Low energy x-ray preionization source for discharge excited lasers

A low voltage (50 kV), low energy (3 J) x-ray preionization source has been developed specifically for avalanche discharge laser preionization. The new device uses a single stage high-voltage capacitor switched by a gradient grid hydrogen thyratron that drives a cold-cathode electron beam. Intense x-ray emission is produced by allowing the e beam to impact a high Z target foil. The entire system can operate up to 35 Hz repetition rate and produce an electron preionization density of ∼108 cm−3 in most rare-gas/halide laser gas mixtures.