational study of flow dynamics from a dc arc plasma jet
Plasma jets produced by direct-current (DC) non-transferred arc plasma torches, at the core of technologies ranging from spray coating to pyrolysis, present intricate dynamics due to the coupled interaction of fluid flow, thermal, and electromagnetic phenomena. The flow dynamics from an arc discharge plasma jet are investigated using time-dependent three-dimensional simulations encompassing the dynamics of the arc inside the torch, the evolution of the jet through the discharge environment, and the subsequent impingement of the jet over a flat substrate. The plasma is described by a chemical equilibrium and thermodynamic nonequilibrium (two-temperature) model. The numerical formulation of the physical model is based on a monolithic and fully-coupled treatment of the fluid and electromagnetic equations using a Variational Multiscale Finite Element Method. Simulation results uncover distinct aspects of the flow dynamics, including the jet forcing due to the movement of the electric arc, the prevalence of deviat...
Trelles, Juan Pablo
Carbon nanostructures production by AC arc discharge plasma process at atmospheric pressure
Carbon nanostructures have received much attention for a wide range of applications. In this paper, we produced carbon nanostructures by decomposition of benzene using AC arc discharge plasma process at atmospheric pressure. Discharge was carried out ...
Shenqiang Zhao; Ruoyu Hong; Zhi Luo; Haifeng Lu; Biao Yan
Microwave plasma chemical vapor deposition of nano-composite...
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plasma chemical vapor deposition of nano-composite CPt thin-films Title Microwave plasma chemical vapor deposition of nano-composite CPt thin-films Publication Type Journal...
Heat treatment of cathodic arc deposited amorphous hard carbon films
Amorphous hard carbon films of varying sp{sup 2}/sp{sup 3} fractions have been deposited on Si using filtered cathodic are deposition with pulsed biasing. The films were heat treated in air up to 550 C. Raman investigation and nanoindentation were performed to study the modification of the films caused by the heat treatment. It was found that films containing a high sp{sup 3} fraction sustain their hardness for temperatures at least up to 400 C, their structure for temperatures up to 500 C, and show a low thickness loss during heat treatment. Films containing at low sp{sup 3} fraction graphitize during the heat treatment, show changes in structure and hardness, and a considerable thickness loss.
Anders, S.; Ager, J.W. III; Brown, I.G. [and others
Optical Analysis Of The Vacuum Arc Plasma Generated In Cup-Shape Contacts
In this paper are presented the results of the optical analysis on the rotating arc plasma, generated in the vacuum low voltage circuit breaker with cup-shaped contacts. An adequate experimental setup was used for single shot time and spatial resolved spectroscopy in order to analyze the evolution of the vacuum arc plasma. Different current interruption situations are correlated with plasma spectral diagnosis. The study is aimed to contribute to a better understanding of the complex phenomena that take place in the interruption process of high currents that appears in the short-circuit regime of electrical networks.
Pavelescu, G.; Gherendi, F. [National Institute for Optoelectronics, Bucharest-Magurele (Romania); Pavelescu, D. ['Politehnica' University of Bucharest, Bucharest (Romania); Dumitrescu, G.; Anghelita, P. [Electrotechnical Institute, ICPE, Bucharest (Romania)
Mechanism of Synthesis of Ultra-Long Single Wall Carbon Nanotubes in Arc Discharge Plasma
In this project fundamental issues related to synthesis of single wall carbon nanotubes (SWNTs), which is relationship between plasma parameters and SWNT characteristics were investigated. Given that among plasma-based techniques arc discharge stands out as very advantageous in several ways (fewer defects, high flexibility, longer lifetime) this techniques warrants attention from the plasma physics and plasma technology standpoint. Both experimental and theoretical investigations of the plasma and SWNTs synthesis were conducted. Experimental efforts focused on plasma diagnostics, measurements of nanostructures parameters, and nanoparticle characterization. Theoretical efforts focused to focus on multi-dimensional modeling of the arc discharge and single wall nanotube synthesis in arc plasmas. It was demonstrated in experiment and theoretically that controlling plasma parameters can affect nanostucture synthesis altering SWNT properties (length and diameter) and leading to synthesis of new structures such as a few-layer graphene. Among clearly identified parameters affecting synthesis are magnetic and electric fields. Knowledge of the plasma parameters and discharge characteristics is crucial for ability to control synthesis process by virtue of both magnetic and electric fields. New graduate course on plasma engineering was introduced into curriculum. 3 undergraduate students were attracted to the project and 3 graduate students (two are female) were involved in the project. Undergraduate student from Historically Black University was attracted and participated in the project during Summer 2010.
Keidar, Michael [George Washington University] [George Washington University
Geochemical tracers of processes affecting the formation of seafloor hydrothermal fluids and deposits in the Manus back-arc basin
Systematic differences in trace element compositions (rare earth element (REE), heavy metal, metalloid concentrations) of seafloor vent fluids and related deposits from hydrothermal systems in the Manus back-arc basin ...
Craddock, Paul R
Measurement of total ion current from vacuum arc plasma sources
field is not to just change the plasma flux distribution but rather to increase the measured (electrical) ion current
Oks, Efim M.; Savkin, Konstantin P.; Yushkov, Georgiu Yu.; Nikolaev, Alexey G.; Anders, A.; Brown, Ian G.
Elements of arc welding
This paper looks at the following arc welding techniques: (1) shielded metal-arc welding; (2) submerged-arc welding; (3) gas metal-arc welding; (4) flux-cored arc welding; (5) electrogas welding; (6) gas tungsten-arc welding; and (7) plasma-arc welding.
Plasma implantation and deposition for advanced materials surface modification.
??The research work described in this thesis focuses on the physics of plasma implantation and deposition as well as the application of the technology to… (more)
Fu, King Yu (???)
A model of plasma discharges in pre-arcing regime for water treatment
It is presented a simulation study of a water treatment system based upon 1 kHz frequency plasma discharges in the pre-arcing regime produced within a coaxial cylinder reactor. The proposed computational model takes into consideration the three main ... Keywords: modelling, pulsed corona discharges, simulation, streamers
B. G. Rodríguez-Méndez; R. López-Callejas; R. Peńa-Eguiluz; A. Mercado-Cabrera; R. Valencia-Alvarado; S. R. Barocio; A. de la Piedad-Beneitez; J. S. Benítez-Read; J. O. Pacheco-Sotelo
NOREM Applications Guidelines: Procedures for Gas Tungsten Arc and Plasma Transferred Arc Welding of NOREM Cobalt-Free Hardfacing Al loys
Wire products have been successfully fabricated and new procedures developed for machine and manual gas tungsten arc welding (GTAW) of the iron-base NOREM hardfacing alloys. These developments enhance the attractiveness of NOREM alloys both in replacement valves and in field repairs of installed valves. This report describes the GTAW procedures and summarizes plasma transferred arc welding (PTAW) parameters for shop applications of NOREM alloys.
Mechanism of surface modification in the plasma-surface interaction in electrical arcs
Electrical sparks and arcs are plasma discharges that carry large currents and can strongly modify surfaces. This damage usually comes in the form of micrometer-sized craters and frozen-in liquid on the surface. Using a combination of experiments, plasma and atomistic simulation tools, we now show that the observed formation of deep craters and liquidlike features during sparking in vacuum is explained by the impacts of energetic ions, accelerated under the given conditions in the plasma sheath to kiloelectron volt energies, on surfaces. The flux in arcs is so high that in combination with kiloelectron volt energies it produces multiple overlapping heat spikes, which can lead to cratering even in materials such as Cu, where a single heat spike normally does not.
Timko, H.; Djurabekova, F.; Nordlund, K.; Costelle, L.; Matyash, K.; Schneider, R.; Toerklep, A.; Arnau-Izquierdo, G.; Descoeudres, A.; Calatroni, S.; Taborelli, M.; Wuensch, W. [CERN, CH-1211 Geneve 23 (Switzerland); and Helsinki Institute of Physics and Department of Physics, University of Helsinki, P.O. Box 43, FIN-00014 Helsinki (Finland); Helsinki Institute of Physics and Department of Physics, University of Helsinki, P.O. Box 43, FIN-00014 Helsinki (Finland); Department of Physics, University of Helsinki, P.O. Box 43, FIN-00014 Helsinki (Finland); Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); CERN, CH-1211 Geneve 23 (Switzerland)
The Radiative Transfer Of CH{sub 4}-N{sub 2} Plasma Arc
Any physical modelling of a circuit-breaker arc therefore requires an understanding of the radiated energy which is taken into account in the form of a net coefficient. The evaluation of the net emission coefficient is performed by the knowledge of the chemical plasma composition and the resolution of the radiative transfer equation. In this paper, the total radiation which escapes from a CH{sub 4}-N{sub 2} plasma is calculated in the temperature range between 5000 and 30000K on the assumption of a local thermodynamic equilibrium and we have studied the nitrogen effect in the hydrocarbon plasmas.
Benallal, R. [Theoretical physics Laboratory, Physics Department of University Aboubekr Belkaied Tlemcen 13000 (Algeria); Liani, B. [Science Faculty, Hassiba Benbouali University, Chlef 02000 (Algeria)
Railguns and plasma accelerators: arc armatures, pulse power sources and US patents
Railguns and plasma accelerators have the potential for use in many basic and applied research projects, such as in creating high-pressures for equation-of-state studies and in impact fusion. A brief review of railguns and plasma accelerators with references is presented. Railgun performance is critically dependent on armature operation. Plasma arc railgun armatures are addressed. Pulsed power supplies for multi-stage railguns are considered. This includes brief comments on the compensated pulsed alternator, or compulsator, rotating machinery, and distributed energy sources for railguns. References are given at the end of each section. Appendix A contains a brief review of the US Patents on multi-staging techniques for electromagnetic accelerators, plasma propulsion devices, and electric guns.
Friedrich, O.M. Jr.
Formation of NOx precursors during Chinese pulverized coal pyrolysis in an arc plasma jet
The formation of NOx precursors (HCN and NH{sub 3}) from the pyrolysis of several Chinese pulverized coals in an arc plasma jet was investigated through both thermodynamic analysis of the C-H-O-N system and experiments. Results of thermodynamic analysis show that the dominant N-containing gaseous species is HCN together with a small amount of ammonia above the temperature of 2000 K. The increase of H content advances the formation of HCN and NH{sub 3}, but the yields of HCN and NH{sub 3} are decreased with a high concentration of O in the system. These results are accordant with the experimental data. The increasing of input power promotes the formation of HCN and NH{sub 3} from coal pyrolysis in an arc plasma jet. Tar-N is not formed during the process. The yield of HCN changes insignificantly with the changing of the residence time of coal particles in the reactor, but that of NH{sub 3} decreases as residence times increase because of the relative instability at high temperature. Adsorption and gasification of CO{sub 2} on the coal surface also can restrain the formation of HCN and NH{sub 3} compare to the results in an Ar plasma jet. Yields of HCN and NH{sub 3} are sensitive to the coal feeding rate, indicating that NOx precursors could interact with the nascent char to form other N-containing species. The formation of HCN and NH{sub 3} during coal pyrolysis in a H{sub 2}/Ar plasma jet are not dependent on coal rank. The N-containing gaseous species is released faster than others in the volatiles during coal pyrolysis in an arc plasma jet, and the final nitrogen content in the char is lower than that in the parent coal, which it is independent of coal type. 16 refs., 9 figs., 1 tab.
Wei-ren Bao; Jin-cao Zhang; Fan Li; Li-ping Chang [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology
Low temperature plasma enhanced chemical vapor deposition of silicon oxide films using disilane and nitrous oxide
Keywords: disilane, low temperature, nitrous oxide, plasma enhanced chemical vapor deposition, silicon oxide
Juho Song; G. S. Lee; P. K. Ajmera
Metal-containing tetrahedral amorphous carbon films wereproduced by dual filtered cathodic vacuum arc plasma sources operatedinsequentially pulsed mode. Negatively pulsed bias was applied to thesubstrate when carbon plasma was generated, whereas it was absentwhen themolybdenum plasma was presented. Film thickness was measured afterdeposition by profilometry. Glass slides with silver padswere used assubstrates for the measurement of the sheet resistance. Themicrostructure and composition of the films were characterizedbyRamanspectroscopy and Rutherford backscattering, respectively. It was foundthat the electrical resistivity decreases with an increaseof the Mocontent, which can be ascribed to an increase of the sp2 content and anincrease of the sp2 cluster size.
Pasaja, Nitisak; Sansongsiri, Sakon; Intasiri, Sawate; Vilaithong, Thiraphat; Anders, Andre
Characterization of the TEXTOR plasma edge using deposition probe techniques
Carbon and single crystal silicon passive deposition probes were used to measure the characteristics of the plasma edge region of the TEXTOR tokamak. Analysis of the probes was done by Rutherford backscattering for impurities and nuclear reaction analysis and elastic recoil detection for hydrogen isotopes. Plasma fluxes and energies in the edge were measured using these techniques. The principal impurities in the plasma edge were determined and their behavior as a function of time and position was measured. Measurements were also made of in situ erosion rates. The results are compared with independent measurements of other plasma parameters to study possible impurity introduction mechanisms.
Zuhr, R.A.
MeV-ion beam analysis of the interface between filtered cathodic arc-deposited a-carbon and single crystalline silicon
Amorphous carbon (a-C) films were deposited on Si(100) wafers by a filtered cathodicvacuum arc (FCVA) plasma source. A negative electrical bias was applied tothe silicon substrate in order to control the incident energy of carbon ions. Effects ofthe electrical bias on the a-C/Si interface characteristics were investigated by usingstandard Rutherford backscattering spectrometry (RBS) in the channeling modewith 2.1-MeV He2+ ions. The shape of the Si surface peaks of the RBS/channelingspectra reflects the degree of interface disorder due to atomic displacement fromthe bulk position of the Si crystal. Details of the analysis method developed aredescribed. It was found that the width of the a-C/Si interface increases linearlywith the substrate bias voltage but not the thickness of the a-C film.
Kamwanna, T.; Pasaja, N.; Yu, L.D.; Vilaithong, T.; Anders, A.; Singkarat, S.
High quality ZnO:Al transparent conducting oxide films synthesized by pulsed filtered cathodic arc deposition
Aluminum-doped zinc oxide, ZnO:Al or AZO, is a well-known n-type transparent conducting oxide with great potential in a number of applications currently dominated by indium tin oxide (ITO). In this study, the optical and electrical properties of AZO thin films deposited on glass and silicon by pulsed filtered cathodic arc deposition are systematically studied. In contrast to magnetron sputtering, this technique does not produce energetic negative ions, and therefore ion damage can be minimized. The quality of the AZO films strongly depends on the growth temperature while only marginal improvements are obtained with post-deposition annealing. The best films, grown at a temperature of about 200?C, have resistivities in the low to mid 10-4 Omega cm range with a transmittance better than 85percent in the visible part of the spectrum. It is remarkable that relatively good films of small thickness (60 nm) can be fabricated using this method.
Anders, Andre; Lim, Sunnie H.N.; Yu, Kin Man; Andersson, Joakim; Rosen, Johanna; McFarland, Mike; Brown, Jeff
Nanostructured materials are rarely synthesized with appropriate phase and/or morphology. In this study, critical additional of as-synthesized nanostructured materials, such as annealing and/or activation of dopants, are addressed using infrared plasma arc lamps (PAL) over areas as large as 1,000 cm2. The broad spectral range of the PAL and the spectral variation of light absorption in nanostructured materials make the selection of processing parameters extremely difficult, posing a major technological barrier. In this study, the measurement of the surface temperature using various techniques for ZnO films on crystalline silicon wafers is discussed. An energy transport model for the simulation of rapid thermal processing using PAL is presented. The experimental and computational results show that the surface temperature cannot be measured directly and that computer simulation results are an effective tool for obtaining accurate data on processing temperatures.
Sabau, Adrian S [ORNL; Dinwiddie, Ralph Barton [ORNL; Xu, Jun [ORNL; Angelini, Joseph Attilio [ORNL; Harper, David C [ORNL
Atmospheric Plasma Deposition of Diamond-like Carbon Coatings
DLC coatings in a low-pressure environment. For example, ion beam processes are widely utilized since the ion bombardment is thought to promote denser sp3-bonded carbon networks. Other processes, such as sputtering, are better suited for coating large parts [29,30,44]. However, the deposition of DLC in a vacuum system has several disadvantages, including high equipment cost and restrictions on the size and shape of material that may be treated. The deposition of DLC at atmospheric pressure has been demonstrated by several researchers. Izake, et al [53] and Novikov and Dymont [54] have demonstrated an electrochemical process that is carried out with organic compounds such as methanol and acetylene dissolved in ammonia. This process requires that the substrates be immersed in the liquid [53-54]. The atmospheric pressure deposition of DLC was also demonstrated by Kulik, et al. utilizing a plasma torch. However, this process requires operating temperatures in excess of 800 oC [55]. In this report, we investigate the deposition of diamond-like carbon films using a low temperature, atmospheric pressure plasma-enhanced chemical vapor deposition (PECVD) process. The films were characterized by solid-state carbon-13 nuclear magnetic resonance (13C NMR) and found to have a ratio of sp2 to sp3 carbon of 43 to 57%. The films were also tested for adhesion, coefficient of friction, and dielectric strength.
Ladwig, Angela
Prediction of plasma enhanced deposition process using GA-Optimized GRNN
A genetic algorithm (GA)-based optimization of generalized regression neural network (GRNN) was presented and evaluated with statistically characterized plasma deposition data. The film characteristics to model were deposition rate and positive charge ...
Byungwhan Kim; Dukwoo Lee; Seung Soo Han
Investigation of the effect of welding parameters on weld quality of plasma arc keyhole welding of structural steels
In the present investigation, the individual and interactive effects of the main welding parameters on weld quality of plasma arc keyhole welding of conventional structural steel, high strength microalloyed steel and strong formable microalloyed steel have been examined using welding of butt joints with a square groove in various welding positions, and welding of joint roots with a single-V-groove and the root face in the flat position. The most important welding parameters are welding current, welding speed and welding gases, especially plasma gas flow rate. Welding parameter combinations producing the best quality welds are presented. It is shown that it is possible to achieve defect-free high-quality welds with good strength and toughness properties, but the allowable range of variation of welding parameters, especially for the highest weld quality, is narrow. An argonhydrogen mixture for the plasma gas together with argon as shielding and backing gases give the best results with respect to weld quality.
Martikainen, J.K.; Moisio, T.J.I. (Lappeenranta Univ. of Technology, Lappeenranta (Finland). Welding Technology Lab.)
This document is a final report covering work performed under Contract No. DE-FG02-99ER82911 from the Department of Energy under a SBIR Phase II Program. Wear resistant, hard coatings can play a vital role in many engineering applications. The primary goal of this project was to develop coatings containing boron and carbon with hardness greater than 30 GPa and evaluate these coatings for machining applications. UES has developed a number of carbon and boron containing coatings with hardness in the range of 34 to 65 GPa using a combination of filtered cathodic arc and magnetron sputtering. The boron containing coatings were based on TiB2, TiBN, and TiBCN, while the carbon containing coatings ere TiC+C and hydrogen free diamond-like-carbon. Machining tests were performed with single and multilayer coated tools. The turning and milling tests were run at TechSolve Inc., under a subcontract at Ohio State University. Significant increases in tool lives were realized in end milling of H-13 die steel (8X) and titanium alloy (80%) using the TiBN coating. A multilayer TiBN/TiN performed the best in end-milling of highly abrasive Al-Si alloys. A 40% increase in life over the TiAlN benchmark coating was found. Further evaluations of these coatings with commercialization partners are currently in progress.
Bhattacharya, Rabi S.
Tunable, self-powered integrated arc plasma-melter vitrification system for waste treatment and resource recovery
The present invention provides a relatively compact self-powered, tunable waste conversion system and apparatus which has the advantage of highly robust operation which provides complete or substantially complete conversion of a wide range of waste streams into useful gas and a stable, nonleachable solid product at a single location with greatly reduced air pollution to meet air quality standards. The system provides the capability for highly efficient conversion of waste into high quality combustible gas and for high efficiency conversion of the gas into electricity by utilizing a high efficiency gas turbine or by an internal combustion engine. The solid product can be suitable for various commercial applications. Alternatively, the solid product stream, which is a safe, stable material, may be disposed of without special considerations as hazardous material. In the preferred embodiment of the invention, the arc plasma furnace and joule heated melter are formed as a fully integrated unit with a common melt pool having circuit arrangements for the simultaneous independently controllable operation of both the arc plasma and the joule heated portions of the unit without interference with one another. The preferred configuration of this embodiment of the invention utilizes two arc plasma electrodes with an elongated chamber for the molten pool such that the molten pool is capable of providing conducting paths between electrodes. The apparatus may additionally be employed with reduced or without further use of the gases generated by the conversion process. The apparatus may be employed as a self-powered or net electricity producing unit where use of an auxiliary fuel provides the required level of electricity production.
Titus, Charles H. (Newtown Square, PA); Cohn, Daniel R. (Chestnuthill, MA); Surma, Jeffrey E. (Kennewick, WA)
Departures from local thermodynamic equilibrium in cutting arc plasmas derived from electron and gas density measurements using a two-wavelength quantitative Schlieren technique
A two-wavelength quantitative Schlieren technique that allows inferring the electron and gas densities of axisymmetric arc plasmas without imposing any assumption regarding statistical equilibrium models is reported. This technique was applied to the study of local thermodynamic equilibrium (LTE) departures within the core of a 30 A high-energy density cutting arc. In order to derive the electron and heavy particle temperatures from the inferred density profiles, a generalized two-temperature Saha equation together with the plasma equation of state and the quasineutrality condition were employed. Factors such as arc fluctuations that influence the accuracy of the measurements and the validity of the assumptions used to derive the plasma species temperature were considered. Significant deviations from chemical equilibrium as well as kinetic equilibrium were found at elevated electron temperatures and gas densities toward the arc core edge. An electron temperature profile nearly constant through the arc core with a value of about 14000-15000 K, well decoupled from the heavy particle temperature of about 1500 K at the arc core edge, was inferred.
Prevosto, L.; Mancinelli, B. [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto 2600, Santa Fe (Argentina); Artana, G. [Laboratorio de Fluidodinamica, Departamento Ing. Mecanica, Facultad de Ingenieria (UBA), Paseo Colon 850, C1063ACV, Buenos Aires (Argentina); Kelly, H. [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto 2600, Santa Fe (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales (UBA), Instituto de Fisica del Plasma (CONICET), Ciudad Universitaria, Pab. I, 1428 Buenos Aires (Argentina)
Mo-containing tetrahedral amorphous carbon deposited by dual filtered cathodic vacuum arc with selective pulsed bias voltage
was found that the electrical resistivity decreases with ancathodic vacuum arc; electrical resistivity; profilometry;elastic modulus, high electrical resistivity, low friction
Physical characteristics of gliding arc discharge plasma generated in a laval nozzle
The dynamic behavior of gliding arc discharge generated in a Laval nozzle has been investigated by electrical diagnostics and a high-speed camera. The results show that the voltage waveform keeps the initial shape as the gas flow rate is small, while it becomes less stable with increasing flow rate. During the first half of a cycle, the voltage rises and after that it decreases. In nitrogen and oxygen, the break down voltage for the arc is between 3.3 and 5.5 kV, while it is between 3.3-7.5 kV in air. The waveform of current I remains almost stable; and for nitrogen and oxygen, the maximum value of current I is between 0.28 and 0.46 A. With increasing flow rate, the power consumption in air first increases and then decreases; it remains in the range of 110-217 W, and gradually increases in nitrogen and oxygen. The power consumption in oxygen is lower than that in nitrogen; the input of the energy density decreases with increasing flow rate for all the three gases. The development of the arc is tracked and recorded by a high-speed camera. The cycle is stable at 10 ms for flow rates up to 1 m{sup 3} h{sup -1}. At a higher flow rate, the cycle becomes unstable.
Lu, S. Y.; Sun, X. M.; Li, X. D.; Yan, J. H. [State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027 (China); Du, C. M. [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)
Effect of ion mass and charge state on transport of vacuum ARC plasmas through a biased magnetic filter
The effect of ion mass and charge state on plasma transport through a 90{sup o}-curved magnetic filter is experimentally investigated using a pulsed cathodic arc source. Graphite, copper, and tungsten were selected as test materials. The filter was a bent copper coil biased via the voltage drop across a low-ohm, ''self-bias'' resistor. Ion transport is accomplished via a guiding electric field, whose potential forms a ''trough'' shaped by the magnetic guiding field of the filter coil. Evaluation was done by measuring the filtered ion current and determination of the particle system coefficient, which can be defined as the ratio of filter ion current, divided by the mean ion charge state, to the arc current. It was found that the ion current and particle system coefficient decreased as the mass-to-charge ratio of ions increased. This result can be qualitatively interpreted by a very simply model of ion transport that is based on compensation of the centrifugal force by the electric force associated with the guiding potential trough.
Byon, Eungsun; Kim, Jong-Kuk; Kwon, Sik-Chol; Anders, Andre
Standard Practice for Measuring Plasma Arc Gas Enthalpy by Energy Balance
1.1 This practice covers the measurement of total gas enthalpy of an electric-arc-heated gas stream by means of an overall system energy balance. This is sometimes referred to as a bulk enthalpy and represents an average energy content of the test stream which may differ from local values in the test stream. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
American Society for Testing and Materials. Philadelphia
Improved structural and electrical properties of thin ZnO:Al films by dc filtered cathodic arc deposition
that nearly the entire solar spectrum can be transmitted,and nearly the entire solar spectrum is transmitted. Thisspectrum. Therefore, arc-grown AZO is potentially suitable for high efficiency, multijunction solar
Zhu, Yuankun
Method For Plasma Source Ion Implantation And Deposition For Cylindrical Surfaces
Uniform ion implantation and deposition onto cylindrical surfaces is achieved by placing a cylindrical electrode in coaxial and conformal relation to the target surface. For implantation and deposition of an inner bore surface the electrode is placed inside the target. For implantation and deposition on an outer cylindrical surface the electrode is placed around the outside of the target. A plasma is generated between the electrode and the target cylindrical surface. Applying a pulse of high voltage to the target causes ions from the plasma to be driven onto the cylindrical target surface. The plasma contained in the space between the target and the electrode is uniform, resulting in a uniform implantation or deposition of the target surface. Since the plasma is largely contained in the space between the target and the electrode, contamination of the vacuum chamber enclosing the target and electrodes by inadvertent ion deposition is reduced. The coaxial alignment of the target and the electrode may be employed for the ion assisted deposition of sputtered metals onto the target, resulting in a uniform coating of the cylindrical target surface by the sputtered material. The independently generated and contained plasmas associated with each cylindrical target/electrode pair allows for effective batch processing of multiple cylindrical targets within a single vacuum chamber, resulting in both uniform implantation or deposition, and reduced contamination of one target by adjacent target/electrode pairs.
Fetherston, Robert P. (Madison, WI), Shamim, Muhammad M. (Madison, WI), Conrad, John R. (Madison, WI)
Lithium phosphorous oxynitride films synthesized by a plasma-assisted directed vapor deposition approach
Lithium phosphorous oxynitride films synthesized by a plasma-assisted directed vapor deposition vapor deposition approach has been explored for the synthesis of lithium phosphorous oxynitride Lipon the ionic transport properties of these films. This enabled the synthesis of electrolyte films with lithium
Wadley, Haydn
Using the Centrifugal Method for the Plasma-Arc Vitrification of Waste
... from the first experiments in 1985 to occupy a niche in the waste-treatment market. ... The availability of energy at high temperatures is much greater for electric .... Retech Plasma Centrifugal Furnace Application Analysis Report (
Characteristics of Polymer Films Deposited via Microwave Plasma ...
Abstract Scope, Thin films were deposited on both Al and glass substrates at RT by MPECVD using benzene as precursor. Surface and physical properties of ...
Novel Properties of Zn Coating Deposited by Electro-Plasma ...
Abstract Scope, State of the art Electro-plasma technology (EPT) was ... was characterized by Electron Microscopy, Energy Dispersive Spectroscopy, X-ray ...
Puzzling differences in bismuth and lead plasmas: evidence for the significant role of neutrals in cathodic vacuum arcs
ionization energy (eV) Electrical resistivity, (n? m) @ 20°Crod, the given electrical resistivity, and an arc current of
Anders, Andre; Yushkov, Georgy Yu.
Angular emission of ions and mass deposition from femtosecond and nanosecond laser-produced plasmas
We investigated the angular distribution of ions and atoms emanating from femto- and nanosecond laser-produced metal plasmas under similar laser fluence conditions. For producing plasmas, aluminum targets are ablated in vacuum employing pulses from a Ti:Sapphire ultrafast laser (40 fs, 800 nm) and an Nd:YAG laser (6 ns, 1064 nm). The angular distribution of ion emission as well as the kinetic energy distribution is characterized by a Faraday cup, while a quartz microbalance is used for evaluating deposited mass. The ion and deposited mass features showed that fs laser ablated plasmas produced higher kinetic energy and more mass per pulse than ns plumes over all angles. The ion flux and kinetic energy studies show fs laser plasmas produce narrower angular distribution while ns laser plasmas provide narrower energy distribution.
Verhoff, B.; Harilal, S. S.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)
Microlaminate composite structures by low pressure plasma spray deposition
The low pressure plasma spray (LPPS) process has been utilized in the development and fabrication of metal/metal, metal/carbide, and metal/oxide composite structures; including particulate dispersion and both continuous and discontinuous laminates. This report describes the LPPS process and the development of copper/tungsten microlaminate structures utilizing this processing method. Microstructures and mechanical properties of the Cu/W composites are compared to conventionally produced constituent material properties. 4 refs., 6 figs., 2 tabs.
Castro, R.G.; Stanek, P.W.
Design of Superhydrophobic Paper/Cellulose Surfaces via Plasma Enhanced Etching and Deposition
agents have been added to pulp slur- ries to yield hydrophobic paper surfaces [3]. In recent decades to the paper forming process. Commercial copy paper substrates, "Premium white copy paper", were obtained fromDesign of Superhydrophobic Paper/Cellulose Surfaces via Plasma Enhanced Etching and Deposition
Breedveld, Victor
only. Fig.2 (a) Electrical resistivity of ta-C:Mo films as aC plasma pulses; (b) Electrical resistivity of the ta-C:MoIt found that the electrical resistivity decreases with an
Pasaja, Nitisak; Sansongsiri, Sakon; Anders, Andre; Vilaithong, Thiraphat; Intasiri, Sawate
An Evaluation of Atmospheric-pressure Plasma for the Cost-Effective Deposition of Antireflection Coatings
Atmospheric-pressure plasma deposition (APPD) has previously been used to deposit various functional materials including polymeric surface modification layers, transparent conducting oxides, and photo catalytic materials. For many plasma polymerized coatings, reaction occurs via free radical mechanism where the high energy electrons from the plasma activate the olefinic carbon-carbon double bonds - a typical functional group in such precursors. The precursors for such systems are typically inexpensive and readily available and have been used in vacuum PECVD previously. The objectives are to investigate: (1) the effect of plasma power, gas composition and substrate temperature on the Si-based film properties using triethylsilane(TES) as the precursor; and (2) the chemical, mechanical, and optical properties of several experimental matrices based on Design of Experiment (DOE) principals. A simple APPD route has been utilized to deposit Si based films from an inexpensive precursor - Triethylsilane (TES). Preliminary results indicates formation of Si-C & Si-O and Si-O, Si-C & Si-N bonds with oxygen and nitrogen plasmas respectively. N{sub 2}-O{sub 2} plasma showed mixed trend; however oxygen remains a significant portion of all films, despite attempts to minimize exposure to atmosphere. SiN, SiC, and SiO ratios can be modified by the reaction conditions resulting in differing film properties. SE studies revealed that films with SiN bond possess refractive index higher than coatings with Si-O/Si-C bonds. Variable angle reflectance studies showed that SiOCN coatings offer AR properties; however thickness and refractive index optimization of these coatings remains necessary for application as potential AR coatings.
Rob Sailer; Guruvenket Srinivasan; Kyle W. Johnson; Douglas L. Schulz
Magnetically controlled deposition of metals using gas plasma. Grant final report, January 1994--September 1997
This document reports the results of DOE grant DE-FE07-93ID3220 to the University of Idaho. The subject grant is the first phase of a project that has the objective to develop a method of spraying materials on a substrate in a controlled manner to eliminate the waste and hazardous material generation inherent in present plating processes. The project is considering plasma spraying of metal on a substrate using magneto-hydrodynamics to control the plasma/metal stream. The process being developed is considering the use of commercially available plasma torches to generate the plasma/metal stream. The plasma stream is collimated and directed using magnetic forces to the extent required for precise control of the deposition material. The plating process may be accomplished without waste and without generating hazardous waste. The project will be completed in phases. Phase one of the project, the subject of this grant, is the development of an analytical model that can be used to determine the feasibility of the process and to design a laboratory scale demonstration unit. The results of this phase of the project will provide clear data to demonstrate the theoretical feasibility of building and testing a laboratory demonstration unit. The contracted time is complete, and the research is still continuing. This report provides the results obtained to date. As the model and calculations are completed those results will also be provided.
A comparison of diamond growth rate using in-liquid and conventional plasma chemical vapor deposition methods
In order to make high-speed deposition of diamond effective, diamond growth rates for gas-phase microwave plasma chemical vapor deposition and in-liquid microwave plasma chemical vapor deposition are compared. A mixed gas of methane and hydrogen is used as the source gas for the gas-phase deposition, and a methanol solution of ethanol is used as the source liquid for the in-liquid deposition. The experimental system pressure is in the range of 60-150 kPa. While the growth rate of diamond increases as the pressure increases, the amount of input microwave energy per unit volume of diamond is 1 kW h/mm{sup 3} regardless of the method used. Since the in-liquid deposition method provides a superior cooling effect through the evaporation of the liquid itself, a higher electric input power can be applied to the electrodes under higher pressure environments. The growth rate of in-liquid microwave plasma chemical vapor deposition process is found to be greater than conventional gas-phase microwave plasma chemical vapor deposition process under the same pressure conditions.
Takahashi, Yoshiyuki; Toyota, Hiromichi; Nomura, Shinfuku; Mukasa, Shinobu [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Inoue, Toru [Geodynamics Research Center, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan)
Time-resolved diagnostics of excimer laser-generated ablation plasmas used for pulsed laser deposition
Characteristics of laser plasmas used for pulsed laser deposition (PLD) of thin films are examined with four in situ diagnostic techniques: Optical emission spectroscopy, optical absorption spectroscopy, ion probe studies, and gated ICCD (intensified charge-coupled-device array) fast photography. These four techniques are complementary and permit simultaneous views of the transport of ions, excited states, ground state neutrals and ions, and hot particulates following KrF laser ablation of YBCO, BN, graphite and Si in vacuum and background gases. The implementation and advantages of the four techniques are first described in order to introduce the key features of laser plasmas for pulsed laser deposition. Aspects of the interaction of the ablation plume with background gases (i.e., thermalization, attenuation, shock formation) and the collision of the plasma plume with the substrate heater are then summarized. The techniques of fast ICCD photography and gated photon counting are then applied to investigate the temperature, velocity, and spatial distribution of hot particles generated during KrF ablation of YBCO, BN, Si and graphite. Finally, key features of fast imaging of the laser ablation of graphite into high pressure rare gases are presented in order to elucidate internal reflected shocks within the plume, redeposition of material on a surface, and formation of hot nanoparticles within the plume.
