Thick target bremsstrahlung spectra produced by 204Tl beta particles in the photon energy region of 10-30 keV

Total bremsstrahlung (BS) spectra in thick targets of Al, Ti, Sn and Pb targets produced by complete absorption of 204Tl beta particles are studied at photon energy from 10 keV to 30 keV. The experimental BS spectra measured with X-PIPS Si(Li) detector are compared with the theoretical BS spectra obtained from Elwert corrected (non-relativistic) Bethe-Heitler theory and modified Elwert factor (relativistic) Bethe-Heitler theories, with and without the contributions of polarization bremsstrahlung in a stripped atom approximation, described by Avdonina and Pratt (1999 J. Phys. B: At. Mol. Opt. Phys. 321 4261). It is observed that the experimental results show better agreement with the modified Elwert factor (relativistic) Bethe-Heitler theory having the contribution of polarization bremsstrahlung at photon energy from 10 keV to 30 keV. This indicates that the polarization bremsstrahlung must be taken into account while studying the spectral photon distributions produced by continuous beta particles in thick target materials.