Recent studies on no-insulation (NI) winding techniques for high temperature superconducting (HTS) coils have demonstrated that an NI coil has a self-protecting feature: a localized quench heat inside the coil can be automatically diverted in the radial direction owing to the absence of turn-to-turn contacts. The obvious benefits of NI may resolve difficulties in the protection of the HTS coil, which is highly vulnerable to the quench. However, prior to applying the NI technique to the full-scale magnet including several double pancake (DP) coils, it is essential to examine the availability of the self-protecting features between the “axially connected DP coils” as well as between the turn-to-turn contacts in each DP coil. In this study, post-quench behaviors of an HTS magnet including four GdBCO DP coils were investigated through over-current tests. The purpose of the over-current tests was to intentionally quench the HTS magnet, thereby subjecting it to severe operating conditions, and then examine the thermal, electrical, and magnetic integrities of the magnet, validating the intactness of its axial self-protecting feature.
Acknowledgement: This work was supported by the Korea Basic Science Institute under Grant D37614.
|Submitters Country||Republic of Korea|