Geohegan, D.B.
Plasma Enhanced Chemical Vapor Deposition on Living Substrates: Development, Characterization, and Biological Applications
This dissertation proposed the idea of "plasma-enhanced chemical vapor deposition on living substrates (PECVD on living substrates)" to bridge the gap between the thin film deposition technology and the biological and living substrates. This study focuses on the establishment of the knowledge and techniques necessary to perform "PECVD on living substrates" and contains three main aspects: development, characterization, and biological applications. First, a PECVD tool which can operate in ambient air and at low temperature was developed using a helium dielectric barrier discharge jet (DBD jet). It was demonstrated that various materials, such as polymeric, metallic, and composite films, can be readily synthesized through this technique. Second, the PMMA and copper films deposited using DBD jets were characterized. High-rate (22 nm/s), low-temperature (39 şC) PMMA deposition was achieved and the film surface morphology can be tailored by altering the discharge power. Conductive copper films with an electrical resistivity lower than 1×10-7 ohm-m were obtained through hydrogen reduction. Both PMMA and copper films can be grown on temperature-sensitive substrates, such as plastics, pork skin, and even fingernail. The electrical, optical, and imaging characterization of the DBD jets was also conducted and several new findings were reported. Multiple short-duration current pulses instead of only one broad pulse per half voltage cycle were observed when a dielectric substrate was employed. Each short-duration current pulse is induced by a leading ionization wave followed by the formation of a plasma channel. Precursor addition further changed the temporal sequence of the pulses. An increase in the power led to a mode change from a diffuse DBD jet to a concentrated one. This mode change showed significant dependence on the precursor type, tube size, and electrode configuration. These findings regarding the discharge characteristics can thus facilitate the development of DBD-jet operation strategies to improve the deposition efficacy. Finally, this technique was used to grow PMMA films onto agar to demonstrate one of its potential biological applications: sterile bandage deposition. The DBD jet with the film depositing ability enabled the surface to be not only efficiently sanitized but also protected by a coating from being reached by bacteria.
Tsai, Tsung-Chan 1982-
The Mechanical Properties of Alumina Films Formed by Plasma Deposition and by Ion Irradiation of Sapphire
This paper examines the correlation between mechanical properties and the density, phase, and hydrogen content of deposited alumina layers, and compares them to those of sapphire and amorphous alumina synthesized through ion-beam irradiation of sapphire. Alumina films were deposited using electron beam evaporation of aluminum and co-bombardment with O{sub 2}{sup +} ions (30-230 eV) from an electron cyclotron resonance (ECR) plasma. The H content and phase were controlled by varying the deposition temperature and the ion energy. Sapphire was amorphized at 84 K by irradiation with Al and O ions (in stoichiometric ratio) to a defect level of 4 dpa in order to form an amorphous layer 370 nm thick. Nanoindentation was performed to determine the elastic modulus, yield strength and hardness of all materials. Sapphire and amorphized sapphire have a higher density and exhibit superior mechanical properties in comparison to the deposited alumina films. Density was determined to be the primary factor affecting the mechanical properties, which showed only a weak correlation to the hydrogen content.
Barbour, J.C.; Follstaedt, D.M.; Knapp, J.A.; Linam, D.L.; Mayer, T.M.; Minor, K.G.
Plasma enhanced chemical vapor deposition (PECVD) method of forming vanadium oxide films and vanadium oxide thin-films prepared thereby
A method is disclosed of forming a vanadium oxide film on a substrate utilizing plasma enhanced chemical vapor deposition. The method includes positioning a substrate within a plasma reaction chamber and then forming a precursor gas comprised of a vanadium-containing chloride gas in an inert carrier gas. This precursor gas is then mixed with selected amounts of hydrogen and oxygen and directed into the reaction chamber. The amounts of precursor gas, oxygen and hydrogen are selected to optimize the final properties of the vanadium oxide film An rf plasma is generated within the reaction chamber to chemically react the precursor gas with the hydrogen and the oxygen to cause deposition of a vanadium oxide film on the substrate while the chamber deposition pressure is maintained at about one torr or less. Finally, the byproduct gases are removed from the plasma reaction chamber.
Zhang, Ji-Guang (Golden, CO); Tracy, C. Edwin (Golden, CO); Benson, David K. (Golden, CO); Turner, John A. (Littleton, CO); Liu, Ping (Lakewood, CO)
Plasma-enhanced atomic layer deposition and etching of high-k gadolinium oxide
Atomic layer deposition (ALD) of high-quality gadolinium oxide thin films is achieved using Gd(iPrCp){sub 3} and O{sub 2} plasma. Gd{sub 2}O{sub 3} growth is observed from 150 to 350 deg. C, though the optical properties of the film improve at higher temperature. True layer-by-layer ALD growth of Gd{sub 2}O{sub 3} occurred in a relatively narrow window of temperature and precursor dose. A saturated growth rate of 1.4 A/cycle was observed at 250 deg. C. As the temperature increases, high-quality films are deposited, but the growth mechanism appears to become CVD-like, indicating the onset of precursor decomposition. At 250 deg. C, the refractive index of the film is stable at {approx}1.80 regardless of other deposition conditions, and the measured dispersion characteristics are comparable to those of bulk Gd{sub 2}O{sub 3}. XPS data show that the O/Gd ratio is oxygen deficient at 1.3, and that it is also very hygroscopic. The plasma etching rate of the ALD Gd{sub 2}O{sub 3} film in a high-density helicon reactor is very low. Little difference is observed in etching rate between Cl{sub 2} and pure Ar plasmas, suggesting that physical sputtering dominates the etching. A threshold bias power exists below which etching does not occur; thus it may be possible to etch a metal gate material and stop easily on the Gd{sub 2}O{sub 3} gate dielectric. The Gd{sub 2}O{sub 3} film has a dielectric constant of about 16, exhibits low C-V hysteresis, and allows a 50 x reduction in gate leakage compared to SiO{sub 2}. However, the plasma enhanced atomic layer deposition (PE-ALD) process causes formation of an {approx}1.8 nm SiO{sub 2} interfacial layer, and generates a fixed charge of -1.21 x 10{sup 12} cm{sup -2}, both of which may limit use of PE-ALD Gd{sub 2}O{sub 3} as a gate dielectric.
Vitale, Steven A.; Wyatt, Peter W.; Hodson, Chris J. [MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420 (United States); Oxford Instruments Plasma Technology, Yatton, Bristol, BS49 4AP (United Kingdom)
Magnetically controlled deposition of metals using gas plasma. Quarterly progress report, January 1997--March 1997
Thin layers of secondary material are plated on substrates either by plating or spraying processes. Plating operations produce large amounts of hazardous liquid waste. Spraying, while one of the less waste intensive methods, produces {open_quotes}over spray,{close_quotes} or waste that is a result of uncontrolled nature of the spray stream. In many cases the over spray may produce a hazardous waste, requiring special processing. Spray coating is a mature process with many uses. Material can be deposited utilizing spraying technology in three basic ways: {open_quotes}Flame spraying{close_quotes}, direct spraying of molten metals and/or plasma spraying. This project is directed at controlling the plasma spraying process and thereby minimizing the waste generated in that process. The proposed process will utilize a standard plasma spray gun with the addition of magnetic fields to focus and control the plasma. In order to keep development cost at a minimum, the project was organized in phases. The first and current phase involves developing an analytical model that will prove the concept and be used to design a prototype. Analyzing the process and using the analysis has the potential to generate significant hardware cost savings.
[ital In] [ital situ] infrared measurements of film and gas properties during the plasma deposition of amorphous hydrogenated silicon
This research has performed preliminary [ital in] [ital situ] Fourier transform infrared (FTIR) measurements during the plasma deposition of amorphous silicon ([ital a]-Si:H). Experiments demonstrate both gas phase and film measurements within a simple SiH[sub 4] plasma reactor using a specially modified FTIR spectrometer. Films are deposited on substrates of either gold (mirror finish) or stainless steel (matte finish). In particular, [ital in] [ital situ] emission/reflection FTIR of the film yields information about surface temperature, film thickness, and film composition. We have measured surface temperature to [plus minus]5 K and detected the onset of poor film growth at a thickness of 500--1000 A using the 2080 cm[sup [minus]1] absorption feature. A simple model for the reflectance of a film on a metal is employed to determine the thickness of the films. [ital In] [ital situ] emission/transmission FTIR of the plasma determines the gas composition and average gas temperature. Measurements show that the silane conversion is [similar to]11% within the plasma region for a typical deposition at 250 [degree]C and roughly doubles for a deposition at room temperature. The FTIR spectra show that most of this converted silane reappears as disilane (Si[sub 2]H[sub 6]). Before starting the plasma, the silane gas is [similar to]30 K cooler than the nominal substrate temperature of 250 [degree]C; starting the plasma raises the average temperature another 20 [degree]C.
Morrison, P.W. Jr.; Haigis, J.R. (Advanced Fuel Research, Inc., East Hartford, Connecticut 06108 (United States))
Low temperature deposition of transparent conducting oxide films: Comparison of different pulsed sputtering and arc plasma methods
Electrochromically switched, gas-reservoir metal hydride devices with Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows André Anders, Jonathan L. Slack, and Thomas J. Richardson Lawrence Berkeley National Laboratory Berkeley, California Abstract Proof-of-principle gas-reservoir MnNiMg electrochromic mirror devices have been investigated. In contrast to conventional electrochromic approaches, hydrogen is stored (at low concentration) in the gas volume between glass panes of the insulated glass units (IGUs). The elimination of a solid state ion storage layer simplifies the layer stack, enhances overall transmission, and reduces cost. The cyclic switching properties were demonstrated and system durability improved with the incorporation a thin Zr barrier layer between the MnNiMg layer
New approaches for the reduction of plasma arc drop in second-generation thermionic converters. Final report
Investigations of ion generation and recombination mechanisms in the cesium plasma as they pertain to the advanced mode thermionic energy converter are described. The changes in plasma density and temperature within the converter have been studied under the influence of several promising auxiliary ionization candidate sources. Three novel approaches of external cesium ion generation have been investigated in some detail, namely vibrationally excited N/sub 2/ as an energy source of ionization of Cs ions in a DC discharge, microwave power as a means of resonant sustenance of the cesium plasma, and ion generation in a pulse N/sub 2/-Cs mixture. The experimental data obtained and discussed show that all three techniques - i.e. the non-LTE high-voltage pulsing, the energy transfer from vibrationally excited diatomic gases, and the external pumping with a microwave power - have considerable promise as schemes in auxiliary ion generation applicable to the advanced thermionic energy converter.
Hatziprokopiou, M.E.; Shaw, D.T.
Verification of the O-Si-N complex in plasma-enhanced chemical vapor deposition silicon oxynitride films
Silicon oxynitride films were deposited using a plasma-enhanced chemical vapor deposition process. The bond configurations of the constituent atoms in the deposited film were analyzed using x-ray photoelectron spectroscopy. Analysis of the Si 2p spectra showed the presence of nonstoichiometric silicon oxide and silicon oxynitride. Analysis of the binding energy shifts induced by Si-O and Si-N bond formation indicated an O-Si-N complex was present in the film matrix. Component balance analysis indicated that second-nearest-neighbor bond interactions were not the cause of these energy shifts and supported the presence of an O-Si-N complex.
Naskar, Sudipto; Wolter, Scott D.; Bower, Christopher A.; Stoner, Brian R.; Glass, Jeffrey T. [Center for Materials and Electronics Technologies, RTI-International, Research Triangle Park, North Carolina 27709 and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States); Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States); Center for Materials and Electronics Technologies, RTI-International, Research Triangle Park, North Carolina 27709 (United States); Center for Materials and Electronics Technologies, RTI-International, Research Triangle Park, North Carolina 27709 and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States); Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)
Transparent conductive indium zinc oxide films prepared by pulsed plasma deposition
Transparent conductive indium zinc oxide films were prepared by pulsed plasma deposition from a ceramic target (90 wt. % In{sub 2}O{sub 3} and 10 wt. % ZnO). The dependences of film properties upon the substrate temperature was investigated using characterization methods including x-ray diffraction, atomic force microscope, Hall measurement, ultraviolet-visible spectroscopy, and x-ray photoelectron spectroscopy. The films grown at room temperature had a rather smooth surface due to the amorphous structure, with a root mean square roughness of less than 1 nm. The atomic ratio of Zn/(Zn + In) in these films is 15.3 at. %, which is close to that in the target, and the chemical states of indium and zinc atoms were In{sup 3+} and Zn{sup 2+}, respectively. The films deposited on a substrate with a temperature of 200 Degree-Sign C exhibited polycrystalline structure and a preferred growth orientation along the (222) plane. Here the electrical properties were improved due to the better crystallinity, with the films exhibiting a minimum resistivity value of 4.2 Multiplication-Sign 10{sup -4}{Omega} cm, a maximum carrier mobility of 45 cm{sup 2} V{sup -1} s{sup -1}, and an optical transmittance over 80% in the visible region.
Wan Runlai; Yang Ming; Zhou Qianfei; Zhang Qun [Department of Materials Science, Fudan University, Shanghai 200433 (China)
Surface modification of nickel battery electrodes by cobalt plasma immersion ion implantation and deposition
Nickel hydroxide is the electrochemically active material in the positive electrode of several important rechargeable alkaline-electrolyte batteries. It is believed that divalent Ni(OH){sub 2} is converted to trivalent NiOOH as the electrode is electrochemically oxidized during the battery charging process, and the reverse reaction (electrochemical reduction) occurs during battery discharge, however the details of this process are not completely understood. Because these electrochemical reactions involve surface charge-transfer processes, it is anticipated that surface modification may result in improved battery performance. We used broad-beam metal ion implantation and Metal Plasma Immersion Ion Implantation and Deposition to add cobalt and other species to the nickel electrode surface. The principle of the latter technique is explained in detail. It is shown that implanted and deposited cobalt ions act as a dopant of Ni(OH){sub 2}, and thereby alter its electronic conductivity. This electronic effect promotes lateral growth of NiOOH nodules and more-complete conversion of Ni(OH){sub 2} to NiOOH, which can be interpreted in terms of the nodule growth model. Other dopants such as Au, W, Pb, Ta and Ti{sub 4}O{sub 7} were also tested for suppressing the parasitic oxygen evolution reaction in rechargeable nickel cells.
Anders, S.; Anders, A.; Brown, I.; Kong, F.; McLarnon, F.
Nitrogen actinometry for measurement of nitrogen radical spatial distribution in large-area plasma-enhanced chemical vapor deposition
Density distributions of radicals in the large-area silicon nitride (Si{sub 3}N{sub 4}) plasma-enhanced chemical vapor deposition (PECVD) process were measured using a spatially resolvable optical emission spectrometer (SROES). To determine the qualitative distribution of a target radical, the authors used optical actinometry with nitrogen (N{sub 2}) gas as an actinometer. To compare the SROES data and process results, the thickness of the deposited Si{sub 3}N{sub 4} thin films using an ellipsometer was measured. By introducing nitrogen-based optical actinometry, the authors obtained very good agreement between the experimental results of the distributions of atomic nitrogen radical and the deposited thicknesses of Si{sub 3}N{sub 4} thin films. Based on these experimental results, the uniformity of the process plasma in the PECVD process at different applied radio frequency powers was analyzed.
Oh, Changhoon; Kang, Minwook; Hahn, Jae W. [Nano Photonics Laboratory, School of Mechanical Engineering, Yonsei University, 50 Yonesi-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Nam, Seungsuk [Based Technology of Equipment Team, LG Display, Paju-City, Gyeonggi-do 413-811 (Korea, Republic of)
Characteristics of indium oxide plasma filters deposited by atmospheric pressure CVD
Thin films of undoped and tin-doped In{sub 2}O{sub 3} are being investigated for use as plasma filters in spectral control applications for thermal photovoltaic cells. These films are required to exhibit high reflectance at wavelengths longer than the plasma wavelength {lambda}{sub p}, high transmittance at wavelengths shorter than {lambda}{sub p} and low absorption throughout the spectrum. Both types of films were grown via atmospheric pressure chemical vapor deposition (APCVD) on Si (100) and fused silica substrates using trimethylindium (TMI), tetraethyltin (TET), and oxygen as the precursors. Fourier Transform InfraRed (FTIR) spectroscopy was used to measure the filter transmittance and reflectance between 1.8--20 {micro}m. Nominal conditions used during the growth of undoped In{sub 2}O{sub 3} were a substrate temperature of 450 C and partial pressures of 1.4 {times} 10{sup {minus}4} atm. and 1 {times} 10{sup {minus}3} atm. for TMI and O{sub 2} respectively. The O{sub 2}/TMI partial pressure ratio and substrate temperature were systematically varied to control the filter characteristics. The plasma wavelength {lambda}{sub p} was found to be a sensitive function of these parameters. Post-growth annealing of the films was done in inert as well as air ambient at elevated temperatures, but was found to have no beneficial effect. Tin-doped In{sub 2}O{sub 3} was grown under similar conditions as above, with a typical TET partial pressure of 4 {times} 10{sup {minus}6} atm. Here also, the material properties and consequently the optical response were found to be strongly dependent on growth conditions such as O{sub 2} and TET partial pressures. Both undoped and tin-doped In{sub 2}O{sub 3} grown on fused silica exhibited enhanced transmittance due to the close matching of refractive indices of In{sub 2}O{sub 3} and silica. X-ray diffractometer measurements indicated that all these films were polycrystalline and highly textured towards the (111) direction. The best undoped and tin-doped In{sub 2}O{sub 3} films had a {lambda}{sub p} around 2.7 {micro}m, peak reflectance greater than 75% and residual absorption below 20%. These results indicate the promise of undoped and tin-doped In{sub 2}O{sub 3} as a material for plasma filters.
Langlois, E.; Murthy, S.D.; Bhat, I.; Gutmann, R. [Rensselaer Polytechnic Inst., Troy, NY (United States); Brown, E.; Dziendziel, R.; Freeman, M.; Choudhury, N. [Lockheed Martin Corp., Schenectady, NY (United States)
Physics of Plasma-Based Ion Implantation&Deposition (PBIID)and High Power Impulse Magnetron Sputtering (HIPIMS): A Comparison
The emerging technology of High Power Impulse MagnetronSputtering (HIPIMS) has much in common with the more establishedtechnology of Plasma Based Ion Implantation&Deposition (PBIID):both use pulsed plasmas, the pulsed sheath periodically evolves andcollapses, the plasma-sheath system interacts with the pulse-drivingpower supply, the plasma parameters are affected by the power dissipated,surface atoms are sputtered and secondary electrons are emitted, etc.Therefore, both fields of science and technology could learn from eachother, which has not been fully explored. On the other hand, there aresignificant differences, too. Most importantly, the operation of HIPIMSheavilyrelies on the presence of a strong magnetic field, confiningelectrons and causing their ExB drift, which is closed for typicalmagnetron configurations. Second, at the high peak power levels used forHIPIMS, 1 kW/cm2 or greater averaged over the target area, the sputteredmaterial greatly affects plasma generation. For PBIID, in contrast,plasma generation and ion processing of the surface (ion implantation,etching, and deposition) are considered rela-tively independentprocesses. Third, secondary electron emission is generally considered anuisance for PBIID, especially at high voltages, whereas it is a criticalingredient to the operation of HIPIMS. Fourth, the voltages in PBIID areoften higher than in HIPIMS. For the first three reasons listed above,modelling of PBIID seems to be easier and could give some guidance forfuture HIPIMS models, which, clearly, will be more involved.
Low voltage arc formation in railguns
A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.
Hawke, R.S.
Hawke, Ronald S. (Livermore, CA)
A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.
Plasma-based ion implantation and deposition: A review of physics, technology, and applications
X. Y. Yao, and K. -M. Yu, "Plasma synthesis of metallic andT. Short, and J. Tendys, "Plasma immersion ion implantationBang, and M. -R. Lin, "Plasma doping for shallow junctions,"
Pelletier, Jacques; Anders, Andre
Plasma and Ion Assistance in Physical Vapor Deposition: A Historical Perspective
Ed. ), Handbook of Plasma Immersion Ion Implantation andK. G. Müller, IEEE Trans. Plasma Sci. [76] I. I. Beilis, R.449. [79] J. Hopwood, Phys. Plasmas 5 (1998) 1624. [80] M.
Microwave plasma assisted supersonic gas jet deposition of thin film materials
An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures.
Schmitt, III, Jerome J. (New Haven, CT); Halpern, Bret L. (Bethany, CT)
Distribution Arc Flash
Arc flash from faults on 480-V circuits is a safety issue that can impact utility work. This report covers results from tests of arc flash and fabric performance from faults in 480-V network protectors and padmounted transformers. It supplements EPRI report 1018694, Distribution Arc Flash: Industry Practices and EPRI report 1018693, Distribution Arc Flash: Analysis Methods and Arc Characteristics.
The effect of hydrogen-plasma and PECVD-nitride deposition on bulk and surface passivation in string-ribbon silicon solar cells
We have investigated whether an in-situ hydrogen or ammonia rf-plasma treatment prior to a PECVD-nitride deposition would promote bulk defect passivation independently of surface effects. We also studied whether the predeposition of a thin silicon-nitride protective layer vbefore performing the plasma treatment would serve to minimize surface damage. We found that for the limited set of deposition conditions in of cells processed using the used five different deposition strategies and compared the resulting cell performance with that investigated so far, the direct deposition of PECVD-nitride produces the best cells on String Ribbon silicon wafers to date, with efficiencies up to 14.5%. Hydrogen and ammonia plasma pretreatments without a protective nitride layer resulted in better bulk passivation, but damaged surfaces. Pretreatments after deposition of the protective layer produced the best surface passivation, but were not effective in passivating the bulk.
Ruby, D.S. [Sandia National Labs., Albuquerque, NM (United States); Wilbanks, W.L.; Fleddermann, C.B. [New Mexico Univ., Albuquerque, NM (United States); Hanoka, J.I. [Evergreen Solar Inc., Waltham, MA (United States)
An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures. 5 figures.
Schmitt, J.J. III; Halpern, B.L.
Defect states in plasma-deposited a-Si:H. Technical progress report, May-July 1979
Three preprints are presented. The first, entitled ''Glow Discharge Optical Spectroscopy Measurement of Dopant Concentrations in a-Si:H,'' reports significant differences between the ratio of boron to silicon of the films and that of their deposition plasmas. The second, entitled ''Growth Morphology and Defects in Plasma-Deposited a-Si:H Films,'' presents structural studies that show that a major class of defect is an anisotropic density fluctuation. Studies of the hydrogen environment suggest that an inhomogeneous hydrogen distribution is associated with these fluctuations. From considerations of the deposition chemistry and nucleation theory, a model is proposed to describe the film growth process and its relationship to defects. The third, entitled ''Luminescence and ESR Studies of Defects in Hydrogenated Amorphous Silicon,'' demonstrates that the two experiments involve identical recombination transitions, and identify two separate processes. One process involves defect states, and from the doping dependence of light induced ESR, it is deduced that the electronically active defects are dangling bonds with positive electronic correlation energy. (LEW)
Knights, J C
High-rate chemical vapor deposition of nanocrystalline silicon carbide films by radio frequency thermal plasma
by liquid spray injection of disilanes into an argonÂhydrogen RF plasma operat- ing at 20Â40 kPa [4]. Here
Zachariah, Michael R.
Weld arc simulator
An arc voltage simulator for an arc welder permits the welder response to a variation in arc voltage to be standardized. The simulator uses a linear potentiometer connected to the electrode to provide a simulated arc voltage at the electrode that changes as a function of electrode position.
Burr, M.J.
Method for minimizing decarburization and other high temperature oxygen reactions in a plasma sprayed material
A method is disclosed for spray coating material which employs a plasma gun that has a cathode, an anode, an arc gas inlet, a first powder injection port, and a second powder injection port. A suitable arc gas is introduced through the arc gas inlet, and ionization of the arc gas between the cathode and the anode forms a plasma. The plasma is directed to emenate from an open-ended chamber defined by the boundary of the anode. A coating is deposited upon a base metal part by suspending a binder powder within a carrier gas that is fed into the plasma through the first powder injection port; a material subject to degradation by high temperature oxygen reactions is suspended within a carrier gas that is fed into the plasma through the second injection port. The material fed through the second injection port experiences a cooler portion of the plasma and has a shorter dwell time within the plasma to minimize high temperature oxygen reactions. The material of the first port and the material of the second port intermingle within the plasma to form a uniform coating having constituent percentages related to the powder-feed rates of the materials through the respective ports.
Lenling, William J. (Madison, WI); Henfling, Joseph A. (Bosque Farms, NM); Smith, Mark F. (Albuquerque, NM)
A typical blade material is made of Nickel super alloy and can bear temperatures up to 950°C. But the operating temperature of a gas turbine is above the melting point of super alloy nearly at 1500°C. This could lead to hot corrosions, high temperature oxidation, creep, thermal fatigue may takes place on the blade material. Though the turbine has an internal cooling system, the cooling is not adequate to reduce the temperature of the blade substrate. Therefore to protect the blade material as well as increase the efficiency of the turbine, thermal barrier coatings (TBCs) must be used. A TBC coating of 250 ?m thick can reduce the temperature by up to 200° C. Air Plasma Spray Process (APS) and High Enthalpy Plasma Spray Process (100HE) were the processes used for coating the blades with the TBCs. Because thermal conductivity increases with increase in temperature, it is desired that these processes yield very low thermal conductivities at high temperatures in order not to damage the blade. An experiment was carried out using Flash line 5000 apparatus to compare the thermal conductivity of both processes.The apparatus could also be used to determine the thermal diffusivity and specific heat of the TBCs. 75 to 2800 K was the temperature range used in the experimentation. It was found out that though 100HE has high deposition efficiency, the thermal conductivity increases with increase in temperatures whiles APS yielded low thermal conductivities.
Uppu, N.; Mensah, P.F.; Ofori, D.
Comparative band alignment of plasma-enhanced atomic layer deposited high-k dielectrics on gallium nitride
Al{sub 2}O{sub 3} films, HfO{sub 2} films, and HfO{sub 2}/Al{sub 2}O{sub 3} stacked structures were deposited on n-type, Ga-face, GaN wafers using plasma-enhanced atomic layer deposition (PEALD). The wafers were first treated with a wet-chemical clean to remove organics and an in-situ combined H{sub 2}/N{sub 2} plasma at 650 Degree-Sign C to remove residual carbon contamination, resulting in a clean, oxygen-terminated surface. This cleaning process produced slightly upward band bending of 0.1 eV. Additional 650 Degree-Sign C annealing after plasma cleaning increased the upward band bending by 0.2 eV. After the initial clean, high-k oxide films were deposited using oxygen PEALD at 140 Degree-Sign C. The valence band and conduction band offsets (VBOs and CBOs) of the Al{sub 2}O{sub 3}/GaN and HfO{sub 2}/GaN structures were deduced from in-situ x-ray and ultraviolet photoemission spectroscopy (XPS and UPS). The valence band offsets were determined to be 1.8 and 1.4 eV, while the deduced conduction band offsets were 1.3 and 1.0 eV, respectively. These values are compared with the theoretical calculations based on the electron affinity model and charge neutrality level model. Moreover, subsequent annealing had little effect on these offsets; however, the GaN band bending did change depending on the annealing and processing. An Al{sub 2}O{sub 3} layer was investigated as an interfacial passivation layer (IPL), which, as results suggest, may lead to improved stability, performance, and reliability of HfO{sub 2}/IPL/GaN structures. The VBOs were {approx}0.1 and 1.3 eV, while the deduced CBOs were 0.6 and 1.1 eV for HfO{sub 2} with respect to Al{sub 2}O{sub 3} and GaN, respectively.
Yang Jialing; Eller, Brianna S.; Zhu Chiyu; England, Chris; Nemanich, Robert J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)
ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition
We report a breakthrough in fabricating ZnO homojunction light-emitting diode by metal organic chemical vapor deposition. Using NO plasma, we are able to grow p-type ZnO thin films on n-type bulk ZnO substrates. The as-grown films on glass substrates show hole concentration of 10{sup 16}-10{sup 17} cm{sup -3} and mobility of 1-10 cm{sup 2} V{sup -1} s{sup -1}. Room-temperature photoluminescence spectra reveal nitrogen-related emissions. A typical ZnO homojunction shows rectifying behavior with a turn-on voltage of about 2.3 V. Electroluminescence at room temperature has been demonstrated with band-to-band emission at I=40 mA and defect-related emissions in the blue-yellow spectrum range.
Xu, W.Z.; Ye, Z.Z.; Zeng, Y.J.; Zhu, L.P.; Zhao, B.H.; Jiang, L.; Lu, J.G.; He, H.P.; Zhang, S.B. [State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)
Dc arc weld starter
A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.
Campiotti, R.H.; Hopwood, J.E.
DC arc weld starter
Campiotti, Richard H. (Tracy, CA); Hopwood, James E. (Oakley, CA)
Study of plasma enhanced chemical vapor deposition of boron-doped hydrogenated amorphous silicon thin films and the application to p-channel thin film transistor
The material and process characteristics of boron doped hydrogenated amorphous silicon (a-Si:H) thin film deposited by plasma enhanced chemical vapor deposition technique (PECVD) have been studied. The goal is to apply the high quality films deposited at low substrate temperature for devices such as thin film transistors (TFTs). The effect of the deposition parameters such as doping gas concentration, substrate temperature, hydrogen dilution, helium dilution, power density, and pressure at 50 kHz rf frequency on the films' characteristics were analyzed. The films' electrical property was characterized by its dark resistivity. The chemical composition and bonding characteristics were discussed. p-channel TFTs were fabricated with these optimized films. Three different levels of dopant concentrations in the channel were used to detect the dopant effect on the TFT properties. Doping resulted in the increase of film deposition rate. The low film deposition rate at the high temperature deposition corresponds to a dense structured film. The increase of gas phase H? concentration could increase H? etching of the weak bonds in the film, which is consistent with the decrease of the deposition rate. Film's dark conductivity is determined by the atomic B concentration in the film, the substrate temperature, the ion bombardment effect, the surface morphology, and the gas phase and film hydrogen concentration. At high power density and high pressure plasma condition, film with a high deposition rate shows a high conductivity. However, excessive ion bombardment effect, e.g. in powdery plasma region, limits the further increase of the conductivity. Film deposited with He dilution demonstrates a higher conductivity compared to the H? dilution counterpart. This might be attributed to a more effective ion bombardment effect of the former. Powder generation in the plasma significantly affects the conductivity of He diluted film compared to the H? diluted ones, which might be due to the less H? etching effect at the He dilution deposition. The output and transfer characteristics show the normal p-channel TFTs behavior. TFT characteristics, such as mobility, threshold voltage, and on-off current ratio were affected by the doping gas concentration in the channel layer and the deposition process.
Nominanda, Helinda
Feature based cost and carbon emission modelling for wire and arc additive manufacturing.
??The wire and arc additive manufacturing (WAAM) is a CNC and welding deposition based additive manufacturing method. This novel manufacturing technique has potential cost and… (more)
Guo, Jianing
Cl atom recombination on silicon oxy-chloride layers deposited on chamber walls in chlorine-oxygen plasmas
Chlorine atom recombination coefficients were measured on silicon oxy-chloride surfaces deposited in a chlorine inductively coupled plasma (ICP) with varying oxygen concentrations, using the spinning wall technique. A small cylinder embedded in the walls of the plasma reactor chamber was rapidly rotated, repetitively exposing its surface to the plasma chamber and a differentially pumped analysis chamber housing a quadruple mass spectrometer for line-of-sight desorbing species detection, or an Auger electron spectrometer for in situ surface analysis. The spinning wall frequency was varied from 800 to 30 000 rpm resulting in a detection time, t (the time a point on the surface takes to rotate from plasma chamber to the position facing the mass or Auger spectrometer), of {approx}1-40 ms. Desorbing Cl{sub 2}, due to Langmuir-Hinshelwood (LH) Cl atom recombination on the reactor wall surfaces, was detected by the mass spectrometer and also by a pressure rise in one of the differentially pumped chambers. LH Cl recombination coefficients were calculated by extrapolating time-resolved desorption decay curves to t = 0. A silicon-covered electrode immersed in the plasma was either powered at 13 MHz, creating a dc bias of -119 V, or allowed to electrically float with no bias power. After long exposure to a Cl{sub 2} ICP without substrate bias, slow etching of the Si wafer coats the chamber and spinning wall surfaces with an Si-chloride layer with a relatively small amount of oxygen (due to a slow erosion of the quartz discharge tube) with a stoichiometry of Si:O:Cl = 1:0.38:0.38. On this low-oxygen-coverage surface, any Cl{sub 2} desorption after LH recombination of Cl was below the detection limit. Adding 5% O{sub 2} to the Cl{sub 2} feed gas stopped etching of the Si wafer (with no rf bias) and increased the oxygen content of the wall deposits, while decreasing the Cl content (Si:O:Cl = 1:1.09:0.08). Cl{sub 2} desorption was detectable for Cl recombination on the spinning wall surface coated with this layer, and a recombination probability of {gamma}{sub Cl} = 0.03 was obtained. After this surface was conditioned with a pure oxygen plasma for {approx}60 min, {gamma}{sub Cl} increased to 0.044 and the surface layer was slightly enriched in oxygen fraction (Si:O:Cl = 1:1.09:0.04). This behavior is attributed to a mechanism whereby Cl LH recombination occurs mainly on chlorinated oxygen sites on the silicon oxy-chloride surface, because of the weak Cl-O bond compared to the Cl-Si bond.
Khare, Rohit; Srivastava, Ashutosh; Donnelly, Vincent M. [Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204 (United States)
AdaptiveARC | Open Energy Information
Open Energy Info (EERE)
AdaptiveARC AdaptiveARC Jump to: navigation, search Name AdaptiveARC Address 7683 Sitio Manana Place Carlsbad, California Zip 92009 Sector Biomass Product Waste-to-clean-energy startup is developing an arc-plasma reactor Website http://www.adaptivearc.com/ Coordinates 33.07959°, -117.22539° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.07959,"lon":-117.22539,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Atomic layer deposition of Al{sub 2}O{sub 3} on GaSb using in situ hydrogen plasma exposure
In this report, we study the effectiveness of hydrogen plasma surface treatments for improving the electrical properties of GaSb/Al{sub 2}O{sub 3} interfaces. Prior to atomic layer deposition of an Al{sub 2}O{sub 3} dielectric, p-GaSb surfaces were exposed to hydrogen plasmas in situ, with varying plasma powers, exposure times, and substrate temperatures. Good electrical interfaces, as indicated by capacitance-voltage measurements, were obtained using higher plasma powers, longer exposure times, and increasing substrate temperatures up to 250 Degree-Sign C. X-ray photoelectron spectroscopy reveals that the most effective treatments result in decreased SbO{sub x}, decreased Sb, and increased GaO{sub x} content at the interface. This in situ hydrogen plasma surface preparation improves the semiconductor/insulator electrical interface without the use of wet chemical pretreatments and is a promising approach for enhancing the performance of Sb-based devices.
