New measurement system based on small-angle neutron scattering for structural analysis of light-responsive materials

Iwase, Hiroki*; Akamatsu, Masaaki*; Inamura, Yasuhiro; Sakaguchi, Yoshifumi*; Morikawa, Toshiaki*; Kasai, Satoshi*; Ouchi, Keiichi*; Kobayashi, Kazuki*; Sakai, Hideki*

Journal of Applied Crystallography, 56(1), p.110 - 115, 2023/02

https://doi.org/10.1107/S1600576722011104

With the increasing importance of light-responsive materials, it is vital to analyze the relationship between function and structural changes induced by light irradiation. Small-angle scattering (SAS) is effective for such structural analysis. However, quantitatively capturing local molecular structure formation and molecular reactions at a scale of less than 1 nm via SAS is difficult. In this study, to analyze the structure of non-equilibrium phenomena in light-responsive materials, a new sample environment has been developed for a time-of-flight small- and wide-angle neutron scattering instrument (TAIKAN), comprising a UV-Vis irradiation system, UV-Vis absorption measurement equipment and photodetector. Simultaneous measurement of small-angle neutron scattering and UV-Vis absorption was achieved. This system was used to demonstrate the in situ observation of UV-Vis irradiation-induced structural change of micelles formed by a light-responsive surfactant sample in an aqueous solution.

Position-encoded automatic cell elevator for BL02, J-PARC MLF

Tominaga, Taiki*; Kobayashi, Makoto*; Yamada, Takeshi*; Matsuura, Masato*; Kawakita, Yukinobu; Kasai, Satoshi*

JPS Conference Proceedings (Internet), 33, p.011095_1 - 011095_5, 2021/03

BB2019-1955.pdf:1.33MB

https://doi.org/10.7566/JPSCP.33.011095

A vertical movement type of sample changer for the neutron spectrometer BL02, J-PARC MLF was developed for our top-loading type cryostat. The sample changer, termed as "PEACE", can control reproducibility of the irradiated position using guides made of polyether ether ketone. The variation between the background scattering profiles of three sample positions was found to be less than plus minus 1.6%. This result is reasonable, considering the deviation of sample position of less than plus minus 0.3 mm from the vertical axis.

Fine-structure analysis of perhydropolysilazane-derived nano layers in deep-buried condition using polarized neutron reflectometry

Akutsu, Kazuhiro*; Kira, Hiroshi*; Miyata, Noboru*; Hanashima, Takayasu*; Miyazaki, Tsukasa*; Kasai, Satoshi*; Yamazaki, Dai; Soyama, Kazuhiko; Aoki, Hiroyuki

Polymers (Internet), 12(10), p.2180_1 - 2180_10, 2020/10

https://doi.org/10.3390/polym12102180

Development of alternative He NDA detector system

Koizumi, Mitsuo; Sakasai, Kaoru; Kureta, Masatoshi; Nakamura, Hironobu

Nihon Genshiryoku Gakkai-Shi ATOMO, 58(11), p.642 - 646, 2016/11

no abstracts in English

Development and demonstration of a Pu NDA system using ZnS/BO ceramic scintillator detectors

Nakamura, Hironobu; Ozu, Akira; Kobayashi, Nozomi*; Mukai, Yasunobu; Sakasai, Kaoru; Nakamura, Tatsuya; Soyama, Kazuhiko; Kureta, Masatoshi; Kurita, Tsutomu; Seya, Michio

Proceedings of INMM 55th Annual Meeting (Internet), 9 Pages, 2014/07

To establish an alternative technique of He-3 neutron detector that is used for nuclear material accountancy and safeguards, we have started an R&D project to develop a new type of neutron detector (Pu NDA system) using ZnS/BO ceramic scintillator with support of Japanese government. The design of the alternative system (ASAS: Alternative Sample Assay System) is basically referenced from INVS (INVentory Sample assay system) which is passive neutron assay system of plutonium and has total 18 He-3 tubes (about 42% of counting efficiency), and the small amount of Pu in the MOX powder or Pu nitrate solution in a vial can be measured. In order to establish the technology and performance after the fabrication of the new detector progresses, we are planning to conduct demonstration activity in the early 2015 experimentally. The demonstration activity implements the confirmation of reproducibility about sample positioning, optimization of detector parameters, counting statistical uncertainty, stability (temperature and -ray change) check and figure of merit (FOM) using check source and actual MOX powder. In addition to that, performance comparison between current INVS and the ASAS are also conducted. In this paper, we present some analytical study results using a Monte-Carlo simulation code (MCNP), entire ASAS design and demonstration plan to prove technology and performance.

Evaluation of light transport property in alternative He-3 neutron detectors using ceramic scintillators by a ray-tracing simulation

Ozu, Akira; Takase, Misao*; Kurata, Noritaka*; Kobayashi, Nozomi*; Tobita, Hiroshi; Haruyama, Mitsuo; Kureta, Masatoshi; Nakamura, Tatsuya; Suzuki, Hiroyuki; To, Kentaro; et al.

