Organization
Graduate School of Science Assistant Professor
Graduate School
Graduate School of Science
Undergraduate School
School of Science Department of Physics
Title
Assistant Professor
External link
OKUDAIRA Takuya
Research Areas
Research Areas 2
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Natural Science / Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics / Fundamental neutron physics
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Energy Engineering / Quantum beam science / Neutron Optics, Neutron Polarization device
Research History
Research History 3
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Japan Atomic Energy Agency J-PARC Center Visiting researcher
2021.4
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Nagoya University Assistant Professor
2021.1
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Japan Atomic Energy Agency J-PARC Center/ Postdoctoral fellow
2018.4 - 2020.12
Professional Memberships
Professional Memberships 2
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日本物理学会
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THE JAPANESE SOCIETY FOR NEUTRON SCIENCE
Committee Memberships
Committee Memberships 2
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中性子科学会 広報幹事
2024.4
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Committee type：Academic society
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中性子科学会 中性子科学会誌 波紋 編集委員会
2019.4 - 2023.3
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Committee type：Academic society
Awards
Awards 3
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奨励賞
2021.12 中性子科学会
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波紋 President Choice 賞
2020.11 中性子科学会
奥平琢也
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学生奨励賞
2017.2 2016年度量子ビームサイエンスフェスタ 複合核における時間反転対称性の破れ探索実験
奥平琢也
Papers
Papers 65
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Kazuyoshi Tatsumi, Takuya Okudaira, Maiko Kofu, Piotr Rozyczko
Journal of Physics: Condensed Matter Vol. 36 ( 37 ) page： 375901 - 375901 2024.9
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Language：English Publishing type：Research paper (scientific journal) Publisher：IOP Publishing
Abstract
This study re-evaluates the theoretical approach to analyzing inelastic neutron spectra of hydrogen-containing metals and intermetallic compounds. Previously, these analyses utilized hydrogen quantum nuclear states, modeled as solutions to the Schrödinger equation. The potential surfaces in these models were approximated from the total energies derived from first-principles electronic structure calculations. The current study improves upon this method by employing more efficient and accurate treatments for sampling the potential surface. It utilizes symmetrically irreducible sampling points arranged on densely populated mesh grids for the first-principles calculations. A comparative analysis of the theoretical predictions with experimental spectra for hydrides of Ti<sub>2</sub>Sb and Ti<sub>3</sub>Sb, as well as a LaNi<sub>5</sub> hydrogen primary solid solution, demonstrates that this approach is promising for elucidating the unknown local environments of hydrogen atoms in systems where the approximate potential well describes the hydrogen quantum states.Other Link： https://iopscience.iop.org/article/10.1088/1361-648X/ad559b/pdf
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R. Nakabe, C. J. Auton, S. Endo, H. Fujioka, V. Gudkov, K. Hirota, I. Ide, T. Ino, M. Ishikado, W. Kambara, S. Kawamura, A. Kimura, M. Kitaguchi, R. Kobayashi, T. Okamura, T. Oku, T. Okudaira, M. Okuizumi, J. G. Otero Munoz, J. D. Parker, K. Sakai, T. Shima, H. M. Shimizu, T. Shinohara, W. M. Snow, S. Takada, R. Takahashi, S. Takahashi, Y. Tsuchikawa, T. Yoshioka
Physical Review C Vol. 109 ( 4 ) 2024.4
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Publishing type：Research paper (scientific journal)
Neutron transmission experiments can offer a new type of highly sensitive search for time-reversal invariance violating (TRIV) effects in nucleon-nucleon interactions via the same enhancement mechanism observed for large parity violating (PV) effects in neutron-induced compound nuclear processes. In these compound processes, the TRIV cross section is given as the product of the PV cross section, a spin factor κ, and a ratio of TRIV and PV matrix elements. We determined κ to be 0.59±0.05 for La139+n using both (n,γ) spectroscopy and (n→ +139La→) transmission. This result quantifies for the first time the high sensitivity of the La139 0.75-eV p-wave resonance in a future search for effects of P-odd/T-odd interactions in (n→ +139La→) forward transmission.
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Spin dependence in the p -wave resonance of 139 La + n Reviewed
T. Okudaira, R. Nakabe, C. J. Auton, S. Endo, H. Fujioka, V. Gudkov, I. Ide, T. Ino, M. Ishikado, W. Kambara, S. Kawamura, R. Kobayashi, M. Kitaguchi, T. Okamura, T. Oku, J. G. Otero Munoz, J. D. Parker, K. Sakai, T. Shima, H. M. Shimizu, T. Shinohara, W. M. Snow, S. Takada, Y. Tsuchikawa, R. Takahashi, S. Takahashi, H. Yoshikawa, T. Yoshioka
Physical Review C Vol. 109 ( 4 ) 2024.4
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Authorship：Lead author Publishing type：Research paper (scientific journal)
We measured the spin-dependent cross section at a neutron-induced p-wave resonance using a polarized epithermal neutron beam and a polarized nuclear target. Our study focuses on the 0.75 eV p-wave resonance of La139+n, where previous experiments have shown a large enhancement of parity violation. The spin dependence of the neutron absorption cross section of polarized La139 and polarized neutrons determines the partial neutron width of the p-wave resonance. This partial width is a key parameter needed to determine the sensitivity of this system to possible parity-odd and time reversal-odd interactions beyond the standard model. Our findings therefore serve as a foundation for a future search for time reversal violation in this compound nuclear system.
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Angular distribution of γ-rays from a neutron-induced p-wave resonance of 132Xe Reviewed Open Access
T. Okudaira, Y. Tani, S. Endo, J. Doskow, H. Fujioka, K. Hirota, K. Kameda, A. Kimura, M. Kitaguchi, M. Luxnat, K. Sakai, D. C. Schaper, T. Shima, H. M. Shimizu, W. M. Snow, S. Takada, T. Yamamoto, H. Yoshikawa, T. Yoshioka
Physical Review C Vol. 107 ( 5 ) 2023.5
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Authorship：Lead author Publishing type：Research paper (scientific journal) Publisher：American Physical Society (APS)
DOI： 10.1103/PhysRevC.107.054602
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevC.107.054602/fulltext
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Measurement of the transverse asymmetry of γ rays in the 117Sn(n,γ)118Sn reaction Reviewed Open Access
S. Endo, T. Okudaira, R. Abe, H. Fujioka, K. Hirota, A. Kimura, M. Kitaguchi, T. Oku, K. Sakai, T. Shima, H. M. Shimizu, S. Takada, S. Takahashi, T. Yamamoto, H. Yoshikawa, T. Yoshioka
Physical Review C Vol. 106 ( 6 ) 2022.12
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Language：English Publishing type：Research paper (scientific journal) Publisher：American Physical Society (APS)
Largely enhanced parity-violating effects observed in compound resonances induced by epithermal neutrons are currently attributed to the mixing of parity-unfavored partial amplitudes in the entrance channel of the compound states. Furthermore, it is proposed that the same mechanism that enhances the parity violation also enhances the breaking of time-reversal invariance in the compound nucleus. The entrance-channel mixing induces energy-dependent spin-angular correlations of individual γ rays emitted from the compound nuclear state. For a detailed study of the mixing model, the γ-ray yield in the reaction of Sn117(n,γ)Sn118 was measured using a pulsed beam of polarized epithermal neutrons and Ge detectors. An angular dependence of asymmetric γ-ray yields for the orientation of the neutron polarization was observed.
DOI： 10.1103/PhysRevC.106.064601
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevC.106.064601/fulltext
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Energy-dependent angular distribution of individual gamma rays in the La-139(n, gamma) La-140* reaction Reviewed Open Access
T. Okudaira, S. Endo, H. Fujioka, K. Hirota, K. Ishizaki, A. Kimura, M. Kitaguchi, J. Koga, Y. Niinomi, K. Sakai, T. Shima, H. M. Shimizu, S. Takada, Y. Tani, T. Yamamoto, H. Yoshikawa, T. Yoshioka
PHYSICAL REVIEW C Vol. 104 ( 1 ) 2021.7
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Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：AMER PHYSICAL SOC
Neutron energy-dependent angular distributions were observed for individual gamma rays from the 0.74 eV p-wave resonance of La-139+n to several lower excited states of La-140. The gamma-ray signals were analyzed in a two-dimensional histogram of the gamma-ray energy, measured with distributed germanium detectors, and neutron energy, determined with the time-of-flight of pulsed neutrons, to identify the neutron energy dependence of the angular distribution for each individual gamma rays. The angular distribution was also found for a photopeak accompanied with a faint p-wave resonance component. Our results can be interpreted as interference between s- and p-wave amplitudes, which may be used to study discrete symmetries of fundamental interactions.
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Polarization analysis for small-angle neutron scattering with a 3He spin filter at a pulsed neutron source Reviewed
T. Okudaira, Y. Ueda, K. Hiroi, R. Motokawa,* Y. Inamura, S. Takata, T. Oku, J. Suzuki, S. Takahashi, H. Endo, H. Iwase
Vol. 54 ( 2 ) page： 548 - 556 2021.4
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Authorship：Lead author, Corresponding author Language：English Publishing type：Research paper (scientific journal)
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Takuya Okudaira, Yuki Ueda, Kosuke Hiroi, Ryuhei Motokawa, Yasuhiro Inamura, Shin-ichi Takata, Takayuki Oku, Jun-ichi Suzuki, Shingo Takahashi, Hitoshi Endo, Hiroki Iwase
Journal of Applied Crystallography Vol. 54 ( 2 ) page： 548 - 556 2021.4
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Authorship：Lead author Publishing type：Research paper (scientific journal) Publisher：International Union of Crystallography (IUCr)
Neutron polarization analysis (NPA) for small-angle neutron scattering (SANS) experiments using a pulsed neutron source was successfully achieved by applying a <sup>3</sup>He spin filter as a spin analyzer for the neutrons scattered from the sample. The cell of the <sup>3</sup>He spin filter gives a weak small-angle scattering intensity (background) and covers a sufficient solid angle for performing SANS experiments. The relaxation time of the <sup>3</sup>He polarization is sufficient for continuous use for approximately 2 days, thus reaching the typical duration required for a complete set of SANS experiments. Although accurate evaluation of the incoherent neutron scattering, which is predominantly attributable to the extremely large incoherent scattering cross section of hydrogen atoms in samples, is difficult using calculations based on the sample elemental composition, the developed NPA approach with consideration of the influence of multiple neutron scattering enabled reliable decomposition of the SANS intensity distribution into the coherent and incoherent scattering components. To date, NPA has not been well established as a standard technique for SANS experiments at pulsed neutron sources such as the Japan Proton Accelerator Research Complex (J-PARC) and the US Spallation Neutron Source. It is anticipated that this work will contribute significantly to the accurate determination of the coherent neutron scattering component for scatterers in various types of organic sample systems in SANS experiments at J-PARC, particularly for systems involving competition between the coherent and incoherent scattering intensity.
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Development and application of a 3He Neutron Spin Filter at J-PARC Reviewed Open Access
T. Okudaira, T. Oku, T. Ino, H. Hayashida, H. Kira, K. Sakai, K. Hiroi, S. Takahashi, K. Aizawa, H. Endo, S. Endo, M. Hino, K. Hirota, T. Honda, K. Ikeda, K. Kakurai, W. Kambara, M. Kitaguchi, T. Oda, H. Ohshita, T. Otomo, H.M. Shimizu, T. Shinohara, J. Suzuki, T. Yamamoto
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Vol. 977 page： 164301 - 164301 2020.10
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Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier BV
We are developing a neutron polarizer with polarized He-3 gas, referred to as a He-3 spin filter, based on the Spin Exchange Optical Pumping (SEOP) for polarized neutron scattering experiments at Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). A He-3 gas-filling station was constructed at J-PARC, and several He-3 cells with long spin relaxation times have been fabricated using the gas-filling station. A laboratory has been prepared in the MLF beam hall for polarizing He-3 cells, and compact pumping systems with laser powers of 30 W and 110 W, which can be installed onto a neutron beamline, have been developed. A He-3 polarization of 85% was achieved at a neutron beamline by using the pumping system with the 110 W laser. Recently, the first user experiment utilizing the He-3 spin filter was conducted, and there have been several more since then. The development and utilization of He-3 spin filters at MLF of J-PARC are reported.
