AC loss measurements with a cryocooled sample

Author

Schwenterly, S.W. ; Demko, J.A. ; Lue, J.W. ; Walker, M.S. ; Reis, C.T. ; Hazelton, D.W. ; Shi, Xin ; Gardner, M.T.

Author_Institution

Oak Ridge Nat. Lab., TN, USA

Volume

11

Issue

2

fYear

2001

fDate

6/1/2001 12:00:00 AM

Firstpage

4027

Lastpage

4031

Abstract

A new cryostat cooled by a closed-cycle Cryomech GB-37 cryocooler for superconductor measurements at temperatures down to 20 K is described. The sample is conductively coupled to the cold stage so as to minimize vibration and thermal stresses. AC losses have been measured calorimetrically in several high-temperature superconductor coils that have been wound to simulate subscale transformer winding pairs. Stable temperatures down to 20 K were reached on these coils, allowing measurements at practical levels of AC current and I_c. By using short AC current pulses, losses on individual turns could be resolved. Results are reported mainly to showcase the apparatus, measurement procedure, and analytical approach

Keywords

cryostats; high-temperature superconductors; loss measurement; superconducting coils; thermal stresses; transformer windings; vibrations; 77 to 20 K; AC loss measurements; closed-cycle Cryomech GB-37 cryocooler; cryocooled sample; cryostat; high-temperature superconductor coils; measurement procedure; short AC current pulses; subscale transformer winding pairs; superconductor measurements; thermal stresses; vibration; Current measurement; High temperature superconductors; Loss measurement; Pulse transformers; Superconducting coils; Temperature measurement; Thermal conductivity; Thermal stresses; Windings; Wounds;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.947379

Filename

947379