The New Neutron Powder Diffractometer with a Multi-Detector System for High-Efficiency and High-Resolution Measurements

Abstract

We describe a multipurpose neutron powder diffractometer for high-efficiency and high-resolution measurements, HERMES, which has been installed at the JRR-3M reactor in Japan Atomic Energy Research Institute. To obtain high-quality data for a short counting time, or with a small sample amount, HERMES has a multi-detector system which consists of 150 3 He neutron detectors and simple window type collimation. The best resolution is Δ2θ of 18' and Δ d / d of 3 ×10 -3 , where 2θ and d are scattering-angle and d -spacing, respectively. The duration of an ordinary powder diffraction experiment is 1–5 h under the present conditions in JRR-3M. Some typical results of powder diffraction experiments and performance are given in this paper. We also show a result of 2D intensity mapping of magnetic diffuse scattering from a single crystal of a spin glass material.