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Mekaru, Harutaka*; Yoshigoe, Akitaka; Nakamura, Michihiro*; Doura, Tomohiro*; Tamanoi, Fuyuhiko*
ACS Applied Nano Materials (Internet), 2(1), p.479 - 488, 2019/01
Times Cited Count：38 Percentile：83.11(Nanoscience & Nanotechnology)Organosilica nanoparticles are attractive for use as drug delivery systems for cancer therapy. Ideally, the nanoparticles need to degrade in the body after drug delivery to minimize their risk. However, the biodegradation of organosilica nanoparticles has not been thoroughly investigated. In this study, we used X-ray photoelectron spectroscopy and field-emission scanning electron microscopy to investigate the degradation of organosilica nanoparticles by glutathione, a peptide found in cells. Our results indirectly indicate that glutathione is able to reduce the disulfide bonds present in the network of one type of the nanoparticles, promoting dissociation of these nanoparticles. The dissociated nanoparticles form large maple leaf-shaped structures under certain conditions. We consider the formation mechanism of these symmetrical structures.
Shibata, Akira; Wakui, Takashi; Nakamura, Natsuki; Futakawa, Masatoshi; Maekawa, Katsuhiro*; Naka, Michihiro
Zairyo Shiken Gijutsu, 62(1), p.41 - 47, 2017/01
Nuclear reactor fuel cladding material has been gradually replaced from Zircaloy-4 to Zr-Nb alloys such as M5. To reveal the origin of good corrosion resistance of Zr-Nb alloys, evaluation on oxide layer of fuel cladding tube Zircaloy-4 and M5 was performed. Nano-indentation with spherical indenter was performed on oxide layer of those materials. Test results of the indentation were evaluated by the inverse analysis using Kalman filter and Finite Element Method. The results analysis shows that the oxide layer of M5 has more ductility compare from that of Zircaloy 4. Thus, oxide layer of Zircaloy4 could be injured by smaller strain compare from that of M5.
Shibata, Akira; Nakamura, Natsuki; Naka, Michihiro
Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 11 Pages, 2017/00
An earthquake with magnitude 9.0 hit eastern Japan on 11th March 2011. It is known as "The 2011 Great East Japan Earthquake". The JMTR hot laboratory was damaged by the earthquake. This paper describes various damages on the JMTR Hot Laboratory caused by the earthquake. In the concrete cell, an electric lock of the shielding door of a hot cell was broken by the earth quake. Cracks were found in the walls of hot laboratory building. The exhaust stack of JMTR Hot Laboratory is a part of gaseous waste treatment system. Thinning was found at anchor bolts on base of the stack in 2015. When thinning of anchor bolts were investigated, gaps between anchor bolt nuts and flange plate were found. It was concluded that the thinning was caused by water infiltration over a long period of time and the gaps were caused by elongation of thinning part of anchor bolts by series of earthquakes start from the 2011 Great East Japan Earthquake.
Nakamura, Natsuki; Shibata, Akira; Naka, Michihiro
Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 4 Pages, 2017/00
no abstracts in English
Eguchi, Shohei; Takemoto, Noriyuki; Shibata, Hiroshi; Naka, Michihiro; Nakamura, Jinichi; Tanimoto, Masataka; Ito, Haruhiko*
JAEA-Review 2016-001, 31 Pages, 2016/05
JAEA-Review-2016-001.pdf:9.05MB
Since fiscal 2011, a practical training course using the JMTR and other research infrastructures has been provided by Neutron Irradiation Testing Reactor Center for foreign young researchers and engineers in Asian and other countries which are planning to introduce power reactors. The aim of this course is to contribute to the human resource development in nuclear research field and to increase the future use the JMTR. On the other hand, a training course for Japanese young researchers and engineers has been conducted since fiscal 2010. These two separate courses were integrated. In fiscal 2015, this training course was conducted for 2 weeks and 17 young researchers and engineers from 7 countries were participated. They studied about the general outline of nuclear research, current status and R&D about nuclear energy, safety management of nuclear reactor, irradiation behavior of materials and fuels, facilities and technologies for irradiation and post irradiation, and nuclear characteristics of the reactor through lectures and practical trainings. At the end of the course, we had a discussion about the current status and future of energy mix and renewable energies of each country was discussed. The content of this training course in fiscal 2015 is reported in this paper.
