
nyootron cross sekshan

nuclear physixil, oru nyootron cross sekshan enna ashayam oru insidant neutron taargett nucleus thammilulla prathipravartthanatthinte saadhyatha prakadippikkaan upayogikkunnu. nyootron cross sekshan yehbe sem. mee. 2-leeii vistheernnamaayi nirvachikkaam, ithinaayi nadakkunna nyootron-nucley prathikaranangalude ennam pradeshathiloode kadannupokunna insidant neutronukalude ennathinteyum taargett nucleusinte ennathinteyum gunanafalathinu thulyamaanu. nyootron flexumaayi samyojichu, prathikarana nirakk kanakkakkaan ithu prapthamaakkunnu, udaaharanathinu oru aanavorja nilayathinte thapashakthi nedunnathinu. cross sekshan alakkunnathinulla staanderd yoonit 10−28 meter2 allengil 10−24 centimeter2 nuu thulyamaaya kalappurayaan. nyootron cross sekshan valuthaayirikkumbol, oru nyootron nucleusumaayi prathikarikkanulla saadhyatha kooduthalaanu.
oru isotopine (allengil nucleid) athinte nyootron cross section oru insidant neutroninode athu engane prathikarikkunnu ennathum anusarichu tharamthirikkaam. nyootron agiranam cheyyukayum neutronine athinte nucleusil nasippikkukayo nilanirthukayo cheiyunna nucleidukal nyootron agiranam cheiyunnavayaanu, aaa prathikaranatthinu oru "capture cross sekshan" undaakum. vighadanathinu vidheyamaakunna isotopukal vighadanakshamamaaya indhanangalaanu, avaykku anubandhamaaya "vighadana cross sekshan" undu. bakkiyulla isotopukal neutronine chitharikkukayum oru "skaattar cross sekshan" undaakukayum cheyyum. euranium-238 polulla chila isodoppukalkku moonninteyum poojyamallaatha cross sekshanukal undu.
valia skaattar cross section kuranja pindavumulla isotopukal nalla nyootron moderatorukalaanu (chuvadeyulla chart kaanuka). valia agiranam cross sekshanulla nucleidukal vighadippikkukayo kshayikkukayo cheiyunnillenkil avaa nyootron vishangalaanu. deerghakaalaadisthaanathil athinte prathipravartthanam niyanthrikkunnathinum athinte shutdown marjin mechappeduthunnathinuma oru nuclear reactoril manappoorvvam cherkkunna oru vishathe "kathikkaavunna" visham ennu vilikkunnu.
palishayude maanadandangal.
nyootron cross section athinaal nyootron-nucleus prathipravartthanatthinte saadhyathayum aasrayichirikkunnu
oru paridhivare, inipparayunnavayil
taargett tharam aashrithathvam.
oru nischitha tharam taargett kanikaykku nyootron cross sekshan nirvachikkappedunnu. udaaharanathinu, dutarium 2echinte capture cross sekshan saadhaarana hydrajan 1echinekkaal valare cheruthaanu. chila reactors saadhaarana laghuvallathinu pakaram (hydrajante bhooribhaagavum dutarium ulla) bharameriya vellam moderatoraayi upayogikkunnathinte kaaranam ithaanu maadhyamathinullil pidichedukkunnathiloode kurachu neutronukal nashtappedunnu, athinaal sambushtamaaya yureniyathinu pakaram prakrithidatha euranium upayogikkaan ithu prapthamaakkunnu. ithaanu kandu reactorinte thathwam.
prathikarana aashrithathvathinte tharam.
oru insident neutron taargett nuclide thammilulla prathipravartthanatthinte saadhyatha, prathikaranatthinte tharatthil ninnu swathanthramaayi, motham cross sekshan "σ" t "yude sahaayathode prakadippikkunnu. ennirunnaalum, incoming kanika lakshyathil ninnu kuthikkunnundo (athinaal prathipravartthanathinu sesham sanjarikkunnathu thudaruka) allengil prathikaranatthinu sesham aprathyakshamaakumo ennu arian ithu upayogapradamaakum. ekkaaranathaal, chitharalum agiranam cheyyalum cross sekshanukal "σ" kall, "σ" a enniva nirvachikkappedunnu, motham cross sekshan rund bhagika cross sekshanukalude aakethuka maathramaanu
obsorption cross sekshan.
nuclydine sameepikkumbol nyootron agiranam cheyyappedukayaanenkil, aattomik nucleus isodoppukalude pattikayil oru sthaanathu mukalilekku neengunnu. udaaharanathinu, nucleus valareyadhikam oorjjaswalamaanennu soochippikkunna * ulla 235u 236 * u aayi maarunnu. eee oorjjam purathuvidukayum niravadhi samvidaanangaliloode release nadakkukayum venam.
