Fuctional Structure ntawm Mammography Tshuab:
Bremsstrahlung (Bremsstrahlung), electron capture (Bremsstrahlung) thiab internal conversion (Bremsstrahlung) yog peb txoj kev los tsim X-rays. Bremsstrahlung yog lub tshuab uas lub tshuab X-ray tsim cov x-rays.
1.Electron capture: Beta decay muaj peb hom: beta - lwj, beta + lwj thiab electron capture (EC). Kev lwj ntawm electron capture (EC) tuaj yeem qhia tau tias niam txiv nucleus ntes ib qho exo-orbital electron, uas hloov cov proton mus rau hauv ib tug neutron thiab emits ib neutrino, yog li tus nqi ntawm tus me nyuam nucleus ua Z-1 thaum lub loj. tus naj npawb tseem tsis hloov. Feem ntau, cov khoom siv hluav taws xob hauv K plhaub feem ntau yuav raug ntes los ntawm lub hauv paus, vim tias lub plhaub K yog nyob ze tshaj plaws ntawm lub nucleus thiab muaj qhov ua tau zoo tshaj plaws ntawm kev ntes, tab sis qhov tshwm sim ntawm raug ntes hauv L plhaub kuj muaj. Tom qab lub nucleus ntes electrons, yuav muaj ib qho hluav taws xob nyob hauv K lossis L txheej ntawm tus ntxhais nucleus atom. Thaum ib qho hluav taws xob sab nraud sau rau qhov chaw tsis muaj, ib qho ntawm ob qhov xwm txheej hauv qab no yuav tshwm sim: Txawm tias lub zog ntau dhau raug tso tawm hauv daim ntawv kos npe X-ray, lossis lub zog dhau mus rau lwm cov hluav taws xob hauv lwm txheej, uas tau txais lub zog thiab tawm lub atom li Auger electron. Emission ntawm x-rays los yog Auger electrons yog lub cim ntawm K capture.
2. Kev hloov pauv sab hauv: Nuclei tuaj yeem ncav cuag lub xeev zoo siab los ntawm qee txoj kev (xws li beta lwj). Nuclei nyob rau hauv lub xeev zoo siab tuaj yeem hloov mus rau lub xeev qis dua lossis hauv av los ntawm emitting gamma rays. Qhov tshwm sim no hu ua gamma decay lossis gamma hloov. Tsis muaj qhov sib txawv tseem ceeb ntawm cov photon tawm los ntawm kev hloov pauv hauv nuclear thiab qhov hloov pauv ntawm atomic theem. Qhov sib txawv yog tias lub zog photon tawm los ntawm kev hloov pauv atomic tsuas yog eV ~ keV, thaum lub zog photon tawm los ntawm kev hloov pauv hauv nuclear yog MeV. Yog tsis xav txog qhov recoil ntawm lub nucleus, lub zog photon Eg tuaj yeem qhia tau tias Eg=es-ex. Qee lub sij hawm kev hloov pauv ntawm lub xeev zoo siab mus rau lub xeev qis zog tsis tso tawm photons, tab sis muab lub zog ncaj qha rau cov electrons sab nraum lub nucleus, ua rau lawv tawg tawm ntawm atom. Qhov tshwm sim no hu ua internal conversion (IC), thiab cov electrons uas tawg tawm ntawm lub atom hu ua internal conversion electrons. Lub nuclei hauv lub xeev zoo siab tuaj yeem rov qab mus rau hauv av los ntawm emitting γ photons los yog los ntawm kev tsim hluav taws xob hloov hluav taws xob sab hauv. Cov txheej txheem kiag li nyob ntawm lub zog theem ntawm cov nuclei. Qhov sib npaug ntawm lub zog kinetic ntawm lub zog hloov hluav taws xob sab hauv thiab lub zog ionization ntawm lub plhaub hluav taws xob yuav tsum yog lub zog sib txawv ntawm ob lub zog ntawm cov nucleus. Ntawd' yog sib npaug rau lub zog ntawm gamma photon emitted los ntawm kev hloov pauv ntawm ob qib atomic zog. Kev kawm txog kev hloov pauv sab hauv yog ib qho tseem ceeb txhais tau tias kom tau txais kev paub txog qib nuclear zog. Tau kawg, nws tuaj yeem tsim cov duab X-rays ntawm atoms los ntawm kev hloov pauv sab hauv.
