Title :
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
fDate :
6/1/2010 12:00:00 AM
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;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2010.2043240
