Ito, Kanae; Yamada, Takeshi*; Shinohara, Akihiro*; Takata, Shinichi; Kawakita, Yukinobu
Journal of Physical Chemistry C, 125(39), p.21645 - 21652, 2021/10
Okudaira, Takuya; Ueda, Yuki; Hiroi, Kosuke; Motokawa, Ryuhei; Inamura, Yasuhiro; Takata, Shinichi; Oku, Takayuki; Suzuki, Junichi*; Takahashi, Shingo*; Endo, Hitoshi*; et al.
Journal of Applied Crystallography, 54(2), p.548 - 556, 2021/04
Neutron polarization analysis (NPA) for small-angle neutron scattering (SANS) experiments using a pulsed neutron source was successfully achieved by applying a He spin filter as a spin analyzer for the scattered neutrons. The He spin filter covers a sufficient solid angle for performing SANS experiments, and the relaxation time of the He polarization is sufficient for continuous use over a few days, thus reaching the typical duration required for a complete set of SANS experiments. Although accurate evaluation of the incoherent neutron scattering, which is predominantly attributable to hydrogen atoms in samples, is practically difficult using calculations based on the sample elemental composition, the developed NPA approach with consideration of the influence of multiple neutron scattering enabled reliable decomposition of the SANS intensity distribution into the coherent and incoherent scattering components. To date, NPA has not been well established as a standard technique for SANS experiments at pulsed neutron sources. This work is anticipated to greatly contribute to the accurate determination of the coherent neutron scattering component for scatterers in various types of organic sample systems in SANS experiments at J-PARC.
Miura, Daisuke*; Kumada, Takayuki; Sekine, Yurina; Motokawa, Ryuhei; Nakagawa, Hiroshi; Oba, Yojiro; Ohara, Takashi; Takata, Shinichi; Hiroi, Kosuke; Morikawa, Toshiaki*; et al.
Journal of Applied Crystallography, 54(2), p.454 - 460, 2021/04
We developed a spin-contrast-variation neutron powder diffractometry technique that extracts the structure factor of hydrogen atoms, namely, the contribution of hydrogen atoms to a crystal structure factor. Crystals of L-glutamic acid were dispersed in a dpolystyrene matrix containing 4-methacryloyloxy-2,2,6,6,-tetramethyl-1-piperidinyloxy (TEMPO methacrylate) to polarize their proton spins dynamically. The intensities of the diffraction peaks of the sample changed according to the proton polarization, and the structure factor of the hydrogen atoms was extracted from the proton-polarization dependent intensities. This technique is expected to enable analyses of the structures of hydrogen-containing materials that are difficult to determine with conventional powder diffractometry.
Teshigawara, Makoto; Tsuchikawa, Yusuke*; Ichikawa, Go*; Takata, Shinichi; Mishima, Kenji*; Harada, Masahide; Oi, Motoki; Kawamura, Yukihiko*; Kai, Tetsuya; Kawamura, Seiko; et al.
Nuclear Instruments and Methods in Physics Research A, 929, p.113 - 120, 2019/06
A nano-diamond is an attractive neutron reflection material below cold neutron energy. The total neutron cross section of a nano-diamond was derived from a neutron transmission measurement over the neutron energy range of 0.2 meV to 100 meV because total neutron cross section data were not available. The total cross section of a nano-diamond with particle size of approximately 5 nm increased with a decrease in neutron energy to 0.2 meV. It was approximately two orders of magnitude larger than that of graphite at 0.2 meV. The contribution of inelastic scattering to the total cross section was to be shown negligible small at neutron energies of 1.2, 1.5, 1.9, 2.6, and 5.9 meV in the inelastic neutron scattering measurement. Moreover, small-angle neutron scattering measurements of the nano-diamond showed a large scattering cross section in the forward direction for low neutron energies.
Nemoto, Fumiya*; Kofu, Maiko; Nagao, Michihiro*; Oishi, Kazuki*; Takata, Shinichi; Suzuki, Junichi*; Yamada, Takeshi*; Shibata, Kaoru; Ueki, Takeshi*; Kitazawa, Yuzo*; et al.
Journal of Chemical Physics, 149(5), p.054502_1 - 054502_11, 2018/08
Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
Kawamura, Seiko; Oku, Takayuki; Watanabe, Masao; Takahashi, Ryuta; Munakata, Koji*; Takata, Shinichi; Sakaguchi, Yoshifumi*; Ishikado, Motoyuki*; Ouchi, Keiichi*; Hattori, Takanori; et al.
