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 measured 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 been corrected by a method based upon an electron transport calculation. For Sc and V elements, the experimental data are compared with some empirical formulae and theoretical results. It is found that the experimental data for Sc and V and most of the other elements measured before (i.e. Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb and Mo) with the same method as presented in this paper, can be reasonably described by both Luo's theoretical results and Casnati's empirical formula.