Study of the build up of bremsstrahlung in metallic targets by beta particles of 204Tl and 32P

The buildup of external bremsstrahlung (EB) intensity as a function of target thickness in metallic targets of Al, Cu, Sn and Pb by beta particles of 204Tl and 32P beta emitters has been studied. Generation of EB intensity in successive layers of a thick target is described in terms of beta particle absorption while self-absorption of EB is evaluated by considering layer-to-layer transmission. The conventional beta stopper method is employed to measure the integral EB intensity in different target thicknesses. Comparison of calculated and experimentally measured EB growth curves shows a good agreement for various targets for both beta emitters. (author)