Beta tawg

Lub nuclei ntawm tej yam atoms yog yus muaj los ntawm khov, uas yog manifested nyob rau hauv lawv muaj peev xwm mus hloov (txawj lwj), nrog los ntawm cov emission ntawm hluav taws xob (ionizing tawg). Feem ntau hom nuclear lwj yog lub beta tawg.

Tawg hu ua microparticles thiab ntau yam lub cev teb, uas muaj lub peev xwm mus ionize tshuaj. Nws tshwm sim kom txog thaum lub intrinsic haum ntawm tej tshuaj. Qhov chaw ntawm cov tawg (kev nuclear chaw los yog cia li tej tshuaj) muaj peev xwm, tsis zoo li cov tawg nyob rau ib lub sij hawm ntev heev. Ntuj tawg yog tam sim no nyob rau hauv peb lub neej li. Ionizing tawg muaj txawm ua ntej yug me nyuam ntawm lub ntiaj teb no tus thawj ntaub ntawv ntawm lub neej.

Beta tawg - nws yog ib tug kwj nruam ntawm positrons thiab electrons, uas yog tawm txim liab nyob rau hauv lub beta lwj ntawm tej atomic. Xws li ib tug lwj yam ntxwv tsis tag nrho cov atoms, tab sis tsuas yog tej yam tshuaj. Lub electrons (los yog positrons) yog tsim nyob rau hauv lub cores nyob rau hauv lub hloov dua siab tshiab ntawm neutrons rau protons los yog vice versa. Cov uas ua ruaj khov hais, uas tsis muaj kev them nyiaj thiab so loj, hu ua neutrinos thiab antineutrinos.

Thaum hluav taws xob lwj tsim tub ntxhais, nyob rau hauv lub xov tooj ntawm protons yog nce los ntawm ib tug, piv rau tus nqi ua ntej lwj. Nyob rau hauv positron lwj nuclear xwb ib chav tsev tsawg. Nyob rau hauv ob qho tib si zaum, qhov kev loj tus naj npawb tsis hloov.

Tawm txim liab electrons (los yog positrons) muaj ntau energies xws li los ntawm xoom lub siab tshaj plaws kev txwv ntawm lub zog Em (sib npaug zos rau ob peb MeV).

Beta tawg muaj ib tug tas mus li lub zog spectrum. Lub zog ntawm ntau ntau lub nucleus nrog discrete. Qhov no txhais tau tias nyob rau hauv txhua tom ntej lwj yuav tsum tau tso tawm tshiab zog. Tej saab laaj ntawm lub emission spectra vim lub fact tias cov hniav lwj los ntawm ib tug atomic tshaj zog yuav faib nruab nrab ntawm lub txim liab hais txawv. Yog li ntawd, lub spectrum neutrinos yog tawm txim liab thaum lub sij hawm lwj, nws yog tseem yus muaj los ntawm cov rooj saab laaj.

Ntsuas beta tawg spectrometers beta, beta tshwj xeeb txee thiab ionization lag

Tej isotopes uas lwj thaum nrog cov emission ntawm no hom, hu ua beta-emitters. Cov no muaj xws isotopes ntawm cov leej faj (S35), phosphorus (32P), poov hlau (Ca45) thiab lwm tus neeg. Yog hais tias cov hniav lwj yog tsis nrog gamma irradiation, nws yog hu ua ntshiab beta tawg.

Muaj ntau emitters (32P, 14C, Ca45, S35, etc.) Thiab siv nyob rau hauv diagnostic radioisotope thiab siv tau rau ib yam kev sim hom phiaj.

Dhau los ntawm lub substance, beta rays (beta tawg) ua num ua ke nrog lub nuclei ntawm nws atoms thiab electrons, siv rau nws tag nrho lawv lub zog thiab yuav luag tag siv ceev xwmphem nws txav. Txoj kev uas kis los ntawm tus beta-particle yeeb tshuaj, hu ua nqi kev mus. Nws yog qhia nyob rau hauv grams tauj ib square centimeter (denoted li g / cm2).

Beta tawg yog tau txeem mus rau hauv lub nyob lub cev nqaij mos rau ib tug tob ntawm 2 centimeters. Yuav kom tiv thaiv xws tawg yuav soj ntsuam Plexiglas tsim nyog thickness.

Beta-rays sawv cev rau ib yam ntawm cov hom ionizing tawg. Thaum dhau los ntawm lub rays poob zog tshuaj yuav ua tau rau ionization. Haum ntawm lub zog los ntawm qhov nruab nrab yuav ua rau ib tug xov tooj ntawm ob dab nyob rau hauv cov ntaub ntawv uas uas tau undergone irradiation. Piv txwv li, qhov no tej zaum yuav tshwm sim nyob rau hauv lub luminescence, tawg-tshuaj, hloov cov siv lead ua qauv ntawm tshuaj thiab thiaj li nyob. D. Cia li zoo li lwm yam ntawm hluav taws xob, beta rays muaj ib tug radiobiological los.

Kev siv cov beta tawg nyob rau hauv cov tshuaj raws li rau nws cov allergic nyob rau hauv lub thaj chaw ntawm cov ntaub. Rays siv ces, interstitial thiab intracavitary tawg txoj kev kho.