Magnetization loss properties of thin superconducting tapes with field-dependent critical current

AC losses are numerically evaluated in thin superconducting tapes exposed to an external magnetic field perpendicular to their broad face under the assumption of the critical state model including the field dependence of a critical current density. When the thickness of tape is much smaller than the width, the electromagnetic fields are determined by obtaining the distribution of the magnetic field perpendicular to the tape face and the current density integrated over the tape thickness. Nonlinear integral equations for the perpendicular field are numerically solved at each step during a cycle of external field, and the magnetization losses are finally estimated from the product of local electric field and current density. The influences of the field dependence of critical current density on the losses are discussed quantitatively.