Ruppalt, Laura B.; Cleveland, Erin R.; Champlain, James G.; Prokes, Sharka M.; Brad Boos, J.; Park, Doewon; Bennett, Brian R. [Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)
Deposition of Dense SiO2 Thin Films for Electrical Insulation Applications by Microwave ECR Plasma Source Enhanced RF Reactive Magnetron Sputtering
Silicon dioxide thin films have been deposited successfully on high speed steel (HSS) cutting tool substrates by means of microwave electron cyclotron resonance (MW-ECR) plasma source enhanced RF reactive magnetron sputtering of a pure silica target ... Keywords: SiO2 thin films, Electrical insulation properties, RF magnetron sputtering, Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS)
Qiyong Zeng; Xiaofeng Zheng; Zhonghua Yu; Yunxian Cui
Theoretical analysis of ARC constriction
The physics of the thermionic converter is governed by strong electrode-plasma interactions (emissions surface scattering, charge exchange) and weak interactions (diffusion, radiation) at the maximum interelectrode plasma radius. The physical processes are thus mostly convective in thin sheaths in front of the electrodes and mostly diffusive and radiative in the plasma bulk. The physical boundaries are open boundaries to particle transfer (electrons emitted or absorbed by the electrodes, all particles diffusing through some maximum plasma radius) and to convective, conductive and radiative heat transfer. In a first approximation the thermionic converter may be described by a one-dimensional classical transport theory. The two-dimensional effects may be significant as a result of the sheath sensitivity to radial plasma variations and of the strong sheath-plasma coupling. The current-voltage characteristic of the converter is thus the result of an integrated current density over the collector area for which the boundary conditions at each r determine the regime (ignited/unignited) of the local current density. A current redistribution strongly weighted at small radii (arc constriction) limits the converter performance and opens questions on constriction reduction possibilities. The questions addressed are the followng: (1) what are the main contributors to the loss of current at high voltage in the thermionic converter; and (2) is arc constriction observable theoretically and what are the conditions of its occurrence. The resulting theoretical problem is formulated and results are given. The converter electrical current is estimated directly from the electron and ion particle fluxes based on the spatial distribution of the electron/ion density n, temperatures T/sub e/, T/sub i/, electrical voltage V and on the knowledge of the transport coefficients. (WHK)
Stoenescu, M.L.; Brooks, A.W.; Smith, T.M.
Deposition Process
Pulsed Plasma Processing Pulsed Plasma Processing NEW: Downloadable: Invited Talk "Pulsed Metal Plasmas," presented at the 2006 AVS Meeting, San Francisco, California, November 15, 2006. (PDF, file size 8 MB). Plasma Sources for Window Coatings Deposition processes for low-emittance and solar control coatings can be improved through the use of advanced plasma technology developed at LBNL. A new type of constricted glow-discharge plasma source was selected for the 1997 R&D 100 Award. Invented by LBNL researchers Andre Anders, Mike Rubin, and Mike Dickinson, the source was designed to be compatible with industrial vacuum deposition equipment and practice. Construction is simple, rugged and inexpensive. It can operate indefinitely over a wide range of chamber pressure without any consumable parts such as filaments or grids. Several different gases including Argon, Oxygen and Nitrogen have been tested successfully.
Magnetically controlled deposition of metals using gas plasma. Quarterly progress report, October 1994--December 1994
The objective of the grant is to develop a method of spraying materials on a substrate in a controlled manner to eliminate the waste inherent in present plating processes. The process under consideration is magnetically controlled plasma spraying. The project continues to be on schedule. The field equations have been developed and were reported in the April-June 1994 Progress Report. The equations for the external magnetic field were reported in the July-September 1994 progress report. The field equations have been cast in a format that allows solution using Finite Element (FE) techniques. The development of the computer code that will allow evaluation of the proposed technique and design of an experiment to prove the proposed process is underway.
Not Available
Interactions between radical growth precursors on plasma-deposited silicon thin-film surfaces
We present a detailed analysis of the interactions between growth precursors, SiH{sub 3} radicals, on surfaces of silicon thin films. The analysis is based on a synergistic combination of density functional theory calculations on the hydrogen-terminated Si(001)-(2x1) surface and molecular-dynamics (MD) simulations of film growth on surfaces of MD-generated hydrogenated amorphous silicon (a-Si:H) thin films. In particular, the authors find that two interacting growth precursors may either form disilane (Si{sub 2}H{sub 6}) and desorb from the surface, or disproportionate, resulting in the formation of a surface dihydride (adsorbed SiH{sub 2} species) and gas-phase silane (SiH{sub 4}). The reaction barrier for disilane formation is found to be strongly dependent on the local chemical environment on the silicon surface and reduces (or vanishes) if one/both of the interacting precursors is/are in a ''fast diffusing state,'' i.e., attached to fivefold coordinated surface Si atoms. Finally, activation energy barriers in excess of 1 eV are obtained for two chemisorbed (i.e., bonded to a fourfold coordinated surface Si atom) SiH{sub 3} radicals. Activation energy barriers for disproportionation follow the same tendency, though, in most cases, higher barriers are obtained compared to disilane formation reactions starting from the same initial configuration. MD simulations confirm that disilane formation and disproportionation reactions also occur on a-Si:H growth surfaces, preferentially in configurations where at least one of the SiH{sub 3} radicals is in a ''diffusive state.'' Our results are in agreement with experimental observations and results of plasma process simulators showing that the primary source for disilane in low-power plasmas may be the substrate surface.
Bakos, Tamas; Valipa, Mayur S.; Maroudas, Dimitrios [Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003-3110 (United States)
Mechanical Properties of Twin Wire Arc Sprayed Inconel Coating ...
Synthesis and Characterization of Plasma Polymerized Thin Films Deposited from Benzene and Hexamethyldisiloxane Using (PECVD) Method · Synthesis of ...
Onsite Plasma Welding Technology and Equipment Development: RRAC Task 88
Automated plasma transfer arc welding (PTAW) with powder feed capabilities is commonly used for applying hardfacing alloys for new installations and for replacement valves. With a variety of hardfacing and corrosion resistant alloys readily available in the powder form, the PTAW process is an effective and economical process for applying hardfacing materials. The process can obtain high quality deposits with a very low dilution rate and excellent material properties with a minimum number of weld layers. ...
Arc flash from faults on distribution circuits is a safety issue that can impact work practices, protection requirements for line and substation workers, and relay and other overcurrent protection settings and practices. This report describes analysis methods and test results for EPRI-sponsored research on arc flash conducted in 2008.
Use of SiBN and SiBON films prepared by plasma enhanced chemical vapor deposition from borazine as interconnection dielectrics
Thin films of silicon boron nitride (SiBN) of typical composition Si{sub 0.09}B{sub 0.39}N{sub 0.51} and silicon boron oxynitride (SiBON) of typical composition Si{sub 0.16}B{sub 0.29}O{sub 0.41}N{sub 0.14} were prepared by plasma enhanced chemical vapor deposition and the properties of these films were evaluated with respect to their suitability as interconnection dielectrics in microelectronic fabrication. Films were deposited on 125 mm silicon substrates in a parallel-plate reactor at a substrate temperature of 400 C and a plasma power of 0.5 W/cm{sup 2}. Boron nitride, for comparison of electrical properties, was deposited from borazine (B{sub 3}N{sub 3}H{sub 6}); silicon boron nitride was deposited from borazine, disilane (Si{sub 2}H{sub 6}), and ammonia (NH{sub 3}); silicon boron oxynitride was deposited from borazine, disilane, ammonia, and nitrous oxide (N{sub 2}O). Metal-insulator-metal capacitors were fabricated and electrical measurements indicated that all three films had excellent dielectric properties with dielectric constants of 4.1, 4.7, and 3.9 for BN, SiBN, and SiBON, respectively. Tests of conformality indicated that deposition into trenches with an aspect ratio of 4:1 gave conformality greater than 70%. Silicon boron oxynitride was shown to be an excellent barrier to the diffusion of copper. A planar, single level metal-insulator structure was constructed using a SiBN/SiBON insulator with copper metallization.
Kane, W.F.; Cohen, S.A.; Hummel, J.P.; Luther, B. [IBM Research Div., Yorktown Heights, NY (United States). T.J. Watson Research Center; Beach, D.B. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.
Theory of Parabolic Arcs in Interstellar Scintillation Spectra
Our theory relates the secondary spectrum, the 2D power spectrum of the radio dynamic spectrum, to the scattered pulsar image in a thin scattering screen geometry. Recently discovered parabolic arcs in secondary spectra are generic features for media that scatter radiation at angles much larger than the rms scattering angle. Each point in the secondary spectrum maps particular values of differential arrival-time delay and fringe rate (or differential Doppler frequency) between pairs of components in the scattered image. Arcs correspond to a parabolic relation between these quantities through their common dependence on the angle of arrival of scattered components. Arcs appear even without consideration of the dispersive nature of the plasma. Arcs are more prominent in media with negligible inner scale and with shallow wavenumber spectra, such as the Kolmogorov spectrum, and when the scattered image is elongated along the velocity direction. The arc phenomenon can be used, therefore, to constrain the inner scale and the anisotropy of scattering irregularities for directions to nearby pulsars. Arcs are truncated by finite source size and thus provide sub micro arc sec resolution for probing emission regions in pulsars and compact active galactic nuclei. Multiple arcs sometimes seen signify two or more discrete scattering screens along the propagation path, and small arclets oriented oppositely to the main arc persisting for long durations indicate the occurrence of long-term multiple images from the scattering screen.
James M. Cordes; Barney J. Rickett; Daniel R. Stinebring; William A. Coles
Electric arc saw apparatus
A portable, hand held electric arc saw has a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc to erode a workpiece. Electric current is supplied to the blade by biased brushes and a slip ring which are mounted in the frame. A pair of freely movable endless belts in the form of crawler treads stretched between two pulleys are used to facilitate movement of the electric arc saw. The pulleys are formed of dielectric material to electrically insulate the crawler treads from the frame.
Deichelbohrer, Paul R. (Richland, WA)
Welding arc initiator
An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome. 3 figs.
Correy, T.B.
An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome.
Correy, Thomas B. (Richland, WA)
Multi-cathode metal vapor arc ion source
An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam. One embodiment of the appaatus utilizes a multi-cathode arrangement for interaction with the anode.
Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); MacGill, Robert A. (645 Kern St., Richmond, CA 94805)
Filtered cathodic arc source
Disclosed is a continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45{degrees} to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles.
Falabella, S.; Sanders, D.M.
A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge is described. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45[degree] to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles. 3 figures.
A portable, hand-held electric arc saw apparatus comprising a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc between the blade and a workpiece of opposite polarity. Electrically conducting means are provided on said frame for transmitting current to said blade. A pair of freely movable endless belts in the form of crawler treads are employed to facilitate movement of the apparatus relative to the workpiece.
Deichelbohrer, P.R.
Arc flash from faults on distribution circuits is a safety issue that can impact work practices, protection requirements for line and substation workers, and relay and other overcurrent protection settings and practices. Highlights of the research results are the following: Arcs did not sustain in any of the tests at 120/208 V in network protectors or meters. Because of low incident energies, only single-layer flame-retardant clothing is needed. Testing on medium-voltage equipment showed wide variability...
Characterisations Of Al{sub 2}O{sub 3}-13% Wt TiO{sub 2} Deposition On Mild Steel Via Plasma Spray Method
To date, plasma sprayed alumina titania have been widely used as wear resistance coatings in textile, machinery and printing industries. Previous studies showed that the coating microstructures and properties were strongly depended on various parameters such as ceramic composition, grain size powders and spray parameters, thus, influencing the melting degree of the alumina titania during the deposition process. The aim of this study focuses on the evolution of the micron sizes of alumina-13%wt titania at different plasma spray power, ranging from 20kW to 40kW. It was noted that the coating porosity of alumina-13%wt titania were decreased from 6.2% to 4% by increasing the plasma power from 20 to 40 kW. At lower power value, partially melted powders were deposited, generating over 6% porosity within the microstructures. Percentage of porosity about 5.6% gave the best ratio of bi-modal structures, providing the highest microhardness value. Furthermore, the effect of microstructure and porosity formation on wear resistance was also discussed. Coatings with less porosity exhibited better resistance to wear, in which the wear resistance of coated mild steel possessed only {approx}5 x 10{sup -4} cm{sup 3}/Nm with 4% of porosity.
Yusoff, N. H.; Isa, M. C. [Maritime Technology Divison, Science And Technology Research Institute For Defence (STRIDE) c/o KD MALAYA 32100 Pangkalan TLDM, Lumut, Perak (Malaysia); Ghazali, M. J.; Muchtar, A.; Forghani, S. [Dept. of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia); Daud, A. R. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia)
Dual-chamber plasma deposition of A-Si:H solar cells at high rates using disilane
The use of a separated chamber deposition system for the fabrication of a-Si:H solar cells from disilane at high deposition rates results in a substantial improvement in short circuit current compared to that obtained from a single-chamber system. The spectral responses of cells fabricated in the dual-chamber mode are compared to those made in the single-chamber mode. The results are interpreted by assuming that the rate of removal of boron contaminants from the chamber is independent of deposition rate.
Rajeswaran, G.; Vanier, P.E.; Corderman, R.R.; Kampas, F.J.
Soft arc consistency revisited
The Valued Constraint Satisfaction Problem (VCSP) is a generic optimization problem defined by a network of local cost functions defined over discrete variables. It has applications in Artificial Intelligence, Operations Research, Bioinformatics and ... Keywords: Constraint optimization, Graphical model, Local consistency, Soft arc consistency, Soft constraints, Submodularity, Valued constraint satisfaction problem, Weighted constraint satisfaction problem
M. C. Cooper; S. de Givry; M. Sanchez; T. Schiex; M. Zytnicki; T. Werner
Generation of hydrogen-rich gas using non equilibrium plasma discharges.
??This dissertation investigates Non equilibrium plasma discharges, particularly gliding arc plasma discharge and dielectric barrier discharge (DBD) as alternative techniques to thermal or catalytic conversion… (more)
Odeyemi, Olufela O.
Hall-effect arc protector
The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored. 2 figs.
Rankin, R.A.; Kotter, D.K.
The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored.
Rankin, Richard A. (Ammon, ID); Kotter, Dale K. (Shelley, ID)
A Miocene Island-Arc Volcanic Seamount- The Takashibiyama Formation,
Island-Arc Volcanic Seamount- The Takashibiyama Formation, Island-Arc Volcanic Seamount- The Takashibiyama Formation, Shimane Peninsula, Sw Japan Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Miocene Island-Arc Volcanic Seamount- The Takashibiyama Formation, Shimane Peninsula, Sw Japan Details Activities (0) Areas (0) Regions (0) Abstract: The Miocene volcanic complex of the Takashibiyama Formation consists largely of subalkali, subaqueous basalt to andesite lavas and andesite to dacite subaqueous volcaniclastic flow deposits. Most of subaqueous lavas are moderately to intensely brecciated with rugged rough surfaces and ramp structures similar to subaerial block lava. Volcaniclastic flow deposits commonly include basalt to andesite lava fragments and/or pyroclastic materials, and are similar in internal
Use of Optical Microscopy to Examine Crystallite Nucleation and Growth in Thermally Annealed Plasma Enhanced Chemical Vapor Deposition and Hot Wire Chemical Vapor Deposition a-Si:H Films
We report a simple method to investigate crystallite nucleation and growth in stepwise, thermally annealed plasma enhanced chemical vapor deposition and hot wire chemical vapor deposition a-Si:H films. By confining film thicknesses to the range 500-4000 {angstrom}, optical microscopy in the reflection mode can be used to readily detect crystallites in the thermally annealed a-Si:H lattice. Measurements of the crystallite density versus annealing time for identically prepared films of different thickness show that the crystallite nucleation rate is smaller for thinner films, suggesting that crystallite nucleation is homogeneous, in agreement with previous results. A comparison of film nucleation rates with those obtained by other methods on identically prepared films shows excellent agreement, thus establishing the validity of the current technique. The potential effect of impurity (oxygen) incorporation during the stepwise annealing in air is shown not to affect crystallite nucleation and growth, in that SIMS oxygen profiles for stepwise versus continuous annealing show not only similar impurity profiles but also similar bulk impurity densities.
Mahan, A. H.; Dabney, M. S.; Reedy, Jr R. C.; Molina, D.; Ginley, D. S.
Electrochemical Evaluation of Pyrite Films Prepared by Plasma Spraying
Thermally activated batteries use electrodes that are typically fabricated by cold pressing of powder. In the LiSi/FeS2 system, natural (mineral) pyrite is used for the cathode. In an effort to increase the energy density and specific energy of these batteries, flame and plasma spraying to form thin films of pyrite cathodes were evaluated. The films were deposited on a 304 stainless steel substrate (current collector) and were characterized by scanning electron microscopy and x-ray dlfllaction. The films were electrochemically tested in single cells at 5000C and the petiormance compared to that of standard cells made with cold-pressed powders. The best results were obtained with material deposited by de-arc plasma spraying with a proprietq additive to suppress thermal decomposion of the pyrite.
Guidotti, R.A.; Reinhardt, F.W.
Controlled zone microwave plasma system
An apparatus and method for initiating a process gas plasma. A conductive plate having a plurality of conductive fingers is positioned in a microwave applicator. An arc forms between the conductive fingers to initiate the formation of a plasma. A transport mechanism may convey process materials through the plasma. A spray port may be provided to expel processed materials.
Ripley, Edward B. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Morrell, Jonathan S. (Knoxville, TN)
VIDEO: Vacuum Arc Remelting - TMS
Apr 27, 2007 ... Video excerpts from Superalloys: Melting and Conversion showing the vacuum arc remelting process. SOURCE: TMS. Last Update: February ...
An apparatus is described in which a welding arc created between an annular electrode and a workpiece moves under the influence of an electromagnetic field about the electrode in a closed or annular path. This mode of welding is specially suited to the enclosing of nuclear-fuel slugs in a protective casing. For example, a uranium slug is placed in an aluminum can, and an aluminum closure is welded to the open end of the can along a closed or annular path conforming to the periphery of the end closure.
Lingafelter, J.W.
Electric arc welding gun
This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.
Luttrell, Edward (Clinton, TN); Turner, Paul W. (Idaho Falls, ID)
Gallium composition dependence of crystallographic and thermoelectric properties in polycrystalline type-I Ba{sub 8}Ga{sub x}Si{sub 46-x} (nominal x=14-18) clathrates prepared by combining arc melting and spark plasma sintering methods
The gallium composition dependence of crystallographic and thermoelectric properties in polycrystalline n-type Ba{sub 8}Ga{sub x}Si{sub 46-x} (nominal x=14-18) compounds with the type-I clathrate structure is presented. Samples were prepared by combining arc melting and spark plasma sintering methods. Powder x-ray diffraction, Rietveld analysis, scanning electron microscopy, and energy-dispersive x-ray spectroscopy show that the solubility limit of gallium in the type-I clathrate phase is close to x=15, which is slightly higher than that for a single crystal. The carrier concentration at room temperature decreases from 2 Multiplication-Sign 10{sup 21} cm{sup -3} to 4 Multiplication-Sign 10{sup 20} cm{sup -3} as the Ga content x increases. The Seebeck coefficient, the electrical conductivity, and the thermal conductivity vary systematically with the carrier concentration when the Ga content x varies. The effective mass (2.0m{sub 0}), the carrier mobility (10 cm{sup 2} V{sup -1} s{sup -1}), and the lattice thermal conductivity (1.1 W m{sup -1} K{sup -1}) are determined for the Ga content x=14.51. The dimensionless thermoelectric figure of merit ZT is about 0.55 at 900 K for the Ga content x=14.51. The calculation of ZT using the experimentally determined material parameters predicts ZT=0.8 (900 K) at the optimum carrier concentration of about 2 Multiplication-Sign 10{sup 20} cm{sup -3}. - Graphical abstract: The gallium composition dependence of crystallographic and thermoelectric properties is presented on polycrystalline n-type Ba{sub 8}Ga{sub x}Si{sub 46-x} with the type-I clathrate structure prepared by combining arc melting and spark plasma sintering methods. The thermoelectric figure of merit ZT reaches 0.55 at 900 K due to the increase in the Ga content (close to x=15), and a calculation predicts further improvement of ZT at the optimized carrier concentration. Highlights: Black-Right-Pointing-Pointer Crystallographic properties of Ba{sub 8}Ga{sub x}Si{sub 46-x} clathrates are characterized. Black-Right-Pointing-Pointer Arc melting and spark plasma sintering process enables increase of Ga content. Black-Right-Pointing-Pointer We elucidate the Ga composition dependence of thermoelectric properties. Black-Right-Pointing-Pointer Thermoelectric figure of merit ZT is improved due to the increased Ga content. Black-Right-Pointing-Pointer Calculation predicts a potential ZT=0.8 at 900 K at optimized carrier concentration.
Anno, Hiroaki, E-mail: firstname.lastname@example.com [Department of Electrical Engineering, Faculty of Engineering, Tokyo University of Science, Yamaguchi, 1-1-1 Daigaku-Dori, Sanyoonoda 756-0884 (Japan) [Department of Electrical Engineering, Faculty of Engineering, Tokyo University of Science, Yamaguchi, 1-1-1 Daigaku-Dori, Sanyoonoda 756-0884 (Japan); JST, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Yamada, Hiroki; Nakabayashi, Takahiro; Hokazono, Masahiro [Department of Electrical Engineering, Faculty of Engineering, Tokyo University of Science, Yamaguchi, 1-1-1 Daigaku-Dori, Sanyoonoda 756-0884 (Japan)] [Department of Electrical Engineering, Faculty of Engineering, Tokyo University of Science, Yamaguchi, 1-1-1 Daigaku-Dori, Sanyoonoda 756-0884 (Japan); Shirataki, Ritsuko [Department of Electrical Engineering, Faculty of Engineering, Tokyo University of Science, Yamaguchi, 1-1-1 Daigaku-Dori, Sanyoonoda 756-0884 (Japan) [Department of Electrical Engineering, Faculty of Engineering, Tokyo University of Science, Yamaguchi, 1-1-1 Daigaku-Dori, Sanyoonoda 756-0884 (Japan); JST, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan)
Mirror plasma apparatus
A mirror plasma apparatus which utilizes shielding by arc discharge to form a blanket plasma and lithium walls to reduce neutron damage to the wall of the apparatus. An embodiment involves a rotating liquid lithium blanket for a tandem mirror plasma apparatus wherein the first wall of the central mirror cell is made of liquid lithium which is spun with angular velocity great enough to keep the liquid lithium against the first material wall, a blanket plasma preventing the lithium vapor from contaminating the plasma.
Moir, Ralph W. (Livermore, CA)
Arc fault detection system
An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.
Jha, Kamal N. (Bethel Park, PA)
An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.
Jha, K.N.
Plasma torch with liquid metal electrodes
In order to eliminate the negative effect of erosion processes on electrodes in arc plasma generators, a new scheme of arc discharge was proposed in which the surface of a molten metal acts as electrodes. A plasma reactor was designed on the basis of this concept. The electrophysical characteristics of such a discharge in steam and air as plasma gases were studied. Experiments on destruction of toxic polychlorinated biphenyls and steam coal gasification were performed.
Predtechenskii, M.R.; Tukhto, O.M. [Russian Academy of Science, Novosibirsk (Russian Federation)
Percussive arc welding apparatus
A percussive arc welding apparatus includes a generally cylindrical actuator body having front and rear end portions and defining an internal recess. The front end of the body includes an opening. A solenoid assembly is provided in the rear end portion in the internal recess of the body, and an actuator shaft assembly is provided in the front end portion in the internal recess of the actuator body. The actuator shaft assembly includes a generally cylindrical actuator block having first and second end portions, and an actuator shaft having a front end extending through the opening in the actuator body, and the rear end connected to the first end portion of the actuator block. The second end portion of the actuator block is in operational engagement with the solenoid shaft by a non-rigid connection to reduce the adverse rebound effects of the actuator shaft. A generally transversely extending pin is rigidly secured to the rear end of the shaft. One end of the pin is received in a slot in the nose housing sleeve to prevent rotation of the actuator shaft during operation of the apparatus.
Hollar, Jr., Donald L. (Overland Park, KS)
Texture of atomic layer deposited ruthenium
Ruthenium films were grown by plasma enhanced atomic layer deposition (ALD) on Si(100) and ALD TiN. X-ray diffraction (XRD) showed that the as-deposited films on Si(100) were polycrystalline, on TiN they were (002) oriented. After annealing at 800^oC ... Keywords: Ammonia plasma, Atomic layer deposition, Ruthenium, Silicide, Texture
J. Musschoot; Q. Xie; D. Deduytsche; K. De Keyser; D. Longrie; J. Haemers; S. Van den Berghe; R. L. Van Meirhaeghe; J. D'Haen; C. Detavernier
Hollow Plasma in a Solenoid
A ring cathode for a pulsed, high-current, multi-spot cathodic arc discharge was placed inside a pulsed magnetic solenoid. Photography is used to evaluate the plasma distribution. The plasma appears hollow for cathode positions close the center of the solenoid, and it is guided closer to the axis when the cathode is away from the center.
Anders, Andre; Kauffeldt, Marina; Oks, Efim M.; Roy, Prabir K.
Populations of metastable and resonant argon atoms in radio frequency magnetron plasmas used for deposition of indium-zinc-oxide films
This work reports optical absorption spectroscopy measurements of the number density of Ar atoms in resonant ({sup 3}P{sub 1}, {sup 1}P{sub 1}) and metastable ({sup 3}P{sub 2}, {sup 3}P{sub 0}) states in rf magnetron sputtering plasmas used for the deposition of ZnO-based thin films. While the density of Ar {sup 3}P{sub 2} and {sup 3}P{sub 0} was fairly independent of pressure in the range of experimental conditions investigated, the density of Ar {sup 3}P{sub 1} and {sup 1}P{sub 1} first sharply increased with pressure and then reached a plateau at values close to those of the {sup 3}P{sub 2} and {sup 3}P{sub 0} levels at pressures above about 50 mTorr. At such pressures, ultraviolet radiation from resonant states becomes trapped such that these levels behave as metastable states. For a self-bias voltage of -115 V and pressures in the 5-100 mTorr range, similar number densities of Ar resonant and metastable atoms were obtained for Zn, ZnO, and In{sub 2}O{sub 3} targets, suggesting that, over the range of experimental conditions investigated, collisions between these excited species and sputtered Zn, In, and O atoms played only a minor role on the discharge kinetics. The metastable-to-ground state number density ratios were also fitted to the predictions of a global model using the average electron temperature, T{sub e}, as the only adjustable parameter. For all targets examined, the values of T{sub e} deduced from this method were in excellent agreement with those obtained from Langmuir probe measurements.
Maaloul, L.; Morel, S.; Stafford, L. [Departement de Physique, Universite de Montreal, Montreal, Quebec, H3C 3J7 (Canada)
Formation of Self-Organized Anode Patterns in Arc Discharge Simulations
Pattern formation and self-organization are phenomena commonly observed experimentally in diverse types of plasma systems, including atmospheric-pressure electric arc discharges. However, numerical simulations reproducing anode pattern formation in arc discharges have proven exceedingly elusive. Time-dependent three-dimensional thermodynamic nonequilibrium simulations reveal the spontaneous formation of self-organized patterns of anode attachment spots in the free-burning arc, a canonical thermal plasma flow established by a constant DC current between an axi-symmetric electrodes configuration in the absence of external forcing. The number of spots, their size, and distribution within the pattern depend on the applied total current and on the resolution of the spatial discretization, whereas the main properties of the plasma flow, such as maximum temperatures, velocity, and voltage drop, depend only on the former. The sensibility of the solution to the spatial discretization stresses the computational requirements for comprehensive arc discharge simulations. The obtained anode patterns qualitatively agree with experimental observations and confirm that the spots originate at the fringes of the arc - anode attachment. The results imply that heavy-species - electron energy equilibration, in addition to thermal instability, has a dominant role in the formation of anode spots in arc discharges.
Juan Pablo Trelles
Planar controlled zone microwave plasma system
Ripley, Edward B. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Morrell, Jonathan S. (Knoxvlle, TN)
Charge trapping characteristics of Au nanocrystals embedded in remote plasma atomic layer-deposited Al{sub 2}O{sub 3} film as the tunnel and blocking oxides for nonvolatile memory applications
Remote plasma atomic layer deposited (RPALD) Al{sub 2}O{sub 3} films were investigated to apply as tunnel and blocking layers in the metal-oxide-semiconductor capacitor memory utilizing Au nanocrystals (NCs) for nonvolatile memory applications. The interface stability of an Al{sub 2}O{sub 3} film deposited by RPALD was studied to observe the effects of remote plasma on the interface. The interface formed during RPALD process has high oxidation states such as Si{sup +3} and Si{sup +4}, indicating that RPALD process can grow more stable interface which has a small amount of fixed oxide trap charge. The significant memory characteristics were also observed in this memory device through the electrical measurement. The memory device exhibited a relatively large memory window of 5.6 V under a 10/-10 V program/erase voltage and also showed the relatively fast programming/erasing speed and a competitive retention characteristic after 10{sup 4} s. These results indicate that Al{sub 2}O{sub 3} films deposited via RPALD can be applied as the tunnel and blocking oxides for next-generation flash memory devices.
Lee, Jaesang; Kim, Hyungchul; Park, Taeyong; Ko, Youngbin; Ryu, Jaehun; Jeon, Heeyoung; Park, Jingyu; Jeon, Hyeongtag [Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Division of Materials Science and Engineering, Hanyang University, Seoul 133-791, Korea and R and D Division, Hynix Semiconductor, Inc., Icheon, Gyeonggi-do 467-701 (Korea, Republic of); Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Division of Materials Science and Engineering, Hanyang University, Seoul 133-791, Korea and R and D Division, Hynix Semiconductor, Inc., Icheon, Gyeonggi-do 467-701 (Korea, Republic of); Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791, Korea and Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)
Carbon Co-Deposition Studies in DIII-D L- and H-Mode Plasmas and Implications to the ITER Tritium Inventory
Bull. Am. Phys. Soc. 50, 27 (2005)47th American Physical Society Annual Meeting of Division of Plasma Physics Denver Colorado, US, 2005999612245
McLean, A.G.
Lubricants in Deposition and Machining of Wire and Arc Additive ...
About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Advanced Materials, Processes and Applications for Additive Manufacturing.
Filtered cathodic arc deposition with ion-species-selective bias
obtain a certain electrical resistivity of the growing film,and electrical properties, specially the resistivity, while
Anders, Andre; Pasaja, Nitisak; Sansongsiri, Sakon; Lim, Sunnie H.N.
Improved blue response and efficiency of A-Si:H solar cells deposited from disilane using a dual-chamber plasma system
Thin film amorphous silicon solar cells with glass/SnO/sub 2//p/i/n/Al structures and 6 to 7% AM1 conversion efficiencies were fabricated at rapid deposition rates in a newly constructed dual-chamber glow discharge deposition system. The 500 nm thick intrinsic layer was deposited at the rate of 1.7 nm/s using disilane (Si/sub 2/H/sub 6/)-helium mixtures. This deposition rate is an order of magnitude greater than conventional high efficiency amorphous silicon solar cell depositions. Residual boron doping effects at the p/i interface can severely degrade cell performance particularly when the intrinsic layer is deposited in one chamber of the dual-chamber system and the intrinsic layer is deposited in the other chamber that is free of boron contaminants. Parameters such as electrode spacing, Si/sub 2/H/sub 6/ partial pressure and flow rate were optimized to produce uniform deposition over large areas. At the substrate temperature T/sub s/ selected for solar cell intrinsic layer deposition, the spin density was measured to be a minimum at 5 x 10/sup 15//cm/sup 3/. For a given T/sub s/, an intrinsic layer deposited from Si/sub 2/H/sub 6/ absorbs fewer photons and can generate less current under solar simulation than a similar film produced from monosilane. Identical solar cells were deposited in either the single-chamber mode or the dual-chamber mode for comparison. Single-chamber mode cells perform poorly over the visible wavelengths and hence produce low short circuit currents. The dual-chamber mode cells show a significant improvement in blue response and a factor of two increase in short circuit current over the single-chamber mode cells. Under short circuit conditions, 15 mA/cm/sup 2/ was generated from rapidly deposited (1.7 nm/s) cells from disilane and 18 mA/cm/sup 2/ from low deposition rate (0.18 nm/s) monosilane cells. These values are comparable to or better than those reported for similar cells by other groups.
Schlieren technique applied to the arc temperature measurement in a high energy density cutting torch
Plasma temperature and radial density profiles of the plasma species in a high energy density cutting arc have been obtained by using a quantitative schlieren technique. A Z-type two-mirror schlieren system was used in this research. Due to its great sensibility such technique allows measuring plasma composition and temperature from the arc axis to the surrounding medium by processing the gray-level contrast values of digital schlieren images recorded at the observation plane for a given position of a transverse knife located at the exit focal plane of the system. The technique has provided a good visualization of the plasma flow emerging from the nozzle and its interactions with the surrounding medium and the anode. The obtained temperature values are in good agreement with those values previously obtained by the authors on the same torch using Langmuir probes.
Prevosto, L.; Mancinelli, B. [Departamento Ing. Electromecanica, Grupo de Descargas Electricas, Universidad Tecnologica Nacional, Regional Venado Tuerto, Las Heras 644, Venado Tuerto, Santa Fe 2600 (Argentina); Artana, G. [Departamento Ing. Mecanica, Laboratorio de Fluidodinamica, Facultad de Ingenieria (UBA), Paseo Colon 850 (C1063ACV), Buenos Aires (Argentina); Kelly, H. [Departamento de Fisica, Instituto de Fisica del Plasma (CONICET), Facultad de Ciencias Exactas y Naturales (UBA), Ciudad Universitaria Pab. I, Buenos Aires 1428 (Argentina)
Manual Plasma Welding (PTAW) Evaluation with Powder Hardfacing Alloys
Repair practices for hardfacing alloys using gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) have been evaluated in the past on hardfacing applied with various automated welding processes. Accessibility often limits the use of these welding processes in manual repair applications. Recent developments in plasma transfer arc welding (PTAW) powder welding systems have prompted evaluations of manual repair practices for hardfacing materials. The PTAW powder welding process feeds the fil...
Plasma spraying method for forming diamond and diamond-like coatings
A method and composition is disclosed for the deposition of a thick layer of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition including at least glassy carbon is heated in a direct current plasma arc device to a selected temperature above the softening point, in an inert atmosphere, and is propelled to quickly quenched on a selected substrate. The softened or molten composition crystallizes on the substrate to form a thick deposition layer comprising at least a diamond or diamond-like material. The selected composition includes at least glassy carbon as a primary constituent and may include at least one secondary constituent. Preferably, the secondary constituents are selected from the group consisting of at least diamond powder, boron carbide (B{sub 4}C) powder and mixtures thereof. 9 figs.
Holcombe, C.E.; Seals, R.D.; Price, R.E.
A method and composition for the deposition of a thick layer (10) of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition (12) including at least glassy carbon is heated in a direct current plasma arc device to a selected temperature above the softening point, in an inert atmosphere, and is propelled to quickly quenched on a selected substrate (20). The softened or molten composition (18) crystallizes on the substrate (20) to form a thick deposition layer (10) comprising at least a diamond or diamond-like material. The selected composition (12) includes at least glassy carbon as a primary constituent (14) and may include at least one secondary constituent (16). Preferably, the secondary constituents (16) are selected from the group consisting of at least diamond powder, boron carbide (B.sub.4 C) powder and mixtures thereof.
