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 becauthe current distribution is strongly se 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. self 1. INTRODUCTION A number of superconducting machines are being developed, such as, SMES (Superconducting Magnetic Energy Storage), NMR (Nuclear Magnetic Resonance), MRI (Magnetic Resonance Image) and magnetic separator [1-3]. Superconducting magnets are used for most of the superconducting machines. To guarantee the cryogenic stability of the superconducting magnets, it is important to estimate precisely the critical current of the superconducting magnets. In a HTS tape which is used for the HTS magnet 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 current distribution is strongly dependent on the applied magnetic field. In order to estimate the critical current of the HTS magnet, it is needed to consider the non-uniform distribution of the current in the HTS tape. Non-uniform current distribution in HTS a tape has not been considered when the critical current has been estimated . Current distribution in a HTS tape has been studied in some papers [4, 5].