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Transverse asymmetry of γ rays from neutron-induced compound states of La140 Reviewed Open Access
T. Yamamoto, T. Okudaira, S. Endo, H. Fujioka, K. Hirota, T. Ino, K. Ishizaki, A. Kimura, M. Kitaguchi, J. Koga, S. Makise, Y. Niinomi, T. Oku, K. Sakai, T. Shima, H. M. Shimizu, S. Takada, Y. Tani, H. Yoshikawa, T. Yoshioka
Physical Review C Vol. 101 ( 6 ) 2020.6
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Publishing type：Research paper (scientific journal) Publisher：American Physical Society (APS)
DOI： 10.1103/PhysRevC.101.064624
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevC.101.064624/fulltext
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Angular distribution of γ rays from neutron-induced compound states of la 140 Reviewed Open Access
T. Okudaira, S. Takada, K. Hirota, A. Kimura, M. Kitaguchi, J. Koga, K. Nagamoto, T. Nakao, A. Okada, K. Sakai, H. M. Shimizu, T. Yamamoto, T. Yoshioka
Physical Review C Vol. 97 ( 3 ) 2018.3
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Authorship：Lead author Publishing type：Research paper (scientific journal)
© 2018 American Physical Society. The angular distribution of individual γ rays, emitted from a neutron-induced compound-nuclear state via radiative capture reaction of La139(n,γ) has been studied as a function of incident neutron energy in the epithermal region by using germanium detectors. An asymmetry ALH was defined as (NL-NH)/(NL+NH), where NL and NH are integrals of low- and high-energy region of a neutron resonance respectively, and we found that ALH has the angular dependence of (Acosθγ+B), where θγ is the emitted angle of γ rays, with A=-0.3881±0.0236 and B=-0.0747±0.0105 in 0.74 eV p-wave resonance. This angular distribution was analyzed within the framework of interference between s- and p-wave amplitudes in the entrance channel to the compound-nuclear state, and it is interpreted as the value of the partial p-wave neutron width corresponding to the total angular momentum of the incident neutron combined with the weak matrix element, in the context of the mechanism of enhanced parity-violating effects. Additionally, we use the result to quantify the possible enhancement of the breaking of time-reversal invariance in the vicinity of the p-wave resonance.
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Transverse asymmetry of individual $\ensuremath{\gamma}$ rays in the $^{139}\mathrm{La}(\stackrel{P\vec}{n},\phantom{\rule{0.16em}{0ex}}\ensuremath{\gamma})^{140}\mathrm{La}$ reaction Reviewed
Okuizumi, M. and Auton, C. J. and Endo, S. and Fujioka, H. and Hirota, K. and Ino, T. and Ishizaki, K. and Kimura, A. and Kitaguchi, M. and Koga, J. and Makise, S. and Niinomi, Y. and Oku, T. and Okudaira, T. and Sakai, K. and Shima, T. and Shimizu, H. M. and Tada, H. and Takada, S. and Takahashi, S. and Tani, Y. and Yamamoto, T. and Yoshikawa, H. and Yoshioka, T.
Physical Review C Vol. 111 ( 034611 ) 2025.3
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Language：English Publishing type：Research paper (scientific journal)
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Performance of the Fully Equipped Spin Flip Chopper for the Neutron Lifetime Experiment at J-PARC Reviewed Open Access
K Mishima, G Ichikawa, Y Fuwa, T Hasegawa, M Hino, R Hosokawa, T Ino, Y Iwashita, M Kitaguchi, S Matsuzaki, T Mogi, H Okabe, T Oku, T Okudaira, Y Seki, H E Shimizu, H M Shimizu, S Takahashi, M Tanida, S Yamashita, M Yokohashi, T Yoshioka
Progress of Theoretical and Experimental Physics Vol. 2024 ( 9 ) 2024.9
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Publishing type：Research paper (scientific journal) Publisher：Oxford University Press (OUP)
Abstract
To solve the “neutron lifetime puzzle,” where measured neutron lifetimes differ depending on the measurement methods, an experiment with a pulsed neutron beam at J-PARC is in progress. In this experiment, neutrons are bunched into 40-cm lengths using a spin flip chopper (SFC), where the statistical sensitivity was limited by the aperture size of the SFC. The SFC comprises three sets of magnetic supermirrors and two resonant spin flippers. In this paper, we discuss an upgrade to enlarge the apertures of the SFC. With this upgrade, the statistics per unit time of the neutron lifetime experiment increased by a factor of 2.8, while maintaining a signal-to-noise ratio of 250–400, which is comparable to the previous one. Consequently, the time required to reach a precision of 1 s in the neutron lifetime experiment was reduced from 590 to 170 days, which is a significant reduction in time. This improvement in the statistics will also contribute to the reduction of systematic uncertainties, such as background evaluation, fostering further advancements in the neutron lifetime experiments at J-PARC.DOI： 10.1093/ptep/ptae123
Other Link： https://academic.oup.com/ptep/article-pdf/2024/9/093G01/59179657/ptae123.pdf
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Circular polarization measurement for individual gamma rays in capture reactions with intense pulsed neutrons Reviewed Open Access
Shunsuke Endo, Ryota Abe, Hiroyuki Fujioka, Takashi Ino, Osamu Iwamoto, Nobuyuki Iwamoto, Shiori Kawamura, Atsushi Kimura, Masaaki Kitaguchi, Ryuju Kobayashi, Shoji Nakamura, Takayuki Oku, Takuya Okudaira, Mao Okuizumi, Mohamed Omer, Gerard Rovira, Tatsushi Shima, Hirohiko M. Shimizu, Toshiyuki Shizuma, Yoshitaka Taira, Shusuke Takada, Shingo Takahashi, Hiromoto Yoshikawa, Tamaki Yoshioka, Heishun Zen
The European Physical Journal A Vol. 60 ( 8 ) 2024.8
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Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC
DOI： 10.1140/epja/s10050-024-01392-6
Other Link： https://link.springer.com/article/10.1140/epja/s10050-024-01392-6/fulltext.html
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Development of instruments for imaging of local magnetic structure by magnetic neutron holography Reviewed Open Access
Tomoya Kanno, Kenji Ohoyama, Hajime Nakada, Yuto Fukui, Kota Yamakawa, Shota Hoshi, Motoki Takano, Yodai Kobayashi, Yuka Tomimatsu, Shingo Takahashi, Takayuki Oku, Takuya Okudaira, Ryuju Kobayashi, Shusuke Takada, Masahide Harada, Kenichi Oikawa, Yasuhiro Inamura, Toetsu Shishido, Keisuke Sato, Kouichi Hayashi
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Vol. 1064 page： 169349 - 169349 2024.7
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Publishing type：Research paper (scientific journal) Publisher：Elsevier BV
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Present Status of Spectroscopy of the Hyperfine Structure and Repolarization of Muonic Helium Atoms at J-PARC Reviewed Open Access
Seiso Fukumura, Patrick Strasser, Mahiro Fushihara, Yu Goto, Takashi Ino, Ryoto Iwai, Sohtaro Kanda, Shiori Kawamura, Masaaki Kitaguchi, Shoichiro Nishimura, Takayuki Oku, Takuya Okudaira, Hirohiko M. Shimizu, Koichiro Shimomura, Hiroki Tada, Hiroyuki A. Torii
Physics Vol. 6 ( 2 ) page： 877 - 890 2024.6
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Publishing type：Research paper (scientific journal) Publisher：MDPI AG
The mass mμ− of the negative muon is one of the parameters of the elementary particle Standard Model and it allows us to verify the CPT (charge–parity–time) symmetry theorem by comparing mμ− value with the mass mμ+ of the positive muon. However, the experimental determination precision of mμ− is 3.1ppm, which is an order of magnitude lower than the determination precision of mμ+ at 120ppb. The authors aim to determine mμ− and the magnetic moment μμ− with a precision of O(10ppb) through spectroscopy of the hyperfine structure (HFS) of muonic helium-4 atom (4Heμ−e−) under high magnetic fields. He4μ−e− is an exotic atom where one of the two electrons of the He4 atom is replaced by a negative muon. To achieve the goal, it is necessary to determine the HFS of He4μ−e− with a precision of O(1ppb). This paper describes the determination procedure of the HFS of He4μ−e− in weak magnetic fields reported recently, and the work towards achieving the goal of higher precision measurement.
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New muonic He atom HFS measurements at J-PARC MUSE Reviewed
Yu Goto, Seiso Fukumura, Patrick Strasser, Takashi Ino, Ryoto Iwai, Sohtaro Kanda, Shiori Kawamura, Masaaki Kitaguchi, Shoichiro Nishimura, Takayuki Oku, Takuya Okudaira, Hirohiko M. Shimizu, Koichiro Shimomura, Hiroki Tada, Hiroyuki A. Torii
Interactions Vol. 245 ( 1 ) 2024.4
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Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC
DOI： 10.1007/s10751-024-01912-2
Other Link： https://link.springer.com/article/10.1007/s10751-024-01912-2/fulltext.html
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Contrast dependence of scattering profiles for poly(ethylene glycol) in water: Investigation by small-angle neutron scattering with 3He spin filter and small-angle x-ray scattering Reviewed Open Access
Akiyuki Ryoki, Fumi Watanabe, Takuya Okudaira, Shingo Takahashi, Takayuki Oku, Kosuke Hiroi, Ryuhei Motokawa, Yo Nakamura
The Journal of Chemical Physics Vol. 160 ( 11 ) 2024.3
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Language：English Publishing type：Research paper (scientific journal) Publisher：AIP Publishing
The small-angle neutron scattering (SANS) and small-angle x-ray scattering (SAXS) measurements were performed for deuterated and non-deuterated poly(ethylene glycol) (d-PEG and h-PEG, respectively) in D2O and a D2O/H2O mixed solvent (Mix) to compare the scattering profiles. To determine the coherent scattering intensity of SANS, a 3He spin filter was utilized. The scattering profiles determined by the SANS measurements were analyzed in terms of the wormlike chain model with touched beads along the contour of the chain. However, the SAXS profiles were not explained by the same model with uniform beads but with beads each consisting of a core and a shell having different electron densities. To explore the chain thickness determined from the SANS profile, the scattering intensities for different combinations of d-PEG/D2O, d-PEG/Mix, h-PEG/D2O, and h-PEG/Mix were also examined.
DOI： 10.1063/5.0192680
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Shusuke Takada, Masaki Fujita, Yu Goto, Takashi Honda, Kazutaka Ikeda, Yoichi Ikeda, Takashi Ino, Koji Kaneko, Ryuju Kobayashi, Manabu Okawara, Takayuki Oku, Takuya Okudaira, Toshiya Otomo, Shingo Takahashi
Proceedings of 11th International Workshop on Sample Environment at Scattering Facilities (ISSE Workshop Nasu 2022) 2024.3
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Publishing type：Research paper (international conference proceedings) Publisher：Journal of the Physical Society of Japan
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Endo, H; Michibayashi, K; Okudaira, T; Mainprice, D
MINERALS Vol. 14 ( 3 ) 2024.3
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Publisher：Minerals
Ultramylonites are among the most extreme fault rocks that commonly occur in the mid-crustal brittle–plastic transition and are mainly characterized by intensely sheared fine-grained microstructures and well-mixed mineral phases. Although the deformation mechanism of ultramylonites is key to understanding the rheological behavior of the mid-crustal shear zone, their microstructural development is still controversial owing to their intensely fine-grained textures. To investigate the possible crustal deformation mechanisms, we studied 13 mylonites obtained from the Kashio shear zone along the Median Tectonic Line that is the largest strike-slip fault in Japan. In particular, we investigated various mixed quartz–plagioclase layers developed within tonalitic mylonite, which are representative of the common mean grain size and crystal fabric of quartz among the studied samples. A high-quality phase-orientation map obtained by electron backscattered diffraction showed not only a wide range of quartz–plagioclase mixing (10%–80% in quartz modal composition) but also revealed a correlation between grain size reduction and crystal fabric weakening in quartz, indicating a change in the deformation mechanism from dislocation creep to grain-size-sensitive creep in the mixed quartz-plagioclase layers. In contrast, plagioclase showed an almost consistent fine grain size and weak to random crystal fabrics regardless of modal composition, indicating that grain size-sensitive creep is dominant. Combined with laboratory-determined flow laws, our results show that the Kashio shear zone could have developed under deformation mechanisms in which the viscosities of quartz and plagioclase are nearly comparable, effectively within 1017–1019 Pa·s, thereby possibly enabling extensive shearing along the Median Tectonic Line.
DOI： 10.3390/min14030229
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Endo, S; Kawamura, S; Okudaira, T; Yoshikawa, H; Rovira, G; Kimura, A; Nakamura, S; Iwamoto, O; Iwamoto, N
EUROPEAN PHYSICAL JOURNAL A Vol. 59 ( 12 ) 2023.12
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Publisher：European Physical Journal A
Neutron total and capture cross sections of Lanthanum(La)-139 were measured at the Accurate Ne-utron-Nucleus Reaction measurement Instrument (ANNRI) of the Materials and Life Science Experimental Facility (MLF) in the Japan Proton Accelerator Research Complex (J-PARC). The total cross section was deduced from transmission measurement using a Li-glass detector in the energy range from 0.5 to 1500 eV, and the capture cross section was measured by a NaI detector in the energy range from 0.5 to 74 eV. The total cross section was largely different from that in evaluated libraries, such as JENDL-5, in the energy range from 80 to 900 eV. Resonance parameters for four resonances including one negative resonance were obtained using a resonance analysis code, REFIT. The resonance analysis revealed discrepancies in several resonance parameters with the evaluated libraries. Furthermore, the information about the scattering radius was also extracted from the results of the total cross section. The obtained scattering radius was larger than that recorded in the evaluated libraries.