cross sekshan chitharunnu.
scattering cross-sekshane koherant scattering, incoherant scattering enningane veendum vibhajikkaam, ithu scattering cross-sekshante spin aashrithathvam moolavum oru swaabhaavika saambilinaayi, saambilil ore moolakatthinte vyathyastha isodoppukalude saannidhyavum moolamaanu.
neutronukal nuclear pottanshyalumaayi samvadikkunnathinaal, scattering cross sekshan gadakathinte vyathyastha isodoppukalkku vyathyaasappedunnu. hydrajan athinte isotope duteriavum valare pradhanappetta oru udaaharanamaanu. hydrajante motham cross sekshan deuteriyathinte 10 madangu kooduthalaanu, kooduthalum hydrajante valia poruthappedaattha chitharal neelam kaaranam. chila lohangal neutronukalkku suthaaryamaan, aluminium, syrconium enniva ithinu rund mikacha udaaharanangalaan.
aakasmika kanika oorjja aashrithathvam.
oru nischitha lakshythinum prathikaranatthinum, cross sekshan nyootron vegathaye shakthamayi aasrayichirikkunnu. angeyattatthe saahacharyathil, cross sekshan kuranja oorjjathil poojyamo (cross sekshan praadhaanyamulla oorjjathe threashold oorjjam ennu vilikkunnu) allengil uyarnna oorjjathekkaal valare valutho aakam.
athinaal, oru cross sekshan oru nischitha oorjjathil nirvachikkanam allengil oru oorjja paridhiyil (allengil group) sharashari aayirikkanam.
udaaharanathinu, euranium-235-nte vighadana cross sekshan uyarnna nyootron oorjjathil kuravaanennum ennaal kuranja oorjjathil kooduthalaanennum valathuvashathulla plott kaanikkunnu. atharam bhauthika parimithikal vishadeekarikkunnathu enthukondaanu mikka pravarthanakshamamaaya nuclear reactorukalum neutroninte oorjjam kuraykkunnathinu oru nyootron moderator upayogikkunnathu, angane oorjjam uthppaadippikkunnathinum shringhala prathikaranam nilanirthunnathinum athyanthaapekshithamaaya vighadana saadhyatha vardhippikkunnu.
eathenkilum tharatthilulla cross sekshante oorjja aashrithathvathekkurichu lalithamaaya kanakk nalkunnathu ramsover modalaan, ithu oru neutroninte "phalapradamaaya" valuppam nyootron undakaan saadhyathayulla sthalathinte probability density functionte veethiykk aanupaathikamaanu enna ashayathe adisthaanamaakkiyullathaanu, ithu thanne neutroninte thermal dii broggy tharamgadairkhyathinu aanupaathikamaanu.
neutroninte phalapradamaaya aaram enna formula _ 3 edukkumbol, nyootranukal phalapradamaaya aaram formula _ 5-nte nucleusukalil adikkunna vritha soothravaakyam _ 4-nte vistheernnam namukk kanakkakkaam.
eee maathrkayude anumanangal nishkalankamaanenkilum, nyootron agiranam cross sekshante saadhaarana alakkunna oorjja aashrithathvathenkilum ithu gunaparamaayi vishadeekarikkunnu. aattomik nucleusinte (1-10 fm, e = 10-1000 kev) soothravaakyam _ 7 ennathinekkaal valare valia tharamgadairkhyamulla neutronukale avaganikkaam. eee kuranja oorjja neutronukalkku (taapa neutronukal polullava) cross sekshan formula _ 8 nyootron vegathaykku vipareeta anupaathathilaanu.
fission nuclear reactorukalil nyootron moderator upayogikkunnathinte prayojanam ithu vishadeekarikkunnu. maruvashathu, valare uyarnna oorjjamulla neutronukalkku (1 meviyil kooduthal), formula _ 9 avaganikkappedaam, nyootron cross sekshan ekadesham sthiramaanu, ithu aattomik nucleusinte cross sekshan maathram nirnnayikkunnu.
ennirunnaalum, eee lalithamaaya maathruka nyootron anurananm ennu vilikkappedunnava kanakkiledukkunnilla, ithu 1 ivi-10 kevi oorjja paridhiyile nyootron cross sekshane shakthamayi parishkkarikkunnu, chila aanava prathikaranangalude threashold oorjjavum.
thapanilaye aashrayikkuka.
cross sekshanukal saadhaaranayaayi 20 digri selshyasilaanu alakkunnathu. maadhyamathinte thapanilaye aashrayikkunnath (athaayath. lakshyam), inipparayunna soothravaakyam upayogikkunnu
ivide "σ" ennathu "t" thaapanilayile cross section "σ" 0 ennathu "t" 0 thaapanilayile cross sekshanumaanu (kelvinukalil "t", "t" 0).
