Measurement of scandium and vanadium K-shell ionization cross sections by electron impact

Electron impact Sc and V K-shell ionization cross sections have been measur ed for the first time in the incident energy region from near threshold to 45 keV. Thin targets with thick substrates are used in the experiments. The influence of the substrate on measured data has bean corrected by a method based upon an electron transport calculation. For Sc and V elements, the e xperimental data are compared with some empirical formulae and theoretical results. It is found that the experimental data for Sc and V and most of th e other elements measured before (i.e. Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb a nd Mo) with the same method as presented in this paper, can be reasonably d escribed by both Luo's theoretical results and Casnati's empirical formula.