Dab tsi yog radionuclide? Tsis tas yuav ntshai lo lus no: nws tsuas yog txhais tau hais tias cov isotopes radioactive. Qee zaum hauv kev hais lus koj tuaj yeem hnov cov lus "radionucleide", lossis txawm tias tsawg dua cov ntawv sau - "radionucleotide". Lo lus raug yog radionuclide. Tab sis dab tsi yog radioactive decay? Dab tsi yog cov khoom ntawm ntau hom hluav taws xob thiab lawv txawv li cas? Hais txog txhua yam - in order.
Definition in radiology
Txij li thaum lub foob pob tawg thawj zaug, ntau lub tswv yim hauv hluav taws xob tau hloov pauv. Es tsis txhob lo lus "atomic boiler" nws yog kev cai hais tias "nuclear reactor". Hloov cov kab lus "radioactive rays" cov lus qhia "ionizing hluav taws xob" yog siv. Cov kab lus "radioactive isotope" tau hloov los ntawm "radionuclide".
Nyob ntev thiab luv-nyob radionuclides
Alpha, beta thiab gamma tawg nrog cov txheej txheem ntawm kev lwj ntawm lub atomic nucleus. Lub sijhawm yog dab tsiib nrab neej? Lub nuclei ntawm radionuclides tsis ruaj khov - qhov no yog qhov txawv ntawm lwm cov isotopes ruaj khov. Ntawm ib qho chaw, cov txheej txheem ntawm cov xov tooj cua tawg pib. Radionuclides ces hloov mus rau lwm cov isotopes, thaum lub sij hawm uas alpha, beta thiab gamma rays raug tso tawm. Radionuclides muaj ntau theem ntawm kev tsis ruaj khov - qee qhov ntawm lawv lwj dhau ntau pua, lab thiab txawm billions xyoo. Piv txwv li, txhua qhov tshwm sim ntawm uranium isotopes yog nyob ntev. Tseem muaj radionuclides uas lwj hauv vib nas this, hnub, hli. Lawv hu ua short lived.
Kev tso tawm ntawm alpha, beta thiab gamma hais tsis nrog rau kev lwj. Tab sis qhov tseeb, radioactive decay tsuas yog nrog los ntawm kev tso tawm ntawm alpha los yog beta hais. Qee zaum, cov txheej txheem no tshwm sim nrog gamma rays. Ntshiab gamma hluav taws xob tsis tshwm sim hauv qhov xwm txheej. Qhov siab dua qhov kev lwj ntawm radionuclide, qhov siab dua nws qib ntawm radioactivity. Qee tus ntseeg tias alpha, beta, gamma thiab delta decay muaj nyob rau hauv qhov. Qhov no tsis muaj tseeb. Delta lwj tsis muaj nyob.
Radioactivity units
Txawm li cas los xij, qhov ntsuas no ntsuas li cas? Kev ntsuas ntawm cov xov tooj cua tso cai rau tus nqi ntawm kev lwj mus rau hauv cov lej. Chav ntsuas ntawm kev ua haujlwm ntawm radionuclide yog becquerel. 1 becquerel (Bq) txhais tau hais tias 1 lwj tshwm sim hauv 1 sec. Ib zaug dhau los, cov kev ntsuas no tau siv ntau qhov loj ntawm kev ntsuas - curie (Ci): 1 curie=37 billion becquerels.
Tau kawgNws yog ib qho tsim nyog los sib piv cov tib pawg ntawm cov khoom, piv txwv li, 1 mg ntawm uranium thiab 1 mg ntawm thorium. Cov haujlwm ntawm ib chav tsev loj ntawm radionuclide hu ua cov haujlwm tshwj xeeb. Qhov ntev ntawm ib nrab-lub neej, qhov txo qis ntawm cov xov tooj cua tshwj xeeb.
Dab tsi radionuclides yog qhov txaus ntshai tshaj?
Nov yog ib lo lus nug uas provocative. Ntawm qhov tod tes, cov neeg nyob luv luv yog qhov txaus ntshai dua, vim tias lawv ua haujlwm ntau dua. Tab sis tom qab tag nrho, tom qab lawv lwj, qhov teeb meem ntawm hluav taws xob poob nws qhov cuam tshuam, thaum cov neeg nyob ntev ua rau muaj kev phom sij ntau xyoo.
Cov haujlwm tshwj xeeb ntawm radionuclides tuaj yeem muab piv rau riam phom. Yam riam phom twg yuav txaus ntshai: qhov uas tua tsib caug txhaj ib feeb, lossis ib qho uas tua ib nrab ib teev? Cov lus nug no tsis tuaj yeem teb - txhua yam nyob ntawm lub caliber ntawm riam phom, nws yog loaded nrog dab tsi, seb lub mos txwv yuav ncav cuag lub hom phiaj, qhov kev puas tsuaj yuav yog.
