K-shell ionization of elements Ca to Zn for 0.5 to 2.5-MeV/amuN14-ion bombardment

Abstract

Target $K$-shell x-ray production cross sections, x-ray energy shifts, and $\frac{K\ensuremath{\beta}}{K\ensuremath{\alpha}}$ ratios have been measured for 7-35-MeV $^{14}\mathrm{N}$ ions on thin solid films of Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn. Comparisons of the data were made with theoretical predictions obtained from the binary-encounter approximation and the plane-wave born approximation (PWBA). These theories were found to overpredict the experimental data by a factor of 10 at the lower energies. However, at the lower energies, the PWBA, with modifications for increased target electron binding, Coulomb deflection, target electron polarization, and relativistic effects produced results in good agreement with the experimental data. At higher energies, a systematic deviation of the theoretical predictions from the experimental data was found which increases as the ratio of $\frac{{Z}_{1}}{{Z}_{2}}$ becomes larger. Corrections to the fluorescence yields attributable to multiple ionization processes and the addition of electron capture contributions to the previously indicated direct ionization theories produced results in excellent agreement with the experimental data with the exception of those for the light elements at the highest energies.