Overview of LMJ alignment to target chamber center and very first results

The laser Megajoule (LMJ) is a high energy laser facility (176 UV beam lines) designed for High Energy Density Physics. The end of the year 2014 was devoted to the progressive commissioning of the LMJ to achieve the first experimental campaign with 8 beams. This paper describes the alignment system developed in order to focus the laser beams and point the plasma diagnostics on the target. Alignment performances have been validated at very low power (1J front end shots) on an active target supporting a CCD sensor. Additional high power pointing shots have been performed to complete the characterization. We have demonstrated beam to target positioning accuracy < 52μm rms which is the LMJ requirement.