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Current status of the polarized La target development for T-violation search with slow neutron
Ide I., Fujita M., Hotta H., Iinuma M., Ikeda Y., Ito Y., Iwata T., Kitaguchi M., Kohri H., Miura D., Miyachi Y., Okudaira T., Shimizu H.M., Takanashi Y., Yosoi M.
Proceedings of Science Vol. 433 2023.8
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Publisher：Proceedings of Science
We are addressing the development of a polarized lanthanum (139La) target by applying a standard dynamic nuclear polarization (DNP) technique to a single crystal of lanthanum aluminate (LaAlO3) doped with neodymium ions (Nd3+), which is very attractive to search for violating effects of the time-reversal invariance with neutrons. The use of the LaAlO3 crystals as target material is very crucial to extend the spin-lattice relaxation time (T1) through the optimization of the Nd3+ concentration. We have almost established a method for precise control of the Nd3+ amount and this method has allowed us to grow the crystal with 0.01 mol% concentration differently from the 0.05 mol% reached before. Simple DNP experiments using a single-shot dewar at 1.3 K and 2.3 T allowed the evaluation of the T1 and the maximum polarization of these crystals. By that we have found that the 0.01 mol% concentration is the best one among the crystals tested in the past. Both, T1 and the maximum polarization of the 0.01 mol% crystal, have not been exactly obtained because of the long relaxation time, Thus, the preparation of a new DNP system is in progress toward DNP experiments for long-term measurement.
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Application of the Epithermal Polarized Neutron Beam at ANNRI in J-PARC
Endo Shunsuke, Okudaira Takuya
hamon Vol. 33 ( 2 ) page： 68 - 72 2023.5
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Language：Japanese Publisher：The Japanese Society for Neutron Science
<p>Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) is installed at the one of the beamlines in MLF in J-PARC, and nuclear reaction measurements have been conducted using the three types of <i>γ</i>-ray detectors, Ge, NaI, and LaBr. Recently, a <sup>3</sup>He spin filter to polarize neutrons has become available in ANNRI, and several experiments have been performed using the produced polarized neutrons. Significant differences in the measured cross section and <i>γ</i>-ray emission depending on the direction of the neutron polarization were observed in the <sup>117</sup>Sn(n,<i>γ</i>)<sup>118</sup>Sn reaction. A <i>γ</i>-ray polarimeter was also developed, and the circular polarization of emitted <i>γ</i>-rays was successfully measured at ANNRI for the <sup>32</sup>S(n, <i>γ</i>)<sup>33</sup>S reaction using the polarized neutrons.</p>
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The first polarized neutron diffraction experiment at the time-of-flight single crystal neutron diffractometer SENJU at J-PARC Reviewed Open Access
S. Takahashi, R. Kiyanagi, R. Kobayashi, T. Okudaira, T. Ino, J. Suzuki, K. Kakurai, T. Oku
Journal of Physics: Conference Series Vol. 2481 ( 1 ) 2023
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Publishing type：Research paper (international conference proceedings)
The 3He spin filter has been developed to use pulsed neutrons effectively at J-PARC MLF. In this study, the 3He spin filter was installed in the single crystal neutron diffractometer (BL18 SENJU) at J-PARC MLF as a polarizer of the incident beam, and Half-polarized neutron diffraction experiments were performed. The 3He spin filter was used the "drop-in cell"method with cells that had a relaxation time of 150 hours in the past experiments. The sample was a single crystal of Heusler crystal Cu2MnAl and the sample magnetic field was 0.3 T. The intensities of (111) Bragg peaks of Cu2MnAl were drastically changed with the polarity of the incident neutron beam, and the flipping ratio of 21.7 at 3.6 Å was observed. The experimental setup and the performance of the 3He spin filter used in this experiment are described in detail in this paper.
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J-PARC ANNRIビームラインにおける偏極熱外中性子利用
遠藤 駿典, 奥平 琢也
日本中性子科学会誌 波紋 Vol. 33 page： 68 - 72 2023
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Optically Polarized Alkali Metal Cell for Muonic Helium Measurements Reviewed
Takashi Ino, Seiso Fukumura, Patrick Strasser, Masaki Fujita, Yoichi Ikeda, Sohtaro Kanda, Masaaki Kitaguchi, Shoichiro Nishimura, Takayuki Oku, Takuya Okudaira, Hirohiko M. Shimizu, Koichiro Shimomura
Proceedings of the 24th International Spin Symposium (SPIN2021) 2022.12
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Publishing type：Research paper (international conference proceedings) Publisher：Journal of the Physical Society of Japan
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Angular distribution of γ rays from the p -wave resonance of Sn 118 Reviewed Open Access
J. Koga, S. Takada, S. Endo, H. Fujioka, K. Hirota, K. Ishizaki, A. Kimura, M. Kitaguchi, Y. Niinomi, T. Okudaira, K. Sakai, T. Shima, H. M. Shimizu, Y. Tani, T. Yamamoto, H. Yoshikawa, T. Yoshioka
Physical Review C Vol. 105 ( 5 ) 2022.5
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The neutron energy-dependent angular distribution of γ rays from the Sn117(n,γ) reaction was measured with germanium detectors and a pulsed neutron beam. The angular distribution was clearly observed in γ-ray emissions with an energy of 9327 keV which corresponds to the transition from a neutron resonance of Sn117+n to the ground state of Sn118. The angular distribution causes an angular-dependent asymmetric resonance shape. An asymmetry ALH was defined as (NL-NH)/(NL+NH), where NL and NH are integrated values for lower- and higher-energy regions of a neutron resonance, respectively. We found that the ALH has the angular dependence of (Acosθγ+B), where θγ is the γ-ray emission angle with respect to the incident neutron momentum, with A=0.394±0.073 and B=0.118±0.029 in the 1.33 eV p-wave resonance.
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Development of a <sup>3</sup>He Spin Filter and Its Application at J-PARC
Okudaira Takuya
hamon Vol. 32 ( 2 ) page： 76 - 81 2022.5
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Language：Japanese Publisher：The Japanese Society for Neutron Science
<p><sup>3</sup>He spin filter is a useful neutron polarization device as a neutron polarizer and an analyzer in neutron scattering experiments because of its capabilities to polarize neutrons in broad energy range and cover wide solid angle. We are developing a <sup>3</sup>He spin filter, based on the Spin Exchange Optical Pumping (SEOP) for polarized neutron scattering experiments at Materials and Life Science Experimental Facility (MLF) of J-PARC. A <sup>3</sup>He gas-filling station was constructed at J-PARC, and several <sup>3</sup>He cells with long spin relaxation times have been fabricated. A compact pumping systems with laser powers of 110 W was developed, and a <sup>3</sup>He polarization of 85 % was achieved under real experimental conditions. Several user experiments utilizing the <sup>3</sup>He spin filter are now being conducted at several beamlines at MLF. The development and utilization of <sup>3</sup>He spin filters at MLF of J-PARC are reported.</p>
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Proposal for new measurements of muonic helium hyperfine structure at J-PARC Reviewed
Seiso Fukumura, Patrick Strasser, Takashi Ino, Takayuki Oku, Takuya Okudaira, Sohtaro Kanda, Masaaki Kitaguchi, Koichiro Shimomura, Hirohiko M. Shimizu, Hiroyuki A. Torii, Shoichiro Nishimura
EPJ Web of Conferences Vol. 262 page： 01012 - 01012 2022.4
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The measurement of the ground state hyperfine structure of muonic helium has the potential to improve the precision of the mass of the negative muon by a factor of 50 or more. The mass of the negative muon is very important because it enables us to test the CPT theorem by comparison with positive muon mass. We aim to measure the hyperfine structure of muonic helium with a precision 1000 times higher than previous experiments [1,2] using the highintensity muon beam at J-PARC and have already obtained results better than the current precision in zero-field measurements in a test experiment in March 2021. To further improve the precision, we plan to measure in a high magnetic field and incorporate a technique that can produce highly polarized muonic helium atom [3]. In this paper, we will report on these developments.
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Erratum: Transverse asymmetry of γ rays from neutron-induced compound states of <sup>140</sup>La (Physical Review C (2020) 101 (064624) DOI: 10.1103/PhysRevC.101.064624) Reviewed
T. Yamamoto, T. Okudaira, S. Endo, H. Fujioka, K. Hirota, T. Ino, K. Ishizaki, A. Kimura, M. Kitaguchi, J. Koga, S. Makise, Y. Niinomi, T. Oku, K. Sakai, T. Shima, H. M. Shimizu, S. Takada, Y. Tani, H. Yoshikawa, T. Yoshioka
Physical Review C Vol. 105 ( 3 ) 2022.3
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We correct the sign of thetraverse asymmetry ALR in our previous paper The transverse asymmetry is derived from the correlation term snk? , where sn and k? are polarization of incident neutrons and momentum of emitted ? rays, respectively. The neutron polarization direction was determined using two measurements: (1) the measurement of the polarization direction of the circularly polarized laser which is used to polarize the 3He nuclei of the neutron polarizer, and (2) the measurement of the neutron polarization direction as it passes through the 3He neutron polarizer using a magnetic supermirror. However, in (1), the relation between the direction of the circular polarization and the spin of photons was misevaluated. Additionally, in (2), the relation between the neutron polarization direction reflected by the magnetic supermirror and the magnetic field applied to the magnetic supermirror was also misevaluated. Upon reevaluation we have deduced that the neutron polarization direction during the experiment was opposite to what was previously reported, and, hence, the sign of ALR should be reversed. As supporting evidence, the direction of the circular polarization of our laser system was obtained by measuring the electric paramagnetic resonance signal of Rb during laser pumping. The neutron polarization direction was also determined from the measurement of the parity violation at the 0.74-eV p-wave resonance of 139 La + n using our 3He neutron polarizer. These results also support that the neutron polarization direction was opposite to what was previously reported. Consequently, the transverse asymmetries for ? rays emitted in the transition from the 0.74-eV p-wave resonance to the ground state and inclusive ? rays are newly obtained as Agnd LR = - 0.60 ± 0.19 and Ainc LR = - 0.0045 ± 0.0080 , respectively. Similarly, Figs. 9, 11, 13, and 15 in the original paper should be replaced as Figs. 9, 11, 13, and 15 in this Erratum, respectively. The corrections do not affect results and conclusions of the original article. (Figure Presented).
