Characteristics of the High Resolution Powder Diffractometer (HRPD) recently installed at JRR-3M are described. The machine is composed of 64 detectors equally spaced at every 2.5 degrees in diffraction angle. The obtained resolution of the machine is 0.2% in Δd/d at best. It is also described that the Wide Angle Neutron Diffractometer (WAND) at HFIR is particularly suited for studing kinetics of the phase transitions in various materials. Some experiments performed with the dif fractometers are reviewed briefly.
