Study on screening current field of quasi-isotropic strand and directly stacked strand at different field orientations

Abstract

REBCO tapes, the so-called second-generation high temperature superconductor, have wide application prospects in electrical engineering and high field magnets because of their high critical current density and superior mechanical and electromagnetic properties. However, a screening current field (SCF) can be induced by the perpendicular component of the magnetic field if the tapes are in a variable magnetic field since the width of the commercial tape is generally more than 2 mm. As a result, the SCF results in an uneven spatial distribution of the magnetic field. In this paper, the SCFs of the quasi-isotropic strand and the directly stacked strand, made of the REBCO tapes, are calculated at 77 K under different orientations of a 300 mT external magnetic field. Then, the experiments are conducted under the same conditions as the simulation. The experimental results are in good agreement with the calculated results. The conclusions of this paper are helpful to understand the SCFs of two kinds of strands and useful in the design of high field magnets in the future.