X-ray production cross sections of thick Cu and Au targets induced by MeV Cq plus ions

This study measured K-, L-, and M-shell X-ray production cross sections (XPCSs) of thick Cu and Au targets induced by 1 MeV to 22 MeV multiple-charge-state C-ions as a function of ion energy and charge state, compared with using He-ions. XPCS measurements were based on the Merzbacher-Lewis relation. X-ray energy shifts and peak broadening were observed in materials irradiated by heavy C-ions, demonstrating that multiple ionization (MI) processes are at play for C-ions but not for He-ions. While the experimental XPCSs induced by He-ions aligned with predictions of theoretical models and did not exhibit charge state dependence, the XPCSs induced by C-ions exhibited more complex patterns, depending on ion energy and incident charge state. The complexity of the ion charge state effect was extended to the equilibrium charge state (ECS) in the thick target formalism. Theoretical models modified with MI and ECS exhibited improved predictions of the measured data.