Balmer-αand Balmer-βemission cross sections for low-energy H collisions with He andH2

Abstract

Absolute cross sections for the emission of Balmer-$\alpha$ and Balmer-$\beta$ radiations resulting from H + He and H + ${\mathrm{H}}_2$ collisions are reported for hydrogen-atom energies between about 50 eV and 2.5 keV. The polarizations of the emitted radiations are also reported. For hydrogen-atom energies above 200 eV, the contributions to these radiations from decay of the relatively long-lived $3s$ and $4s$ excited states of the projectile atoms are resolved. The results of the measurements are compared with other available data for these reactions, as well as with data for H impact on other target species.