Development of engineering diffractometer at J-PARC

An engineering diffractometer for investigations of stresses and crystallographic structures within engineering components is now being developed at J-PARC project. The diffractometer is designed to view a decoupled-poisoned liquid H2 moderator providing neutrons with good symmetrical diffraction profiles in the acceptable wavelength range. The diffractometer will have a primary flight path of 40 m and a secondary flight path of 2.0 m for 90o scattering detector banks, and will include a curved supermirror neutron guide to avoid intensity loss due to the long flight path and to reduce backgrounds from fast neutrons and gamma rays. Therefore, stresses with sufficient accuracies in many engineering studies are quite promising. The diffractometer involves a sample translator which is able to handle large and heavy real industrial-scaled components. Detailed design works are being continuously promoted. The optimization of the diffractometer has been performed with a Monte Carlo simulation, and an appropriate resolution of less than 0.2% in Δd/d has been confirmed