Electron-impact excitation of some low-lying levels of neon

Abstract

First-order many-body theory has been used to calculate the differential and integral cross sections for electron-impact excitation of all the $3s$, ${3s}^{\ensuremath{'}}$ levels, and certain of the $3p$, ${3p}^{\ensuremath{'}}$ levels of neon, for incident electron energies ranging from 20 to 120 eV. The resulting differential cross sections for the excitation of the optically allowed $^{1}P_{1}$ and the $^{3}P_{1}$ levels show, for the 10\ifmmode^\circ\else\textdegree\fi{} \ensuremath{\le} \ensuremath{\theta} \ensuremath{\le} 80\ifmmode^\circ\else\textdegree\fi{} angular range, a discrepancy no greater than 15% when compared with recent experimental results, except for very few points. Spin-orbit coupling was included in the wave functions and its effect on determining the differential cross sections for the $^{3}P_{1}$ level was found to be very important for scattering angles less than 40\ifmmode^\circ\else\textdegree\fi{}. For the differential cross sections of the other $3s$, ${3s}^{\ensuremath{'}}$ levels the discrepancy in the 30\ifmmode^\circ\else\textdegree\fi{} \ensuremath{\le} \ensuremath{\theta} \ensuremath{\le} 80\ifmmode^\circ\else\textdegree\fi{} range is only slightly larger than the experimental errors. For the $3p$, ${3p}^{\ensuremath{'}}$ levels considered here, we have found strong disagreement with experimental data and there is also substantial disagreement among the various theoretical results.