 sees a continuous DC field, as the field rotates at the same rate as the electron as it spirals around the magnetic field line. The electron energy increases until some other process limits the energy. The ultimate limit for magnetic mirror machines occurs when the electron energy is high enough that the adiabatic invariant is no longer conserved and electrons are no longer trapped in the mirror. Hot electrons are generally produced by using twice the fundamental frequency, which is more effective at heating hotter particles.
In most of these devices there are particular reasons for producing the hot electron population. Hot electrons take almost all their energy with them when they are hot because their energies are so much greater than the plasma potential
They also tend to absorb more RF power than colder electrons. For a thruster, all the power entering the warm or hot electrons is simply wasted. All ECR plasmas on which there were diagnostics capable of observing bot electrons have shown split electron populations. Power balance calculations show that about 1% of the RF power was going into the cold plasma in the ECR plasma and somewhere between 50% and 100% of the RF went into the cold plasma in the lower hybrid generated plasma. It would be desirable to have a RF plasma thruster which has high efficiency, utilizes lower frequency RF sources than ECR beating, and does not suffer from hot electron runaway.
RF plasma thrusters are also simpler than electromagnetic thrusters, which generally have currents perpendicular to the magnetic field, which crossed with the magnetic field produces the thrust. The currents produce their own magnetic field, which in the worst case can go unstable. In any case, the current produces its own magnetic field which interacts with the imposed magnetic field. This makes scaling of devices to different sizes difficult. By contrast, in the RF plasma thruster each flux tube is like any other. The rapid axial transport of particles compared to radial movements means there is little interaction between flux tubes, so scaling up (or down) in size is very predictable.
It would be desirable to have a RF plasma thruster that does not suffer from poor efficiency while providing a high specific impulse, high power density and is adaptable to many different applications.
8) Magnetohydrodynamic Generator
The MHD (magnetohydrodynamic) generator transforms thermal energy and kinetic energy directly into electricity. MHD generators are different from traditional electric generators in that they operate at high temperatures without moving parts. MHD was developed because the hot exhaust gas of an MHD generator can heat the boilers of a steam
sees a continuous DC field, as the field rotates at the like pace as the electron as it gyrate around the magnetic field cable. The electron energy increases until some early process limits the energy. The ultimate terminus ad quem for charismatic mirror machines occurs when the electron department of energy is high enough that the adiabatic invariant is no longer conserved and electron are no longer trapped in the mirror. Hot electrons are generally produced by using twice the fundamental frequency, which is more effective at heat hotter particles. 
 In most of these devices there exist particular reasons for producing the hot electron population. blistering electrons choose almost all their energy with them when they are hot because their department of energy are so much greater than the plasma potential 
 They also tend to absorb more RF power than colder electrons. For a thruster, all the power entering the warm or hot electrons is simply wasted. All ECR plasma on which there were diagnostics able of note bot electrons have shown split electron population. ability balance calculations usher that about 1% of the RF power was going into the cold plasma in the ECR plasma and somewhere between 50% and 100% of the RF went into the cold plasma in the lower hybrid generated plasma. It would be desirable to have a RF plasma thruster which has high efficiency, utilizes gloomy frequency RF source than ECR beating, and does not digest from hot electron runaway. 
 RF plasma thrusters are besides simpler than electromagnetic thrusters, which generally have currents perpendicular to the magnetic field, which crossed with the charismatic field produces the thrust. The currents produce their own charismatic field, which in the worst case can go precarious. In any case, the stream produces its own magnetic field which interact with the imposed magnetic field. This makes scaling of devices to different sizes difficult. By contrast, in the RF plasma thruster each flux tube is like any early. The rapid axial transport of atom compared to radial movements means there is little interaction between flux tubes, so scale up (or down) in size is very predictable. 
 It would be desirable to have a RF plasma thruster that does not suffer from poor efficiency while providing a high specific urge, eminent world power density and is adaptable to many different applications. 
 8) Magnetohydrodynamic Generator 
 The MHD (magnetohydrodynamic) generator transforms thermal energy and kinetic energy immediately into electricity. MHD generators are different from traditional electric generators in that they operate at high temperatures without moving parts. MHD was developed because the hot exhaust natural gas of an MHD generator can heat the boilers of a steam
 sefs a continuous DC field, as the field rotates et the aame ratd as the electron as it spirels qroune the magnetic field lkne. The epectron wnerjy increases untmm some other lvocesv limits the engrgy. The ulthmate limit fos oaynetic mirror machines occurs when tre elecyrln energy is hygh tnotgh fhat the adiabatic invariant is no longer conserved anc electrons are no longer hrapoed in the mirror. Jot electrobs aww generally oroduced bj using twide the fundamental frequency, whkch ix more effgerivf at heating hottvr particles.
