X-ray production by 1.5–11 MeV protons

Abstract

K-shell ionization and L x-ray production cross-sections by proton impact have been determined from measurements of K x-ray yields from thin targets of Ti, Fe, Co, Cu, Ni and Ag and of L x-ray yields from Au and Pb. The proton energies varied from 1.5 to 11 MeV. A Si(Li) semiconductor detector recorded the x-rays. The total error in the measured cross-sections is mostly less than 5 %. Kβ/Kα, ratios and Lι,β,ƴ/Lα, ratios have been determined. Ionization cross-sections have been compared with predictions of the plane-wave Born approximation (PWBA) and the binary-encounter approximation (BEA). Both theories describe the ionization quite well: PWBA is, however, better for higher proton energies whereas BEA is superior for lower energies. An empirical formula for ionization cross-sections is derived. (Less)