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Rikagaku Kenkyujo (RIKEN) is promoting the maintenance and advanced development of compact neutron source measurement systems with the aim of using "neutrons anytime, anywhere." As of 2022, two RIKEN accelerator-driven compact neutron systems (RANS), RANS and RANS-II, are in constant operation at RIKEN Wako. Summary Aiming for "anytime, anywhere neutrons", the RIKEN compact neutron source system RANS started using neutrons in January 2013. [Extracted from the article]

A sample-motion-synchronized neutron stroboscope is developed using the RIKEN accelerator-based compact neutron source (RANS). When a sample reaches a specified rotation phase, a phase timing signal is generated, triggering a proton pulse at the proton accelerator. A neutron pulse exposes the imaging detector through the sample. By controlling the delay time between the phase signal and the proton pulse timing, the neutron exposure timing is always synchronized with the specific sample rotation phase. A sample rotating at a speed of 1800 RPM is prepared, and clear still images of neutrons are taken. [ABSTRACT FROM AUTHOR]

The RANS (RIKEN Accelerator driven Neutron Source), one of compact accelerator neutron sources (CANS), tries to expand its performance by installing a cold neutron which may provide new opportunities in many applications. RANS is a low power CANS with a proton beam of 7 MeV and 100 µA at maximum. A moderator system was constructed based on results of optimization design study with mesitylene. Recently, we have done performance tests aiming at showing characteristics as cold neutron source. Cryogenic mesitylene moderator was installed on a plug with a new target moderator reflector configuration of RANS. Experiment using a gas electron multiplier (GEM) detector was carried out to measure neutron spectra of the cold moderator. This paper describes performance of the cold moderator in terms of 1) Cold neutron gain of optimization design with respect to a polyethylene moderator, 2) Temperature dependency of cold neutron spectrum flux regarding scattering kernel (SK), and 3) comparison between experiment and calculation. A note is given for comparison between calculations with different SKs available. Also, two-dimensional imaging of cold and thermal neutron spectrum flux on the viewed surface is shown with a pinhole slit configuration. [ABSTRACT FROM AUTHOR]

We have started the development of a transportable neutron salt-meter, we call it RANS-μ, combining a 252Cf neutron source and a prompt gamma neutron activation analysis. Trials of chloride detection measurement with RANS-μ were performed outdoor using removed bridges damaged by chloride attack at an outdoor yard in Public Works Research Institute (PWRI) and a test bridge in Fukushima Robot Test Field. For the measurement at PWRI, the results obtained by RANS-μ were compared with those of the automatic potentiometric titration by drilled powder, and then consistent results were obtained. [ABSTRACT FROM AUTHOR]

To characterize the dose rate distribution in an experimental hall of a RIKEN accelerator-driven compact neutron source (RANS) based on the 9Be(p, n) reaction with 7 MeV proton injection, systematical measurements and calculations for neutron and gamma-ray dose rates by GEometry ANd Tracking (GEANT), Particle and Heavy Ion Transport code System (PHITS), and Monte Carlo N-Particle (MCNP) codes were performed. Calculations always underestimated measurements when proton beam loss effect was not considered. Relatively good agreements were observed among the different simulation codes. To explain the underestimations, the additional dominant neutron and gamma-ray sources due to proton beam loss were identified at the position around exit of the drift tube linac (DTL), made of copper, and the beam pipe from quadrupole (Q) magnets to steering (ST) magnets, made of aluminum, from measurements with placing collimators along linac. The beam loss fractions of 2%–3% on copper and 1% on aluminum, respectively, were the most appropriate estimation. In addition, we proposed the possible measures to reduce the measured total dose rate of $3.8~\mu $ Sv/h at the operator position in the control room, with the addition of a wall at the entrance of experimental hall and extension of borated polyethylene (BPE) at the end of the beam. As a result, the dose rate became 2.5 times lower than the current one. [ABSTRACT FROM AUTHOR]

