Creation of the Indirect-Drive Cryogenic Target with the Solid Deuterium Layer

Abstract

An indirect-drive cryogenic target is necessary for research in the field of laser thermonuclear fusion at a megajoule energy level facility. Solid fuel layer in the target must meet high requirements: a roughness of the inner cryolayer surface must be less than 1 \(\mu\)m, deviations from the sphericity and the concentricity must be less than 1\(\%\). This paper describes the results of the research on meeting these requirements, notably, cryolayer formation and its characterization. Due to the slow crystallization method of the deuterium layer with its simultaneous heating by IR radiation, it is possible to obtain deviations from the sphericity and the concentricity of the inner cryolayer surface within limits of 2\(\%\), the roughness, within limits of 20 \(\mu\)m. Theoretical thermal calculations of the target construction are compared with experiment. The program system was developed using the optical shadow method which makes it possible to measure liquid fuel when filling the shell during the performance of the experiment, to perform the characterization of the solid cryogenic layer parameters, and to evaluate characterization results robustness.