Angular Distribution of Polarized X-Ray Cherenkov Radiation at Grazing Incidence Angles

The spectral-angular characteristics of transition and Cherenkov radiation arising during the passage of fast charged particles through an absorbing medium at grazing incidence angles to the interface are considered. When particles escape from a target in this geometry, radiation is polarized both in the radiation plane and orthogonal to it. With an increase in the emission angle relative to the normal to the surface, the angular distribution of the radiation becomes asymmetric, the intensity of the Cherenkov-radiation component with longitudinal polarization increases significantly, and the angular width decreases. Since in the X‑ray region near absorption the spectral density of Cherenkov radiation has a pronounced maximum, the effect of radiation at grazing incidence angles of particles from the target has serious prospects for becoming an important tool in the creation of sources of polarized oriented hard electromagnetic radiation.