Dual barrier for the suppression of residual resistance degradation in chrome-plated niobium-tin strands

Author

Gregory, E. ; Gulko, E.A. ; Pyon, T. ; Sumption, M.D. ; Collings, E.W.

Author_Institution

IGC/Adv. Supercond., Waterbury, CT., USA

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

1921

Lastpage

1924

Abstract

For large fusion magnet applications it has been suggested that the Nb/sub 3/Sn superconductor strand be chrome plated to reduce the sintering tendency and to increase the electrical resistance between the strands. Unfortunately, this chrome plating appears to degrade the RRR after the reaction heat treatment. In addition to the normal Nb/sub 3/Sn material with a barrier separating the copper stabilizer from the rest of the conductor, materials have been made with a second barrier close to the surface. One had 10% and the other 20% by volume of copper on the outside of this external barrier. The variation of the RRR of chrome-plated lengths of these material has been explored for a range of different heat treatments and their significance to TPX and ITER magnets is discussed.<>

Keywords

chromium; electric resistance; fusion reactor design; fusion reactor materials; fusion reactors; heat treatment; niobium compounds; superconducting magnets; tin compounds; type II superconductors; Cr-plated Nb/sub 3/Sn strands; ITER magnets; Nb/sub 3/Sn superconductor strand; Nb/sub 3/Sn-Cr; TPX magnets; dual barrier; electrical resistance; fusion reactors; large fusion magnet applications; reaction heat treatment; residual resistance degradation suppression; sintering tendency; type II superconductors; Conducting materials; Copper; Degradation; Electric resistance; Heat treatment; Magnetic separation; Niobium; Niobium-tin; Superconducting magnets; Tin;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.402958

Filename

402958