Triply differential cross section and polarization correlations in electron bremsstrahlung emission

Abstract

We report results from a reformulation of the relativistic bremsstrahlung code of Tseng and Pratt. This permits calculation of the triply differential cross section ${\mathit{d}}^{3}$\ensuremath{\sigma} of bremsstrahlung (electron-photon coincidence measurements) in electron scattering on neutral atoms and ions. The cross section ${\mathit{d}}^{3}$\ensuremath{\sigma} is viewed as a more sensitive test of the theory, and predictions are needed for comparison with the more systematic and accurate experiments which are now being undertaken. The reformulation represents an extension of the previous code (which only calculated the doubly differential cross section), again utilizing partial-wave and multipole expansions in a screened potential within the independent particle approximation, but differently organizing their summation. The best previous predictions for the triply differential cross sections are due to Elwert and Haug, under assumptions less restrictive than Born approximation yet valid for high-Z elements only at very high incident electron energy. While we confirm differences from the Elwert-Haug results, we do not see a systematic improvement in the agreement with the limited previous experimental data, and further experiments are awaited with interest. \textcopyright{} 1996 The American Physical Society.