Heat transfer issues in the fabrication and operation of ceramic superconductors

Problems associated with the fabrication and operation of ceramic superconductors are discussed to suggest possible contributions from the heat transfer community that could advance high temperature superconductor technology. Specific fabrication issues include uniform temperature in sintering, speedup of directional solidification methods, uniform substrate temperatures for thin film fabrication, and process control in most wire and tape fabrication methods. Opportunity exists for analyses and novel designs in cryostat current leads, certain insulation problems, and other applications. Use of Be as a stabilizer is suggested in order to improve cryostability at 77 K. In addition, the use of SiC and novel heat transfer mechanisms is suggested for improvement of normal zone propagation velocity.