neutroninte ettavum saadhyathayulla oorjjathilum vegathayilumaanu oorjjam nirvachikkappedunnathu. nyootron janasamkhyayil oru maxwellian vitharanam adangiyirikkunnu, athinaal sharashari oorjjavum vegathayum kooduthalaayirikkum. thalphalamaayi cross-sekshan samavaakyam 38 kanakkaakkumbol oru maxwellian thiruthal padam ρπ ulppeduthendathundu.
doppler vipuleekaranam.
nyootron anurananakalude doppler vipuleekaranam valare pradhanappetta oru prathibhaasamaan, ithu nuclear reactorinte sthiratha mechappeduthunnu. nuclear doppler prabhavam kaaranam mikka taapa reactorukaludeyum pettennulla thaapanila gunakam negatteevu aanu. thaporjjam (thaapanila) kaaranam nirantharam chalanatthilulla aattangalilaan nucleusukal sthithicheyyunnathu. eee taapa chalanangalude falamaayi, oru lakshyathil imping cheiyunna neutronukal lakshyathile nucleusukalkku oorjjathil thudarchayaaya vyaapanam undennu thonnunnu. ithu, anuranatthinte nireekshicha aakruthiye badhikkunnu. nucleus vishramikkumbolekkaal anurananm cheruthum vishaalavumaan.
thaapanilaykkanusarichu anurananakalude aakruthi maarunnundengilum, anuranathinu keezhilulla motham vistheernnam adisthaanaparamaayi sthiramaayi thudarunnu. ennaal ithu sthiramaaya nyootron agiranam cheiyunnathine soochippikkunnilla. anurananm nilanilkkunna sthiramaaya vistheernnam undaayirunnittum, agiranam nirnnayikkunna oru anurananm avibhaajyaghadakam, vardhichuvarunna thaapanilaykkoppam vardhikkunnu. ithu theerchayaayum k enna gunakam kuraykkunnu (negatteevu reactivity cherkkunnu).
prathikarana nirakkilekkum vyaakhyaanathilekkum link cheyyuka.
oru golaakrithiyilulla lakshyavum (chithratthil chaaraniratthilum chuvappilum ulla vrithamaayi kaanichirikkunnu) lakshyathinte dishayil "v" (neelayil vekttar) vegathayil "parakkunna" kanangalude oru kiranavum (neelayil) sangalppikkuka. dii "tii" samaya edavelayil ethra kanikakal athine baadhikkunnuvenn arian njangal aagrahikkunnu. ithu nedunnathinu, kanikakal chithratthile pacha silindarilaayirikkanam (vooliyam "vii"). silindarinte adisthaanam beam (uparithalam "σ" chuvappil) nuu lambamaayi lakshyathinte jyaamitheeya cross section athinte uyaram d "t" (neelam "v" d "t") samayat kanikakal sanjarikkunna neelavumaanu
n" ennathu oru yoonit voliyathile kanangalude ennamaanennu kanakkiledukkumbol, voliyathil "v" ennathil "n v" kanikakal undu, avaa "v" ennathinte nirvachanamanusarichu oru prathikaranatthinu vidheyamaakum. oru lakshyathilekkulla prathikarana nirakk "r" ennu soochippikkumbol, athu nalkunnu
ithu nyootron flexinte nirvachanathil ninnu nerittu pinthudarunnu
oru yoonit voliyathinu "n" lakshyangalallathe mattonnillenn karuthuka, oru yoonit voliyathinu prathikarana nirakk "r" ithaanu
saadhaarana nuclear aaram "r" 10−12 centimeter kramatthilaanennu ariyumbol, prathekshikkunna nuclear cross sekshan "πr" 2 allengil ekadesham 10−24 centimeter 2 kramathilaayirikkum (angane kalappurayude nirvachanathe nyaayeekarikkunnu). ennirunnaalum, pareekshanaathmakamaayi alakkukayaanengil ("σ" = "r"/("φn")), pareekshanathmaka cross sekshanukal valareyadhikam vyathyaasappedunnu. udaaharanathinu, (n, γ) prathikaranam agiranam cheiyunna mandagathiyilulla neutronukalkku chila sandarbhangalil cross sekshan (senon-135) 2,650,000 kalappurakalkku thulyamaanu, athesamayam gamma-reey agiranam vazhi parivarthanatthinulla cross sekshanukal 0.001 kalappurayude sameepathaan (kooduthal udaaharanangalund).
nuclear cross sekshan" ennu vilikkappedunnathu thalphalamaayi eee lalithamaaya mechanical modalumaayi poruthappedaan nucleus ethra valuthaanennu prathinidheekarikkunna oru poornnamaayum aashayaparamaaya alavaanu.
