Watch-sized 12 Tesla all-high-temperature-superconducting magnet

Pin-Hui Chen; Chukun Gao; Nicholas Alaniva; Snædís Björgvinsdóttir; Ioannis Gr Pagonakis; Michael A Urban; Alexander Däpp; Ronny Gunzenhauser; Alexander B Barnes

doi:10.1016/j.jmr.2023.107588

Watch-sized 12 Tesla all-high-temperature-superconducting magnet

J Magn Reson. 2023 Dec:357:107588. doi: 10.1016/j.jmr.2023.107588. Epub 2023 Nov 10.

Authors

Pin-Hui Chen¹, Chukun Gao², Nicholas Alaniva², Snædís Björgvinsdóttir², Ioannis Gr Pagonakis², Michael A Urban², Alexander Däpp², Ronny Gunzenhauser², Alexander B Barnes³

Affiliations

¹ Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2 8093, Zürich, Switzerland. Electronic address: pinhui.chen@phys.chem.ethz.ch.
² Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2 8093, Zürich, Switzerland.
³ Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2 8093, Zürich, Switzerland. Electronic address: alexander.barnes@phys.chem.ethz.ch.

PMID: 37976810
DOI: 10.1016/j.jmr.2023.107588

Abstract

We demonstrate the construction of 7 Tesla and 12 Tesla all high-temperature-superconducting (HTS) magnets, small enough to fit on your wrist. The size of the magnet reduces the cost of fabrication, decreases the fringe field to permit facile siting of magnets, and decreases the stored energy of high field magnets. These small HTS-based magnets are being developed for gyrotron microwave sources for use in high-field nuclear magnetic resonance applications. The 7 Tesla and 12 Tesla magnets employ a no-insulation winding technique and are cooled to 4.2 Kelvin in a liquid helium cryostat. The 7 Tesla magnet is a single pancake coil, made of only 9.4 m of HTS tape, with an inner diameter of 8 mm and an outer diameter of 24 mm. This magnet was charged up to 1168 Amperes, generating a field of 7.3 Tesla. The 12 Tesla magnet is comprised of two pancake coils (inner diameter of 10 mm and outer diameter of 27 mm) connected in series. This magnet reached its maximum field at a current of 850 Amperes.

Keywords: Dynamic nuclear polarization (DNP); High temperature superconductor (HTS); High-field small-bore magnet; No insulation (NI) coil; Superconducting magnet.