The High Resolution Powder Neutron Diffractometer PUS at the JEEP II Reactor at Kjeller in Norway

The performance of the new Powder Neutron Diffractometer PUS at the 2 MW JEEP II reactor shows the large potential for high resolution powder neutron diffraction even at a low flux reactor. The different components of the instrument are optimised with respect to flexibility and relationship between intensity and resolution. Wavelengths in the range 0.7–2.6 Å are available from a focussing composite Ge monochromator. The detector system consists of position sensitive proportional counters. The temperatures available for experiments range from 7 to about 1600 K. Nearly no malfunctions during the first 2 1/2 years of operation proves the robustness of the complete system. Several experiments show the potential for studies of rather complex crystallographic problems, even with small sample quantities (<200 mg), and timeresolved in-situ type experiments.