Effect of multi-variant on the thermal transfer of target system for the initiative isotopes accelerator

Abstract

Medical isotopes possess high value in disease diagnosis and therapy. The production of isotopes by spallation results in ultra-high target temperature which leads to impurity contamination to the isotopes. Improving the thermal contact resistances (TCRs) at the target-graphite case interface and the graphite case-heat sink interface is the effective way to control the target temperature. This work constructs experimental models for extreme condition application in terms of finite element simulations. A target system model was constructed according to the experimental setup, which includes graphite films, thorium targets, graphite cases and single target disk. Furthermore, a heat exchanger model was constructed to explore the role of thermal interfacial materials (TIMs) and microchannels. The simulation results of the target system model indicate that the desired temperature of the target can be accomplished when the target-case TCR is below 9 × 10−4 K m2 W−1 and the case-disk TCR is below 5 × 10−4 K m2 W−1, and the TCR between the case and the disk plays a more significant role in temperature reduction. The simulation results of heat transfer model explain that the difference in the thermophysical properties of the target and the case affect the beneficial effect of TIMs on the TCR. All of the above analyses provide theoretical guidance for the optimum design of the heat dissipation scheme for isotopes accelerator.