Development of \hbox\hbox Superconducting Coil Manufacture Technology

• Published in: IEEE transactions on applied superconductivity 2013-06, Vol.23 (3), p.4401204-4401204
• Main Authors: Junsheng Cheng, Yuanzhong Lei, Chunyan Cui, Lankai Li, Shousen Song, Yi Li, Zhipeng Ni, Shunzhong Chen, Hui Wang, Qiuliang Wang
• Format: Article
• Language: English
• Subjects: Epoxy impregnation; hbox{Nb}_{3}\hbox{Sn} coil; Heat treatment; Joints; Niobium-tin; Superconducting coils; superconducting joint; Superconducting magnets; Wires
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2012.2237009

The nuclear magnetic resonance superconducting magnet technology is being developed in our laboratory. Because the upper critical magnetic field of NbTi alloy is not high enough, an Nb 3 Sn superconductor has to be used in the manufacture of magnets for 500 MHz and above. In this paper, an experimental Nb 3 Sn superconducting coil was manufactured to study the fabrication technology. The bobbin with Al 2 O 3 ceramic coating is made of stainless steel. A vertical tube type vacuum heat treatment furnace was established for Nb 3 Sn formation. Heat treatment parameters for the Nb 3 Sn coil were done at 670 ° C in vacuum. Vacuum pressure impregnation was done to strengthen the assembly. The Nb 3 Sn coil, the switch, and the current leads were joined together using superconducting solder matrix replacement method. In the test the maximum current of the Nb 3 Sn coil was 263 A, corresponding to a central magnetic field of 3.47 T. Persistent current mode operation was also successfully performed.