Kino, Koichi*; Furusaka, Michihiro*; Hiraga, Fujio*; Kamiyama, Takashi*; Kiyanagi, Yoshiaki*; Furutaka, Kazuyoshi; Goko, Shinji*; Hara, Kaoru; Harada, Hideo; Harada, Masahide; et al.
Nuclear Instruments and Methods in Physics Research A, 736, p.66 - 74, 2014/02
Times Cited Count：31 Percentile：91.8(Instruments & Instrumentation)Hori, Junichi*; Fujii, Toshiyuki*; Fukutani, Satoshi*; Furusaka, Michihiro*; Furutaka, Kazuyoshi; Goko, Shinji*; Harada, Hideo; Hiraga, Fujio*; Igashira, Masayuki*; Kamiyama, Takashi*; et al.
JAEA-Conf 2011-002, p.29 - 34, 2011/09
The neutron capture cross sections of 
Zr, 
Tc and 
Pd have been measured relative to the 
B(n,
) standard cross section by the neutron time-of-flight (TOF) method. Neutron capture 
rays were measured with a 4
Ge spectrometer as a part of the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) installed at the neutron Beam Line No.4 (BL04) of the Material and Life science experimental Facility (MLF) in the Japan Proton Accelerator Research Complex (J-PARC). This paper presents the preliminary results.
Ge spectrometerHarada, Hideo; Goko, Shinji*; Kimura, Atsushi; Ota, Masayuki*; Oshima, Masumi; Kitatani, Fumito; Toh, Yosuke; Furutaka, Kazuyoshi; Kin, Tadahiro; Koizumi, Mitsuo; et al.
Journal of the Korean Physical Society, 59(2), p.1547 - 1552, 2011/08
Times Cited Count：9 Percentile：53.69(Physics, Multidisciplinary)For the improvement of the accuracy on the neutron capture cross sections, a 4 Ge spectrometer was developed. The 4 Ge spectrometer is a unique tool due to its superior energy resolution for studying properties on neutron capture reactions, not only capture cross sections but also resonance identification, -ray intensity distribution, and spin-parity assignment. For example, its performance on the resonance identification was demonstrated using a 
Ag sample. On the measurement of a -ray intensity distribution for each resonance, the results of 
U will be shown. Using the 4 Ge spectrometer, the measurements of neutron capture cross sections were started at the J-PARC/MLF/ANNRI. The preliminary results on the measurements of neutron capture cross sections will be discussed mainly based on measurements of neutron capture cross sections for 
Am, together with related techniques.
Kiyanagi, Yoshiaki*; Kino, Koichi*; Furusaka, Michihiro*; Hiraga, Fujio*; Kamiyama, Takashi*; Kato, Kiyoshi*; Igashira, Masayuki*; Katabuchi, Tatsuya*; Mizumoto, Motoharu*; Oshima, Masumi; et al.
Journal of the Korean Physical Society, 59(2), p.1781 - 1784, 2011/08
Times Cited Count：13 Percentile：62.2(Physics, Multidisciplinary)The project of the comprehensive nuclear data research for the development of the advanced reactor systems had been executed successfully by eight organizations from 2005 to 2009. In this project, we constructed the pulsed neutron beamline that was aimed to obtain neutron capture cross-sections of long-lived fission products and minor actinides accurately. The energy spectra, spatial distributions, and pulses of the beam were studied by measurements and simulation calculations, and they were found to be consistent with those of the beamline design. In this paper, we present the overview of the project and the properties of the neutron beam provided by this beam line.
