THE Laser MegaJoule FACILITY STATUS REPORT

THE Laser MegaJoule FACILITY STATUS REPORT H.Cortey, CEA/DAM CESTA, Le Barp, France Abstract The Laser MegaJoule (LMJ), the French 176-beam laser facility, is located at the CEA CESTA Laboratory near Bordeaux (France). It is designed to deliver about 1.4 MJ of energy on targets, for high energy density physics experiments, including fusion experiments. The first bundle of 8-beams was commissioned in October 2014 [1]. By the end of 2021, ten bundles of 8-beams are expected to be fully operational. In this paper, we will present: • The LMJ Bundles Status • The main evolutions of the LMJ facility since ICALEPS2019 • The result of a major milestone for the project: 'Fusion Milestone' INTRODUCTION The laser Megajoule (LMJ) facility, developed by the "Commissariat à l'Energie Atomique et aux Energies Alternatives" (CEA), is designed to provide the experimental capabilities to study High Energy Density Physics (HEDP). The LMJ is a keystone of the Simulation Program, which combines improvement of physics models, high performance numerical simulation, and experimental validation, in order to guarantee the safety and the reliability of French deterrent weapons. When completed, the LMJ will deliver a total energy of 1.4 MJ of 0.35 μm (3ω) light and a maximum power of 400 TW. The LMJ is sized to accommodate 176 beams grouped into 22 bundles of 8 beams. These will be located in the four laser bays arranged on both sides of the central target bay of 60 meter diameter and 40 meter height. The target chamber and the associated equipment are located in the center of the target bay. The first bundle of eight beams has been commissioned at the end of 2014. The second bundle has been commissioned at the end of 2016 following the same commissioning process. Seven additional bundles are now operational since the end of 2020, and the first physics experiments using the 56 operational beams took place in the second semester of 2019. The PETAL project consists in the addition of one short-pulse (0.5 to 10 ps) ultra-high-power (1 up to 7 PW), high-energy beam (1 up to 3.5 kJ) to the LMJ facility. PETAL offers a combination of a very high intensity petawatt beam, synchronized with the nanosecond beams of the LMJ [2]. The first phase of nuclear commissioning of LMJ has been achieved to take into account high-energy particles created by PETAL, and neutron production from D-D fusion reaction. A subsequent phase will take into account tritium targets. This paper describes the LMJ facility status and the new target diagnostics. A milestone physics experiments is presented to illustrate the facility capacity to realize the first thermonuclear fusion by implosion of a D2 capsule in a cavity.