Cov kev cai lij choj ntawm tej lwj

Lub cev kev cai lij choj ntawm tej lwj twb formulated tom qab lub 1896 Becquerel sab phenomenon ntawm radioactivity. Nws yog unpredictable hloov nuclei ntawm ib co hom lwm, thiab lawv emit ntau hom ntawm hluav taws xob thiab hais hais. Cov txheej txheem tshwm sim lawm, thaum pom los ntawm lawm tab isotopes thiab dag, nyob rau hauv cov ntaub ntawv ntawm tau txais cov nyob rau hauv nuclear kev tig cev. Cov tub ntxhais uas yog muab faib, nws yog suav hais tias yog leej niam, tab sis nws muab tawm - ib tug subsidiary. Nyob rau hauv lwm yam lus, qhov yooj yim txoj cai ntawm tej lwj muaj xws li arbitrary ntuj txheej txheem ntawm converting ib cov tub ntxhais mus rau lwm lub.

Txoj kev tshawb no qhia lub xub ntiag ntawm Becquerel uranium ntsev yav tas los tsis paub hais tias tawg, uas muaj feem xyuam rau lub yees duab phaj, yog lawm ua tus sau nrog huab cua ions thiab muaj ib tug cuab yeej kis tau los ntawm nyias hlau phaj. Lub thwmsim ntawm M. Pierre Curie thiab radium thiab polonium paub tseeb hais tias tus ntsoos ntsoos, raws li tau piav saum toj no, thiab nyob rau hauv science, ib cov tswvyim tshiab, hu ua cov lus qhuab qhia ntawm hluav taws xob.

Qhov no kev tshawb xav, uas qhia cov kev cai lij choj ntawm tej lwj, yog raws li nyob rau hauv lub assumption ntawm ib tug txawj, uas yog kev kawm mus rau statistics. Txij li thaum ib tug neeg nuclei lwj ntawm nws tus kheej los ntawm txhua lwm yam, nws yog xam hais tias qhov nruab nrab ntawm decayed tshaj ib lub sij hawm ntawm lub sij hawm xwm yeem mus rau lub sij hawm nondecomposed kaw txheej txheem. Yog hais tias koj ua raws li ib tug exponential kev cai lij choj, tus xov tooj ntawm tsis ntev los no decreases ho.

Cov kev siv ntawm lub phenomenon yog yus muaj los ntawm ob tug yuav tsum muaj thaj chaw ntawm lub teeb: Thaum lub sij hawm thiaj li hu ua ib nrab-lub neej thiab tej nuclei sredneraschitanny ncua ntawm lub neej. Thawj zaug nws txawv ntawm cov zauv feem ntawm ib tug thib ob nyob rau hauv lab thiab billions xyoo. Zaum ntseeg hais tias cov nuclei tsis loj hlob laus, thiab tsis muaj hnub nyoog lub tswv yim rau lawv.

Tej lwj txoj cai yog raws qhov thiaj li hu ua offset kev cai, thiab lawv, nyob rau hauv lem, yog ib tug rau txim ntawm lub hom phiaj ntawm lub preservation ntawm cov tub ntxhais xwb thiab loj tus xov tooj. Nws yog tsim los experimentally uas cov nyhuv uas cov magnetic teb ua nyob rau hauv ntau txoj kev: a) beam deflection tshwm sim raws li ib tug zoo them hais; b) raws li ib tug tsis zoo; c) tsis qhia tej yam tshuaj tiv thaiv. Los ntawm no nws hais ntxiv hais tias cov tawg yog ntawm peb hom.

Muaj cov tib tooj thiab hom ntawm cov hniav lwj txheej txheem: nrog qhov kev tso tawm ntawm ib tug electron; positron; haum ntawm ib tug electron thiab ib tug keeb. Nws yog muaj pov thawj hais tias cov keeb coj mus rau nws cov qauv ntawm cov hlau lead, muaj hniav lwj los ntawm emitting. Qhov kev tshawb xav lub npe hu ua alpha lwj thiab muaj lawm formulated G. A. Gamovym nyob rau hauv 1928. Qhov thib ob version twb formulated nyob rau hauv 1931 los ntawm Enrico Fermi. Nws tshawb pom tau hais tias cov hom ntawm electrons es tsis txhob nuclei emit opposite hais - positrons, thiab nws yog ib txwm nrog los ntawm cov emission ntawm ib tug particle nrog ib tug pes tsawg hluav taws xob xwb thiab so loj neurine. Qhov yooj yim piv txwv ntawm beta lwj yog ib tug proton ua haujlwm neuron nrog ib lub sij hawm lub sij hawm ntawm 12 feeb.

Cov theories, xav txog kev cai lij choj ntawm tej lwj, yog cov tseem ceeb kom txog rau thaum 1940 ntawm lub xyoo pua puv 19 mus txog rau thaum lub Soviet physicists G. N. Flerov thiab kos Petrzhak nrhiav tsis tau ib yam zoo, nyob rau hauv uas uranium nuclei nthawv muab faib ua ob sib npaug zos hais. Nyob rau hauv 1960 nws tau kwv yees muab ob npaug rau-proton radioactivity thiab-neutron. Tab sis mus txog rau tam sim no, qhov no hom ntawm lwj paub tseeb hais tias los ntawm xyaum ua tej yam tsis ua hauj lwm thiab tsis pom. Nws twb nrhiav tau xwb proton tawg, nyob rau hauv uas lub nucleus ntawm ib tug proton yog ntiab tawm.

Yuav kom nrog tag nrho cov teeb meem no yog ib qhov nyuaj, txawm hais tias tus kev cai lij choj ntawm tej lwj yog yooj yim. Nws tsis yog ib qho yooj yim to taub nws lub cev lub ntsiab lus thiab, ntawm chav kawm, qhov kev nthuav qhia ntawm no ziag no mus deb tshaj li qhov kev pab cuam ntawm physics raws li ib tug raug nyob rau hauv tsev kawm ntawv.