A STUDY ON FIELD ERROR OF BULK HTSC STAGGERED ARRAY UNDULATOR ORIGINATED FROM VARIATION OF CRITICAL CURRENT DENSITY OF BULK HTSCS

The bulk high-temperature superconductor staggered array undulator (bulk HTSC SAU) has potential to generate strong periodic magnetic field in short period and to control K value without mechanical gap control structure [1]. However, availability of the bulk HTSC magnets having matched performance of critical current density is a problem to be solved. In this study, we have numerically estimated influence of variation of critical density upon field error using a loop current model based on the Bean model for a type-II superconductor. It was numerically found that the field error was naturally suppressed.