Low Pressure Glow Discharge Switches For High Power Excimer Lasers

Pseudo-spark switches are promising condidates to overcome the limitations of pulsed power networks, imposed by the commercially available thyratrons in use. The pseudo-spark switch uses a high power density, low pressure glow discharge, and is capable of withstanding up to 100 % current reversal. Metal-ceramic prototypes have switched up to 40 kV/30 kA at a rate of current rise of 8 x 1011 A/sec. At 32 kV/20 kA and a pulse duration of 90 nsec (FWHM), repetition rates of over 100 pps and a lifetime of over 5 x 106 discharges have been achieved in a discharge circuit with a short circuit load. Streak camera measurements confirm that the discharge in the switch remains a homogeneous glow. The switches seem to be scalable to higher power levels; in addition, paralleling of separate discharge channels in a common housing has been shown to be possible.