Analysis of magnetic response of critical state in second-generation high temperature superconductor YBa_2Cu_3O_x wire

摘要

We have measured magnetic response of second-generation high temperature superconductor YBa_2Cu_2O_x wire in perpendicular ac field as a function of temperature. We compare complex ac susceptibility to the calculated susceptibility based on the model of Bean's critical-state response in two-dimensional (2D) disk in perpendicular field and infinitely long cylinder in parallel field. We present a method of linking model and experimental susceptibility. Good agreement of experimental susceptibility with model susceptibility of 2D disk allows noncontact estimation of critical depinning current density and its temperature dependence.