M-shell x-ray production cross sections from 75-300 keV proton impact on Hf, Re, and Au

M x-ray spectra from 75-300 keV proton bombardment of thick elemental targets of Hf, Re, and Au were measured using a ultra-thin window Si(Li) detector. Spectral analysis yielded x-ray production cross sections of the major x-ray transitions M$_{\alpha }$, M$_{\beta }$, M$_{\gamma }$, M$_{2}$N$_{4}$, M$_{1}$O$_{3}$ representative of vacancy filling of the five M sub-shells. Results are compared with predictions from non-relativistic ECPSSR and relativistic RPWBA-BC theories.