Radio-frequency preionization in a supersonic transverse electrical discharge laser

Preionization produced by a radio-frequency (RF) discharge near the cathode of a transverse flow electrical-discharge laser is used to initiate spatially diffuse discharge pulses in a Mach 3 flow of CO
2
-N
2
-He gas at pressures up to 160 torr. Main discharge uniformity and laser output performance have been determined as a function of pressure and RF discharge characteristics.