Journal of Neutron Research, 19(1-2), p.15 - 22, 2017/11
Sample environment (SE) team at the Materials and Life Science Experimental Facility (MLF) in J-PARC has worked on development and operation of SE equipment and devices. All the members belong to one sub-team at least, such as Cryogenic and magnet, High temperature, High pressure, Soft matter and special environment including Pulse magnet, Hydrogen environment, Light irradiation and He spin filter. Cryostats, a magnet, furnaces, a VX-6-type Paris-Edinburgh press and a prototype of a Spin-Exchange Optical Pumping (SEOP) based He spin filter for polarized neutron beam experiments are in operation. Furthermore, a prototype of compact power supply for a pulsed magnet system is currently developed. In the J-PARC Research Building, several pieces of equipment for softmatter research such as a rheometer and a gas and vapor adsorption measurement instrument have been prepared.
Oba, Yojiro*; Morooka, Satoshi; Oishi, Kazuki*; Suzuki, Junichi*; Takata, Shinichi; Sato, Nobuhiro*; Inoue, Rintaro*; Tsuchiyama, Toshihiro*; Gilbert, E. P.*; Sugiyama, Masaaki*
Journal of Applied Crystallography, 50(2), p.334 - 339, 2017/04
Noda, Yohei*; Koizumi, Satoshi*; Masui, Tomomi*; Mashita, Ryo*; Kishimoto, Hiromichi*; Yamaguchi, Daisuke; Kumada, Takayuki; Takata, Shinichi; Oishi, Kazuki*; Suzuki, Junichi*
Journal of Applied Crystallography, 49(6), p.2036 - 2045, 2016/12
Matsumoto, Takashi; Morimoto, Yasuyuki; Takahashi, Nobuo; Takata, Masaharu; Yoshida, Hideaki; Nakashima, Shinichi; Ishimori, Yuu
JAEA-Technology 2015-036, 60 Pages, 2016/01
The Enrichment Engineering Facilities of the Ningyo-toge Environmental Engineering Center was constructed in order to establish the technical basis of the uranium enrichment plant in Japan. Uranium enrichment tests, using natural and reprocessed uranium, were carried out from 1979 to 1990 at two types of plants in the facilities. UF handling equipment and Supplemental equipment in these plants are intended to be dismantled by 2019 in order to make places for future projects, for example, inventory investigation, precipitation treatment, etc. This report shows the basic plan of this decommissioning project and presents the current state of dismantling in the first-half of the fiscal year of 2014, with indicating its schedule, procedure, situation, results, and so on. The dismantled materials generated amounted to 37 mesh containers and 199 drums, and the secondary waste generated amounted to 271.4 kg.
Nakano, Shota*; Konno, Soken*; Tomita, Naoto*; Matsuba, Go*; Tominaga, Taiki*; Takata, Shinichi
Microsystem Technologies, 22(1), p.57 - 63, 2016/01
We studied the structural formation process of polyacrylonitrile (PAN) gelation in a wide-spatial scale with the small and wide angle neutron scattering in MLF, J-PARC. In micron-scale structure, light transmittance and gelation time were evaluated. The presence of water in the mixed solvent accelerated the phase separation and gelation. In the opaque-gel case, we observed the nanometer-scaled correlation of crystalline cross-linking points and smooth boundary of two micron-scaled phases due to liquid-liquid phase separation. The correlation length is independent of the annealing time, then the cross-linking point exists locally and micro-gelation occurs during phase separation. By contrast, in the transparent-gel case, the correlation length was found to increase throughout the gelation process, and the entanglements of the polymer chains play a role similar to that of cross-linking points.
Kim, J.*; Fujiwara, Akihiko*; Sawada, Tomohiro*; Kim, Y.*; Sugimoto, Kunihisa*; Kato, Kenichi*; Tanaka, Hiroshi*; Ishikado, Motoyuki*; Shamoto, Shinichi; Takata, Masaki*
IUCrJ, 1(3), p.155 - 159, 2014/05
Using a charge density analysis based on synchrotron radiation X-ray powder diffraction data, we found that the charge carriers only accumulated in the iron layer of the superconducting phase of LaFeAsOF at low temperatures. Analysis of the electrostatic potential distribution revealed the concerted enhancement of the electronic polarization of the As ions and the carrier redistribution.
Arai, Masatoshi; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Nakajima, Kenji; Shibata, Kaoru; Takahashi, Nobuaki; Suzuki, Junichi*; Takata, Shinichi; Yamada, Takeshi*; et al.
