Current redistribution around the superconducting-to-normal transition in superconducting Nb-Ti Rutherford cables

G.P. Willering, A.P. Verweij, Herman H.J. ten Kate

Research output: Contribution to journalConference articleAcademic

2 Citations (Scopus)
62 Downloads (Pure)

Abstract

Sufficient thermal-electromagnetic stability against external heat sources is an essential design criterion for superconducting Rutherford cables, especially if operated close to the critical current. Due to the complex phenomena contributing to stability such as helium cooling, inter-strand current and heat transfer, its level is difficult to quantify. In order to improve our understanding, many stability tests were performed on different cable samples, each incorporating several point-like heaters. The current redistribution around the heat front is measured after inducing a local normal zone in one strand of the cable. By using voltage taps, expansion of the normal zone is monitored in the initially quenched strand as well as in adjacent strands. An array of Hall probes positioned at the cable edge is used to scan the self-field generated by the cable by which it becomes possible to estimate the inter-strand current transfer. In this paper it is demonstrated that two different stability regimes can be distinguished depending on the local conditions for local normal zone recovery through heat and current transfer to adjacent strands. It is shown that in the first regime every normal zone will lead to a quench, while in the second regime a normal zone in one strand can recover. Combining the predictions developed using a novel version of the numerical network model CUDI and new measurement results, it is possible to derive characteristic quench decision times as well to calculate and predict the influence of a change in cable parameters.
Original languageEnglish
Article number012119
Number of pages7
JournalJournal of physics: Conference series
Volume97
Issue number1
DOIs
Publication statusPublished - 2008
Event8th European Conference on Applied Superconductivity, EUCAS 2007 - Brussels, Belgium
Duration: 16 Sep 200720 Sep 2007
Conference number: 8

Fingerprint Dive into the research topics of 'Current redistribution around the superconducting-to-normal transition in superconducting Nb-Ti Rutherford cables'. Together they form a unique fingerprint.

  • Cite this