Tender X-ray beam splitting with high efficiency by use of multilayer grating based on conical diffraction

Abstract

Conical diffraction of a grating differs from the classical type of diffraction because the incident and diffracted wave vectors are not orthogonal to the direction of the grooves, and the light is almost parallel to the grooves. Compared with a grating in the classical type of diffraction, relatively higher diffraction efficiencies will be observed in conical diffraction. And, when the incident beam is perfectly parallel to the grooves of a rectangular grating profile (laminar grating), the symmetry of the setup causes diffraction of the intensity symmetrically around the plane of incidence. A multilayer grating is a grating which is coated with multilayers and can enhance the energy transport efficiency, especially for the tender X-ray range (1-8 keV) that covers a large number of K- and L-edges of medium-Z elements, and M-edges of high-Z elements. A multilayer laminar grating used in the symmetry of conical diffraction can obtain higher efficiency and has the feasibility of the amplitude beam splitting in the tender X-ray range. In this work, using numerical simulation, a possibility of multilayer laminar grating used in the symmetry of conical diffraction for beam splitting in 4.51 keV (Ti Kα1) has been demonstrated, showing a high efficiency and good flexibility of design.