Determination of the AC losses of Bi-2223 HTS coils at 77 K at power frequencies using a mass boil-off calorimetric technique

Author

Darmann, Frank ; Dou, Shi ; Cook, Chris

Author_Institution

Eng. Center, Australian Supercond., Coniston, NSW, Australia

Volume

13

Issue

1

fYear

2003

fDate

3/1/2003 12:00:00 AM

Firstpage

1

Lastpage

6

Abstract

A mass boil-off measurement system has been used to accurately measure and characterize the ac loss of high-temperature superconductor (HTS) coils at frequencies between 50 and 200 Hz, and in applied ac fields of up to 0.04 T. The mass boil-off calorimeter incorporated a glass cryostat, a copper field coil, and two mass flow meters. The response of the gas flow to a step change in the applied magnetic field was found to have a time constant of about 600 s. Under suitable experimental conditions, it was possible to measure the ac losses of coils with an accuracy of ±0.3 W. The ac loss characteristics of an HTS pancake and two HTS solenoid coils are presented and the accuracy of mass flow calorimetry in liquid nitrogen is reported on.

Keywords

bismuth compounds; calcium compounds; calorimetry; high-temperature superconductors; loss measurement; strontium compounds; superconducting coils; 0.04 T; 50 to 200 Hz; 77 K; AC loss measurement; Bi-2223 high temperature superconductor; Bi₂Sr₂Ca₂Cu₃O; copper field coil; gas flow; glass cryostat; liquid nitrogen; magnetic field; mass boil-off calorimetry; mass flow meter; pancake coil; power frequency; solenoid coil; time constant; Copper; Fluid flow; Fluid flow measurement; Frequency measurement; Glass; High temperature superconductors; Loss measurement; Magnetic field measurement; Solenoids; Superconducting coils;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2003.809828

Filename

1198074