Speaker
Description
The development of new high-field superconducting magnets is significantly constrained by the limiting critical properties of superconducting coated conductors (CCs). A major challenge is that REBCO tapes have high critical current densities. It is essential to create micro-bridges on REBCO tapes to test the critical current at low temperatures and high fields. However, pulsed high magnetic fields exceeding 50T generated within just milliseconds present technical challenges for the measurement of critical current. Current studies have assumed that the effect of micro-bridges on tapes is the same at 77 K self-field and at low temperatures and high fields. In this study, we develop a specialized measurement platform for determining the superconducting critical current of tapes with micro-bridges. This platform injects high-frequency, high-precision pulse currents lasting less than 100 milliseconds during the flat-top phase of pulsed high magnetic fields, enabling accurate measurement of the critical current. We compared the critical current measurements of the tapes obtained under a wide range of magnetic fields and temperatures using both DC and pulse current, thus verifying the effectiveness of the proposed platform. Our study provides a more systematic investigation of the impact of micro-bridges on critical currents and lays an important basis for more accurate measurements of critical currents at low temperatures and high fields.
