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Journal Articles

Polarization analysis for small-angle neutron scattering with a $$^{3}$$He spin filter at a pulsed neutron source

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

 Times Cited Count:0 Percentile:0.01(Chemistry, Multidisciplinary)

Neutron polarization analysis (NPA) for small-angle neutron scattering (SANS) experiments using a pulsed neutron source was successfully achieved by applying a $$^{3}$$He spin filter as a spin analyzer for the scattered neutrons. The $$^{3}$$He spin filter covers a sufficient solid angle for performing SANS experiments, and the relaxation time of the $$^{3}$$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.

Journal Articles

Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

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.

Journal Articles

Nanoscopic structural investigation of physically cross-linked nanogels formed from self-associating polymers

Sekine, Yurina; Endo, Hitoshi*; Iwase, Hiroki*; Takeda, Shigeo*; Mukai, Sadaatsu*; Fukazawa, Hiroshi; Littrell, K. C.*; Sasaki, Yoshihiro*; Akiyoshi, Kazunari*

Journal of Physical Chemistry B, 120(46), p.11996 - 12002, 2016/11

 Times Cited Count:9 Percentile:29.02(Chemistry, Physical)

The detailed structure of a nanogel formed by self-association of cholesterol-bearing pullulans (CHP) was determined by contrast variation small-angle neutron scattering. The decomposition of scattering intensities into partial scattering functions of each CHP nanogel component, i.e., pullulan, cholesterol, and the cross-term between the pullulan and the cholesterol allows us to investigate the internal structure of the nanogel. The effective spherical radius of the skeleton formed by pullulan chains was found to be about 8.1 nm. In the CHP nanogel, there are about 19 cross-linking points where a cross-linking point is formed by aggregation of trimer cholesterol molecules with the spatially inhomogeneous distribution of the mass fractal dimension of 2.6. The average radius of the partial chains can also be determined to be 1.7 nm. As the result, the complex structure of the nanogels is coherently revealed at the nanoscopical level.

Journal Articles

In-situ monitoring of ion-beam luminescence of Si-O-C(-H) ceramics under proton-beam irradiation

Narisawa, Masaki*; Koka, Masashi; Takeyama, Akinori; Sugimoto, Masaki; Idesaki, Akira; Sato, Takahiro; Hokazono, Hiroki*; Kawai, Taketoshi*; Iwase, Akihiro*

Journal of the Ceramic Society of Japan, 123(9), p.805 - 808, 2015/09

Journal Articles

Crystal morphology-dependent graft polymerization in poly(ether ether ketone) films

Hasegawa, Shin; Takahashi, Shuichi*; Iwase, Hiroki*; Koizumi, Satoshi; Onuma, Masato*; Maekawa, Yasunari

Polymer, 54(12), p.2895 - 2900, 2013/05

 Times Cited Count:9 Percentile:32.81(Polymer Science)

Radiation-induced graft polymerization of sulfo-containing styrene derivatives into crystalline poly(ether ether ketone) (PEEK) substrates was carried out to prepare thermally and mechanically stable polymer electrolyte membranes based on an aromatic hydrocarbon polymer, so-called "super-engineering plastics". Graft polymerization of the sulfo-containing styrene, ethyl 4-styrenesulfonate (E4S) into PEEK substrates with degrees of crystallinity (DC) of 11 - 26% gradually progressed, achieving a grafting degree of more than 50% after 72 hours, whereas graft polymerization of the substrates with DC above 26% did not proceed. When morphological change in these films were measured by SAXS, PEEK films with DC larger than 26% showed a new peak at d=14 nm, corresponding to lamella structure. Thus, the suppression of graft polymerization of PEEK films with DC above 26% was due to obstruct of monomer diffusion by the formation of the oriented lamella structure.

Journal Articles

Hierarchical structure analysis of graft-type polymer electrolyte membranes consisting of cross-linked polytetrafluoroethylene by small-angle scattering in a wide-$$Q$$ range

Iwase, Hiroki*; Sawada, Shinichi; Yamaki, Tetsuya; Koizumi, Satoshi; Onuma, Masato*; Maekawa, Yasunari

Macromolecules, 45(22), p.9121 - 9127, 2012/11

 Times Cited Count:17 Percentile:54.11(Polymer Science)

Fundamental understanding of the structure-property relationship of polymer electrolyte membranes (PEM) is prerequisite for a material design satisfying PEM performance requirement. Small-angle scattering in a wide-$$Q$$ range was observed by focusing small-angle neutron scattering (FSANS), small-angle neutron scattering (SANS), and small-angle X-ray scattering (SAXS). The hierarchical structure of the PEM was characterized as being composed of conducting layers (graft domains) in lamellar stacks with 48-57 nm spacing on the surfaces of 480 nm diameter crystallites and ultra-small structures with a 1.7 nm correlation distance of the sulfonic acid groups in the conducting layers. From the change in the SAXS profiles as a function of grafting degrees, it was revealed that the graft domains around the crystallites were connected with the adjoining domains and thus, the PEMs with a higher degree of grafting had conductivity higher than that of Nafion.

