Emission Efficiency and Amplification Properties of the Plasma of a Pulsed Discharge in Ar at Elevated Pressures

Abstract

The spontaneous emission efficiency of an ${\rm Ar}_2^*$ excimer and its amplification properties at a wavelength of 126 nm are studied using a numerical model of the weakly ionized plasma of a pulsed discharge in Ar at elevated pressures. It is shown that, under real experimental conditions, it is possible to achieve a net gain coefficient of the active medium equal to ≈0.065 cm⁻¹ by increasing the gas density up to 4.0 × 10²⁰ cm⁻³ at an initial gas temperature of 170 K. The internal conversion efficiency of discharge energy into spontaneous emission depends weakly on the gas temperature and attains 75% for a gas density of 2.7 × 10²⁰ cm⁻³, but with excitation powers much lower than for the maximum gain. The applicability of the model at low excitation powers is tested by comparison with the experimental data.