X-ray cherenkov radiation as a source for relativistic charged particle beam diagnostics

Recent progress in development of accelerator technology for future linear colliders and X-ray free electron lasers has generated an interest in developing novel diagnostics equipment with resolution surpassing tunique beam parameters. Cherenkov radiation (CR) in the X-ray region in the vicinity of the absorption edges is one of the promising sources for relativistic charged particle beam diagnostics. In this paper we have demonstrated that the CR in the X-ray region is naturally monochromatic, because the CR is only generated in the frequency region in the vicinity of the atomic absorption edges, where the well-known Cherenkov condition is fulfilled. This peculiarity can be explained by a resonance behaviour of the permittivity in the frequency range. It will result in the fact that the CR will stand out of any other types of polarisation radiation both on intensity and shape of angular distribution giving a unique opportunity to apply this phenomenon for charged particle beam diagnostics.