Characterization of high-current, high-temperature superconductor current lead elements

R.C Niemann,W.E Brockenborough,A.J Rodenbush,D.J Evans,B.L Fisher,P.R Roberts

doi:10.1109/77.620939

Abstract

A conductor element consisting of laminated stack of high temperature superconductor (HTS) powder-in-tube (PIT) tapes is suitable for incorporation into current leads. The details of an application of such conductor elements to a current lead for a SMES system are presented. The fabrication of the laminated-conductor elements made with BSCCO 2223 PIT tapes is described. The critical current measurement method and results for two such conductor elements are presented. Performance was evaluated with variable temperatures and with variable applied fields.

Highlights

Use of high-temperature superconductors (HTSs) for current leads to deliver power to superconductordevices operating at liquid He temperature has the potential to reduce refrigeration loads to values significantly below those achievable with conventional leads, which introduce heat into cryostats by thermal conduction and Joule heating
A lamination of Bi-2223 powder-in-tube (PIT) tapes is suitable as the conductor element of an HTS current lead
Advantages of FIT conductors include high critical transition temperatun?(Tc), high critical current density (Jc),that is relatively insensitive to applied field at low temperature and low applied fields, structural ruggedness with good strain tolerance, adjustability of Ag sheath thermal conductivity by alloying, improved protection capacity in interrupt condition, Fig. 1

Summary

Argonne National Laboratory

Reference to any specific commercial product, proctss, or seryicc by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thenof. The views and opinions of authors expressed do not necessarily state or reflect.those of the United States Government or any agency thereof. J. Rodenbush American Superconductor Corp., Westborough, MA 01581, USA. Additional characterization, which correlates electrical performance a t 77 K and at lower temperatures with applied magnetic fields, provides the current lead designer and the conductor element manufacturer with critical information. For HTS conductor elements comprising a laminated and sintered stack of Bi-2223 PIT tapes having an alloyed Ag sheath, this characterization uses variable applied fields and operating temperatures.

INTRODUCTION

Measurement Facility

Findings

Applied Field Bllc