L-shell ionization study of indium, tin, and rhenium by low-energy electron impact

The Lα, Lβ, and Lγ x-ray production cross sections of In, Sn, and Re by electron impact were measured at energies from near threshold to tens of keV. Thin targets with thick substrates were used in the experiments. We compare the experimental results of Sn x-ray production cross sections with data determined by Baxter and Spicer [Aust. J. Phys. 36, 287 (1983)] with a different method, and present some results. The measured x-ray production cross sections are also compared with the binary encounter approximation theory of Gryzinski [Phys. Rev. 138, A336 (1965)] and the atomic-rearrangement theory of McGuire [Phys. Rev. A 16, 73 (1977)]. It is found that the L-shell production cross sections do not exhibit a gradual increase with atomic number, a result observed by Park et al. [Phys. Rev. A 12, 1358 (1975)] in a systematic study of L-shell x-ray production cross sections by MeV electron impact. For the present measured L-shell data of In and Sn, it seems that, so far, none of the available theories can adequately interpret the L-shell results at low energies