<title>Modeling of a long-pulse high-efficiency XeCl laser with double discharge and fast magnetic switch</title>

Abstract

A complete model of a long-pulse x-ray preionized self-sustained discharge XeCl excimer laser has been established for the case of excitation by an advanced electrical circuit associating a double discharge (spiker/sustainer) and a fast low-loss ferrite magnetic switch with pulsed reset. This model allows simulation of the potential working conditions of the IMFM high average power, very high repetition rate LUX test-bed. The model, which considers Ne as buffer gas and HCl as halogen donor, includes a rate equation for species with the most recent available rate constant values, circuit equations with time-dependent ferrite inductance and plasma impedance and rate equation for laser emission taking into account absorbtions. Modeling takes into account time delay between spiker and sustainer, low value of sustainer field and dynamics of magnetic switch. The model has been validated with a long- pulse x-ray preionized XeCl laser, with double discharge and magnetic switching, developed at IMFM, which has already obtained over 3% efficiency and 140 mJ extracted energy in 150 ns (FWHM) from a 50 cm3 active volume at 2.5 atm. pressure. Numerical results are in good agreement (within 30%) with IMFM experimental results. A parametric study of the XeCl laser with double discharge and fast magnetic switch is presented as well as a comparison with both experiments and numerical results of excitation by a C-L-C classical circuit for the same geometric and gas conditions and the same input energy.