Semi-Retractable Current Lead Cooled by a Cryocooler for High Field Magnet

• Published in: IEEE transactions on applied superconductivity Vol. 19; no. 3; pp. 2210 - 2213
• Main Authors: Choi, Y.S., Painter, T.A., Kim, D.L., Yang, H.S., Lee, B.S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Charging; Conducting materials; Conduction; Conduction cooling; Contact resistance; current leads; Disengaging; Electric connection. Cables. Wiring; Electric variables measurement; Electrical engineering. Electrical power engineering; Electrical resistance measurement; Electromagnets; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Feasibility; Helium; High field magnets; High temperature superconductors; Interfaces; Lead; Liquid helium; optimization; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Strips; Superconducting magnets; Superconductivity; Temperature measurement; Testing; Various equipment and components; Performance evaluation; Thermal management (packaging); Adaptability; Optimization method; current leads; Contact resistance; Conduction cooling; Optimization; High field; Electrical conductor; Resistor; Multistage circuit; High temperature superconductor; Multistage method; Cooling; Magnet; Electric contact; Superconducting magnet; Cooling system; Electric resistivity; Feasibility; Reliability; Strip material; Room temperature; superconducting magnets
• DOI: 10.1109/TASC.2009.2018044
• ISSN: 1051-8223

The semi-retractable current lead cooled by a cryocooler is designed for a high field superconducting magnet system. The semi-retractable current lead is composed of a normal metal element, conducting the current from room temperature to an intermediate temperature, and an HTS element, conducting the current down to liquid helium temperature. An HTS element and the joint between the normal metal and HTS element are connected to a two-stage cryocooler. The intermediate joint carries current through a strip of louvered material. After charging the normal metal element is disengaged from the HTS element without breaking vacuum in the insulating space. The semi-retractable current lead is fabricated and assembled with a two-stage cryocooler for feasibility test. The adaptability and reliability of the lead are tested during engage and disengage performance. The electrical contact resistance is also measured in the intermediate joint with respect to the vacuum level and temperature has been measured.