Transient electromagnetic shielding in a system of two coaxial cylindrical shells

An attempt to calculate the transient response of a system of two coaxial cylindrical shells is made. The excitation is a current pulse flowing in a straight filament placed parallel to the common axis of the cylinders, either inside or outside the system. The Laplace transform is used for the solution of the diffusion equation in the complex frequency domain. The field quantities in the various regions of the system and the eddy currents within the conducting medium of the shells are determined. The inverse Laplace transform in the time domain is obtained by applying an FFT algorithm.