Effect of molecular additions on the radiation parameters of a laser on Xe atomic transitions

An electron-beam-pumped laser on Xe atomic transitions is experimentally investigated at various pump durations and powers within wide ranges of pressures and working mixtures including additions of molecular gases. It is shown that the maximum specific lasing powers are achieved at high specific pump powers (above 200 kW cm^-3 atm^-1) and durations of the beam current pulse of tens of nanoseconds in high-pressure Ar – Xe mixtures with molecular gas additions (N₂ and CO₂). A specific output radiation power of ~ 4 kW cm^-3 is obtained. For a pump pulse durations from hundreds of nanoseconds to 1 μs, the highest lasing energies are reached without molecular additions at a comparatively low beam-current density (the specific pump power is ~ 10 kW cm^-3 atm^-1). However, in setups with specific pump powers above 40 kW cm^-3 atm^-1 and a working-mixture pressure limited by the strength of the laser chamber, molecular additions result in an increase in the radiation energy and efficiency. In wide-aperture facilities with high pump powers, molecular additions improve the distribution of the radiation power density over the laser-beam cross section.