Numerical computation of the interaction between electromagnetic waves andnonlinear superconducting materials

In this paper, we propose a numerical solution to the computation of the in teraction between electromagnetic waves and superconducting materials. A su perconductor is identified as a material with a negative dielectric permitt ivity on the basis of the two-fluid model and an integral-equation formulat ion is developed. The approach takes into account the nonlinear behavior (i .e., the dependence of the material parameters on the internal magnetic fie ld), experimentally observed in previous studies. An iterative process is t hen developed for the numerical solution; the process is based on the disto rted-wave Born approximation. The mathematical formulation of the approach is described and some numerical results concerning the canonical case of a circular cylinder and the behavior of two superconducting transmission line s are reported.