Present Status of Pumping Methods of Lasers Using Nuclear Reactions

A review is presented, which summarizes both experimental and theoretical studies reported during the nine-year period 1964-73 on pumping methods for lasers using nuclear reactions either with or without electrical discharge (Nuclear Pumped Lasers or else Direct Nuclear Pumped Lasers). In much of the reported experimental work, the 10B(n, α)7Li and 3He (n, p)3H nuclear reactions have been utilized as source for high energy heavy particles with neutron fluxes ranging from 108 to 1017n/cmcm2·sec. Most of the theoretical work has been focused on the calculation of threshold neutron flux requirements for noble gases or CO2 lasers. The threshold estimates fall in the range 1.2×109-1018n/cmcm2·sec on 10B. A theoretical model was proposed by Guyot et al. which predicts the behavior of the metastable densities in noble-gas plasmas created by nuclear radiations. The present author is now undertaking jointly with Shipman a study of the electron energy distribution function in nuclear pumped lasers using the combined Boltzmann-Fokker-Planck equation.