We present results of comprehensive study of electromagnetic behavior of high-temperature superconducting bulk YBCO exposed to time-varying magnetic field. The characteristic of trapped magnetic flux is one of the key factors in application of high-temperature superconducting bulk, such as magnetic levitation system, rotor of motor and bulk magnet. Especially, time inconstancy of trapped flux, such as flux creep, is undesirable for its application system. The relationship between time-varying external magnetic field and trapped flux is investigated experimentally using field-cooled (FC) YBCO disk. Magnetic flux density just above the disk is measured by Hall probes lined up along the disk radius. The magnetic field decay which may be independent of flux creep is observed in the experiment and is influenced significantly by frequency and amplitude of AC external magnetic field. The effect of changing rate of applied magnetic field in field-cool process on trapped flux is also investigated experimentally.
|Number of pages
|IEEE Transactions on Applied Superconductivity
|Published - 2000
|The 16th International Conference on Magnet Tehnolopgy - Tallahassee, FL, USA
Duration: 1999 Sept 26 → 1999 Oct 2