Journal Articles

Development of grafted type poly(ether ether ketone) electrolyte membranes; Morphology of PEEK substrate and radiation-induced graft polymerization

Hasegawa, Shin; Chen, J.; Koshikawa, Hiroshi; Iwase, Hiroki*; Koizumi, Satoshi; Onuma, Masato*; Maekawa, Yasunari; Iwase, Hiroki*

Proceedings of 12th International Conference on Radiation Curing in Asia (RadTech Asia 2011) (Internet), p.238 - 239, 2011/06

Radiation-induced graft polymerization of sulfo-containing styrene derivatives into crystalline poly(ether ether ketone) (PEEK) substrates was carried out to prepare thermally and mechanically stable polymer electrolyte membranes based on an aromatic hydrocarbon polymer, so-called "super-engineering plastics". Graft polymerization of the sulfo-containing styrene, ethyl 4-styrenesulfonate (E4S) into PEEK substrates with degrees of crystallinity (DC) of 11 - 26% gradually progressed, achieving a grafting degree of more than 50% after 72 hours, whereas graft polymerization of the substrates with DC above 26% did not proceed. When morphological change in these films were measured by SAXS, PEEK films with DC larger than 26% showed a new peak at d=14 nm, corresponding to lamella structure. Thus, the suppression of graft polymerization of PEEK films with DC above 26% was due to obstruct of monomer diffusion by the formation of the oriented lamella structure.

Journal Articles

Radiation-induced graft polymerization of functional monomer into poly(ether ether ketone) film and structure-property analysis of the grafted membrane

Hasegawa, Shin; Takahashi, Shuichi*; Iwase, Hiroki*; Koizumi, Satoshi; Morishita, Norio; Sato, Ken*; Narita, Tadashi*; Onuma, Masato*; Maekawa, Yasunari

Polymer, 52(1), p.98 - 106, 2011/01

 Times Cited Count:45 Percentile:82.88(Polymer Science)

Radiation-induced graft polymerization of sulfo-containing styrene derivatives into poly(ether ether ketone) (PEEK) substrates was carried out to prepare thermally and mechanically stable polymer electrolyte membranes based on an aromatic hydrocarbon polymer. Graft polymerization of ethyl 4-styrenesulfonate into a 32% crystallinity degree PEEK substrate hardly progressed, whereas graft polymerization into 11% PEEK substrate gradually progressed, achieving a grafting degree of more than 50% after 72 h. From Electron Spin Resonance analysis of irradiated PEEK films, it apparent the graft polymerization initiate from the phenoxy radicals. Small-angle X-ray scattering and small-angle neutron scattering observations clearly showed that the graft-type PEEK membranes possessed ion channel domains with the average distance of 13 nm, being larger than that of Nafion. Furthermore, there was a micro-structure in the ion channels with the average distance of 1.8 nm.

Journal Articles

Preirradiation graft polymerization of styrene in a poly(tetrafluoroethylene) film investigated by time-resolved small-angle neutron scattering

Iwase, Hiroki*; Sawada, Shinichi; Yamaki, Tetsuya; Maekawa, Yasunari; Koizumi, Satoshi

International Journal of Polymer Science, 2011(2011), p.301807_1 - 301807_7, 2011/00

 Times Cited Count:9 Percentile:32.49(Polymer Science)

Preirradiation graft polymerization of styrene in a poly(tetrafluoroethylene) (PTFE) film was examined by time-resolved small-angle neutron scattering (SANS). A crosslinked PTFE film, thickness of which is about 50$$mu$$m, was irradiated by $$gamma$$-ray and immersed in a mixed solvent of styrene monomer and toluene. SANS elucidated that graft polymerization proceeds by two reaction processes (I) and (II). In process (I) at 0$$<t<$$200 min, graft polymerization occurs at an interface between crystalline and amorphous PTFE domains and the grafted polystyrene segregates from PTFE, forming a thin layer with a sharp interface. In process (II) at 200$$<t<$$600 min, grafted PS layer starts to bridge between crystalline domains. At the end of process (II), 40% of total crystalline PTFE domain is covered by the grafted PS chains.

