Predictions for gain in the fission-fragment-excited atomic xenon laser

Abstract

The infrared atomic xenon laser (5d→6p) is an attractive candidate for fission fragment excitation, which provides low-power deposition (1–100 W cm−3), long pulse lengths (1–10 ms), and high-energy deposition (100s J ℓ −1). Optical gain at 1.73 and 2.03 μm has recently been measured in a reactor-excited xenon laser yielding values exceeding 0.03–0.05 cm−1 at power depositions of less than 10s W cm−3. Gain was also found to rapidly terminate before the peak of the pump pulse for some experimental conditions. A computer model has been developed to predict gain in fission-fragment-excited xenon lasers and these experiments have been analyzed. It is found that the termination of gain is most likely attributable to gas heating which increases the electron density, leading to electron collision quenching. The specific dependence of gain on pump rate suggests that a reduced rate of recombination of molecular ions with increasing gas temperature is partly responsible for this behavior.