Role of polarization Bremsstrahlung in theformation of thick target Bremsstrahlung spectra in the energy range of 5-10 keV

摘要

Role of polarization Bremsstrahlung in the formation of total Bremsstrahlung (BS) spectra in thick targets of Al, Ti, Sn and Pb, produced by complete absorption of~(90)Sr beta particles having an energy range of 0-546 keV, are studied in the photon energy region of 5 to 10 keV. The theoretical BS spectral photon distributions, obtained from Elwert corrected (nonrelativistic) Bethe–Heitler theory, a modified Elwert factor (relativistic) Bethe–Heitler theory that describe ordinary Bremsstrahlung (OB)and a modified Elwert factor (relativistic) Bethe–Heitler theory for BS spectra that includes the polarization Bremsstrahlung(PB) into OB in stripped atom approximation, were compared with the experimentally measured BS spectral photon distributions. It has been observed that the experimental results are in agreement with the modified Elwert factor (relativistic) Bethe–Heitler theory at photon energy from 5 to 10 keV. It has been also observed that the contribution of PB into OBdecreases with increase in end-point energy of beta emitter and the energy of the emitted photon. Further, it has been found that the contribution of PB into OB increases with increase in atomic number of the target atom. This indicates the importanceof PB in the formation of BS produced by continuous beta particle.