Holcombe, Cressie E. (Farragut, TN); Seals, Roland D. (Oak Ridge, TN); Price, R. Eugene (Knoxville, TN)
Prototype arc saw design and cutting trials
A program was initiated to develop the arc saw as a tool capable of removing the end fittings from spent nuclear fuel bundles. A special arc saw for this purpose was designed, installed at the Pacific Northwest Laboratory and satisfactorily operated to remove end fittings from simulated, nonradioactive fuel bundles. The design of the arc saw included consideration of the cutting environment, power supply size, control equipment, and work piece size. Several simulated fuel bundles were cut to demonstrate that the arc saw met design specifications. Although the arc saw development program was curtailed before significant performance data could be collected, tests indicate that the arc saw is a good means of cropping spent fuel bundles and is well suited to remote operation and maintenance.
Allison, G.S.
The structure, properties and performance of plasma-sprayed beryllium for fusion applications
Plasma-spray technology is under investigation as a method for producing high thermal conductivity beryllium coatings for use in magnetic fusion applications. Recent investigations have focused on optimizing the plasma-spray process for depositing beryllium coatings on damaged beryllium surfaces. Of particular interest has been optimizing the processing parameters to maximize the through-thickness thermal conductivity of the beryllium coatings. Experimental results will be reported on the use of secondary H{sub 2} gas additions to improve the melting of the beryllium powder and transferred-arc cleaning to improve the bonding between the beryllium coatings and the underlying surface. Information will also be presented on thermal fatigue tests which were done on beryllium coated ISX-B beryllium limiter tiles using 10 sec cycle times with 60 sec cooldowns and an International Thermonuclear Experimental Reactor (ITER) relevant divertor heat flux slightly in excess of 5 MW/m{sup 2}.
Castro, R.G.; Stanek, P.W.; Elliott, K.E. [and others
Method for generating surface plasma
A method for generating a discharge plasma which covers a surface of a body in a gas at pressures from 0.01 Torr to atmospheric pressure, by applying a radio frequency power with frequencies between approximately 1 MHz and 10 GHz across a plurality of paired insulated conductors on the surface. At these frequencies, an arc-less, non-filamentary plasma can be generated to affect the drag characteristics of vehicles moving through the gas. The plasma can also be used as a source in plasma reactors for chemical reaction operations.
Miller, Paul A. (Albuquerque, NM); Aragon, Ben P. (Albuquerque, NM)
Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.
Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.
Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay
Plasma biasing to control the growth conditions of diamond-likecarbon
It is well known that the structure and properties ofdiamond-like carbon, and in particular the sp3/sp2 ratio, can becontrolled by the energy of the condensing carbon ions or atoms. In manypractical cases, the energy of ions arriving at the surface of thegrowing film is determined by the bias applied to the substrate. The biascauses a sheath to form between substrate and plasma in which thepotential difference between plasma potential and surface potentialdrops. In this contribution, we demonstrate that the same results can beobtained with grounded substrates by shifting the plasma potential. This"plasma biasing" (as opposed to "substrate biasing") is shown to workwell with pulsed cathodic carbon arcs, resulting in tetrahedral amorphouscarbon (ta-C) films that are comparable to the films obtained with theconventional substrate bias. To verify the plasma bias approach, ta-Cfilms were deposited by both conventional and plasma bias andcharacterized by transmission electron microscopy (TEM) and electronenergy loss spectrometry (EELS). Detailed data for comparison of thesefilms are provided.
Anders, Andre; Pasaja, Nitisak; Lim, Sunnie H.N.; Petersen, TimC.; Keast, Vicki J.
Acceleration of ordering transformation of a new Fe{sub 2}(Mn,Cr)Si Heusler-alloy film by very high frequency plasma irradiation process during radio frequency sputter deposition
A new Heusler alloy, Fe{sub 2}(Mn,Cr)Si, that is likely to have high spin polarization (P) and high damping constant ({alpha}) was proposed to obtain high magneto-resistance ratio and low spin torque noise in a magnetic read head with a current-perpendicular-to-plane (CPP) giant magneto-resistance (GMR) multilayer. A very high frequency (VHF) plasma irradiation process during radio frequency (RF) sputter deposition was investigated to form the highly ordered structure of the Heusler alloy film with low thermal treatment temperature. The main results are as follows: (1) P and magnetic moment of Fe{sub 2}(Mn{sub 0.5}Cr{sub 0.5})Si with an L2{sub 1} structure were estimated at 0.99 and 2.49 {mu}{sub B}/f.u., respectively, and {alpha} was also estimated to be larger compared with the case of Co{sub 2}MnSi, according to density of states (DOS) calculations. (2) The ordering (at least B2 structure) temperature of Fe{sub 2}(Mn{sub 0.6}Cr{sub 0.4})Si film decreased from 500 to 300 deg. C by using the VHF plasma irradiation process with optimized condition. (3) The surface roughness of Fe{sub 2}(Mn{sub 0.6}Cr{sub 0.4})Si film also reduced from 1.7 to 0.5 nm by using the VHF plasma irradiation process. It is found that the Fe{sub 2}(Mn,Cr)Si Heusler alloy and the VHF plasma irradiation process with optimized condition seems to be applicable for fabrication of high-performance magnetic read head with CPP-GMR device.
Yoshimura, S.; Kobayashi, H.; Egawa, G.; Saito, H. [Center for Geo-environmental Science, Graduate School of Engineering and Resource Science, Akita University, Akita, 010-8502 (Japan); Ishida, S. [Department of Physics, Graduate School of Science and Engineering, Kagoshima University, Kagoshima, 890-8580 (Japan)
Super-radiance in the sodium resonance lines from sodium iodide arc lamps
Super-radiance observed within the centers of the sodium resonance D lines emitted by arc lamps containing sodium iodide as additive in a high-pressure mercury plasma environment was studied by high-resolution emission spectroscopy. The spectral radiance of these self-reversed lines including super-radiance was simulated by considering a local enhancement of the source function due to the presence of an additional source of radiation near the arc wall. Causes of this hitherto unrecognized source of radiation are given.
Karabourniotis, D. [Department of Physics, Institute of Plasma Physics, University of Crete, 71003 Heraklion (Greece); Drakakis, E. [Department of Electrical Engineering, Technological Educational Institute, Heraklion (Greece)
Fundamental studies of defect generation in amorphous silicon alloys grown by remote plasma-enhanced chemical-vapor deposition (Remote PECVD)
We demonstrated that the remote PECVD process can be used to deposit heavily doped n-type and p-type a-Si:H thin films. We optimized conditions for depositing undoped, near-intrinsic and heavily doped thin films of [mu]c(microcrystalline)-Si by remote PECVD. We extended the remote PECVD process to the deposition of undoped and doped a-Si,C:H and [mu]c-Si,C alloy films. We analyzed transport data for the dark conductivity in undoped and doped a-Si:H, a-Si,C:H, [mu]c-Si and [mu]c-Si,C films. We studied the properties of doped a-Si:H and [mu]c-Si in MOS capacitors using [approximately]10 [Omega]-cm p-type crystalline substrates and thermally grown Si0[sub 2] dielectric layers. We collaborated with a group at RWTH in Aachen, Germany, and studied the contributions of process induced defect states to the recombination of photogenerated electron pairs. We applied a tight-binding model to Si-Bethe lattice structures to investigate the effects of bond angle, and dihedral angle disorder. We used ab initio and empirical calculations to study non-random bonding arrangements in a-Si,O:H and doped a-Si:H films.
Lucovsky, G.; Nemanich, R.J.; Bernholc, J.; Whitten, J.; Wang, C.; Davidson, B.; Williams, M.; Lee, D.; Bjorkman, C.; Jing, Z. (North Carolina State Univ., Raleigh, NC (United States))
Plasma technology directory
The Plasma Technology Directory has two main goals: (1) promote, coordinate, and share plasma technology experience and equipment within the Department of Energy; and (2) facilitate technology transfer to the commercial sector where appropriate. Personnel are averaged first by Laboratory and next by technology area. The technology areas are accelerators, cleaning and etching deposition, diagnostics, and modeling.
Ward, P.P.; Dybwad, G.L.
Plasma jet ignition device
An ignition device of the plasma jet type is disclosed. The device has a cylindrical cavity formed in insulating material with an electrode at one end. The other end of the cylindrical cavity is closed by a metal plate with a small orifice in the center which plate serves as a second electrode. An arc jumping between the first electrode and the orifice plate causes the formation of a highly-ionized plasma in the cavity which is ejected through the orifice into the engine cylinder area to ignite the main fuel mixture. Two improvements are disclosed to enhance the operation of the device and the length of the plasma plume. One improvement is a metal hydride ring which is inserted in the cavity next to the first electrode. During operation, the high temperature in the cavity and the highly excited nature of the plasma breaks down the metal hydride, liberating hydrogen which acts as an additional fuel to help plasma formation. A second improvement consists of a cavity insert containing a plurality of spaced, metal rings. The rings act as secondary spark gap electrodes reducing the voltage needed to maintain the initial arc in the cavity.
McIlwain, Michael E. (Franklin, MA); Grant, Jonathan F. (Wayland, MA); Golenko, Zsolt (North Reading, MA); Wittstein, Alan D. (Fairfield, CT)
Synthesis and Characterization of Plasma Polymerized Thin Films ...
Presentation Title, Synthesis and Characterization of Plasma Polymerized Thin Films Deposited from Benzene and Hexamethyldisiloxane Using (PECVD) ...
An arc fault detection system
An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn, opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.
Jha, Kamal N.
Numerical predictions of railgun performance including the effects of ablation and arc drag
Thermal radiation from plasma armatures in railguns may cause vaporization and partial ionization of the rail and insulator materials. This causes an increase in mass of the arc, which has an adverse effect on projectile velocity. Viscous drag on the arc also has a deleterious effect, particularly at high velocities. These loss mechanisms are modeled in the Los Alamos Railgun Estimator code. Simulations were performed and numerical results were compared with experimental data for a wide range of tests performed at the Los Alamos and Lawrence Livermore National Laboratories, the Ling Temco Vought Aerospace and Defense Company, and the Center for Electromechanics at the University of Texas at Austin. The effects of ablation and arc drag on railgun performance are discussed. Parametric studies illustrate the effects of some design parameters on projectile velocity and launcher efficiency. Some strategies for reducing the effects of ablation are proposed.
Schnurr, N.M.; Kerrisk, J.F.; Parker, J.V.
Plasma source ion implantation research and applications at Los Alamos National Laboratory
Plasma Source Ion Implantation research at Los Alamos Laboratory includes direct investigation of the plasma and materials science involved in target surface modification, numerical simulations of the implantation process, and supporting hardware engineering. Target materials of Al, Cr, Cu-Zn, Mg, Ni, Si, Ti, W, and various Fe alloys have been processed using plasmas produced from Ar, NH{sub 3}, N{sub 2}, CH{sub 4}, and C{sub 2}H{sub 2} gases. Individual targets with surface areas as large as {approximately}4 m{sup 2}, or weighing up to 1200 kg, have been treated in the large LANL facility. In collaboration with General Motors and the University of Wisconsin, a process has been developed for application of hard, low friction, diamond-like-carbon layers on assemblies of automotive pistons. Numerical simulations have been performed using a 2{1/2}-D particle- in-cell code, which yields time-dependent implantation energy, dose, and angle of arrival for ions at the target surface for realistic geometries. Plasma source development activities include the investigation of pulsed, inductively coupled sources capable of generating highly dissociated N{sup +} with ion densities n{sub i} {approximately} 10{sup 11}/cm{sup 3}, at {approximately}100 W average input power. Cathodic arc sources have also been used to produce filtered metallic and C plasmas for implantation and deposition either in vacuum, or in conjunction with a background gas for production of highly adherent ceramic coatings.
Munson, C.P.; Faehl, R.J.; Henins, I. [and others
MPD streaming plasma source for MFTF
The applicability of Magneto-plasma-dynamic (MPD) arcs as a source of warm, streaming plasma for start-up and for the suppression of instabilities is discussed. The plasma source emits a high particle flux (1000-5000 amp) of well directed ions having kinetic energy in the 10-100 eV range. The construction details of an MPD plasma source are given and a sequence of proposed tests are presented. The tests are designed to demonstrate the large flux and good gas utilization of the source as well as investigate the behavior of the streaming plasma in a high magnetic field environment.
Poulsen, P.
Application of High Power DC Arc Plasma for
Recent results in the R&D of thin diamond film coated WC-Co drills and end ... of High Quality Freestanding Diamond Films and Diamond Film Coated Cutting ...
Comparative Study of Laser Cladded and Plasma Transferred Arc ...
J10: Mechanical Properties and Welding Conditions of Monopile and Transition for Offshore Wind Plant · J12: Microstructure and Mechanical Properties of ...
Cathodic Arc Plasma System with Twist Filter: Advanced ...
See More Ion Sources and Beams Technologies. Contact Us. Receive Customized Tech Alerts. Tech Transfer Site Map. Last updated: 09/17/2009.
Surface Treatment of Aluminum Alloys by Atmospheric Plasma Arc ...
DRI Carburization in the Reduction and Transition Zones of a Shaft Furnace MIDREX Type · Effect of Casting Speed on Temperature Difference between ...
Cathodic Arc Plasma System with Twist Filter - Triggerless method ...
Medical Imaging Mouse Models; Research Tools; Developing World; Energy. Energy Efficiency; Energy Storage and Recovery; Renewable Energy; Environmental Technologies.
Chemical vapor deposition thin films as biopassivation coatings and directly patternable dielectrics
Organosilicon thin films deposited by pulsed plasma-enhanced chemical vapor deposition (PPECVD) and hot-filament chemical vapor deposition (HFCVD) were investigated as potential biopassivation coatings for neural probes. ...
Pryce Lewis, Hilton G. (Hilton Gavin), 1973-
Fuel gas production by microwave plasma in liquid
We propose to apply plasma in liquid to replace gas-phase plasma because we expect much higher reaction rates for the chemical deposition of plasma in liquid than for chemical vapor deposition. A reactor for producing microwave plasma in a liquid could produce plasma in hydrocarbon liquids and waste oils. Generated gases consist of up to 81% hydrogen by volume. We confirmed that fuel gases such as methane and ethylene can be produced by microwave plasma in liquid.
Nomura, Shinfuku; Toyota, Hiromichi; Tawara, Michinaga; Yamashita, Hiroshi; Matsumoto, Kenya [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577 (Japan); Shikoku Industry and Technology Promotion Center, 2-5 Marunouchi, Takamatsu, Kagawa 760-0033 (Japan)
Arc Flash Issues in Transmission and Substation Environments: Modeling of Incident Thermal Energy of Long Arcs
Arc flashes are a serious hazard that may put people in life-threatening situations and cause great damage to existing assets. The National Electrical Safety Code (NESC) and the Occupational Safety and Health Administration (OSHA) introduced requirements for electric utilities to perform arc flash hazard assessment of their facilities operating at and above 1000 V. Most methods available at this time for analyzing the incident thermal energy of arc flash were developed for low and medium-voltage industri...
Detection of arcs in automotive electrical systems
At the present time, there is no established method for the detection of DC electric arcing. This is a concern for forthcoming advanced automotive electrical systems which consist of higher DC electric power bus voltages, ...
Mishrikey, Matthew David
A project to provide information on the hazards associated wlth arc melting of Th is described. A general airsampling analysis was made to determine the separation, concentration, and distribution of Th daughter (decay) products throughout arc melting, machining, and forging processes found in a handling facility. The value of well coordinated health physics program is stressed in connection with potential health hazards and personnel protection. Building, equipment, and exhaust ventilation requirements for such a facility are discussed, along wlth special handling methods. (auth)
Lowery, R.R.
Groundwater Data Modeling for Arc Hydro
During the years 1999–2002, a consortium for geographic information systems (GIS) in water resources, led by the Center for Research in Water Resources (CRWR) and the Environmental Systems Research Institute (ESRI), developed a data model, named Arc Hydro, for the presentation of surface water data in ArcGIS. This model was published in the summer of 2002 (Maidment, 2002) and has since been adopted as a common framework by data producing agencies, such as the USGS, and by creators of hydrologic models requiring GIS data such as the Hydrologic Engineering Center and the Danish Hydraulic Institute. The Design of Arc Hydro revealed that it is possible to define a "hydrologic information system " which is a synthesis of geospatial and temporal data supporting hydrologic analysis and modeling (Maidment, 2002). This is an exciting new concept because rather than simply applying GIS in water resources, it provides a new way of thinking about how information technology can be used to support water resources planning, modeling and management. While the first Arc Hydro data model focused on describing surface water behavior, it has become apparent that a similar effort is needed to define an ArcGIS data model for groundwater, as part of Arc Hydro. This need is emphasized by the lack of a well understood and generally agreed
unknown authors
A statistical analysis of the effect of PECVD deposition parameters on surface and bulk recombination in silicon solar cells
We have performed a statistically designed multiparameter experiment using response surface methodology to determine the optimum deposition and anneal conditions for PECVD silicon-oxide and silicon-nitride films on Si solar cells. Our process includes a unique in situ hydrogen plasma treatment to promote bulk defect passivation independently of surface effects. Our goal has been to define a process to optimize cell performance by minimizing recombination while also providing an effective antireflection coating. Our initial results show that excellent emitter-surface passivation, approaching that of the best thermally grown oxides, can be obtained using a single-layer nitride coating whose refractive index is optimized for antireflection purposes. Use of the PECVD-nitride instead of a TiO{sub 2} ARC resulted in an 11% increase in output power.
Ruby, D.S. [Sandia National Labs., Albuquerque, NM (United States); Wilbanks, W.L.; Fleddermann, C.B. [Univ. of New Mexico, Albuquerque, NM (United States)
Quantum cascade laser investigations of CH{sub 4} and C{sub 2}H{sub 2} interconversion in hydrocarbon/H{sub 2} gas mixtures during microwave plasma enhanced chemical vapor deposition of diamond
CH{sub 4} and C{sub 2}H{sub 2} molecules (and their interconversion) in hydrocarbon/rare gas/H{sub 2} gas mixtures in a microwave reactor used for plasma enhanced diamond chemical vapor deposition (CVD) have been investigated by line-of-sight infrared absorption spectroscopy in the wavenumber range of 1276.5-1273.1 cm{sup -1} using a quantum cascade laser spectrometer. Parameters explored include process conditions [pressure, input power, source hydrocarbon, rare gas (Ar or Ne), input gas mixing ratio], height (z) above the substrate, and time (t) after addition of hydrocarbon to a pre-existing Ar/H{sub 2} plasma. The line integrated absorptions so obtained have been converted to species number densities by reference to the companion two-dimensional (r,z) modeling of the CVD reactor described in Mankelevich et al. [J. Appl. Phys. 104, 113304 (2008)]. The gas temperature distribution within the reactor ensures that the measured absorptions are dominated by CH{sub 4} and C{sub 2}H{sub 2} molecules in the cool periphery of the reactor. Nonetheless, the measurements prove to be of enormous value in testing, tensioning, and confirming the model predictions. Under standard process conditions, the study confirms that all hydrocarbon source gases investigated (methane, acetylene, ethane, propyne, propane, and butane) are converted into a mixture dominated by CH{sub 4} and C{sub 2}H{sub 2}. The interconversion between these two species is highly dependent on the local gas temperature and the H atom number density, and thus on position within the reactor. CH{sub 4}->C{sub 2}H{sub 2} conversion occurs most efficiently in an annular shell around the central plasma (characterized by 1400CH{sub 4} is favored in the more distant regions where T{sub gas}C{sub 2}H{sub 2} conversion, whereas the reverse C{sub 2}H{sub 2}->CH{sub 4} process only requires H atoms to drive the reactions; H atoms are not consumed by the overall conversion.
Ma Jie; Cheesman, Andrew; Ashfold, Michael N. R. [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Hay, Kenneth G.; Wright, Stephen; Langford, Nigel; Duxbury, Geoffrey [Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom); Mankelevich, Yuri A. [Skobel'tsyn Institute of Nuclear Physics, Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation)
Method for cracking hydrocarbon compositions using a submerged reactive plasma system
A method for cracking a liquid hydrocarbon composition (e.g. crude oil) to produce a cracked hydrocarbon product. A liquid hydrocarbon composition is initially provided. An electrical arc is generated directly within the hydrocarbon composition so that the arc is entirely submerged in the composition. Arc generation is preferably accomplished using a primary and secondary electrode each having a first end submerged in the composition. The first ends of the electrodes are separated from each other to form a gap therebetween. An electrical potential is then applied to the electrodes to generate the arc within the gap. A reactive gas is thereafter delivered to the arc which forms a bubble around the arc. Gas delivery may be accomplished by providing a passageway through each electrode and delivering the gas through the passageways. The arc and gas cooperate to produce a plasma which efficiently cracks the hydrocarbon composition.
Kong, Peter C. (Idaho Falls, ID)
A method is described for cracking a liquid hydrocarbon composition (e.g. crude oil) to produce a cracked hydrocarbon product. A liquid hydrocarbon composition is initially provided. An electrical arc is generated directly within the hydrocarbon composition so that the arc is entirely submerged in the composition. Arc generation is preferably accomplished using a primary and secondary electrode each having a first end submerged in the composition. The first ends of the electrodes are separated from each other to form a gap there between. An electrical potential is then applied to the electrodes to generate the arc within the gap. A reactive gas is thereafter delivered to the arc which forms a bubble around the arc. Gas delivery may be accomplished by providing a passageway through each electrode and delivering the gas through the passageways. The arc and gas cooperate to produce a plasma which efficiently cracks the hydrocarbon composition. 6 figs.
Kong, P.C.
Microwave Plasma Chemical Vapor Deposition of Carbon Coatings on LiNi1/3Co1/3Mn1/3O2 for Li-Ion Battery Composite Cathodes
In this paper, we report results of a novel synthesis method of thin film conductive carbon coatings on LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} cathode active material powders for lithium-ion batteries. Thin layers of graphitic carbon were produced from a solid organic precursor, anthracene, by a one-step microwave plasma chemical vapor deposition (MPCVD) method. The structure and morphology of the carbon coatings were examined using SEM, TEM, and Raman spectroscopy. The composite LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} electrodes were electrochemically tested in lithium half coin cells. The composite cathodes made of the carbon-coated LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} powder showed superior electrochemical performance and increased capacity compared to standard composite LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} electrodes.
Doeff, M.M.; Kostecki, R.; Marcinek, M.; Wilcoc, J.D.
Magnetic Method to Characterize the Current Densities in Breaker Arc
The purpose of this research was to use magnetic induction measurements from a low voltage breaker arc, to reconstruct the arc's current density. The measurements were made using Hall effect sensors, which were placed close to, but outside the breaking device. The arc was modelled as a rectangular current sheet, composed of a mix of threadlike current segments and with a current density varying across the propagation direction. We found the magnetic induction of the arc is a convolution product of the current density, and a function depending on the breaker geometry and arc model. Using deconvolution methods, the current density in the electric arc was determined.The method is used to study the arc behavior into the breaker device. Notably, position, arc size, and electric conductivity could all be determined, and then used to characterize the arc mode, diffuse or concentrated, and study the condition of its mode changing.
Machkour, Nadia [National Institute of Standards and Technology (United States)
Ion source with improved primary arc collimation
An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.
Dagenhart, W.K.
Subduction Controls of Hf and Nd Isotopes in Lavas of the Aleutian Island Arc
of the subducted slab on Aleutian Island Arc magma sources:2006. Revised age of Aleutian Island arc formation impliesCrustal recycling and the Aleutian arc. Geochim Cosmochim.
Yogodzinski, Gene
Large-scale pulsed laser deposition Nini Pryds, AFM, Jrgen Schou, OPL, Finn Saxild, AFM and Sren Linderoth,AFM
; OPL, Department of Optics and Plasma Research) e-mail: firstname.lastname@example.com Pulsed laser deposition (PLD
A Study Of Scale Deposition- An Analogue Of Meso- To Epithermal Ore
Study Of Scale Deposition- An Analogue Of Meso- To Epithermal Ore Study Of Scale Deposition- An Analogue Of Meso- To Epithermal Ore Formation In The Volcano Of Milos, Aegean Arc, Greece Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Study Of Scale Deposition- An Analogue Of Meso- To Epithermal Ore Formation In The Volcano Of Milos, Aegean Arc, Greece Details Activities (0) Areas (0) Regions (0) Abstract: The viability of boiling as a mechanism for meso- to epithermal ore formation has been tested in the Milos volcano, Aegean Island Arc, by investigating rates of deposition and composition of scale, and by drawing an analogy between the results and actual field occurrences on the island. Milos offers ideal conditions for such testing: it consists of predominantly felsic volcanic rocks with numerous late-stage hydrovolcanic
An apparatus and method are given for forming a welding arc which is rotated by a magnetic field very rapidly about an annular electrode so that a weld is produced simultaneously over all points of an annular or closed path. This invention inhibits outgassing from the jacket of a fuel slug which is being welded by adjusting the pressure throughout the welding cycle to establish a balance between the gas pressure within the jacket and that of the atmosphere surrounding the jacket. Furthermore, an improved control of the magnetic field producing rotation of the welding arc is disclosed whereby this rotation is prevented from splashing about the metal being welded as the welding arc makes it molten.
Noland, R.A.; Stone, C.C.
arcControlTower: the System for Atlas Production and Analysis on ARC
PanDA, the Atlas management and distribution system for production and analysis jobs on EGEE and OSG clusters, is based on pilot jobs to increase the throughput and stability of the job execution on grid. The ARC middleware uses specific approach which tightly connects the job requirements with cluster capabilities like resource usage, software availability and caching of input files. The pilot concept renders the ARC features useless. The arcControlTower is the job submission system which merges the pilot benefits and ARC advantages. It takes the pilot payload from the panda server and submits the jobs to the Nordugrid ARC clusters as regular jobs, with all the job resources known in advance. All the pilot communication with the PanDA server is done by the arcControlTower, so it plays the role of a pilot factory and the pilot itself. There are several advantages to this approach: no grid middleware is needed on the worker nodes, the fair-share between the production and user jobs is tuned with the arcControl...
Filipcic, A; The ATLAS collaboration
Corrosion and arc erosion in MHD channels
The objective of this task is to study the corrosion and arc erosion of MHD materials in a cooperative effort with, and to support, the MHD topping cycle program. Materials tested in the Avco Research Laboratory/Textron facility, or materials which have significant MHD importance, will be analyzed to document their physical deterioration. Conclusions shall be drawn about their wear mechanisms and lifetime in the MHD environment with respect to the following issues; sulfur corrosion, electrochemical corrosion, and arc erosion. The impact of any materials or slag conditions on the level of power output and on the level of leakage current in the MHD channel will also be noted, where appropriate.
Rosa, R.J. (Montana State Univ., Bozeman, MT (United States). Dept. of Mechanical Engineering); Pollina, R.J. (Montana State Univ., Bozeman, MT (United States). Dept. of Mechanical Engineering Avco-Everett Research Lab., Everett, MA (United States))
Ion source based on the cathodic arc
A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.
Sanders, D.M.; Falabella, S.
Plasma immersion surface modification with metal ion plasma
We describe here a novel technique for surface modification in which metal plasma is employed and by which various blends of plasma deposition and ion implantation can be obtained. The new technique is a variation of the plasma immersion technique described by Conrad and co-workers. When a substrate is immersed in a metal plasma, the plasma that condenses on the substrate remains there as a film, and when the substrate is then implanted, qualitatively different processes can follow, including' conventional' high energy ion implantation, recoil implantation, ion beam mixing, ion beam assisted deposition, and metallic thin film and multilayer fabrication with or without species mixing. Multiple metal plasma guns can be used with different metal ion species, films can be bonded to the substrate through ion beam mixing at the interface, and multilayer structures can be tailored with graded or abrupt interfaces. We have fabricated several different kinds of modified surface layers in this way. 22 refs., 4 figs.
Brown, I.G.; Yu, K.M. (Lawrence Berkeley Lab., CA (USA)); Godechot, X. (Lawrence Berkeley Lab., CA (USA) Societe Anonyme d'Etudes et Realisations Nucleaires (SODERN), 94 - Limeil-Brevannes (France))
SciTech Connect: plasma
plasma Find plasma Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced Ă— Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)
American Ref Fuel Corporation ARC | Open Energy Information
Ref Fuel Corporation ARC Jump to: navigation, search Name American Ref-Fuel Corporation (ARC) Place Montvale, NJ, New Jersey Zip 76450 Product Focused on waste-to-energy facilities...
DOE Solar Decathlon: News Blog » SCI-Arc/Caltech
SCI-ArcCaltech Below you will find Solar Decathlon news from the SCI-ArcCaltech archive, sorted by date. New Zealand Takes First in Engineering Contest Thursday, September 29,...
Using Plasmas for High-Speed Flow Control and Combustion Control.
??Experiments on characterization of Localized Arc Filament Plasma Actuators used for high-speed flow control, as well as experimental studies of chemiluminescence and chemi-ionization for flame… (more)
Keshav, Saurabh
Atmospheric Pressure Plasma Process And Applications
This paper provides a general discussion of atmospheric-pressure plasma generation, processes, and applications. There are two distinct categories of atmospheric-pressure plasmas: thermal and nonthermal. Thermal atmospheric-pressure plasmas include those produced in high intensity arcs, plasma torches, or in high intensity, high frequency discharges. Although nonthermal plasmas are at room temperatures, they are extremely effective in producing activated species, e.g., free radicals and excited state atoms. Thus, both thermal and nonthermal atmosphericpressure plasmas are finding applications in a wide variety of industrial processes, e.g. waste destruction, material recovery, extractive metallurgy, powder synthesis, and energy conversion. A brief discussion of recent plasma technology research and development activities at the Idaho National Laboratory is included.
Peter C. Kong; Myrtle
Synthesis of Diamond-like Carbon Films by Electro-Plasma ...
LITTLEWOOD TYPE PROBLEMS ON SUB ARCS Peter ... - CECM
LITTLEWOOD TYPE. PROBLEMS ON SUB ARCS. Peter Borwein. Simon Fraser University Centre for. Constructive and Experimental. Mathematics.
Toughened Graphite Electrode for High Heat Electric Arc ...
Energy Innovation Portal Technologies. ... To reduce the failure rate, ... Applications and Industries. Electric arc furnace steel manufacturing;
Synthesis of Elementary Net Systems with Context Arcs and Localities
We investigate the synthesis problem for ENCL-systems, defined as Elementary Net Systems extended with context (inhibitor and activator) arcs and explicit event localities. Since colocated events are meant to be executed synchronously, the behaviour ... Keywords: Petri nets, activator arcs, context arcs, elementary net systems, inhibitor arcs, localities, net synthesis, step sequence semantics, structure and behaviour of nets, theory of concurrency, theory of regions, transition systems
Maciej Koutny; Marta Pietkiewicz-Koutny
Gas tungsten arc welder with electrode grinder
A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.
Christiansen, David W. (Kennewick, WA); Brown, William F. (West Richland, WA)
Out-arc pancyclicity of vertices in tournaments
Yao, Guo and Zhang [T. Yao, Y. Guo, K. Zhang, Pancyclic out-arcs of a vertex in a tournament, Discrete Appl. Math. 99 (2000) 245-249.] proved that every strong tournament contains a vertex u such that every out-arc of u is pancyclic. In this paper, we ... Keywords: Cycles, Out-arcs, Pancyclicity, Tournaments
Qiaoping Guo; Shengjia Li; Yubao Guo; Hongwei Li
arcControlTower, the System for Atlas Production and Analysis on ARC
Abstract content Panda, the Atlas management and distribution system for production and analysis jobs on EGEE and OSG clusters, is based on pilot jobs to increase the throughput and stability of the job execution on grid. The ARC middleware uses specific approach which tightly connects the job requirements with cluster capabilities like resource usage, software availability and caching of input files. The pilot concept renders the ARC features useless. The arcControlTower is the job submission system which merges the pilot benefits and ARC advantages. It takes the pilot payload from the panda server and submits the jobs to the Nordugrid ARC clusters as regular jobs, with all the resources known in advance. All the pilot communication with the panda server is done by the arcControlTower, so it plays the role of a pilot factory and the pilot itself. There are several advantages to this approach: no grid middleware is needed on the worker nodes, the fair-share between the production and user jobs is tuned with t...
Fuel injector utilizing non-thermal plasma activation
A non-thermal plasma assisted combustion fuel injector that uses an inner and outer electrode to create an electric field from a high voltage power supply. A dielectric material is operatively disposed between the two electrodes to prevent arcing and to promote the formation of a non-thermal plasma. A fuel injector, which converts a liquid fuel into a dispersed mist, vapor, or aerosolized fuel, injects into the non-thermal plasma generating energetic electrons and other highly reactive chemical species.
Coates, Don M. (Santa Fe, NM); Rosocha, Louis A. (Los Alamos, NM)
Microwave plasma chemical vapor deposition of nano ...
radiation was also applied for rapid heating of solutions ... of the system was designed to generate Ar ... model JEOL 200CX), and scanning electron ...
Functionalization of Hydrogen-free Diamond-like Carbon Films using Open-air Dielectric Barrier Discharge Atmospheric Plasma Treatments
A dielectric barrier discharge (DBD) technique has been employed to produce uniform atmospheric plasmas of He and N2 gas mixtures in open air in order to functionalize the surface of filtered-arc deposited hydrogen-free diamond-like carbon (DLC) films. XPS measurements were carried out on both untreated and He/N2 DBD plasma treated DLC surfaces. Chemical states of the C 1s and N 1s peaks were collected and used to characterize the surface bonds. Contact angle measurements were also used to record the short- and long-term variations in wettability of treated and untreated DLC. In addition, cell viability tests were performed to determine the influence of various He/N2 atmospheric plasma treatments on the attachment of osteoblast MC3T3 cells. Current evidence shows the feasibility of atmospheric plasmas in producing long-lasting variations in the surface bonding and surface energy of hydrogen-free DLC and consequently the potential for this technique in the functionalization of DLC coated devices.
Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Instituto de Materiales de Madrid, C.S.I.C., Cantoblanco, 28049 Madrid, Spain; Instituto de Quimica-Fisica" Rocasolano" C.S.I.C., 28006 Madrid, Spain; Mahasarakham University, Mahasarakham 44150, Thailand; CASTI, CNR-INFM Regional Laboratory, L' Aquila 67100, Italy; SUNY Upstate Medical University, Syracuse, NY 13210, USA; Endrino, Jose; Endrino, J. L.; Marco, J. F.; Poolcharuansin, P.; Phani, A.R.; Allen, M.; Albella, J. M.; Anders, A.
Thermal plasma processing of materials
Emphasis has been on plasma synthesis of fine powders, plasma Chemical Vapor Deposition (CVD), on related diagnostics, and on modeling work. Since plasma synthesis as well as plasma CVD make frequent use of plasma jets, the beginning has been devoted of plasma jets and behavior of particulates injected into such plasma jets. Although most of the construction of the Triple-Torch Plasma Reactor (TTPR) has already been done, modifications have been made in particular modifications required for plasma CVD of diamond. A new reactor designed for Counter-Flow Liquid Injection Plasma Synthesis (CFLIPS) proved to be an excellent tool for synthesis of fine powders as well as for plasma CVD. An attempt was made to model flow and temperature fields in this reactor. Substantial efforts were made to single out those parameters which govern particle size, size distribution, and powder quality in our plasma synthesis experiments. This knowledge is crucial for controlling the process and for meaningful diagnostics and modeling work. Plasma CVD of diamond films using both reactors has been very successful and we have been approached by a number of companies interested in using this technology for coating of tools.
Pfender, E.; Heberlein, J.
