Nuclear saw tshuaj tiv thaiv. Tej yam kev mob ntawm lub nuclear saw tshuaj tiv thaiv

Lub hom phiaj ntawm Relativity hais tias loj - yog ib tug tshwj xeeb daim ntawv ntawm lub zog. Los ntawm no nws hais ntxiv hais tias nws yog ua tau los hloov loj mus ua lub zog thiab lub zog mus rau hauv loj. Nyob rau intraatomic theem, xws tshua coj qhov chaw. Nyob rau hauv kev, ib txhia ntawm qhov loj ntawm lub atomic nucleus yuav zoo tig mus ua zog. Qhov no tshwm sim nyob rau hauv ob peb txoj kev. Ua ntej, cov tub ntxhais yuav ua txhaum li mus rau hauv ib tug xov tooj ntawm me me nuclei, tshuaj tiv thaiv no yog hu ua "lub cev qhuav dej". Secondly, me tsuab tau yooj yim cuag kom tau loj - qhov no synthesis cov tshuaj tiv thaiv. Nyob rau hauv lub qab ntuj khwb, xws tshua yog tsis yooj yim dua. Suffice nws hais tias lub fusion cov tshuaj tiv thaiv - ib qhov chaw ntawm lub zog rau lub hnub qub. Tab sis cov tshuaj tiv thaiv kev lwj uas siv los ntawm noob neej mus nuclear reactors, raws li tus neeg tau kawm los tswj cov complex dab. Tab sis li cas yog ib tug nuclear saw tshuaj tiv thaiv? Yuav ua li cas tswj tau nws?

Yuav ua li cas tshwm sim nyob rau hauv lub nucleus ntawm ib tug atom

Nuclear saw tshuaj tiv thaiv - ib tug txheej txheem khiav nyob rau hauv collisions ntawm elementary hais los yog nuclei nrog rau lwm cov nuclei. Yog vim li cas yog ib tug "saw"? Cov teeb no ntawm tshwm sim los muaj ib zaug xwb nuclear tshua. Raws li ib tug tshwm sim ntawm txoj kev no muaj kev pauv ntawm quantum xeev nucleon thiab muaj pes tsawg leeg nyob rau hauv lub noob pob kws, tshwm sim tej yam tshiab hais - cov khoom ntawm cov tshuaj tiv thaiv. Nuclear saw tshuaj tiv thaiv, cov physics uas tso cai rau koj mus tshawb cov mechanisms kev sis raug zoo ntawm cov nuclei nrog lub nuclei thiab hais - cov thawj txoj kev rau zus tau tej cov tshiab hais thiab isotopes. Nyob rau hauv thiaj li yuav to taub lub saw tshuaj tiv thaiv, peb yuav tsum xub hais nrog cov tib.

Yuav ua li cas yuav tsum tau rau cov tshuaj tiv thaiv

Nyob rau hauv thiaj li yuav siv xws txheej txheem, raws li cov nuclear saw tshuaj tiv thaiv, nws yog tsim nyog los coj ua ke tus hais (tub ntxhais thiab nucleon ob cores) nyob rau hauv qhov kev ncua deb ntawm lub vojvoog ntawm muaj zog sis (kwv yees li ib Fermi). Yog hais tias lub mus yeej loj, tus sis ntawm them hais yog purely Coulomb. Nyob rau hauv lub nuclear cov tshuaj tiv thaiv, nyob rau hauv raws li nrog tag nrho cov kev cai: txuag ntawm lub zog, lub sij hawm ntawm momentum, baryon xwb. Nuclear saw tshuaj tiv thaiv yog denoted los ntawm cov cim ib tug, b, ib tug, d. Cim ib tug qhia ib tug pib tub ntxhais, b - qhov teeb meem particle, nrog - ib tug tshiab tawm txim liab hais, thiab d qhia lub resultant tub ntxhais.

lub zog ntawm cov tshuaj tiv thaiv

Cov saw nuclear cov tshuaj tiv thaiv yuav muab qhov chaw nrog ob lub haum thiab tso tawm ntawm lub zog, uas yog ncaj rau tus loj sib txawv ntawm hais tom qab cov tshuaj tiv thaiv thiab ua ntej nws. Lub absorbed zog thiab txiav txim seb qhov tsawg kawg nkaus kinetic zog ntawm ib tug kev sib tsoo, ib tug thiaj li hu ua lub chaw pib nuclear cov tshuaj tiv thaiv nyob rau hauv uas nws yuav ntws dawb do. Qhov no pib nyob rau hauv lub hais tias koom rau hauv lub sis, thiab nyob rau lawv cov yam ntxwv. Thaum thawj zaug rau theem, tag nrho cov hais yog nyob rau hauv ib tug predetermined quantum lub xeev.

