Final physical design of engineering materials diffractometer at the China spallation neutron source

Abstract

Neutron diffraction is a widely utilized technique in detecting microstructures and residual strains in large-scale engineering components. In this study, we present the final physical design of an upcoming neutron diffractometer for engineering materials at the China Spallation Neutron Source. Our primary objective is to minimize the experimental time required for precise diffraction peak determination. To achieve this, the design includes a neutron transport system, a neutron wavelength selection system, a diffracted neutron optical system, and a resolution and intensity regulation system. Notably, we optimized the wavelength bandwidth specifically for scientific experiments, while the neutron flux or integrated peak intensity were optimized through careful considerations of neutron transport. Additionally, we placed great emphasis on ensuring the uniformity of the neutron phase space to enhance measurement accuracy. Moreover, we optimized the combinations of resolution and integrated peak intensity based on the best figure of merit. Consequently, we successfully developed an advanced diffractometer that is poised to offer new capabilities for engineering material studies.