Possibilities for measurement of nano-crystallites size with use of parametric X-ray radiation

Spectral and angular properties of the parametric X-ray radiation (PXR) of relativistic particles emitted in the backward direction from a thin crystalline layer and polycrystal are considered. The shapes of the natural spectral peak of the PXR from a crystalline ball and spectral distribution of PXR from a polycrystal are estimated. It is shown that the natural spectral peak width determines the PXR spectral peak width emitted in backward direction from crystalline layer and grains with size of nanometer range. The method for measurements of crystalline layer thickness and crystalline grains size of nanometer range with use of spectral peak width of the PXR emitted in the backward direction is discussed.