Influence of multiple scattering of relativistic electrons on the linewidth of Parametric X-ray Radiation produced in the extremely Bragg geometry in the absence of photoabsorption

•Multiple scattering of electrons destructively influences on the linewidth of Parametric X-ray Radiation.•There are conditions when photoabsorption effect on the linewidth of Parametric X-ray radiation can be neglected.•Natural linewidth of Parametric X-ray radiation is much smaller than of that affected by scattering process.

The multiple scattering effect on the linewidth of backward Parametric X-ray Radiation (PXR) produced in the extremely Bragg geometry by low energy relativistic electrons traversing a single crystal is discussed. It is shown that there are conditions when the influence of photoabsorption on the linewidth can be neglected, and only the multiple scattering process of relativistic electrons in crystals leads to the PXR lines broadening. Based on obtained theoretical and numerical results for the linewidth broadening caused by multiple scattering of 30 and 50 MeV relativistic electrons in a Si crystal of various thicknesses, an experiment could be performed to help in revealing the scattering effect on the PXR lines in the absence of photoabsorption. This leads to more accurate understanding of the influence of scattering process on the linewidth of backward PXR and helps to better construct a table-top narrow bandwidth X-ray source for both scientific and industrial applications.