Impedance of a coil surrounding an infinite cylinder with an arbitrary radial conductivity profile

A numerical-analytical method of computing the impedance of a cylindrical coil surrounding a cylindrical workpiece with an arbitrary radial conductivity change is presented, The coil is driven by a constant current source at a fixed frequency, Maxwell's equations are used in the quasi-static approximation and the work-piece is assumed to be nonmagnetic, The solution can be used in the modeling of eddy-current nondestructive evaluation of cylindrical parts