Wave scattering from graphene-covered circular dielectric wire collections analysed using the single-wire part inversion: diffraction radiation case

We consider infrared (IR)-range diffraction radiation (DR) from finite configurations of circular graphene-covered dielectric nanowires excited by the density-modulated beam of charged particles. The beam velocity is assumed constant, and its field in the free space is considered as the incident one. The characterization of graphene employs the quantum-theory Kubo formalism and the resistive-sheet boundary conditions involving the frequency-dependent graphene surface impedance. To transform the problem into a well-conditioned algebraic equation for the field expansion coefficients, we use the separation of variables in the local coordinates and the addition theorem for the cylindrical functions. This leads to explicit inversion of the single-wire part of the problem, i.e. to the regularization, provides easy control of the accuracy and enables us to study fine resonance effects