M-shell x-ray production by 0.6–3.0-MeV ³He⁺ ions in tantalum, osmium, gold, bismuth, and thorium

M-shell x-ray production cross sections in ₇₃Ta, ₇₆Os, ₇₉Au, ₈₃Bi, and ₉₀Th bombarded by ³He⁺ ions of energy 0.6–3.0 MeV are reported. The data are compared with the predictions of the semiclassical and the first-order Born approximations and the calculations of the perturbed-stationary-state (PSS) theory that accounts for energy-loss (E), Coulomb deflection (C), and relativistic (R) effects (ECPSSR). The ECPSSR theory gives the best description of the measured cross sections, although a systematical underestimation of the data is observed in the low-velocity region. For tantalum, uncertainties of the available M-shell Coster-Kronig factors and fluorescence yields are indicated, as they have been noted previously for Z₂≊74 elements, bombarded by protons and ⁴He ions [Pajek et al., Phys. Rev. A 42, 261 (1990); 42, 5298 (1990)]. Using average M-shell fluorescence yields ω¯_M, we have obtained the scaled M-shell ionization cross sections, which were highly universal as a function of projectile velocity scaled to the mean M-shell orbital velocity. Finally, comparing our previously measured M x-ray production cross sections for ⁴He⁺ ions with the present data for ³He⁺ ions—taken at the same velocities—we try to test a description of the Coulomb deflection effect within the ECPSSR theory.