First-Cut Design of a Benchtop Cryogen-Free 23.5-T/25-mm Magnet for 1-GHz Microcoil NMR
Name
22ja039_full.pdf
Size
783.46 KB
Format
Adobe PDF
Checksum (MD5)
0bda30c54160fb6254ba5d50a02aafa9
Author(s)
Park, Dongkeun
Dong, Fangliang
Lee, Wooseung
Bascuñán, Juan
Iwasa, Yukikazu
Date Issued
August 2022
Journal
IEEE Transactions on Applied Superconductivity
Publisher
IEEE
Abstract
As a preliminary work, we have completed a 12.5-mm-cold-bore high-temperature superconducting (HTS) REBCO magnet prototype and successfully operated it up to 25 T at 10 K cooled by a cryocooler only, without liquid helium. In this paper we present the first-cut design of a cryogen-free all-REBCO 23.5-T/25-mm-warm-bore magnet having a high homogeneity of <0.1 ppm over a 1-cm diameter of spherical volume for a benchtop 1-GHz microcoil NMR spectroscopy. We also investigate a shielding design to reduce a 5-gauss fringe field radius to ≤1.5 m. This benchtop magnet will incorporate all the innovative design and operation concepts validated by the prototype magnet: 1) all-HTS composition and operation at above 4.2 K; 2) no-insulation winding technique with an extra shunting that makes this high-field REBCO magnet compact, mechanically robust, and self-protecting; 3) a single coil formation that leads, compared with the traditional multi- nested high-field NMR magnet, to simpler and more affordable manufacturing processes; 4) operational temperature-controlled screening-current reduction method which reduces peak stresses within the REBCO coil and field errors; and 5) cryogenic design for conduction-cooling operation.
Description
Submitted for publication in IEEE Transactions on Applied Superconductivity
MIT Department
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1109/tasc.2023.3252487
