Indirect cooling experiment for magnetic alloy-loaded cavity

BackgroundIndirect cooling method is an alternative scheme for magnetic alloy (MA)-loaded cavity because of the feasible structure and MA core treatment process. Stable and long-term operation is not possible without a powerful cooling system for the high-power MA cavity.
PurposeThe paper reports a method to evaluate the cooling efficiency of an indirect cooling structure for high-power-loss MA cavity.
MethodsTwo types of helix metallic cooling plate were designed and checked by CFX code considering the average power loss more than 0.13 W/cc. In order to enhance the heat-transfer efficiency between the non-flatness surface of the MA core and metallic cooling plate, a filling material with high thermal conductivity is needed. Different commercial filling materials were investigated, and a high-power test bench was developed to assess the cooling efficiency. A parametric fitting method was adopted to qualify the heat-transfer coefficient according to the temperature rising curve.
ConclusionThe results indicate that the experimental data maintain good consistency with the CFX simulation results and the cooling structure meets the high-power-loss cooling requirement. The heat-transfer capability of the filling was influenced by the thickness of heat-transfer materials and the painting process. The heat-transfer performance of the thermal grease is better than that of the thermal gasket even though the latter has a higher thermal conductivity. The virtual thermal conductivity of the filling material was less than the product index and affirmed by the CFX transient simulation.