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-wave resonance of 
+
Okudaira, Takuya*; Nakabe, Rintaro*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Gudkov, V.*; Ide, Ikuo*; Ino, Takashi*; Ishikado, Motoyuki*; Kambara, Wataru*; et al.
Physical Review C, 109(4), p.044606_1 - 044606_9, 2024/04
-odd/
-odd interactions on the 0.75 eV -wave resonance in 
+
forward transmission determined using a pulsed neutron beamNakabe, Rintaro*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Gudkov, V.*; Hirota, Katsuya*; Ide, Ikuo*; Ino, Takashi*; Ishikado, Motoyuki*; Kambara, Wataru*; et al.
Physical Review C, 109(4), p.L041602_1 - L041602_4, 2024/04
rays from a neutron-induced -wave resonance of 
XeOkudaira, Takuya*; Tani, Yuika*; Endo, Shunsuke; Doskow, J.*; Fujioka, Hiroyuki*; Hirota, Katsuya*; Kameda, Kento*; Kimura, Atsushi; Kitaguchi, Masaaki*; Luxnat, M.*; et al.
Physical Review C, 107(5), p.054602_1 - 054602_7, 2023/05
Times Cited Count：2 Percentile：83.53(Physics, Nuclear)no abstracts in English
rays in the 
Sn(
)
Sn reactionEndo, Shunsuke; Okudaira, Takuya*; Abe, Ryota*; Fujioka, Hiroyuki*; Hirota, Katsuya*; Kimura, Atsushi; Kitaguchi, Masaaki*; Oku, Takayuki; Sakai, Kenji; Shima, Tatsushi*; et al.
Physical Review C, 106(6), p.064601_1 - 064601_7, 2022/12
Times Cited Count：3 Percentile：49.92(Physics, Nuclear)no abstracts in English
rays from the -wave resonance of SnKoga, Jun*; Takada, Shusuke*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Niinomi, Yudai*; Okudaira, Takuya*; et al.
Physical Review C, 105(5), p.054615_1 - 054615_5, 2022/05
Times Cited Count：4 Percentile：64.25(Physics, Nuclear)no abstracts in English
through water-soluble Ti complexes as raw material for controlling particle size and distribution of synthesized BaTiO
nanocubesNakashima, Koichi*; Hironaka, Kota*; Ouchi, Kazuma*; Ajioka, Mao*; Kobayashi, Yoshio*; Yoneda, Yasuhiro; Yin, S.*; Kakihana, Masato*; Sekino, Toru*
ACS Omega (Internet), 6(48), p.32517 - 32527, 2021/12
Times Cited Count：5 Percentile：36.83(Chemistry, Multidisciplinary)The BaTiO nanoparticles synthesized by the hydrothermal method is examined by synchrotron X-ray and TEM observation. It was found that the particle size of synthesized BaTiO depends on the particle size of the raw material of TiO. Succeeded in synthesizing 100 nm size BaTiO nanocrystals showing uniform particle size distribution using TiO nanoparticles with optimized particle size. The obtained BaTiO nanocrystal is a tetragonal system of ferroelectric phase. A three-dimensional structure of BaTiO nanoparticles could be obtained by the electron beam tomography.
Nishimura, Shoichiro*; Torii, Hiroyuki*; Fukao, Yoshinori*; Ito, Takashi; Iwasaki, Masahiko*; Kanda, Sotaro*; Kawagoe, Kiyotomo*; Kawall, D.*; Kawamura, Naritoshi*; Kurosawa, Noriyuki*; et al.
Physical Review A, 104(2), p.L020801_1 - L020801_6, 2021/08
Times Cited Count：13 Percentile：84.11(Optics) rays in the La(
)
La
reactionOkudaira, Takuya*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Niinomi, Yudai*; Sakai, Kenji; et al.
Physical Review C, 104(1), p.014601_1 - 014601_6, 2021/07
Times Cited Count：4 Percentile：55.56(Physics, Nuclear)Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：44 Percentile：97.1(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
O
Yoshioka, Satoru*; Tsuruta, Konosuke*; Yamamoto, Tomokazu*; Yasuda, Kazuhiro*; Matsumura, Sho*; Sugiyama, Takeharu*; Oba, Yojiro; Ishikawa, Norito; Kobayashi, Eiichi*; Okudaira, Koji*
Journal of the American Ceramic Society, 103(8), p.4654 - 4663, 2020/08
Times Cited Count：4 Percentile：22.32(Materials Science, Ceramics)X-ray absorption near edge structure (XANES) and small-angle X-ray scattering (SAXS) reveal the damaged structures in MgAlO spinel induced by swift heavy ions. SAXS indicates the formation of ion tracks with cylindrical shape with a diameter of 5 nm. XANES indicates the cationic disordering between tetrahedral and octahedral sites by the irradiation. Quantitative analysis of XANES also reveals that cations preferably occupy the octahedral sites at high fluence.
rays from neutron-induced compound states of LaYamamoto, Tomoki*; Okudaira, Takuya; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ino, Takashi*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; et al.
