Ionization cross sections of C₆₀by fast electron impact

Abstract

By means of a time-of-flight technique, we have measured cross sections for production of and ions from a gas-phase C60target bombarded by 0.4-5.0 keV electrons. The results were in fairly good agreement with other data at overlapping energies below 1 keV. Semiclassical calculations of the single-ionization cross sections were also performed up to 10 keV using the Deutsch-Märk formula proposed for the molecule. A fairly good agreement between the experimental and theoretical cross sections was obtained both in magnitude and in energy dependence. It was found that the double and triple ionization cross sections both decrease monotonically and exhibit no hump structure, indicating that the inner-shell ionization does not play an important role in electron-impact multiple ionization of C60 .