Voltage Criterion of Transport Critical Current Density for a Bi-Based Superconducting Tape

Lance Horng；K. Chen

Chinese Journal of Physics

36卷2S期（1998 / 04 / 01）

378 - 381

英文

Electric field criteria of transport critical current density for an Ag-sheathed Bi-based superconducting tape are investigated at 77 K. Based on detailed measurements of voltage-current curves, the low level resistance has been observed. The values of the critical current density with the magnetic fields are determined by various criteria down to very low voltage (＜ 10^(-9) V). The transport Jc behavior using a criterion with a power law form is similar to that derived from the magnetic hysteresis. A persistent current loop formed by Bi-2223 tapes has also been fabricated and tested. The persistent current of the loop is found to be about 22.5% of its Ic values with a criterion of 1 μV/cm. The ratio is almost equal to that of critical current density with a power law criterion to 1 μV/cm.