Analyses of molecular and neutral atomic emission spectra from an electrothermal launcher plasma

Abstract

Analyses of neutral atomic copper line and C/sub 2/ Swan Band (d/sup 3//spl Pi/-a/sup 3//spl Pi/) emission in the 420 to 570 nm spectral region from the experimental electrothermal launcher device SIRENS have been performed to determine edge and core plasma densities and temperatures. Time-averaged core arc temperatures of 10,000 to 22,000 /spl deg/K and arc densities of 7/spl times/10/sup 23/ to 2/spl times/10/sup 24/ m/sup -3/ have been deduced by measurements along the axis of the device using the relative intensities and the Stark broadening of the copper lines. The observed C/sub 2/ band spectra were compared with synthetic spectra calculated using a molecular spectra-radiative transport code. At a discharge energy of 1.56 kJ, for 90/spl deg/ aspect, the C/sub 2/ temperature was determined to be about 3500 /spl deg/K, with a column density of 2/spl times/10/sup 21/ m/sup -2/. On-axis spectra, at a discharge energy of 1.07 kJ, were found to correspond to a C/sub 2/ temperature of about 7500 /spl deg/K and a column density of 7/spl times/10/sup 20/ m/sup -2/. Because of the lower temperatures, it is believed that the C/sub 2/ emission comes from the plasma edge. >