Contour optimization of triangular Laue bent crystal for low wavefront distortion applications.

Crystal bending is widely used in high-energy beamlines for X-ray monochromatisation and focusing. In this research, we propose a wavefront-preserved bending design by changing the section width distribution of the triangle-bent crystal. By developing a theoretical model for the bending of triangular crystals and introducing an iterative approach based on the relationship between the crystal width profile and the bending surface, surface shape accuracy is enhanced over the pre-optimization stage. The simulation findings demonstrate that this method can greatly minimize meridian slope errors within the extended two-dimensional region while also improving the operational dynamic range of the crystal when compared to traditional triangularly bent crystals. In addition, we have investigated the crystal surface properties of the corresponding bending radii under various bending forces. Even incorporating crystal profile defects resulting from standard fabrication errors can also achieve the goal of this design. The verification results obtained using the offline experimental apparatus reveal that the optimized crystal bending system performs significantly better than the pre-optimization scheme in terms of bending accuracy. We confirm the excellent performance and feasibility of our improved bent crystal architecture.