Bi-2212 round wire development for high field applications

[摘要] Oxford Superconducting Technology (OST) has been continuously improving Bi-2212 round wire performance because of its potential for application in high-field magnets (> 25 T). We focused on Bi-2212 wire configuration design, filament densification and reducing carbon and hydrogen contamination to improve the engineering critical current density (JE). Several wire configurations have been developed to meet different wire diameter and operating current requirements. The swaging, cold isostatic pressing (CIP) and over-pressure heat treatment processes have been demonstrated to effectively increase Bi-2212 filament mass density in the final wire and result in high performance over long length. The JEvalues exceeding 550 A/mm2at 4.2 K, 15 T have been achieved on the CIPed 1 m long sample using a 10 bar over-pressure (OP) heat treatment. The twisted Bi-2212 wire significantly reduced ac loss without the critical current degradation.

[发布机构] Oxford Superconducting Technology, Carteret; NJ; 07008, United States^1

[关键词] Carbon and hydrogens;Cold isostatic pressing;Configuration designs;Critical current degradation;Engineering critical current density;Heat treatment process;High-field applications;Superconducting technology