Dependence of spatial distribution of shielding current density in HTS plate on applied magnetic field profile

The spatial distribution of the shielding current density in the high-Tc superconducting (HTS) plate is investigated numerically. The multiple-thin-layer structure is assumed to modelize the IPTS plate and the flux-flow and flux-creep model is adopted to describe mixed states of the HTS plate. Under these assumptions, the shielding current density flowing in the HTS plate is governed by the integro-differential equations of the scalar potential. By applying the FEM to the spatial discretization of the equations, a nonlinear system of first-order ordinary differential equations is obtained. In order to solve the nonlinear system, the high performance numerical method is employed. A numerical code to integrate the equation has been developed and, by use of the code, the time evolution of the shielding current density is investigated. The results of computations show that the shielding current density becomes more peaked near the edge of the plate with an increase in the frequency of the applied magnetic field. Moreover, it is found that, in the high-frequency region, the phase difference between the applied and the generated magnetic fields approaches to /spl pi/ with an increase in the applied magnetic field.