Tcs degradation of ITER TF samples due to fast current discharges. (8th January 2021)

• Record Type: Journal Article
• Authors: Sedlak, Kamil; Bruzzone, Pierluigi; Stepanov, Boris; Mitchell, Neil; Tronza, Vladimir; Vostner, Alexander
• Is Part Of: Superconductor science & technology. Volume 34:Number 2(2021)
• Publication Date: 2021-01-08
• Subjects: TF coils -- conductor testing -- degradation -- quench; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/abc8cd
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: Direct current tests performed in the past on the conductor samples of the toroidal field (TF) ITER coils revealed degradation of current sharing temperature, T cs . The degradation progresses with repetitive electromagnetic loading, and also with thermal cycles between 4.5 K and room temperature. This feature was observed on short samples in SULTAN test facility (EPFL-SPC, Switzerland) as well as in TF Insert Coil tests in CSMC test facility (Naka, Japan). We present three independent observations suggesting that initiation of sample quench followed by a fast current discharge, which normally complements every I c and T cs test in both SULTAN and CSMC, enhances the T cs degradation rate. The exact mechanism of this contribution to the degradation remains unidentified.