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J-PARC における高性能 3He 中性子スピンフィルタの開発とその先導研究
奥平 琢也
波紋 Vol. 32 page： 76 - 81 2022
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Measurement of Angular Distributions of \(\gamma \)-rays from 139La+n to Excited States of 140La Reviewed
Takuya Okudaira, Shunsuke Endo, Hiroyuki Fujioka, Katsuya Hirota, Kohei Ishizaki, Atsushi Kimura, Masaaki Kitaguchi, Jun Koga, So Makise, Yudai Niinomi, Kenji Sakai, Tatsushi Shima, Hirohiko M. Shimizu, Shusuke Takada, Yuika Tani, Tomoki Yamamoto, Hiromoto Yoshikawa, Tamaki Yoshioka
Proceedings of the 3rd J-PARC Symposium (J-PARC2019) 2021.3
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Study of Neutron–Nuclear Spin Correlation Term with a Polarized Xe Target Reviewed
Kenji Sakai, Takayuki Oku, Takuya Okudaira, Tetsuya Kai, Masahide Harada, Kosuke Hiroi, Hirotoshi Hayashida, Kazuhisa Kakurai, Hirohiko M. Shimizu, Katsuya Hirota, Tomoki Yamamoto, Takashi Ino
Proceedings of the 3rd J-PARC Symposium (J-PARC2019) 2021.3
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Study of \(\gamma \)-ray from 4.53 eV p-wave Resonance of 111Cd Using Compound Nuclear Reaction Reviewed
S. Makise, S. Endo, H. Fujioka, K. Hirota, K. Ishizaki, A. Kimura, M. Kitaguchi, J. Koga, Y. Niinomi, T. Okudaira, K. Sakai, T. Shima, H. M. Shimizu, S. Takada, Y. Tani, T. Yamamoto, H. Yoshikawa, T. Yoshioka
Proceedings of the 3rd J-PARC Symposium (J-PARC2019) 2021.3
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Study for the Experimental Sensitivity of T-violation Search in Compound Nuclear Reaction of 117Sn Reviewed
J. Koga, S. Endo, H. Fujioka, K. Hirota, K. Ishizaki, A. Kimura, M. Kitaguchi, S. Makise, Y. Niinomi, T. Okudaira, K. Sakai, T. Shima, H. M. Shimizu, S. Takada, Y. Tani, T. Yamamoto, H. Yoshikawa, T. Yoshioka
Proceedings of the 3rd J-PARC Symposium (J-PARC2019) 2021.3
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Hiromoto Yoshikawa, Shunsuke Endo, Hiroyuki Fujioka, Katsuya Hirota, Kohei Ishizaki, Atsushi Kimura, Masaaki Kitaguchi, Jun Koga, So Makise, Yudai Niinomi, Takuya Okudaira, Kenji Sakai, Tatsushi Shima, Hirohiko M. Shimizu, Shusuke Takada, Yuika Tani, Tomoki Yamamoto, Tamaki Yoshioka
Proceedings of the 3rd J-PARC Symposium (J-PARC2019) 2021.3
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Measurement of γ rays from <sup>6</sup>LiF tile as an inner wall of a neutron-decay detector Reviewed Open Access
J. Koga, S. Ieki, A. Kimura, M. Kitaguchi, R. Kitahara, K. Mishima, N. Nagakura, T. Okudaira, H. Otono, H. M. Shimizu, N. Sumi, S. Takada, T. Tomita, T. Yamada, T. Yoshioka
Journal of Instrumentation Vol. 16 ( 2 ) 2021.2
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A neutron lifetime measurement conducted at the Japan Proton Accelerator Research Complex (J-PARC) is counting the number of electrons from neutron decays with a time projection chamber (TPC). The γ rays produced in the TPC cause irreducible background events. To achieve the precise measurement, the inner walls of the TPC consist of 6Li-enriched lithium-fluoride (6LiF) tiles to suppress the amount of γ rays. In order to estimate the amount of γ rays from the 6LiF tile, prompt gamma ray analysis (PGA) measurements were performed using germanium detectors. We reconstructed the measured γ-ray energy spectrum using a Monte Carlo simulation with the stripping method. Comparing the measured spectrum with a simulated one, the number of γ rays emitted from the6LiF tile was (2.3+0.7-0.3) × 10-4 per incident neutron. This is 1.4+0.5-0.2 times the value assumed for a mole fraction of the 6LiF tile. We concluded that the amount of γ rays produced from the 6LiF tile is not more twice the originally assumed value.
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T. Okudaira, T. Oku, K. Sakai, T. Ino, H. Hayashida, K. Hiroi, T. Shinohara, K. Kakurai, K. Aizawa
Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques Vol. 14 ( S1 ) page： S165 - S168 2020.10
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DOI： 10.1134/s1027451020070356
Other Link： https://link.springer.com/article/10.1134/S1027451020070356/fulltext.html
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Measurement and analysis reports on angular dependence of γ rays emitted from <sup>111</sup>Cd specific p-wave resonance for compound nuclear reaction
Makise S., Ishizaki K., Endo S., Okudaira T., Kitaguchi M., Kimura A., Koga J., Sakai K., Shima T., Shimizu H. M., Takada S., Tani Y., Niinomi Y., Hirota K., Fujioka H., Yamamoto T., Yoshioka T., Yoshikawa H., NOPTREX collaboration
Meeting Abstracts of the Physical Society of Japan Vol. 75.1 page： 308 - 308 2020
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Experimental test of <sup>3</sup>He neutron-spin filter in MIEZE spectrometer Reviewed
H. Hayashida, M. Hino, H. Endo, T. Oku, T. Okudaira, K. Sakai, T. Oda
Journal of Physics: Conference Series Vol. 1316 ( 1 ) 2019.12
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© Published under licence by IOP Publishing Ltd. A modulated intensity by zero effort (MIEZE) spectrometer is a type of neutron-resonance spin-echo spectrometer and can be used to analyze the slow dynamics of condensed matter by measuring the intermediate scattering function I(Q,τ). A crucial feature of a MIEZE spectrometer is it leaves completely free the space between the sample and the detector because the sample is placed after the neutron-spin analyzer. Measuring the magnetic dynamics with a conventional neutron-spin-echo spectrometer is difficult, but with a MIEZE spectrometer such a measurement may be done simply by introducing a second analyzer after the sample. Measuring the magnetic dynamics with high precision requires the background to be reduced to a minimum and is a job for which a 3He neutron-spin filter (3He-NSF) is a promising candidate as a second analyzer. However, one difficulty with this approach is the diffusion of 3He gas from the 3He-NSF, which may be measured and interpreted as dynamics. Therefore, we investigate herein whether the dynamics of gas diffusion is detected when using a 3He-NSF as second analyzer in a MIEZE spectrometer. Toward this end, we experimented with the MIEZE spectrometer installed at beamline 06 (BL06) at the Materials and Life Science Experimental Facility at Japan Proton Accelerator Research Complex (J-PARC MLF). The results confirm that the gas-diffusion dynamics of the 3He-NSF are not detected, and that the 3He-NSF, therefore, can be used as a second analyzer in this MIEZE spectrometer.
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Measurement of the angular distribution of γ-rays after neutron capture by 139La for a T-violation search Reviewed
Takuya Okudaira, Hirohiko M. Shimizu, Masaaki Kitaguchi, Katsuya Hirota, Christopher C. Haddock, Ikuya Ito, Tomoki Yamamoto, Shunsuke Endo, Kohei Ishizaki, Takumi Sato, Shusuke Takada, Jun Koga, Tamaki Yoshioka, Takashi Ino, Kouichiro Asahi, Takamasa Momose, Takahiro Iwata, Takayuki Oku, Kenji Sakai, Atsushi Kimura, Taro Nakao, Masanori Hino, Tatsushi Shima, Yutaka Yamagata
EPJ Web of Conferences 2019.12
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Search for Time Reversal Violation using Compound Nuclei Invited Reviewed
奥平琢也
波紋 Vol. 29 ( 3 ) page： 126‐132 2019.8
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Review on the formation and growth of cerebral aneurysms
Fukuda S., Shimogonya Y., Nakamura M., Yamada T., Suzuki K., Yamamoto Y., Kanou K., Okada N., Pan F., Okudaira T., Kuwahara S.
Journal of Biorheology Vol. 33 ( 2 ) page： 43 - 52 2019
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Publisher：Journal of Biorheology
A cerebral aneurysm is a vascular condition characterized by local ballooning of an artery in the brain. Although aneurysm formation and growth are thought to be the result of destruction of the blood vessel wall, the details of the etiology are unclear. We review the formation and growth of cerebral aneurysms as follows. In the first part, we summarize the history of theories on the pathogenesis of cerebral aneurysm in chronological order from epidemiological and pathological viewpoints and based on data obtained from animal models of experimentally induced cerebral aneurysms, with a focus on the involvement of hemodynamic stress on the arterial wall. In the second part, we review computational fluid dynamics (CFD) studies on the initiation of cerebral aneurysms with a brief overview of the history of CFD in hemodynamics analysis. Of the hypotheses presented, strong emphasis is placed on that of high wall shear stress and a high wall shear stress gradient. Other leading hypotheses involving hemodynamics-related parameters are also reviewed. In the third part, we review CFD studies on the growth of cerebral aneurysms, in which hemodynamic parameters were compared between growing and stable aneurysms, to highlight the hemodynamic characteristics associated with their growth.
DOI： 10.17106/jbr.33.43
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Development of the neutron polarizer for the T-violation search using compound nuclei Reviewed
T. Okudaira, T. Oku, K. Sakai, T. Ino, H. Hayashida, K. Hiroi, T. Shinohara, K. Kakurai, K. Aizawa, H. M. Shimizu, M. Kitaguchi, T. Yamamoto
Proceedings of Science Vol. 356 2019
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© Copyright owned by the author(s). The fundamental parity violation is enhanced by 106 times at maximum in several neutron induced compound nuclei. There is a theoretical prediction that fundamental T-violating effects can be also largely enhanced in compound nuclei implying that T-violation can be searched for by making very sensitive measurements. A T-violation search experiment using compound nuclei is planned at J-PARC. Polarized epithermal neutron beam, polarized nuclear target, and high count rate neutron detector are necessary for the experiment, and therefore a development of the neutron polarizer using polarized 3He is ongoing at J-PARC in JAEA. Recently, a clean vacuum system to fabricate 3He spin filters was constructed, and several 3He spin filters were fabricated. The current status of the development of the 3He spin filter was reported.
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Verification of the compound nuclear model for T-violation search Reviewed Open Access
T. Yamamoto, H. M. Shimizu, K. Ishizaki, Y. Niinomi, M. Kitaguchi, S. Takada, J. Koga, S. Makise, T. Yoshioka, A. Kimura, K. Sakai, T. Oku, T. Okudaira, S. Endo, Y. Tani, H. Fujioka, H. Yoshikawa, K. Hirota, T. Shima
Proceedings of Science Vol. 356 2019
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Large sources of parity violation have been observed in compound nuclear reactions. These enhancements are described by the compound nuclear model, which can be used to describe the angular correlation of γ-rays produced in (n; γ) reactions in medium-heavy nuclei. It has also been suggested that these same reactions could lead to a similar enhancement in time reversal violating processes. Therefore, we are interested in verifying the compound nuclear model by studying the (n; γ) reaction using polarized neutrons. In this paper, we discuss the installation and characterization of a neutron polarizer used in the (n; γ) measurement with transversely polarized neutrons.
DOI： 10.22323/1.356.0042
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Development of the neutron polarizer for the T-violation search using compound nuclei
Okudaira T.
