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Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：6 Percentile：51.19(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nomura, Kazunori; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Hagura, Naoto*; Kubota, Toshio*
Nuclear Instruments and Methods in Physics Research B, 477, p.54 - 59, 2020/08
Times Cited Count：5 Percentile：45.45(Instruments & Instrumentation)
F from 
O
?Tang, T. L.*; Uesaka, Tomohiro*; Kawase, Shoichiro; Beaumel, D.*; Dozono, Masanori*; Fujii, Toshihiko*; Fukuda, Naoki*; Fukunaga, Taku*; Galindo-Uribarri, A.*; Hwang, S. H.*; et al.
Physical Review Letters, 124(21), p.212502_1 - 212502_6, 2020/05
Times Cited Count：14 Percentile：74.18(Physics, Multidisciplinary)The structure of a neutron-rich F nucleus is investigated by a quasifree (
) knockout reaction. The sum of spectroscopic factors of 
orbital is found to be 1.0 
0.3. The result shows that the O core of F nucleus significantly differs from a free O nucleus, and the core consists of 
35% O
, and 65% excited O. The result shows that the O core of F nucleus significantly differs from a free O nucleus. The result may infer that the addition of the 
proton considerably changes the neutron structure in F from that in O, which could be a possible mechanism responsible for the oxygen dripline anomaly.
Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nakamura, Masahiro; Shibata, Atsuhiro; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Hagura, Naoto*; et al.
International Journal of PIXE, 29(1&2), p.17 - 31, 2019/00
The spent PUREX solvent containing U and Pu is generated from the reprocessing process of spent nuclear fuel. The nuclear material removal is important for the safe storage or disposal of the spent solvent. Our previous study revealed that the adsorbent with the iminodiacetic acid (IDA) functional group is one of the most promising materials for designing the nuclear material recovery process. Accordingly, an IDA-type adsorbent was synthesized by using graft polymerization technology or a chemical reaction to improve the adsorption rate and capacity. The synthesized IDA-type adsorbent was characterized by micro particle-induced X-ray emission (PIXE) and extended X-ray absorption fine structure (EXAFS) analyses. The micro-PIXE analysis revealed that Zr was adsorbed on the whole synthesized adsorbents and quantified the microamount of adsorbed Zr. Moreover, EXAFS suggested that Zr in the aqueous solution and solvent can be trapped by the IDA group with different mechanisms.
Yagi, Naoto*; Matsuo, Tatsuhito; Ota, Noboru*
Journal of Synchrotron Radiation, 19(4), p.574 - 578, 2012/07
Times Cited Count：1 Percentile：7.11(Instruments & Instrumentation)X-ray diffraction patterns were recorded from isolated single rod outer segments of frog. The outer segments in Ringer's solution were exposed to a 6 
m microbeam (15 keV) at the BL40XU beamline, SPring-8. The diffraction pattern demonstrated a remarkable regularity in the stacking and flatness of the disk membranes. The electron density profile calculated from the intensity of up to tenth-order reflections showed a pair of bilayers that comprise a disk membrane. The structure of the disk membrane and the changes in the profile on swelling generally agreed with previous reports. Radiation damage was significant with an irradiation of 5 
10
Gy which is much lower than the known damaging dose on proteins at the liquid-nitrogen temperature.
Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Yokota, Wataru; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 173, 2012/01
Three electrostatic accelerators of TIARA were operated smoothly in FY 2010, and all the planned experiments were carried out except those canceled by users or the impact of Great East Japan Earthquake on March 11, 2011. On the other hand, Saturday operation for experiments was carried out after October on the Global Nuclear-Human Resource Development Initiative. The yearly operation time of the tandem accelerator, the single-ended accelerator and the ion implanter amounted to 2116, 2367 and 1800 hours, respectively, which were similar to those of usual years. Regarding the single-ended accelerator, the generator in the high-voltage terminal failed and was replaced with new one. A switching magnet was installed for a new branch beam line of the ion implanter. As to the tandem accelerator, In ion was generated and accelerated at intensity of 500 nA.
Yamaguchi, Daisuke; Miyamoto, Nobuyoshi*; Fujita, Takako*; Nakato, Teruyuki*; Koizumi, Satoshi; Ota, Noboru*; Yagi, Naoto*; Hashimoto, Takeji
Physical Review E, 85(1), p.011403_1 - 011403_15, 2012/01
Times Cited Count：21 Percentile：75.06(Physics, Fluids & Plasmas)Phase transition of aqueous colloidal dispersions of charged plate-like particles of niobate nanosheets were investigated as a function of the aspect ratio (
) and particle volume concentration (
) by small-angle neutron scattering and small-angle X-ray scattering. The results elucidated the following three pieces of evidence: (1) the macroscopic phase separation of the dispersions into an isotropic phase and a liquid crystalline phase (LC) under the condition of (a) varying at a constant = 0.01, and of (b) varying (0.01 
0.025) at a constant = 2.510
. (2) the -induced phase transition of the LC phase from a nematic phase to a highly periodic layered phase upon increasing r under the condition (a). (3) the LC phase having remarkable concentration fluctuations of the particles which are totally unexpected for the conventional lyotropic molecular LC but which are anticipated to be general for the plate-like colloidal particles.