Hybrid Arc Cell Studies: Status Report
I report on the status, at the end of FY12, of the studies of an arc cell for a hybrid synchrotron accelerating from 375 GeV/c to 750 GeV/c in momentum. Garren produced a complete lattice that gives a good outline of the structure of a hybrid synchrotron lattice. It is, however, lacking in some details: it does not maintain a constant time of flight, it lacks chromaticity correction, its cell structure is not ideal for removing aberrations from chromaticity correction, and it probably needs more space between magnets. I have begun studying cell structures for the arc cells to optimize the lattice performance and cost. I present some preliminary results for two magnets per half cell. I then discuss difficulties encountered, some preliminary attempts at resolving them, and the future plans for this work.
Berg J. S.
Effect of O{sub 2} gas partial pressure on mechanical properties of Al{sub 2}O{sub 3} films deposited by inductively coupled plasma-assisted radio frequency magnetron sputtering
The effect of O{sub 2} partial pressure on the mechanical properties of Al{sub 2}O{sub 3} films is studied. Using films prepared by inductively coupled plasma-assisted radio frequency magnetron sputtering, the deposition rate of Al{sub 2}O{sub 3} decreases rapidly when oxygen is added to the argon sputtering gas. The internal stresses in the films are compressive, with magnitude decreasing steeply from 1.6 GPa for films sputtered in pure argon gas to 0.5 GPa for films sputtered in argon gas at an O{sub 2} partial pressure of 0.89 Multiplication-Sign 10{sup -2} Pa. Stress increases gradually with increasing O{sub 2} partial pressure. Using a nanoindentation tester with a Berkovich indenter, film hardness was measured to be about 14 GPa for films sputtered in pure argon gas. Hardness decreases rapidly on the addition of O{sub 2} gas, but increases when the O{sub 2} partial pressure is increased. Adhesion, measured using a Vickers microhardness tester, increases with increasing O{sub 2} partial pressure. Electron probe microanalyzer measurements reveal that the argon content of films decreases with increasing O{sub 2} partial pressure, whereas the O to Al composition ratio increases from 1.15 for films sputtered in pure argon gas to 1.5 for films sputtered in argon gas at O{sub 2} partial pressures over 2.4 Multiplication-Sign 10{sup -2} Pa. X-ray diffraction measurements reveal that films sputtered in pure argon gas have an amorphous crystal structure, whereas {gamma}-Al{sub 2}O{sub 3} is produced for films sputtered in argon gas with added O{sub 2} gas. Atomic force microscopy observations reveal that the surface topography of sputtered Al{sub 2}O{sub 3} films changes from spherical to needlelike as O{sub 2} partial pressure is increased. Fracture cross sections of the films observed by scanning electron microscopy reveal that the film morphology exhibits no discernible features at all O{sub 2} partial pressures.
Fujiyama, Hirokazu; Sumomogi, Tsunetaka; Nakamura, Masayoshi [Faculty of Engineering, Fukuoka Institute of Technology, 3-30-1 Wajirohigashi, Higashi-ku, Fukuoka 811-0295 (Japan); Faculty of Engineering, Hiroshima Kokusai Gakuin University, 6-20-1 Nakano, Aki-ku, Hiroshima 739-0321 (Japan)
Surface breakdown igniter for mercury arc devices
Surface breakdown igniter comprises a semiconductor of medium resistivity which has the arc device cathode as one electrode and has an igniter anode electrode so that when voltage is applied between the electrodes a spark is generated when electrical breakdown occurs over the surface of the semiconductor. The geometry of the igniter anode and cathode electrodes causes the igniter discharge to be forced away from the semiconductor surface.
Bayless, John R. (Malibu, CA)
Method for depositing high-quality microcrystalline semiconductor materials
A process for the plasma deposition of a layer of a microcrystalline semiconductor material is carried out by energizing a process gas which includes a precursor of the semiconductor material and a diluent with electromagnetic energy so as to create a plasma therefrom. The plasma deposits a layer of the microcrystalline semiconductor material onto the substrate. The concentration of the diluent in the process gas is varied as a function of the thickness of the layer of microcrystalline semiconductor material which has been deposited. Also disclosed is the use of the process for the preparation of an N-I-P type photovoltaic device.
Guha, Subhendu (Bloomfield Hills, MI); Yang, Chi C. (Troy, MI); Yan, Baojie (Rochester Hills, MI)
Spark Plasma Sintering of Amorphous Coatings on Metallic Substrate
In the present work, we will discuss the results of deposition of amorphous coatings on metallic substrates using spark plasma sintering method. The influence of ...
Experimental and theoretical study of exhaust gas fuel reforming of Diesel fuel by a non-thermal arc discharge for syngas production
-thermal arc discharge for syngas production A. Lebouvier1,2 , F. Fresnet2 , F. Fabry1 , V. Boch2 , V. Rohani1% and a conversion rate of 95% have been reached which correspond to a syngas dry molar fraction of 25%. For the most and promote H2O and CO2 production. Keywords: Plasma reformer, syngas, diesel fuel reforming, NOx trap. 1
Paris-Sud XI, Université de
Apparatus for coating a surface with a metal utilizing a plasma source
An apparatus and method are disclosed for coating or layering a surface with a metal utilizing a metal vapor vacuum arc plasma source. The apparatus includes a trigger mechanism for actuating the metal vacuum vapor arc plasma source in a pulsed mode at a predetermined rate. The surface or substrate to be coated or layered is supported in position with the plasma source in a vacuum chamber. The surface is electrically biased for a selected period of time during the pulsed mode of operation of the plasma source. Both the pulsing of the metal vapor vacuum arc plasma source and the electrical biasing of the surface are synchronized for selected periods of time. 10 figures.
Brown, I.G.; MacGill, R.A.; Galvin, J.E.
Volumetric modulated arc radiotherapy for esophageal cancer
A treatment planning study was performed to evaluate the performance of volumetric arc modulation with RapidArc (RA) against 3D conformal radiation therapy (3D-CRT) and conventional intensity-modulated radiation therapy (IMRT) techniques for esophageal cancer. Computed tomgraphy scans of 10 patients were included in the study. 3D-CRT, 4-field IMRT, and single-arc and double-arc RA plans were generated with the aim to spare organs at risk (OAR) and healthy tissue while enforcing highly conformal target coverage. The planning objective was to deliver 54 Gy to the planning target volume (PTV) in 30 fractions. Plans were evaluated based on target conformity and dose-volume histograms of organs at risk (lung, spinal cord, and heart). The monitor unit (MU) and treatment delivery time were also evaluated to measure the treatment efficiency. The IMRT plan improves target conformity and spares OAR when compared with 3D-CRT. Target conformity improved with RA plans compared with IMRT. The mean lung dose was similar in all techniques. However, RA plans showed a reduction in the volume of the lung irradiated at V{sub 20Gy} and V{sub 30Gy} dose levels (range, 4.62-17.98%) compared with IMRT plans. The mean dose and D{sub 35%} of heart for the RA plans were better than the IMRT by 0.5-5.8%. Mean V{sub 10Gy} and integral dose to healthy tissue were almost similar in all techniques. But RA plans resulted in a reduced low-level dose bath (15-20 Gy) in the range of 14-16% compared with IMRT plans. The average MU needed to deliver the prescribed dose by RA technique was reduced by 20-25% compared with IMRT technique. The preliminary study on RA for esophageal cancers showed improvements in sparing OAR and healthy tissue with reduced beam-on time, whereas only double-arc RA offered improved target coverage compared with IMRT and 3D-CRT plans.
Vivekanandan, Nagarajan, E-mail: email@example.com [Department of Medical Physics, Cancer Institute, Chennai (India); Sriram, Padmanaban; Syam Kumar, S.A.; Bhuvaneswari, Narayanan; Saranya, Kamalakannan [Department of Medical Physics, Cancer Institute, Chennai (India)
Contrib. Plasma Phys. 52, No. 10, 789 794 (2012) / DOI 10.1002/ctpp.201200076 Recent Progress in Complex Plasmas
" at the Universities in Greifswald and Kiel as well as at the Leibniz-Institute for Plasma Research and Technology interacting with solid surfaces, see Fig. 1. The importance of complex plasma research derives from of nanotechnology including plasma-assisted deposition or etching. The 2007 review on plasma research and its
Fehske, Holger
Plasma shield for in-air beam processes
A novel concept/apparatus, the Plasma Shield, is introduced in this paper. The purpose of the Plasma Shield is designed to shield a target object chemically and thermally by engulfing an area subjected to beam treatment with inert plasma. The shield consists of a vortex-stabilized arc that is employed to shield beams and workpiece area of interaction from an atmospheric or liquid environment. A vortex-stabilized arc is established between a beam generating device (laser, ion or electron gun) and a target object. The arc, which is composed of a pure noble gas, engulfs the interaction region and shields it from any surrounding liquids like water or reactive gases. The vortex is composed of a sacrificial gas or liquid that swirls around and stabilizes the arc. The successful Plasma Shield was experimentally established and very high-quality electron beam welding with partial plasma shielding was performed. The principle of the operation and experimental results are discussed in the paper.
Hershcovitch, Ady [Collider-Accelerator Department, Building 901A, Brookhaven National Laboratory, Upton, New York 11973 (United States)
Arc Flash Issues in Transmission and Substation Environments
Arc flashes are a serious hazard that may potentially put people in life-threatening situations and cause great damage to existing assets. National Electrical Safety Code and Occupational Safety and Health Administration safety rules have introduced requirements for electric utilities to perform arc-flash hazard analysis of all electric facilities operating at and above 1000 volts. Most methods available at this time for analyzing the arc-flash incident thermal energy were developed for low- and medium-v...
This patent describes apparatus for producing an electricity neutral ionized gas discharge, termed a plasma, substantially free from contamination with neutral gas particles. The plasma generator of the present invention comprises a plasma chamber wherein gas introduced into the chamber is ionized by a radiofrequency source. A magnetic field is used to focus the plasma in line with an exit. This magnetic field cooperates with a differential pressure created across the exit to draw a uniform and uncontaminated plasma from the plasma chamber.
Foster, J.S. Jr.
Recovering Zinc and Lead from Electric Arc Furnace Dust
Aug 1, 2000 ... Non-member price: 25.00. TMS Student Member price: 10.00. Product In Stock. Description Increasing amounts of electric arc furnace dust ...
Corrosion Behavior of Twin Wire Arc Sprayed Inconel Coating
Presentation Title, Corrosion Behavior of Twin Wire Arc Sprayed Inconel Coating. Author(s), Sofiane Djeraf, Yamina Mebdoua, Hadj Lahmar, Rachid Lakhdari.
Combinatorics of Arc Diagrams, Ferrers Fillings, Young ... - CECM
Jul 22, 2009 ... I Generalization of permutation matrices: fill each row & column of a Ferrers shape ... Standard Young Tableaux. Arc Diagrams,. Nesting and.
Effects of Arc Welding Process on Microstructure and Morphology of ...
Presentation Title, Effects of Arc Welding Process on Microstructure and Morphology of Flake Graphite in Grey Cast Iron. Author(s), Arash Elhami Khorasani, ...
ArcSafe® with Pulsed Arrested Spark Discharge
stress, aging electrical wiring systems, arc-physics, electrostatic dis- charge, and TEMPEST. R. Kevin Howard is a principle technologist with the Electromagnetic Technologies...
A model-based approach to intelligent control of gas metal arc welding
This paper discusses work on a model-based intelligent process controller for gas metal arc welding. Four sensors input to a neural network, which communicates to a reference model-based adaptive controller that controls process parameters. Reference model derivation and validation are discussed. The state of an arch weld is determined by the composition of the weld and base metal and the weld's thermomechanical history. The composition of the deposited weld metal depends primarily on the amount of filler metal dilution; heat input to the weld, comprising pre-heat and process heat, is the controlling factor in the thermal cycle. Thus, control of the arc welding process should focus on rational specification and in-process control of the heat and mass input to the weld. A control model has been developed in which the governing equations are solved for the process parameters as functions of the desired heat input (in terms of heat input unit weld length) and mass input (in terms of transverse reinforcement area) to the weld. The model includes resistive and arc heating of the electrode wire, characteristics of the welding power supply, and a volumetric heat balance on the electrode material, as well as latent and superheat of the electrode material. Extension of the model to include dynamics of individual droplet transfer events, based on incorporating a nonlinear, lumped parameter droplet analysis, is discussed. A major emphasis has been placed on computational simplicity; model solutions are required at the rate of about 10 Hz during welding. Finally, a process control scheme has been developed for the gas metal arc welding process using the above nonlinear model with a proportional-integral controller with adaptive coefficients to control the weld heat input and reinforcement area independently. Performance of the resulting control method is discussed. 10 refs., 5 figs.
Smartt, H.B.; Johnson, J.A.; Einerson, C.J.; Watkins, A.D.; Carlson, N.M.
Method for controlling gas metal arc welding
The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.
Smartt, H.B.; Einerson, C.J.; Watkins, A.D.
The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.
Smartt, Herschel B. (Idaho Falls, ID); Einerson, Carolyn J. (Idaho Falls, ID); Watkins, Arthur D. (Idaho Falls, ID)
Spectrographic temperature measurement of a high power breakdown arc in a high pressure gas switch
A procedure for obtaining an approximate temperature value of conducting plasma generated during self-break closure of a RIMFIRE gas switch is described. The plasma is in the form of a breakdown arc which conducts approximately 12 kJ of energy in 1 {mu}s. A spectrographic analysis of the trigger-section of the 6-MV RIMFIRE laser triggered gas switch used in Sandia National Laboratory's ''Z-Machine'' has been made. It is assumed that the breakdown plasma has sufficiently approached local thermodynamic equilibrium allowing a black-body temperature model to be applied. This model allows the plasma temperature and radiated power to be approximated. The gas dielectric used in these tests was pressurized SF{sub 6}. The electrode gap is set at 4.59 cm for each test. The electrode material is stainless steel and insulator material is poly(methyl methacrylate). A spectrum range from 220 to 550 nanometers has been observed and calibrated using two spectral irradiance lamps and three spectrograph gratings. The approximate plasma temperature is reported.
Yeckel, Christopher; Curry, Randy [Department of Computer and Electrical Engineering, Center for Physical and Power Electronics, University of Missouri--Columbia, Columbia, Missouri 65211 (United States)
Plasma vitrification of waste materials
This invention provides a process wherein hazardous or radioactive wastes in the form of liquids, slurries, or finely divided solids are mixed with finely divided glassformers (silica, alumina, soda, etc.) and injected directly into the plume of a non-transferred arc plasma torch. The extremely high temperatures and heat transfer rates makes it possible to convert the waste-glassformer mixture into a fully vitrified molten glass product in a matter of milliseconds. The molten product may then be collected in a crucible for casting into final wasteform geometry, quenching in water, or further holding time to improve homogeneity and eliminate bubbles. 4 figs.
McLaughlin, D.F.; Dighe, S.V.; Gass, W.R.
This invention provides a process wherein hazardous or radioactive wastes in the form of liquids, slurries, or finely divided solids are mixed with finely divided glassformers (silica, alumina, soda, etc.) and injected directly into the plume of a non-transferred arc plasma torch. The extremely high temperatures and heat transfer rates makes it possible to convert the waste-glassformer mixture into a fully vitrified molten glass product in a matter of milliseconds. The molten product may then be collected in a crucible for casting into final wasteform geometry, quenching in water, or further holding time to improve homogeneity and eliminate bubbles.
McLaughlin, David F. (Oakmont, PA); Dighe, Shyam V. (North Huntingdon, PA); Gass, William R. (Plum Boro, PA)
Atmospheric Pressure Low Current Plasma for Syngas Production from Alcohol
Abstract – Atmospheric pressure low current arc discharge between graphite electrodes with conical geometry in liquid ethanol/water mixture was investigated. Syngas production was demonstrated over large experimental conditions. In this paper we focus on discharge aspects. It is shown from pictures that the behavior of low current arc discharge with consumable electrodes represents non-stationary plasma. The energetic properties of plasmas can be used to carry out many applications, particularly in discharge based systems. Recently, research interest focuses on the Non Thermal Plasma (NTP) treatment of hydrocarbons, alcohol, or biomass aimed to improve the yield of synthetic gas (syngas: H2+CO) production at low cost [1, 4]. Experiments were performed on a plasma reactor consisting of two graphite electrodes with conical shape
Ahmed Khacef; Khadija Arabi; Olivier Aubry; Jean Marie Cormier
Nitrogen Deposition Data Available
Nitrogen Deposition Data Available This data set, prepared by Elizabeth Holland and colleagues, contains data for wet and dry nitrogen-species deposition for the United States and...
Documentation of the operation of an arc-heated hydrogen atom source
A detailed description of the operation is given including establishment of an argon arc, changeover to hydrogen, and parameters of the hydrogen arc. A table of arc parameters for an 18 hour period is included. (GHT)
Way, K.R.; Yang, S.C.; Stwalley, W.C.
Plasma and ion beam processing at Los Alamos
Efforts are underway at Los Alamos National Laboratory to utilize plasma and intense ion beam science and technology of the processing of advanced materials. A major theme involves surface modification of materials, e.g., etching, deposition, alloying, and implantation. In this paper, we concentrate on two programs, plasma source ion implantation and high-intensity pulsed ion beam deposition.
Rej, D.J.; Davis, H.A.; Henins, I. [and others
What makes an electric welding arc perform its required function
The physics of direct current and alternating current welding arcs, the heat transfer of direct current welding arcs, the characteristics of dc welding and ac welding power supplies and recommendations for the procurement and maintenance of precision power supplies are discussed. (LCL)
Darwin: The Third DOE ARM TWP ARCS Site
Darwin: The Third DOE ARM TWP ARCS Site Darwin: The Third DOE ARM TWP ARCS Site W. E. Clements and L. Jones Los Alamos National Laboratory, Los Alamos, New Mexico T. Baldwin Special Services Unit Australian Bureau of Meteorology Melbourne, Australia K. Nitschke South Pacific Regional Environment Programme Apia, Samoa Introduction The U.S. Department of Energy's (DOE's) Atmospheric Radiation Measurement (ARM) Program began operations in its Tropical Western Pacific (TWP) locale in October 1996 when the first Atmospheric Radiation and Cloud Station (ARCS) began collecting data on Manus Island in Papua New Guinea (PNG). Two years later, in November 1998 a second ARCS began operations on the island of Nauru in the Central Pacific. Now a third ARCS has begun collecting data in Darwin, Australia. See Figure 1 for
Use of very-high-frequency plasmas to prepare a-Si:H-based triple-junction solar cells at high deposition rates: Annual technical status report, 11 March 1998--11 March 1999
This report describes work performed by Energy Conversion Devices, Inc. (ECD) during this phase of this subcontract. ECD researchers have made significant progress in advancing the very high frequency (VHF), high-rate technology. They demonstrated that 8.0% stable efficiencies can be achieved for a-Si:H cells whose i-layers are prepared at rates near 10 {angstrom}/s using the VHF technique. Presently, there is not a great difference in the performance of a-Si:H cells made using the VHF technique and i-layer deposition rates near 10 {angstrom}/s and that for cells made using the standard 13.56 MHz technique and rates near 1 {angstrom}/s in the same deposition system. In terms of the a-SiGe:H cells, researchers have completed a number of studies of devices with properties appropriate for middle-junction cells-that is, cells without Ag/ZnO back-reflectors having Voc values near 0.75V and Jsc values near 8.0 mA/cm{sup 2} when measured using AM1.5 light filtered using a 530-nm, low-band-pass filter. The stabilized proper ties for these cells prepared at i-layer rates near 10 {angstrom}/s are again similar to a-SiGe:H cells made using the same deposition hardware and the low-rate 13.56 MHz method. Establishing an initial 10.5% for a triple-junction cell whose i-layers are prepared at the high rates sets the baseline for ECD's future studies. The triple-junction cell degradation (10%--13%) with prolonged light soaking is similar to that regularly obtained for cells prepared at low i-layer deposition rates (1 {angstrom}/s). This is important because the use of high-rate methods to prepare i-layers typically leads to less-stable materials and cells. Increasing the buffer-layer deposition rate to 6 {angstrom}/s leads to nearly a 15-min decrease in the total deposition time, whereas the increase in the n-layer and p-layer deposition rates both decrease the total time by 5 and 5.8 min, respectively. Thus, besides the i-layer growth rates, increasing the buffer layer growth rate has the strongest effect on the deposition time of the triple-junction semiconductor structures.
Jones, S.J.; Liu, T.; Tsu, D.; Izu, M.
Plasma-enhanced and thermal atomic layer deposition of Al{sub 2}O{sub 3} using dimethylaluminum isopropoxide, [Al(CH{sub 3}){sub 2}({mu}-O{sup i}Pr)]{sub 2}, as an alternative aluminum precursor
The authors have been investigating the use of [Al(CH{sub 3}){sub 2}({mu}-O{sup i}Pr)]{sub 2} (DMAI) as an alternative Al precursor to [Al(CH{sub 3}){sub 3}] (TMA) for remote plasma-enhanced and thermal ALD over wide temperature ranges of 25-400 and 100-400 deg. C, respectively. The growth per cycle (GPC) obtained using in situ spectroscopic ellipsometry for plasma-enhanced ALD was 0.7-0.9 A/cycle, generally lower than the >0.9 A/cycle afforded by TMA. In contrast, the thermal process gave a higher GPC than TMA above 250 deg. C, but below this temperature, the GPC decreased rapidly with decreasing temperature. Quadrupole mass spectrometry data confirmed that both CH{sub 4} and HO{sup i}Pr were formed during the DMAI dose for both the plasma-enhanced and thermal processes. CH{sub 4} and HO{sup i}Pr were also formed during the H{sub 2}O dose but combustion-like products (CO{sub 2} and H{sub 2}O) were observed during the O{sub 2} plasma dose. Rutherford backscattering spectrometry showed that, for temperatures >100 deg. C and >200 deg. C for plasma-enhanced and thermal ALD, respectively, films from DMAI had an O/Al ratio of 1.5-1.6, a H content of {approx}5 at. % and mass densities of 2.7-3.0 g cm{sup -3}. The film compositions afforded from DMAI were comparable to those from TMA at deposition temperatures {>=}150 deg. C At lower temperatures, there were differences in O, H, and C incorporation. 30 nm thick Al{sub 2}O{sub 3} films from the plasma-enhanced ALD of DMAI were found to passivate n- and p-type Si floatzone wafers ({approx}3.5 and {approx}2 {Omega} cm, respectively) with effective carrier lifetimes comparable to those obtained using TMA. Surface recombination velocities of < 3 and < 6 cm s{sup -1} were obtained for the n- and p-type Si, respectively. Using these results, the film properties obtained using DMAI and TMA are compared and the mechanisms for the plasma-enhanced and thermal ALD using DMAI are discussed.
Potts, Stephen E.; Dingemans, Gijs; Lachaud, Christophe; Kessels, W. M. M. [Department of Applied Physics, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven (Netherlands); Air Liquide Research and Development, 1 Chemin de la Porte des Loges, BP 126, 78345 Jouy-en-Josas (France); Department of Applied Physics, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven (Netherlands)
An arc flash is the result of a rapid release of energy due to an arcing fault between
- Standard for Electrical Safety in the Workplace requires that a flash hazard analysis be conductedAn arc flash is the result of a rapid release of energy due to an arcing fault between conductors. The conductive material usually burns away from the intense heat. If conditions are right, the flow of energy can
Manual gas tungsten arc (dc) and semiautomatic gas metal arc welding of 6XXX aluminum. Welding procedure specification
Procedure WPS-1009 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for manual gas tungsten arc (DC) and semiautomatic gas metal arc (DC) welding of aluminum alloys 6061 and 6063 (P-23), in thickness range 0.187 to 2 in.; filler metal is ER4043 (F-23); shielding gases are helium (GTAW) and argon (GMAW).
Wodtke, C.H.; Frizzell, D.R.; Plunkett, W.A.
Waste Heat Recovery – Submerged Arc Furnaces (SAF)
Submerged Arc Furnaces are used to produce high temperature alloys. These furnaces typically run at 3000°F using high voltage electricity along with metallurgical carbon to reduce metal oxides to pure elemental form. The process as currently designed consumes power and fuel that yields an energy efficiency of approximately 40% (Total Btu's required to reduce to elemental form/ Btu Input). The vast majority of heat is lost to the atmosphere or cooling water system. The furnaces can be modified to recover this heat and convert it to power. The system will then reduce the amount of purchased power by approximately 25% without any additional use of fuel. The cost of this power is virtually unchanged over the life of the project because of the use of capital to displace fuel consumed from the purchased power source.
O'Brien, T.
Integration of Predicted Atmospheric Contaminant Plumes into ArcView GIS
The Savannah River National Laboratory (SRNL) plays a key role in emergency response scenarios in which there may be a release of atmospheric chemical or radiological contamination at the DOE's Savannah River Site (SRS). Meteorologists at SRNL use a variety of tools to predict the path of the plume and levels of contamination along the path. These predictions are used to guide field teams that take sample measurements for verification. Integration of these predicted plumes as well as field measurements into existing Geographic Information System (GIS) interactive maps provides key additional information for decision makers during an emergency. In addition, having this information in GIS format facilitates sharing the information with other agencies that use GIS. In order to be useful during an emergency, an application for converting predictions or measurements into GIS format must be automated and simple to use. Thus, a key design goal in developing such applications is ease of use. Simple menu selections and intuitive forms with graphical user interfaces are used to accomplish this goal. Applications have been written to convert two different predictive code results into ArcView GIS. Meteorologists at SRNL use the Puff/Plume code, which is tied to real-time wind data, to predict the direction and spread of the atmospheric plume for early assessment. The calculated circular puffs are converted into an ArcView polygon shapefile with attributes for predicted time, dose, and radius of the puff. The meteorologists use the more sophisticated Lagrangian Particle Dispersion Model (LPDM) to predict particle dispersion and deposition. The calculational grid is brought into ArcView as a point shapefile and then interpolated to ARC GRID format using Spatial Analyst. This GRID can then be contoured into a line shapefile, which is easily shared with other agencies. The deposition grid is also automatically contoured for values that correspond to FDA Derived Intervention Levels for beef, produce, and dairy products. Decision makers at SRS routinely use these predicted plumes to direct field teams. In the case of a strong release, this information can be used to decide whether to evacuate a particular area. Having this information in GIS format may aid the decision maker because other infrastructure information can be overlaid with geographic reference.
Koffman, Larry D.
Plasma treatment advantages for textiles
The textile industry is searching for innovative production techniques to improve the product quality, as well as society requires new finishing techniques working in environmental respect. Plasma surface treatments show distinct advantages, because they are able to modify the surface properties of inert materials, sometimes with environment friendly devices. For fabrics, cold plasma treatments require the development of reliable and large systems. Such systems are now existing and the use of plasma physics in industrial problems is rapidly increasing. On textile surfaces, three main effects can be obtained depending on the treatment conditions: the cleaning effect, the increase of microroughness (anti-pilling finishing of wool) and the production of radicals to obtain hydrophilic surfaces. Plasma polymerisation, that is the deposition of solid polymeric materials with desired properties on textile substrates, is under development. The advantage of such plasma treatments is that the modification turns out to ...
Sparavigna, Amelia
Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: Circuitry and mechanical design
A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 {mu}s. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.
Kia, Kaveh Kazemi [Department of Electrical and Computer Engineering, Islamic Azad University of Bonab, Bonab (Iran, Islamic Republic of); Bonabi, Fahimeh [Department of Engineering, Islamic Azad University of Bonab, Bonab (Iran, Islamic Republic of)
Optical fiber imaging for high speed plasma motion diagnostics: Applied to low voltage circuit breakers
An integrated portable measurement system is described for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. An array of optical fibers allows the formation of low spatial resolution images, with a maximum capture rate of 1x10{sup 6} images per second (1 MHz), with 8 bit intensity resolution. Novel software techniques are reported to allow imaging of the arc; and to measure arc trajectories. Results are presented on high current (2 kA) discharge events in a model test fixture and on the application to a commercial low voltage circuit breaker.
McBride, J. W. [School of Engineering Sciences, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Balestrero, A.; Tribulato, G. [ABB SACE DIVISION, ABB S.p.A., Via Baioni, Bergamo 35 IT-24123 (Italy); Ghezzi, L. [ABB SACE DIVISION, ABB S.p.A., Viale dell'Industria, Vittuone (MI)18 IT-20010 (Italy); Cross, K. J. [Taicaan Ltd., 2 Venture Road, Southampton Science Park, Southampton, Hampshire SO16 7NP (United Kingdom)
Welding and Repair Technology Center: Gas Metal Arc Welding Lessons
Modern gas metal arc welding (GMAW) systems no longer operate with a symmetric, fixed pulse. The new systems have closed-loop feedback and are waveform-controlled systems that vary the arc characteristics hundreds of times per second to stabilize the arc. The main advantage of these systems is the ease of operation when manual applications are required or out-of-position welding is applied. The systems allow flexibility in the stand-off distance (contact tip to work distance) while maintaining an ...
Mechanism and kinetics of H{sub 2}S-CO{sub 2} mixture dissociation in plasma of a microwave-discharge
Several experimental and theoretical investigations of plasma-chemical H{sub 2}S dissociation have addressed the effects of different gas compositions and various types of discharges (such as microwave, radio-frequency, arc, and glidarc discharges). There are two primary reasons for these investigations: (1) the plasma-chemical process recovers both hydrogen (a valuable chemical reagent) and sulfur from H{sub 2}S (as in the conventional Claus process), and (2) plasmas can be used for selectively decomposing H{sub 2}S in air and other exhaust gases for environmental-control purposes. These studies have shown that, in plasmas with strong centrifugal force fields, H{sub 2}S can be dissociated with high specific rates and low specific energies of dissociation (0.8-1.0 eV/molecule). Furthermore, acid gases from both natural deposits and those produced in industrial processes often contain significant amounts of CO{sub 2} in addition to H{sub 2}S. Unfortunately, CO{sub 2}can have substantial, negative impacts on H{sub 2}S dissociation. In particular, CO{sub 2} can significantly increase the process energy consumption and affect by-product composition. However, until this study, the influence of CO{sub 2} on the plasma-chemical dissociation of H{sub 2}S has not been studied in detail. This study presents the results of a theoretical analysis of an experimental determination of the CO{sub 2} effects over a wide range of CO{sub 2} concentrations. This analysis identified the primary chemical reaction mechanism and the kinetics for the plasma-chemical dissociation of H{sub 2}S, including the generation of two undesirable by-products, SO{sub 2} and COS.
Potapkin, B.V.; Strelkova, M.I.; Fridman, A.A. [RRC Kurchatov Institute, Moscow (Russian Federation)] [and others
Fundamental studies of defect generation in amorphous silicon alloys grown by remote plasma-enhanced chemical-vapor deposition (Remote PECVD). Annual subcontract report, 1 September 1990--31 August 1991
We demonstrated that the remote PECVD process can be used to deposit heavily doped n-type and p-type a-Si:H thin films. We optimized conditions for depositing undoped, near-intrinsic and heavily doped thin films of {mu}c(microcrystalline)-Si by remote PECVD. We extended the remote PECVD process to the deposition of undoped and doped a-Si,C:H and {mu}c-Si,C alloy films. We analyzed transport data for the dark conductivity in undoped and doped a-Si:H, a-Si,C:H, {mu}c-Si and {mu}c-Si,C films. We studied the properties of doped a-Si:H and {mu}c-Si in MOS capacitors using {approximately}10 {Omega}-cm p-type crystalline substrates and thermally grown Si0{sub 2} dielectric layers. We collaborated with a group at RWTH in Aachen, Germany, and studied the contributions of process induced defect states to the recombination of photogenerated electron pairs. We applied a tight-binding model to Si-Bethe lattice structures to investigate the effects of bond angle, and dihedral angle disorder. We used ab initio and empirical calculations to study non-random bonding arrangements in a-Si,O:H and doped a-Si:H films.
Lucovsky, G.; Nemanich, R.J.; Bernholc, J.; Whitten, J.; Wang, C.; Davidson, B.; Williams, M.; Lee, D.; Bjorkman, C.; Jing, Z. [North Carolina State Univ., Raleigh, NC (United States)
Dynamic modeling of plasma-vapor interactions during plasma disruptions
Intense deposition of energy in short times on fusion reactor components during a plasma disruption may cause severe surface erosion due to ablation of these components. The exact amount of the eroded material is very important to the reactor design and its lifetime. During the plasma deposition, the vaporized wall material will interact with the incoming plasma particles and may shield the rest of the wall from damage. The vapor shielding may then prolong the lifetime of these components and increase the reactor duty cycle. To correctly evaluate the impact of vapor shielding effect a comprehensive model is developed. In this model the dynamic slowing down of the plasma particles, both ions and electrons, with the eroded wall material is established. Different interaction processes between the plasma particles and the ablated material is included. The generated photons radiation source and the transport of this radiation through the vapor to the wall is modeled. Recent experimental data on disruptions is analyzed and compared with model predictions. Vapor shielding may be effective in reducing the overall erosion rate for certain plasma disruption parameters and conditions.
Hassanein, A.; Ehst, D.A.
Back arc extension and collision: An experimental approach of the tectonics of Asia
arc basins (Japan Sea, Okinawa Trough, South China Sea) and continental grabens (North China grabens
DOE Solar Decathlon: News Blog » SCI-Arc/Caltech
SCI-Arc/Caltech SCI-Arc/Caltech Below you will find Solar Decathlon news from the SCI-Arc/Caltech archive, sorted by date. CHIP House Takes Design to Different Heights (Literally) Friday, May 13, 2011 By April Saylor Editor's Note: This entry has been cross-posted from DOE's Energy Blog. In honor of the U.S. Department of Energy Solar Decathlon-which challenges 20 collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive-we are profiling each of the 20 teams participating in the competition. The students from the Southern California Institute of Architecture and California Institute of Technology, otherwise known as the SCI-Arc/Caltech team, have teamed up to take an interesting approach to the design of their
Capabilities of the ARCS Instrument - ORNL Neutron Sciences
Capabilities of the ARCS Instrument Capabilities of the ARCS Instrument ARCS Overview The wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source (SNS) is optimized to provide a high neutron flux at the sample position with a large solid angle of detector coverage. The instrument incorporates modern neutron instrumentation, such as an elliptically focused neutron guide, high speed magnetic bearing choppers, and a massive array of 3He linear position sensitive detectors. Novel features of the spectrometer include the use of a large gate valve between the sample and detector vacuum chambers and the placement of the detectors within the vacuum, both of which provide a window-free final flight path to minimize background scattering while allowing rapid changing of the sample and
Exhaust-gas measurements from NASAs HYMETS arc jet.
Arc-jet wind tunnels produce conditions simulating high-altitude hypersonic flight such as occurs upon entry of space craft into planetary atmospheres. They have traditionally been used to study flight in Earth's atmosphere, which consists mostly of nitrogen and oxygen. NASA is presently using arc jets to study entry into Mars' atmosphere, which consists of carbon dioxide and nitrogen. In both cases, a wide variety of chemical reactions take place among the gas constituents and with test articles placed in the flow. In support of those studies, we made measurements using a residual gas analyzer (RGA) that sampled the exhaust stream of a NASA arc jet. The experiments were conducted at the HYMETS arc jet (Hypersonic Materials Environmental Test System) located at the NASA Langley Research Center, Hampton, VA. This report describes our RGA measurements, which are intended to be used for model validation in combination with similar measurements on other systems.
