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Omer, M.; Shizuma, Toshiyuki*; Koizumi, Mitsuo; Taira, Yoshitaka*; Zen, H.*; Ogaki, Hideaki*; Hajima, Ryoichi
UVSOR-50, P. 37, 2023/08
no abstracts in English
Segawa, Mariko; Toh, Yosuke; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Hatsukawa, Yuichi; Fukahori, Tokio; Matsue, Hideaki; Oshima, Masumi; Tanimura, Yoshihiko; et al.
Nuclear Instruments and Methods in Physics Research A, 618(1-3), p.153 - 159, 2010/06
Times Cited Count:2 Percentile:22.19(Instruments & Instrumentation)A new measurement system to determine the neutron-capture cross section of a nucleus at 0.008 20 MeV has been installed at the 4 MV Pelletron accelerator laboratory at the facility of radiation standards at Japan Atomic Energy Agency. Pulsed neutrons are produced by bombarding a pulsed proton beam on Li (or H) or a deuteron beam on H. The performance of the new system was studied by measuring discrete rays from neutron capture by Pb and Pb to their low-lying states at several resonances at 10 110 keV using neutrons from Li(p,n)Be. The rays were detected with a good signal-to-noise ratio by means of a highly sensitive anti-Compton NaI(Tl) spectrometer combined with a time-of-flight method. The present study demonstrated good sensitivity of the new system to determine the neutron-capture cross section of a nucleus at keV neutron energy.
Matsushita, Yoshitaka*; Izumi, Fujio*; Kobayashi, Kiyoshi*; Igawa, Naoki; Kitazawa, Hideaki*; Oyama, Yukiko*; Miyoshi, Shogo*; Yamaguchi, Shu*
Nuclear Instruments and Methods in Physics Research A, 600(1), p.319 - 321, 2009/02
Times Cited Count:22 Percentile:80.6(Instruments & Instrumentation)The neutron powder diffraction data of the apatite-type La-silicate LaSiO was measured at 10 K and the Rietveld refinement on the basis of hexagonal P6/m was successfully carried out. The obtained cell parameters were =0.971297(7) nm, and = 0.717950(6) nm. On the Rietveld refinement supported by maximum entropy method, the interstitial oxygen positions show randomly distribution around La2 site, and they may give the driving-force of high ionic conductivity to the main ionic conduction site O4.
Tanaka, Hirokazu*; Hashimoto, Takeji; Koizumi, Satoshi; Ito, Hideaki*; Naka, Kensuke*; Chujo, Yoshiki*
Macromolecules, 41(5), p.1815 - 1824, 2008/03
Times Cited Count:8 Percentile:26.92(Polymer Science)We have investigated the self-assembly formed by palladium acetate (Pd(OAc)) and polyamidoamine dendrimers (GN-NH) in a mixed solvent of methanol and N, N-dimethylformamide. We aim to explore effects of the generation number (GN) and concentration of the dendrimers, [GN-NH], on the self-assembly of the dendrimers (defined hereafter as "templates") and the Pd nanoparticles inside the templates in order to clarify physical factors controlling the self-assembling mechanisms. We found that the templates are formed only when [GN-NH] falls below a critical value and thereby a sufficient amount of Pd(OAc) exists as the binders between the dendrimers. Otherwise dendrimers are molecularly dispersed in solution.
Tanaka, Hirokazu*; Koizumi, Satoshi; Hashimoto, Takeji; Ito, Hideaki*; Sato, Masahide*; Naka, Kensuke*; Chujo, Yoshiki*
Macromolecules, 40(12), p.4327 - 4337, 2007/06
Times Cited Count:31 Percentile:67.13(Polymer Science)We reported the reduction process of palladium(II) acetate, Pd(OAc), and self-assembling process of the resulting palladium atoms, Pd(0)'s, into nanoparticles in the presence of the first-generation polyamidoamine dendrimer (G1-NH) in non-aqueous solution. The process was induced by mixing the following two solutions: (A) Pd(OAc) dissolved in N,N-dimethylformamide (DMF) and (B) the G1-NH dissolved in methanol, under a specific condition of [Pd(OAc)]/[-NH] = 3.3 where [-NH] is mole concentration of the amine groups in the dendrimer in the reaction solution. The reaction and reaction-induced self-assembling process were explored in-situ by means of a combined time-resolved method of small-angle neutron scattering and small-angle X-ray scattering. The method revealed time-evolution of a series of self-assembling processes occurring in the system.
Takamura, Shuichi*; Kado, Shinichiro*; Fujii, Takashi*; Fujiyama, Hiroshi*; Takabe, Hideaki*; Adachi, Kazuo*; Morimiya, Osamu*; Fujimori, Naoji*; Watanabe, Takayuki*; Hayashi, Yasuaki*; et al.
