HTS Current Leads for the NHMFL Series-Connected Hybrid Magnet

Author

Marshall, W.S. ; Bird, M.D. ; Dixon, I.R. ; Gavrilin, A.V. ; Jun Lu ; Miller, G.E. ; Napier, S.E. ; Noyes, P.D. ; Weijers, H.W.

Author_Institution

Nat. High Magn. Field Lab., Tallahassee, FL, USA

Volume

23

Issue

3

fYear

2013

fDate

Jun-13

Firstpage

4800905

Lastpage

4800905

Abstract

A design for the current leads for the National High Magnetic Field Laboratory series-connected hybrid magnet is described. The leads are comprised of a nitrogen vapor cooled resistive heat exchanger section, operating between 296 and 79 K. The heat exchanger uses the “pierced jelly roll” lead technology proven at the National High Magnetic Field Laboratory. A conduction-cooled high-temperature superconducting (HTS) section, operating between 79 and 6 K, uses Sumitomo Type G Bi-2223/Ag5%Au conductors, stacked and soldered into a stainless steel and copper shunt brazement. The leads are located in close proximity to the magnet, and the magnitude of the fringe field on the HTS tapes is 0.37 tesla. The configuration of the HTS section is determined by careful analysis of the self-field and fringe field at the warm end of the HTS section, and by findings from a program of conductor testing.

Keywords

bismuth compounds; calcium compounds; conductors (electric); copper; gold alloys; heat exchangers; high-temperature superconductors; lead compounds; silver alloys; stainless steel; strontium compounds; superconducting magnets; superconducting tapes; HTS current; HTS tapes; NHMFL series-connected hybrid magnet; National High Magnetic Field Laboratory series-connected hybrid magnet; Sumitomo type G Bi-2223-Ag-Au conductors; close proximity; conduction-cooled high-temperature superconducting section; conductor testing program; copper shunt brazement; fringe field; nitrogen vapor; pierced jelly roll lead technology; resistive heat exchanger; soldering; stainless steel; temperature 6 K to 296 K; Conductors; Copper; Critical current; Heating; High temperature superconductors; Magnetic fields; Temperature measurement; Bi-2223; cryogenics; current leads; high-temperature superconductor (HTS);

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2013.2238979

Filename

6407820