reacting

Lub ntsiab qhov chaw ntawm them hais tias bombard lub nucleus yog lub particle tsuj roj, uas tso cai rau kab teeb ntawm protons, hnyav ions thiab lub teeb nuclei. Qeeb neutrons ua los ntawm kev siv ntawm nuclear reactors. Rau kho ntawm qhov teeb meem them hais yuav siv tau ntau hom nuclear tshua - ob lub synthesis thiab hniav lwj. Qhov ntau yam ntawm lawv nyob rau qhov tsis muaj tus hais tau hais tias tsoo. Los ntawm no ntau yam yog txuam xws li ib tug yam ntxwv, tus ntoo khaub lig seem ntawm cov tshuaj tiv thaiv - tus nqi ntawm cov zoo cheeb tsam uas characterizes cov tub ntxhais raws li ib lub hom phiaj rau qhov teeb meem hais thiab uas yog ib qho kev ntsuas ntawm qhov yuav tshwm hais nkag mus rau lub nucleus thiab INTERACTIONS. Yog hais tias qhov tshuaj tiv thaiv yog kawm hais nrog ib tug nonzero kiv nqi, cov seem yog ncaj qha nyob rau lawv orientation. Txij li thaum lub rov qab ntawm cov khoom hais tsis taw qhia kom paub kiag li cia li, thiab ntau dua los yog tsawg yaam yam, tag nrho cov corpuscles yog polarized. Ntau characterization ntawm lub spin-taw qhia kom paub qhia txog cov polarization vector.

Cov tshuaj tiv thaiv mechanism

Yuav ua li cas yog ib tug nuclear saw tshuaj tiv thaiv? Raws li twb tau hais, nws yog ib tug sib lawv liag ntawm yooj yim tshua. Paub meej txog qhov teeb meem particle thiab nws cov sis raug zoo nrog cov tub ntxhais yog nyob rau hauv lub loj, them nyiaj, ib tug kinetic zog. Sis txiav txim los ntawm cov neeg kawm ntawv txoj kev ywj pheej ntawm lub nuclei, uas yog tus pog thaum muaj kev sib tsoo. Nkag mus rau hauv tag nrho cov tswj cov mechanisms tso cai rau ib tug txheej txheem xws li tshuaj nuclear saw tshuaj tiv thaiv.

direct tshua

Yog hais tias ib tug them particle uas hits lub hom phiaj nucleus, cia li nphav nws, lub duration ntawm lub kev sib tsoo yog tseem tsim nyog los mus kov yeej lub nuclear voos kheej-kheej deb. Qhov no nuclear cov tshuaj tiv thaiv yog hu ua ncaj. Ib tug ntau yam ntxwv rau tag nrho cov tshuaj ntawm no hom yog qhov pib ntawm ib tug me me muaj pes tsawg tus ntawm degrees ntawm txoj kev ywj pheej. Nyob rau hauv tus txheej txheem no, tom qab thawj zaug kev sib tsoo particle muaj tseem txaus lub zog kom kov yeej lub nuclear attraction. Piv txwv li, xws kev sib tshuam, raws li cov inelastic neutron scattering, them pauv, thiab yog ncaj. Cov pab ntawm xws dab nyob rau hauv tus yam ntxwv hu ua "tag nrho cov ntoo khaub lig seem" heev tu siab heev. Txawm li cas los, cov khoom faib rau kab dua nuclear cov tshuaj tiv thaiv los mus txiav txim qhov yuav tshwm ntawm emission ntawm lub kaum sab xis ntawm lub beam kev taw qhia, quantum tooj selectivity populated lub xeev thiab los mus txiav txim lawv cov qauv.

pre-equilibrium emission

Yog hais tias lub particle tsis tawm hauv lub teb ntawm nuclear kev koom tes tom qab thawj zaug kev sib tsoo, nws yuav tsum tau muab kev koom tes nyob rau hauv ib tug cascade ntawm successive collisions. Qhov no yog ua tau raws nraim li cas yog hu ua tus nuclear saw tshuaj tiv thaiv. Raws li ib tug tshwm sim, xws li ib tug teeb meem no rau hauv lub kinetic zog ntawm tus hais yog faib ntawm cov kev tivthaiv qhov chaw ntawm lub ntsiav. Tus heev tib lub xeev ntawm cov keeb yuav maj mam ua ntau npaum li cas complicated. Thaum lub sij hawm tus txheej txheem no ntawm tej nucleon los yog tag nrho pawg (pab pawg neeg ntawm nucleons) zog yuav tau teem, nws yog txaus rau cov emission ntawm ib tug nucleon los ntawm lub keeb. Ntxiv so yuav ua nyob rau hauv ib tug statistical equilibrium thiab tsim los ntawm ib tug compound nucleus.

