Balmer Emissions Induced byH2+andH3+Impact on Molecular Hydrogen

Absolute cross sections for the production of ${\mathrm{H}}_{\alpha }$, ${\mathrm{H}}_{\beta }$, and ${\mathrm{H}}_{\gamma }$ emissions by ${\mathrm{H}}_2^{+}$ and ${\mathrm{H}}_3^{+}$ impact on molecular hydrogen have been measured for ion energies up to 130 keV. Emissions resulting from dissociative electron capture by the fast ion or from dissociative excitation of the fast ion are Doppler shifted from emissions resulting from dissociative excitation of the target gas, allowing separate measurements of these emissions.