Impact of 3D laser deviations on the Laser MegaJoule robustness
Abstract
In the Laser MégaJoule (LMJ) configuration, the robustness study must specify the sensitivity of the thermonuclear gain to laser and target deviations from their nominal characteristics. A MonteCarlo computation already provides the probability of failing to reach ignition from 2D standard deviations. This computation rests on an empirical model, deduced from SYMCAL simulations, which gives the radiation asymmetry on the DeuteriumTritium (DT) capsule. Then, a DT deformation model allows to compare these results to an ignition condition criteria. This method is here extended to 3D laser deviations. Basing the symmetry model extension on SYMCAL simulations with the 60 LMJ quads would lead to prohibitive calculation time and memory. We rather suggest to express analytically the radiation asymmetry due to quad power or pointing errors. Indeed, we use some properties of the spherical harmonic coefficients, which define this asymmetry, coupled to few onequad SYMCAL simulations. This study aims, in particular, to estimate the typically 3D effect of laser error contribution on the failure probability.
 Publication:

APS Division of Plasma Physics Meeting Abstracts
 Pub Date:
 October 2003
 Bibcode:
 2003APS..DPPFO2014F