HEAVY-ION BEAM PUMPED AMPLIFIED SPONTANEOUS EMISSION ON THE 172 NM XENON EXCIMER TRANSITION

Amplified spontaneous emission on the second xenon excimer continuum a t 172 nm wavelength was observed in dense gas evaporated from a solid xenon surface and pumped by heavy ions. A pulsed 3.78 MeV Kr+ beam fro m a radio-frequency quadrupole accelerator was used for the experiment . A series of 800 muJ particle pulses each 10 ns long was focused to a small, elliptical beam spot leading to a pump power density of the or der of 1 GW/g. Optical gain in the target was deduced from the angular distribution of light emitted along the target axis, and from a varia tion of optical intensity with gain length. A maximum gain of 26%/cm w as determined using a model calculation which reproduced the experimen tal data.