Ztdependence of equilibrium charge state distributions of MeV He ions emerging from solid

Abstract

Listen

Translate article

The equilibrium charge state distributions of He ions emerging from various solid targets were measured in the energy range 0.6-2.4 MeV. Atomically clean target surfaces were prepared by continuous evaporation for Ga, Ge, Se and In, and by heating for Sc, Fe, Ta, W and Pt. The measured charge fractions Fi (i=0, 1, 2) were tabulated at 0.2 MeV intervals. In this energy range, the ratio F1/F2 is represented fairly well by the empirical formula AE-B, where E is the energy and A and B are target-dependent constants. The present data, together with the previous data, show clearly oscillatory behaviour of the equilibrium mean charge of He ions with target atomic number Zt. This oscillation is found to be attributed to the shell structure of the target atom.