The LMJ: Overview of recent advancements and very first experiments

摘要

This paper describes the commissioning of the LMJ. The LMJ is a Nd-glass laser facility, located near Bordeaux (France), designed to focus up to 44 group of 4 beam lines (176 UV beam lines) on a micro-target located at the center of a 10 meters diameter spherical target chamber. These past years have been devoted to assembly and integrate the main structures in the target bay and in the 4 laser bays. The year 2014 saw the progressive commissioning of the equipment in order to realize the first experiments. The first part of the process involved the front-end commissioning, the measurement of the amplifying gain, the test of the wave front control system, the alignment of the laser beam from the front end to the final optics assembly, the tuning of the KDP crystals to optimize the frequency conversion efficiency. In the target bay, the main part of the work was to align the different equipment near the chamber center: the micro-target, the plasma diagnostic inserter and the plasma diagnostic itself and finally to measure the pointing performance on target. The communication between the equipment through the integrated control system and the adjustment of the integrated timing system in charge of the triggers signal for all the equipment were also a great challenge. This paper outlines these steps and illustrates the results obtained recently with the first bundle of the LMJ.