Krypton-fluorine lasers

Los Alamos Laboratory in New Mexico has terminated its work with the ANT ARES system operating at 10.6 micrometers because it was shown it would not be possible to generate sufficient heating or compression with the 10.6 micrometer wave length radiation. They have turned their efforts to the development of krypton-fluorine lasers. They have generated 10,000 joules pulses at 250 nanometers at efficiency of 1.5%. In 1989, this laser system had not yet been incorporated into a fusion test apparatus and little recent data is available. 

Figure 2 shows a schematic of the system that was used to flood expose the resist films. A Quanta Ray EXC-1 KrF excimer laser was used for all exposures. The laser output at 30 keV was 30-55 mJ/pulse/cm with a 0.33% fluorine, 5% krypton, and 94.67% neon gas mixture at 45 psig. The beam, at 100 pulses/sec., was reduced to a 3 mm diameter spot using aperatures. A 5 mm diameter light pipe was used to scramble the beam and improve uniformity. 

Lxciiner lasers contain a gaseous mixture of helium, fluorine, and one of the rare gases argon, krypton, or xenon. The rare gas Is clecironically exciled by a current followed by reaction with fluorine to form excited species such as Arl. KrI, or which arc... 

The active medium of the KrF laser is a mixture of krypton, molecular fluorine F2, and helium or argon as buffer gas. The whole gas system can be operated in a closed cycle where the gas is pumped from a reservoir through the laser channel. In the fast discharge, excited Kr and Ar atoms and ions are formed by electron impact. The excimers are formed by several reactions, for example. 

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