Absolute electron impactK-ionization cross sections of titanium and nickel (≦50 keV)

The absoluteK-ionization cross sections of Ti and Ni by electron impact (impact energy ≦50 keV) was measured detecting the X-rays emitted by thin solid film targets of known mass thickness with a flow proportional counter. The experimental method, especially the correction procedures and the measurements are described, the results compared with calculations in different theoretical approaches. For impact energies aboveE ₀/E _K>1.5 (E _K=K-shell ionization energy) a systematic deviation of about +20% occurs in comparison with the best agreeing calculations of M.R.H. Rudge and S.B. Schwartz. A fit to Drawin's empirical formula reveals that the measurements are approximated better than ±10 % within the range of comparison.