Proceedings of Science Vol. 356 2019
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Measurement of P-Violation in 139La(n,γ)140La – a first step towards a T-Violation search Reviewed
Tomoki Yamamoto, Hirohiko M. Shimizu, Masaaki Kitaguchi, Katsuya Hirota, Christopher C. Haddock, Shunsuke Endo, Kohei Ishizaki, Takumi Sato, Shusuke Takada, Jun Koga, Tamaki Yoshioka, Takashi Ino, Koichiro Asahi, Takamasa Momose, Takahiro Iwata, Kenji Sakai, Takuya Okudaira, Takayuki Oku, Atsushi Kimura, Masahiro Hino, Tatsushi Shima, Yutaka Yamagata
EPJ Web of Conferences Vol. 219 page： 09002 - 09002 2019
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Language：English Publishing type：Research paper (scientific journal) Publisher：{EDP} Sciences
<jats:p>We performed a polarized neutron transmission asymmetry measurement utilizing the <jats:sup>139</jats:sup>La(<jats:italic>n</jats:italic>,γ)<jats:sup>140</jats:sup>La reaction. This measurement involved the use of a recently developed <jats:sup>3</jats:sup>He spin filter mounted on the J-PARC MLF beam line number 4 (BL04). The resulting value of the longitudinal asymmetry <jats:italic>A</jats:italic><jats:sub><jats:italic>L</jats:italic></jats:sub> = (11.7 ± 1.1)% was found to be in good agreement with existing values in the literature suggesting that the method by which we polarize the neutron beam is not a significant source of uncertainty. This preliminary work represents a first step toward future measurements of the angular correlation in (<jats:italic>n̅</jats:italic>,<jats:italic>Υ</jats:italic>) reactions necessary in the search for enhanced T-Violation in compound nuclei.</jats:p>
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Measurement of γ ray from 7.0 eV P-wave of <sup>113</sup>Cd using compound nuclear reaction for T-violation search
Makise S., Takada S., Koga J., Yoshioka T., Shimizu H. M., Yamamoto T., Ishizaki K., Endo Shunsuke, Sato T., Niinomi Y., Kitaguchi M., Hirota K., Shima T., Yoshikawa H., Fujioka H., Tani Y., Okudaira T., Kimura A., Sakai K., NOPTREX collaboration
Meeting Abstracts of the Physical Society of Japan Vol. 74.1 page： 273 - 273 2019
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Measurement of the angular distribution of prompt gamma-rays emitted in the 117Sn(n, γ) reaction for a T-violation search Reviewed
Jun Koga, Shusuke Takada, Tamaki Yoshioka, Hirohiko M. Shimizu, Katsuya Hirota, Norio Oi, Tomoki Yamamoto, Ikuya Ito, Kohei Ishizaki, Shunsuke Endo, Takumi Sato, Masaaki Kitaguchi, Christopher C. Haddock, Takuya Okudaira, Kenji Sakai, Atsushi Kimura
EPJ Web of Conferences Vol. 219 page： 09004 - 09004 2019
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<jats:p>It is theoretically suggested that the violation of charge conjugation and parity symmetry (CP-violation) could be enhanced in several compound nuclear reactions. According to the CPT theorem the violation of time-reversal symmetry (T-violation) would be enhanced too. The experimental sensitivity to find a T-violating effect in neutron-induced compound nuclear reactions depends on the value of a spin factor κ(<jats:italic>J</jats:italic>), which is a parameter specific for each nuclide. It can be determined from the angular dependence of γ-ray emission in (n,γ) reactions induced near a p-wave resonance. In this paper, the measurement result and the analysis status of experiments using the target nucleus <jats:sup>117</jats:sup>Sn are reported.</jats:p>
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Development of a Neutron Spin Filter for a T Violation Search in Compound Nuclei Reviewed
T. Yamamoto, H.M. Shimizu, M. Kitaguchi, K. Hirota, T. Okudaira, C.C. Haddock, N. Oi, I. Ito, S. Endo, S. Takada, J. Koga, T. Yoshioka, T. Ino, K. Asahi, T. Momose, T. Iwata, K. Sakai, T. Oku, A. Kimura, M. Hino, T. Shima, Y. Yamagata
JPS Conference Proceedings 2018.11
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Measurement of (n,gamma) Reaction of 117Sn for T-Violation Search by Using Compound Nucleus Reviewed
J. Koga, S. Takada, T. Yoshioka, H.M. Shimizu, K. Hirota, T. Okudaira, N. Oi, I. Ito, T. Yamamoto, S. Endo, C.C. Haddock, M. Kitaguchi, A. Kimura, K. Sakai, T. Ino, K. Asahi, T. Momose, T. Iwata, M. Hino, T. Shima, Y. Yamagata
JPS Conference Proceedings 2018.11
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Fundamental Physics Using High-Performance Optics Reviewed
Masaaki Kitaguchi, Koichiro Asahi, Shunsuke Endo, Christopher C. Haddock, Masahiro Hino, Katsuya Hirota, Takashi Ino, Ikuya Ito, Takahiro Iwata, Jun Koga, Yoshiyuki Miyachi, Takamasa Momose, Noriko Oi, Takuya Okudaira, Kenji Sakai, Tatsushi Shima, Hirohiko M. Shimizu, Shusuke Takada, Yutaka Yamagata, Tomoki Yamamoto, Tamaki Yoshioka
JPS Conference Proceedings 2018.11
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Language：English Publishing type：Research paper (other academic)
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A Search for Possible Long Range Spin Dependent Interactions of the Neutron From Exotic Vector Boson Exchange Reviewed Open Access
Christopher C. Haddock, Joseph Amadio, Eamon Anderson, Libertad Barron-Palos, Bret Crawford, Daniel Esposito, Walter Fox, Ian Francis, Jason Fry, Hanna Gardiner, Adam Holley, Kirill Korsak, Justin Lieffers, Scott Magers, Marissa Maldonado-Velazquez, Dimitry Mayorov, Jefferey Nico, Takuya Okudaira, Churamani Paudel, Satyaranjan Santra, Murad Sarsour, Hirohiko M. Shimizu, William M. Snow, Aaron Sprow, Kyle Steffen, Erik Swanson, Fredrik Tovesson, John Vanderwerp, Peter Yergeau
Physics Letters B 783 (2018) 227-233 Vol. 783 page： 227 - 233 2018.8
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We present a search for possible spin dependent interactions of the neutron<br />
with matter through exchange of spin 1 bosons with axial vector couplings as<br />
envisioned in possible extensions of the Standard Model. This was sought using<br />
a slow neutron polarimeter that passed transversely polarized slow neutrons by<br />
unpolarized slabs of material arranged so that this interaction would tilt the<br />
plane of polarization and develop a component along the neutron momentum. The<br />
result for the rotation angle, $\phi'_{V_5} =<br />
[2.8\pm\,4.6(stat.)\pm\,4.0(sys.)]\times 10^{-5}~\mbox{rad/m}$ is consistent<br />
with zero. This result improves the upper bounds on the neutron-matter coupling<br />
$g_{A}^{2}$ from such an interaction by about three orders of magnitude for<br />
force ranges in the mm-$\mu$m regime. -
Characterization of germanium detectors for the measurement of the angular distribution of prompt γ-rays at the ANNRI in the MLF of the J-PARC Reviewed Open Access
S. Takada, T. Okudaira, F. Goto, K. Hirota, A. Kimura, M. Kitaguchi, J. Koga, T. Nakao, K. Sakai, H. M. Shimizu, T. Yamamoto, T. Yoshioka
Journal of Instrumentation Vol. 13 ( 2 ) 2018.2
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© 2018 IOP Publishing Ltd and Sissa Medialab. In this study, the germanium detector assembly, installed at the Accurate Neutron-Nuclear Reaction measurement Instruments (ANNRI) in the Material and Life Science Facility (MLF) operated by the Japan Proton Accelerator Research Complex (J-PARC), has been characterized for extension to the measurement of the angular distribution of individual γ-ray transitions from neutron-induced compound states. We have developed a Monte Carlo simulation code using the GEANT4 toolkit, which can reproduce the pulse-height spectra of γ-rays from radioactive sources and (n,γ) reactions. The simulation is applicable to the measurement of γ-rays in the energy region of 0.5-11.0 MeV.
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Measurement of Angular Distributions in 139La(n,????) Reaction for T Violation Search Reviewed
T. Okudaira, H. M. Shimizu, M. Kitaguchi, K. Hirota, C. C. Haddock, N. Oi, I. Ito, T. Yamamoto, S. Endo, S. Takada, J. Koga, T. Yoshioka, T. Ino, K. Asahi, T. Momose, T. Iwata, K. Sakai, T. Oku, A. Kimura, M. Hino, T. Shima, Y. Yamagata
JPS Conference Proceedings, Proceedings of the International Conference on Neutron Optics (NOP2017) Vol. 22 ( 10.7566 ) page： 011041 2018
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Measurement of Angular Correlations In the (n, γ) Reaction for T Violation Search Reviewed
T. Okudaira, H. M. Shimizu, M. Kitaguchi, K. Hirota, S. Takada, T. Yamamoto, A. Okada, T. Yoshioka, T. Ino, K. Sakai, K. Asahi, T. Momose, T. Iwata, M. Hino, T. Shima, Y. Yamagata
Proceedings of Science, The 26th International Nuclear Physics Conference (INPC2016) Vol. INPC2016 ( 188 ) 2017.3
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Measurement of the cross section of neutron resonance in <sup>139</sup>La
Takeshita Hayato, Shimizu Hirohiko, Kitaguchi Masaaki, Hirota Katsuya, Ichikawa Go, Okudaira Takuya, Okada Anju, Goto Fumiya, Nagamoto Kosuke, Yamamoto Tomoki, Takada Shusuke, Yoshioka Tamaki, Ino Takashi, Asahi Koichiro, Momose Takamasa, Iwata Takahiri, Sakai Kenji, Hino Masahiri, Shima Tatsushi, Yamagata Yutaka, Kimura Atsushi
Meeting Abstracts of the Physical Society of Japan Vol. 72.1 ( 0 ) page： 360 - 360 2017
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Precise measurement of the angular correlations in the 139La(n, γ) reaction for T violation search
Okudaira T., Koga J., Yoshioka T., Ino T., Asahi K., Momose T., Iwata T., Sakai K., Kimura A., Hino M., Shima T., Shimizu H. M., Yamagata Y., Kitaguchi M., Hirota K., Haddock C. C., Oi N., Ito I., Yamamoto T., Takada S.
Meeting Abstracts of the Physical Society of Japan Vol. 72 ( 0 ) page： 256 - 256 2017
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Precise measurement of the angular correlations in the (n, γ) reaction for T violation search
Okudaira T., Yoshioka T., Ino T., Asahi K., Momose T., Iwata T., Sakai K., Kimura A., Hino M., Shima T., Yamagata Y., Shimizu H. M., Kitaguchi M., Hirota K., Okada A., Ito I., Yamamoto T., Takada S., Koga J.
Meeting Abstracts of the Physical Society of Japan Vol. 72 ( 0 ) page： 300 - 300 2017
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Measurement of angular correlation of (n,gamma) reaction with polarized neutrons
Yamamoto T.
Proceedings of Science Vol. 2017-January 2017
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Development of neutron polarizer for T-Violation searching in compound nucleus
Yamaomto T., Yoshioka T., Ino T., Asahi K., Momose T., Iwata T., Sakai K., Kimura A., Hino M., Shima T., Yamagata Y., Shimizu H. M., Kitaguchi M., Hirota K., Okudaira T., Okada A., Ito I., Takada S., Koga J.
Meeting Abstracts of the Physical Society of Japan Vol. 72 ( 0 ) page： 303 - 303 2017
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High Count Rate Neutron Detector for Search of T-Violation
Endo S., Koga J., Yoshioka T., Ino T., Asahi K., Momose T., Iwata T., Sakai K., Kimura A., Hino M., Shima T., Okudaira T., Yamagata Y., Shimizu H. M., Kitaguchi M., Hirota K., Okada A., Ito I., Yamamoto T., Takada S.
Meeting Abstracts of the Physical Society of Japan Vol. 72 ( 0 ) page： 356 - 356 2017
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Analysis of data of (n, γ) reaction of Br for T violation search
Ito I., Yoshioka T., Ino T., Asahi K., Momose T., Iwata T., Sakai K., Kimura A., Hino M., Shima T., Yamagata Y., Shimizu H. M., Kitaguchi M., Hirota K., Okudaira T., Okada A., Yamamoto T., Takada S., Koga J.
Meeting Abstracts of the Physical Society of Japan Vol. 72 ( 0 ) page： 302 - 302 2017
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Search for CP-violation effects in compound neutron resonance at J-PARC
Kitaguchi M., Shimizu H. M., Hirota K., Okudaira T., Oi N., Ito I., Yamamoto T., Endo S., Haddock C., Takada S., Koga J., Yoshioka T., Ino T., Asahi K., Momose T., Iwata T., Sakai K., Kimura A., Hino M., Shima T., Yamagata Y.
Meeting Abstracts of the Physical Society of Japan Vol. 72.2 ( 0 ) page： 255 - 255 2017
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Search for CP-violation effects in compound neutron resonance at J-PARC
Kitaguchi M., Yoshioka T., Ino T., Asahi K., Momose T., Iwata T., Sakai K., Kimura A., Hino M., Shima T., Yamagata Y., Shimizu H. M., Hirota K., Okudaira T., Okada A., Ito I., Yamamoto T., Takada S., Koga J.
Meeting Abstracts of the Physical Society of Japan Vol. 72 ( 0 ) page： 299 - 299 2017
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MISC 65
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Angular correlation between neutron spin and γ-ray mementum in <sup>139</sup>La(n,γ)<sup>140</sup>La<sup>*</sup> reactions
奥泉舞桜, 奥平琢也, 奥平琢也, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥隆之, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 78 ( 1 ) 2023
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Fundamental study of compound nuclei and T-violation search experiment
奥平琢也, 奥平琢也, 伊東佑起, 井出郁央, 遠藤駿典, 遠藤駿典, 奥隆之, 奥泉舞桜, 後藤優, 亀田健斗, 河村しほり, 北口雅暁, 木村敦, 中部倫太郎, 酒井健二, 嶋達志, 清水裕彦, 南部太郎, 西村岳太郎, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 78 ( 1 ) 2023
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The Installation of the <sup>3</sup>He Neutron Spin Filter to the Single Crystal Neutron Diffractometer SENJU (I).
高橋慎吾, 高橋慎吾, 鬼柳亮嗣, 小林龍珠, 小林龍珠, 奥平琢也, 奥平琢也, 猪野隆, 鈴木淳市, 加倉井和久, 高田秀佐, 高田秀佐, 池田陽一, 藤田全基, 奥隆之, 奥隆之
日本中性子科学会年会講演概要集 Vol. 23rd 2023
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Development of a laser system for the <sup>3</sup>He spin filter to polarize neutron beam
後藤優, 奥隆之, 奥隆之, 奥平琢也, 奥平琢也, 高田秀佐, 高橋慎吾, 小林龍珠, 猪野隆
日本物理学会講演概要集(CD-ROM) Vol. 78 ( 1 ) 2023
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Utilization of Polarized Neutrons at J-PARC MLF BL04 ANNRI
奥泉舞桜, 奥平琢也, 奥平琢也, 猪野隆, 遠藤駿典, 遠藤駿典, 奥隆之, 奥隆之, 加倉井和久, 河村しほり, 河村しほり, 北口雅暁, 木村敦, AUTON Clayton, AUTON Clayton, 後藤優, 小林龍珠, 小林龍珠, 高田秀佐, 高田秀佐, 高橋慎吾, 高橋慎吾, 清水裕彦
日本中性子科学会年会講演概要集 Vol. 23rd 2023
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Determination of the partial neutron width of 0.88 eV p-wave resonance of <sup>81</sup>Br for study of the systematics in parity-mixing nuclear matrix elements
吉川大幹, 遠藤駿典, 遠藤駿典, 奥平琢也, 奥平琢也, 河村しほり, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 西村岳太郎, 藤岡宏之, 吉岡瑞樹
日本物理学会講演概要集(CD-ROM) Vol. 78 ( 1 ) 2023
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Development of the Magnetic Field Measurement Device to Evaluate Homogeneous Magnetic Fields in the <sup>3</sup>He-SpinFilter Solenoid Coils II.
