DENSITY AND FIELD-INDUCED AUTOIONIZATION OF NO VALENCE STATES

The photoionization and absorption spectra of NO doped into argon for argon densities between the gas and the liquid are reported. As the ph otoionization threshold is lowered due to the increasing density, lowe r vibrational levels of the B' (2) Delta <-- X(2) Pi(nu',0) and G(2) S igma(-) <-- X(2) Pi(nu',0) valence transitions are forced to autoioniz e. An additional increase in the autoionization efficiency is observed when the ionization potential is further lowered by means of an elect ric field at a fixed density.