Field dependence of critical current density in flat superconductor

Abstract

Surface field of a thin superconductor YBa2Cu3O7-δ in mixed state is measured by a Hall probe array. To reproduce the measured field profiles, shielding current distributions are determined by numerical iterative calculations without supposing any models for field dependence of critical current density Jc (B). Utilizing the estimated local current density and local magnetic field for x – y coordinates, a field variation of current density is plotted. Though any model for Jc (B) is not used for numerical calculations, the field variation roughly shows a dependence like Kim model.