小林龍珠, 小林龍珠, 奥隆之, 奥隆之, 高橋慎吾, 高橋慎吾, 高田秀佐, 高田秀佐, 奥平琢也, 奥平琢也
日本中性子科学会年会講演概要集 Vol. 23rd 2023
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T-violation search using compound nuclei-measurement of the spin-dependent neutron absorption cross section with polarized nuclei-
奥平琢也, 奥平琢也, 石角元志, 伊東佑起, 井出郁央, 遠藤駿典, 遠藤駿典, 奥隆之, 奥隆之, 河村しほり, 神原理, 亀田健斗, 北口雅暁, 木村敦, 後藤優, 小林龍珠, 酒井健二, 篠原武尚, 嶋達志, 清水裕彦, 高田秀佐, 高田秀佐, 高橋慎吾, 高橋慎吾, 高橋竜太, 中部倫太郎, 広田克也, 藤家拓大, 藤家拓大, 土川雄介, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 77 ( 2 ) 2022
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Plan for the T-violation search using compound nuclei and measurement of the spin-dependent neutron absorption cross section with polarized nuclei
奥平琢也, 奥平琢也, 安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥隆之, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 77 ( 1 ) 2022
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Measurement of σ<sub>n</sub>・k<sub>γ</sub> angular dependent term of <sup>139</sup>La(n,γ)<sup>140</sup> La reaction for polarized neutrons
安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥隆之, 奥平琢也, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 長谷川拓郎, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 77 ( 1 ) 2022
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Development of the polarimeter for circular polarization measurement of gamma-rays emitted from neutron capture reactions.
遠藤駿典, 遠藤駿典, 安部亮太, 石崎貢平, 伊東佑起, 奥隆之, 奥平琢也, OMER Mohamed, 亀田健斗, 河村しほり, 北口雅暁, 木村敦, 酒井健二, 静間俊行, 嶋達志, 清水裕彦, 杉田健人, 全炳俊, 平義隆, 高田秀佐, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 77 ( 1 ) 2022
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The angular dependence of the cross section of <sup>115</sup>In(n, γ) reaction toward a search for time-reversal violation using an indium target.
高田秀佐, 安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥隆之, 奥平琢也, 奥平琢也, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 77 ( 1 ) 2022
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Prompt γ-ray measurement from the neutron capture reaction of Pd isotopes in the eV energy range
吉川大幹, 安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥平琢也, 奥平琢也, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 中井飛翔, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹
日本物理学会講演概要集(CD-ROM) Vol. 77 ( 1 ) 2022
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Measurement of the circular polarization of γ-rays from the <sup>139</sup>La(n,γ) <sup>140</sup>La reaction
遠藤駿典, 遠藤駿典, 奥平琢也, 亀田健斗, 河村しほり, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 77 ( 2 ) 2022
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Derivation of neutron partial width of 3.91 eV p-wave resonance in <sup>105</sup>Pd(n,γ) <sup>106</sup>Pd reaction
吉川大幹, 遠藤駿典, 遠藤駿典, 奥平琢也, 奥平琢也, 河村しほり, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 藤岡宏之, 吉岡瑞樹
日本物理学会講演概要集(CD-ROM) Vol. 77 ( 2 ) 2022
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Measurement of polarization dependence for capture cross-section of <sup>117</sup>Sn(<span style=text-decoration:overline>→n</span>,γ) reaction
遠藤駿典, 遠藤駿典, 安部亮太, 石崎貢平, 伊東佑起, 奥隆之, 奥平琢也, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 中井飛翔, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 76 ( 2 ) 2021
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Study of epithermal neutron optics for time-reversal violation search experiment with compound nuclei
藤家拓大, 藤家拓大, 安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥平琢也, 奥平琢也, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 中井飛翔, 広田克也, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 76 ( 2 ) 2021
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Branching ratio measurement of prompt gamma-rays from the compound resonances to the low lying states.
広田克也, 安部亮太, 石崎貢平, 猪野隆, 遠藤駿典, 遠藤駿典, 奥平琢也, 奥隆之, 木村敦, 北口雅暁, 古賀淳, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 谷結以花, 長谷川拓郎, 藤岡宏之, 堀田大稀, 山本知樹, 吉岡瑞樹, 吉川大幹
量子ビームサイエンスフェスタ(Web) Vol. 2020 2021
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Measurement of angular dependent term of <sup>139</sup>La(n,γ) reaction for polarized neutrons
安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥隆之, 奥平琢也, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 中井飛翔, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 76 ( 2 ) 2021
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Angular distribution of γ-rays from the neutron capture reaction of Pd isotopes in the eV energy range
吉川大幹, 安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥平琢也, 奥平琢也, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 中井飛翔, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹
日本物理学会講演概要集(CD-ROM) Vol. 76 ( 2 ) 2021
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Evaluation of resonance parameters of compound nuclear states in the n+<sup>131</sup>Xe reaction
亀田健斗, 安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥隆之, 奥平琢也, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 中井飛翔, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 76 ( 2 ) 2021
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Measurement of the γ-ray angular distribution in <sup>131</sup>Xe(n,γ)<sup>132</sup>Xe<sup>*</sup> reactions
奥平琢也, 奥平琢也, 安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥隆之, 亀田健斗, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 76 ( 2 ) 2021
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Present status of time-reversal violation search experiment with compound nuclei
北口雅暁, 安部亮太, 石崎貢平, 伊東佑起, 遠藤駿典, 遠藤駿典, 奥隆之, 奥平琢也, 亀田健斗, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 広田克也, 藤家拓大, 藤家拓大, 藤岡宏之, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 76 ( 2 ) 2021
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Measurement and current status of analysis of the angular dependence of γ-rays emitted from <sup>117</sup>Sn(n, γ) reactions
古賀淳, 石崎貢平, 遠藤駿典, 奥平琢也, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 谷結以花, 新實裕大, 広田克也, 藤岡宏之, 牧瀬壮, 山本知樹, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 75 ( 1 ) 2020
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Analysis of branching ratio of gamma-ray from In(n, γ) reaction for T-violation search using compound states
高田秀佐, 飯沼昌隆, 石崎貢平, 井出郁央, 遠藤駿典, 奥平琢也, 北口雅暁, 木村敦, 古賀淳, 酒井健二, 嶋達志, 清水裕彦, 谷結以花, 新實裕大, 広田克也, 藤家拓大, 藤岡宏之, 山本知樹, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 75 ( 2 ) 2020
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Analysis reports of p-wave resonance distribution caused by <sup>111</sup>Cd(n,γ)reactions for time reversal violation search experiment
牧瀬壮, 石崎貢平, 遠藤駿典, 奥平琢也, 北口雅暁, 木村敦, 古賀淳, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 谷結以花, 新實裕大, 広田克也, 藤岡宏之, 山本知樹, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 75 ( 1 ) 2020
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Study of <sup>131</sup>Xe(n,γ) reaction via compound nuclear state for T-violation search
谷結以花, 石崎貢平, 遠藤駿典, 奥平琢也, 北口雅暁, 木村敦, 古賀淳, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 新實裕大, 広田克也, 藤岡宏之, 牧瀬壮, 山本知樹, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 75 ( 1 ) 2020
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Development of waveform analysis method for high-precision test of the time-reversal symmetry via the compound process of the neutron resonance reaction
吉川大幹, 石崎貢平, 遠藤駿典, 奥平琢也, 北口雅暁, 木村敦, 古賀淳, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 谷結以花, 新實裕大, 広田克也, 藤家拓大, 藤岡宏之, 牧瀬壮, 山本知樹, 吉岡瑞樹
日本物理学会講演概要集(CD-ROM) Vol. 75 ( 1 ) 2020
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Measurement result of an angular dependence of γ-rays emitted by the <sup>117</sup>Sn(n, γ) reactions and comparison with previous study
古賀淳, 飯沼昌隆, 石崎貢平, 井出郁央, 遠藤駿典, 遠藤駿典, 奥平琢也, 北口雅暁, 木村敦, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 谷結以花, 新實裕大, 広田克也, 藤家拓大, 藤岡宏之, 山本知樹, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 75 ( 2 ) 2020
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複合核反応におけるCdの特定p波由来のγ線精密測定に関する研究
牧瀬壮, 石崎貢平, 遠藤駿典, 奥平琢也, 北口雅暁, 木村敦, 古賀淳, 酒井健二, 嶋達志, 清水裕彦, 高田秀佐, 谷結以花, 新實裕大, 広田克也, 藤岡宏之, 山本知樹, 吉岡瑞樹, 吉川大幹
日本物理学会講演概要集(CD-ROM) Vol. 74 ( 2 ) 2019
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複合核共鳴状態における時間反転対称性の破れ探索実験のための<sup>127</sup>I(n,γ)測定
佐藤匠, 清水裕彦, 山本知樹, 石崎貢平, 遠藤駿典, 新實裕大, 北口雅暁, 高田秀佐, 古賀淳, 牧瀬壮, 吉岡瑞樹, 広田克也, 嶋達志, 吉川大幹, 藤岡宏之, 谷結以花, 奥平琢也, 木村敦, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 74 ( 1 ) 2019
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複合核共鳴を用いた時間反転対称性の破れ探索に向けた<sup>139</sup>La(n,γ)反応におけるs波共鳴解析
吉川大幹, 嶋達志, 広田克也, 清水裕彦, 山本知樹, 石崎貢平, 遠藤駿典, 佐藤匠, 新實裕大, 北口雅暁, 高田秀佐, 古賀淳, 牧瀬壮, 吉岡瑞樹, 藤岡宏之, 谷結以花, 奥平琢也, 木村敦, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 74 ( 1 ) 2019
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Branching ratio measurement of prompt gamma-rays from the compound resonances to the low lying states.
