UHF Magnet Development at MIT

Transcription

1 UHF NMR/MRI Workshop Bethesda, MD November 12-13, 2015 Yukikazu Iwasa Francis Bitter Magnet Laboratory Plasma Science and Fusion Center Massachusetts Institute of Technology, Cambridge MA Acknowledgement NIGMS-NIBIB-(NCRR) and Juan Bascuñàn, Seungyong Hahn (FSU/NHMFL), Timing Qu, Mingzhi Guan Robert Griffin, Gerhard Wagner (HMS), Mei Hong 1/11

2 UHF NMR (54 mm)/mri (90 mm) Magnets B o 4.2 K Field Range < 20 > 20 è 100 Superconductor LTS LTS/HTS è HTS HTS (REBCO; Bi2223; Bi2212; here not MgB2) < 20 T (@4.2 K) magnets, HTS replacing Cost, not performance, primary criterion very challenging for HTS > 20 T (@4.2 K) magnets, HTS absolutely enabling Performance, not cost, primary criterion HTS essential 2

3 NMR Magnets: March Towards 1.3-GHz & Beyond B [T] LTS/HTS NMR Magnet Program [GHz] : Superconducting LTS [MHz] : COPPER [MHz] 1000 (Bruker) 1.02G (NIMS) 1.3G (MIT) 1.2G (Bruker) (MIT) (MIT) 0.7G (Phase 2) (MIT) 0.35G (Phase 1) (MIT) <iwasa@jokaku.mit.edu> Updated from Kobe Steel data (1998) Year

4 MIT 1.3-GHz NMR Magnet (1.3G) 1.3G Composed of: 500-MHz LTS NMR magnet (L500) 800-MHz REBCO insert (H800) Noteworthy features of 1.3G 1. H800: Non-Insulated (NI) REBCO pancake coils 2. Inside-notch double-pancake coils ì field homogeneity of short magnet 3. Persistent-mode HTS shims: Z1, Z2, X, (Y) 4. Bi2223 SCF shaking magnet 5. K LHe re-condensation Cryocooler (3.5 W@4.3 K) Recondenser ϕ54 RT bore Supports L500 H800 Bi2223 SCF Shaking Magnet HTS Shims: Z1, Z2 X,Y

5 3-nested-coil formation H800 (T op = 4.2 K; I op = 251 A) Each coil an assembly of NI pancake coils, wound with REBCO tape, 6-mm wide, 75-μm thick (10-μm thick copper, each side) overall Coil 1: 26 DP (6 inside-notch); 369 MHz (8.66 T); 90-mm bore Coil 2: 32 DP (8 inside-notch); 242 MHz (5.68 T) Coil 3: 36 DP (8 inside-notch); 189 MHz (4.44 T); 216 mm o.d. L500 cold bore: 237 mm H800 contribution: 61% of 30.5 T 5

6 Overband Overbanding an essential technique for highly stressed (i.e., UHF) coils 3-mm Coil 1: Hoop Stress vs. Radial Position 5-mm Winding Overband 7-mm Overband 7 mm 5 mm Mingzhi Guan, Seungyong Hahn, Juan Bascuñán, Timing Qu, Xingzhe Wang, Peifeng Gao, and Yukikazu Iwasa, A parametric study on overband radial build for a REBCO 800-MHz Insert of a 1.3-GHz LTS/HTS NMR magnet. presented at MT24. 6

7 Current Plans (9/1/15-8/31/18) Complete H800 Current Plans & Final Push Generate 30.5 T, of a non-nmr field quality Continue developing two new shimming techniques HTS shims Shaking-field Final Push (9/1/18-12/31/20) L500/H T Transform a 30.5-T magnet to a high-resolution 1.3-GHz NMR magnet (1.3G) Install 1.3G to the MIT-Harvard Magnetic Resonance Center, FBML 7

8 REBCO (MIT Choice) for H800 & UHF HTS NMR Magnets REBCO Tape vs. Bi2223 Tape & Bi2212 Multifilament wire Advantages Inherent strength: equally important as high critical-current density, J c REBCO > Bi2223 & Bi2212 Overall winding current density (J overall ): J overall è î magnet cost REBCO* >> Bi2223 & Bi2212 Magnet protection, from permanent damage REBCO* easier than Bi2223 & Bi2212 Disadvantage Inherent field impurity * Thanks to H800 NI coils * Thanks to H800 NI coils Purity: Bi2212* >> REBCO & Bi2223 * Thanks to multifilaments vs. New shimming techniques deployed to tape H800 pancake coils 8

9 UHF NMR Magnets Beyond 1.3 GHz >1.3G Magnets for NMR Solution NMR 15 N TROSY benefits from >1.3-GHz magnets* Magic-Angle-Spinning Solid State NMR Highest field possible** * Koh Taeuchi, Haribabu Arthanari, Ichio Shimada, and Gerhard Wagner, Nitrogen detected TROSY at high field yields high resolution and sensitivity for protein, in press JBNMR (2015). ** Lishan Yao, Alexander Grishaev, Gabriel Cornilescu, and Ad Bax, ``The impact of hydrogen bonding on amide 1 H chemical shift anisotropy studied by cross-correlated relaxation and liquid crysstal NMR spectroscopy, J. Am. Chem. Soc.~132, 10866(10pp) (2010) 9

10 NMR Magnets: March Beyond 1.3-GHz 1.3G (30.5T) 1.5G (35.2T) 2.0G (46.9T) 2.5G (58.6T_ (% by HTS) L500*/H800 (61) L500/H1000 (67) L500/H1500 (75) L500/H2000 (80) LTS Cold bore [mm] Mass [kg] ,450 18,630 I op [A] T op [K] 4.2 (* L500, all-nb3sn, up to 6) op [MJ] ($1M) 19 ($4M) 107 ($22M) HTS: REBCO 6-mm wide; Cold bore: 91 mm; I op = 300 A (except 1.3G: 251 A); T op = 4.2 K # Coils / Total DP 3 / 94 4 /140 6 / / 579 Conductor length [km] 12 (~$0.6M) 14 (~$0.7M) 38 (~$2M) 152 (~$6M) E op Overband / Coil [mm] 7 / 5 / 3 5 / 3 / 2 / 1 15/15/16/11/6/3.5 24/23/29/28/27/25/22/15 * L500 designs by Masatoshi Yoshikawa (JASTEC) 10

11 CONCLUSIONS MIT completing (2000) a 1.3G (500/800) high-resolution NMR magnet HTS share: 61% of 30.5 T For UHF NMR magnets, currently REBCO, among HTS, most suitable NI winding technique most viable More heavy lifting for HTS insert, perhaps 100% at 100 T (4.26 GHz) With HTS, the sky s the limit! 1.3G the only major UHF NMR program now funded in the U.S., i.e., by NIH NbTi mainly developed by large HEP projects è LHC Nb3Sn by large fusion projects è ITER For HTS, needed most now: more UHF NMR magnet building projects, supported not only by NIH but also by NSF and DOE Thank you! 11