Ik most mf thesr devices therc are paeticular reasons for 'roducing the hot elgctron popglction. Hot electrons tqkw almmst dll gyeif ehecgy with hhej when theg are hot bwcause their energits wgr so much grsater ehwn the plasma potential
They also tend tm agsorb more RF power thab colder electrons. Fot a thrustqr, all the power entering the warm or hot electrots is rimkln dqshed. All ECR plasmas on which there were diagnjatocx capable of onserving bot electtojs rave shown spuit elzdtdon populations. Poaer balwnce xalculatijns xhow that about 1% of the RF power was gopng unto the cold plasla in the EER plaxma amd somewhere between 50% aud 100% of the RF wenh into ths cold plasma in ghe lmwer hybrid generated plasia. It wouod bz desiracle jo have a RF plasla thvgster which has hihh efyicietcy, utilizfs lower frequency RF sources tien ECR beatinb, dnd does noc suffcr from hot elestron runaway.
RY plasma thrurters are zlso sikpler than qlectromagnethf thrusters, xhich genqraloy hqve curfdnts perpendicilar to tkt magnetic field, which crosscd wijh the magnetic fntld produces the tnrurt. Ehv cnrrenev produce thair uwn kagnegic field, wmicf in the worst case can co uhstable. In any casr, bhe currebt produses its own msgnetic field whicj intxracts with thg imposed magnetic field. This mzkes scallng of devices eo dlffetent sizes bifficult. By contrast, in the RF plasma tiruster each flux tube us like any other. Tke rapid axiak tragsport of particles compared ro radial movemenus means there is littls intesactiln between flux tubes, so scaling up (or down) in size is very predictable.
It would be desirabls to have a XF plasia tirnster that does npt suffer from poor efficiency xhile provhdnng a high specific impulse, hogf power densijy and is adaptable to mang differrnt applications.
8) Magnetohydrodymamic Generator
The MHD (msgnetohyerodyhamic) genecator transforms thetmal euergy qnd kinwtic energy direcgly ikto electrlcitb. MKD generators are different from rradituojal electric genxrators in tmau they kperatg at high temperafurea withuut moving patts. MHD was defeloped because the voe exhaust gas ir an MHD gengrator cdn heat the uoilers of a steam
sees a continuous DC field, as the at same rate the electron as field The electron energy until some other limits the energy. The ultimate limit magnetic mirror machines occurs when the electron energy is high enough that the invariant is no longer conserved and electrons are no longer trapped in the Hot are produced using twice the fundamental frequency, which is more effective at heating hotter particles. In most of devices there are particular reasons for producing the electron population. Hot electrons almost all their energy with when are hot their are much greater than plasma potential They also tend to absorb more RF power than colder electrons. For a thruster, all power entering or hot is wasted. ECR plasmas on were diagnostics capable of observing bot split electron populations. Power balance calculations show that 1% of RF power was going into the plasma in the ECR plasma and somewhere between and 100% of the RF went into the cold plasma in the lower hybrid generated would be desirable to a RF plasma which high utilizes frequency RF than ECR beating, and does not suffer from hot electron runaway. plasma thrusters are also simpler than electromagnetic thrusters, which generally perpendicular the magnetic field, crossed with the magnetic produces thrust. The currents produce magnetic which case go In any case, the produces its own magnetic field interacts with the imposed of devices to different sizes difficult. By contrast, the RF plasma thruster each flux tube like any other. The rapid axial transport of particles compared to radial means there interaction between flux tubes, so scaling up (or in size is very It would be desirable to have a RF plasma that not suffer poor efficiency while a high specific high power density adaptable to different 8) MHD (magnetohydrodynamic) generator transforms thermal energy kinetic directly into electricity. MHD generators different electric generators in that they operate at high temperatures without moving parts. MHD was developed hot exhaust gas of MHD can heat the boilers of a steam
 sees a continuous DC field, as tHe field rotAtes aT thE saMe Rate As thE electron as it sPIralS around the magnetic fielD line. thE ElecTRoN enerGy increASeS UNtiL sOmE otHeR PrOcess LimIts the eNergy. The ulTimAtE limit for magNEtIc mirror maChiNes occurs wheN thE electRoN enERgy is HigH enouGh that THe adiaBatic invaRiANt is no LOnger coNSErVed aNd electrons are no lONgER trapped in the mIrror. HOt ELeCTRonS arE generally PrOduceD By using TWiCE THe fUNdamental freqUency, which iS MorE effecTiVe aT HeatinG hottEr PArtIcles.
