High pressure electric discharge model applied to the halogen depletion instability development in a XeCl phototriggered laser

Abstract

Theoretical studies of a phototriggered XeCl excimer laser have been performed through the development of a zero-dimensional model and used for conditions close to experiment for about 50–100 ns laser pulse duration with electron power deposition in the MW/cm3 range and inside a 300 cm3 chamber. The well-known parallel resistor network model is used. The plasma generated by the impulse discharge is represented by one or more resistance in parallel, whose conductivity is proportional to the electron density. Time variation of the electron density is obtained by integrating the transport equations coupled to the heavy species kinetic and the external circuit. This study provides the time variation of the discharge characteristics as well as the influence of the gas composition on these characteristics. The results have been discussed and analyzed. Calculated discharge current and voltage are also compared with experimental results. Finally, the use of the present model allows a good comprehension of the halogen depletion phenomena, which is the principal cause of laser ending and allows a simple study of the evolution of a large-scale heterogeneity in preionization density and its effect on electrical and chemical plasma properties.