Lasing characteristics of the Ar — Xe and He — Ar — Xe mixtures pumped by fission fragments

The lasing characteristics of the Ar — Xe and He — Ar — Xe mixtures emitting at the transitions of the Xe atom at 1.73 and 2.026 mkm upon pumping by fission fragments in the BARS-6 pulsed reactor are studied. We describe an experimental setup and methods for measuring laser beam parameters and characteristics of the active medium of the nuclear-pumped laser in the free-running and master oscillator — amplifier regimes. The dependences of the laser pulse energy on the resonator parameters and the composition and pressure of the working mixture are studied in the free-running regime. A method of modulating the input signal of a single-pass amplifier is proposed for obtaining lasing characteristics of active mixtures. The lasing characteristics of the Ar — Xe and He — Ar — Xe mixtures (the unsaturated gain, saturation intensity, conversion efficiency, etc.) are determined from experiments in the amplifier — oscillator regime and compared with the results reported in other papers.