Quenching characteristics of YBCO bulk contacts

Koichiro Sawa, Katsuya Fukuda, Kuniyasu Ogawa, Masaru Tomita, Masato Murakami, Naomichi Sakai, Izumi Hirabayashi

Research output: Chapter in Book/Report/Conference proceedingConference contribution


A persistent current switch (PCS) is used for superconducting applications, such as superconducting magnetic energy storage (SMES) system. The authors have proposed a mechanical switch of Y-Ba-Cu-O (YBCO) bulk as a mechanical PCS. In previous study, in order to investigate the contact characteristics of the switch, 50A current tests were performed and the contact resistance between two YBCO contacts was measured by four terminal method. As a result, it became clear that polishing and metal depositing on contact surfaces was effective to reduce the residual resistance, and the authors achieved to reduce this resistance to 0.27ìÙ, which was less than our target value of 1ìÙ. This paper focused on the transfer from superconductive to normal conductive state in the YBCO contacts (quenching characteristics), which was not obtained by former 50A current test. In order to perform this experiment, 150A DC power supply and two kinds of curvature silver contacts (R15 and R7.5) as an anode were introduced. The authors investigated that the relationship between the quench current and the layer thickness of deposited silver on the YBCO surface. And it was also observed whether the curvature radius for silver contact affected the value of quench current. Additionally, the contact area of the sample was analyzed with FEM. The analytical results may lead to the elucidation of a contact mechanism and a quench mechanism.

Original languageEnglish
Title of host publication2008 Proceedings of the 54th IEEE Holm Conference on Electrical Contacts, HOLM 2008
Number of pages6
Publication statusPublished - 2008
Event54th IEEE Holm Conference on Electrical Contacts, HOLM 2008 - Orlando, FL, United States
Duration: 2008 Oct 272008 Oct 29

Publication series

NameElectrical Contacts, Proceedings of the Annual Holm Conference on Electrical Contacts
ISSN (Print)0361-4395


Other54th IEEE Holm Conference on Electrical Contacts, HOLM 2008
Country/TerritoryUnited States
CityOrlando, FL


  • Contact resistance
  • Metal deposition
  • Persistent current switch
  • Quenching
  • YBCO

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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