Design optimizations of IFMIF High Flux Test Module towards uniform specimen temperature distribution

The test specimen temperature control, together with optimized irradiation and reliability, is the central task of the HFTM design. The temperatures of the specimens should be kept at prescribed levels with acceptable temperature spreads. This paper concerns the design optimizations on HFTM through thermo-hydraulic simulations. Single-parametric studies were carried out for the effects of spacers, cooling channel/insulation gap deformation, multi-channels, insulation gap size, channel-rib contact resistance, etc. It is found that the temperature of the specimens and walls is generally sensitive to the above-mentioned parameters. These parameters therefore need to be considered during the optimization design, accounting also for the manufacture and operation tolerances. Simulation results on latest updated HFTM design are also presented. The results show that the current HFTM design could meet thermal management requirements in general. Further optimizations should be made individually for different target specimen temperatures.