# MT25 Conference 2017 - Timetable, Abstracts, Orals and Posters

27 August 2017 to 1 September 2017
RAI Congress Center, Amsterdam, The Netherlands
Europe/Amsterdam timezone

## Overview of Recent Progress in No-Insulation REBCO Magnet Research

28 Aug 2017, 17:00
15m
G102-103 Room

#### G102-103 Room

Regular 15 minutes Oral Presentation G3 - Stability of Conductors and Coils

### Speaker

Seungyong Hahn (Seoul National University / National High Magnetic Field Lab.)

### Description

For the past few years, notable progress has been made in the no-insulation (NI) high temperature superconductor (HTS) magnet technology. Electromagnetic (thus fast) quench propagation, the key mechanism for the "self-protecting", has been demonstrated in experiments of >100 NI modules and test coils, as well as various numerical simulations. Major drawbacks of the NI technique, including the intrinsic charging delay and non-linear electromagnetic behaviors, have been actively studied; variations of the NI technique together with complementary techniques have been proposed for performance improvement of NI magnets. This paper presents a brief overview of the recent progress in the NI REBCO magnet technology, which include: (1) a 11 T NI-REBCO insert that generated 42.5 T at a coil current density of 1150 $A/mm^2$ in a bore of the 31 T resistive background magnet at the National High Magnetic Field Laboratory (NHMFL); (2) a 20 T all-superconducting magnet consisting of a 13 T NI-REBCO insert and a 7 T NbTi background magnet, which will be on service as the first user magnet in early 2017 at the Applied Superconductivity Center of the NHMFL; (3) partial and metal insulation approaches for faster charging and their "safe" operating conditions without losing the self-protecting feature; (4) active feedback control to mitigate the charging delay and non-linear behavior of an NI coil; (5) "defect-irrelevant" behavior of NI coils at 4.2 K and 77 K.
Acknowledgement: This work was supported by the National High Magnetic Field Laboratory (which is supported by the National Science Foundation under NSF/DMR-1157490), and by the State of Florida.

Submitters Country United States

### Primary author

Seungyong Hahn (Seoul National University / National High Magnetic Field Lab.)

### Co-authors

Mr Iain Dixon (NHMFL-FSU) Mark Bird (FSU) Mr Kyle Radcliff (National High Magnetic Field Laboratory) Mr Thomas Painter (Magnet Science & Technology-NHMFL) Dr Kwanglok Kim (National High Magnetic Field Laboratory) Kwangmin Kim (National High Magnetic Field Laboratory) Dmytro Abraimov (NHMFL) Dr Jan Jaroszynski (National High Magnetic Field Laboratory) Mr Kabindra Bhattarai (Applied Superconductivity Center-NHMFL) David Larbalestier (National High Magnetic Field Laboratory) Mr Xinbo Hu (Applied Superconductivity Center-NHMFL)