Proceedings of 2014 IEEE Nuclear Science Symposium and Medical Imaging Conference; 21st International Symposium on Room-Temperature Semiconductor X-ray and -ray detectors (NSS/MIC 2014), 5 Pages, 2014/00

https://doi.org/10.1109/NSSMIC.2014.7431175

In Japan Atomic Energy Agency, the helium-3 alternative neutron detector using ceramic scintillators for nuclear safeguards is under development with the support of the government. The alternative detector module consists of four components: an aluminum regular square tube, a light reflecting foil put on the inner surface of the square tube, a rectangular scintillator sheet sintered on a glass plate, and two PMTs provided at both ends of the tube. The scintillator sheet is fit on the diagonal inside the square tube. The light transport property of scintillator lights inside the tube influences on the fundamental performance of the alternative detector. Therefore, the properties of the lights emitted on the surface of the scintillator sheet and scintillation lights passing through the glass plate to the PMTs in several arrangements of the scintillator in the tubes were investigated with a ray-tracing simulation. The results are described in comparison with the experimental results.

Development of a ZnS/BO ceramic scintillator neutron detector for safeguards NDA systems

Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru; Suzuki, Hiroyuki; Soyama, Kazuhiko; Kureta, Masatoshi; Ozu, Akira; Takase, Misao; Nakamura, Hironobu; Seya, Michio

Proceedings of INMM 54th Annual Meeting (CD-ROM), 8 Pages, 2013/07

We have developed a neutron detector by using ZnS/BO ceramic scintillator for nuclear safeguards NDA systems. The detector has a simple structure where ZnS/BO ceramic scintillator is implemented in the light reflecting case and two PMTs are connected at either end of it. The ZnS/BO ceramic scintillator was originally developed for a two-dimensional neutron detector in the Japan Proton Accelerator Research Complex in Materials and Life Science Experimental Facility. No organic binder material is used in the scintillator, which makes it suitable to a detector operating under -ray irradiation over a long period of time. A neutron absorption probability can be increased by installing two scintillator strips in cross arrangement. In the presentation present status of detector development including detector design, detection system and experimental results measured with a prototype detector will be presented.

Development plan of Pu NDA system using ZnS ceramic scintillator

Kureta, Masatoshi; Soyama, Kazuhiko; Seya, Michio; Ozu, Akira; Haruyama, Mitsuo; Takase, Misao; Sakasai, Kaoru; Nakamura, Tatsuya; To, Kentaro

Proceedings of INMM 53rd Annual Meeting (CD-ROM), 8 Pages, 2012/07

Alternative techniques to neutron detection by helium-3 for nuclear security and safeguards systems are necessary to be developed since helium-3 shortage is serious. With support of Japanese government (the Ministry of Education, Culture, Sports, Science and Technology), we have started an R&D project of Pu NDA system using ZnS ceramic scintillator. Here we present development plan, production of a new type of ZnS ceramic scintillator experimentally and basic design of a PCAS alternative Pu NDA system. We are planning the demonstration tests using the alternative NDA system comparing with the current PCAS in which the helium-3 counters are installed.

Master plan for the development of ZnS scintillation neutron detectors for NDA

Kureta, Masatoshi; Soyama, Kazuhiko; Seya, Michio; Ozu, Akira; Haruyama, Mitsuo; Nakamura, Tatsuya; To, Kentaro; Sakasai, Kaoru

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-32-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2011/11

Alternative techniques to neutron detection by He-3 for safeguards and nuclear security systems are necessary to be developed since He-3 gas shortage is serious. With support of Japanese government (MEXT), we have started the project of ZnS ceramic scintillation neutron detectors for non-destructive assay (NDA) of Pu in Fresh MOX fuel and other types of nuclear material for a use of safeguards verification. Here we present master plan of the project and feasibility study on neutron absorption probability in our scintillator by using Monte Carlo code.

Heat transfer characteristics of the first wall with graphite sheet interlayer

Masaki, Kei; Miyo, Yasuhiko; Sakurai, Shinji; Ezato, Koichiro; Suzuki, Satoshi; Sakasai, Akira

Fusion Engineering and Design, 85(10-12), p.1732 - 1735, 2010/12

https://doi.org/10.1016/j.fusengdes.2010.05.024

Steady-state research is indispensable to establish scientific and technological basis for the next fusion devices. In JT-60, long pulse operation of up to 65s (OH) with a neutral beam heating power of 12 MW (30s) was conducted to investigate the plasma behavior in several tens of seconds. However, the structure of the JT-60U first wall, which was composed of bolted graphite tiles and backings, restricted the flexibility of the plasma operation, because the first wall was not actively cooled. To improve the heat transfer characteristics of the first wall taking into account the cost, a candidate is to insert a graphite sheet between the graphite tile and the backing plate. Aiming at a design study for next fusion devices, the heat transfer characteristics of the first wall structure were investigated with a variety of graphite sheets and fixing-bolt torque conditions. The first wall mockup used for the experiment was composed of three CFC tiles (125(L) 110(W)24(T) mm for each tile) and a cupper-alloy heat sink (377(L)100(W)20(T) mm) with two cooling channels of 10 mm diameter. Four types of the graphite sheets, 0.1-mm thickness PGS (Pyrolytic Graphite Sheet; Panasoic Co., Ltd), 0.2-mm PF (Perma Foil; Toyo Tanso Co., Ltd) 0.38-mm PF, 0.6-mm PF, were examined in the experiment. The heat load tests of the mockup were performed with the heat fluxes of 1 and 3 MW/m on the JAERI electron beam irradiation stand. The experimental results showed that the structure with 0.1-mm thickness 3 PGSs had the highest heat transfer performance in the experiment. The first wall structure with the PGS sheets withstood the heat flux of 1 MW/m100s. The maximum surface temperature of the CFC tile was 500C. Furthermore, the results indicated that the structure could be used at the steady-state condition with the heat flux of 1 MW/m. In the paper, detail of the results will be presented and discussed.