広田克也, 石崎貢平, 猪野隆, 遠藤駿典, 奥平琢也, 奥隆之, 木村敦, 北口雅暁, 古賀淳, 酒井健二, 佐藤匠, 嶋達志, 清水裕彦, 高田秀佐, 谷結以花, 藤岡宏之, 牧瀬壮, 山本知樹, 吉岡瑞樹, 吉川大幹
量子ビームサイエンスフェスタ(Web) Vol. 2018 2019
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時間反転対称性の破れ探索のための複合核共鳴状態における<sup>111</sup>Cd及び<sup>113</sup>Cdの放出γ線角度分布測定
牧瀬壮, 高田秀佐, 古賀淳, 吉岡瑞樹, 清水裕彦, 山本知樹, 石崎貢平, 遠藤駿典, 佐藤匠, 新實裕大, 北口雅暁, 広田克也, 嶋達志, 吉川大幹, 藤岡宏之, 谷結以花, 奥平琢也, 木村敦, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 74 ( 1 ) 2019
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時間反転対称性の破れ探索に向けた<sup>81</sup>Br(n,γ)反応測定
遠藤駿典, 清水裕彦, 北口雅暁, 山本知樹, 石崎貢平, 佐藤匠, 吉岡瑞樹, 高田秀佐, 古賀淳, 嶋達志, 広田克也, 吉川大幹, 藤岡宏之, 谷結以花, 奥平琢也, 酒井健二, 木村敦
日本物理学会講演概要集(CD-ROM) Vol. 74 ( 1 ) 2019
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時間反転対称性の破れの探索に向けた<sup>103</sup>Rhの(n,γ)反応の測定
谷結以花, 藤岡宏之, 清水裕彦, 山本知樹, 石崎貢平, 遠藤駿典, 佐藤匠, 新實裕大, 北口雅暁, 古賀淳, 高田秀佐, 牧瀬壮, 吉岡瑞樹, 広田克也, 嶋達志, 吉川大幹, 奥平琢也, 木村敦, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 74 ( 1 ) 2019
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<sup>117</sup>Snの複合核反応における時間反転対称性の破れ探索に向けた実験感度に関する研究
古賀淳, 高田秀佐, 牧瀬壮, 吉岡瑞樹, 清水裕彦, 山本知樹, 石崎貢平, 遠藤駿典, 佐藤匠, 新實裕大, 北口雅暁, 広田克也, 嶋達志, 吉川大幹, 藤岡宏之, 谷結以花, 奥平琢也, 木村敦, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 74 ( 1 ) 2019
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複合核過程における<sup>139</sup>La及び<sup>109</sup>Agのs波共鳴解析
吉川大幹, 嶋達志, 清水裕彦, 広田克也, 山本知樹, 石崎貢平, 遠藤駿典, 遠藤駿典, 新實裕大, 北口雅暁, 高田秀佐, 古賀淳, 牧瀬壮, 吉岡瑞樹, 藤岡宏之, 谷結以花, 奥平琢也, 木村敦, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 74 ( 2 ) 2019
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佐藤匠, 清水裕彦, 北口雅暁, 広田克也, 石崎貢平, 遠藤駿典, 山本知樹, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, HADDOCK Christopher, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 奥平琢也, 奥隆之, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 73 ( 2 ) page： ROMBUNNO.14pS12‐3 - 69 2018.9
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山本知樹, 清水裕彦, 北口雅暁, 広田克也, 石崎貢平, 遠藤駿典, 佐藤匠, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, HADDOCK Christopher, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 奥平琢也, 奥隆之, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 73 ( 2 ) page： ROMBUNNO.14pS12‐1 - 67 2018.9
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複合核状態を用いた時間反転対称性の破れ探索に向けた偏極標的開発
石崎貢平, 清水裕彦, 北口雅暁, 広田克也, 山本知樹, 遠藤駿典, 佐藤匠, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, HADDOCK Christopher, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 奥平琢也, 奥隆之, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 73 ( 2 ) page： ROMBUNNO.14pS12‐4 - 70 2018.9
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複合核共鳴を用いた時間反転対称性破れ探索に向けた,<sup>81</sup>Br(n,γ)反応におけるγ線放出角度分布測定
遠藤駿典, 清水裕彦, 北口雅暁, 広田克也, 山本知樹, 石崎貢平, 佐藤匠, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, HADDOCK Christopher, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 奥平琢也, 奥隆之, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 73 ( 2 ) page： ROMBUNNO.14pS12‐2 - 68 2018.9
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複合核共鳴の時間反転対称性の破れ―<sup>81</sup>Brの(n,γ)反応の角分布測定―
伊藤維久弥, 清水裕彦, 広田克也, 奥平琢也, 大井法子, 山本知樹, 遠藤駿典, 佐藤匠, 石崎貢平, HADDOCK Christopher, 北口雅暁, 古賀淳, 高田秀佐, 吉岡瑞樹, 木村敦, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 73 ( 1 ) page： ROMBUNNO.25pK309‐7 - 403 2018.3
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複合核共鳴における時間反転対称性の破れ探索実験のためのTriplet‐DNPを用いた中性子スピンフィルターの開発
高田秀佐, 高田秀佐, 古賀淳, 吉岡瑞樹, 上坂友洋, 立石健一郎, 大竹淑恵, 池田義雅, 若林泰生, 清水裕彦, 広田克也, HADDOCK Christopher, 奥平琢也, 大井法子, 伊藤維久弥, 山本知樹, 石崎貢平, 遠藤駿典, 北口雅暁, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 73 ( 1 ) page： ROMBUNNO.25pK309‐9 - 404 2018.3
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複合核共鳴の時間反転対称性の破れ―<sup>117</sup>Snの(n,γ)反応の角分布測定―
古賀淳, 高田秀佐, 吉岡瑞樹, 清水裕彦, 広田克也, 奥平琢也, 大井法子, 伊藤維久弥, 山本知樹, 遠藤駿典, 石崎貢平, HADDOCK Christopher, 北口雅暁, 木村敦, 酒井健二
日本物理学会講演概要集(CD-ROM) Vol. 73 ( 1 ) page： ROMBUNNO.25pK309‐6 - 402 2018.3
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複合核反応における時間反転対称性の破れ探索実験に向けた研究
古賀淳, 高田秀佐, 吉岡瑞樹, 清水裕彦, 広田克也, 北口雅暁, 山本知樹, 石崎貢平, 遠藤駿典, 佐藤匠, 新實裕大, 藤家拓大, 藤岡宏之, 谷結以花, 嶋達志, 吉川大幹, 奥平琢也, 酒井健二
日本中性子科学会年会講演概要集 Vol. 18th 2018
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複合核反応における時間反転対称性の破れ探索実験に向けた研究
古賀淳, 高田秀佐, 吉岡瑞樹, 清水裕彦, 広田克也, 北口雅暁, 山本知樹, 石崎貢平, 遠藤駿典, 佐藤匠, 新實裕大, 藤家拓大, 藤岡宏之, 谷結以花, 嶋達志, 吉川大幹, 奥平琢也, 酒井健二
日本中性子科学会年会講演概要集 Vol. 18th 2018
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Measurement of parity violation of lanthanum-139 for the T-violation search in a compound nucleus
山本知樹, 清水裕彦, 北口雅暁, 広田克也, HADDOCK Christopher, 奥平琢也, 大井法子, 伊藤維久弥, 石崎貢平, 遠藤駿典, 佐藤匠, 吉岡瑞樹, 高田秀佐, 古賀淳, 木村敦, 酒井健二, 奥隆之
量子ビームサイエンスフェスタ(Web) Vol. 2017 2018
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Angular distribution of prompt gamma-ray from the <sup>117</sup>Sn(n,γ) reaction
古賀淳, 高田秀佐, 吉岡瑞樹, 清水裕彦, 広田克也, 奥平琢也, 大井法子, 伊藤維久弥, 山本知樹, 石崎貢平, 遠藤駿典, 佐藤匠, HADDOCK Christopher, 北口雅暁, 木村敦, 酒井健二
量子ビームサイエンスフェスタ(Web) Vol. 2017 2018
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複合核共鳴の時間反転対称性の破れ―<sup>117</sup>Sn及び<sup>115</sup>Inの(n,γ)反応測定の解析の現状―
古賀淳, 高田秀佐, 吉岡瑞樹, 清水裕彦, 広田克也, 奥平琢也, 大井法子, 伊藤維久弥, 山本知樹, 遠藤駿典, HADDOCK Christopher, 北口雅暁, 木村敦, 酒井健二, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 2 ) page： ROMBUNNO.13pS22‐3 - 257 2017.9
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北口雅暁, 清水裕彦, 広田克也, 奥平琢也, 伊藤維久弥, 山本知樹, 高田秀佐, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 2 ) page： ROMBUNNO.13pS22‐1 - 299 2017.9
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Language：Japanese Publisher：一般社団法人 日本物理学会
<p>中性子吸収反応による複合核共鳴状態では部分波干渉によって対称性の破れが増幅する。時間反転対称性の破れについても電気双極子能率を超えた感度を持つ可能性がある。現在候補となるいくつかの標的核について、増幅度を見積もるための測定を進めている。J-PARCでの実験計画について報告する。</p>
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複合核状態における時間反転対称性の破れ探索のための偏極中性子を用いた空間反転対称性の破れ測定
山本知樹, 清水裕彦, 北口雅暁, 広田克也, 奥平琢也, 大井法子, 伊藤維久弥, 遠藤駿典, HADDOCK Christopher, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 奥隆之, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 2 ) page： ROMBUNNO.13pS22‐4 - 258 2017.9
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複合核状態における時間反転対称性の破れ―時間反転対称性の破れ測定のための高計数率検出器の開発
遠藤駿典, 清水裕彦, 北口雅暁, 広田克也, 奥平琢也, 伊藤維久弥, 山本知樹, HADDOCK Christopher, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 2 ) page： ROMBUNNO.13pS22‐6 - 259 2017.9
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複合核状態における時間反転対称性の破れ―<sup>139</sup>La(n,γ)反応のγ線角分布の高精度測定:実験と解析
奥平琢也, 清水裕彦, 北口雅暁, 広田克也, HADDOCK C, 大井法子, 伊藤維久弥, 山本知樹, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 2 ) page： ROMBUNNO.13pS22‐2 - 256 2017.9
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複合核共鳴を用いた時間反転対称性の破れの探索のための偏極核標的に対する要請について
清水裕彦, Gudkov V, SNOW W. M, BOWMAN J. D, 北口雅暁, 広田克也, 奥平琢也, 岡田晏珠, 伊藤維久弥, 山本知樹, 高田秀佐, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 宮地義之, 酒井健二, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 2 ) page： ROMBUNNO.13pS22‐8 - 261 2017.9
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時間反転対称性の破れの探索における高計数率中性子検出器の開発
遠藤駿典, 清水裕彦, 北口雅暁, 広田克也, 奥平琢也, 岡田晏珠, 伊藤維久弥, 山本知樹, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 1 ) page： ROMBUNNO.18pC‐PS‐24 - 356 2017.3
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Language：Japanese Publisher：一般社団法人 日本物理学会
<p>我々は原子核の複合核共鳴を用いて、時間反転対称性の破れの探索に取り組んでいる。この実験において必要な統計数の確保のために、1Gcpsの検出計数を持つ中性子検出器が必要となる。しかし現行の検出器では十分とは言えず、高計数率を持つ中性子検出器の開発が必須である。その上で正確な中性子数の把握のために、γ線バックグラウンドの排除も必要となる。当講演では現状の開発の進捗及び今後の展望について報告する。</p>
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北口雅暁, 清水裕彦, 広田克也, 奥平琢也, 岡田晏珠, 伊藤維久弥, 山本知樹, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 1 ) page： ROMBUNNO.18aK23‐3 2017.3
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複合核状態における時間反転対称性の破れ探索のための中性子偏極デバイスの開発
山本知樹, 清水裕彦, 北口雅暁, 広田克也, 奥平琢也, 岡田晏珠, 伊藤維久弥, 高田秀佐, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 1 ) page： ROMBUNNO.18aK23‐9 - 303 2017.3
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Language：Japanese Publisher：一般社団法人 日本物理学会
<p>中性子共鳴吸収反応による複合核状態では部分波干渉によって空間反転対称性の破れが増幅されることが知られている。時間反転対称性も同様に増幅されることが示唆されている。我々はこの探索に向けて複合核状態での(n,γ)反応測定をJ-PARC BL04で進めている。講演では本実験において必要な中性子偏極デバイスの開発の現状について報告を行う。</p>
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伊藤維久弥, 清水裕彦, 北口雅暁, 広田克也, 奥平琢也, 岡田晏珠, 山本知樹, 高田秀佐, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 1 ) page： ROMBUNNO.18aK23‐8 - 302 2017.3
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Language：Japanese Publisher：一般社団法人 日本物理学会
<p>中性子共鳴吸収反応において時間反転対称性の破れが増幅されることが示唆されている。我々はこの探索に向けて候補となる原子核の(n,γ)反応の測定をJ-PARC BL04で進めている。本公演では、Brを使用した実験のデータの解析の結果について発表する。</p>
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複合核状態における時間反転対称性の破れ―(n,γ)反応の角相関項の高精度測定
奥平琢也, 清水裕彦, 北口雅暁, 広田克也, 岡田晏珠, 伊藤維久弥, 山本知樹, 高田秀佐, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 1 ) page： ROMBUNNO.18aK23‐6 - 300 2017.3
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Language：Japanese Publisher：一般社団法人 日本物理学会
<p>中性子共鳴吸収反応において時間反転対称性の破れが増幅されることが示唆されている。我々はこの探索に向けて複合核状態での(n,γ)反応を調査する実験をJ-PARC BL04で進めている。(n,γ)反応におけるγ線の角相関はFlambaumにより予言されているが、詳細な検証は未だ行われていない。本公演では前回公演よりも高精度化したγ線の角相関測定の結果と理論的予測との比較について論じる。</p>
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複合核共鳴を用いた時間反転対称性の破れの探索のための偏極核標的内での中性子偏極度の挙動について
清水裕彦, GUDKOV V, SNOW W.M, BOWMAN J.D, 北口雅暁, 広田克也, 奥平琢也, 岡田晏珠, 伊藤維久弥, 山本知樹, 高田秀佐, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 宮地義之, 酒井健二, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) Vol. 72 ( 1 ) page： ROMBUNNO.18aK23‐7 - 301 2017.3
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<p>複合核状態を利用したT-violationの研究では、偏極中性子を偏極核標的に入射させる。その際、P-violationやT-violationに無関係なスピンスピン相互作用の影響による中性子スピンの挙動を正しく評価しておくことが、微小なT-violationの探索を実行する上での前提となる。そこで偏極核標的内での中性子偏極度の挙動を考察し、その影響を抑制する方法について議論する。</p>
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Measurement of angular correlation of (n,gamma) reaction with polarized neutrons Reviewed
T. Yamamoto, H. M. Shimizu, M. Kitaguchi, K. Hirota, T. Okudaira, S. Takada, A. Okada, T. Yoshioka, T. Ino, K. Sakai, K. Asahi, T. Momose, T. Iwata, M. Hino, T. Shima, Y. Yamagata
Proceedings of Science Vol. 2017-January 2017
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© Copyright owned by the author(s). Large enhanced P violation in a nuclear resonance reaction has been observed by using a polarized neutron beam. Enhanced CP violation is predicted to exist within the same nuclear reaction. We are now preparing to supply a polarized neutron beam for a CP violation search experiment. In the enhancement process of CP violation, we assume that the P violation of the compound nuclear state doesn't depend on the final state. However this assumption has not been verified yet. We plan to verify the assumption by measuring the 139La(n,g ) reaction with a polarized neutron beam at J-PARC MLF BL04. The supplied neutron beam will be polarized by using 3He spin filter, which will be installed into BL04. We present the states of development for 3He spin filter and study of the equipment in BL04.
