Eddy current loss reduction of superconducting magnets for MAGLEV with a multilayer superconducting sheet

Superconducting conductors and magnets used in the fields of power transmission, generators, MRI, MAGLEV etc. experience AC magnetic fields causing heat generation in the magnets' structure and AC losses in the superconductors. Therefore, AC magnetic shields with wide frequency range in high magnetic fields are desirable to reduce heat generation within the cryogenic region and increase system efficiency. This paper describes the performance of a multilayer superconducting sheet as an AC magnetic field shield, eddy current analysis of MAGLEV coil and eddy current loss measurement of an R&D cryostat with a superconducting magnet. Eddy current loss was reduced to about one fourth of the loss level without a superconducting shield.