A new style of neutron facilities coexisting high intensity pulse neutron source (J-PARC/MLF) and steady state neutron from research reactor (JRR-3) is proposed. The coexistence of the pulse and reactor source is the world trend which is inevitable for the next generation neutron science. A sophisticated management and comprehensive user program are important for Japanese neutron community, involving high performance instruments with pulse neutron and steady neutron source with widely spread users. JAEA is the most responsible for the future of neutron science, because of the commitment for both type of neutron source, J-PARC/MLF and JRR-3.
In this article, roles of reactor facilities in the J-PARC age will be discussed. Roles of reactor facilities have to be changed; however, the change should improve the advantages of Japan that there exist reactors and J-PARC simultaneously in East Asia.
The Research Reactor Institute of Kyoto University started basic research on accelerator driven system (ADS) from 2002 for development of innovative nuclear system for nuclear transmutation or neutron source. For this purpose, new FFAG (Fixed Field Alternating Gradient) accelerator complex that can produce pulsed 100MeV proton beam was developed and new experiments coupled with nuclear reactor core at the Kyoto University Critical Assembly (KUCA) were started from 2009, which were the world’s first experiments on ADS with proton. Nuclear characteristics of ADS were measured by changing neutron energy spectrum, and several experiments at ADS cores loaded with thorium were also carried out.
The residual stress remarkably affects fracture strength, fatigue strength and stress corrosion cracking. It is very much important to measure the residual stresses in the materials in order to secure the reliability of structure. One of the big characteristics of neutron is large penetration depth. This feature enables to measure the residual strain or stress inside of structural components and machine parts. In this paper, several industrial applications of residual stress and strain measurements by neutron diffraction would be introduced.
A review of investigations and upgrades during the past decade are presented for the small-angle neutron scattering spectrometer SANS-U owned by the Institute for Solid State Physics, The University of Tokyo at the research reactor (JRR-3) of the Japan Atomic Energy Agency (JAEA), Tokai, Japan. Among the two major upgrades of the SANS-U was highlighted the second upgrade carried out during 2008-2010. This includes the achievement of the increase of the incident beam flux by 3.2 times and of the lowermost Q vector to 3.8 x 10-4 Å-1 owing to an installation of focusing lenses and a high-resolution position sensitive detector consisting of a cross-wired position sensitive photomultiplier tube combined with a ZnS/6LiF scintillator on the SANS-U. The versatility of SANS-U is demonstrated by a variety of accessories and various types of scientific hot topics, including high-pressure experiments, Rheo-SANS, and deformation studies on tough gels, etc.
Two decades have passed since JRR-3 was upgraded. In this article, I will review the present status of crystal and magnetic structure analysis using single crystal samples and reactor-base neutron diffraction. In addition, I will discuss the prospect of this field by comparing new equipments in MLF/J-PARC.
Three types of neutron sources can be used for neutron radiography: radioisotopes, accelerators, and research reactors. Intense neutron beams from research reactors have made high spatial and temporal resolution neutron imaging available and also have made neutron computed tomography practicable.
Since now we have several world-leading neutron science facilities in Japan, enlightenment activities for introducing neutron sciences, for example, to young people is an indispensable issue. Hereafter, we will report present status of the activities based on collaborations between universities and neutron facilities. A few suggestions for future educational activity of JSNS are also shown.
A high position resolution neutron image detector using scnitillators has been developed for IBARAKI Biological Crystal Diffractometer (iBIX) in J-PARC. For this development, many novel technologies were produced on base of original doctrine and idea from the viewpoint of detector researchers who work in neutron facilities. This report describes concept and outline of the development, system design of the detector with the doctrine and idea, signal processing, data acquisition and neutron scintillators. I wish young researchers can understand about neutron imaging using scintillators for research of their science.
The application of neutron spin echo technique on multi-component systems is introduced. As an example, dynamics of polyrotaxane studied by neutron spin echo with contrast variation method is reviewed. In addition, the current status of iNSE is briefly described.