Argon excimer emission from pulsed discharge excited argon clusters formed in a planar expansion

Argon second continuum excimer emission is observed from a pulsed discharge excited pulsed supersonic planar argon expansion. The expansion nozzle consists of a 15 cm long slit with a variable width (75μm to 250μm). The pressure within the nozzle has been measured as varying between 2–4 bar. The excitation consists of a 100 ns negative pulse of 15kV and 1kA. The intensity of the argon excimer emission near 128 nm is investigated as a function of the width of the expansion nozzle slit, gas pressure, cathode-anode gap. The observation of the emission is conjectured to depend on the size and quantity of clusters formed in the expansion.