Kino, Koichi*; Furusaka, Michihiro*; Hiraga, Fujio*; Kamiyama, Takashi*; Kiyanagi, Yoshiaki*; Furutaka, Kazuyoshi; Goko, Shinji*; Harada, Hideo; Harada, Masahide; Kai, Tetsuya; et al.
Nuclear Instruments and Methods in Physics Research A, 626-627, p.58 - 66, 2011/01
Times Cited Count：45 Percentile：95.09(Instruments & Instrumentation)We measured the energy spectra and spatial distributions of the neutron beam of ANNRI beamline at the Japan Proton Accelerator Research Complex / Materials and Life Science Experimental Facility (J-PARC/MLF). Our research team designed and built this beamline to measure nuclear data with high precision. The measurements were performed on three types of beams provided by the beamline in the neutron energy range of 1.5 meV to 10 keV. The energy spectra show a typical feature of para-hydrogen moderator, and the absolute intensities almost agree with predictions based on both a simulation calculation of the JSNS (Japan Spallation Neutron Source) and a neutron transmission calculation of the beamline. The available neutron intensities at 21.5 m are 7.5
10
, 1.610
, and 1.110 n/cm
/sec in the energy ranges of 1.5-25 meV, 0.9-1.1 eV, and 0.9-1.1 keV, respectively, under the 17.5 kW JSNS operation. The measured spatial distributions of the beams formed by three different collimators are consistent with those expected from the collimator-system design of the beamline. The beam sizes in FWHM are about 29, 14, and 11 mm for the three different beam collimators. The edges of the spatial distributions are relatively sharp, enabling us to measure the nuclear data successfully.
Harada, Hideo; Oshima, Masumi; Kimura, Atsushi; Goko, Shinji*; Ota, Masayuki*; Furutaka, Kazuyoshi; Kin, Tadahiro; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; et al.
JAEA-Conf 2010-005, p.9 - 14, 2010/12
The neutron-nucleus reaction instrument (NNRI) was installed at the J-PARC MLF BL04, which was designed for measuring neutron cross sections with a neutron time-of-flight technique. This includes two kinds of capture -ray spectrometers: the 4 Ge spectrometer and the NaI spectrometers. The measurements of neutron capture cross sections for minor actinides and fission products have been started at the NNRI using these spectrometers since 2009. In this paper, the preliminary results and future perspectives are discussed.
Cm resonances using NNRIGoko, Shinji*; Kimura, Atsushi; Harada, Hideo; Oshima, Masumi; Ota, Masayuki*; Furutaka, Kazuyoshi; Kin, Tadahiro; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; et al.
Journal of Nuclear Science and Technology, 47(12), p.1097 - 1100, 2010/12
Times Cited Count：6 Percentile：35.74(Nuclear Science & Technology)To obtain the accurate nuclear data of minor actinides required for a nuclear transmutation system or an innovative nuclear fuel cycle system, measurement of neutron-capture cross section of Cm was performed using NNRI installed at beam line No.4 (BL04) of MLF in J-PARC. Using "4 Ge spectrometer" that is a component of NNRI, neutron time of flight spectra and prompt ray spectra were measured. Then neutron-capture cross section ratios of Cm resonances were derived and compared with the evaluated values of JENDL-3.3. The previous experimental data was measured using a nuclear explosion as a pulsed neutron source, and the present result is the first time in the world that such measurements have been carried out at an accelerator facility. By developing techniques for more detailed analysis and improvement of the experimental conditions, the absolute values of capture cross section are expected to be obtained.
