The ionization of inert gas atoms by electron and proton impact at high energies

At large impact energies E , the cross sections Q , for the electron or proton ionization of the inert gas atoms, are written in the form QE = A log E + B . A is calculated using theoretical and experimental values of the photoionization cross sections. The calculated A 's are in good agreement with the proton ionization of Hooper et al. but disagree with the electron ionization data of Schram et al. It is found that the electron ionization data of Golden and Rapp and of Smith are not sufficiently accurate to give reliable values for A . However, when the calculated values of A are normalized to these electron ionization data at impact energies between 20 and 30 atomic units we can obtain estimates for the B 's which are in good agreement with the proton ionization data. These B 's differ greatly from those of Schram et al.