Magnetic Field Angle Dependence of Critical Current in REBCO Tapes Produced by Different Techniques

The critical current of a REBCO tape is a crucial factor in describing its quality. The orientation of applied field has a significant impact on it which is different under different temperatures and amplitudes of applied field. In this paper, we construct a cryogen-free I-c measurement system with a wide range of temperature (20-100 K), magnetic field (0-3 T), angle of the magnetic field (0(degrees)-360(degrees)), and current (0-875 A). The results of the measurements demonstrate that the system can accurately measure the critical current. The magnetic field angle dependency curves of three types of REBCO tapes (MOCVD, MOD, and PLD) are measured. The offset angles near theta = 0(degrees) and 180(degrees), impact of the parallel field's direction, and uplifts near theta = 90(degrees) appear in all REBCO tapes. The effect of temperature and magnetic field on these characteristics depends on the tape's technique. These features are essential in the selection of REBCO tapes for different applications and the structure design of HTS facilities.