C targets on Au backingsSugai, Isao*; Takeda, Yasuhiro*; Kawakami, Hirokane*; Ota, Naoto*; Makii, Hiroyuki; Miyatake, Hiroari*
Nuclear Instruments and Methods in Physics Research A, 655(1), p.24 - 33, 2011/11
Times Cited Count：3 Percentile：26.67(Instruments & Instrumentation)
and CePtSiHirose, Yusuke*; Nishimura, Naoto*; Honda, Fuminori*; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; Kindo, Koichi*; Takeuchi, Tetsuya*; Yamamoto, Etsuji; Haga, Yoshinori; Matsuura, Masato*; et al.
Journal of the Physical Society of Japan, 80(2), p.024711_1 - 024711_12, 2011/02
Times Cited Count：7 Percentile：47.32(Physics, Multidisciplinary)Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Yokota, Wataru; et al.
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 181, 2011/01
Three electrostatic accelerators of TIARA were operated smoothly in FY 2009, and all the planned experiments were carried out except those canceled by users. The yearly operation time of the tandem accelerator, the single-ended accelerator and the ion implanter amounted to 2100, 2416 and 1866 hours, respectively. Regarding the single-ended accelerator, the radio frequency oscillator of the ion source mounted in high-voltage terminal and the sequencer for control of the SB beam line failed, and they were replaced. The oven controller of Freeman ion source of the ion implanter was renewed. As to the tandem accelerator, Mn ion was successfully generated and accelerated with intensity of 150 nA.
Chiba, Atsuya; Uno, Sadanori; Yamada, Keisuke; Yokoyama, Akihito; Agematsu, Takashi; Yokota, Wataru; Kitano, Toshihiko*; Takayama, Terumitsu*; Kanai, Shinji*; Orimo, Takao*; et al.
Dai-23-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.119 - 122, 2010/11
Operation times of each accelerator are keeping the same level as in recent 10 years, Tandem accelerator, Single-ended and Ion implanter amounted to about 2,000, 2,500 and 1,900 hours, respectively. In the last fiscal year, we succeeded in maintaining the terminal voltage of the tandem accelerator to high stability for long periods by exchanging the material of a corona-probe needle to the tungsten (NPS Co.). In the ion-implanter, the oven control system equipped with the Freeman ion source was renewed. There was no trouble to affect on the machine-time in the last fiscal year, so the all planned experiments were carried out.
Tokiwa, Tetsuya; Asamori, Koichi; Hiraga, Naoto*; Yamada, Osamu; Moriya, Hirokazu*; Hotta, Hikaru*; Kitamura, Itaru*; Yokota, Hideharu
Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.117 - 122, 2010/10
In this paper, we discuss the relationship between the accurate hypocentral distribution and 3-D geological structure in and around the Horonobe area, Japan. We carried out multiplet-clustering analysis by using data of the 421 micro-earthquakes which occurred from 1st September, 2003 to 30th September, 2007. The 3-D geological structure model was mainly constructed from previous seismic reflection profiles and drilling data. As a result of this analysis, although there are some differences in depth between them, the hypocenters are distributed in NNW-SSE direction and become deeper from the west toward the east. The distributed pattern of the hypocenters is similar to the one of the geological structure. These results indicate that the hypocentral distribution may represent existence of active zone related to the geological structure, and provide effective information which can contribute to establishing methods for estimating the future evolution of the geological environment.
Yamamura, Tsukasa; Matsushima, Hideya; Otsuka, Naoto*; Tazaki, Makiko; Mizuma, Hideki*; Kadota, Koshu*; Kimoto, Toru
JAEA-Review 2010-040, 180 Pages, 2010/09
JAEA-Review-2010-040.pdf:4.84MB
Japan initiated a program of peaceful use of nuclear energy in 1950s. Since that time, Japan has made it clear that the program is carried out strictly for peaceful purposes in a transparent manner, implementing measures to win trust from international community. In this report, we review, analyze and evaluate Japan's efforts to ensure nuclear non-proliferation, deviding them into seven categories. Through such review, analysis and evaluation, the significant elements in terms of wining the trust for the peaceful nature of the nuclear energy use and future challenges have been identified for each category stated above. We expect this report to contribute to the discussion on the policy of peaceful use of nuclear energy and nuclear non-proliferation within the Atomic Energy Commission of Japan and to be any use for the states which plan to initiate nuclear energy use program on a significant scale including the deployment of nuclear power plants.
