Argon excimer spectra excited in pulsed discharges with supersonic expansion

Emission spectra of the Ar/sub 2/ band at 128 nm, excited in a pulsed discharge with supersonic jet expansion, have been investigated under a range of gas pressures and voltages. Quartz, ceramic, and tungsten nozzles have been used. A significant observation is the narrow bandwidth of 9 nm at approximately 1 atm nozzle pressure, which decreases to 7.2 nm (FWHM) at 6.6 atm. Such a narrow bandwidth demonstrates that under the present experimental conditions, the observed band arises from the lowest vibrational levels of the excimer state.>