Angular dependence of M and N band radiation and the effect of angular anisotropy on the total conversion efficiency of X rays emitted from a laser irradiated gold foil

Abstract

In this paper, we present the results of our theoretical studies on the angular dependence of M and N band peaks emitted from a laser irradiated gold foil. The M band peak is seen to be nearly isotropic, while the magnitude of the N band peak decreases as we move away from normal to the foil. The trend is similar to that reported in the experiments of Chase et al.: (1977) for aluminium foil. It is also observed that the N band peak shifts towards longer wavelength as the angle φ relative to the normal to the target increases. We also present the effect of angular anisotropy on time and frequency integrated total conversion efficiency of laser light into X rays using a high Z target. As compared with the diffusion approximation, a significant reduction in conversion efficiency is observed for a wide range of laser powers, and wavelengths.