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Journal Articles

Measurements of the $$^{243}$$Am neutron capture and total cross sections with ANNRI at J-PARC

Kimura, Atsushi; Nakamura, Shoji; Terada, Kazushi*; Nakao, Taro*; Mizuyama, Kazuhito*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; et al.

Journal of Nuclear Science and Technology, 56(6), p.479 - 492, 2019/06

Journal Articles

Measurements of gamma-ray emission probabilities in the decay of americium-244g

Nakamura, Shoji; Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Iwamoto, Osamu; Harada, Hideo; Uehara, Akihiro*; Takamiya, Koichi*; Fujii, Toshiyuki*

Journal of Nuclear Science and Technology, 56(1), p.123 - 129, 2019/01

 Percentile:100(Nuclear Science & Technology)

Accurate data of $$gamma$$-ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by $$gamma$$-ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces $$^{244}$$Am after neutron capture. The 744-keV $$gamma$$-ray decaying from the ground state of $$^{244}$$Am has a relatively large $$gamma$$-ray emission probability c.a. 66%, however, its uncertainty is as large as 29%. The uncertainty of the $$gamma$$-ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the $$gamma$$-ray emission probability was measured by using an activation method and an examined level structure of $$^{244}$$Cm. In this study, the emission probability of 744-keV $$gamma$$ ray was derived as 66.5$$pm$$1.1%, and its uncertainty was improved from 29% to 2%.

Journal Articles

Measurements of neutron total and capture cross sections of $$^{241}$$Am with ANNRI at J-PARC

Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Nakamura, Shoji; Mizuyama, Kazuhito*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; et al.

Journal of Nuclear Science and Technology, 55(10), p.1198 - 1211, 2018/10

 Times Cited Count:1 Percentile:38.14(Nuclear Science & Technology)

Journal Articles

Angular distribution of $$gamma$$ rays from neutron-induced compound states of $$^{140}$$La

Okudaira, Takuya*; Takada, Shusuke*; Hirota, Katsuya*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Nagamoto, Kosuke*; Nakao, Taro*; Okada, Anju*; Sakai, Kenji; et al.

Physical Review C, 97(3), p.034622_1 - 034622_15, 2018/03

Journal Articles

Characterization of germanium detectors for the measurement of the angular distribution of prompt $$gamma$$-rays at the ANNRI in the MLF of the J-PARC

Takada, Shusuke*; Okudaira, Takuya*; Goto, Fumiya*; Hirota, Katsuya*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Nakao, Taro*; Sakai, Kenji; Shimizu, Hirohiko*; et al.

Journal of Instrumentation (Internet), 13(2), p.P02018_1 - P02018_21, 2018/02

Journal Articles

Mn$$_{2}$$VAl Heusler alloy thin films; Appearance of antiferromagnetism and exchange bias in a layered structure with Fe

Tsuchiya, Tomoki*; Kobayashi, Ryota*; Kubota, Takahide*; Saito, Kotaro*; Ono, Kanta*; Ohara, Takashi; Nakao, Akiko*; Takanashi, Koki*

Journal of Physics D; Applied Physics, 51(6), p.065001_1 - 065001_7, 2018/02

 Times Cited Count:1 Percentile:100(Physics, Applied)

Journal Articles

Resonance analysis of cross section data measured by J-PARC/MLF using the modified REFIT code

Mizuyama, Kazuhito; Iwamoto, Nobuyuki; Iwamoto, Osamu; Terada, Kazushi; Nakao, Taro

JAEA-Conf 2017-001, p.163 - 168, 2018/01

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

Technical developments for accurate determination of amount of samples used for TOF measurements

Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Kimura, Atsushi; Iwamoto, Osamu; Harada, Hideo; Takamiya, Koichi*; Hori, Junichi*

EPJ Web of Conferences (Internet), 146, p.03019_1 - 03019_4, 2017/09

 Times Cited Count:2 Percentile:4.05

The research project entitled "Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC)" has been started to improve the reliability of the neutron cross section date of MAs. In order to obtain accurate cross section data, it is indispensable to determine the amount of MA sample accurately and non-destructively. However, the uncertainty concerning the amount of sample is not assured in some cases. Therefore, as a part of the AIMAC project, this study is aimed to development the technique for accurate determination of the amount of samples by two different methods: $$gamma$$-ray spectroscopic method and calorimetric method. This contribution presents the developed techniques together with results obtained by two independent techniques.