Physical Review C, 101(6), p.064624_1 - 064624_8, 2020/06
Times Cited Count：9 Percentile：72.89(Physics, Nuclear)-rays after neutron capture by La for a T-violation searchOkudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.
EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12
Parity violating effects enhanced by up to 10
times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,) reaction was measured with La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized La target and a 70% polarized 
He spin filter whose thickness is 70 atm
cm are needed. Therefore high quality He spin filter is developed in JAEA. The measurement result of the (n,) reaction at J-PARC and the development status of the He spin filter will be presented.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Arai, Takehiko*; Nakauchi, Yusuke*; Nakamura, Tomoki*; Matsuoka, Moe*; et al.
Science, 364(6437), p.272 - 275, 2019/04
Times Cited Count：262 Percentile：99.73(Multidisciplinary Sciences)The near-Earth asteroid 162173 Ryugu, the target of Hayabusa2 sample return mission, is believed to be a primitive carbonaceous object. The Near Infrared Spectrometer (NIRS3) on Hayabusa2 acquired reflectance spectra of Ryugu's surface to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micron was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally- and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.
Shimomura, Yusuke; Sato, Takuya; Fukui, Yasutaka; Kudo, Kenji; Yoshioka, Tatsuji
JAEA-Review 2018-023, 220 Pages, 2019/01
JAEA-Review-2018-023.pdf:15.6MB
On September 11, 2015, leaky traces of bituminized wastes were confirmed from four drums filled with bituminization in waste packages storage yard (II) of waste management facility in Oarai Research and Development Center. Moreover, even after the subsequent investigation, a leakage trace was found from one bituminous drum on November 10, 2015. Furthermore, on December 2, 2015, there was no a leakage trace in one bituminous drum, however the upper lid was found to be intensely corroded. To investigate the causes and the countermeasures for leakages of bituminized wastes from the drums, we have set up a Work Group to investigate the causes and the countermeasures to leakage traces from the drums. This report is based on "Report on Cause Investigation and Countermeasure of Leakage Trace from the Drum" summarized by this working group, the report was reconstructed including the contents clarified in the subsequent document investigation.
Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
Times Cited Count：13 Percentile：98.93(Quantum Science & Technology)Ichikawa, Kenta*; Kanda, Hironori; Yoshioka, Naoki*; Ara, Kuniaki; Saito, Junichi; Nagai, Keiichi
Proceedings of 26th International Conference on Nuclear Engineering (ICONE-26) (Internet), 6 Pages, 2018/07
Studies on the suppression of the reactivity of sodium itself have been performed on the basis of the concept of suspended nanoparticles in liquid sodium (sodium nanofluid). According to the experimental and theoretical results of studies for sodium nanofluid, velocity and heat of sodium nanofluid-water reaction are lower than those of the pure sodium-water reaction. The analytical model for the peak temperature of a sodium nanofluid-water reaction jet has been developed in consideration of these suppression effects by the authors. In this paper, the prediction method for mitigation effects for a damage of adjacent tubes in a steam generator tube rupture (SGTR) accidents is arranged by applying this analytical model for the peak temperature of the reaction jet. On the assumption that the sodium nanofluid is used for the secondary coolant of sodium-cooled fast reactor (SFR), mitigation effects under the design-base accident (DBA) condition and the design-extension condition (DEC) of SGTR are estimated by using this method. As a result, there is a possibility to reduce the number of damaged tubes and to suppress the pressure generated by SGTR accidents by using sodium nanofluid in the secondary coolant.
rays from neutron-induced compound states of LaOkudaira, 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
Times Cited Count：13 Percentile：70.79(Physics, Nuclear)-rays at the ANNRI in the MLF of the J-PARCTakada, 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
Times Cited Count：6 Percentile：30.66(Instruments & Instrumentation)O induced by swift heavy ionsYoshioka, Satoru*; Tsuruta, Konosuke*; Yamamoto, Tomokazu*; Yasuda, Kazuhiro*; Matsumura, Sho*; Ishikawa, Norito; Kobayashi, Eiichi*
Physical Chemistry Chemical Physics, 20(7), p.4962 - 4969, 2018/02
Times Cited Count：5 Percentile：22.84(Chemistry, Physical)Cationic disorder in the MgAlO spinel induced by swift heavy ions was investigated using the X-ray absorption near edge structure. With changes in the irradiation fluences of 200 MeV Xe ions, the Mg K-edge and Al K-edge spectra were synchronously changed. The calculated spectra based on density function theory indicate that the change in the experimental spectra was due to cationic disorder between Mg in tetrahedral sites and Al in octahedral sites. These results suggest a high inversion degree to an extent that the completely random configuration is achieved in MgAlO induced by the high density electronic excitation under swift heavy ion irradiation.
B conversion layerMiyajima, Shigeyuki*; Shishido, Hiroaki*; Narukami, Yoshito*; Yoshioka, Naohito*; Fujimaki, Akira*; Hidaka, Mutsuo*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Arai, Masatoshi*; et al.
Nuclear Instruments and Methods in Physics Research A, 842, p.71 - 75, 2017/01
Times Cited Count：13 Percentile：77.73(Instruments & Instrumentation)