Lyman-αRadiation Resulting From Ion Collisions with Molecular Gases

Cross sections for the emission of Lyman-$\alpha$ radiation resulting from ion—target-gas collisions have been measured for projectile energies between 1 and 25 keV. All combinations of ${\mathrm{H}}^{+}$, ${\mathrm{D}}^{+}$, $\mathrm{H}_2^{}{}_{}{}^{+}$, $\mathrm{D}_2^{}{}_{}{}^{+}$, and ${\mathrm{He}}^{+}$ projectiles on ${\mathrm{H}}_2$ and ${\mathrm{D}}_2$ targets as well as ${\mathrm{H}}^{+}$ and $\mathrm{H}_2^{}{}_{}{}^{+}$ on ${\mathrm{N}}_2$ have been studied. Although product excited H or D atoms which decay via the $2p-1s$ Lyman-$\alpha$-emitting transition may result from a variety of collision mechanisms, some interpretation has been possible using data from earlier experiments.