Numerical simulation of thermal properties of Bi2223 conduction-cooled pulse coil for SMES

M. Iwakuma, H. Miyazaki, I. Tanaka, S. Chigusa, K. Funaki, A. Tomioka, H. Hayashi

Research output: Contribution to journalArticlepeer-review


We studied the thermal and electromagnetic behavior of a conduction-cooled superconducting pulse coil. It was wound with a 4-strand parallel conductor composed of silver sheathed B12223 multifilamentary tapes and impregnated with an epoxy resin. We first investigated the temperature dependence of the thermal runaway current in dc operation. It was higher than the critical current by several tens amps at any temperature from 40 to 90 K. In order to study the mechanism of the thermal runaway, we carried out the numerical simulation of the coil behavior. We found out that the thermal runaway was caused when the heat generation at the winding end close to the cryocooler head where the flux-flow loss is the largest due to perpendicular magnetic field exceeded the cooling through thermal diffusion though the thermal runaway of the coil started at the other end of the winding. If the transport current is smaller than the thermal runaway current at the coil temperature just after applying current, the temperature distribution in the longitudinal direction of the coil varied into a monotonous gradient and the steady thermal flow was established. After that the coil temperature decreased to the balanced one.

Original languageEnglish
Article number1643202
Pages (from-to)1757-1760
Number of pages4
JournalIEEE Transactions on Applied Superconductivity
Issue number2
Publication statusPublished - Jun 2006

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Numerical simulation of thermal properties of Bi2223 conduction-cooled pulse coil for SMES'. Together they form a unique fingerprint.

Cite this