K-shell x-ray production cross sections are reported for ${}_4{}^9{}_{}{}^{}\mathrm{Be}_{}^{+}{}_{}{}^{}$ ions incident upon thin ${}_9{}^{}{}_{}{}^{}\mathrm{F}$, ${}_{11}{}^{}{}_{}{}^{}\mathrm{Na}$, ${}_{13}{}^{}{}_{}{}^{}\mathrm{Al}$, ${}_{14}{}^{}{}_{}{}^{}\mathrm{Si}$, ${}_{15}{}^{}{}_{}{}^{}\mathrm{P}$, ${}_{17}{}^{}{}_{}{}^{}\mathrm{Cl}$, and ${}_{19}{}^{}{}_{}{}^{}\mathrm{K}$ targets. Incident-beam energies range from 0.5 to 2.5 MeV. It is found that the first Born approximation (plane-wave Born approximation plus the Oppenheimer-Brinkman-Kramers treatment by Nikolaev) greatly overpredicts the data, while the predictions of the perturbed-stationary-state theory with energy-loss, Coulomb deflection, and relativistic corrections (ECPSSR) are generally in good agreement with the data. There is a low-velocity discrepancy between the data and the ECPSSR predictions which may be due to multiple ionization effects on the fluorescence yields used to convert total ionization to x-ray production cross sections.

• Received 10 March 1986

DOI:https://doi.org/10.1103/PhysRevA.34.2830