Analysis of influence of spatial distribution error of directional infrared light on temperature field of cryogenic targets br

For an inertial-confinement-fusion cryogenic target, the fusion ice layer inside the capsule should have auniformity more than 99% and an inner surface roughness less than 1 mu m (root mean square) to avoid Rayleigh-Taylor instabilities. And this highly smooth ice layer required for ignition is generated in the presence ofvolumetric heat and affected by the thermal environment around the capsule. For the D2 fuel targets, theuniformity of the fusion ice layer inside the capsule is consistent with the uniformity of the surface temperaturearound the capsule, and the latter can be controlled by directional infrared illumination. A major challenge ofdirectional infrared illumination is the precision of directional infrared spatial distribution. In this paper, anumerical model coupling the directional infrared tracking and temperature field calculation is proposed andvalidated by experimental results. A three-dimensional physical model of the cryogenic target is used to studythe influences of different forms of directional infrared spatial distribution errors on the temperature uniformityof the capsule. The results show that the eccentricity of IR band axis has the worst effect on the temperatureuniformity of the capsule, followed by the distance between both IR bands, and the width of the IR band hasthe least effect on the temperature uniformity of the capsule. Therefore, the eccentricity of IR band axis shouldbe avoided in experiment to ensure the uniformity of the temperature of the capsule, further ensuring the uniformity of the fuel ice layer inside the capsule