Effect of YBCO-Coil Shape on the Screening Current-Induced Magnetic Field Intensity

Author

Yanagisawa, Yoshinori ; Nakagome, Hideki ; Uglietti, Davide ; Kiyoshi, Tsukasa ; Hu, Ruixin ; Takematsu, Takuya ; Takao, Tomoaki ; Takahashi, Masato ; Maeda, Hideaki

Author_Institution

Grad. Sch. of Eng., ChibaUniversity, Chiba, Japan

Volume

20

Issue

3

fYear

2010

fDate

6/1/2010 12:00:00 AM

Firstpage

744

Lastpage

747

Abstract

A numerical simulation method which deals with the screening current-induced magnetic field for YBCO coils, including the self field effect induced by the transport current, has been developed. The simulation agrees well with the experimental results for an YBCO solenoid. Based on the numerical simulation, the effect of coil shape on the screening current-induced magnetic field intensity for the YBCO coils has been investigated. The field was demonstrated to reach a maximum if the solenoid corresponds to the minimum-volume design; it amounts to as large as -18% of the central magnetic field. Two major problems must be considered for YBCO coils regarding the screening current: (a) a reduction in the central magnetic field by the screening current and (b) a temporal drift of the apparent magnetic field due to relaxation of the screening current by flux creep. It is suggested that the latter can be suppressed by a current sweep reversal technique.

Keywords

electromagnetic shielding; magnetic relaxation; superconducting coils; superconducting magnets; YBCO solenoid; YBCO-coil shape effect; central magnetic field; minimum-volume design; numerical simulation; screening current relaxation; screening current-induced magnetic field intensity; self field effect; superconducting concentric rings; temporal drift; transport current; Coil shape factor; YBCO coil; screening current-induced magnetic field;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2010.2043240

Filename

5443661