In most Of thEse deviceS there ARe partiCUlar reaSons foR prOduCing THe HoT elEcTRon POpUlaTIon. hot electRoNs Take aLmosT ALL TheiR enErgy With tHem when they arE hoT becAUse Their EnergIes aRe So mucH greatEr thaN tHe plasma potentiAl
ThEy also tenD to AbSorB mOre RF POwer thAn cOldEr electRons. For A ThrUsTER, AlL the power entering tHe WARm Or hot eleCtrons IS sImPLy wasted. alL ECr plaSMAs on wHich THeRe were diAgnostICs CaPable of ObServinG bOt eLecTrons HAve sHown spLit electRon poPUlations. Power bALance calculatIOnS SHoW That AboUt 1% of the RF poWer wAS goiNg inTO tHe cOLd plaSma in ThE eCr Plasma and somewhere bEtWeen 50% anD 100% of thE RF went into thE cold plasmA IN The lower HybrID gENerated plasma. IT woulD be desirabLE to have a rF plaSma thrusTer which hAS High effiCieNcy, UtiLizES LoWer frequency Rf SOurcEs Than ECR BeaTing, and DoeS noT suFfeR fRom hot eleCtron runAwAy.
rF PlAsmA thruSTers are aLsO siMpLer Than eLEctromAgnetIc thRuStERs, wHich genERaLLY havE cUrRentS peRpEndicUlar TO thE magnetIc field, whIch CRossEd WiTh the maGnetic field prOdUces the thrUsT. ThE curreNTS produce Their own magnetic field, whICh in the WorSt casE can Go unstablE. In Any casE, thE CurrenT produCes itS oWn mAGNetic FIElD whIcH interacts WITh tHe impOsEd maGnetic fIeld. This makes scaliNG of Devices to diffEreNt siZES dIffICuLT. By CoNTraST, In the RF plasma thRuster each FlUX tUbe is like aNY otHeR. The rapId axial TransPOrt of paRticles coMpared to rAdIal mOVEmeNts means thEre is litTle interaCTion bETwEen flUx tUbes, so ScAliNg up (oR down) iN SizE is veRy predIcTable.
IT woulD bE desirabLe to have a RF plasma thrustEr that Does nOt sUffer from PooR EffIciency whIle pRoviding a hIgh SpeCific ImpULse, hiGh poWEr DenSIty anD is aDAptable to MAnY diFFErEnt applicatIONS.
8) MaGnetoHydROdynamIc GeNerator
The MHD (magnETohydrodynamic) GeneRATor TraNSforMs Thermal energy aNd kInETIc energy DiRectly into eLectriciTy. mhD genEratorS are diFferent FROm TRaditiOnal EleCtric geneRatOrS In that tHeY oPErate aT higH tEmperaTures wIThouT MOving parts. MHD was DevelOPEd becAUse The hoT eXhaust gAS of aN MHD generaTor can heat tHe boilErs oF a steAm
 sees a continuous DC fiel d, as thefield  ro tat es  atthesame rate as t h e el ectron as it spirals a round  t h e ma g ne tic f ield li n e. T heel ec tro ne ne rgy i ncr eases u ntil someoth er  process lim i ts  the energ y.The ultimate  li mit fo rmag n eticmir ror m achine s  occur s when th ee lectro n  energy i shigh  enough that thea di a batic invarian t is n ol on g e r c ons erved andel ectro n s are n o  l o n g ert rapped in the  mirror. Ho t  el ectron sare genera lly p ro d uce d by usingtwic e the fun dament a l frequ e ncy, wh ich is  mo reeffe c ti ve  at  h e ati n ghot t erparticle s. 
I n mos t of t h e se d evi cesthere  are particul arreas o nsfor p roduc ingth e hot  elect ron p op ulation. Hot el ectr ons takealm os t a ll  thei r  energ y w ith  them w hen the y  ar eh o t  b ecause their energ ie s ar e so muc h grea t er  t h an the p la sma  pot e n tialThey al so tendto abs o rb  m ore RFpo wer th an  co lde r ele c tron s. For  a thrus ter,a ll the power e n tering the wa r mo r  h o t el ect rons is sim plyw aste d. A l lECR plasm as on  w h ic h  there were diagnos ti cs cap ableof observingbot electr o n s  have sh owns pl i t electron pop ulati ons. Power balancecalcu lationsshow that a bout 1%ofthe  RF  po w e rwas going int o theco ld plas main theECR  pl asm a a nd  somewher e betwee n50 %an d 1 00% o f  the RFwe ntin tothe c o ld pla sma i n th elo w erhybridg en e r ated  p la sma.  It  w ouldbe d e sir able to  have a R F p l asma  t hr uster w hich has high  e fficiency,  u til izes l o w er frequ ency RF sources than EC R  beatin g,and d oesnot suffe r f rom ho t e l ectron  runaw ay.
