Spectroscopic Study of Controlled Proton Impact on Molecular Nitrogen

Abstract

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 $\ensuremath{\lambda}5005$ \AA{} and $\ensuremath{\lambda}5680$ \AA{}; (2) bands of the ${\mathrm{N}}_{2}^{+}$ first negative band system ($B^{2}\ensuremath{\Sigma}\ensuremath{-}X^{2}\ensuremath{\Sigma}$); and (3) two Balmer lines, ${H}_{\ensuremath{\alpha}}$ and ${H}_{\ensuremath{\beta}}$, 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 $v=0$ and $v=1$ levels of the $B^{2}\ensuremath{\Sigma}$ state of ${\mathrm{N}}_{2}^{+}$ were obtained as well as an estimate of the level population cross section of the $n=3$ and $n=4$ levels of atomic hydrogen formed by charge exchange.