thudarchayaayathum sharashari cross section.
cross sekshanukal incoming kanika vegathaye shakthamayi aasrayichirikkunnu. onniladhikam kanika vegathayulla oru beam undengil, prathikarana nirakk "r" oorjjathinte muzhuvan shreniyilum samyojippichirikkunnu
ivide "σ" ("e") ennathu thudarchayaaya cross sekshan, "φ" ("e") deferential fluxes, "n" ennathu taargett aattam density.
mono energetic kesinu thulyamaaya oru formulation labhikkunnathin, oru sharashari cross sekshan nirvachikkappedunnu
integral fluxes evideyaanu?
integral fluxes "φ", sharashari cross sekshan "σ" ennivayude nirvachanam upayogichu, munbathe athe formulation kaanapedunnu
microscopic vezhsas macroscopic cross sekshan.
ithuvare, eee lekhanathil paraamarshichirikkunna cross sekshan microscopic cross sekshan "σ" maayi poruthappedunnu. ennirunnaalum, oru yoonit voliyathil ellah taargett kanangaludeyum motham "thulyamaaya vistheernnam" anusarikkunna macroscopic cross sekshan "σ" nirvachikkaan kazhiyum
ivide "n" ennathu lakshyathinte aattomik saandrathayaanu.
athinaal, cross sekshan sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar sentar seen
swatantra paatha ennaanu ardham.
oru kramarahita kanikayude sharashari swatantra paatha "λ" ennathu rund edapedalukal thammilulla sharashari dairkhyamaanu. oru vooliyam "divi" yill "didi" enna samaya edavelayil sanjarikkunna aswasthamallaatha kanangalude motham neelam "ell" ennathu eee samayat oro kanikayum eee volyathile "enn" kanangalude ennathode moodunna "ell" neelatthinte gunanafalamaannu
v" ennathu kanangalude vegathayum "n" ennathu oru yoonit voliyathil kanangalude ennavumaanu
athu thaazhepparayunnavayaanu
nyootron flexinte nirvachanam upayogichu "φ"
athu thaazhepparayunnavayaanu
ennirunnaalum eee sharashari neelam "l" thadassamillaatha kanangalkk maathrame saadhuthayulloo. prathipravartthanangal kanakkiledukkumbol, oro koottiyidikkum edayilulla sharashari dairkhyam labhikkunnathin "λ" ennathine "r" enna motham prathikaranangalude ennathaal harikkunnu
ithil ninnu
athu thaazhepparayunnavayaanu
ivide "λ" ennathu sharashari swatantra pathayum "σ" ennathu macroscopic cross sekshanumaanu.
nakshatrangalkkullil.
hydrajan fusionaayi isodoppukalude pattikayil 8lii, 12bii enniva swaabhaavika stopping pooyintukal roopappeduthunnathinaal, uyarnna moolakangalellaam uyarnna samyojana kramangal prabalamaaya valare choodulla nakshathrangalilaan roopappedunnathennu vishwasikkappedunnu. sooryaneppolulla oru nakshatram prathikaranangalude oru parambarayiloode lalithamaaya 1h-neey 4he-lake samyojippichu oorjjam uthppaadippikkunnu. akathe coor athinte 1 manikkoor indhanam theerkkumbol, suuryan churungukayum 4 vare athinte coor thaapanila cheruthaayi vardhippikkukayum cheyyum ennu vishwasikkappedunnu. shudhamaaya 4eiii fusion 8bailake nayikkunnu, athu 2 4echilekku kshayikkunnu; athinaal 4eiii svayam kooduthalo kuravo valuppamulla isodoppukalumaayi samyojippichu oorjjam uthppaadippikkunna prathikaranatthinu kaaranamaakanam. 4heey 2echumaayi allengil 3echumaayi samyojippikkumbol, athu yathaakramam 6lii, 7lii ennee sthirathayulla isotopukal roopappeduthunnu. hydrajan, healium, lythium isotopukal thammilulla samanamaaya prathikaranangaliloode 8lii, 12sii ennivaykkidayilulla uyarnna oordar isotopukal samanvayippikkappedunnu.
saadhaarana cross sekshanukal.
thazhepparayunnavayil, oru nuclear reactoril praadhaanyamulla chila cross sekshanukal nalkiyirikkunnu. thermal cross sekshan oru maxwellian spectrum upayogichaanu sharashari cheiyunnathu, euranium-235 fission spectrum upayogichaanu phaast cross sekshan sharashari cheiyunnathu. jaani software upayogichu jeff-3.1.1 libraryil ninnaan cross sekshanukal eduthathu.