Total bremsstrahlung spectra in targets of Al,Ti, Sn and Pb produced by complete absorption of 90Sr β particles

Total bremsstrahlung (BS) spectra in thick targets of Al, Ti, Sn and Pb produced by complete absorption of ⁹⁰Sr β particles (0–546 keV) are reported in the photon energy region of 10–30 keV. The experimental BS spectral photon distributions were compared with the theoretical BS spectral photon distributions obtained from Elwert corrected (non‐relativistic) Bethe–Heitler theory, modified Elwert factor (relativistic) Bethe–Heitler theories for ordinary bremsstrahlung (OB) and the modified Elwert factor (relativistic) Bethe–Heitler theory, which include the polarization bremsstrahlung (PB) into OB in stripped atom approximation. It has been observed that the experimental results are showing better agreement with the modified Elwert factor (relativistic) Bethe–Heitler theory having the contribution of PB at photon energy from 10 to 30 keV. This indicates the importance of PB in BS spectra, while studying the spectral photon distributions produced by continuous β particles having energy range of 0–546 keV in thick metallic targets. Further, it is observed that the contribution of PB into OB increases with increase in atomic number of the target and decreases with increase in photon energy. Copyright © 2010 John Wiley & Sons, Ltd.