2-WAVELENGTH SANDWICH MONOCHROMATOR FOR MATERIAL RESEARCH EXPERIMENTS

Properties of a new two-crystal sandwich monochromator based on bent-p erfect silicon crystals are presented. A high-resolution neutron diffr actometer equipped with such Si (1 1 1)-Si (2 2 0) monochromator and d edicated to strain/stress investigations in polycrystalline materials has been built and introduced into routine operation in NPI Rez. Good luminosity of the diffractometer and a sufficiently high-resolution (F WHM of the instrumental Delta d/d-profile can be about 2 x 10(-3) at d = 0.2 nm) permit investigations of more reflection profiles significa ntly improves a reliability of the investigation of both the macro-and microstrains. (C) 1998 Elsevier Science B.V. All rights reserved.