Thick targets of several heavy lanthanide (HoLu) compounds were bombarded by protons and 3He ions of 3 MeV/amu, and Mα and Mβ X-rays were measured with a crystal spectrometer. Ionization probabilities of the N-shell for zero impact parameter were obtained from the X-ray intensity ratio for proton and 3He ion impacts. A shell dependence of the ionization probability was found in a scaling plot. X-ray spectra of lanthanide compounds were compared and no chemical effect was observed. This result is considered to be due to the fact that the main component of Mα and Mβ lines is for radiative transition after the refilling of the 4f orbit (3d-14fn+1→4fn) where n denotes the number of 4f electrons of the target atom before ionization.
ASJC Scopus subject areas