Parametric X-ray radiation (PXR) is a quasi-Cherenkov X-ray radiation generated by a charged particle uniformly moving straightforward through a crystal at angles and frequencies close to Bragg ones, that are determined by the diffraction conditions on crystallographic planes

Important properties of PXR point to the fact that it can be a valuable source of X-ray radiation. It has a high spectral brightness; its spectrum consists of a set of quasimonochromatic lines; it can be emitted in narrow angle reflections to big angles from the direction of particles speed, that lets escape from the beam background and separate from other types of radiation; it is polarised. Finally, all its parameters are easily measured by simple measurement of mutual orientation of the beam, crystallic target and the observer.

This mechanism of radiation was first predicted theoretically in early 1970s in the works by Prof. V.G. Baryshevsky and Prof. I.D. Feranchuk and observed experimentally in joint experiments by BSU staff and Tomsk Institute of nuclear physics in 1985. Currently theoretical and experimental study of PXR is carried out in many scientific centers of the world, and recently a prototype of PXR source was created in PXR. INP BSU staff made a considerable contribution to these studies, among theoretical study of various aspects of this radiation they credit the first experiments on discovery of PXR in the world, this radiation was generated by protons. Also multiwave mode of PXR generation was discovered.

Recentl experiments carried out in INP BSU were dedicated to study of PXR, which is generated by nonrelativistic electrons ( V.G.Baryshevsky et al. Coherent bremsstrahlung and parametric X-ray radiation from nonrelativistic electrons in a crystal. Technical Physics Letters, 2006, volume 32, p. 392–395. DOI: 10.1134/S1063785006050087)