Studies of total bremsstrahlung spectra from 89Sr beta particles in Mo and Pt metallic targets in photon energy region of 1-100 keV

Total bremsstrahlung spectra in thick targets of Mo and Pt, produced by beta emitter 89 Sr (end point energy = 1464 keV) have been studied in the photon energy range of 1-100 keV. The experimentally measured spectra measured were compared with the theoretical spectral distributions calculated from Elwert corrected (non relativistic) Bethe-Heitler [EBH] theory, modified Elwert factor (relativistic) Bethe-Heitler (F mod BH) theory for ordinary bremsstrahlung (OB) and the modified Elwert factor (relativistic) Bethe-Heitler (F mod BH+PB) theory, which includes the polarization bremsstrahlung (PB) into total bremsstrahlung (BS). The present results indicate the correctness of F mod BH+PB theory in the low energy region, where the contributions of PB into BS are dominant. But at the middle and higher energy region of the bremsstrahlung spectrum, where the contribution of PB is negligible, the F mod BH theory is more close to the experimental results.