Title :
Fabrication of NbTi Superconducting Joints for 400-MHz NMR Application
Author :
Junsheng Cheng ; Jianhua Liu ; Zhipeng Ni ; Chunyan Cui ; Shunzhong Chen ; Shousen Song ; Lankai Li ; Yinming Dai ; Qiuliang Wang
Author_Institution :
Key Lab. of Appl. Supercond., Inst. of Electr. Eng., Beijing, China
fDate :
4/1/2012 12:00:00 AM
Abstract :
NbTi superconducting joints (SJs) for a 400-MHz nuclear magnetic resonance (NMR) magnet system were fabricated using the superconducting solder matrix replacement in an open-air condition. A detection device for testing the resistance of SJ has been established. The results show that the overall resistance of SJs is 9.58 × 10-12 Ω under the background field of 1 T by summation of individual joint resistance. The resistance of SJs and the capability for current load should meet the demands of the NMR system. The SJs are placed inside the cylindrical vessel above the magnet. The magnetic flux inside the top of the vessel is no more than 0.3 T to assure performance of joints. As results, there is only 0.0001 ppm for homogeneity deviation caused by SJs on this NMR system, and therefore, the negative effect is negligible.
Keywords :
niobium alloys; nuclear magnetic resonance; solders; superconducting coils; superconducting magnets; superconducting materials; superconducting switches; titanium alloys; NMR magnet system; NbTi; cylindrical vessel; detection device; frequency 400 MHz; homogeneity deviation; magnetic flux; magnetic flux density 1 T; nuclear magnetic resonance; superconducting coils; superconducting joints; superconducting solder matrix replacement method; superconducting switch; Coils; Joints; Magnetic noise; Magnetic shielding; Nuclear magnetic resonance; Resistance; Superconducting magnets; Nuclear magnetic resonance (NMR) spectrometer; solder; superconducting joint (SJ); superconducting magnet;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2012.2185795
