Anomalous switching phenomenon in critical-current measurements when using conductive mandrels

Author

Goodrich, L.F. ; Wiejaczka, J.A. ; Srivastava, A.N.

Author_Institution

Nat. Inst. of Stand. & Technol., Boulder, CO, USA

Volume

5

Issue

3

fYear

1995

Firstpage

3442

Lastpage

3444

Abstract

NIST and other laboratories have observed an anomalous switching phenomenon that can occur in critical-current measurements of coiled Nb-Ti and Nb/sub 3/Sn superconductors when mounted on an electrically-conductive measurement mandrel. During acquisition of the voltage-current (V-I) characteristic, large voltage discontinuities are observed, This switching phenomenon results in a multivalued V-I curve, and apparently multiple "critical current" values, An explanation of this phenomenon, some necessary conditions for the switching to occur, as well as methods of detecting the phenomenon are given.<>

Keywords

critical currents; electric current measurement; multifilamentary superconductors; niobium alloys; switching; tin alloys; titanium alloys; type II superconductors; NIST; Nb-Ti; Nb/sub 3/Sn; anomalous switching phenomenon; coiled Nb-Ti superconductor; coiled Nb/sub 3/Sn superconductor; conductive mandrels; critical-current measurements; multiple critical current values; multivalued V-I curve; voltage discontinuities; voltage-current characteristic; Conductivity measurement; Contact resistance; Current measurement; Electric variables measurement; Electrical resistance measurement; Laboratories; Magnetic field measurement; Niobium-tin; Superconductivity; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.413148

Filename

413148