Spectroscopic Study of Controlled Proton Impact on Molecular Nitrogen

Protons of energy 5-130 keV were passed into molecular nitrogen gas at low pressure and the resulting radiation spectroscopically analyzed. Prominent emissions studied were: (1) two ${\mathrm{N}}_{\mathrm{II}}$ lines located at $\lambda 5005$ Å and $\lambda 5680$ Å; (2) bands of the ${\mathrm{N}}_2^{+}$ first negative band system ($B{}_{}{}^2{}_{}{}^{}\Sigma -X{}_{}{}^2{}_{}{}^{}\Sigma$); and (3) two Balmer lines, $H_{\alpha }$ and $H_{\beta }$, formed by charge changing collisions with nitrogen molecules. Absolute cross sections for the production of these emissions were measured as a function of the energy of the incident protons. Population cross sections for the $v=0\mathrm{}$ and $v=1\mathrm{}$ levels of the $B{}_{}{}^2{}_{}{}^{}\Sigma$ state of ${\mathrm{N}}_2^{+}$ were obtained as well as an estimate of the level population cross section of the $n=3\mathrm{}$ and $n=4\mathrm{}$ levels of atomic hydrogen formed by charge exchange.