Journal Articles

Developments of a new data acquisition system at ANNRI

Nakao, Taro; Terada, Kazushi; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; Hori, Junichi*

EPJ Web of Conferences (Internet), 146, p.03021_1 - 03021_4, 2017/09

 Times Cited Count:2 Percentile:4.05

A new data acquisition system (DAQ system) in J-PARC Materials and Life Science Experimental Facility (MLF) ANNRI was developed. Increasing beam power of MLF in recent years allows beam line users to obtain high quantity experimental data yields. Compared to 2008, more than 20 times beam current is achieved in 2015. For the purpose to correspond strong beam power of MLF, a new DAQ system for the array of the Ge detectors in ANNRI is developed. The DAQ system is also going to be used for processing signals from a Li glass detector, which is under development at ANNRI for measurement of total neutron cross sections. Commissioning experiment of a new DAQ system at ANNRI was performed by using 0.1mmt Au sample with 500kW J-PARC proton beam power. An applicability of time-of-flight method for both neutron capture and total cross-sections measurements was checked. ADC and TDC nonlinearity, energy resolution, multi-channel coincidence and dead time performance for the array of the Ge detectors were also evaluated. The dead time value for Ge detectors was successfully decreased to 1/4 from the previous DAQ system with minor deterioration on energy resolution. The author would like to thank the accelerator and technical staff at J-PARC for operation of the accelerator and the neutron production target and for the other experimental supports. Present study includes the result of "Research and Development for accuracy improvement of neutron nuclear data on minor actinides" entrusted to the Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).

Journal Articles

Research and development for accuracy improvement of neutron nuclear data on minor actinides

Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Mizuyama, Kazuhito; Igashira, Masayuki*; Katabuchi, Tatsuya*; et al.

EPJ Web of Conferences (Internet), 146, p.11001_1 - 11001_6, 2017/09

 Times Cited Count:1 Percentile:14.04

Journal Articles

Measurements of $$gamma$$-ray emission probabilities of $$^{241,243}$$Am and $$^{239}$$Np

Terada, Kazushi; Nakamura, Shoji; Nakao, Taro; Kimura, Atsushi; Iwamoto, Osamu; Harada, Hideo; Takamiya, Koichi*; Hori, Junichi*

Journal of Nuclear Science and Technology, 53(11), p.1881 - 1888, 2016/11

 Times Cited Count:2 Percentile:57.25(Nuclear Science & Technology)

$$gamma$$-ray emission probabilities of $$^{241,243}$$Am and $$^{239}$$Np have been precisely measured with $$gamma$$- and $$alpha$$-ray spectroscopic methods. The activities of $$^{243}$$Am samples were determined by measuring alpha particles using a Si semiconductor detector. $$gamma$$-rays emitted from the samples were measured with a planar type High-Purity Germanium (HPGe) detector. An efficiency curve of the Ge detector was derived with uncertainties of 0.7% from 50 to 1332 keV and 1.3% below 50 keV by combining measured efficiencies and Monte Carlo simulation. The $$gamma$$-ray emission probabilities for the major $$gamma$$-rays of these nuclides were determined with uncertainties less than 1.2%.

Journal Articles

Distributions of neutron yields and doses around a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions

Satoh, Daiki; Kajimoto, Tsuyoshi*; Shigyo, Nobuhiro*; Itashiki, Yutaro*; Imabayashi, Yoichi*; Koba, Yusuke*; Matsufuji, Naruhiro*; Sanami, Toshiya*; Nakao, Noriaki*; Uozumi, Yusuke*

Nuclear Instruments and Methods in Physics Research B, 387, p.10 - 19, 2016/11

 Times Cited Count:2 Percentile:57.25(Instruments & Instrumentation)

Double-differential neutron yields from a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions were measured at emission angles of 15$$^{circ}$$, 30$$^{circ}$$, 45$$^{circ}$$, 60$$^{circ}$$, 75$$^{circ}$$, and 90$$^{circ}$$ using the neutron-detection system constituting of liquid organic scintillators. The angular distributions of neutron yields and effective doses around the phantom were obtained by integrating the double-differential neutron yields and applying the fluence-to-effective dose conversion coefficients. The experimental data were compared with results of the Monte-Carlo simulation code PHITS. The PHITS results showed good agreement with the measured data. From the results, we concluded that the PHITS simulation is applicable to the dose estimation at carbon-therapy facilities.