Miyazaki, Itaru*; Shimizu, Toshiaki*; Shibata, Michihiro*; Kawade, Kiyoshi*; Furutaka, Kazuyoshi; Nakamura, Shoji; Sakane, Hitoshi
JNC TY8400 2005-002, 40 Pages, 2005/06
JNC-TY8400-2005-002.pdf:2.69MB
Accurate cross section data for the neutron capture of long-lived fission products (LLFP) are needed for developing a nuclear transmutation technology which reduces radioactive wastes by transmuting nuclides that have half-lives of as long as a few million years to other nuclides that have much shorter half-lives. There are some nuclides, whose cross sections cannot be measured in activation method. Utilization of prompt gamma-rays is expected to solve this problem. The aim of present study was twofold: (i) to measure emission probabilities of the high energy gamma-ray, up to 10MeV, emitted from
N(n, gamma)
N reaction, which are usually used as standards, in order to improve their accuracies and (ii) to develop a measurement method for neutron capture cross sections by using prompt gamma-rays. Emission probabilities of principal prompt gamma-rays fromN(n, gamma)N reaction were determined with 0.2-0.9% errors. For ten nuclides,
Na,
Al,
55 Mn,
Ni,
Cu,
Pr,
W, and
capture cross sections were measured by using prompt gamma-rays and gamma-rays following b-decay. By comparing both cross section values, it was found that emission probabilities of prompt gamma-rays reported in the literatures were systematically larger than those inferred from the cross sections that were determined in activation methods. The cross section of a
Pd (n, gamma)
Pd reaction at thermal energy was measured. Considering transmutation of the nuclide, the cross section ofPd(n, gamma), which is an isotope of palladium, is also necessary. A lower limit of the cross section was determined with 6% accuracy. Additionally, a method of estimating an upper limit was examined by noting similarity of nuclear structures to the neighboring nuclides. It was estimated that the observed lower limit of emission probabilities correspond to 79% of the cross section.
Ge spectrometer at the J-PARC/MLF/NNRIHarada, Hideo; Furutaka, Kazuyoshi; Goko, Shinji; Kimura, Atsushi; Kin, Tadahiro; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; Ota, Masayuki; Oshima, Masumi; et al.
no journal, ,
The measurements of neutron capture cross sections have been started using a 4Ge spectrometer at the neutron nucleus reaction instrument (NNRI) in the J-PARC materials and life science facility (MLF). First set of test measurements using the spectrometer at the J-PARC/MLF/NNRI have been performed for radioactive samples such as Cm-244, etc. The initial test experiments have demonstrated the capability of measuring the neutron capture cross section of Cm-244 with a sample mass of less than 1mg. In this talk, we will report preliminary results of the initial experiments, and discuss the new capability and future perspectives. * Present study is the result of "Study on nuclear data by using a high intensity pulsed neutron source for advanced nuclear system" entrusted to Hokkaido University by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).
Ota, Masayuki; Oshima, Masumi; Kitatani, Fumito; Kimura, Atsushi; Kin, Tadahiro; Koizumi, Mitsuo; Goko, Shinji; Toh, Yosuke; Nakamura, Shoji; Harada, Hideo; et al.
no journal, ,
The neutron energy spectrum at BL04 of J-PARC/MLF was measured by the time-of-flight method. The -ray emitted from B(n,
)
Li reaction was measured by Ge detector with/without resonance filters of Cd, Mn, Co, In and Ag. The results revealed that the background was very low and the neutron energy spectrum could be determined with accuracy by using B(n,)Li reaction.
Ge spectrometer for neutron capture cross section measurementsOshima, Masumi; Ota, Masayuki; Kitatani, Fumito; Kimura, Atsushi; Kin, Tadahiro; Koizumi, Mitsuo; Goko, Shinji; Toh, Yosuke; Nakamura, Shoji; Harada, Hideo; et al.
no journal, ,
no abstracts in English
Ge spectrometer at the J-PARCKimura, Atsushi; Ota, Masayuki; Oshima, Masumi; Kitatani, Fumito; Kin, Tadahiro; Koizumi, Mitsuo; Goko, Shinji; Toh, Yosuke; Nakamura, Shoji; Harada, Hideo; et al.
no journal, ,
no abstracts in English
Kakurai, Kazuhisa; Oku, Takayuki; Hayashida, Hirotoshi; Sakai, Kenji; Shinohara, Takenao; Nakamura, Mitsutaka; Wakimoto, Shuichi; Yamazaki, Dai; Sakasai, Kaoru; Soyama, Kazuhiko; et al.
no journal, ,
