L-shell x-ray production cross sections of Ni, Cu, Ge, As, Rb, Sr, Y, Zr, and Pd by (0.25–2.5)-MeV protons

L-shell x-ray production cross sections by ${}_1{}^1{}_{}{}^{}$${\mathrm{H}}^{+}$ ions are reported. The data are compared to the first Born approximation (plane-wave Born approximation for direct ionization and Oppenheimer-Brinkman-Kramers approximation for electron capture) and to the ECPSSR (energy-loss and Coulomb-deflection effects, perturbed stationary-state approximation with relativistic correction) theory. The energy of the protons ranged from 0.25 to 2.5 MeV in steps of 0.25 MeV. The targets used in these measurements were ${}_{28}{}^{}{}_{}{}^{}\mathrm{Ni}$, ${}_{29}{}^{}{}_{}{}^{}\mathrm{Cu}$, ${}_{32}{}^{}{}_{}{}^{}\mathrm{Ge}$, ${}_{33}{}^{}{}_{}{}^{}\mathrm{As}$, ${}_{37}{}^{}{}_{}{}^{}\mathrm{Rb}$, ${}_{38}{}^{}{}_{}{}^{}\mathrm{Sr}$, ${}_{39}{}^{}{}_{}{}^{}\mathrm{Y}$, ${}_{40}{}^{}{}_{}{}^{}\mathrm{Zr}$, and ${}_{46}{}^{}{}_{}{}^{}\mathrm{Pd}$. The first Born theory generally agrees with the data found in the literature at high energies and overpredicts them below 1.5 MeV. The ECPSSR predictions are in better agreement with experimental cross sections. At 0.25 MeV our data, however, are underestimated by this theory and tend to agree with the first Born approximation.