Radiation of charged-particle bunches passing perpendicularly by the edge of a semi-infinite planar wire structure

The radiation of a charged-particle bunch moving perpendicularly to a semi-infinite plane grid composed of thin parallel wires is analyzed using the method of averaged boundary conditions (the period of the grid is assumed to be much less than the wavelengths under investigation). We perform an analysis of the volume radiation and surface waves generated by a bunch of finite length. It is shown that the patterns of the volume radiation fundamentally differ from those that arise in the case of an infinite grid. The properties of the surface waves are similar to the properties of Cherenkov radiation in a three-dimensional wire metamaterial. These waves propagate along the wires at the speed of light in a vacuum and do not diminish with distance (if absorption is negligible). The structure of the surface waves allows for the determination of the size and form of the particle bunches.