L-subshell ionisation cross sections of xenon by electron impact near threshold region

Abstract

L-subshell ionisation cross sections for xenon atoms have been measured by electron impact at incident electron energies from about one to three times the ionisation threshold energy of these subshells. Ionisation cross sections for the L1, L2 and L3 subshells were deduced from the measured yields of characteristic Lgamma 2,3,4,4', Lgamma 1 and Lalpha 1,2 X-rays, using known values for the fluorescence yields, transition probabilities and Coster-Kronig factors. The cross sections have been made absolute by normalisation on the simultaneously measured bremsstrahlung intensity, using the known bremsstrahlung cross sections data of Pratt et al. (1977). For the energies investigated, the subshell ionisation cross sections were always larger than the theoretical cross sections of McGuire (1978). However, only at the lower energies is this discrepancy larger than the experimental error bars (25-40%).