Enhanced trapped field achieved in a superconducting bulk using high thermal conductivity structures following simulated pulsed field magnetization

Rapid heat generation is one of the biggest problems faced in carrying out pulsed field magnetization of (RE)BCO superconducting bulks compared to other methods of magnetization. The effects of various thermal conductivities in the a b -plane ( k a b ) and along the c -axis ( k c ) of a bulk on its trapped field performance following pulsed field magnetization were modelled. The E – J power law was used, coupled with the heat generation, to simulate the effect of anisotropic thermal conductivity combinations on the peak trapped field and total trapped flux. A thermally isolated bulk is not affected so strongly by thermal conductivity, but on cooling the bulk conductively from its base using a cold head, increasing k c significantly enhances both the trapped field and the flux. Embedding highly thermally conducting copper structures in the bulk material was investigated as a practical way to locally increase k a b and k c . The structures investigated increased the trapped field and flux by a maximum of around 30% without increasing the size of the bulk. Different structures can be used depending on whether an application requires the highest trapped field or highest total flux.