22-27 September 2019
Hyatt Regency Hotel Vancouver
Canada/Pacific timezone

Tue-Mo-Po2.07-01 [41]: Design of a Tabletop Liquid-Helium-Free, Persistent-Mode 1.5-T/90-mm MgB2 “Finger” MRI Magnet for Osteoporosis Screening

24 Sep 2019, 08:45
2h
Level 2 Posters 1

Level 2 Posters 1

Poster Presentation Tue-Mo-Po2.07 - MRI Magnets III

Speaker

Dongkeun Park (Francis Bitter Magnet Laboratory / Plasma Science and Fusion Center, Massachusetts Institute of Technology)

Description

We have finalized the design of a full-scale tabletop 1.5-T/90-mm MgB2 “finger” MRI magnet system for osteoporosis screening based on our preliminary test results of small coils and superconducting joints. The magnet will operate in persistent mode at 10 K with an additional 5 K temperature margin. The magnet design satisfies the required specification of a field homogeneity of <5 ppm over a 20-mm diameter of spherical volume (DSV) after cool-down and energization, and a fringe field of <5 gauss at 0.5 m in radius from the magnet center. A cryocooled solid nitrogen (SN2) cryogenic system minimizes the heat input especially when the cryocooler is switched off to provide a vibration-free measurement environment during the MRI scanning. This paper covers designs of: 1) the main coils and an iron shield; 2) coil former structures; 3) cryogenic system 4) protection circuit; and analyses of 1) quench; 2) heat input into the cold mass; and 3) manufacturing tolerance sensitivity on field errors. The magnet system, to be constructed and tested in 2019, will in 2020 be equipped with a set of active-shielded gradient coils, an RF coil, and a 1.5-T MRI imaging system.

Acknowledgement: Research reported in this publication was supported by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under award number R01EB022062.

Primary authors

Dongkeun Park (Francis Bitter Magnet Laboratory / Plasma Science and Fusion Center, Massachusetts Institute of Technology) Yoonhyuck Choi (Francis Bitter Magnet Laboratory / Plasma Science and Fusion Center, Massachusetts Institute of Technology) Yi Li (Francis Bitter Magnet Laboratory / Plasma Science and Fusion Center, Massachusetts Institute of Technology) Juan Bascuñàn (Francis Bitter Magnet Laboratory / Plasma Science and Fusion Center, Massachusetts Institute of Technology) Yukikazu Iwasa (Francis Bitter Magnet Laboratory / Plasma Science and Fusion Center, Massachusetts Institute of Technology) Hideki Tanaka (Hitachi, Ltd.)

Presentation Materials