Ac loss and thermal runaway of 1 T cryocooler-cooled oxide superconducting pulsed coil

H. Miyazaki, A. Iwamoto, Masataka Iwakuma, K. Funaki, H. Hayashi, A. Tomioka

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We fabricated a 1 T cryocooler-cooled oxide superconducting pulsed coil. It is a 16-layer solenoidal coil wound with an interlayer-transposed 4-strand parallel conductor composed of Bi2223 multifilamentary flat wires. The insulated strands were transposed only between layers to make all strands inductively equivalent. To suppress the temperature rise due to the ac loss, the aluminum nitride(AIN) plates were arranged between layers as heat drains. The pulsed coil was cooled down to 30 K by a single stage cryocooler. It can be operated continuously at 40 K in the 1 T triangular wave operation at 1 Hz. First we studied the temperature dependence of thermal runaway current of the coil under the application of direct transport current. The runaway current was higher than the critical current, which was defined as the current where the electric field of 10-4 V/m was generated on average over the whole length of the conductor. Next we studied the temperature variation of the coil in a sinusoidal operation of 1 Hz. The temperature increment was much more gradual than that in the dc operation. In this paper, we discuss the thermal properties of the cryocooler-cooled oxide superconducting pulsed coil, taking into account the heat generation of ac loss and flux-flow loss and the cooling capacity of a cryocooler.

Original languageEnglish
Pages (from-to)774-777
Number of pages4
JournalIEEE Transactions on Applied Superconductivity
Volume14
Issue number2
DOIs
Publication statusPublished - Jun 1 2004

Fingerprint

Oxides
coils
oxides
strands
Temperature
Aluminum nitride
Critical currents
Heat generation
conductors
Thermodynamic properties
heat generation
aluminum nitrides
Electric fields
Wire
Fluxes
Cooling
temperature
high current
Hot Temperature
interlayers

All Science Journal Classification (ASJC) codes

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

Cite this

Ac loss and thermal runaway of 1 T cryocooler-cooled oxide superconducting pulsed coil. / Miyazaki, H.; Iwamoto, A.; Iwakuma, Masataka; Funaki, K.; Hayashi, H.; Tomioka, A.

In: IEEE Transactions on Applied Superconductivity, Vol. 14, No. 2, 01.06.2004, p. 774-777.

Research output: Contribution to journalArticle

Miyazaki, H. ; Iwamoto, A. ; Iwakuma, Masataka ; Funaki, K. ; Hayashi, H. ; Tomioka, A. / Ac loss and thermal runaway of 1 T cryocooler-cooled oxide superconducting pulsed coil. In: IEEE Transactions on Applied Superconductivity. 2004 ; Vol. 14, No. 2. pp. 774-777.
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