Conceptual Design of Current Leads for a 21 T FT-ICR Magnet System

• Published in: IEEE transactions on applied superconductivity Vol. 17; no. 2; pp. 2228 - 2231
• Main Authors: Choi, Y.S., Painter, T.A., Kim, D.L., Lee, B.S., Yang, H.S., Miller, J.R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Conductors; Conductors (devices); Contact; Cryocooler; current leads; Cyclotron resonance; Cyclotrons; Design engineering; Disturbances; Electric connection. Cables. Wiring; Electrical engineering. Electrical power engineering; Electromagnets; Exact sciences and technology; Fourier transforms; heat loads; High temperature superconductors; Insulation; Liquid helium; Magnetic resonance; optimization; Superconducting magnets; Superconductivity; Thermal conductivity; Thermal loading; Various equipment and components; Fourier transformation; Magnet; Cyclotron resonance; heat loads; Optimization method; Cryocooler; current leads; high-temperature superconductors; High temperature; Thermal load; Optimization; Superconducting magnet; Electrical conductor; High temperature superconductor; Low temperature
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2007.898179

A new concept of current leads for a 21 T Fourier Transform Ion Cyclotron Resonance (FT-ICR) superconducting magnet system is presented. 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 employed. The HTS section is partly immersed in liquid helium and the joint between the normal metal and HTS conductor is cooled by the contact with a cryocooler. After excitation, the normal metal conductor section is thermally disengaged from the HTS section without disturbance to the insulating vacuum space and without requiring complete removal of the current leads. The present paper describes the so-called semi-retractable current leads for a 21 T FT-ICR magnet system application. The optimized dimensions of the leads are presented in order to minimize the thermal heat load when carrying operational current with some margin.