Miller, Paul Albert
Application of Vacuum Deposition Methods to Solid Oxide Fuel Cells
The application of vacuum deposition techniques to the fabrication of solid oxide fuel cell materials and structures are reviewed, focusing on magnetron sputtering, vacuum plasma methods, laser ablation, and electrochemical vapor deposition. A description of each method and examples of use to produce electrolyte, electrode, and/or electrical interconnects are given. Generally high equipment costs and relatively low deposition rates have limited the use of vacuum deposition methods in solid oxide fuel cell manufacture, with a few notable exceptions. Vacuum methods are particularly promising in the fabrication of micro fuel cells, where thin films of high quality and unusual configuration are desired.
Pederson, Larry R.; Singh, Prabhakar; Zhou, Xiao Dong
Arc Flash Phase II Work Practices Survey Report
The Arc Flash Phase II Work Practices Survey was conducted as part of an EPRI project aimed at helping utilities understand and prepare for changing National Electrical Safety Code (NESC) and Occupational Safety and Safety Administration (OSHA) arc flash regulations. These changes can have significant implications for utility work practices, protective schema, and personal protection. The results of this survey are summarized in this report. The Phase II Survey is the second of two surveys EPRI has condu...
Laser assisted non-consumable arc welding process development
The employment of Laser Beam Welding (LBW) for many traditional arc welding applications is often limited by the inability of LBW to compensate for variations in the weld joint gap. This limitation is associated with fluctuations in the energy transfer efficiency along the weld joint. Since coupling of the laser beam to the workpiece is dependent on the maintenance of a stable absorption keyhole, perturbations to the weld pool can lead to decreased energy transfer and resultant weld defects. Because energy transfer in arc welding does not similarly depend on weld pool geometry, it is expected that combining these two processes together will lead to an enhanced fusion welding process that exhibits the advantages of both arc welding and LBW. Laser assisted non-consumable arc welds have been made on thin section aluminum. The welds combine the advantages of arc welding and laser welding, with enhanced penetration and fusion zone size. The use of a pulsed Nd:YAG laser with the combined process appears to be advantageous since this laser is effective in removing the aluminum oxide and thereby allowing operation with the tungsten electrode negative. The arc appears to increase the size of the weld and also to mitigate hot cracking tendencies that are common with the pulsed Nd:YAG laser.
Fuerschach, P.W.; Hooper, F.M.
Treatment studies of plutonium-bearing INEEL waste surrogates in a bench-scale arc furnace
Since 1989, the Subsurface Disposal Area (SDA) at the Idaho National Environmental and Engineering Laboratory (INEEL) has been included on the National Priority List for remediation. Arc- and plasma-heated furnaces are being considered for converting the radioactive mixed waste buried in the SDA to a stabilized-vitreous form. Nonradioactive, surrogate SDA wastes have been melted during tests in these types of furnaces, but data are needed on the behavior of transuranic (TRU) constituents, primarily plutonium, during thermal treatment. To begin collecting this data, plutonium-spiked SDA surrogates were processed in a bench-scale arc furnace to quantify the fate of the plutonium and other hazardous and nonhazardous metals. Test conditions included elevating the organic, lead, chloride, and sodium contents of the surrogates. Blends having higher organic contents caused furnace power levels to fluctuate. An organic content corresponding to 50% INEEL soil in a soil-waste blend was the highest achievable before power fluctuations made operating conditions unacceptable. The glass, metal, and off-gas solids produced from each surrogate blend tested were analyzed for elemental (including plutonium) content and the partitioning of each element to the corresponding phase was calculated.
Freeman, C.J.
Plasma Technology
Table 3Â Â Â Deposition rates for various compounds...Table 3 Deposition rates for various compounds Compound Deposition rate (D), 10 8 Ă? gm/cm 2 /min D/D 0 Hexamethyldisiloxane 233 = D 0 1.00 Acrylic acid 28 0.12 Styrene 173 0.74 Tetramethyldisiloxane 191 0.82 Divinyltetramethyldisiloxane 641 2.75 Ethylene 42 0.18 Benzene 110 0.47 Source: Ref 49...
J. Plasma Fusion Res. SERIES, Vol. 8 (2009) EFFECTS OF GAS PRESSURE AND DISCHARGE POWER ON ELECTRICAL AND OPTICAL PROPERTIES OF ZNO:AL THIN FILM DEPOSITED ON POLYMER SUBSTRATE
In this paper aluminium-doped zinc oxide(ZnO:Al) conducting layer was deposited on polyethylene terephthalate(PET) substrate by r. f. magnetron sputtering method. The effects of gas pressure and r. f. sputtering power on the structural and electrical properties of ZnO:Al thin film were investigated experimentally. The results show that the resistivity of the film was strongly influenced by the gas pressure and r. f. sputtering power. The electrical properties were improved with increase in sputtering power and gas pressure up to 180W and 5mTorr. However excessive supply of sputtering power limits the growth of crystalline grains due to too high deposition rate and may cause a degradation of the preferred orientation, giving high electrical resistivity. The lowest resistivity and optical transmittance were ~1.1×10-3 ?-cm and ~85%, respectively and were obtained under the experimental conditions of 180W of sputtering power and 5mTorr of gas pressure.
Dong-joo Kwak; Byung-wook Park; Youl-moon Sung; Min-woo Park
Stability of very-high pressure arc discharges against perturbations of the electron temperature
We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.
Benilov, M. S. [Departamento de Fisica, Ciencias Exactas e Engenharia, Universidade da Madeira, Largo do Municipio, Funchal 9000 (Portugal); Hechtfischer, U. [Philips Lighting, BU Automotive Lamps, Technology, Philipsstrasse 8, Aachen 52068 (Germany)
Plasma generators, reactor systems and related methods
A plasma generator, reactor and associated systems and methods are provided in accordance with the present invention. A plasma reactor may include multiple sections or modules which are removably coupled together to form a chamber. Associated with each section is an electrode set including three electrodes with each electrode being coupled to a single phase of a three-phase alternating current (AC) power supply. The electrodes are disposed about a longitudinal centerline of the chamber and are arranged to provide and extended arc and generate an extended body of plasma. The electrodes are displaceable relative to the longitudinal centerline of the chamber. A control system may be utilized so as to automatically displace the electrodes and define an electrode gap responsive to measure voltage or current levels of the associated power supply.
Kong, Peter C. (Idaho Falls, ID); Pink, Robert J. (Pocatello, ID); Lee, James E. (Idaho Falls, ID)
Deposition Diagnostics for Next-step Devices
The scale-up of deposition in next-step devices such as ITER will pose new diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a new challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons - however diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect surface particles on remote surfaces was commissioned on NSTX.
C.H. Skinner; A.L. Roquemore; the NSTX team; A. Bader; W.R. Wampler
Plasma valve
A plasma valve includes a confinement channel and primary anode and cathode disposed therein. An ignition cathode is disposed adjacent the primary cathode. Power supplies are joined to the cathodes and anode for rapidly igniting and maintaining a plasma in the channel for preventing leakage of atmospheric pressure through the channel.
Hershcovitch, Ady (Mount Sinai, NY); Sharma, Sushil (Hinsdale, IL); Noonan, John (Naperville, IL); Rotela, Elbio (Clarendon Hills, IL); Khounsary, Ali (Hinsdale, IL)
BS>A method is given for ion cyclotron resonance heatthg of a magnetically confined plasma by an applied radio-frequency field. In accordance with the invention, the radiofrequency energy is transferred to the plasma without the usual attendent self-shielding effect of plasma polarlzatlon, whereby the energy transfer is accomplished with superior efficiency. More explicitly, the invention includes means for applying a radio-frequency electric field radially to an end of a plasma column confined in a magnetic mirror field configuration. The radio-frequency field propagates hydromagnetic waves axially through the column with the waves diminishing in an intermediate region of the column at ion cyclotron resonance with the fleld frequency. In such region the wave energy is converted by viscous damping to rotational energy of the plasma ions. (AEC)
Furth, H.P.; Chambers, E.S.
A device is described for establishing and maintaining a high-energy, rotational plasma for use as a fast discharge capacitor. A disc-shaped, current- conducting plasma is formed in an axinl magnetic field and a crossed electric field, thereby creating rotational kinetic enengy in the plasma. Such energy stored in the rotation of the plasma disc is substantial and is convertible tc electrical energy by generator action in an output line electrically coupled to the plasma volume. Means are then provided for discharging the electrical energy into an external circuit coupled to the output line to produce a very large pulse having an extremely rapid rise time in the waveform thereof. (AE C)
Baker, W.R.
PROTECT YOUR BANKING INFORMATION: PROTECT YOUR BANKING INFORMATION: DO NOT complete this form until you are ready to submit it to the Payroll Department. DIRECT DEPOSIT REQUEST Directions: 1. Provide required information neatly, legibly; 2. If Checking Account Direct Deposit, include a voided check. a. DO NOT submit a deposit slip! 3. If Savings Account Direct Deposit, include a copy of savings card. 4. Sign this form; 5. Inter-office mail it to Craft Payroll at "P238." DIRECT DEPOSITION AUTHORIZATION I hereby authorize Los Alamos National Laboratory, hereinafter called The Laboratory, to initiate credit entries and, if necessary, debit entries and adjustments for any credit entries in error to my account listed on this form. If deposit is for:
Apparatus and process for deposition of hard carbon films
A process and an apparatus for depositing thin, amorphous carbon films having extreme hardness on a substrate is described. An enclosed chamber maintained at less than atmospheric pressure houses the substrate and plasma producing elements. A first electrode is comprised of a cavity enclosed within an RF coil which excites the plasma. A substrate located on a second electrode is excited by radio frequency power applied to the substrate. A magnetic field confines the plasma produced by the first electrode to the area away from the walls of the chamber and focuses the plasma onto the substrate thereby yielding film deposits having higher purity and having more rapid buildup than other methods of the prior art.
Nyaiesh, Ali R. (Menlo Park, CA); Garwin, Edward L. (Los Altos, CA)
Advanced RenewableEnergy Company ARC Energy | Open Energy Information
Advanced RenewableEnergy Company ARC Energy Advanced RenewableEnergy Company ARC Energy Jump to: navigation, search Name Advanced RenewableEnergy Company (ARC Energy) Place Nashua, New Hampshire Product New Hampshire-based stealth mode LED substrate manufacture equipment provider which aims to lower the cost of LEDs. Coordinates 42.758365°, -71.464209° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.758365,"lon":-71.464209,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
ArcSafe® with Pulsed Arrested Spark Discharge
ArcSafe® ArcSafe® with Pulsed Arrested Spark Discharge 2007 R&D 100 Award Entry Form ArcSafe® with Pulsed Arrested Spark Discharge Joint Submitters Submitting Organization Sandia National Laboratories PO Box 5800, MS 1181 Albuquerque, NM 87185-1181 USA Larry Schneider Phone: (505) 845-7135 Fax: (505) 845-7685 Email: email@example.com AFFIRMATION: I affirm that all information submitted as a part of, or supplemental to, this entry is a fair and accurate represen- tation of this product. (Signature)______________________________________ Astronics-Advanced Electronic Systems, Inc. 9845 Willows Rd NE City: Redmond State: WA Zip/Postal: 98052-2540 USA Contact Name: Michael Ballas, Program Manager Phone: (425) 895-4304 Fax: (425)702.4930 Email: email@example.com
Muon Acceleration with RLA and Non-scaling FFAG Arcs
Recirculating Linear Accelerators (RLA) are the most likely means to achieve the rapid acceleration of shortlived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. In this paper, we present a novel return-arc optics design based on a Non Scaling Fixed Field Alternating Gradient (NS-FFAG) lattice that allows 5 and 9 GeV/c muons of both charges to be transported in the same string of magnets. The return arcs are made up of super cells with each super cell consisting of three triplets. By employing combined function magnets with dipole, quadrupole, sextupole and octupole magnetic field components, each super cell is designed to be achromatic and to have zero initial and final periodic orbit offsets for both 5 and 9 GeV/c muon momenta. This solution would reduce the number of arcs by a factor of 2, simplifying the overall design.
Vasiliy Morozov,Alex Bogacz,Dejan Trbojevic
High-bandwidth continuous-flow arc furnace
A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics. 4 figs.
Hardt, D.E.; Lee, S.G.
Measurment of Depositing and Bombarding Species Involved in the Plasma Production of Amorphous Silicon and Silicon/Germanium Solar Cells: Annual Technical Report, 1 June 2002 - 31 May 2005
The objective of this study is to measure the molecular species that lead to the growth of hydrogenated amorphous silicon (a-Si:H) and microcrystalline silicon (..mu..c-Si) photovoltaic (PV) devices from RF discharges. Neutral radicals produce most of the film growth during this PV-device production, and, by implication, radicals primarily determine the device structure and electrical characteristics. The most important feature of the present experiment is thus the measurement of neutral-radical fluxes to the substrate. Additional depositing species that can influence film properties are positive ions and silicon-based particles produced by the discharge; we also measure these positive-ion species here. Some studies have already measured some of these radical and positive-ion species in silane and silane/argon discharges, but not for discharge conditions similar to those used to produce most photovoltaic devices. Our objective is to measure all of these species for conditions typically used for device production. In particular, we have studied 13.6 MHz-excited discharges in pure silane and silane/hydrogen vapors.
Gallagher, A.; Rozsa, K.; Horvath, P.; Kujundcik, D.
Plasma plume effects on the conductivity of amorphous-LaAlO{sub 3}/SrTiO{sub 3} interfaces grown by pulsed laser deposition in O{sub 2} and Ar
Amorphous-LaAlO{sub 3}/SrTiO{sub 3} interfaces exhibit metallic conductivity similar to those found for the extensively studied crystalline-LaAlO{sub 3}/SrTiO{sub 3} interfaces. Here, we investigate the conductivity of the amorphous-LaAlO{sub 3}/SrTiO{sub 3} interfaces grown in different pressures of O{sub 2} and Ar background gases. During the deposition, the LaAlO{sub 3} ablation plume is also studied, in situ, by fast photography and space-resolved optical emission spectroscopy. An interesting correlation between interfacial conductivity and kinetic energy of the Al atoms in the plume is observed: to assure conducting interfaces of amorphous-LaAlO{sub 3}/SrTiO{sub 3}, the kinetic energy of Al should be higher than 1 eV. Our findings add further insights on mechanisms leading to interfacial conductivity in SrTiO{sub 3}-based oxide heterostructures.
Sambri, A.; Amoruso, S.; Bruzzese, R.; Wang, X. [CNR-SPIN and Dipartimento di Scienze Fisiche, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80125 Napoli (Italy); Cristensen, D. V.; Trier, F.; Chen, Y. Z.; Pryds, N. [Department of Energy Conversion and Storage, Risoe Campus, Technical University of Denmark, DK-4000 Roskilde (Denmark)
Integrated models for plasma/material interaction during loss of plasma confinement.
A comprehensive computer package, High Energy Interaction with General Heterogeneous Target Systems (HEIGHTS), has been developed to evaluate the damage incurred on plasma-facing materials during loss of plasma confinement. The HEIGHTS package consists of several integrated computer models that follow the start of a plasma disruption at the scrape-off layer (SOL) through the transport of the eroded debris and splashed target materials to nearby locations as a result of the energy deposited. The package includes new models to study turbulent plasma behavior in the SOL and predicts the plasma parameters and conditions at the divertor plate. Full two-dimensional comprehensive radiation magnetohydrodynamic models are coupled with target thermodynamics and liquid hydrodynamics to evaluate the integrated response of plasma-facing materials. A brief description of the HEIGHTS package and its capabilities are given in this work with emphasis on turbulent plasma behavior in the SOL during disruptions.
Hassanein, A.
An ion source based on the cathodic arc
This invention is comprised of a cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated. An array of electrically isolated rings positioned in the source serves the duel purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles.
Interaction between a high density-low temperature plasma and a frozen hydrogen pellet in a railgun injector
A model has been developed which describes the ablation process of frozen hydrogen pellets in an electromagnetic railgun. The model incorporates the neutral gas shielding model in which the pellet surface is heated by incident electrons from the plasma arc. The heated surface then ablates, forming a neutral cloud which attenuates the incoming electrons. The energy lost in the cloud by the electrons heats the ablatant material as it flows into the plasma arc. Under steady-state conditions, a scaling law for the ablation rate was derived as a function of plasma-arc temperature and density. In addition, flow conditions and the criteria for the existence of a steady-state solution were formulated and subsequently examined under simplifying assumptions. Comparison with experimentally observed ablation rates shows good qualitative agreement.
Grapperhaus, M.J. [Illinois Univ., Urbana, IL (United States)
Plasma momentum meter for momentum flux measurements
Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer--a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10.sup.-5 to 10.sup.3 N) accompanied by high heat fluxes which are transmitted by energetic particles with 10's of eV of kinetic energy in a intense magnetic field and pulsed plasma environment.
Zonca, Fulvio (Rome, IT); Cohen, Samuel A. (Hopewell, NJ); Bennett, Timothy (Princeton, NJ); Timberlake, John R. (Allentown, NJ)
Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer - a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10{sup {minus}5} to 10{sup 3} N) accompanied by high heat fluxes which are transmitted by energetic particles with 10`s of eV of kinetic energy in an intense magnetic field and pulsed plasma environment.
Zonca, F.; Cohen, S.A.; Bennett, T.; Timberlake, J.R.
Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer - a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10[sup [minus]5] to 10[sup 3] N) accompanied by high heat fluxes which are transmitted by energetic particles with 10's of eV of kinetic energy in an intense magnetic field and pulsed plasma environment.
Radionuclide deposition control
The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition.
Brehm, William F. (Richland, WA); McGuire, Joseph C. (Richland, WA)
Design of a High-Throughput Plasma-Processing System
Sandia National Laboratories has demonstrated significant performance gains in crystalline silicon solar cell technology through the use of plasma-processing for the deposition of silicon nitride by Plasma Enhanced Chemical Vapor Deposition (PECVD), plasma-hydrogenation of the nitride layer, and reactive-ion etching of the silicon surface prior to the deposition to decrease the reflectivity of the surface. One of the major problems of implementing plasma processing into a cell production line is the batch configuration and/or low throughput of the systems currently available. This report describes the concept of a new in-line plasma processing system that could meet the industrial requirements for a high-throughput and cost effective solution for mass production of solar cells.
Darkazalli, Ghazi; Matthei, Keith; Ruby, Douglas S.
Plasma Nitrocarburizing
...heat pollution Reduced processing times Reduced energy consumption Reduced treatment gas consumption Industrial plasma nitrocarburizing processing modules contain: Vacuum furnace Vacuum system Gas supply with gas mixing and pressure control system Electric power supply unit Microprocessor control unit...
A Space-Charge-Neutralizing Plasma for Beam Drift Compression
Simultaneous radial focusing and longitudinal compression of intense ion beams are being studied to heat matter to the warm dense matter, or strongly coupled plasma regime. Higher compression ratios can be achieved if the beam compression takes place in a plasma-filled drift region in which the space-charge forces of the ion beam are neutralized. Recently, a system of four cathodic arc plasma sources has been fabricated and the axial plasma density has been measured. A movable plasma probe array has been developed to measure the radial and axial plasma distribution inside and outside of a {approx} 10 cm long final focus solenoid (FFS). Measured data show that the plasma forms a thin column of diameter {approx} 5 mm along the solenoid axis when the FFS is powered with an 8T field. Measured plasma density of {ge} 1 x 10{sup 13} cm{sup -3} meets the challenge of n{sub p}/Zn{sub b} > 1, where n{sub p} and n{sub b} are the plasma and ion beam density, respectively, and Z is the mean ion charge state of the plasma ions.
Roy, P.K.; Seidl, P.A.; Anders, A.; Bieniosek, F.M.; Coleman, J.E.; Gilson, E.P.; Greenway, W.; Grote, D.P.; Jung, J.Y.; Leitner, M.; Lidia, S.M.; Logan, B.G.; Sefkow, A.B.; Waldron, W.L.; Welch, D.R.
Rates of tectonic and magmatic processes in the North Cascades continental magmatic arc
Continental magmatic arcs are among the most dynamic. geologic systems, and documentation of the magmatic, thermal, and tectonic evolution of arcs is essential for understanding the processes of magma generation, ascent ...
Matzel, Jennifer E. Piontek, 1973-
dc-plasma-sprayed electronic-tube device
An electronic tube and associated circuitry which is produced by dc plasma arc spraying techniques is described. The process is carried out in a single step automated process whereby both active and passive devices are produced at very low cost. The circuitry is extremely reliable and is capable of functioning in both high radiation and high temperature environments. The size of the electronic tubes produced are more than an order of magnitude smaller than conventional electronic tubes.
Meek, T.T.
Plasma chemistry in wire chambers
The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed.
Wise, J.
Constricted glow discharge plasma source
A constricted glow discharge chamber and method are disclosed. The polarity and geometry of the constricted glow discharge plasma source is set so that the contamination and energy of the ions discharged from the source are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The source is suitable for applying films of nitrides such as gallium nitride and oxides such as tungsten oxide and for enriching other substances in material surfaces such as oxygen and water vapor, which are difficult process as plasma in any known devices and methods. The source can also be used to assist the deposition of films such as metal films by providing low-energy ions such as argon ions.
Anders, Andre (Albany, CA); Anders, Simone (Albany, CA); Dickinson, Michael (San Leandro, CA); Rubin, Michael (Berkeley, CA); Newman, Nathan (Winnetka, IL)
An optimal coarse-grained arc consistency algorithm
The use of constraint propagation is the main feature of any constraint solver. It is thus of prime importance to manage the propagation in an efficient and effective fashion. There are two classes of propagation algorithms for general constraints: fine-grained ... Keywords: Arc consistency, Constraint networks, Constraint programming systems, Non-binary constraints, Path consistency
Christian Bessičre; Jean-Charles Régin; Roland H. C. Yap; Yuanlin Zhang
arc pyrolysis of methane at supersonic conditions, representative of conditions in the reformer is then reformed or cracked to produce hydrogen. The hy- drocarbon of choice is methane because of its highest material instead of as a fuel. Amongst various hydrogen production technologies,7 steam reformation
Texas at Arlington, University of
Modern Control Strategies for Vacuum Arc Remelting of Segregation ...
variable becomes too large, the arc will search for a less resistive path to ground ... process can enter a mode where T,, remains constant as g, opens. ... term (-20 minutes) averaging; however, this causes the system to be highly damped and.
Streamwise and spanwise plasma actuators for flow-induced cavity noise control
to manufacture and install. The simplicity and absence of any mechanical moving parts, for example, pump the flow field local to plasma actuators by electric discharges. The first one is the local heating of the airflow caused by arc filaments5 or direct cur- rent discharges:6,7 Heat energy is added
Huang, Xun
Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna
RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.
Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M. [LPP/ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Wooldridge, E. [EURATOM/CCFE Fusion Association, Culham Science Centre (United Kingdom)
Perspectives on Deposition Velocity
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Deposition Deposition Velocity ... Going down the rabbit hole to explain that sinking feeling Brian DiNunno, Ph.D. Project Enhancement Corporation June 6 th , 2012 Discussion Framework ď'— Development of the HSS Deposition Velocity Safety Bulletin ď'— Broader discussion of appropriate conservatism within dispersion modeling and DOE-STD-3009 DOE-STD-3009 Dose Comparison "General discussion is provided for source term calculation and dose estimation, as well as prescriptive guidance for the latter. The intent is that calculations be based on reasonably conservative estimates of the various input parameters." - DOE-STD-3009, Appendix A.3 DOE-STD-3009 Dispersion
SciTech Connect: "plasma science"
plasma science" Find plasma science" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced Ă— Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)
Studies of plasma transport
This report discusses the charge-coupled device camera and other plasma diagnostic equipment used to measure plasma density and other plasma properties. (LSP)
Malmberg, J.H.; O' Neil, T.M.; Driscoll, C.F.
A device for producing a confined high temperature plasma is described. In the device the concave inner surface of an outer annular electrode is disposed concentrically about and facing the convex outer face of an inner annular electrode across which electrodes a high potential is applied to produce an electric field there between. Means is provided to create a magnetic field perpendicular to the electric field and a gas is supplied at reduced pressure in the area therebetween. Upon application of the high potential, the gas between the electrodes is ionized, heated, and under the influence of the electric and magnetic fields there is produced a rotating annular plasma disk. The ionized plasma has high dielectric constant properties. The device is useful as a fast discharge rate capacitor, in controlled thermonuclear research, and other high temperature gas applications. (AEC)
Baker, W.R.; Brathenahl, A.; Furth, H.P.
The fractal nature of vacuum arc cathode spots
plasma-emitting) spot fragment will increase its area in time (~10-100 ns timescale) due to heat conduction,
BWR Fuel Deposit Evaluation
With zinc injection to BWR feedwater for plant radiation dose reduction, fuel deposits often contain significant amounts of zinc and the inner layers of deposits become more adherent to the cladding. Fuel surveillance programs have revealed thick tenacious crud with surface spallation at several plants. This project determined the chemical composition and morphological features of crud flake samples from Duane Arnold Cycle 17 and Browns Ferry 2 Cycle 12 and compared the data with those obtained from othe...
EMSL: Capabilities: Deposition and Microfabrication
Deposition and Microfabrication Deposition and Microfabrication Additional Information Meet the Deposition and Microfabrication Experts Related EMSL User Projects Deposition and Microfabrication Tools are Applied to all Science Themes Deposition and Microfabrication brochure Designed to augment research important to a variety of disciplines, EMSL's Deposition and Microfabrication Capability tackles serious scientific challenges from a microscopic perspective. From deposition instruments that emphasize oxide films and interfaces to a state-of-the-art microfabrication suite, EMSL has equipment to tailor surfaces, as diverse as single-crystal thin films or nanostructures, or create the microenvironments needed for direct experimentation at micron scales. Users benefit from coupling deposition and microfabrication applications
NSTX Plasma Response to Lithium Coated Divertor
NSTX experiments have explored lithium evaporated on a graphite divertor and other plasma facing components in both L- and H- mode confinement regimes heated by high-power neutral beams. Improvements in plasma performance have followed these lithium depositions, including a reduction and eventual elimination of the HeGDC time between discharges, reduced edge neutral density, reduced plasma density, particularly in the edge and the SOL, increased pedestal electron and ion temperature, improved energy confinement and the suppression of ELMs in the H-mode. However, with improvements in confinement and suppression of ELMs, there was a significant secular increase in the effective ion charge Zeff and the radiated power in H-mode plasmas as a result of increases in the carbon and medium-Z metallic impurities. Lithium itself remained at a very low level in the plasma core, <0.1%. Initial results are reported from operation with a Liquid Lithium Divertor (LLD) recently installed.
H.W. Kugel, M.G. Bell, J.P. Allain, R.E. Bell, S. Ding, S.P. Gerhardt, M.A. Jaworski, R. Kaita, J. Kallman, S.M. Kaye, B.P. LeBlanc, R. Maingi, R. Majeski, R. Maqueda, D.K. Mansfield, D. Mueller, R. Nygren, S.F. Paul, R. Raman, A.L. Roquemore, S.A. Sabbagh, H. Schneider, C.H. Skinner, V.A. Soukhanovskii, C.N. Taylor, J.R. Timberlak, W.R. Wampler, L.E. Zakharov, S.J. Zweben, and the NSTX Research Team
NSTX experiments have explored lithium evaporated on a graphite divertor and other plasma facing components in both L- and H- mode confinement regimes heated by high-power neutral beams. Improvements in plasma performance have followed these lithium depositions, including a reduction and eventual elimination of the HeGDC time between discharges, reduced edge neutral density, reduced plasma density, particularly in the edge and the SOL, increased pedestal electron and ion temperature, improved energy confinement and the suppression of ELMs in the H-mode. However, with improvements in confinement and suppression of ELMs, there was a significant secular increase in the effective ion charge Zeff and the radiated power in H-mode plasmas as a result of increases in the carbon and medium-Z metallic impurities. Lithium itself remained at a very low level in the plasma core, Lithium Divertor (LLD) recently installed.
Study on the Properties of Ionized Metal Plasma Methodology on Titanium
Ionized Metal Plasma (IMP) deposition was used in depositing metal interconnection of titanium metal film. Inductively coupled plasma (ICP) was attached to chamber wall where it creates an electromagnetic field, thus, ionizing the sputtered metal atoms from target. The film morphology was observed by scanning electron microscope (SEM). Acoustic measurement of titanium film thickness showed that there was a comparable result with film resistance measured by 4-point probe. Results show that higher plasma density would cause tensile properties on the film stress.
Leow, M. T. [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Infineon Technologies (Kulim) Sdn Bhd, Lot 10 and 11, Jalan Hi-Tech 7, Industrial Zone Phase 2, Kulim Hi-Tech Park, 09000, Kulim, Kedah Darul Aman (Malaysia); Hassan, Z. [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Lee, K. E.; Omar, G.; Lim, S. P.; Chan, C. F.; Siew, E. T.; Chuah, Z. M. [Infineon Technologies (Kulim) Sdn Bhd, Lot 10 and 11, Jalan Hi-Tech 7, Industrial Zone Phase 2, Kulim Hi-Tech Park, 09000, Kulim, Kedah Darul Aman (Malaysia)
PLASMA PHYSICS & RADIATION TECHNOLOGY Dutch Physical Society
-SiO2 nanocomposites for surface plasmon resonance- based red colored coatings A5 Electrostatic double). #12;A 4 Plasma deposition of multilayer Au-SiO2 nanocomposites for surface plasmon resonance- based of surface plasmon resonance- based deep colored coatings
Eindhoven, Technische Universiteit
Ultrashort pulse laser deposition of thin films
Short pulse PLD is a viable technique of producing high quality films with properties very close to that of crystalline diamond. The plasma generated using femtosecond lasers is composed of single atom ions with no clusters producing films with high Sp.sup.3 /Sp.sup.2 ratios. Using a high average power femtosecond laser system, the present invention dramatically increases deposition rates to up to 25 .mu.m/hr (which exceeds many CVD processes) while growing particulate-free films. In the present invention, deposition rates is a function of laser wavelength, laser fluence, laser spot size, and target/substrate separation. The relevant laser parameters are shown to ensure particulate-free growth, and characterizations of the films grown are made using several diagnostic techniques including electron energy loss spectroscopy (EELS) and Raman spectroscopy.
Perry, Michael D. (Livermore, CA); Banks, Paul S. (Livermore, CA); Stuart, Brent C. (Fremont, CA)
Dynamic behavior of plasma-facing materials during plasma instabilities in tokamak reactors
Damage to plasma-facing and nearby components due to plasma instabilities remains a major obstacle to a successful tokamak concept. The high energy deposited on facing materials during plasma instabilities can cause severe erosion, plasma contamination, and structural failure of these components. Erosion damage can take various forms such as surface vaporization, spallation, and liquid ejection of metallic materials. Comprehensive thermodynamic and radiation hydrodynamic codes have been developed, integrated, and used to evaluate the extent of various damage to plasma-facing and nearby components. The eroded and splashed materials will be transported and then redeposited elsewhere on other plasma-facing components. Detailed physics of plasma/solid-liquid/vapor interaction in a strong magnetic field have been developed, optimized, and implemented in a self-consistent model. The plasma energy deposited in the evolving divertor debris is quickly and intensely reradiated, which may cause severe erosion and melting of other nearby components. Factors that influence and reduce vapor-shielding efficiency such as vapor diffusion and turbulence are also discussed and evaluated.
Hassanein, A. [Argonne National Lab., IL (United States); Konkashbaev, I. [Troitsk Inst. for Innovation and Fusion Research (Russian Federation)
The effects of atmospheric pressure plasma on the synthesis of carbon nanotubes
In this study, we investigated the effects of atmospheric plasma on the synthesis of carbon nanotubes (CNTs) forests. Tall and high CNTs forests have been successfully grown on a large scale using a newly developed system called atmospheric pressure ... Keywords: Atmospheric pressure, Carbon nanotubes, Mass production, Plasma effects, Plasma enhanced chemical vapor deposition
Seok Seung Shin; Bum Ho Choi; Young Mi Kim; Jong Ho Lee; Dong Chan Shin
Burning plasmas
The fraction of fusion-reaction energy that is released in energetic charged ions, such as the alpha particles of the D-T reaction, can be thermalized within the reacting plasma and used to maintain its temperature. This mechanism facilitates the achievement of very high energy-multiplication factors Q, but also raises a number of new issues of confinement physics. To ensure satisfactory reaction operation, three areas of energetic-ion interaction need to be addressed: single-ion transport in imperfectly symmetric magnetic fields or turbulent background plasmas; energetic-ion-driven (or stabilized) collective phenomena; and fusion-heat-driven collective phenomena. The first of these topics is already being explored in a number of tokamak experiments, and the second will begin to be addressed in the D-T-burning phase of TFTR and JET. Exploration of the third topic calls for high-Q operation, which is a goal of proposed next-generation plasma-burning projects. Planning for future experiments must take into consideration the full range of plasma-physics and engineering R D areas that need to be addressed on the way to a fusion power demonstration.
Furth, H.P.; Goldston, R.J.; Zweben, S.J. (Princeton Univ., NJ (USA). Plasma Physics Lab.); Sigmar, D.J. (Massachusetts Inst. of Tech., Cambridge, MA (USA))
Plasma Catalytic Conversion of Methane in Ultra Rich Flame using Transient Gliding Arc Combustion Support
be carried out in a number of ways: steam reforming, thermo-catalytic reforming, partial oxidation, etc. [1
Interpretation of parabolic arcs in pulsar secondary spectra
Pulsar dynamic spectra sometimes show organised interference patterns; these patterns have been shown to have power spectra which often take the form of parabolic arcs, or sequences of inverted parabolic arclets whose apexes themselves follow a parabolic locus. Here we consider the interpretation of these arc and arclet features. We give a statistical formulation for the appearance of the power spectra, based on the stationary phase approximation to the Fresnel-Kirchoff integral. We present a simple analytic result for the power-spectrum expected in the case of highly elongated images, and a single-integral analytic formulation appropriate to the case of axisymmetric images. Our results are illustrated in both the ensemble-average and snapshot regimes. Highly anisotropic scattering appears to be an important ingredient in the formation of the observed arclets.
