Electromagnetic wave scattering by a crack type defect

Electromagnetic wave diffraction on a crack-type defect is a typical simplest problem in the theory of nondestructive testing. Such a defect can be considered as a thin dielectric scatterer. In the scalar case of a wave diffraction problem we use the term “thin scatterer” to mean cylindrical shell when its largest thickness is much less than the length along the guide. The last one is assumed to be comparable with the excitation wavelength. In this paper we consider three mathematical models of the mentioned diffraction problem. One of them is based, in fact, on the volume integral equations approach