Abstract
This paper reports results, experimental and analytical, of the nonlinear behavior of a shim coil in the presence of an HTS coil assembled with double-pancake (DP) HTS-tape coils. The experimental results are from: 1) operation of a 700 MHz LTS/HTS NMR magnet (LH700) consisting of a 600 MHz LTS NMR magnet (L600) equipped with superconducting shim coils and a 100 MHz DP-assembled HTS insert (H100) and; 2) an experiment with a room-temperature (RT) Zl shim coil coupled to a 50 MHz DP-assembled HTS insert (H50). A field mapping theory with a harmonic analysis is applied to interpret both results. Based on experimental results and analyses, we conclude that the screening-current-induced field (SCF) generated by a DP-assembled HTS insert is primarily responsible for the nonlinear behavior, including strength degradation, of a shim coil.
| Original language | English |
|---|---|
| Article number | 5153105 |
| Pages (from-to) | 2285-2288 |
| Number of pages | 4 |
| Journal | IEEE Transactions on Applied Superconductivity |
| Volume | 19 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jun 2009 |
Funding
Manuscript received August 19, 2008. First published June 30, 2009; current version published July 15, 2009. This work was supported by the NIH National Center for Research Resources.
Keywords
- Double-pancake coils
- Field homogeneity
- HTS insert
- LTS/HTS NMR magnet
- Nonlinear behavior of a shim coil
- Screening-current-induced field