Numerical analysis for heat transfer from a Cd poison in cryogenic hydrogen

Tatsumoto, Hideki; Kato, Takashi; Aso, Tomokazu ; Hasegawa, Shoichi   ; Ushijima, Isamu*; Otsu, Kiichi*; Ikeda, Yujiro

In JSNS, Cadmium has been selected as a poison material in a hydrogen moderator to obtain narrow neutron pulse. The concern to adopt to Cd is how to bond Cd and Al alloy plate. R&Ds for bonding have been performed. But good bonding has not been obtained. Consequently, heat transfer between Cd poison and cryogenic hydrogen was studied for the case of insufficient bonding. The heat transfers for various bonding ratios were analyzed by CFD code (STAR-CD) without any turbulence model. The temperature rise in Cd poison for insufficient bonding was estimated. As a result, even the case of the bonding ratio of only 5 %, the maximum temperature of Cd is around 75K. Therefore, the expected heat transfer between the Cd poison and the hydrogen should be sufficient for insufficient bonding. Then, it is found that the any bonding method should be available for manufacturing method of Cd poison.