L X-ray intensity ratios for proton impact on selected rare-earth elements

L X-rays excited by 75–300 keV protons impacting thick targets of Gd, Tb, Dy, Ho, Er, Tm and Yb were measured with a high-resolution Si(Li) detector equipped with an ultra-thin window. The intensities of the Lα(L3M4,5) and Lβ2,15(L3N4,5) X-rays relative to the Lℓ(L3M1) X-rays were compared with theoretical predictions. Discrepancies in the results are attributed to multiple vacancy production by various mechanisms. M4,5 and N4,5 ionization probabilities in these collisions are deduced from the results.