Journal Articles

Calculation of radiation shielding for laser-driven hadron beams therapeutic instrument

Sakaki, Hironao; Nishiuchi, Mamiko; Yogo, Akifumi; Bolton, P.; Hori, Toshihiko; Kondo, Kiminori; Saito, Fumihiro; Ueno, Masayuki; Takahashi, Hiroki; Iwase, Hiroshi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.94 - 96, 2010/05

The concept of a compact ion particle accelerator has become attractive in view of recent progress in laser-driven hadrons acceleration. The Photo Medical Research Centre (PMRC) of JAEA was established to address the challenge of laser-driven ion accelerator development for hadrons therapeutic. In the development of the instrument, it is necessary to do the bench-mark of the amount of the different types of radiation by the simulation code for shielding. The Monte Carlo Particle and Heavy Ion Transport code (PHITS) was used for bench-mark the dose on laser-shot radiations of short duration. The code predicts reasonably well the observed total dose as measured with a glass dosimeter in the laser-driven radiations.

Journal Articles

A Combined method of small-angle neutron scattering and neutron radiography to visualize water in an operating fuel cell over a wide length scale from nano to millimeter

Iwase, Hiroki; Koizumi, Satoshi; Iikura, Hiroshi; Matsubayashi, Masahito; Yamaguchi, Daisuke; Maekawa, Yasunari; Hashimoto, Takeji

Nuclear Instruments and Methods in Physics Research A, 605(1-2), p.95 - 98, 2009/06

 Times Cited Count:31 Percentile:89.51(Instruments & Instrumentation)

We constructed an in-situ and simultaneous observation method as a result of combination between ultra-small-angle neutron scattering and neutron imaging (radiography). With this novel technique, we are able to visualize water distribution or transportation, occurring from micro to macro length scales in a polymer electrolyte fuel cell (PEFC). At a sample position of SANS-J-II at JRR-3, we installed a neutron imaging camera in order to construct an in-situ and simultaneous observation method by USANS and neutron imaging with monochromatized cold neutrons. In addition, in order to selectively observe MEA in a running PEFC by using the in-situ and simultaneous observation method, we need to replace carbon separators which cause strong small-angle scattering as a noise. To reduce this strong background, we replaced the carbon separators with the aluminium ones. As a result, the background scattering was minimized (1/10) as compared to before.

Journal Articles

Bacterium organizes hierarchical amorphous structure in microbial cellulose

Koizumi, Satoshi; Zhao, Y.; Tomita, Yoko*; Kondo, Tetsuo*; Iwase, Hiroki; Yamaguchi, Daisuke; Hashimoto, Takeji

European Physical Journal E, 26(1-2), p.137 - 142, 2008/05

 Times Cited Count:48 Percentile:84.7(Chemistry, Physical)

no abstracts in English

Journal Articles

A Focusing-geometry small-angle neutron scattering instrument with a magnetic neutron lens

Oku, Takayuki; Iwase, Hiroki; Shinohara, Takenao; Yamada, Satoru; Hirota, Katsuya*; Koizumi, Satoshi; Suzuki, Junichi; Hashimoto, Takeji; Shimizu, Hirohiko

Journal of Applied Crystallography, 40(s1), p.s408 - s413, 2007/04

 Times Cited Count:25 Percentile:88.89(Chemistry, Multidisciplinary)

Measuring efficiency and/or angular resolution of small-angle neutron scattering experiments can be improved by focusing neutrons on a detector plane. Thus, a magnetic focusing lens (MNL) have been installed into the SANS instrument, SANS-J-II, of JRR-3 in AEA for the focusing-geometry SANS (FSANS) experiments. The MNL is an extended Halbach-type permanent sextupole magnet. The inner diameter and length of the MNL are 35 mm and 1200 mm, respectively. As the MNL functions as the focusing lens only for the polarized neutron with positive polarity, the incident neutron polarization is set positive by using the supermirror polarizer and the two-coil spin flipper. The intensity distribution of the neutrons focused by the MNL at the detector position was measured by using a high-resolution photomultiplier-based scintillation detector. In this paper, the neutron focusing property of the focusing setup is investigated, and the performance of the FSANS instrument is discussed.

Journal Articles

Wide-$$q$$ observation from 10$$^{-4}$$ to 2.0$AA $^{-1}$$ using a focusing and polarized neutron small-angle scattering spectrometer, SANS-J-II

Iwase, Hiroki; Koizumi, Satoshi; Suzuki, Junichi; Oku, Takayuki; Sasao, Hajime*; Tanaka, Hirokazu*; Shimizu, Hirohiko*; Hashimoto, Takeji

Journal of Applied Crystallography, 40(s1), p.s414 - s417, 2007/04

 Times Cited Count:12 Percentile:76.72(Chemistry, Multidisciplinary)

In order to extend an upper q-limit larger, high-angle He sub-detectors were installed on focusing and polarized neutron small-angle scattering spectrometer (SANS-J-II) at JRR-3, Tokai. Consequently, its upper q-limit was improved from 0.2$AA $^{-1}$$ to 2$AA $^{-1}$$. To quantitatively discriminate spin incoherent scattering from hydrogen or to perform nuclear spin polarization contrast variation, a remanent supermirror analyser is also available on the high-angle sub detector. By combining a focusing ultra-small angle scattering, realized by compound and/or magnetic lens and high resolution area detector, SANS-J-II is able to cover from 3$$times$$10$$^{-3}$$ $AA $^{-1}$$ to 2$AA $^{-1}$$ (four order of magnitude of q), which profits to investigate hierarchically ordered system, found widely in hard, soft and bio-materials.