saw tshua

Yuav ua li cas yog ib tug nuclear saw tshuaj tiv thaiv? Qhov no ib theem zuj zus ntawm nws constituent qhov chaw. Xws li ntau sib law liag tib nuclear tshua tshwm sim los ntawm them hais yuav tshwm sim li cov tshuaj tiv thaiv cov khoom nyob rau hauv lub kauj ruam dhau. Yuav ua li cas yog hu ua ib tug nuclear saw tshuaj tiv thaiv? Piv txwv li, fission ntawm hnyav nuclei, thaum muaj ntau fission cov txheej xwm chiv tau los ntawm yav dhau los decays neutrons.

Nta ntawm ib tug nuclear saw tshuaj tiv thaiv

Ntawm tag nrho cov tshuaj tshua nws tau txais ntau muab faib rau cov saw. Hais nrog tsis siv sib txuas ua kom tiav lub luag hauj lwm ntawm dawb radicals los yog atoms. Nyob rau hauv tus txheej txheem no, raws li cov nuclear saw tshuaj tiv thaiv, tus mechanism ntawm nws cov hoob kawm muab neutrons uas muaj lub Coulomb barrier thiab siab lub nucleus raws li qhov haum. Yog hais tias qhov nruab nrab zoo nkaus li tsim nyog particle, nws ua ib cov saw ntawm tom ntej transformations, uas yuav mus txuas ntxiv los saw scission vim txoj kev poob ntawm cov cab kuj hais.

Yog vim li cas poob cab kuj

Tsuas muaj ob yog vim li cas vim txoj kev poob ntawm cov cab kuj hais tas mus li saw tshua. Tus thawj yog qhov haum ntawm tus hais tsis muaj theem nrab emission txheej txheem. Qhov thib ob - tawm hauv tus hais nyob rau hauv lub Scope ntawm cov tshuaj yeeb dej caw uas txhawb nqa cov saw txheej txheem.

Ob hom txheej txheem

Yog hais tias lub chav tsev yog yug los thiaj tau tuaj particle cab kuj nyob rau hauv txhua lub sij hawm saw tshuaj tiv thaiv, ces tus txheej txheem no yuav raug hu ua unbranched. Nws yuav tsis ua rau qhov kev tso tawm ntawm lub zog nyob rau hauv ib tug loj scale. Yog hais tias muaj ntau ntau yam cov cab kuj hais, nws yog hu ua ib tug branched cov tshuaj tiv thaiv. Yuav ua li cas yog ib tug nuclear saw tshuaj tiv thaiv uas branching? Ib tug tau txais nyob rau hauv lub yav dhau los ua los ntawm kev theem nrab hais ntxiv pib ua ntej lub saw, tab sis lwm tus yuav tsim tshiab tshua uas yuav ceg tawm. Nrog rau qhov no yuav tsum sib tw dab ua rau breakage. Cov uas ua teeb meem no yuav muab ntxiv rau kev tseem ceeb heev thiab marginal phenomenon. Piv txwv li, yog tias lub laaj ntawm ntau tshaj purely tshiab chains, cov tshuaj tiv thaiv nws tus kheej-kev pab txhawb nqa yog tsis yooj yim sua. Txawm hais tias muaj siab nws artificially qhia mus rau hauv lub nruab nrab yam naj npawb ntawm cov hais, tus txheej txheem tseem yuav ploj thaum lub sij hawm (feem ntau yog heev sai sai). Yog hais tias cov xov tooj ntawm cov tshiab chains yuav tshaj cov xov tooj ntawm so, cov saw hlau tshuaj tiv thaiv yuav pib kis tau thoob plaws cov khoom.

