Angular distribution of Lbeta x-rays from decay of L₃subshell vacancies in uranium and thorium following photoionization

Abstract

The anisotropy of L x-rays from the decay of L3 subshell vacancies in uranium and thorium following photoionization is investigated by measuring the angular distribution of photon induced L3 x-rays (Ll, L and L) in these elements. To enhance the chance of anisotropic emission of these x-rays, the measurements are made using selective photoionization of the L3 subshell in these elements. In contrast to the findings of earlier experiments in which L was observed to be isotropic, the present experiment gives clear-cut evidence of the anisotropic emission of this group and thus, strengthens the view of Flugge et al (1972 Phys. Rev. Lett. 29 7) that the vacancies after photoionization of states with J > ½ are aligned. The possible reasons explaining the observation of earlier workers that L emission is isotropic are also discussed.