K-shell X-ray cross sections of selected elements from Ti to Sb for incident protons and4He ions

The K-shell X-ray production cross sections and K beta /K alpha ratios have been measured for thin targets of Ti, Rb, Zr, Nb, Mo, Pd, Ag and Sb by protons and for thin targets of Ti, Cr, Co, Cu, Se, Rb, Zr, Nb, Mo, Pd, Ag and Sn by 4 He ions over the energy range of 1.5-3.8 MeV. The ionisation cross sections were calculated using atomic K-shell fluorescence yields and compared with the plane-wave Born approximation (PWBA) modified to included the effects of relativity, increasing target electron binding energy, target electron polarisation, Coulomb deflection of the incident particle and energy-loss effects in the ionisation process, resulting in the ECPSSR theory. The universal character of K-shell ionisation cross sections is discussed. The K beta /K alpha ratios are compared with theoretical predictions and with results reported by other authors.