ROLE OF PENNING IONIZATION OF THE MINOR SPECIES IN A NEON HOLLOW-CATHODE DISCHARGE

Using a tunable dye laser, a neon hollow cathode discharge was irradiated at wavelengths corresponding to lsn 2pnneon transitions, and thereby the neon metastablc atom population was perturbed. At these wavelengths, changes were detected in both the voltage across the discharge and in the ion signals for the various neon species, as well as for minor (including sputtered) species in the discharge. Attention is focused on the several possible ionization mechanisms for the minor species.Our results suggest that Penning ionization by metastablc neon atoms plays the most important role at low discharge currents, but only a minor role at high currents. © 1979, American Chemical Society. All rights reserved.