Development and testing of a kinetics model for a nuclear-pumped laser medium

This work investigates the laser pumping processes in the Ne-N2 nuclear pumped laser. In this and several similar lasers, rare-gas metastables are formed in the radiation-induced plasma which transfer energy to a small quantity of molecular gas. Densities of the various species in the radiation-induced plasma and laser output power were modelled by numerical integration of the rate equations. The dominant gas-kinetic reactions were Penning ionization of N2 and N by the Ne metastables, followed in each case by recombination. The model predicts that increases in N2 pressure favor N production over N(+), leading to quenching of the laser; this has been confirmed by quantitative observations of laser output power. An experiment to measure N(+) densities directly in the radiation-induced plasma by photo-absorption in the vacuum UV is described.