Scaled proton ionization cross sections in the Born approximation

Using the generalized oscillator strength formulation of the Bron approximation, proton ionization cross sections were calculated for a large sample of subshells of atoms throughout the periodic table. The results are presented in the form of scaled cross sections for all subshells up to the $6p$. Comparison with measurements shows reasonable agreement (better than a factor of 2), with some exceptions, for the proton energy range studied. The scaled cross sections presented herein are limited, in general, to proton energies greater than 184 times the subshell ionization energy.