Thermal and thermal-stress analyses of IFMIF liquid lithium target assembly

Abstract

For International Fusion Material Irradiation Facility (IFMIF) lithium (Li) target system, thermal shielding is important to keep temperature of the target assembly higher enough to avoid solidification of liquid Li. Required thickness of thermal shielding was clarified through thermal analysis of the target assembly. The thickness under vacuum condition could be reduced by using shielding material with low emissivity. Also it was found that the liquid Li should be charged under vacuum condition. Furthermore, thermal deformation is critical issue for maintaining stability of high-speed liquid Li flow along the concave backwall. Thermal-stress analysis of the backwall considering the nuclear heating was performed to evaluate the thermal deformation. The results showed that backwall deformation would be reduced by increasing heat transfer between the backwall and the target assembly.