Development of the theory of diffraction radiation from surfaces with finite conductivity

A solution of the problem on diffraction radiation arising at inclined passage of a point-like charged particle near the thin rectangular screen of finite sizes, finite conductivity, and frequency dispersion is found. The problem on diffraction radiation arising at inclined passage of a charge through a rectangular slit in a conductive screen is solved. For zero slit width, the results obtained completely coincide with the corresponding results of the theory of transition radiation at arbitrary values of the dielectric permittivity and angle of particle incidence on the screen surface. In addition to the diffraction mechanism, expressions obtained for the radiation intensity describe the Cherenkov radiation mechanism.