Glauber Theory of Atomic-Hydrogen Excitation by Electron Impact

Abstract

The Glauber approximation has been applied to excitation of the $2s$, $2p$, $3s$, and $3p$ levels of the hydrogen atom by electron impact. The differential and integrated excitation cross sections predicted by the Glauber theory have been compared with experiment and with other calculations. The Glauber approximation is a considerable improvement over the Born approximation at energies \ensuremath{\sim} 100 eV. At energies > \ensuremath{\sim} 100 eV, the Glauber total excitation cross sections approach the Born approximation, even though at large scattering angles (>40\ifmmode^\circ\else\textdegree\fi{}) the Glauber differential cross sections may be very different from the Born approximation. At intermediate energies (\ensuremath{\sim}30-100 eV), the Glauber predictions are surprisingly good; at energies \ensuremath{\sim} 20 eV, the Glauber integrated cross sections are smaller than those observed experimentally.