Properties of a HTS magnet consisting of pancake windings by using the E-J method

Abstract

Abstract--In a High temperature superconducting (HTS) tape with high aspect ratio, the magnetic field applied to the HTS tape can be different considerably within the HTS tape. The current distribution in the HTS tape is generally non-uniform because the current distribution is strongly dependent on the applied magnetic field. Non-uniform current distribution in a HTS tape has not been properly considered when the critical current has been estimated. This paper shows the calculation of critical current of a HTS magnet consisting of pancake windings. Non-uniform distribution of current in the HTS tape is considered during the calculation of the critical current. Results of calculation show the current concentrated in the middle part of the HTS tape which is used for one pancake winding.

DC modeling and characterization of HTS coils with non uniform current density distribution

“…current of the HTS coil by considering the non-uniform distribution of J, either by considering that the current density is close to its critical value depending on the MFD, i.e. J ≈ J c (B) [7], or by combining the E(J) and J c (B) laws, where generally, the electric field E is considered constant in a tape section, and the convergence criterion is based on an evaluation of the average electric field over the coil [8][9][10].…”