LMJ status: second bundle commissioning and assessment of first years of service

The Laser Megajoule facility, developed by the CEA is designed to provide the experimental capabilities to study high density plasma physics. The 176 Nd:glass laser beams of the facility will deliver a total energy of 1.4MJ of UV light at 0.35 μm and a maximum power of 400 TW. The laser beams are focused on a micro-target inside a 10-meter diameter spherical chamber. A first bundle of eight laser beams was officially commissioned in October 2014. Since then, several experimental campaigns have been carried out, to qualify LMJ experimental capability and to validate radiative hydrodynamics simulations. New target diagnostics were installed around the target chamber for that purpose. The installation of new bundles is continuing, simultaneously to the physics experiments. A second control room has been dedicated to the first steps of every bundle integration. In parallel with the assembly of the bundles, the laser process is continuously improving (low contrast beam profile, upgraded chamber center reference, improved focal spot profile). Second bundle commissioning has been achieved at the end of 2016 with some physics experiments using the 16 operational beams. The LMJ facility is now operational with two bundles (16 beams) and the bundle commissioning rhythm is increasing. The present performances meet the needed requirements for the physics experiments. We are currently integrating new bundles, increasing the LMJ laser beam energy, and installing new diagnostics in order to achieve the next configurations.