원문정보
초록
영어
Although high-temperature superconducting (HTS) magnets have the potential merit of producing ultra-high field (>25 T), they have been not easy to apply to Nuclear Magnetic Resonance (NMR) because of the difficulty of field homogeneity improvement. This paper presents a design technique of passive shimming for HTS magnets. Ferromagnetic shimming design code was developed though MALAB, which includes the optimization algorithm. The proper shim element size was determined by a simulation. This design technique was verified by a case study design of a 3-T HTS magnet. We succeed to improve field homogeneity of the magnet from 634 ppm to 6.39 ppm at 10-mm diameter sphere volume. Feasibility of passive shimming for all-HTS NMR magnet was confirmed by this result.
목차
1. INTRODUCTION
2. SHIMMING DESIGN
2.1. Field Mapping and Field Gradients
2.2. Theory of Ferromagnetic Shimming
2.3. Algorithm of Ferromagnetic Shim Design
2.4. Size Determination of Shim Piece
3. CASE STUDY ON SHIMMING DESIGN
4. CONCLUSION
APPENDIX
ACKNOWLEDGMENT
REFERENCES