Evaluation of solders for superconducting magnetic shield

Author

Seo, K. ; Nishijima, S. ; Katagir, K. ; Okada, T.

Author_Institution

ISIR, Osaka Univ., Japan

Volume

27

Issue

2

fYear

1991

fDate

3/1/1991 12:00:00 AM

Firstpage

1877

Lastpage

1880

Abstract

A magnetic shield with a superconducting winding has been studied aiming at the practical application of the shield in a magnetic field of higher than 3 T. Tubular magnetic shields have been fabricated with superconducting windings using NbTi multifilamentary composite wires. The shields were impregnated with two kinds of solders (Wood´s metal and indium) to make the electric joint between the wires. In spite of the fact that the superconducting wire provides enough performance to shield the external field of 4 T (I_c=225 A at 4 T), the maximum shielded field of the actual shield was 3.42 T. The superconducting magnetic shield inevitably induces a high-field region near the surface of the shield, and hence the performance of the solder under high field determines the shielding ability. After testing several alloy mixtures to see which provides improved joint properties (joint resistance and therefore I_c), a high-performance shield was fabricated

Keywords

composite superconductors; magnetic shielding; soldering; superconducting devices; 3.42 T; 4 T; In solder; NbTi multifilamentary composite wires; NbTi-In; NbTi-PbSn; PbSn solders; Wood´s metal; critical currents; high-field region; high-performance shield; joint resistance; solders; superconducting magnetic shield; Copper; Indium; Magnetic shielding; Multifilamentary superconductors; Niobium compounds; Superconducting filaments and wires; Superconducting integrated circuits; Superconducting magnets; Superconducting materials; Titanium compounds;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.133563

Filename

133563