Implosion symmetry and burn efficiency in ICF

Abstract

The effect of long-wavelength irradiation nonuniformities on the performance of singleshell, reactor targets is investigated by means of 2-D numerical simulations. The stages of target collapse, hot-spot formation, ignition, and burn are illustrated. Evidence is shown for the occurrence of the Rayleigh–Taylor instability during target stagnation. It is then shown that the sensitivity of a given family of targets to the nonuniformities of the driving pressure critically depend on the 1–D ignition margin and on the spark convergence ratio of the target. The tolerable levels of nonuniformity as a function of the perturbation mode number are determined, for selected targets, by means of a parametric numerical study.