M-shell x-ray production cross sections for 0.5–2.5-MeV ${\mathrm{Be}}^{+}$ ions incident upon selected elements from praseodymium to bismuth

M-shell x-ray production cross sections are reported for ${}_4{}^9{}_{}{}^{}$${\mathrm{Be}}^{+}$ ions incident upon thin ${}_{59}{}^{}{}_{}{}^{}\mathrm{Pr}$, ${}_{60}{}^{}{}_{}{}^{}\mathrm{Nd}$, ${}_{63}{}^{}{}_{}{}^{}\mathrm{Eu}$, ${}_{66}{}^{}{}_{}{}^{}\mathrm{Dy}$, ${}_{67}{}^{}{}_{}{}^{}\mathrm{Ho}$, ${}_{72}{}^{}{}_{}{}^{}\mathrm{Hf}$, ${}_{74}{}^{}{}_{}{}^{}\mathrm{W}$, ${}_{79}{}^{}{}_{}{}^{}\mathrm{Au}$, ${}_{82}{}^{}{}_{}{}^{}\mathrm{Pb}$, and ${}_{83}{}^{}{}_{}{}^{}\mathrm{Bi}$ targets. Incident-beam energies range from 0.5 to 2.5 MeV (55.6–267 keV/u). The results are compared to the predictions of the first–Born-approximation theory and the perturbed-stationary-state theory with energy-loss, Coulomb-deflection, and relativistic corrections (ECPSSR). The first–Born-approximation theory overpredicts the measured cross sections everywhere, especially at high energies, while the ECPSSR theory tends to underpredict them, especially at low energy. This discrepancy between the measurements and the ECPSSR theory may be due in part to multiple-ionization effects which could change the fluorescence yields from the single-hole values used to convert total ionization to x-ray production cross sections in the theoretical calculations.