, CeCd, and PrCd with a caged crystal structureYoshiuchi, Shingo*; Takeuchi, Tetsuya*; Oya, Masahiro*; Katayama, Keisuke*; Matsushita, Masaki*; Yoshitani, Naohisa*; Nishimura, Naoto*; Ota, Hisashi*; Tateiwa, Naoyuki; Yamamoto, Etsuji; et al.
Journal of the Physical Society of Japan, 79(4), p.044601_1 - 044601_11, 2010/04
Times Cited Count：12 Percentile：59.61(Physics, Multidisciplinary)Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Yokota, Wataru; et al.
JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 175, 2009/12
Three electrostatic accelerators of TIARA were operated smoothly in FY 2008, and all the planned experiments were carried out except those canceled by users. The yearly operation time of the tandem accelerator, the single-ended accelerator and the ion implanter amounted to 2009, 2426 and 1882 hours, respectively. Regarding the tandem accelerator, the control system was renewed, and the unstable acceleration voltage caused by mechanical vibration reduced by adjusting the driving mechanism of the pellet chains. The SF
gas for the single-ended accelerator was purified, and its storage tank was repainted. As to the ion implanter, Bi
ion, which was requested by users, was successfully generated and accelerated with intensity of 0.5A.
Osawa, Hideaki; Ota, Kunio; Hama, Katsuhiro; Sawada, Atsushi; Takeuchi, Shinji; Amano, Kenji; Saegusa, Hiromitsu; Matsuoka, Toshiyuki; Miyamoto, Tetsuo; Toyoda, Gakuji; et al.
JAEA-Research 2008-085, 742 Pages, 2008/11
JAEA-Research-2008-085-1.pdf:26.22MBJAEA-Research-2008-085-2.pdf:16.64MBJAEA-Research-2008-085-3.pdf:28.27MB
This report shows the results the project for the establishment of comprehensive site characterization technology, entrusted from Natural Resources and Energy Agency, Ministry of Economy, Trade and Industry Natural Resources and Energy Agency in 2007.
Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Mizuhashi, Kiyoshi; et al.
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 191, 2008/11
Three electrostatic accelerators were operated smoothly in FY 2007, and all the planned experiments were carried out except those canceled by users. The yearly operation time of the tandem accelerator, the single-ended accelerator and the ion implanter amounted to 1949, 2437 and 1900 hours. The high-pressure residual gas of SF is leaking from the SF gas handling system of the tandem accelerator. The most amount of the leak comes out when the accelerator tank pressure is high. Therefore, in order to reduce the leak by lowering the residual gas pressure, a pipe was installed to carry the gas in the high-pressure part of the system for the accelerator to the low-pressure storage tank. As to the ion implanter, Pb ion, which was requested by users, was successfully generated using oven method and accelerated with intensity of 1.5 A.
Ga
(=Ni, Pd, and Pt)Kuzushita, Kaori*; Ishii, Kenji; Wilkins, S. B.*; Janousova, B.*; Inami, Toshiya; Owada, Kenji; Tsubota, Masami; Murakami, Yoichi; Kaneko, Koji; Metoki, Naoto; et al.
Physical Review B, 73(10), p.104431_1 - 104431_5, 2006/03
Times Cited Count：8 Percentile：38.44(Materials Science, Multidisciplinary)We report a resonant X-ray scattering study of antiferromagnetic uranium compounds UGa (=Ni, Pd, and Pt) at the Ga 
-edge. A large resonant signal is observed below the N
el temperatures. The azimuth dependence in both 
-
and -
polarization channels establishes that the resonant signal has the symmetry of the magnetic dipole. This resonance with the band electrons is interpreted within a semi-localized model as an orbital polarization of the Ga 
states induced through strong hybridization with U 
valence level. These results demonstrate that resonant magnetic X-ray scattering at the anions, taken in combination with symmetry arguments, can be used to determine the configuration of the U moments and provide information about the hybridization.
Kawasaki, Hirotsugu; Yasumatsu, Naoto*; Kubota, Sadae*; Shiotani, Hiroki; Ono, Kiyoshi
JAEA-Research 2006-001, 60 Pages, 2006/02
JAEA-Research-2006-001.pdf:4.37MB
no abstracts in English
Inoue, Naoko; Hori, Keiichiro; Dosho, Hisaharu; Ota, Kiyokazu*; Otsuka, Naoto; Aso, Ryoji; Senzaki, Masao
Proceedings of INMM 47th Annual Meeting (CD-ROM), 6 Pages, 2006/00
no abstracts in English