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石崎貢平, 伊藤維久弥, 山本知樹, 大井法子, 奥平琢也, HADDOCK Chris, 北口雅暁, 広田克也, 清水裕彦, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 宮地義之, 酒井健二, 日野正裕, 古賀淳, 高田秀佐, 吉岡瑞樹, 嶋達志, 山形豊
日本中性子科学会年会講演概要集 Vol. 17th page： 94 2017
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Measurement of neutron lifetime at J-PARC/BL05 : The analysis result of neutron capture gamma rays
Koga Jun, Yamada Takahito, Ieki Sei, Nagakura Naoki, Yamashita Satoru, Seki Yoshichika, Sumino Hirochika, Shimizu Hirohiko M, Hirota Katsuya, Okudaira Takuya, Yokohashi Mami, Sumi Naoyuki, Kitaguchi Masaaki, Mishima Kenji, Ino Takashi, Taketani Kaoru, Kimura Atsushi, Oide Hideyuki, Shima Tatsushi, Takada Shusuke, Tomita Tatsuhiko, Morishita Aya, Otono Hidetoshi, Yoshioka Tamaki, Kitahara Ryunosuke, Iwashita Yoshihisa
Meeting Abstracts of the Physical Society of Japan Vol. 72 ( 0 ) page： 64 - 64 2017
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<p>中性子寿命はCKM行列のVud項及びビッグバン元素合成論において重要なパラメータであり、これまで2手法で測定されてきた。しかし、両者の測定結果には8.4秒の乖離があり、異なる手法での測定が必要となる。本実験は検出器内で生じた中性子の崩壊を電子によって同定する。しかし、中性子捕獲反応由来のガンマ線が電子を発生させることがあり、これは背景事象となる。この背景事象を理解するためにJ−PARC/MLF/BL04で検出器と同素材の試料の中性子照射試験を行った。本講演ではその解析結果を報告する。</p>
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Measurement of the cross section of neutron resonance in <sup>139</sup>La
Takeshita Hayato, Yamamoto Tomoki, Takada Shusuke, Yoshioka Tamaki, Ino Takashi, Asahi Koichiro, Momose Takamasa, Iwata Takahiri, Sakai Kenji, Hino Masahiri, Shima Tatsushi, Shimizu Hirohiko, Yamagata Yutaka, Kimura Atsushi, Kitaguchi Masaaki, Hirota Katsuya, Ichikawa Go, Okudaira Takuya, Okada Anju, Goto Fumiya, Nagamoto Kosuke
Meeting Abstracts of the Physical Society of Japan Vol. 72 ( 0 ) page： 360 - 360 2017
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Presentations
Presentations 8
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Studying discrete symmetry violation in neutron-nucleus system Invited International conference
Okudaira Takuya
5th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan 2018.10.23
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Language：English Presentation type：Oral presentation (invited, special)
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3Heスピンフィルタの開発と利用 Invited
奥平琢也
日本物理学会年会
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Event date： 2021.2
Presentation type：Oral presentation (invited, special)
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J-PARCにおける3Heスピンフィルタの開発 Invited
奥平琢也
量子ビームサイエンスフェスタ
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Event date： 2020.2
Language：Japanese Presentation type：Oral presentation (invited, special)
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JAEAにおける偏極<sup>3</sup>He中性子スピンフィルター開発の現状
奥平琢也, 奥隆之, 酒井健二, 猪野隆, 林田洋寿, 廣井孝介, 篠原武尚, 加倉井和久, 相澤一也
日本中性子科学会年会講演概要集 2018
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Plan for T-Violation search in a compound nucleus
Yamamoto Tomoki, Yoshioka T, Ino Takashi, Haddock Christopher, Asahi Koichiro, Momose Takamasa, Iwata Takahiro, Sakai Kenji, Kimura Atsushi, Okudaira Takuya, Oku Takayuki, Shimizu Hirohiko M, Hino Masahiro, Shima Tatsushi, Yamagata Yutaka, Kitaguchi Masaaki, Hirota Katsuya, Ishizaki Kohei, Endo Shunsuke, Sato Takumi, Takada Shusuke, Koga Jun
Meeting Abstracts of the Physical Society of Japan 2018
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複合核状態における時間反転対称性の破れ―<sup>139</sup>La(n,γ)反応のγ線角分布の高精度測定:実験と解析
奥平琢也, 清水裕彦, 北口雅暁, 広田克也, HADDOCK C, 大井法子, 伊藤維久弥, 山本知樹, 高田秀佐, 古賀淳, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 木村敦, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) 2017.9.25
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複合核状態における時間反転対称性の破れ―(n,γ)反応の角相関項の高精度測定
奥平琢也, 清水裕彦, 北口雅暁, 広田克也, 岡田晏珠, 伊藤維久弥, 山本知樹, 高田秀佐, 吉岡瑞樹, 猪野隆, 旭耕一郎, 百瀬孝昌, 岩田高広, 酒井健二, 日野正裕, 嶋達志, 山形豊
日本物理学会講演概要集(CD-ROM) 2017.3.21
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Development of neutron spin filter for T violation search
Sato Takumi, Yoshioka Tamaki, Ino Takashi, Haddock Christopher, Asahi Koichiro, Momose Takamasa, Iwata Takahiro, Sakai Kenji, Kimura Atsushi, Okudaira Takuya, Oku Takayuki, Shimizu Hirohiko M, Hino Masahiro, Shima Tatsushi, Yamagata Yutaka, Hattori Mineyuki, Kitaguchi Masaaki, Hirota Katsuya, Ishizaki Kohei, Endo Shunsuke, Yamamoto Tomoki, Takada Shusuke, Koga Jun
Meeting Abstracts of the Physical Society of Japan 2018
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KAKENHI (Grants-in-Aid for Scientific Research)
KAKENHI (Grants-in-Aid for Scientific Research) 6
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Grant number：24H00222 2024.4 - 2027.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
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Authorship：Coinvestigator(s)
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多様化する核データ需要に対応するための共鳴の全角運動量測定基盤の構築
Grant number：24K08311 2024.4 - 2027.3
日本学術振興会 科学研究費助成事業 基盤研究(C)
遠藤 駿典, 奥平 琢也
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Authorship：Coinvestigator(s)
原子核が中性子を吸収して形成される複合核状態のパラメータである全角運動量は、複合核反応の記述において重要であるが、測定が困難であり現在の評価済核データライブラリーに掲載された全角運動量は、あくまで推定値であることが多くその正確性に大いに疑問が残る。本研究では大強度陽子加速器施設(J-PARC)の物質生命科学実験施設(MLF)の中性子ビームを用い、複数の手法で全角運動量を測定できる体制を構築することを目指す。これにより標的核における測定の向き不向きを踏まえ、多様な原子核に対する効率的かつ正確な全角運動量の測定が可能となる。
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Grant number：23K13122 2023.4 - 2026.3
日本学術振興会 科学研究費助成事業 若手研究
奥平 琢也
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Authorship：Principal investigator
Grant amount：\4680000 （ Direct Cost: \3600000 、 Indirect Cost：\1080000 ）
これまでの申請者らの研究によって、139Laや131Xeなどの中性子共鳴吸収反応において核子間相互作用におけるCP対称性の破れが約100万倍まで非常に大きく増幅されていることが明らかになった。これにより未知のCPの破れを高感度で探索できる可能性が示唆されている。CPの破れは偏極核標的と偏極中性子ビームのスピン依存する吸収断面積として測定される。本研究では近年開発された中性子偏極技術と131Xe偏極技術を用いて、核力ポテンシャルによる中性子スピン回転効果の抑制手法を実証した上で、CP対称性の破れ探索手法として確立することを目的とする。
原子核の中性子吸収反応において、時間反転対称性の破れが大きく増幅される可能性が示唆されており、この増幅機構を用いた感度の良い時間反転対称性の破れ探索実験を計画している。本研究ではこのための基礎研究を推進している。J-PARC MLFにて静的偏極139Laターゲットと偏極中性子ビームを用いて139Laと中性子のスピン依存する吸収断面積の測定を行った。時間反転対称性の破れが大きく増幅されている139Laの0.75eVのp波共鳴に対して初めてスピン依存する断面積の測定に成功し、そこからp波共鳴の中性子部分幅を決定することに成功した。これを用いて139La p波共鳴における時間反転対称性の破れの増幅率を決定した。これは中性子部分幅の終状態に依存しない決定であるとともに、全核種で初めてp波共鳴に対するスピン依存断面積を測定した結果である。本結果は素粒子原子核物理だけではなく、核データなどで重要となる複合核スピンの決定手法としても注目されている。
また中性子偏極デバイス用にビームラインに導入可能なレーザー偏極装置を開発し、中性子ビームラインにて動作テストを行なった。3日以上の長時間にわたり安定した中性子偏極率を達成できることが確認された。
これに加えて時間反転対称性の破れ探索実験の原理検証のためのスピン交換法を用いた偏極Xeターゲットの開発を推進している。電子スピン共鳴法を用いたXe偏極率絶対値の測定手法を開発し、高い信頼度で129Xeおよび131Xeの偏極率を決定することに成功した。
J-PARC MLFのトラブルにより一部のビーム実験が実施できなかったが、偏極Laと偏極中性子のスピン依存断面積の測定に成功していることから、概ね順調に計画は進行していると言える。
中性子偏極デバイスの性能をさらに改善することで、139Laと中性子のスピン依存断面積の測定実験の更なる高度化を行う。これに加え偏極Xeターゲットと偏極中性子ビームを用いた原理検証実験を推進する。 -
Development of determination method for neutron resonance spin using polarized neutron beam
Grant number：21K04950 2021.4 - 2024.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
Endo Shunsuke
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Aiming to establish an efficient and accurate method for determining the total angular momentum (spin) of compound nuclear resonances formed by the absorption of neutrons by atomic nuclei, a technique was developed to measure the circular polarization of gamma rays produced from polarized neutron capture reactions. A new gamma-ray polarimeter was developed as the device for measuring circular polarization, and performance evaluation tests were conducted. The results of the performance evaluation tests confirmed that the device has a sensitivity of approximately 2% to circular polarization. Additionally, the circular polarization of gamma rays produced by polarized neutron capture reactions was successfully measured at J-PARC MLF ANNRI.
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Development of the neutron polarization device for the CP-violation search
Grant number：20K14495 2020.4 - 2024.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists
Okudaira Takuya
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Authorship：Principal investigator
Grant amount：\4160000 （ Direct Cost: \3200000 、 Indirect Cost：\960000 ）
We have developed a neutron beam spin-polarization device: a 3He spin filter, which is indispensable for the CP violation search using a neutron absorption reaction by nuclei. The 3He spin filter is a device to polarize a neutron beam by using neutron absorption reaction of polarized 3He nuclei. A laser system for polarizing 3He gas was constructed at J-PARC, and it was confirmed that a high 3He polarization of about 80% can be achieved. An angular distribution of gamma-rays emitted from the polarized neutron absorption reaction by nuclei and a spin dependent absorption cross section of polarized La and polarized neutrons were successfully measured using this device.
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Grant number：19K21047 2018.8 - 2021.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up
Okudaira Takuya
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Authorship：Principal investigator
Grant amount：\2730000 （ Direct Cost: \2100000 、 Indirect Cost：\630000 ）
The objective of this research is to determine an enhancement factor of the CP-violation in compound nuclei of 139La+n by measuring an angular distribution of gamma-rays emitted in polarized neutron absorption reactions of 139La.
First, We developed high quality 3He spin filters in J-PARC to polarize a neutron beam. Then, the 3He spin filter was installed to a neutron beam line ANNRI, and the angular distribution of gamma-rays were measured with a germanium detector assembly. As a result, the angular distribution of gamma-rays depending on the neutron spin direction was found in the transition from 139La+n state to ground state of 140La. The theoretical study to interpret this result is now ongoing with collaborators.
Teaching Experience (On-campus)
Teaching Experience (On-campus) 4
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物理学実験
2024
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物理学実験
2023
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物理学実験
2022
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物理学実験
2021