Lyman-αProduction and Polarization inHe+Collisions with H andH2

Abstract

The total cross section for Lyman-$\alpha$ production from ${\mathrm{He}}^{+}-\mathrm{H}\mathrm{}\left(1s\right)\mathrm{}$ collisions has been measured over the energy range from 0.5 to 30 keV. At the lower ion energies the cross section remains large. This probably reflects rotational interaction between certain states of the collision complex He${\mathrm{H}}^{+}$. A similar result had been reported by Stebbings et al. for the ${\mathrm{H}}^{+}-\mathrm{H}\mathrm{}\left(1s\right)\mathrm{}$ collision system. Also presented are measurements of the total cross section for Lyman-$\alpha$ production from ${\mathrm{He}}^{+}$-${\mathrm{H}}_2$ collisions. Some polarization values have been obtained for emission of Lyman-$\alpha$ from collisions of ${\mathrm{He}}^{+}$, ${\mathrm{Ne}}^{+}$, and ${\mathrm{Ar}}^{+}$ with atomic hydrogen.