Peculiarities of electromagnetic oscillations generated by a charged particle crossing the planar boundary between a conducting medium and a vacuum

The peculiarities of electromagnetic oscillations generated by a charged particle moving rectilinearly and uniformly have been studied when the particle crosses a planar boundary between a conducting medium and a vacuum perpendicular to that boundary. This study is based on the relevant exact analytical solutions of Maxwell equations, and the generalized Drude-Lorentz-Sommerfeld formula has been used for the dielectric function of conducting medium in the numerical calculations. The results of our investigation indicated that a charged particle may generate large amplitude oscillations in an electric field at frequencies wherein the dispersion phenomenon is essential and the real part of the conducting material's dielectric function is negative. The results further revealed that these oscillations are localized at the planar boundary of the conducting medium and a vacuum. The possibility of using this phenomenon to generate electromagnetic radiation at large distances from the surface of a conducting medium of finite size is also discussed