Thermal Stabilization of Ceramic Superconductors

The results of a program to identify candidate dielectric insulation materials for a Ni/YBCO powder-in-tube conductor are presented. Based on literature surveys and thermal property measurements on three rounds of materials, six final ceramic materials are identified. Thermal conductivity and thermal diffusivity, 15–90 K, are the key parameters, and the materials selected have conductivities and diffusivities up to 100 times larger than amorphous materials in this temperature range. Thermal expansion data 41200 K are presented for these materials and for the Ni/YBCO conductor.