CharacteristicLX-Ray Spectra from Proton,α-Particle, and Oxygen Bombardment of Sn

Spectra have been measured [using a crystal (LiF;200) spectrometer] of $L$ x rays produced by 2.0-MeV proton, 3.2-MeV $\alpha$-particle, and 30.0-MeV oxygen bombardment of thick tin targets. $L$ x-ray lines are observed in the $\alpha$-particle-produced spectrum from initial configurations with up to four additional $M$-shell electron vacancies. The energy resolution of 8 eV (full width at half-maximum) did not allow any detailed structure to be resolved in the oxygen bombardment; an almost continuous structure is observed from multiply ionized tin. The ratios of x-ray yields from $L+M$ vacancies to yields from $L$ vacancies are shown to have the correct order of magnitude for a simultaneous direct Coulomb ionization process for proton and $\alpha$-particle impact.