We studied the feasibility of a portable salt-meter incorporating a prompt gamma neutron activation analysis with a californium-252 neutron source to meet urgent demands for non-destructive methods without pre-processing in large bulk materials such as concrete structures. This technique is aiming at the chloride ion concentration in concrete structures with a depth profile from the surface to steel bar. From the portability point of view, a californium-252 neutron source is adopted and we have performed a preliminary experiment and simulations with a simple geometry. In this paper, we describe the performances of salt detection sensitivities by applying the prompt gamma neutron activation analysis. [ABSTRACT FROM AUTHOR]

In order to improve the instrumental accessibility of neutron diffraction techniques, many emerging compact neutron sources and in‐house neutron diffractometers are being developed, even though the precision level of neutron diffraction experiments performed on such instruments was thought to be incomparable with that of large‐scale neutron facilities. As a challenging project, the RIKEN accelerator‐driven compact neutron source (RANS) was employed here to establish the technical environment for texture measurements, and the recalculated pole figures and orientation distribution functions of an interstitial‐free steel sheet obtained from RANS were compared with the results from another two neutron diffractometers well established for texture measurement. These quantitative comparisons revealed that the precise neutron diffraction texture measurement at RANS has been realized successfully, and the fine region division of the neutron detector panel is invaluable for improving the stereographic resolution of texture measurements. Moreover, through selectively using the parts of the obtained neutron diffraction patterns that exhibit good statistics, the Rietveld texture analysis improves the reliability of the texture measurement to a certain extent. These technical research results may accelerate the development of other easily accessible techniques for evaluation of engineering materials using compact neutron sources, and also help to improve the data‐collection efficiency for various time‐resolved scattering experiments at large‐scale neutron facilities. [ABSTRACT FROM AUTHOR]

Upcoming conferences, workshops and UCANS meetings will show further progress and developments and the present proceedings support the discussions and activities to develop and optimize CANS. The contributions published are grouped around work devoted to the topics of accelerator development, neutron source development, cryogenic moderators and various applications using CANS facilities. The Union for Compact Accelerator-driven Neutron Sources (UCANS) has organized regular meetings to discuss the state of the art and developments on this topic since 2010. [Extracted from the article]

A total stamping simulation system, which enables the advanced study of the formability of stamping parts and the accuracy of assembled parts, has been developed. It can be applied from the vehicle-body-parts design phase to the production preparation phase. The developed system consists of 1) simulation technologies to enable parts designers to evaluate the function and formability of a part, 2) simulation technologies to predict the dimensions of stamping parts with high precision and 3) simulation technologies to obtain parts with high dimensional accuracy after the connection of stamping parts by hemming. The system can be used to drastically reduce the vehicle development period without reducing the dimensional accuracy of parts. [ABSTRACT FROM AUTHOR]

Chloride attack is a serious problem that decreases the durability of concrete structures of bridges and highways. A compact neutron salt meter with a252Cf neutron source and germanium (Ge) gamma-ray detector based on prompt gamma-ray neutron activation analysis (PGNAA) has been proposed to determine the chlorine concentration in concrete structures. The Optimization of the dimensions of its components, such as polyethylene (PE) moderator, graphite reflector, and lead shield, as well as the positions of the 252Cf source and the Ge detector has been performed to make it highly sensitive for the detection of gamma-rays of chlorine, in addition to lightweight and small volume for in situ use. The results demonstrated that gain factors of 2.5 and 2.2 were obtained for gamma-ray intensity of chlorine and chlorine-to-hydrogen ratio (CHR), respectively, whereas the weight and volume became 19.1% and 23.4%, respectively, compared with the reference setup. The effectiveness of optimization was confirmed by preliminary experiments. • A portable device to measure chlorine concentration in concrete based on PGNAA with 252Cf neutron source was proposed. • Optimization was performed by Geant4 code to make it highly sensitive and lightweight. • 10 times gain with respect to detection sensitivity per weight was achieved through the optimization. • Effectiveness of the optimization was validated by experiments. [ABSTRACT FROM AUTHOR]