Generalization of the Optical Theorem to the Case of Excitation of a Local Obstacle by a Multipole

Resumo

The optical theorem is generalized to the case of excitation of a local body by a multipole. To compute the extinction cross-section, it is sufficient to find the derivatives of the scattered field at the single point where the multipole is located. The relationship obtained in this article makes it possible to test software modules developed for studying wave diffraction on transparent bodies.