Abstract

Time-resolved spectroscopy has been undertaken on the emission spectrum of molecular nitrogen excited in pulsed discharges in a wide variety of conditions. Among the parameters which have been varied are voltage, current, pressure, gas mixture, tube dimension, pulse frequency, and pulse width. Recent interest has centered on the latter two variables with the finding that increased pulse frequency can be correlated with a rise in the apparent vibrational temperature of the ground state of nitrogen. This Is deduced from the measurement of the pattern of relative band intensities in the first positive system (1PG) through the visible and the infrared. Another finding is that there is a continual rise in the emission intensity from low- lying levels of the 1PG as the exciting pulse width is increased up to some 150 µs, after which the intensity (and thus the population of the level) reaches its saturation value. The excitation curves are currently being studied as a source of excitation process information by means of techniques previously applied to decay curves.

© 1986 Optical Society of America