Downstream impact of flaws on the LIL/LMJ laser lines

In this paper we report several studies of the propagation of the Laser Integration Line (LIL) and Laser Megajoule (LMJ) beams when interactions occur with optical components defects. These studies are mainly achieved on a numerically predictive basis with the CEA MIRO beam propagation code. The flaws that we considered are located at the front or rear surface of the optical components. These surface flaws correspond to engineered defects such as scratches and to surface damage resulting from laser-induced growth process, from mitigation process or from target interactions debris. Results account for the possible downstream impacts of flaws at the rear-surface of the optics and from one component to another along the laser chain. In particular, the influence on the LIL/LMJ end-of-line focal spot intensity and size is predicted.