Fabrication and Test of a Cryocooler Directly Cooled NbTi Superconducting Magnet

• Published in: IEEE transactions on applied superconductivity Vol. 20; no. 3; pp. 620 - 623
• Main Authors: Choi, Yeon Suk, Kim, Dong Lak, Yang, Hyung Suk, Kim, Jae Hwi
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-06-2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Boring; Conducting cooling; Conductors; Conductors (devices); Contact resistance; Copper; Crystal growth; current lead; Design engineering; Design. Technologies. Operation analysis. Testing; Electric connection. Cables. Wiring; Electrical engineering. Electrical power engineering; Electromagnets; Electronics; Exact sciences and technology; Fabrication; heat loads; Integrated circuits; Niobium base alloys; Niobium compounds; Refrigeration; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; superconducting magnet; Superconducting magnets; Superconductivity; Temperature; Testing; Titanium compounds; Various equipment and components; Asia; Korea; Thermal stress; Crystal growth; Performance evaluation; Multistage method; Cooling; Thermal management (packaging); Bias temperature instability; Magnet; heat loads; Contact resistance; High temperature; Superconducting magnet; current lead; Cooling system; Electrical conductor; Refrigeration; Conducting cooling; Multistage circuit; High temperature superconductor; Room temperature; Low temperature
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2010.2044034

The cryocooler directly cooled low temperature superconducting magnet is designed, fabricated and tested at the Korea Basic Science Institute (KBSI) for the crystal growth application. The magnet has one solenoidal configuration with a copper former which has a 52 mm room temperature bore. A two-stage 4 K GM cryocooler with 1.5 W refrigeration power is employed to cool the magnet from room temperature to liquid helium temperature. A pair of the binary current lead, a series combination of a normal conductor in the high temperature section and an HTS conductor in the low temperature section, is used for this application. The paper presents the process of design, fabrication and charging test. Also, the performance of the conduction cooled superconducting magnet system is discussed with respect to the supplied current and contact resistance.