Modelling of the double pass X-ray laser effects on its focalisation

In this paper we describe a new ray trace code. This code is a three dimensional description of beam propagation, including half cavity mirror. It is based on the integration of the ray equation and on the calculation of the intensity along the plasma. It works as a post-processor of the hydrodynamic/atomic code « EHYBRID », which calculates the time evolution of the gain, the emissivity, the electronic density and the width of the plasma. We will present results obtained on different schemes of x-ray laser generation.