Angular Dependence of Critical Currents for HTS Tapes in Wide Temperature Range and Large Magnetic Fields

Abstract

High temperature superconducting (HTS) tapes usually work in various temperatures and magnetic fields during application. One of the important parameters of HTS tape is the angular dependence of the critical current. Although this phenomenon is well known, rarely studies concerning the angular dependence in the wide temperature range and large magnetic fields simultaneously has ever been shown. To study the angular dependences of critical currents for HTS tapes in wide temperature range and large magnetic fields, the HTS tapes were selected for experiment in this paper. At temperatures of 50-77K, magnetic field strengths of 1-3T and magnetic field directions of $0-360^{\circ}$, the critical currents of the two HTS tapes were measured by four-probe method, and the variation rules of angular dependences were analyzed by calculation. Results show that the increases of temperature and magnetic field weaken the critical currents of HTS tapes at varying degrees, and the critical currents at parallel fields are always larger than that at other degrees. Besides, it can be seen that the increasing temperature has obvious effects on the angular dependences of HTS tapes. The results provide reference for the selection of HTS tapes in superconducting power equipment.