Screening Current Simulation Inside YBCO Tape in Charging YBCO Magnet

It was reported that a magnetic field perpendicular to a high temperature superconducting (HTS) tape induced a screening current in the HTS tape of an HTS magnet, and a central magnetic field decreased due to the screening current after the HTS magnet was charged. Hence, it is necessary to investigate the distribution of the screening current inside the HTS tape. This paper reports numerical simulation results about the current distribution and an electrical resistance inside the HTS tape of two HTS magnets, which have different shapes but generate the same central magnetic field, using the finite element method taking into account the E-J characteristic of the HTS tape. The results indicate that the distribution of the perpendicular magnetic field and the electrical resistivity are dependent on the coil shape. The current path in the HTS tape is determined from their distribution. It is concluded that the HTS magnet with a bad shape generates a little large electrical resistance.