Born-Wave Calculation of Atom-Atom Inelastic Cross Sections: Excitation ofHe(1S1)toHe(NL1)by Hydrogen Atoms

Total first Born-wave excitation cross sections are calculated for $\mathrm{He}\left(1\mathrm{}{}_{}{}^1{}_{}{}^{}S\right)+\mathrm{H}\mathrm{}\left(1s\right)\mathrm{}\to \mathrm{He}(2\mathrm{}{}_{}{}^1{}_{}{}^{}S, 3{}_{}{}^1{}_{}{}^{}S, 4{}_{}{}^1{}_{}{}^{}S, 5{}_{}{}^1{}_{}{}^{}S, 2{}_{}{}^1{}_{}{}^{}P, 3{}_{}{}^1{}_{}{}^{}P, 4{}_{}{}^1{}_{}{}^{}P, 3{}_{}{}^1{}_{}{}^{}D, 4{}_{}{}^1{}_{}{}^{}D, 5{}_{}{}^1{}_{}{}^{}D)+\mathrm{H}\left(\Sigma \right)$ over the energy range 1.0 keV to 1.6 MeV. The highly accurate numerical generalized oscillator strengths of Kim and Inokuti and of Bell, Kennedy, and Kingston are used to describe the projectile excitations. The complete summation over target final states if performed both exactly by use of the analytic generalized oscillator strengths and approximately by use of the closure relationship. The results are compared with available experimental data and previous calculations, and the discrepancies are discussed. The differences between results calculated by summation over all the target final states and those calculated by the assumption of closure are also discussed.