Study of second-generation high-temperature superconducting magnets: the self-field screening effect

Min Zhang, Weijia Yuan, David K. Hilton, Matthieu Dalban Canassy, Ulf P. Trociewitz

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Second-generation high-temperature superconductors (2G HTS) have high current density in very high magnetic fields. They are good candidates for high field magnets, especially when the magnetic field exceeds the critical fields of low-temperature superconductors. However, the thin and flat geometry of these conductors allows persistent screening currents (or shielding currents) to flow in the conductors. The screening currents caused by the ramping of applied current to the coil is identified as the self-field screening effect. The screening-current-induced magnetic field changes the magnetic field distribution of the magnet, and it also generates drift. This paper employs both experimental and numerical methods to study the mechanism of self-field screening currents for 2G HTS magnets. A 2G HTS magnet was constructed and tested, and a finite element model was built based on the magnet. The comparison between calculation and measurement is presented with detailed analysis. Current distributions inside the HTS magnet are calculated to illustrate the effects of screening. The screening-current-induced magnetic field is quantified by comparing the magnetic field distribution with a baseline copper model. The model is also used to explain the mechanism of the current sweep strategy, which can be used to effectively eliminate screening currents.

Original languageEnglish
Article number095010
Number of pages10
JournalSuperconductor Science and Technology
Volume27
Issue number9
DOIs
Publication statusPublished - 13 Aug 2014

    Fingerprint

Keywords

  • finite element modeling
  • high field magnets
  • HTS magnet
  • screening current
  • YBCO

Cite this