The cryogenic target thermal regulation is a core technique to achieve ignition in the Inertial Confinement Fusion. The temperature of DT layer in cryogenic target need to be lowered from DT triple point (19.79K) to ignition temperature (18.2K) in order to reduce the density of DT gas and increase the energy gain of cryogenic targets. Thermal model and disturbance analysis of LMJ’s cryogenic target have been studied. A control system based on synchronous detection and “multi-variable” algorithm has been proposed and simulations of both “Slowing Cooling” and “Quick Cooling” were carried out in Matlab/Simulink. The results show that both the dynamic and the static characteristics of the thermal control system can satisfy requirements of cryogenic target thermal regulation. Based on LMJ’s cryogenic target, thermal models for components of cryogenic target have been established and analyzed, including cryogenic arm (consisting of target base, gripper and heat exchanger) and the thermal model from target base to DT layer in the cryogenic target. Disturbance in the cryogenic target thermal regulation system has been studied in order to promote reliability of simulation results. This designed thermal control system performs multipoint synchronous temperature detection to improve measurement accuracy, and switches control schemes according to different cooling phases in order to meet specific requirements. Self-tuning fuzzy PID algorithm is chosen to design the controller, because this algorithm possesses good performance in both anti-interference ability (Fuzzy control’s advantage) and high resolution (PID algorithm’s advantage). Simulations of “Slow Cooling” and “Quick Cooling” have been performed in Matlab/Simulink to test thermal control performance. The quenching route optimization method for quick cooling phase in “Quick Cooling” has also been further studied in order to improve thermal control performance. The results show that the cryogenic thermal regulation system proposed here can satisfy thermal regulation requirements imposed by Inertial Confinement Fusion. Besides, the proposed quenching route optimization method can reduce time that DT layer needs to reach ignition temperature without increasing cooling speed of target base.
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