Collisional Excitation of ${\mathrm{N}}^{+}$ at 50 keV

The excitation spectrum of ${\mathrm{N}}^{+}$ has been observed by examining the energy lost by a 50- keV ${\mathrm{N}}^{+}$ beam passing through a He target. The spectrum exhibits dramatic features with large cross sections. Determination of the approximate ratio of metastable to ground-state ions in the primary ion beam has permitted measurement of excitation cross sections from both ground-state and metastable ${\mathrm{N}}^{+}$ ions colliding with He target atoms.