Journal Articles

Low energy vibrational excitations characteristic of superionic glass

Nakamura, Mitsutaka; Iwase, Hiroki; Arai, Masatoshi; Kartini, E.*; Russina, M.*; Yokoo, Tetsuya*; Taylor, J. W.*

Physica B; Condensed Matter, 385-386(1), p.552 - 554, 2006/11

 Times Cited Count:3 Percentile:18.57(Physics, Condensed Matter)

The mechanism of high ionic conductivity in superionic glass constitute an unsolved problem in the field of science.Here we performed inelastic neutron scattering measurements of superionic glass system (AgI)$$_{x}$$(Ag$$_{2}$$S)$$_{x}$$(AgPO$$_{3}$$)$$_{1-2x}$$ by using MARI spectrometer at ISIS, and found that the $$Q$$-dependence of inelastic intensity in the energy region from 1 to 3 meV of superionic phase glass shows an excess intensity above $$Q$$=1.8$AA$^{-1}$$ compared with insulator phase one. Similar phenomena were also observed in another superionic glass (AgI)$$_{0.5}$$(AgPO$$_{3}$$)$$_{0.5}$$ by using NEAT spectrometer at HMI with high resolution measurement. These results clearly suggest peculiar low energy vibrational excitations should be universal features of superionic glass.

Journal Articles

Focusing and Polarized Neutron ultra-small-angle scattering spectrometer (SANS-J-II) at research reactor JRR3, Japan

Koizumi, Satoshi; Iwase, Hiroki; Suzuki, Junichi; Oku, Takayuki; Motokawa, Ryuhei; Sasao, Hajime*; Tanaka, Hirokazu; Yamaguchi, Daisuke; Shimizu, Hirohiko; Hashimoto, Takeji

Physica B; Condensed Matter, 385-386(2), p.1000 - 1006, 2006/11

 Times Cited Count:38 Percentile:81.15(Physics, Condensed Matter)

no abstracts in English

Journal Articles

Relation between high ionic conductivity and boson peak in superionic glass

Arai, Masatoshi; Iwase, Hiroki; Nakamura, Mitsutaka; Otomo, Toshiya*; Kartini, E.*; Ito, Keiji*; Levett, S. J.*; Bennington, S. M.*

AIP Conference Proceedings 832, p.299 - 302, 2006/05

no abstracts in English

Journal Articles

Scenario to focusing polarized small-angle neutron scattering spectrometer SANS-J-II

Koizumi, Satoshi; Iwase, Hiroki; Tanaka, Hirokazu; Hashimoto, Takeji; Suzuki, Junichi; Oku, Takayuki; Sasao, Hajime*; Shimizu, Hirohiko

Hamon, 14(4), p.266 - 274, 2004/10

no abstracts in English

Oral presentation

Applications of MgF$$_{2}$$ focusing lens to small-angle neutron scattering

Iwase, Hiroki; Koizumi, Satoshi; Oku, Takayuki; Suzuki, Junichi

no journal, , 

Since a small-angle scattering technique detects forward scattering with a narrowly collimated incident beam, a lack of luminance is a crucial problem. In order to overcome it, we utilize a neutron focusing lens of biconcave-shaped MgF$$_{2}$$ single crystal, whose effective area is 25mm. We performed test measurements on small-angle neutron scattering spectrometer SANS-J at JRR-3M, JAERI, with 10m camera length and incident neutron of $$lambda=6.5 mathrm{AA}$$. We successfully extended the lower $$Q _{limit} $$($$Q_{min}$$) down to $$3times10^{-4 }mathrm{AA}^{-1}$$, with a pinhole of 2mm$$phi$$ at the entry of collimator and a pile of 70 lenses at the sample position. With keeping conventional $$Q_{min}=3times10^{-3} mathrm{AA}^{-1}$$, we had intensity gain of $$times3$$ with a pin hole of 20mm$$phi$$ at the entry and 40 lenses at the sample position.

Oral presentation

Microstructures of poly (N-isopropylacrylamide) in water studied by focusing Ultra-Small Angle Neutron Scattering (SANS-J-II)

Koizumi, Satoshi; Motokawa, Ryuhei; Iwase, Hiroki; Hashimoto, Takeji

no journal, , 

no abstracts in English

90 (Records 1-20 displayed on this page)