Qhov txawv ntawm hom hluav taws xob
Alpha, gamma thiab beta hom hluav taws xob tuaj yeem raug ntaus nqi rau "caliber" ntawm riam phom. Cov hluav taws xob no muaj ob qho tib si thiab qhov sib txawv. Cov cuab yeej tseem ceeb tshaj plaws yog tias txhua tus ntawm lawv tau raug cais raws li qhov txaus ntshai ionizing hluav taws xob. Qhov no txhais li cas? Lub zog ntawm ionizing hluav taws xob muaj zog heev. Thaum lawv ntaus lwm lub atom, lawv khob ib qho hluav taws xob tawm ntawm nws lub orbit. Thaum ib tug hais tawm, tus nqi ntawm lub nucleus hloov - qhov no tsim ib yam khoom tshiab.
Nature of alpha rays
Thiab qhov feem ntau ntawm lawv yog gamma, beta thiab alpha hluav taws xob muaj qhov zoo sib xws. los ntawm feem ntaualpha rays yog thawj zaug pom. Lawv tau tsim thaum lub sij hawm lwj ntawm cov hlau hnyav - uranium, thorium, radon. Twb tau tom qab kev tshawb pom ntawm alpha rays, lawv qhov xwm txheej tau qhia meej. Lawv tau dhau los ua helium nuclei ya ntawm qhov nrawm. Hauv lwm lo lus, cov no yog hnyav "poob" ntawm 2 protons thiab 2 neutrons uas muaj cov nqi zoo. Nyob rau hauv cov huab cua, alpha rays mus deb heev - tsis ntau tshaj li ob peb centimeters. Daim ntawv los yog, piv txwv li, lub epidermis nres tag nrho cov hluav taws xob no.
Beta hluav taws xob
Beta hais, tshawb pom tom ntej, tig los ua cov khoom siv hluav taws xob zoo tib yam, tab sis nrog ceev ceev. Lawv muaj tsawg dua alpha hais thiab kuj muaj hluav taws xob tsawg dua. Beta hais tau yooj yim nkag mus rau ntau yam ntaub ntawv. Nyob rau hauv huab cua, lawv npog qhov kev ncua deb mus txog ob peb meters. Cov ntaub ntawv hauv qab no tuaj yeem ncua sijhawm rau lawv: khaub ncaws, iav, daim hlau nyias.
Properties of gamma rays
hom hluav taws xob no yog tib yam li cov hluav taws xob ultraviolet, rays infrared lossis xov tooj cua tsis. Gamma rays yog photon radiation. Txawm li cas los xij, nrog kev kub ceev ntawm photons. Hom hluav taws xob no nkag mus rau cov ntaub ntawv sai heev. Txhawm rau ncua nws, feem ntau yog siv lead thiab pob zeb. Gamma rays tuaj yeem taug kev ntau txhiab mais.
Nkauj ntseeg kev txaus ntshai
Sib piv alpha, gamma thiab beta hluav taws xob, tib neeg feem ntau xav txog gamma rays yog qhov txaus ntshai tshaj plaws. Tom qab tag nrho, lawv tau tsim thaum lub sij hawm nuclear tawg, kov yeej ntau pua kilometers thiabua rau mob hluav taws xob. Tag nrho cov no muaj tseeb, tab sis nws tsis yog ncaj qha ntsig txog qhov txaus ntshai ntawm rays. Txij li thaum nyob rau hauv cov ntaub ntawv no lawv tab tom tham txog lawv lub peev xwm nkag mus. Tau kawg, alpha, beta, thiab gamma rays txawv ntawm qhov no. Txawm li cas los xij, qhov txaus ntshai yog ntsuas tsis yog los ntawm lub zog nkag mus, tab sis los ntawm cov tshuaj absorbed. Qhov ntsuas no suav nrog hauv joules ib kilogram (J / kg).
Yog li, koob tshuaj nqus hluav taws xob ntsuas yog ib feem. Nws tus lej suav tsis yog tus lej ntawm alpha, gamma thiab beta hais, tab sis lub zog. Piv txwv li, gamma hluav taws xob tuaj yeem nyuaj thiab muag. Cov tom kawg muaj tsawg zog. Txuas ntxiv qhov piv txwv nrog riam phom, peb tuaj yeem hais tias: tsis yog lub caliber ntawm cov mos txwv tseem ceeb, nws tseem ceeb heev uas qhov kev txhaj tshuaj raug rho tawm los ntawm - los ntawm rab phom los yog rab phom phom.
