A cryogenic xenon droplet generator for use in a compact laser plasma x-ray source

A research instrument has been designed, fabricated, and tested that produces similar to 25-100 mu m diameter, liquid xenon droplets on demand at variable repetition rates of 1-100 Hz. Drops have been produced with low spatial dispersion which allows consistent interception by a high power laser beam to produce x-rays for advanced Lithography systems. Experimental sequences of up to 42, min in length have been conducted at 30 Hz, producing over 75 000 xenon drops. This technology allows significant debris reduction from the laser-target interaction. The mass-limited, cryogenic droplets are vaporized, producing no fragments, and the resulting gas can be collected preferentially on a cold surface for later recycling. (C) 1997 American Institute of Physics.