Excitation of nitrogen by fast H3+ ions

The visible spectrum emitted from N2 under bombardment by 1-MeV H3+ ions has been studied with higher spectral resolution (linewidths down to 0.01 nm) than employed in comparable earlier work. The light yield versus gas pressure has been investigated in the 2--225-mTorr range (0.3--30 Pa) for a number of prominent spectral features attributed to atomic ions and to neutral and ionic molecules. The pressure functions are interpreted in terms of the constituents of the composite projectile. A considerable kinetic broadening observed for emission from N+, but not for other radiators, corroborates findings by Aarts and de Heer [Physica 52, 45 (1971), using electron impact] that this excited species results from the breakup of highly excited N2+ ions into electronically excited ionic fragments