Journal Articles

Accurate measurements of $$gamma$$-ray emission probabilities

Terada, Kazushi; Nakamura, Shoji; Kimura, Atsushi; Nakao, Taro; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; Hori, Junichi*

JAEA-Conf 2016-004, p.21 - 25, 2016/09

To obtain accurate cross section data, precise determination of the sample mass used in TOF measurements is essential, because uncertainties due to the sample mass are directly propagated to those of measured cross sections over the entire neutron energy region. Therefore, $$gamma$$-ray emission probabilities of $$^{241,243}$$Am, $$^{237,239}$$Np and $$^{233}$$Pa have been precisely measured with gamma- and alpha-ray spectroscopic methods. The activities of the samples were determined by measuring alpha particles using a Si semiconductor detector. $$gamma$$-rays emitted from the samples were measured with a planar type High-Purity Germanium (HPGe) detector. An efficiency curve of the Ge detector was derived by combining measured efficiencies and Monte Carlo simulation. The $$gamma$$-ray emission probabilities for the major $$gamma$$-rays of these nuclides were determined with uncertainties less than 2%.

Journal Articles

Molecular gyrotops with a five-membered heteroaromatic ring; Synthesis, temperature-dependent orientation of dipolar rotors inside the crystal, and its birefringence change

Masuda, Toshiyuki*; Arase, Junko*; Inagaki, Yusuke*; Kawahara, Masatoshi*; Yamaguchi, Kentaro*; Ohara, Takashi; Nakao, Akiko*; Momma, Hiroyuki*; Kwon, E.*; Setaka, Wataru*

Crystal Growth & Design, 16(8), p.4392 - 4401, 2016/08

 Times Cited Count:13 Percentile:9.6(Chemistry, Multidisciplinary)

Journal Articles

R&D of the heat measurement method for accurate determination of amount of minor actinides samples for accuracy improvement of neutron nuclear data

Nakao, Taro; Nakamura, Shoji; Terada, Kazushi; Kimura, Atsushi; Harada, Hideo; Igashira, Masayuki*; Katabuchi, Tatsuya*; Hori, Junichi*

JAEA-Conf 2015-003, p.303 - 306, 2016/03

In spite of that the precise information of the total amount of the measurement sample is required for the neutron capture cross-section determination, it is not always performed in sufficient accuracy. Therefore, it is necessary to determine the absolute amount of samples accurately with non-destructively. This presentation will report on the future plan about the heat deposit measurement from minor actinides samples in order to determine the absolute amount of samples non-destructively, especially about the radiation shielding which is a unique problem of RI sample case. Also report about the result of the benchmark test measurement using $$^{241}$$Am $$gamma$$-ray standard source. Present study includes the result of "Research and Development for accuracy improvement of neutron nuclear data on minor actinides" entrusted to the Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).

Journal Articles

Observation of all-in type tetrahedral displacements in nonmagnetic pyrochlore niobates

Torigoe, Shuhei*; Ishimoto, Yutaro*; Aoishi, Yuhei*; Murakawa, Hiroshi*; Matsumura, Daiju; Yoshii, Kenji; Yoneda, Yasuhiro; Nishihata, Yasuo; Kodama, Katsuaki; Tomiyasu, Keisuke*; et al.

Physical Review B, 93(8), p.085109_1 - 085109_5, 2016/02

 Times Cited Count:3 Percentile:66.42(Materials Science, Multidisciplinary)

Journal Articles

Accuracy improvement of neutron nuclear data on minor actinides

Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Mizuyama, Kazuhito; Igashira, Masayuki*; Katabuchi, Tatsuya*; et al.

EPJ Web of Conferences (Internet), 93, p.06001_1 - 06001_5, 2015/05

 Times Cited Count:3 Percentile:10.3

Improvement of accuracy of neutron nuclear data for minor actinides (MAs) and long-lived fission products (LLFPs) is required for developing innovative nuclear system transmuting these nuclei. In order to meet the requirement, the project entitled as "Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC)" has been started as one of the "Innovative Nuclear Research and Development Program" at October 2013. The AIMAC project team is composed of researchers in four different fields: differential nuclear data measurement, integral nuclear data measurement, nuclear chemistry, and nuclear data evaluation. By integrating all of the forefront knowledge and techniques in these fields, the team aims at improving the accuracy of the data. The background, overall plan, and recent progress of the AIMAC project will be reviewed.

Journal Articles

Emergent phenomena in perovskite-type manganites

Taguchi, Yasujiro*; Sakai, Hideaki*; Okuyama, Daisuke*; Ishiwata, Shintaro*; Fujioka, Jun*; Fukuda, Tatsuo; Hashizume, Daisuke*; Kagawa, Fumitaka*; Takahashi, Yoichiro*; Shimano, Ryo*; et al.

Physica B; Condensed Matter, 407(11), p.1685 - 1688, 2012/06

 Times Cited Count:3 Percentile:79.94(Physics, Condensed Matter)

Journal Articles

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

64 (Records 1-20 displayed on this page)