Fast charge energy losses in structures with a 2D electron gas

Fast charge energy losses for the excitation of natural oscillations in media with a 2D plasma sheath are studied. A semiconducting (dielectric) cylinder-2D plasma sheath-vacuum system is considered. Dispersion relations describing natural oscillations in such a system are derived. Energy losses of a point charge rectilinearly and uniformly moving over and inside the cylinder are found. The loss of energy by a moving charged ring embracing the system (specifically, a nanotube) is considered.