Field performance of an optimized stack of YBCO square "annuli" for a compact NMR magnet

Seungyong Hahn, John Voccio, Stéphane Bermond, Dong Keun Park, Juan Bascuñán, Seok Beom Kim, Tomita Masaru, Yukikazu Iwasa

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


The spatial field homogeneity and time stability of a trapped field generated by a stack of YBCO square plates with a center hole (square "annuli") was investigated. By optimizing stacking of magnetized square annuli, we aim to construct a compact NMR magnet. The stacked magnet consists of 750 thin YBCO plates, each 40-mm square and 80-μm thick with a 25-mm bore, and has a Ø10 mm room-temperature access for NMR measurement. To improve spatial field homogeneity of the 750-plate stack (YP750) a three-step optimization was performed: 1) statistical selection of best plates from supply plates; 2) field homogeneity measurement of multi-plate modules; and 3) optimal assembly of the modules to maximize field homogeneity. In this paper, we present analytical and experimental results of field homogeneity and temporal stability at 77 K, performed on YP750 and those of a hybrid stack, YPB750, in which two YBCO bulk annuli, each Ø46 mm and 16-mm thick with a 25-mm bore, are added to YP750, one at the top and the other at the bottom.

Original languageEnglish
Article number5710667
Pages (from-to)1632-1635
Number of pages4
JournalIEEE Transactions on Applied Superconductivity
Issue number3 PART 2
Publication statusPublished - Jun 2011


  • Compact NMR
  • Field cooling
  • Field homogeneity
  • Optimization
  • Temporal stability
  • Trapped field
  • YBCO plates

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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