The model of turbulent mixing zone evolution, which accounts for the deviation from spherical symmetry of laser thermonuclear target compression

Abstract

The present report presents an analytical model destined to describe the development of hydrodynamic instabilities and their influence on the neutron yield under laser target compression. A number of specific numerical simulations formed the basis of the analysis. The plane and spherical tasks with certain initial conditions were considered. In a plane case the two pairs of gases typical for the shock tube experiments were studied. The spherical task was the modeling one and involved a small number of harmonics (the calculation parameters corresponded to the regime of laser compression). A notable difference in the calculation parameters of the gases in shock tubes and the laser compressed targets is not an obstacle for the construction of a unified model, since in gas dynamic problems the fundamental properties of gas-dynamic similarity are fulfilled.Basing on the simulations [1] and theory [2], the authors constructed a model of mixing zone development, which takes into account the initial conditions of perturbation. In addition to the earlier studied problems the report presents 2D-simulations of spherical target compression with account for the mixing processes. The simulations were aimed at determination of the degree of the mixing zone influence on the neutron yield.