Monochromatic optical Cherenkov radiation of moderately relativistic ions in radiators with frequency dispersion

Optical Cherenkov radiation of moderately relativistic ions in a CVD-diamond plate with frequency dispersion is considered. It has been shown that Cherenkov radiation extracted from the inclined diamond plate to vacuum at a fixed observation angle becomes monochromatic. The wavelength of the spectral line depends on the energy of an ion and on the geometry of an experiment (observation angle and plate inclination angle). An experiment has been proposed to study the monochromatization of Cherenkov radiation on the beam of the JINR Nuclotron for the purpose of its subsequent use in the diagnostics of ion beams. The method can be applied to monitor the NICA ion beams energy.