Development of a Critical Current Measurement Platform for REBCO Tapes with Micro-Bridges Based on High-Frequency Pulse Current Injection

The critical current (Ic) of high-temperature superconducting (HTS) tapes is typically measured under steady-state magnetic fields using DC power supply. However, such fields are generally limited below 35 T, and generating higher steady-state magnetic fields requires considerable time and resources. In contrast, pulsed-field magnets enable shorter testing time and can exceed 50 T. Thus, we developed a high-frequency pulsed current injection platform for measuringIcof HTS tapes under pulsed magnetic fields. Additionally, etched micro-bridges were employed to proportionally reduce the applied current and mitigate thermal effects that could degrade measurement accuracy. Taking the 50 T, 100-ms flat-top pulsed magnetic fields at the Wuhan National High Magnetic Field Center (WHMFC) as a potential application scenario, the proposed platform integrates a 20 kHz / 6.5-digit multimeter and a mixed-signal oscilloscope for synchronized acquisition. We investigated the effects of injection frequencies (2 kHz to 100 Hz), magnetic fields (0 T to 2 T), and temperatures (65 K to 83 K) on platform performance. The proposed platform was further validated against the conventional DC measurement method at 77 K, self-field.