Spectra Excited in an Argon Afterglow

Abstract

The selective excitation of electronic spectra of gases by collisions of the second kind with energetic species in an argon afterglow has been investigated. A discharge was excited by a dc source in a high-velocity argon stream which was allowed to interact subsequently with 14 different gases in a reaction chamber several centimeters downstream. The nonluminous argon stream entering the reaction chamber through a nozzle formed cone-shaped diffusion flames in the chamber. Results of the spectroscopic investigation of the flames are presented together with the reaction mechanisms. The observed states of excitation as well as the conditions of the discharge indicate that the exciting species are the argon metastables 3P2 and 3P0.