Inelastic Scattering of Electrons and Protons by the Elements He to Na

Abstract

We have calculated discrete and continuum generalized oscillator strengths for all the occupied shells of He-Na and the $3s$ and $3p$ continuum generalized oscillator strengths for Ar. The calculations are done with a one-electron common-central-potential unrelaxed-core approximation. The generalized oscillator strengths were used to compute proton-excitation and -ionization cross sections and stopping power, electron-ionization cross sections, and neutral-neutral-ionization and -stripping cross sections. For proton ionization above 200 keV and electron ionization above 200 eV, the calculated cross sections are in better than 20% agreement with experiment. The calculated proton stopping power is lower than experiment by 25% at 100 keV and within 10% at 1 MeV. The computed He-He ionization cross section agrees with the measurement by Wittkower, Levy, and Gilbody, while the computed He-Ar ionization cross section is a factor of 5 higher than the measurement by Puckett, Taylor, and Martin.