Characterization of LIL laser UV focal spot

Abstract
One way to get the fusion of hydrogen in laboratory consists in heating and compressing a DT fuel capsule by using a laser. To reach this aim requires a new generation of high power laser facility. CEA is developing for this purpose a new 240 laser line facility, the LMJ facility. The LIL which is the prototype of four LMJ laser lines is operational now. In order to confirm the technical choices, a systematic characterization of LIL was carried out. A particular effort has been provided to measure the 3 high energy laser focal spot (1.5 kJ/700 ps and 5 ns for one beam) and the synchronization of laser beams onto the target, which are key issues for the plasma production. We present the experimental device designed to perform these measures: the SAT (a laser focal spot analysis system). That diagnostic which is located at the end of the laser lines supplied its first results during the 2004 quadruplet qualification campaigns. We will display and analyze caustic and focal spot results.