<title>Theoretical and experimental investigations on pressure-wave reflections and attenuation in high-power excimer lasers</title>

Abstract

The first part of the paper represents theoretical investigations on the propagation and reflection of shock waves and the corresponding density perturbations which have been performed using a two-dimensional unsteady finite-difference method. The influence of electrode or mirror mounting design on the reflection of shock waves and the resulting density distribution is shown. It was found that in modifying the design, the local distribution of pressure and density in the laser gas can be influenced, but that the decay rate of the perturbations is not affected. The effect of using helium instead of neon as a major gas component is also briefly discussed. The second part describes the experimental setup to generate and investigate shock waves. In a special piston-driven shock channel of rectangular cross-section, remarkably good shock waves have been produced with regard to both the rise time and the evenness of the shock front. Interferometric observations of density variations (Delta) (rho) /(rho) as low as the order of 10-4 are possible. Some results of attenuating shock waves with a simple muffler design are presented.