Effect of Mixing at the Fuel–Ablator Interface on the Burning of Inertial Confinement Fusion Targets Upon Direct Irradiation with a Megajoule Laser Pulse

Abstract

We present the results of theoretical and numerical research on the burning of spherical thermonuclear targets under conditions where the peripheral part of the deuterium–tritium plasma is mixed with the surrounding inert substance of the target ablator; this takes place as a result of the development of hydrodynamic instabilities during the process of compression under the laser-pulse action. We investigate targets with parameters corresponding to the irradiation conditions given by the Russian Project on Megajoule Facility with an energy of about 2 MJ. For the investigated class of targets conforming to a large part of the evaporated ablator substance (no less than 75% of its initial mass), we show that the mixing does not spread to the region of strongly compressed fuel, which introduces a determining contribution to the propagation of the burning wave, not to speak of the central part of hot plasma responsible for the initiation of the burning wave. For this reason, the negative effect of the mixing on the burning efficiency of such targets is insignificant, and, as compared with the target burn in the absence of mixing, the released fusion energy decreased by no more than 20%.