Upgrade of Xuanwu: A dual-mode neutron powder diffractometer at CMRR

Neutron diffraction (ND) is a well-established technique of great significance in condensed physics and materials science. Although it has particular advantages against its brother X-ray diffraction (XRD), intensity is still a limiting factor counteracting its application. Herein, we report the upgrade of Xuanwu, a high-resolution neutron powder diffractometer at the China Mianyang Research Reactor (CMRR). A doubly focusing monochromator system made of Si blades is applied to enhance the intensity from 2 × 105n⋅cm−2 ⋅s−1 to 2.39 × 106n⋅cm−2 ⋅s−1 with changeable wavelength. The high-resolution mode with a best resolution 1.6‰ is reserved, which means the working style is optional between high-resolution and high-intensity, making Xuanwu more applicable in expanded scopes.