L3 subshell alignment in bismuth induced by swift silicon ions

Abstract

Angular- and impact energy- dependence of L x-rays of bismuth in collisions with silicon ions has been measured. Unlike isotropic emission of the -group and the -group x-rays, the Ll x-ray yield was observed to have impact energy dependent anisotropy emission. The anisotropy parameter for the Ll x-ray line was obtained by using the intensity ratio of the Ll-to-other L x-rays in the same spectrum. The alignment parameter of the L3 subshell was deduced from the measured anisotropy parameter of the Ll x-ray and has been compared with those obtained from the collisional theoretical models based on the plane-wave Born approximation and its extension.