ib qho tseem ceeb lub xeev

Ib qho tseem ceeb thaj av ntawd yog sib cais mob lub xeev ntawm teeb meem tshaj nws tus kheej-phem tshaj saw tshuaj tiv thaiv thiab hauv lub cheeb tsam nyob qhov twg no cov tshuaj tiv thaiv yog tsis tau ntawm tag nrho cov. Qhov no parameter yog yus muaj los ntawm koob pheej ntawm lawv nyob nruab nrab ntawm tus xov tooj tshiab circuits thiab cov xov tooj uas tau so. Raws li hauv lub xub ntiag ntawm lub particle-free cab kuj tseem ceeb heev lub xeev yog lub ntsiab yam khoom nyob rau hauv ib daim ntawv teev raws li "tej yam kev mob ntawm lub nuclear saw tshuaj tiv thaiv." Achievement ntawm tus mob no yuav tsum tau txiav txim los ntawm ib tug xov tooj uas tau yam. Faib hnyav lub caij nucleus yog zoo siab heev los tsuas yog ib qho neutron. Raws li ib tug tshwm sim ntawm txoj kev no, raws li ib tug saw tshuaj tiv thaiv ntawm nuclear fission, muaj ntau ntau cov neutrons. Thiaj li, tus txheej txheem no tej zaum yuav tsim branched cov tshuaj tiv thaiv uas muaj thiab neutrons yuav ua. Nyob rau hauv lub rooj plaub uas tus nqi ntawm neutron captures tsis muaj division los yog departures (tsis nqi) yuav tsum compensated ceev tu tub tu kiv cab kuj hais, cov saw hlau tshuaj tiv thaiv yuav mus nyob rau hauv ib tug nyob ruaj ruaj hom. Qhov no kab zauv qhia txog cov kev ua lej khu tau. Nyob rau hauv rooj plaub no nws yog sib npaug zos rau kev sib sau saum toj no. Nyob rau hauv nuclear fais fab vim cov kev taw qhia ntawm tsis zoo tswv yim ntawm tus nqi ntawm lub zog tso tawm thiab cov kev ua lej khu tau yuav pom tau hais kev tswj ntawm nuclear kev tig cev. Yog hais tias qhov no piv ib yam li ib tug, ces cov tshuaj tiv thaiv yuav tsim exponentially. Tsis ceev faj saw tshuaj tiv thaiv siv nyob rau hauv nuclear riam phom.

Nuclear saw tshuaj tiv thaiv nyob rau hauv lub zog sector

Lub reactivity ntawm cov reactor yog txiav txim los ntawm ib tug loj tus naj npawb ntawm dab uas coj qhov chaw nyob rau hauv nws cov active tsam. Tag nrho cov influences yog txiav txim los ntawm lub thiaj-hu ua coefficient ntawm reactivity. Cawv ntawm kub kev hloov ntawm graphite rods, coolants los yog uranium reactivity ntawm cov reactor thiab cov kev siv ntawm cov percolation txheej txheem xws li ib tug nuclear saw tshuaj tiv thaiv, tsiag ntawv los ntawm kub coefficient (rau cov coolant, uranium, nyob rau graphite). Muaj kuj yog ib tug nyob tos ntawm cov yam ntxwv ntawm lub hwj chim, raws li barometric ntsuas ntawm chav tsis. Kom muaj lub nuclear cov tshuaj tiv thaiv nyob rau hauv lub reactor tsim nyog hloov ib lub caij mus rau lwm lub. Rau qhov no nws yog tsim nyog los noj mus rau hauv tus account lub flow tej yam kev mob ntawm lub nuclear saw tshuaj tiv thaiv - cov muaj ntawm ib yam khoom uas yog tau faib thiab faib rau lawv tus kheej los ntawm cov hniav lwj los ntawm ib tug xov tooj ntawm elementary hais uas, raws li ib tug tsim nyog tau, yuav ua rau tus so ntawm lub division cores. Raws li xws li ib tug yam khoom uas yog feem ntau siv uranium-238, uranium-235, plutonium-239. Thaum lub sij hawm tso cai ntawm lub nuclear chain reaction isotopes ntawm cov ntsiab yuav tawg ua me me thiab tsim ob los yog ntau tshaj lwm yam tshuaj. Nyob rau hauv tus txheej txheem no, nws yog tawm txim liab thiaj li hu ua "gamma" -rays, ib tug intensive zog tso, yog tsim nyob rau ob los yog peb neutrons muaj peev xwm ua mus ntxiv cov tshuaj tiv thaiv. Paub qhov txawv ntawm qeeb thiab ceev ceev neutrons, vim hais tias nyob rau hauv thiaj li yuav atom tus nucleus disintegrated, cov hais yuav tsum ya ntawm ib yam ceev.