Composite superconducting bulks for efficient heat dissipation during pulse magnetization

Abstract

Pulsed field magnetization is the most practical method of magnetizing a (RE)BCO bulk, however large heat generation limits the trapped field to significantly less than possible using field cooling. Modelling has been used to show that effective heat removal from the bulk interior, using embedded metallic structures, can enhance trapped field by increasing thermal stability. The reported results are for experimental pulsed magnetization of a thin walled YBCO sample with 55 vertical holes embedded with high thermal conductivity wires. A specially designed copper coldhead was used to increase the trapped field and flux of the perforated YBCO by about 12% at 35 K using a multi-pulse magnetization. Moreover, by filling the perforations with copper, the central trapped field was enhanced by 15% after a single-pulse at 35 K. 3D FEM computer model of a perforated YBCO bulk was also developed showing localised heating effects around the perforations during pulse magnetisation.