PLASMA CATHODE PREIONIZED ATMOSPHERIC-PRESSURE HF CHEMICAL-LASER

The performance of an electric discharge, plasma-cathode-preionized, a tmospheric-pressure HF chemical laser was investigated and the laser w as geometrically optimized. The preionization electron density was mea sured at atmospheric pressure in helium and in a mixture of SF6 + H-2 diluted by helium. The measured preionization density is n(c) approxim ate to 6.7 x 10(9)-2 x 10(10) cm(-3), which is higher than the minimum critical density required for a self-sustained, homogeneous discharge of atmospheric-pressure electronegative gases. We have found improvem ent in laser specific energy for a diluted gas mixture of SF6 + H-2 du e to reduction in SF6 concentration. The effects of inter-electrode ga p height and plasma cathode grid width on laser performance were also investigated and are reported.