Balmer-αand Balmer-βemission cross sections for H+Ar collisions

Absolute cross sections for the emission of Balmer-$\alpha$ and Balmer-$\beta$ radiations from H + Ar collisions between about 25- and 2500-eV hydrogen-atom energy and the polarization of the emitted radiations are reported. For hydrogen-atom energies above 250 eV, the contributions to these radiations from decay of the long-lived $3s$ and $4s$ excited states of hydrogen are resolved. The emission cross sections reach maximum values in the 100-eV hydrogen-atom energy range, where they are larger than the ionization cross sections for this reacting pair. The experimental techniques used to make the measurements are described and the results are compared with the work of other investigators. The available data are considered on the basis of a suggested model for the interaction.