DESIGN AND PERFORMANCE OF LOW-THERMAL-RESISTANCE, HIGH-ELECTRICAL-ISOLATION HEAT INTERCEPT CONNECTIONS

Electrical conductors often require the removal of heat produced by no rmal operation. The heat can be removed by mechanical connection of th e conductor to a refrigeration source. Such connections require both e ffective heat removal (low thermal resistance) and effective electrica l isolation (high electrical resistance and high dielectric strength). Fabrication of these connections should be straightforward, and perfo rmance must be reliable and independent of operating temperature. The connection method described here involves clamping (by thermal interfe rence fit) an electrically insulating cylinder between an outer metall ic ring and an inner metallic disc. Material candidates for insulating cylinders include composites, e.g. epoxy/fibreglass, and ceramics, e. g. alumina. Design factors, including geometry, materials and thermal contact resistance are discussed. The design, construction experience and performance measurements of a heat intercept connection in a high- temperature superconducting lead assembly is presented.