2D low energy LMJ target design

Achieving ignition is one of the objective of the ``Laser MegaJoule'' (LMJ). Several indirect drive were designed to reach ignition with this laser. In an indirect drive configuration, laser light is converted to X-rays in a high-Z, typically gold, hohlraum. The resulting radiative energy drives the implosion of the central cryogenic DT capsule. Inside the hohlraum, a low density gas, for example H-He mix, retains the gold blowoff. The LMJ will deliver up to 2 MJ and 550 TW. A 1.4 MJ ignition target has already been designed. We present here the 2D design of a smaller target which requires 1 MJ and 300 TW of laser energy and power. This target could be shot during pre-ignition campaigns. Then, we compare both targets. In the smaller one, optimizing the beam passage through the laser entrance holes and tuning the radiation symmetry have become a real issue. Especially, we study the influence on radiation symmetry of H-He gas density.