Effect of fast electrons on the gain of a direct-drive laser fusion target
The results of numerical and theoretical studies of the gain of direct-drive inertial confinement fusion (ICF) target, which includes a kinetic description of energy transfer by laser-accelerated fast electrons, are presented. The range of initial temperature of fast electrons and fraction of laser energy contained in these particles were chosen based on the results of recent experiments at the National Ignition Facility (NIF).The effect of 'wandering' of fast electrons is taken into account. It is due to a remoteness of the region of fast electron generation from the ablation surface of imploded target. As a result a significant fraction of particles do not fall into the compressed part of target. The `wandering' effect leads to decreasing the negative effect of fast electron generation on the target's gain.