Mark Walker; Don Melrose; Dan Stinebring; Chengmin Zhang
A method is reported for inert arc welding. An a-c welding current is applied to the workpiece and welding electrode such that the positive portion of each cycle thereof, with the electrode positive, has only sufficient energy to clean the surface of the workpiece and the negative portion of each cycle thereof, with the electrode negative, contains the energy required to weld. (AEC)
SCI-Arc/Caltech Solar Decathlon 2011 Project Manual
CHIP CHIP 2 011 SCI---ARC / C altech S olar D ecathlon 2 011 As---Built P roject M anual 1 D.O.E. S olar D ecathlon 2 011 U.S. DEPARTMENT OF ENERGY SOLAR DECATHLON 2011 Team SCI-Arc/Caltech CHIP COMPACT HYPER_INSULATED PROTOTYPE Project Manual August 11,2011 Project Manager (Design and Construction): Reed Finlay (firstname.lastname@example.com) Project Manager (PR and Development): Elisabeth Neigert (email@example.com) CHIP 2 011 SCI---ARC / C altech S olar D ecathlon 2 011 As---Built P roject M anual 2 D.O.E. S olar D ecathlon 2 011 Table o f C ontents Summary o f C hanges 2 Rules C ompliance C hecklist 3 Structural C alculations 6 Detailed W ater B udget 7 Summary o f U nlisted E lectrical C omponents 9 Summary o f R econfigurable F eatures 10 Interconnection A pplication F orm 11 Energy A nalysis R esults a nd D iscussion
A Glove Box Enclosed Gas-Tungsten Arc Welding System
This report describes an inert atmosphere enclosed gas-tungsten arc welding system which has been assembled in support of the MC2730, MC2730A and MC 3500 Radioisotope Thermoelectric Generator (RTG) Enhanced Surveillance Program. One goal of this program is to fabricate welds with microstructures and impurity levels which are similar to production heat source welds previously produced at Los Alamos National Laboratory and the Mound Facility. These welds will subsequently be used for high temperature creep testing as part of the overall component lifetime assessment. In order to maximize the utility of the welding system, means for local control of the arc atmosphere have been incorporated and a wide range of welding environments can easily be evaluated. The gas-tungsten arc welding system used in the assembly is computer controlled, includes two-axis and rotary motion, and can be operated in either continuous or pulsed modes. The system can therefore be used for detailed research studies of welding impurity effects, development of prototype weld schedules, or to mimic a significant range of production-like welding conditions. Fixturing for fabrication of high temperature creep test samples have been designed and constructed, and weld schedules for grip-tab and test welds have been developed. The microstructure of these welds have been evaluated and are consistent with those used during RTG production.
Reevr, E, M; Robino, C.V.
Instrument Series: Deposition and Microfabrication
Deposition and Microfabrication Deposition and Microfabrication Sputter Deposition System Only available at EMSL, the Discovery ® Deposition System has been customized to be a fully automated multi-functional "hybrid" instrument with several modes for thin film processing, including multi-target sputtering, effusion cell deposition, electron beam deposition, and in-situ reflection high-energy electron diffraction (RHEED) materials characterization. Unlike most systems, the Discovery ® Deposition System's unique configuration offers operational flexibility, efficiency, and control, allowing a range of applications and materials to be processed simultaneously. Because it is software controlled, users can provide their own "recipes" and have a complete log of what happens throughout the
Narrow groove gas tungsten arc welding of ASTM A508 Class 4 steel for improved toughness properties
Welding of heavy section steel has traditionally used the automatic submerged arc welding (ASAW) process because of the high deposition rates achievable. However, the properties, particularly fracture toughness, of the weld are often inferior when compared to base material. This project evaluated the use of narrow groove gas tungsten arc welding (GTAW) to improve weld material properties. The welding procedures were developed for ASTM A508 Class 4 base material using a 1% Ni filler material complying to AWS Specification A.23-90-EF3-F3-N. A narrow groove joint preparation was used in conjunction with the GTAW process so competitive fabrication rates could be achieved when compared to the ASAW process. Weld procedures were developed to refine weld substructure to achieve better mechanical properties. Two heaters of weld wire were used to examine the effects of minor filler metal chemistry differences on weld mechanical properties. Extensive metallographic evaluations showed excellent weld quality with a refined microstructure. Chemical analysis of the weld metal showed minimal weld dilution by the base metal. Mechanical testing included bend and tensile tests to ensure weld quality and strength. A Charpy impact energy curve versus temperature and fracture toughness curve versus temperature were developed for each weld wire heat. Results of fracture toughness and Charpy impact testing indicated an improved transition temperature closer to that of the base material properties.
Penik, M.A. Jr. [Rensselaer Polytechnic Inst., Troy, NY (United States)
A Miocene Island-Arc Volcanic Seamount- The Takashibiyama Formation...
lava fragments andor pyroclastic materials, and are similar in internal features to debris flow and turbidite deposits. Subaqueous block lavas and minor pillow lavas form...
Analytical and experimental studies for thermal plasma processing of materials
Work continued on thermal plasma processing of materials. This quarter, ceramic powders of carbides, aluminium nitride, oxides, solids solutions, magnetic and non magnetic spinels, superconductors, and composites have been successfully synthesized in a Triple DC Torch Plasma Jet Reactor (TTPR) and in a single DC Plasma Jet Reactor. All the ceramic powders with the exception of AIN were synthesized using a novel injection method developed to overcome the problems associated with solid injection, in particular for the single DC plasma jet reactor, and to realize the benefits of gas phase reactions. Also, initial experiments have been performed for the deposition of diamond coatings on Si wafers using the TTPR with methane as the carbon source. Well faceted diamond crystallites were deposited on the surface of the wafers, forming a continuous one particle thick coating. For measuring temperature and velocity fields in plasma systems, enthalpy probes have been developed and tested. The validity has been checked by performing energy and mass flux balances in an argon plasma jet operated in argon atmosphere. Total Gibbs free energy minimization calculations using a quasi-equilibrium modification have been applied to simulate several chemical reactions. Plasma reactor modelling has been performed for the counter-flow liquid injection plasma synthesis experiment. Plasma diagnostics has been initiated to determine the pressure gradient in the coalesced part of the plasma jet. The pressure gradient drives the diffusion of chemical species which ultimately controls the chemical reactions. 4 figs.
Plasma enhanced chemical vapor deposition vanadium oxide thin ...
... exhibits a high discharge capacity, a high energy density, and a negligible capacity fade fiom its second cycle to at least 2,900 cycles, ...
Engineering properties of superhard films with ion energy and post-deposition processing
Recent developments in plasma synthesis of hard materials using energetic ions are described. Metal Plasma Immersion Ion Implantation and Deposition (MePIIID) has been used to prepare several hard films: from diamondlike carbon (DLC) to carbides, from nitrides to oxides. The energy of the depositing species is controlled to maximize adhesion as well as to change the physical and chemical properties of the films. Adhesion is promoted by the creation of a graded interface between the film and the substrate. The energy of the depositing ions is also used to modify and control the intrinsic stresses and the microstructure of the films. The deposition is carried out at room temperature, which is important for temperature sensitive substrates. A correlation between intrinsic stresses and the energetics of the deposition is presented for the case of DLC films, and means to reduce stress levels are discussed.
Monteiro, Othon R.; Delplancke-Ogletree, Mari-Paule
Comprehensive physical models and simulation package for plasma/material interactions during plasma instabilities.
Damage to plasma-facing components (PFCS) from plasma instabilities remains a major obstacle to a successful tokamak concept. The extent of the damage depends on the detailed physics of the disrupting plasma, as well as on the physics of plasma-material interactions. A comprehensive computer package called High Energy Interaction with General Heterogeneous Target Systems (HEIGHTS) has been developed and consists of several integrated computer models that follow the beginning of a plasma disruption at the scrape-off layer (SOL) through the transport of the eroded debris and splashed target materials to nearby locations as a result of the deposited energy. The package can study, for the first time, plasma-turbulent behavior in the SOL and predict the plasma parameters and conditions at the divertor plate. Full two-dimensional (2-D) comprehensive radiation magnetohydrodynamic (MHD) models are coupled with target thermodynamics and liquid hydrodynamics to evaluate the integrated response of plasma-facing materials. Factors that influence the lifetime of plasma-facing and nearby components, such as loss of vapor-cloud confinement and vapor removal due to MHD effects, damage to nearby components due to intense vapor radiation, melt splashing, and brittle destruction of target materials, are also modeled and discussed.
Low Power Laser Hybrid Gas Metal Arc Welding on A36 Steel
Presentation Title, Low Power Laser Hybrid Gas Metal Arc Welding on A36 Steel. Author(s), Caleb Roepke, Stephen Liu, Shawn Kelly, Rich Martukanitz. On-Site ...
Voltage Node Arcing in the ICRH Antenna Vacuum Transmission Lines at JET
The observation of parasitic low-VSWR activity during operations of JET RF plant and the damage caused by arcing at the voltage-node in the vacuum transmission line (VTL) in 2004 highlight the importance of the problem of low-voltage breakdown in the ICRH systems. Simulations demonstrate little response of the RF circuit to the voltage-node arcing which explains why it remains largely unnoticed and complicates the design of protection systems. Analysis of the damage pattern produced by the voltage-node arcing suggests that multipactor-related phenomena occurring at elevated voltage thresholds in conditions of unfavorable VTL geometry are most plausible arc-provoking factors.
Monakhov, I.; Graham, M.; Mayoral, M.-L.; Nicholls, K.; Walden, A. [Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Bobkov, V. [Max-Planck Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)
High rate chemical vapor deposition of carbon films using fluorinated gases
A high rate, low temperature deposition of amorphous carbon films is produced by PE-CVD in the presence of a fluorinated or other halide gas. The deposition can be 5 performed at less than 100C, including ambient room temperature, with a radio frequency plasma assisted chemical vapor deposition process. With less than 6.5 at% fluorine incorporated into the amorphous carbon film, the characteristics of the carbon film, including index of 10 refraction, mass density, optical clarity, and chemical resistance are within 15% of those characteristics for pure amorphous carbon films, but the deposition rates are high.
Stafford, B.L.; Tracy, C.E.; Benson, D.K.; Nelson, A.J.
A high rate, low-temperature deposition of amorphous carbon films is produced by PE-CVD in the presence of a fluorinated or other halide gas. The deposition can be performed at less than 100.degree. C., including ambient room temperature, with a radio frequency plasma assisted chemical vapor deposition process. With less than 6.5 atomic percent fluorine incorporated into the amorphous carbon film, the characteristics of the carbon film, including index of refraction, mass density, optical clarity, and chemical resistance are within fifteen percent (15%) of those characteristics for pure amorphous carbon films, but the deposition rates are high.
Stafford, Byron L. (Arvada, CO); Tracy, C. Edwin (Golden, CO); Benson, David K. (Golden, CO); Nelson, Arthur J. (Longmont, CO)
A dimensionless parameter model for arc welding processes
A dimensionless parameter model previously developed for C0{sub 2} laser beam welding has been shown to be applicable to GTAW and PAW autogenous arc welding processes. The model facilitates estimates of weld size, power, and speed based on knowledge of the material`s thermal properties. The dimensionless parameters can also be used to estimate the melting efficiency, which eases development of weld schedules with lower heat input to the weldment. The mathematical relationship between the dimensionless parameters in the model has been shown to be dependent on the heat flow geometry in the weldment.
Fuerschbach, P.W.
Evaluation of Cracks in ABB HK Arc Chutes
The nuclear power industry has a number of medium voltage (5 Kv-15 Kv) ABB HK air-magnetic circuit breakers with cracks in various places on the ceramic liner plate and cold-molded asbestos portions of the arc chutes. These cracks may or may not be cosmetic. This "jump gap crack" issue has been discussed in several ABB circuit breaker users group meetings. Five utilities (Brunswick, Seabrook, TVA, Duke, and Vogtle) have previously expressed interest in this issue. The present ABB Quality Assurance Proced...
Energy Deposition Using EGS4
are used to model the energy deposition in 0.4 r.l. Ti due to photons produced by the Tesla TRD undulator driven by the 250 GeV Tesla primary electron beam. 1 Energy Deposition...
Oil shale deposits of Thailand
Oil-shale deposits occur in several areas of Thailand. Perhaps the most important deposit occurs at Mae Sod in Tak Province, West Thailand. Other well-known deposits are Li in Lamphum Province, Ko Kha District, Lampang Province, and Krabi in the southern peninsular region. The geological age of all these deposits is late Tertiary, as demonstrated by the presence of the fossils from the oil shale of the Mae Sod series, e.g., fish of the Ostariophysian family Cyprinidae.
Chakrabarti, A.K.
Thin Film Deposition and Processing
... Applications: Tube 1 (T1), open for future upgrade. Silicon Nitride Deposition (Tube 2): Low Stress recipe. Stoichiometric recipe. ...
Plasma analysis and diagnostics for high efficiency amorphous solar cell production. Final report
This is a project that sought to improve the amorphous silicon-germanium (SiGe) thin film deposition process in the production of solar cells. To accomplish this, the electron cyclotron resonance (ECR) plasma discharge, employed for the thin film deposition, was modified. Changes in the parameters of the plasma were monitored with diagnostic techniques, similar to those used in fusion plasma studies. That was the primary contribution from ORNL. Only one phase was contained in the statement of work, with the following tasks: (1) Develop a detailed program for plasma characterization. (2) Carry-out plasma modeling and analysis to support deposition systems design. (3) Operate experimental deposition systems for the purpose of plasma characterization. (4) Analyze data. (5) Modify deposition as directed by measurements. (6) This final report, which was deemed to be the only deliverable of this small project. And while the modified ECR discharge did not show measurable improvement of the conditions relevant to the deposition process, much was learned about the plasma parameters in the process. Some ideas on alternative designs are being discuss and funding options for testing such designed are being sought.
Klepper, C.C.
Thermal Treatment of Solid Wastes Using the Electric Arc Furnace
A thermal waste treatment facility has been developed at the Albany Research Center (ARC) over the past seven years to process a wide range of heterogeneous mixed wastes, on a scale of 227 to 907 kg/h (500 to 2,000 lb/h). The current system includes a continuous feed system, a 3-phase AC, 0.8 MW graphite electrode arc furnace, and a dedicated air pollution control system (APCS) which includes a close-coupled thermal oxidizer, spray cooler, baghouse, and wet scrubber. The versatility of the complete system has been demonstrated during 5 continuous melting campaigns, ranging from 11 to 25 mt (12 to 28 st) of treated wastes per campaign, which were conducted on waste materials such as (a) municipal incinerator ash, (b) simulated low-level radioactive, high combustible-bearing mixed wastes, (c) simulated low-level radioactive liquid tank wastes, (d) heavy metal contaminated soils, and (e) organic-contaminated dredging spoils. In all cases, the glass or slag products readily passed the U.S. Environmental Protection Agency (EPA) Toxicity Characteristic Leachability Program (TCLP) test. Additional studies are currently under way on electric utility wastes, steel and aluminum industry wastes, as well as zinc smelter residues. Thermal treatment of these solid waste streams is intended to produce a metallic product along with nonhazardous glass or slag products.
O'Connor, W.K.; Turner, P.C.
Gaseous divertor simulation in an arc-jet device
The first experimental simulation of the gaseous tokamak divertor is presented. Significant results are: (1) neutral gas at a pressure of a few mTorr is sufficient to absorb the entire localized flux of plasma thermal energy and reidstribute it over a wide area; (2) elastic ion-neutral collisions constitute the main energy absorbing process (at T/sub e,i/ less than or equal to 5 eV), and (3) a large pressure difference between divertor and main plasma chamber is maintained by plasma pumping in the connecting channel.
Hsu, W.L.; Yamada, M.; Barrett, P.J.
Virtually Arc Free High Power Pulsed Magnetron Sputtering Based ...
Bonding Mechanism of Cold Spray Coating on Magnesium Alloys ... Effect of Thermal Cycling and Sliding on the Structure of Cu-Nb Nanolaminates ... Sputtering Based on Oscillatory Voltage Wave Forms for Insulating Film Depositions.
Multi-chamber deposition system
A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.
Jacobson, Richard L. (Roseville, MN); Jeffrey, Frank R. (Shoreview, MN); Westerberg, Roger K. (Cottage Grove, MN)
Thermal Response of Tritiated Co-deposits from JET and TFTR to Transient Heat Pulses
High heat flux interactions with plasma-facing components have been studied at microscopic scales. The beam from a continuous wave neodymium laser was scanned at high speed over the surface of graphite and carbon fiber composite tiles that had been retrieved from TFTR (Tokamak Fusion Test Reactor) and JET (Joint European Torus) after D-T plasma operations. The tiles have a surface layer of amorphous hydrogenated carbon that was co-deposited during plasma operations, and laser scanning has released more than 80% of the co-deposited tritium. The temperature rise of the co-deposit was much higher than that of the manufactured material and showed an extended time history. The peak temperature varied dramatically (e.g., 1,436 C compared to >2,300 C), indicating strong variations in the thermal conductivity to the substrate. A digital microscope imaged the co-deposit before, during, and after the interaction with the laser and revealed 100-micron scale hot spots during the interaction. Heat pulse durations of order 100 ms resulted in brittle destruction and material loss from the surface, whilst a duration of =10 ms showed minimal changes to the co-deposit. These results show that reliable predictions for the response of deposition areas to off-normal events such as ELMs (edge-localized modes) and disruptions in next-step devices need to be based on experiments with tokamak generated co-deposits.
C.H. Skinner; N. Bekrisl; J.P. Coad; C.A. Gentile; A. Hassanein; R. Reiswig; S. Willms
Visual-based Intelligent Control System for Robotic Gas Metal Arc Welding
Sensing and control the weld pool is a crucial problem for robotic gas-metal arc welding (GMAW) process. In present research, a special vision sensing system, assisted by a narrow-band filter which could overcome the influence of the strong arc light ...
Shi Yu; Xue Cheng; Fan Ding; Chen Jianhong
Simulation of the flicker phenomenon based on modeling the electric arc
The Electric Arc Furnace (EAF) is a very large power load, determining the negative effects on the power quality like flicker effect, harmonics currents, and reactive power. These effects are due to the nonlinear characteristic of the electric arc. In ... Keywords: flicker, harmonics, interharmonics, power quality, simulation and modeling
Manuela Panoiu; Caius Panoiu; Ioan Sora; Raluca Rob
Carbon nanotubes and other fullerenes produced from tire powder injected into an electric arc
A novel method of growing multiwall carbon nanotubes by injecting tire powder into an electric arc has been developed. The process is optimized using a DC electric arc in pressurized helium. The multiwall carbon nanotube product and the optimization process are characterized by transmission electron microscopy.
Murr, L.E. [Department of Metallurgical and Materials Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States)]. E-mail: firstname.lastname@example.com; Brown, D.K. [Department of Metallurgical and Materials Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Esquivel, E.V. [Department of Metallurgical and Materials Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Ponda, T.D. [Department of Metallurgical and Materials Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Martinez, F. [Department of Metallurgical and Materials Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Virgen, A. [Department of Metallurgical and Materials Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States)
ArcMine: A GIS extension to support mine reclamation planning
This paper presents a new GIS extension, named ArcMine, developed to support reclamation planning in abandoned mining areas. ArcMine provides four tools to (a) assess mine subsidence hazards, (b) estimate the erosion of mine wastes, (c) analyze flow ... Keywords: GIS, Mine reclamation, Mine wastes, Mine water, Reforestation, Subsidence
Sung-Min Kim; Yosoon Choi; Jangwon Suh; Sungchan Oh; Hyeong-Dong Park; Suk-Ho Yoon; Wa-Ra Go
Chemical vapor deposition sciences
Chemical vapor deposition (CVD) is a widely used method for depositing thin films of a variety of materials. Applications of CVD range from the fabrication of microelectronic devices to the deposition of protective coatings. New CVD processes are increasingly complex, with stringent requirements that make it more difficult to commercialize them in a timely fashion. However, a clear understanding of the fundamental science underlying a CVD process, as expressed through computer models, can substantially shorten the time required for reactor and process development. Research scientists at Sandia use a wide range of experimental and theoretical techniques for investigating the science of CVD. Experimental tools include optical probes for gas-phase and surface processes, a range of surface analytic techniques, molecular beam methods for gas/surface kinetics, flow visualization techniques and state-of-the-art crystal growth reactors. The theoretical strategy uses a structured approach to describe the coupled gas-phase and gas-surface chemistry, fluid dynamics, heat and mass transfer of a CVD process. The software used to describe chemical reaction mechanisms is easily adapted to codes that model a variety of reactor geometries. Carefully chosen experiments provide critical information on the chemical species, gas temperatures and flows that are necessary for model development and validation. This brochure provides basic information on Sandia`s capabilities in the physical and chemical sciences of CVD and related materials processing technologies. It contains a brief description of the major scientific and technical capabilities of the CVD staff and facilities, and a brief discussion of the approach that the staff uses to advance the scientific understanding of CVD processes.
Working Principle of the Hollow-Anode Plasma Source Hollow-Anode Plasma
36240 36240 Plasma Sources Science and Technology 4 (1995) 571-575. Working Principle of the Hollow-Anode Plasma Source André Anders and Simone Anders Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 ABSTRACT The hollow-anode discharge is a special form of glow discharge. It is shown that a drastically reduced anode area is responsible for a positive anode voltage drop of 30-40 V and an increased anode sheath thickness. This leads to an ignition of a relatively dense plasma in front of the anode hole. Langmuir probe measurements inside a specially designed hollow anode plasma source give an electron density and temperature of n e = 10 9 -10 11 cm -3 and T e = 1 - 3 eV, respectively (nitrogen, current 100 mA, flow rate 5-50 scc/min). Driven by a pressure gradient, the "anode" plasma is blown through the anode hole and forms a bright plasma jet streaming with supersonic velocity (Mach number 1.2). The plasma stream can be used, for instance, in plasma-assisted deposition of thin films
SiO2 and Si etching in fluorocarbon plasmas: A detailed surface model coupled with a complete plasma and profile simulator.
A surface model for SiO"2 and Si etching in fluorocarbon plasmas is presented, taking into account polymer deposition. The polymer, the CF"x, and the F surface coverage is calculated, as well as the etching yields and rates. Transition from deposition ...
E. Gogolides; P. Vauvert; Y. Courtin; G. Kokkoris; R. Pelle; A. Boudouvis; G. Turban
Tunable molten oxide pool assisted plasma-melter vitrification systems
The present invention provides tunable waste conversion systems and apparatus which have the advantage of highly robust operation and which provide complete or substantially complete conversion of a wide range of waste streams into useful gas and a stable, nonleachable solid product at a single location with greatly reduced air pollution to meet air quality standards. The systems provide the capability for highly efficient conversion of waste into high quality combustible gas and for high efficiency conversion of the gas into electricity by utilizing a high efficiency gas turbine or an internal combustion engine. The solid product can be suitable for various commercial applications. Alternatively, the solid product stream, which is a safe, stable material, may be disposed of without special considerations as hazardous material. In the preferred embodiment, the arc plasma furnace and joule heated melter are formed as a fully integrated unit with a common melt pool having circuit arrangements for the simultaneous independently controllable operation of both the arc plasma and the joule heated portions of the unit without interference with one another. The preferred configuration of this embodiment of the invention utilizes two arc plasma electrodes with an elongated chamber for the molten pool such that the molten pool is capable of providing conducting paths between electrodes. The apparatus may additionally be employed with reduced use or without further use of the gases generated by the conversion process. The apparatus may be employed as a net energy or net electricity producing unit where use of an auxiliary fuel provides the required level of electricity production. Methods and apparatus for converting metals, non-glass forming waste streams and low-ash producing inorganics into a useful gas are also provided. The methods and apparatus for such conversion include the use of a molten oxide pool having predetermined electrical, thermal and physical characteristics capable of maintaining optimal joule heating and glass forming properties during the conversion process.
Titus, Charles H. (Newtown Square, PA); Cohn, Daniel R. (Chestnut Hill, MA); Surma, Jeffrey E. (Kennewick, WA)
Diameter tuning of single-walled carbon nanotubes by diffusion plasma CVD
We have realized a diameter tuning of single-walled carbon nanotubes (SWNTs) by adjusting process gas pressures with plasma chemical vapor deposition (CVD). Detailed photoluminescence measurements reveal that the diameter distribution of SWNTs clearly ...
Toshiaki Kato; Shunsuke Kuroda; Rikizo Hatakeyama
IOP PUBLISHING PLASMA PHYSICS AND CONTROLLED FUSION Plasma Phys. Control. Fusion 51 (2009) 014005 (9pp) doi:10.1088/0741-3335/51/1/014005
IOP PUBLISHING PLASMA PHYSICS AND CONTROLLED FUSION Plasma Phys. Control. Fusion 51 (2009) 014005 to inertial fusion [1] concerns the propagation and energy deposition of a fast electron beam in strongly change produced in the target material by the shock wave. While the initially cold solid target
Strathclyde, University of
Gas-tungsten arc welding of aluminum alloys
A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.
Frye, Lowell D. (Kingston, TN)
The present invention is directed to a gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to profice a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surface are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy continguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.
Frye, L.D.
Static Heat Loads in the LHC Arc Cryostats: Final Assessment
This note presents the final assessment of the static heat loads in the LHC arc cryostats, using different experimental methods during the first commissioning period in 2007. This assessment further develops and completes previous estimates made during the commissioning of sector 7_8 [1]. The estimate of the helium inventory, a prerequisite for the heat load calculation, is also presented. Heat loads to the cold mass are evaluated from the internal energy balance during natural as well as powered warm-ups of the helium baths in different subsector. The helium inventory is calculated from the internal energy balance during powered warm-ups and matched with previous assessments. Furthermore, heat loads to the thermal shield are estimated from the non-isothermal cooling of the supercritical helium in line E. The comparison of measured heat loads with previous estimates and with budgeted values is then presented, while their correlation with some important parameters like insulation vacuum pressure and some heat ...
Parma, V
Plasma Kinetic Theory
Kinetic Theory / Proceedings of the Ninth Carolus Magnus Summer School on Plasma and Fusion Energy Physics
B. Weyssow
currently dominated by indium tin oxide (ITO). In thismore established indium tin oxide (ITO). While ITO remains
on the properties of indium tin oxide thin films. J. Appl.optical properties in indium-tin-oxide thin film on glassthe replacement of indium tin oxide (ITO) for applications
Biological Optimization in Volumetric Modulated Arc Radiotherapy for Prostate Carcinoma
Purpose: To investigate the potential benefits achievable with biological optimization for modulated volumetric arc (VMAT) treatments of prostate carcinoma. Methods and Materials: Fifteen prostate patient plans were studied retrospectively. For each case, planning target volume, rectum, and bladder were considered. Three optimization schemes were used: dose-volume histogram (DVH) based, generalized equivalent uniform dose (gEUD) based, and mixed DVH/gEUD based. For each scheme, a single or dual 6-MV, 356 Degree-Sign VMAT arc was used. The plans were optimized with Pinnacle{sup 3} (v. 9.0 beta) treatment planning system. For each patient, the optimized dose distributions were normalized to deliver the same prescription dose. The quality of the plans was evaluated by dose indices (DIs) and gEUDs for rectum and bladder. The tallied DIs were D{sub 1%}, D{sub 15%}, D{sub 25%}, and D{sub 40%}, and the tallied gEUDs were for a values of 1 and 6. Statistical tests were used to quantify the magnitude and the significance of the observed differences. Monitor units and treatment times for each optimization scheme were also assessed. Results: All optimization schemes generated clinically acceptable plans. The statistical tests indicated that biological optimization yielded increased organs-at-risk sparing, ranging from {approx}1% to more than {approx}27% depending on the tallied DI, gEUD, and anatomical structure. The increased sparing was at the expense of longer treatment times and increased number of monitor units. Conclusions: Biological optimization can significantly increase the organs-at-risk sparing in VMAT optimization for prostate carcinoma. In some particular cases, however, the DVH-based optimization resulted in superior treatment plans.
Mihaylov, Ivaylo B., E-mail: email@example.com [Department of Radiation Oncology, Rhode Island Hospital/Brown Medical Center, Providence, RI (United States); Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AK (United States); Fatyga, Mirek [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA 23298 (United States); Bzdusek, Karl [Philips Radiation Oncology Systems, Fitchburg, WI (United States); Gardner, Kenneth; Moros, Eduardo G. [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AK (United States)
Plasma sweeper. [Patents
A device is described for coupling RF power (a plasma sweeper) from RF power introducing means to a plasma having a magnetic field associated therewith comprises at least one electrode positioned near the plasma and near the RF power introducing means. Means are described for generating a static electric field at the electrode directed into the plasma and having a component substantially perpendicular to the plasma magnetic field such that a non-zero vector cross-product of the electric and magnetic fields exerts a force on the plasma causing the plasma to drift.
Motley, R.W.; Glanz, J.
(Acidic deposition and the environment)
The travelers presented several papers at the Fourth International Conference on Acidic Deposition. These covered the following topics: atmospheric chemistry and deposition of airborne nitrogen compounds, soil solution chemistry in high-elevation spruce forests, and forest throughfall measurements for estimating total sulfur deposition to ecosystems. In addition, S. E. Lindberg was invited to organize and chair a conference session on Throughfall and Stemflow Experiments, and to present an invited lecture on Atmospheric Deposition and Canopy Interactions of Metals and Nitrogen in Forest Ecosystems: The Influence of Global Change'' at the 110th Anniversary Celebration of the Free University of Amsterdam.
Garten, C.T.; Lindberg, S.E.; Van Miegroet, H.
Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.
Article 690.11 in the 2011 National Electrical Code{reg_sign} (NEC{reg_sign}) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc fault protection device. Currently there is little experimental or empirical research into the behavior of the arcing frequencies through PV components despite the potential for modules and other PV components to filter or attenuate arcing signatures that could render the arc detector ineffective. To model AC arcing signal propagation along PV strings, the well-studied DC diode models were found to inadequately capture the behavior of high frequency arcing signals. Instead dynamic equivalent circuit models of PV modules were required to describe the impedance for alternating currents in modules. The nonlinearities present in PV cells resulting from irradiance, temperature, frequency, and bias voltage variations make modeling these systems challenging. Linearized dynamic equivalent circuits were created for multiple PV module manufacturers and module technologies. The equivalent resistances and capacitances for the modules were determined using impedance spectroscopy with no bias voltage and no irradiance. The equivalent circuit model was employed to evaluate modules having irradiance conditions that could not be measured directly with the instrumentation. Although there was a wide range of circuit component values, the complex impedance model does not predict filtering of arc fault frequencies in PV strings for any irradiance level. Experimental results with no irradiance agree with the model and show nearly no attenuation for 1 Hz to 100 kHz input frequencies.
Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan
The Absence of Plasma in "Spark Plasma Sintering"
investigations on the spark plasma sintering/synthesisinvestigations on the spark plasma sintering/synthesisLichtenberg, Principles of Plasma Discharges and Materials
Hulbert, Dustin M.
Princeton University Plasma Physics Laboratory, Princeton, New Jersey. Annual report, October 1, 1990--September 30, 1991
This report discusses the following topics: Principal parameters of experimental devices; Tokamak Fusion Test Reactor; Burning Plasma Experiment; Princeton Beta Experiment-Modification; Current Drive Experiment-Upgrade; International Thermonuclear Experimental Reactor; International Collaboration; X-Ray Laser Studies; Hyperthermal Atomic Beam Source; Pure Electron Plasma Experiments; Plasma Processing: Deposition and Etching of Thin Films; Theoretical Studies; Tokamak Modeling; Engineering Department; Environment, Safety, and Health and Quality Assurance; Technology Transfer; Office of Human Resources and Administration; PPPL Patent Invention Disclosures; Office of Resource Management; Graduate Education: Plasma Physics; Graduate Education: Program in Plasma Science and Technology; and Science Education Program.
Plasma diagnostics | Princeton Plasma Physics Lab
of superheated and electrically charged gases known as plasmas. PPPL and ITER: Lab teams support the world's largest fusion experiment with leading-edge ideas and...
Plasma Astrophysics | Princeton Plasma Physics Lab
which gives rise to astrophysical events that include auroras, solar flares and geomagnetic storms. The process occurs when the magnetic field lines in plasmas break and...
Interdisciplinary plasma theory workshop | Princeton Plasma Physics...
Interdisciplinary plasma theory workshop April 15, 2013 Tweet Widget Facebook Like Google Plus One (Photo by Elle Starkman PPPL Office of Communications) PPPL postdoctoral fellow...
Plasma processes in non-ideal plasmas
Non-ideal plasma equation of state, radiative cross-sections and energy exchange coefficients are described in a tutorial overview.
More, R.M.
Variable temperature semiconductor film deposition
A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.
Li, X.; Sheldon, P.
Particle Deposition in Granular Media
Objective is to understand aerosol deposition from gas streams flowing through granular media; this is important to the design of granular filtration systems. The following investigations were carried out: transient behavior of granular filtration of aerosols, and stochastic simulation of aerosol deposition in granular media.
Tien, C.
Hydrothermal Deposition | Open Energy Information
Hydrothermal Deposition Hydrothermal Deposition Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Hydrothermal Deposition Dictionary.png Hydrothermal Deposition: No definition has been provided for this term. Add a Definition Quartz veins indicate ancient fluid flow, possibly the result of a hydrothermal system (reference: http://www.nvcc.edu/home/cbentley/dc_rocks/) Tufa mounds indicate the location of extinct hot springs. In this photo they show the ancient extent of the surface manifestations at Mono Lake, CA (reference: http://news.medill.northwestern.edu/climatechange/page.aspx?id=170704)(photo by Scott Stine) Hydrothermal water carries minerals as it travels through the crust. These minerals are often deposited as pressure decreases as the fluid approaches
Application of a Plasma Powder Welding to engine valves
In hardfacing of automobile engine valves made of heat resisting steel such as 21-4N, conventional oxy-acetylene gase welding has been currently conducted manually by well trained operators because of using cast Stellite rods as the filler. In accordance with the strong demands of automatic welding, the authors newly developed an automatically controlled Plasma Powder Welding (PPW) system. This system is characterized by the application of a high thermal density plasma arc as heat source and by using power filler which melts more easily than bar cast rods. Moreover, this PPW system has been applied to the automotive engine valve production line and resulted in the great contribution to manpower saving.
Takeuchi, Y.; Nagata, M.
Ion-plasma gun for ion-milling machine
An ion gun includes an elongated electrode with a hollow end portion closed by a perforated end plate. The end plate is positioned parallel to a perforated flat electrode of opposite electrical polarity. An insulated sleeve encompasses the elongated electrode and extends outwardly from the perforated end towards the flat electrode. The sleeve length is separated into two portions of different materials. The first is formed of a high-temperature material that extends over the hollow portion of the elongated electrode where the arc is initiated by a point source electrode. The second sleeve portion extending over the remainder of the elongated electrode is of a resilient material for enhanced seal-forming ability and retention of plasma gas. Perforations are arranged in the flat electrode in a mutually opposing triangular pattern to project a plasma beam having a generally flat current profile towards a target requiring precision milling.
Kaminsky, Manfred S. (Hinsdale, IL); Campana, Jr., Thomas J. (Hinsdale, IL)
Rapid plasma heating by collective interactions, using strong turbulence and relativistic electron beams
A multi-kilovolt, moderate density plasma was generated in a magnetic mirror confinement system by two methods: turbulent heating and relativistic electron beam. Extensive diagnostic development permitted the measurement of important plasma characteristics, leading to interesting and novel conclusions regarding heating and loss mechanisms. Electron and ion heating mechanisms were categorized, and parameter studies made to establish ranges of importance. Nonthermal ion and electron energy distributions were measured. Beam propagation and energy deposition studies yielded the spatial dependence of plasma heating.
Wharton, C.B.
