Residual stress measurement technique using neutron diffraction has been developed with supports of Canadian Neutron Beam Center and JAERI (Present JAEA). As Ibaraki Prefecture installed two neutron diffraction apparatuses in J-PARC MLF, I took office as Senior Director. In 2008, I established Industrial Users Society for Neutron Application. Now a number of member is 50 (2 institutes, 48 companies). For the promotion of industrial application, 10 research groups are organized, two type training sessions are held and delivery courses at the companies are held. These activities lead to the allocated proposals for J-PARC MLF occupy about 30% through from 2008 to 2017. This value is incredibly higher compared with the world’s most advanced experimental facilities.

  The neutron science facility (KENS) at National Laboratory for High Energy Physics was the world first user-oriented facility, started operation in 1980. It was a unique accelerator driven spallation source facility at the time having a solid methane cold source. The Small-angle Neutron Scattering Instrument (SAN) was the first of such kind installed at an accelerator driven neutron source. An array of helium-3 gas tube detectors was used for the main detector bank and the electronics system was developed for it.

  In 1996, a new cold neutron experimental hall was built. Two beamlines were shared by two and three instruments respectively. The small and wide-angle diffractometer Wink and the modified small-angle neutron scattering instrument SWAN were built. The new high resolution powder diffractometer (SIRIUS) was built that had a very large detector banks having over 1,000 PSDs and the performance was almost comparable to that of HRPD at ISIS then.

  Great efforts had been poured into getting budget to build a world leading spallation neutron source similar or larger than ISIS. It started as the Gemini project, changed to JHP and to JHF, eventually became J-PARC and successfully built and operating now.

The High Resolution Chopper Spectrometer (HRC) provides opportunities for dynamical studies of materials in a wide energy-momentum space with high resolution in the world standards. In particular, the option of neutron Brillouin scattering (NBS) makes the HRC different from other chopper spectrometers. Coherent excitations in non-single-crystal samples can be observed with NBS. On the HRC, NBS experiments were made feasible and some results were obtained.

Several detectors have been developed for neutron transmission imaging, but neutron image intensifier (NII) is also an option in terms of field of view and sensitivity. Since NII has a position resolution of less than 0.1 mm, it can be expected to obtain a high-sensitivity, high-gradation fine image with a camera to be combined. In this research, we selected CMOS cameras for industrial applications with linearity in sensitivity as the camera, and examined the performance evaluation of the camera, especially the cooling effect of the sensor which becomes a problem in long time measurement. Based on this result, we developed a portable imaging system that compactly integrates a cooled camera with NII and camera and constructed a system that can be used instantaneously in various facilities.

We studied the structure of polybutadiene rubber (BR) crosslinked with zinc diacrylate (ZDA) to elucidate the structure of the high crosslink density BR (HC-BR) using a contrast variation small-angle neutron scattering (CV-SANS) method. The partial scattering functions of the self-correlation of BR, the self-correlation of ZDA aggregates, and the cross-correlation between BR and ZDA aggregates were successfully evaluated from CV-SANS. The detail analyses of these partial scattering functions revealed the existence of a HC-BR layer around the ZDA aggregates. This is the first time quantitative structural analysis of the HC-BR layer in this rubber material.

Researches on neodymium permanent magnet by small-angle neutron scattering (SANS) have been performed to clarify coercivity mechanism. The observation and analysis techniques enable us to know three-dimensional bulk magnetic domains.

For downsizing of an evaporator used for a car air conditioning, comprehension of refrigerant boiling behavior is required. Because the evaporator is generally made from metal material (e.g. aluminum), there is no way to visualize refrigerant boiling state directly until now. Although numerical simulation and thermoviewer analysis allow estimation of the boiling state, but not enough. We are trying to visualize refrigerant boiling state directly by utilizing neutron imaging, from view points following: Constituent metal material of the evaporator and gas refrigerant are transparent for neutron beam, on the other hand, liquid refrigerant can intercept the neutrons. In this paper, our case study of neutron imaging for refrigerant boiling in an evaporator is disclosed.

A thermal neutron reactor produces neutrons of energies in the range of 1-2 MeV, as a result of a nuclear fission reaction of uranium. Neutrons with this high energy range are not suitable for neutron scattering experiments. Therefore, in a research reactor for neutron beam utilization, a thermal moderator is needed to be installed around the primary source to slow down the neutrons to energy levels of 5 meV to 500 meV. Additionally, almost major research reactors equip also at least one cold neutron source, a special moderator operated at cryogenic temperature, which can slow down neutrons to energy levels lower than 5 meV.