Kara Zukai, Purazuma Enerugi No Subete, P. 164, 2007/03
no abstracts in English
Ishiyama, Hironobu*; Hashimoto, Takashi; Ishikawa, Tomoko*; Watanabe, Yutaka*; Das, S. K.*; Miyatake, Hiroari; Mizoi, Yutaka*; Fukuda, Tomokazu*; Tanaka, Masahiko*; Fuchi, Yoshihide*; et al.
Physics Letters B, 640(3), p.82 - 85, 2006/09
Times Cited Count:32 Percentile:85.01(Astronomy & Astrophysics)The excitation function of the Li(,n)B reaction was measured while identifying the final state event by event in the region of E = 0.7 - 2.6 MeV using a highly efficient detector system and a low-energy Li beam. The results are much improved both in statistics and precisions, and show smaller cross sections than those of previous measurements by a factor of more than 2 in the low-energy region of E 1.5 MeV. A resonance-like structure is found at around E = 0.85 MeV.
Das, S. K.*; Fukuda, Tomokazu*; Mizoi, Yutaka*; Ishiyama, Hironobu*; Miyatake, Hiroari*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Tanaka, Masahiko*; Yoshikawa, Nobuharu*; Jeong, S.-C.*; et al.
AIP Conference Proceedings 847, p.374 - 376, 2006/07
no abstracts in English
Hatsukawa, Yuichi; Osawa, Takahito; Matsue, Hideaki; Segawa, Mariko; Oshima, Masumi; Toh, Yosuke; Kimura, Atsushi; Koizumi, Mitsuo; Furutaka, Kazuyoshi
no journal, ,
The multiple -ray detection method developed for nuclide quantification has achieved better resolution and sensitivity than the ordinary singles -ray detection method. The INAA combined with this method is called NAAMG (Neutron Activation Analysis with Multiple ray detection) and has been successfully applied to various fields. In the case of neutron activation analysis, measurements of -rays from trace elements are strongly interfered by the -rays from isotopes produced from major elements, e.g., Na-24, Mn-56. Therefore chemical separation processes are sometimes required to eliminate the major elements for determination of the trace elements. Measurements of iridium in geological sample were carried out by this method. Samples were irradiated at the JRR-3. Iridium concentrations in several standard rock samples and geological samples were also measured by this method. Fifty to one hundred mg of each sample were sealed in quartz tube and irradiated together with iridium standard. After irradiation, the - coincidence of multiple rays from the Ir-192 was measured with the Ge detectors array, GEMINI-II. rays from about 10 ppt of iridium in geological samples can be detected by this method.
Segawa, Mariko; Toh, Yosuke; Harada, Hideo; Koizumi, Mitsuo; Hatsukawa, Yuichi; Fukahori, Tokio; Matsue, Hideaki; Oshima, Masumi; Nagai, Yasuki*
no journal, ,
no abstracts in English
Shiota, Yoshinori; Akita, Koichi; Suzuki, Hiroyuki*; Kitazawa, Hideaki*; Yokokawa, Tadaharu*; Koizumi, Yutaka*; Harada, Hiroshi*
no journal, ,
no abstracts in English
Suzuki, Shinichi; Yaita, Tsuyoshi; Motokawa, Ryuhei; Koizumi, Satoshi; Okamoto, Yoshihiro; Shiwaku, Hideaki
no journal, ,
no abstracts in English
Ito, Chikara; Naito, Hiroyuki; Ito, Hideaki; Imaizumi, Kazuyuki; Nagai, Akinori; Ito, Keisuke; Nishimura, Akihiko; Oba, Hironori; Wakaida, Ikuo; Sugiyama, Akira; et al.
no journal, ,
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Naito, Hiroyuki; Ito, Chikara; Ito, Hideaki; Imaizumi, Kazuyuki; Ito, Keisuke
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Kitazawa, Hideaki*; Kawamura, Yukihiko*; Keller, L.*; Toyoizumi, Saori*; Terada, Noriki*; Suzuki, Hiroyuki*; Mamiya, Hiroaki*; Doenni, A.*; Lee, S.*; Metoki, Naoto; et al.
no journal, ,
Neutron Scattering study has been carried out in order to reveal the magnetic structure of the antiferromagnet HoPd, which shows giant magnetocaloric effect. We observed short rage magnetic order at k=0.18, 0.18, 0.18 above the antiferromagnetic transition temperature . TbPd also showed magnetic short range correlation above the temperature higher than 2.
Naito, Hiroyuki; Ito, Chikara; Ito, Keisuke; Imaizumi, Kazuyuki; Ito, Hideaki; Nagai, Akinori
no journal, ,
no abstracts in English