Temperature field and mechanical properties of cooling arm for cryogenic target

The cryogenic target is an important target type to achieve high inertial confinement fusion energy gain. The cooling arm connected the cool source to the aluminum sleeve is an important part of the cryogenic target, which is used to obtain accurate temperature field for the deuterium-tritium ice pellet, and uniformly clamp the aluminum sleeve. First the thermal conductivity of silicon material was measured，and the experiment shows that the silicon material has excellent thermal conductivity under the cryogenic temperature. Then the influences of structural parameters of the silicon cooling arm on the temperature field were analyzed. The impacts of different crystal orientation silicon cooling arm were studied, and the (111)silicon was chosen to fabricate cooling arm for its unique circumferentially uniform clamping force. The analyses of the clamping force, resonance frequency and the thermal-structure coupling analysis of the cooling arm were given. After that, the structure design of the cooling arm with two-level branch structure and 16 clamping fingers was proposed. Then the process of the cooling arm was designed based on MEMS technology and the prototype of cooling arm was realized. The vertical sidewall and mechanical properties of the cooling arm were measured. Finally the assembly sample of cooling arm with an aluminum sleeve was given, which indicated that the cooling arm can be achieved on clamping the sleeve.