238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc
238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc 238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: 238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc Details Activities (0) Areas (0) Regions (0) Abstract: Activities of 238U decay series radioisotopes have been determined for both postcaldera basalts erupted between 1849 and 1974 and genetically related young precaldera dacites from Batur volcano, Bali, Sunda arc. All rocks possess (230Th/238U) = 1 within 2 sigma error indicating that little, if any, fractionation between Th and U occurred during their genesis, or in their source regions, within approximately the last 350 ka. Both the basaltic and the dacitic rocks possess (230Th/232U) ~
An Archean Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine
Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine Group, Abitibi Greenstone Belt, Canada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Archean Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine Group, Abitibi Greenstone Belt, Canada Details Activities (0) Areas (0) Regions (0) Abstract: The 2730-Ma-old Hunter Mine Group (HMG), a dominantly felsic subaqueous volcanic sequence, was formed during early arc construction in the Abitibi greenstone belt (Quebec, Canada). The western part of the HMG contains a felsic dyke swarm up to 1.5 km wide and traceable up-section for 2.5 km. Five distinct generations were identified: (1) aphanitic to feldspar-phyric dykes; (2) quartz-feldspar-phyric dykes with < 5% quartz
As oil and gas production moves to deeper and colder water, subsea multiphase production systems become critical for economic feasibility. It will also become increasingly imperative to adequately identify the conditions for paraffin precipitation and predict paraffin deposition rates to optimize the design and operation of these multiphase production systems. Although several oil companies have paraffin deposition predictive capabilities for single-phase oil flow, these predictive capabilities are not suitable for the multiphase flow conditions encountered in most flowlines and wellbores. For deepwater applications in the Gulf of Mexico, it is likely that multiphase production streams consisting of crude oil, produced water and gas will be transported in a single multiphase pipeline to minimize capital cost and complexity at the mudline. Existing single-phase (crude oil) paraffin deposition predictive tools are clearly inadequate to accurately design these pipelines because they do not account for the second and third phases, namely, produced water and gas. The objective of this program is to utilize the current test facilities at The University of Tulsa, as well as member company expertise, to accomplish the following: enhance our understanding of paraffin deposition in single and two-phase (gas-oil) flows; conduct focused experiments to better understand various aspects of deposition physics; and, utilize knowledge gained from experimental modeling studies to enhance the computer programs developed in the previous JIP for predicting paraffin deposition in single and two-phase flow environments. These refined computer models will then be tested against field data from member company pipelines. The following deliverables are scheduled during the first three projects of the program: (1) Single-Phase Studies, with three different black oils, which will yield an enhanced computer code for predicting paraffin deposition in deepwater and surface pipelines. (2) Two-Phase Studies, with a focus on heat transfer and paraffin deposition at various pipe inclinations, which will be used to enhance the paraffin deposition code for gas-liquid flow in pipes. (3) Deposition Physics and Water Impact Studies, which will address the aging process, improve our ability to characterize paraffin deposits and enhance our understanding of the role water plays in paraffin deposition in deepwater pipelines. As in the previous two studies, knowledge gained in this suite of studies will be integrated into a state-of-the-art three-phase paraffin deposition computer program.
Michael Volk; Cem Sarica
Stainless steel submerged arc weld fusion line toughness
This effort evaluated the fracture toughness of austenitic steel submerged-arc weld (SAW) fusion lines. The incentive was to explain why cracks grow into the fusion line in many pipe tests conducted with cracks initially centered in SAWS. The concern was that the fusion line may have a lower toughness than the SAW. It was found that the fusion line, Ji. was greater than the SAW toughness but much less than the base metal. Of greater importance may be that the crack growth resistance (JD-R) of the fusion line appeared to reach a steady-state value, while the SAW had a continually increasing JD-R curve. This explains why the cracks eventually turn to the fusion line in the pipe experiments. A method of incorporating these results would be to use the weld metal J-R curve up to the fusion-line steady-state J value. These results may be more important to LBB analyses than the ASME flaw evaluation procedures, since there is more crack growth with through-wall cracks in LBB analyses than for surface cracks in pipe flaw evaluations.
Rosenfield, A.R.; Held, P.R.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)
Silicon solar cells made by a self-aligned, selective-emitter, plasma-etchback process
A potentially low-cost process for forming and passivating a selective emitter. The process uses a plasma etch of the heavily doped emitter to improve its performance. The grids of the solar cell are used to mask the plasma etch so that only the emitter in the region between the grids is etched, while the region beneath the grids remains heavily doped for low contact resistance. This process is potentially low-cost because it requires no alignment. After the emitter etch, a silicon nitride layer is deposited by plasma-enhanced, chemical vapor deposition, and the solar cell is annealed in a forming gas.
Ruby, Douglas S. (Albuquerque, NM); Schubert, William K. (Albuquerque, NM); Gee, James M. (Albuquerque, NM)
Toroidal midplane neutral beam armor and plasma limiter
For use in a tokamak fusion reactor having a midplane magnetic coil on the inner wall of an evacuated toriodal chamber within which a neutral beam heated, fusing plasma is magnetically confined, a neutral beam armor shield and plasma limiter is provided on the inner wall of the toroidal chamber to shield the midplane coil from neutral beam shine-thru and plasma deposition. The armor shield/plasma limiter forms a semicircular enclosure around the midplane coil with the outer surface of the armor shield/plasma limiter shaped to match, as closely as practical, the inner limiting magnetic flux surface of the toroidally confined, indented, bean-shaped plasma. The armor shield/plasma limiter includes a plurality of semicircular graphite plates each having a pair of coupled upper and lower sections with each plate positioned in intimate contact with an adjacent plate on each side thereof so as to form a closed, planar structure around the entire outer periphery of the circular midplane coil. The upper and lower plate sections are adapted for coupling to heat sensing thermocouples and to a circulating water conduit system for cooling the armor shield/plasma limiter.The inner center portion of each graphite plate is adapted to receive and enclose a section of a circular diagnostic magnetic flux loop so as to minimize the power from the plasma confinement chamber incident upon the flux loop.
Kugel, Henry W. (Somerset, NJ); Hand, Jr, Samuel W. (Hopewell Township, Mercer County, NJ); Ksayian, Haig (Titusville, NJ)
Development of an ArcGIS-pollutant load application (PLOAD) tool
Many of the findings of previous studies have indicated that there is a direct correlation between water quality and urbanization. Increasing impervious coverage typically results in a decrease in water quality. The purpose of this study was to adapt an automated tool for assessing the Pollutant Load Application (PLOAD). Created by CH2M HILL, a fullservice engineering and construction enterprise, PLOAD is a simplified GIS-based model used to calculate pollutants within a watershed. The so-called "simple method" implemented by PLOAD and discussed in this thesis has been endorsed by the EPA as a viable screening tool for National Pollutant Discharge Elimination System (NPDES) stormwater projects. This model was designed to be used with ArcView 3.3. ArcView 3.3 is a depreciated product, the capabilities of which have been replaced by ArcGIS 9.1. Using the same GIS data and tabular data required by PLOAD and custom ArcObjects scripting, a replacement, ArcGIS-PLOAD, was created. The current version of ArcGISPLOAD implements the "simple method" to calculate total pollutant load in pounds per year based on basin boundaries, precipitation in inches per year, ratio of storms producing runoff, parcel land use and parcel area, runoff coefficient for each land use, event mean pollutant concentrations for each land use. Time comparisons between the original PLOAD and the new ArcGIS-PLOAD revealed significant improvements. Both versions of PLOAD produce an intersection between the basin boundary and the land use layer. Calculations are actually done to the intersect layer. It was also found that the original PLOAD disregarded an albeit small portion of the intersection polygons. The new version does not. With the creation of ArcGIS-PLOAD, it is anticipated that it will become a small step in assist the State of Texas in improving water quality.
Young, De'Etra Jenra
Low pressure arc discharge lamp apparatus with magnetic field generating means
A low-pressure arc discharge apparatus having a magnetic field generating means for increasing the output of a discharge lamp is disclosed. The magnetic field generating means, which in one embodiment includes a plurality of permanent magnets, is disposed along the lamp for applying a constant transverse magnetic field over at least a portion of the positive discharge column produced in the arc discharge lamp operating at an ambient temperature greater than about 25 C. 3 figs.
Grossman, M.W.; George, W.A.; Maya, J.
DC Arc Fault Detection and Circuit Interruption Technologies for Photovoltaic Systems
In the United States, much like the rest of the world, rapid growth in photovoltaic (PV) systems is currently taking place. These systems are being installed in open fields, on parking structures, and on residential or commercial rooftops. Unfortunately, electrical arcing within a PV system's DC circuits has caused some fires. DC-sourced electrical fires are difficult to extinguish if arcing originates from unprotected source circuits within a PV array. Several high-visibility structural fires ...
Basic and Kinetic Theory / Proceedings of the Tenth Carolus Magnus Summer School on Plasma and Fusion Energy Physics
Plasma-Thermal Synthesis
INL's Plasma-Thermal Synthesis process improves the conversion process for natural gas into liquid hydrocarbon fuels.
Particle deposition in ventilation ducts
Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the experimental measurements was applied to evaluate particle losses in supply and return duct runs. Model results suggest that duct losses are negligible for particle sizes less than 1 {micro}m and complete for particle sizes greater than 50 {micro}m. Deposition to insulated ducts, horizontal duct floors and bends are predicted to control losses in duct systems. When combined with models for HVAC filtration and deposition to indoor surfaces to predict the ultimate fates of particles within buildings, these results suggest that ventilation ducts play only a small role in determining indoor particle concentrations, especially when HVAC filtration is present. However, the measured and modeled particle deposition rates are expected to be important for ventilation system contamination.
Sippola, Mark R.
Modeling particle deposition on HVAC heat exchangers
DEPOSITION ON HVAC HEAT EXCHANGERS JA Siegel 1,3 * and WWof fin-and-tube heat exchangers by particle deposition leadsparticle deposition on heat exchanger surfaces. We present a
Siegel, J.A.; Nazaroff, W.W.
Method of chemical vapor deposition of boron nitride using polymeric cyanoborane
Polymeric cyanoborane is volatilized, decomposed by thermal or microwave plasma energy, and deposited on a substrate as an amorphous film containing boron, nitrogen and carbon. Residual carbon present in the film is removed by ammonia treatment at an increased temperature, producing an adherent, essentially stoichiometric boron nitride film.
Maya, Leon (Oak Ridge, TN)
The field emission properties of graphene aggregates films deposited on Fe-Cr-Ni alloy substrates
The graphene aggregates films were fabricated directly on Fe-Cr-Ni alloy substrates by microwave plasma chemical vapor deposition system (MPCVD). The source gas was a mixture of H2 and CH4 with flow rates of 100 sccm and 12 sccm, ...
Zhanling Lu; Wanjie Wang; Xiaotian Ma; Ning Yao; Lan Zhang; Binglin Zhang
Polymeric cyanoborane is volatilized, decomposed by thermal or microwave plasma energy, and deposited on a substrate as an amorphous film containing boron, nitrogen and carbon. Residual carbon present in the film is removed by ammonia treatment at an increased temperature, producing an adherent, essentially stoichiometric boron nitride film. 11 figs.
Maya, L.
Seasonalepisodic control of acid deposition
This report contains the climatological, technical and economic factors for episodic and seasonal control of emissions in existing power plants. Analyzing a large data set of acid deposition for the years 1982-85, we find ...
Fay, James A.
Linked Deposit Loan Program (Kentucky)
Energy.gov (U.S. Department of Energy (DOE))
The Linked Deposit Program provides loan financing for small businesses of up to $100,000 for up to 7 years. The State Investment Commission invests funds from the state's Abandoned Property Cash...
Model of detached plasmas
Recently a tokamak plasma was observed in TFTR that was not limited by a limiter or a divertor. A model is proposed to explain this equilibrium, which is called a detached plasma. The model consists of (1) the core plasma where ohmic heating power is lost by anomalous heat conduction and (2) the shell plasma where the heat from the core plasma is radiated away by the atomic processes of impurity ions. A simple scaling law is proposed to test the validity of this model.
Yoshikawa, S.; Chance, M.
Oxidation Behavior of In-Flight Molten Aluminum Droplets in the Twin-Wire Electric Arc Thermal Spray Process
This paper examines the in-flight oxidation of molten aluminum sprayed in air using the twin-wire electric arc (TWEA) thermal spray process. The oxidation reaction of aluminum in air is highly exothermic and is represented by a heat generation term in the energy balance. Aerodynamic shear at the droplet surface enhances the amount of in-flight oxidation by: (1) promoting entrainment and mixing of the surface oxides within the droplet, and (2) causing a continuous heat generation effect that increases droplet temperature over that of a droplet without internal circulation. This continual source of heat input keeps the droplets in a liquid state during flight. A linear rate law based on the Mott-Cabrera theory was used to estimate the growth of the surface oxide layer formed during droplet flight. The calculated oxide volume fraction of an average droplet at impact agrees well with the experimentally determined oxide content for a typical TWEA-sprayed aluminum coating, which ranges from 3.3 to 12.7%. An explanation is provided for the elevated, nearly constant surface temperature (~ 2000 oC) of the droplets during flight to the substrate and shows that the majority of oxide content in the coating is produced during flight, rather than after deposition.
Donna Post Guillen; Brian G. Williams
Chemical enhancement of surface deposition
A method and apparatus are disclosed for increasing the deposition of ions onto a surface, such as the adsorption of uranium ions on the detecting surface of a radionuclide detector. The method includes the step of exposing the surface to a complexing agent, such as a phosphate ion solution, which has an affinity for the dissolved species to be deposited on the surface. This provides, for example, enhanced sensitivity of the radionuclide detector. 16 figs.
Patch, K.D.; Morgan, D.T.
A method and apparatus for increasing the deposition of ions onto a surface, such as the adsorption of uranium ions on the detecting surface of a radionuclide detector. The method includes the step of exposing the surface to a complexing agent, such as a phosphate ion solution, which has an affinity for the dissolved species to be deposited on the surface. This provides, for example, enhanced sensitivity of the radionuclide detector.
Patch, Keith D. (Lexington, MA); Morgan, Dean T. (Sudbury, MA)
Vapor deposition of hardened niobium
A method of coating ceramic nuclear fuel particles containing a major amount of an actinide ceramic in which the particles are placed in a fluidized bed maintained at ca. 800.degree. to ca. 900.degree. C., and niobium pentachloride vapor and carbon tetrachloride vapor are led into the bed, whereby niobium metal is deposited on the particles and carbon is deposited interstitially within the niobium. Coating apparatus used in the method is also disclosed.
Blocher, Jr., John M. (Columbus, OH); Veigel, Neil D. (Columbus, OH); Landrigan, Richard B. (Columbus, OH)
BWR Fuel Deposit Sample Evaluation
River Bend Nuclear Power Station, a boiling water reactor (BWR) plant, experienced fuel defects during Cycle 11. The failed fuel pins were identified during the subsequent refueling outage. To assist analysis of the fuel failure root cause, crud flake deposit samples were collected for analyses. Results on the morphology and distribution of chemical elements in four tenacious crud flakes that are associated with the fuel failures are reported in EPRI report 1009733, BWR Fuel Deposit Sample Evaluation–Riv...
Quick, Efficient Film Deposition for Nanomaterials - Energy ...
Electricity Transmission; Energy Analysis; ... • Films can be deposited uniformly in a one-step deposition of nanoparticles with optimized drop distri ...
Rocky Mountain carbonate spring deposit development.
??Relict Holocene carbonate spring deposits containing diverse biotic and abiotic depositional textures are present at Fall Creek cold sulphur springs, Alberta, Fairmont Hot Springs, British… (more)
Rainey, Dustin
Aging of reflective roofs: soot deposition
Aging of reflective roofs: soot deposition Title Aging of reflective roofs: soot deposition Publication Type Journal Article Year of Publication 2002 Authors Berdahl, Paul, Hashem...
A Radon Progeny Deposition Model
The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly {sup 222}Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of {sup 210}Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.
Guiseppe, V. E. [University of South Dakota, Vermillion, South Dakota 57069 (United States); Elliott, S. R.; Hime, A.; Rielage, K. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Westerdale, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
A radon progeny deposition model
Rielage, Keith [Los Alamos National Laboratory; Elliott, Steven R [Los Alamos National Laboratory; Hime, Andrew [Los Alamos National Laboratory; Guiseppe, Vincent E [Los Alamos National Laboratory; Westerdale, S. [MIT
Thermal plasma processing of materials. Progress report, September 1, 1988--January 31, 1992
High-power laser and arc welding of thorium-doped iridium alloys
The arc and laser weldabilities of two Ir-0.3% W alloys containing 60 and 200 wt ppM Th have been investigated. The Ir-.03% W alloy containing 200 wt ppM Th is severely prone to hot cracking during gas tungsten-arc welding. Weld metal cracking results from the combined effects of heat-affected zone liquation cracking and solidification cracking. Scanning electron microscopic analysis of the fractured surface revealed patches of low-melting eutectic. The cracking is influenced to a great extent by the fusion zone microstructure and thorium content. The alloy has been welded with a continuous-wave high-power CO/sub 2/ laser system with beam power ranging from 5 to 10 kW and welding speeds of 8 to 25 mm/s. Successful laser welds without hot cracking have been obtained in this particular alloy. This is attributable to the highly concentrated heat source available in the laser beam and the refinement in fusion zone microstructure obtained during laser welding. Efforts to refine the fusion zone structure during gas tungsten-arc welding of Ir-0.3 % W alloy containing 60 wt ppM Th were partially successful. Here transverse arc oscillation during gas tungsten-arc welding refines the fusion zone structure to a certain extent. However, microstructural analysis of this alloy's laser welds indicates further refinement in the fusion zone microstructure than in that from the gas tungsten-arc process using arc oscillations. The fusion zone structure of the laser weld is a strong function of welding speed.
David, S.A.; Liu, C.T.
Theory and models of material erosion and lifetime during plasma instabilities in a tokamak environment.
Surface and structural damage to plasma-facing components (PFCs) due to the frequent loss of plasma confinement remains a serious problem for the tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination. Surface damage consists of vaporization, spallation, and liquid splatter of metallic materials. Structural damage includes large temperature increases in structural materials and at the interfaces between surface coatings and structural members. To evaluate the lifetimes of plasma-facing materials and nearby components and to predict the various forms of damage that they experience, comprehensive models (contained in the HEIGHTS computer simulation package) are developed, integrated self-consistently, and enhanced. Splashing mechanisms such as bubble boiling and various liquid magnetohydrodynamic instabilities and brittle destruction mechanisms of nonmelting materials are being examined. The design requirements and implications of plasma-facing and nearby components are discussed, along with recommendations to mitigate and reduce the effects of plasma instabilities on reactor components.
Hassanein, A.; Konkashbaev, I.
Development of a Coating Formulation Procedure for Ni-base Shielded Metal Arc Electrodes with Varying Core Wire Composition.
??In order for manufacturers of shielded metal arc welding (SMAW) electrodes to stay competitive, they must be able to have flexibility in the performance of… (more)
Gaal, Brian
Metal film deposition by laser breakdown chemical vapor deposition
Dielectric breakdown of gas mixtures can be used to deposit homogeneous thin films by chemical vapor deposition with appropriate control of flow and pressure conditions to suppress gas phase nucleation and particle formation. Using a pulsed CO/sub 2/ laser operating at 10.6 microns where there is no significant resonant absorption in any of the source gases, we have succeeded in depositing homogeneous films from several gas phase precursors by gas phase laser pyrolysis. Nickel and molybdenum from the respective carbonyls and tungsten from the hexafluoride have been examined to date. In each case the gas precursor is buffered to reduce the partial pressure of the reactants and to induce breakdown. The films are spectrally reflective and uniform over a large area. Films have been characterized by Auger electron spectroscopy, x-ray diffraction, pull tests, and resistivity measurements. The highest quality films have resulted from the nickel depositions. Detailed x-ray diffraction analysis of these films yields a very small domain size (approx. 50 A) consistent with rapid quenching from the gas phase reaction zone. This analysis also shows nickel carbide formation consistent with the temperature of the reaction zone and the Auger electron spectroscopy results which show some carbon and oxygen incorporation (8% and 1% respectively). Gas phase transport and condensation of the molybdenum carbonyl results in substantial carbon and oxygen contamination of the molybdenum films requiring heated substrates, a requirement not consistent with the goals of the program to maximize the quench rate of the deposition. Results from tungsten deposition experiments representing a reduction chemistry instead of the decomposition chemistry involved in the carbonyl experiments are also reported.
Jervis, T.R.
Current problems in plasma spray processing
This detailed report summarizes 8 contributions from a thermal spray conference that was held in late 1991 at Brookhaven National Laboratory (Upton, Long Island, NY, USA). The subject of ``Plasma Spray Processing`` is presented under subject headings of Plasma-particle interactions, Deposit formation dynamics, Thermal properties of thermal barrier coatings, Mechanical properties of coatings, Feed stock materials, Porosity: An integrated approach, Manufacture of intermetallic coatings, and Synchrotron x-ray microtomographic methods for thermal spray materials. Each section is intended to present a concise statement of a specific practical and/or scientific problem, then describe current work that is being performed to investigate this area, and finally to suggest areas of research that may be fertile for future activity.
Berndt, C.C.; Brindley, W.; Goland, A.N.; Herman, H.; Houck, D.L.; Jones, K.; Miller, R.A.; Neiser, R.; Riggs, W.; Sampath, S.; Smith, M.; Spanne, P. [State Univ. of New York, Stony Brook, NY (United States). Thermal Spray Lab.
This detailed report summarizes 8 contributions from a thermal spray conference that was held in late 1991 at Brookhaven National Laboratory (Upton, Long Island, NY, USA). The subject of Plasma Spray Processing'' is presented under subject headings of Plasma-particle interactions, Deposit formation dynamics, Thermal properties of thermal barrier coatings, Mechanical properties of coatings, Feed stock materials, Porosity: An integrated approach, Manufacture of intermetallic coatings, and Synchrotron x-ray microtomographic methods for thermal spray materials. Each section is intended to present a concise statement of a specific practical and/or scientific problem, then describe current work that is being performed to investigate this area, and finally to suggest areas of research that may be fertile for future activity.
Berndt, C.C.; Brindley, W.; Goland, A.N.; Herman, H.; Houck, D.L.; Jones, K.; Miller, R.A.; Neiser, R.; Riggs, W.; Sampath, S.; Smith, M.; Spanne, P. (State Univ. of New York, Stony Brook, NY (United States). Thermal Spray Lab.)
Laser-plasma interactions for fast ignition
In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multi-dimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporal evolution. Scaling with irradiation conditions such as laser intensity are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the compa...
Kemp, A J; Debayle, A; Johzaki, T; Mori, W B; Patel, P K; Sentoku, Y; Silva, L O
The design of a dogbone Recirculated Linear Accelerator, RLA, with linear-field multi-pass arcs was earlier developed [1] for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected at the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to the frequency readily available at CEBAF: 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it straightforward to implement
Beard, Kevin B. [JLAB, MUONS Inc.; Roblin, Yves R. [JLAB; Morozov, Vasiliy [JLAB; Bogacz, Slawomir Alex [JLAB; Krafft, Geoffrey A. [JLAB
Linear Fixed-Field Multi-Pass Arcs for Recirculating Linear Accelerators
Recirculating Linear Accelerators (RLA's) provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting the dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dog-bone RLA capable of transporting two beam passes with momenta different by a factor of two. We present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dog-bone RLA.
V.S. Morozov, S.A. Bogacz, Y.R. Roblin, K.B. Beard
Burning Plasma Science Workshop Astrophysics and Laboratory Plasmas
Burning Plasma Science Workshop Astrophysics and Laboratory Plasmas Robert Rosner The University of Chicago Dec. 12, 2000 Austin, TX (http://flash.uchicago.edu) #12;Burning Plasma Science Workshop Austin ÂĄ Plasma conditions ÂĄ Overview of plasma physics issues for astrophysics ÂĄ Specific examples #12;Burning
What is a plasma?
This introduction will define the plasma fourth state of matter, where we find plasmas on earth and beyond, and why they are useful. There are applications to many consumer items, fusion energy, scientific devices, satellite communications, semiconductor processing, spacecraft propulsion, and more. Since 99% of our observable universe is ionized gas, plasma physics determines many important features of astrophysics, space physics, and magnetosphere physics in our solar system. We describe some plasma characteristics, examples in nature, some useful applications, how to create plasmas. A brief introduction to the theoretical framework includes the connection between kinetic and fluid descriptions, quasi neutrality, Debye shielding, ambipolar electric fields, some plasma waves. Hands-on demonstrations follow. More complete explanations will follow next week.
Intrator, Thomas P. [Los Alamos National Laboratory
Princeton University, Plasma Physics Laboratory annual report, October 1, 1988--September 30, 1989
This report contains discussions on the following topics: principal parameters achieved in experimental devices (FY89); tokamak fusion test reactor; compact ignition tokamak; princeton beta experiment- modification; current drive experiment; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for (FY89); graduate education: plasma physics; graduate education: plasma science and technology; and Princeton Plasmas Physics Laboratory Reports (FY89).
Automated control of linear constricted plasma source array
An apparatus and method for controlling an array of constricted glow discharge chambers are disclosed. More particularly a linear array of constricted glow plasma sources whose polarity and geometry are set so that the contamination and energy of the ions discharged from the sources are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The quality of film along deposition "tracks" opposite the plasma sources can be measured and compared to desired absolute or relative values by optical and/or electrical sensors. Plasma quality can then be adjusted by adjusting the power current values, gas feed pressure/flow, gas mixtures or a combination of some or all of these to improve the match between the measured values and the desired values.
Anders, Andre (Albany, CA); Maschwitz, Peter A. (Martinsville, VA)
Power Balance in the ITER Plasma and Divertor
It is planned to use atomic processes to spread out most of the heating power over the first wall and side walls to reduce the heat loads on the plasma facing components in ITER to ~ 50 MW. Calculations indicate that there will be 100 MW in bremstrahlung radiation from the plasma center, 50 MW of radiation from the plasma edge inside the separatrix and 100 MW of radiation from the scrape-off layer and divertor plasma, leaving 50 MW of power to be deposited on the divertor plates. The radiation losses are enhanced by the injection of impurities such as Neon or Argon at acceptably low levels (~0.1 % Argon, etc.) 1.
Parallel resistivity and ohmic heating of laboratory dipole plasmas
The parallel resistivity is calculated in the long-mean-free-path regime for the dipole plasma geometry; this is shown to be a neoclassical transport problem in the limit of a small number of circulating electrons. In this regime, the resistivity is substantially higher than the Spitzer resistivity due to the magnetic trapping of a majority of the electrons. This suggests that heating the outer flux surfaces of the plasma with low-frequency parallel electric fields can be substantially more efficient than might be naively estimated. Such a skin-current heating scheme is analyzed by deriving an equation for diffusion of skin currents into the plasma, from which quantities such as the resistive skin-depth, lumped-circuit impedance, and power deposited in the plasma can be estimated. Numerical estimates indicate that this may be a simple and efficient way to couple power into experiments in this geometry.
Fox, W. [Center for Integrated Computation and Analysis of Reconnection and Turbulence, University of New Hampshire, Durham, New Hampshire 03824 (United States)
Anomalous radial transport in tokamak edge plasma
Transport in tokamak plasma . . . . . . . . . . . . . . .of tokamak plasma . . . . . . . . . 1.4 Dissertationtransport model for edge plasma . . . . . . 6.1 Anomalous
Bodi, Vasudeva Raghavendra Kowsik
Spark Plasma Sintering
Oct 21, 2010 ... Coupled Electro-Thermo-Mechanical Analysis of Conventional (SPS) and Free Pressureless (FPSPS) Spark-Plasma Sintering: Eugene ...
Plasma Processing Of Hydrocarbon
The Idaho National Laboratory (INL) developed several patented plasma technologies for hydrocarbon processing. The INL patents include nonthermal and thermal plasma technologies for direct natural gas to liquid conversion, upgrading low value heavy oil to synthetic light crude, and to convert refinery bottom heavy streams directly to transportation fuel products. Proof of concepts has been demonstrated with bench scale plasma processes and systems to convert heavy and light hydrocarbons to higher market value products. This paper provides an overview of three selected INL patented plasma technologies for hydrocarbon conversion or upgrade.
Grandy, Jon D; Peter C. Kong; Brent A. Detering; Larry D. Zuck
INL's Plasma-Borohydride process produces borohydride from sodium borate which is capable of forming a chemical hydride for a storage medium of hydrogen.
Plasma—Methane Reformation
INL thermal plasma methane reformation process produces hydrogen and elemental carbon from natural gas and other hydrocarbons, such as natural gas or ...
INL has developed a thermal plasma quench to cool the heat generated from rapid chemical reactions, preventing adverse reactions or decompositions to ...
Physics of Complex Plasmas.
??Physics of complex plasmas is a wide and varied field. In the context of this PhD thesis I present the major results from my research… (more)
Sütterlin, Robert
As oil and gas production moves to deeper and colder water, subsea multiphase production systems become critical for economic feasibility. It will also become increasingly imperative to adequately identify the conditions for paraffin precipitation and predict paraffin deposition rates to optimize the design and operation of these multi-phase production systems. Although several oil companies have paraffin deposition predictive capabilities for single-phase oil flow, these predictive capabilities are not suitable for the multiphase flow conditions encountered in most flowlines and wellbores. For deepwater applications in the Gulf of Mexico, it is likely that multiphase production streams consisting of crude oil, produced water and gas will be transported in a single multiphase pipeline to minimize capital cost and complexity at the mudline. Existing single-phase (crude oil) paraffin deposition predictive tools are clearly inadequate to accurately design these pipelines, because they do not account for the second and third phases, namely, produced water and gas. The objective of this program is to utilize the current test facilities at The University of Tulsa, as well as member company expertise, to accomplish the following: enhance our understanding of paraffin deposition in single and two-phase (gas-oil) flows; conduct focused experiments to better understand various aspects of deposition physics; and, utilize knowledge gained from experimental modeling studies to enhance the computer programs developed in the previous JIP for predicting paraffin deposition in single and two-phase flow environments. These refined computer models will then be tested against field data from member company pipelines.
Cem Sarica; Michael Volk
PPPL3252 Preprint: June 1997, UC420, 427 Role of Plasma Edge in the Direct Launch Ion
installed in Tokamak Fusion Test Reactor (TFTR) to test a concept of generating sheared flow 2 in order efficiency for the core deposition. In order to launch IBW, it is necessary to first couple to cold plasma that it is difficult to couple directly. There are two cold plasma waves which can couple directly to IBW, namely
A finite element analysis technique for predicting as-sprayed residual stresses generated by the plasma spray coating process
It is essential to analyze the residual stresses during the deposition of plasma sprayed coatings since they adversely affect the coatings' performance during their service. In this article, finite element coupled heat transfer and elastic-plastic thermal ... Keywords: Finite element analysis, Heat transfer, Plasma spraying, Residual stresses, Thermal barrier coatings
H. W. Ng; Z. Gan
PPPL-3252 -Preprint: June 1997, UC-420, 427 Role of Plasma Edge in the Direct Launch Ion
in Tokamak Fusion Test Reactor (TFTR) to test a concept of generating sheared flow2 in order to trigger efficiency for the core deposition. In order to launch IBW, it is necessary to first couple to cold plasma that it is difficult to couple directly. There are two cold plasma waves which can couple directly to IBW, namely
A Catalyst Wire-feed Arc Discharge for Synthesis of Carbon Nanotubes and
A Catalyst Wire-feed Arc Discharge for Synthesis of Carbon Nanotubes and A Catalyst Wire-feed Arc Discharge for Synthesis of Carbon Nanotubes and Graphene Particles This invention pertains to a highly effective arc-based synthesis of single wall carbon nanotubes and graphene particles using catalysts in the form of wires made from ion group alloys instead of commonly used catalyst powders. The catalyst wire can be introduced into the discharge either from the anode or cathode regions or into the inter-electrode gap. The catalyst introduction can be done automatically and controlled using feedback based on the ablation of the graphite electrode. To maintain simplicity and attractiveness for industrial applications, it is desirable that the catalyst composition be contained in a single wire alloy. No.: M-808 Inventor(s): Yevgeny Raitses
Dynamics of vaporization and dissociation during transient surface heating, with application to vacuum arcs
This report describes a model of vaporization and dissociation occurring as a result of intense heating over a localized area of a material surface. The balance of heat between the input power and losses due to vaporization, as well as radiation and conduction in the material, are considered. The model includes the effect of binary mass diffusion and changes of surface stoichiometry for multiple component materials. Effects of vapor recondensation are included. The model is then applied to the description of spot heating on a vacuum arc anode through the use of a simple power feedback model. Comparison of surface temperature measurements to model predictions are used to parametrically describe the arc behavior. Finally, extensive parametric analyses showing the effect of material property variations on the arc behavior are described.
Benson, D.A.
Test plan for BWID Phase 2 electric arc melter vitrification tests
This test plan describes the Buried Waste Integrated Demonstration (BWID), Phase 2, electric arc melter, waste treatment evaluation tests to be performed at the US Bureau of Mines (USBM) Albany Research Center. The BWID Arc Melter Vitrification Project is being conducted to evaluate and demonstrate existing industrial arc melter technology for thermally treating mixed transuranic-contaminated wastes and soils. Phase 1 baseline tests, performed during fiscal year 1993 at the USBM, were conducted on waste feeds representing incinerated buried mixed wastes and soils. In Phase 2, surrogate feeds will be processed that represent actual as-retrieved buried wastes from the Idaho National Engineering Laboratory`s Subsurface Disposal Area at the Radioactive Waste Management Complex.
Soelberg, N.R.; Turner, P.C.; Oden, L.L.; Anderson, G.L.
An improved algorithm for maintaining arc consistency in dynamic constraint satisfaction problems
Real world is dynamic in its nature, so techniques attempting to model the real world should take this dynamicity in consideration. A well known Constraint Satisfaction Problem (CSP) can be extended this way to a so called Dynamic Constraint Satisfaction Problem (DynCSP) that supports adding and removing constraints in runtime. As Arc Consistency is one of the major techniques in solving CSPs, its dynamic version is of a particular interest for DynCSPs. This paper presents an improved version of AC|DC-2 algorithm for maintaining maximal arc consistency after constraint retraction. This improvement leads to runtimes better than the so far fastest dynamic arc consistency algorithm DnAC-6 while keeping low memory consumption. Moreover, the proposed algorithm is open in the sense of using either non-optimal AC-3 algorithm keeping a minimal memory consumption or optimal AC-3.1 algorithm improving runtime for constraint addition but increasing a memory consumption.
Roman Barták; Pavel Surynek
Computational modeling study of the radial line slot antenna microwave plasma source with comparisons to experiments
The radial line slot antenna plasma source is a high-density microwave plasma source comprising a high electron temperature source region within the plasma skin depth from a coupling window and low electron temperature diffusion region far from the window. The plasma is typically comprised of inert gases like argon and mixtures of halogen or fluorocarbon gases for etching. Following the experimental study of Tian et al.[J. Vac. Sci. Technol. A 24, 1421 (2006)], a two-dimensional computational model is used to describe the essential features of the source. A high density argon plasma is described using the quasi-neutral approximation and coupled to a frequency-domain electromagnetic wave solver to describe the plasma-microwave interactions in the source. The plasma is described using a multispecies plasma chemistry mechanism developed specifically for microwave excitation conditions. The plasma is nonlocal by nature with locations of peak power deposition and peak plasma density being very different. The spatial distribution of microwave power coupling depends on whether the plasma is under- or over-dense and is described well by the model. The model predicts the experimentally observed low-order diffusion mode radial plasma profiles. The trends of spatial profiles of electron density and electron temperature over a wide range of power and pressure conditions compare well with experimental results.
Raja, Laxminarayan L. [Department of Aerospace Engineering and Engineering Mechanics, University of Texas at Austin, Austin, Texas 78712 (United States); Mahadevan, Shankar [Esgee Technologies Inc., 1301 S. Capital of Texas Hwy. Suite B-122, Austin, Texas 78746 (United States); Ventzek, Peter L. G.; Yoshikawa, Jun [Tokyo Electron Ltd., Akasaka Biz Tower, 3-1 Akasaka 5-chome, Minato-ku, Tokyo 107-6325 (Japan)
Current initiation in low-density foam z-pinch plasmas