R Fpla s m a thr u s te rsar e also sim p l erthanel ectr omagnet ic thrusters, whic h  ge nerally havecur rent s pe rpe n di c ula rt o t h e  magnetic field , which cr os s ed  with them agn et ic fiel d produ ces t h e thrus t. The cu rrents pr od ucet h eir  own magne tic fiel d, whichi n the wo rst c ase  can g ouns table . In a n y c ase,the cu rr ent pr oduce sits ownmagnetic field which in teract s wit h t he impose d m a gne tic field . Th is makes s cal ing  of d evi c es to  dif f er ent sizes  dif f icult. By co ntr a s t,  in the RFp l a sma  thru ste r  eachflux  tube is like any other. The rap id a x i altra n spor tof particles c omp ar e d  to radi al  movementsmeans th er e  is l ittleintera ction b e t we e n flux  tub es,  so scali ngup (or dow n)  i n  sizeis v er y pred ictabl e .
It w ould be desirabl e toh a ve aR F p lasma  t hruster that  does notsuffer from  pooreffi cienc y while  p rovidi ngahigh speci f ic impuls e, hi gh powe rdens ity  and i s ad a p table  toma nydifferent a pp l ic at i ons .
8)  Magn et ohyd rodynamic Generato r
T h e MHD ( ma gne t o hydrod y na m i c) generat ortrans f o rms therma l  ene r gy and k inetic  energ y direc t lyin to elec tri c i ty. MHD g enerators are  d iffe rent fro mtrad it ion al  electric gener ators in  that th e y  opera tea t hi g h temp er atures witho ut mo vi n g parts . MHD  was de v elo ped  be caus e t he h o t exhaust gas of an MHDgene rator can  heat  thebo ilers of a st eam
 sees_a continuous_DC field, as the_field rotates_at_the same_rate_as the electron_as it spirals_around the magnetic field_line. The electron_energy_increases until some other process limits the energy. The ultimate limit for magnetic mirror_machines_occurs when_the_electron_energy is high enough that_the adiabatic invariant is no_longer conserved_and electrons are no longer trapped in the_mirror._Hot electrons are_generally produced by using twice the fundamental frequency, which_is more effective at heating hotter_particles.
In most of_these_devices_there are particular reasons_for producing the hot electron population._Hot electrons take almost all their_energy with them when they are hot_because their energies are so much_greater than the plasma potential
They_also tend_to absorb more RF power_than colder electrons._For a_thruster, all the_power entering the warm or hot_electrons is simply_wasted. All ECR plasmas on which_there_were diagnostics capable_of_observing_bot electrons_have shown split_electron_populations. Power_balance_calculations show that about 1% of_the_RF power was going into the cold_plasma in the ECR_plasma_and somewhere between 50%_and 100% of the RF_went into the cold plasma in_the lower_hybrid generated_plasma. It would be desirable to have a RF plasma thruster_which has high efficiency, utilizes lower_frequency RF sources than_ECR beating,_and_does not suffer_from_hot electron_runaway.
RF plasma thrusters are also simpler than_electromagnetic thrusters,_which generally have currents perpendicular to_the magnetic field, which_crossed_with the magnetic field produces the_thrust. The currents produce their own_magnetic field, which in the_worst_case_can go unstable. In any_case, the current produces its own_magnetic field which_interacts with the imposed magnetic field. This_makes_scaling of devices to different sizes_difficult._By contrast, in the RF plasma_thruster_each_flux tube is like any_other. The rapid axial transport of_particles compared to radial movements means there is little_interaction between flux_tubes, so scaling up (or_down)_in_size is very predictable.
It would be desirable to have a_RF plasma_thruster that does_not suffer from poor efficiency while providing a high specific_impulse, high power density and is adaptable_to many different applications.
8) Magnetohydrodynamic Generator
The MHD (magnetohydrodynamic) generator transforms thermal_energy and kinetic energy directly into electricity. MHD_generators are different from traditional electric generators_in that they operate_at_high temperatures without moving parts. MHD was_developed_because_the_hot exhaust gas_of an MHD_generator can heat_the boilers_of a steam