The energy distribution of the emission spectrum from pulsed surface discharges

This paper describes the results of an investigation into effect of the driving current pulse duration on the spectral distribution of radiated optical energy from a surface-discharge. The optical energy radiated from a pulsed surface discharge in an SF6/Ar gas mixture over a sapphire substrate was measured in six spectral bands; namely the 200-300 nm, 300-400 nm, 400-500 nm, 500-600 nm, 600-700 nm and that contained above the 700 nm wavelength. Three current levels were investigated and the pulse duration was varied in the range 250 ns-1100 ns in steps of 250 ns. The results have shown that the driving current magnitude and pulse duration affects significantly the distribution of the output optical energy within the spectral bands of interest. The results show that the efficiency of optical emission within the 200-300 nm spectral band increases from 25% to 37% as the driving pulse duration increases from 250 ns to 1100 ns. This is in contrast to the other spectral bands