Current lead structure for superconducting electrical apparatus

摘要

An insulated pipe 6 has an open lower end extending into a cryostat 1 and a closed upper end in communication with the atmosphere through a vacuum chamber 3 surrounding the cryostat. A conductor 8a is disposed within the pipe and connected at its opposite ends between an external terminal 7a extending through the top of the pipe and an internal terminal 9 associated with an electrical apparatus mounted within the cryostat. An outlet 10 is provided in the top of the pipe to exhaust gaseous helium from the cryostat. The conductor is configured as a spiralling coil to minimize its axial length while maximizing its overall length to thereby enhance its cooling by the exhausting helium gas, and may be structurally supported by a core 12 disposed concentrically within the pipe.