Journal of the Physical Society of Japan, 82(Suppl.A), p.SA024_1 - SA024_14, 2013/01
The paper describes developments of neutron scattering instruments in J-PARC neutron facility, which is a short pulse spallation source operated at a repetition rate 25 Hz and has a proton power 1 MW. New concept has been adopted to utilize high intensity coupled moderator even for a high resolution inelastic scattering instruments by taking a pulse shaping chopper system. Advanced technique has been also realized by taking an ability of event-recording system altogether with an improvement of a chopper system, realizing multi-Ei method. The paper also touches upon a general design concept for diffractometers in accordance with the source characteristics.
Matsuishi, Satoru*; Hanna, Taku*; Muraba, Yoshinori*; Kim, S. W.*; Kim, J. E.*; Takata, Masaki*; Shamoto, Shinichi; Smith, R. I.*; Hosono, Hideo*
Physical Review B, 85(1), p.014514_1 - 014514_6, 2012/01
We performed the neutron powder diffraction and synchrotron X-ray diffraction measurements on CeFeAsO(D,H) ( = 0.0-0.48) as a representative of 1111-type family of iron-based superconductors LnFeAsOH ( = lanthanoid). These results strongly suggest that H ions exclusively occupy the oxygen sites in both samples, regardless of the hydrogen species in the starting material.
Shinohara, Takenao; Sakai, Kenji; Oi, Motoki; Kai, Tetsuya; Harada, Masahide; Oikawa, Kenichi; Maekawa, Fujio; Suzuki, Junichi; Oku, Takayuki; Takata, Shinichi; et al.
Nuclear Instruments and Methods in Physics Research A, 651(1), p.121 - 125, 2011/09
no abstracts in English
Matsunaga, Toshiyuki*; Yamada, Noboru*; Kojima, Rie*; Shamoto, Shinichi; Sato, Masugu*; Tanida, Hajime*; Uruga, Tomoya*; Kohara, Shinji*; Takata, Masaki*; Zalden, P.*; et al.
Advanced Functional Materials, 21(12), p.2232 - 2239, 2011/06
Thermal properties of the amorphous and crystalline state of phase-change materials show remarkable differences such as higher thermal displacements and a more pronounced anharmonic behavior in the crystalline phase. These findings are related to the change of bonding upon crystallization.
Harada, Masahide; Oikawa, Kenichi; Oi, Motoki; Kai, Tetsuya; Sakai, Kenji; Maekawa, Fujio; Watanabe, Noboru*; Shinohara, Takenao; Takata, Shinichi
Proceedings of 19th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-19) (CD-ROM), 10 Pages, 2010/07
A neutron beam line NOBORU built at MLF in J-PARC is suitable for imaging experiments due to a large beam size, a short distance from the moderator to the sample position and an adequate experimental room. In order to evaluate suitability for the imaging experiments, we measured neutron spectral intensities and flux distributions at the sample position of NOBORU. We also measured those quantities with use of some filters, collimators and slits equipped on NOBORU. As preliminary experiments for imaging, we measured Bragg edge transmission of some alloys and resonance absorption of some elements. The result showed welded and non-welded areas in an alloy could be clearly distinguished by the Bragg edge transmission. It was also found that several elements in the sample could be distinguished clearly by the resonance absorption method. It could be concluded that NOBORU was very suitable for the imaging experiments at J-PARC.
Suzuki, Junichi; Shinohara, Takenao; Takata, Shinichi; Oku, Takayuki; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; Otomo, Toshiya*; Sugiyama, Masaaki*
Nihon Kessho Gakkai-Shi, 50(1), p.24 - 28, 2008/02
no abstracts in English
Shimada, Kenya*; Higashiguchi, Mitsuharu*; Arita, Masashi*; Namatame, Hirofumi*; Taniguchi, Masaki*; Fujimori, Shinichi; Saito, Yuji; Fujimori, Atsushi; Takata, Yasutaka*; Shin, S.*; et al.
Journal of Magnetism and Magnetic Materials, 310(2, Part1), p.e57 - e58, 2007/03
We have examined the electronic states of the Kondo semiconductor CeRhAs and the semimetal CeRhSb by means of high-resolution photoemission spectroscopy using tunable photon energies from 40 up to 5948 eV. On the basis of the photon-energy dependence ofthe photoionization cross-section, we have elucidated the p-d-f hybridized states in these compounds.
Takata, Takeshi; Koma, Yoshikazu; Sato, Koji; Kamiya, Masayoshi; Shibata, Atsuhiro; Nomura, Kazunori; Ogino, Hideki; Koyama, Tomozo; Aose, Shinichi
Journal of Nuclear Science and Technology, 41(3), 307 Pages, 2004/00
The design study of aqueous reprocessing system has been progressed for the feasibility study on commercialized fast reactor cycle systems. Based on the PUREX process,an aqueous reprocessing process with the addition of a uranium crystallization step and