Computational study of X-ray radiation effects on hydrodynamic instability

The initial imprint of density perturbation due to spatial nonuniformity of laser intensity is one of the most important issues in laser fusion research. Several imprint mitigation scheme by means of soft x-ray radiation have been proposed to reduce the induced perturbation through the thermal conduction region. One of the schemes uses an external x-ray source prior to laser incidence to produce preformed plasma. Another has a low-density foam layer and high-Z material to heat the foam radiatively and make it uniform. We present the dynamics of these schemes and the perturbation growth with nonuniform laser from the results of two-dimensional simulation using our integrated code.