Numerical analysis of the irradiation uniformity of a directly driven inertial confinement fusion capsule

The design of a directly driven capsule is carried out by 1D numerical simulation. Two configurations with 32 and 48 laser beams characterized by a super-Gaussian intensity profile have been considered and an ad-hoc 2D ray-tracing package has been developed to evaluate the uniformity of the time-integrated laser deposition energy. The time-evolution of the root-mean-square deviations of the deposited energy have been calculated. A robustness study as a function of the power imbalance has been performed showing that half of the shots performed with these two configurations provide the same irradiation uniformity. Laser beam parameters that keep the root-mean-square deviation lower than 1% are specified