A planar jet expansion discharge source of molecular afterglow emission

A pulsed discharge source, operating in a free jet-expanded molecular beam, has been constructed. Variable ballast resistance provides control over two modes of operation characterized by distinct electron temperatures for several different molecular species. The low temperature mode is accompanied by intense afterglow emissions from metastable states and high ion production. Relative yields of atomic and molecular ions in a nitrogen discharge are used to determine the discharge electron energy and density. Afterglow emission from C 3Πu→B 3Πg transitions is attributed to radiative cascade from the E 3Σg+ state. Observed vibrational intensities are used to determine the relative vibrational population of the E 3Σg+(v=0,1) levels produced in the discharge.