A 170 J electron beam pumped XeF(C/spl rarr/A) laser

A pulse output energy of 170 J has been achieved from an XeF(C/spl rarr/A) laser system, pumped by a pair of counterpropagating, three-meter-long electron beams. This represents a record for all types of pumping, for this excimer system. Energy was extracted from a volume of /spl sim/100 L, using a free-running stable oscillator. No evidence of laser oscillations on the competing XeF(B/spl rarr/X) transition was observed. Within the extraction volume the laser gas was pumped at a rate of 140 kW/cm/sup 3/ (time average value), for a period of 1.7 /spl mu/s. The optical cavity was folded, giving a gain length of 6 m. The optical pulse duration was 0.8 /spl mu/s (full width at half maximum), and the observed flux buildup time of /spl sim/1 /spl mu/s was consistent with modeling and a measurement of the net gain. The specific output energy was 1.7 J/L which is comparable to that achieved in previous, small scale experiments at somewhat higher pump rate. The results confirm the volumetric scalability of the electron beam pumped XeF(C/spl rarr/A) laser system to high output energy per pulse, and the feasibility of operating this system at a low electron beam pump rate which relaxes constraints on the design of the electron gun and pulse power subsystems in a high output energy device. Means for extending the laser pulse duration and increasing the output energy of the specific test device are discussed. An output energy of /spl sim/1000 J is projected for an optimized gas cell width, for full size resonator mirrors, and with injection.<
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