Nb/sub 3/Sn phase growth and superconducting properties during heat treatment

The layer growth and superconducting properties of Nb/sub 3/Sn are investigated as a function of the heat treatment (HT) duration and temperature for internal tin and powder-in-tube strands at 650 (degree)C, 700 (degree)C and 750 (degree)C. For all times and temperatures, the Nb/sub 3/Sn layer thickness is measured, the critical current at 4.2 K is tested as a function of magnetic field, and the upper critical field is obtained through parameterization. Results of the layer critical current density are also shown as a function of HT duration and temperature.