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Journal Articles

Energy-dependent angular distribution of individual $$gamma$$ rays in the $$^{139}$$La($$n, gamma$$)$$^{140}$$La$$^{ast}$$ reaction

Okudaira, Takuya*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Ninomi, Yudai*; Sakai, Kenji; et al.

Physical Review C, 104(1), p.014601_1 - 014601_6, 2021/07

 Times Cited Count:0 Percentile:0.03(Physics, Nuclear)

Journal Articles

Polarization analysis for small-angle neutron scattering with a $$^{3}$$He spin filter at a pulsed neutron source

Okudaira, Takuya; Ueda, Yuki; Hiroi, Kosuke; Motokawa, Ryuhei; Inamura, Yasuhiro; Takata, Shinichi; Oku, Takayuki; Suzuki, Junichi*; Takahashi, Shingo*; Endo, Hitoshi*; et al.

Journal of Applied Crystallography, 54(2), p.548 - 556, 2021/04

 Times Cited Count:0 Percentile:0.02(Chemistry, Multidisciplinary)

Neutron polarization analysis (NPA) for small-angle neutron scattering (SANS) experiments using a pulsed neutron source was successfully achieved by applying a $$^{3}$$He spin filter as a spin analyzer for the scattered neutrons. The $$^{3}$$He spin filter covers a sufficient solid angle for performing SANS experiments, and the relaxation time of the $$^{3}$$He polarization is sufficient for continuous use over a few 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 hydrogen atoms in samples, is practically 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. This work is anticipated to greatly contribute 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.

Journal Articles

Study of neutron-nuclear spin correlation term with a polarized Xe target

Sakai, Kenji; Oku, Takayuki; Okudaira, Takuya; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke; Hayashida, Hirotoshi*; Kakurai, Kazuhisa*; Shimizu, Hirohiko*; Hirota, Katsuya*; et al.

JPS Conference Proceedings (Internet), 33, p.011116_1 - 011116_6, 2021/03

In neutron fundamental physics, study of correlation term $${bf s}cdot{bf I}$$ of a neutron spin $${bf s}$$ and a target nuclear spin $${bf I}$$ is important because $${bf s}cdot{bf I}$$ term interferes to parity non-conserving (PNC) and time reversal non-conserving terms. For this study, a xenon (Xe) is an interesting nucleus because it has been observed an enhancement of PNC effect around neutron resonance peaks, and polarizes up to $$ sim 10^{-1}$$ by using a spin exchange optical pumping (SEOP) method. We would plan to develop a polarized Xe gas target with a compact in-situ SEOP system, and to study $${bf s}cdot{bf I}$$ term by utilizing epithermal neutron beams supplied from a high intense pulsed spallation neutron source. As the first step, we attempted to measure neutron polarizing ability caused by $${bf s}cdot{bf I}$$ term at a 9.6 eV s-wave resonance peak of $$^{129}$$Xe at BL10 in MLF, by detecting change $$Delta R$$ of ratio between neutron transmissions with the polarized and unpolarized Xe target. After demonstrating that our apparatus could detect small change ($$Delta R_{rm DB} , {approx},10^{-2}$$) of neutron transmissions caused by Doppler broadening effect, a signified value of $$Delta R$$ has been obtained as preliminary results. For analyzing the obtained $$Delta R$$ in detail, we are improving our nuclear magnetic resonance and electron paramagnetic resonance systems for evaluating Xe polarization independently of neutron beams.

Journal Articles

Development and application of a $$^3$$He neutron spin filter at J-PARC

Okudaira, Takuya; Oku, Takayuki; Ino, Takashi*; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Takahashi, Shingo*; Aizawa, Kazuya; Endo, Hitoshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 977, p.164301_1 - 164301_8, 2020/10

 Times Cited Count:4 Percentile:76.41(Instruments & Instrumentation)

Journal Articles

Measurement of the angular distribution of $$gamma$$-rays after neutron capture by $$^{139}$$La for a T-violation search

Okudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.

EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12

Parity violating effects enhanced by up to 10$$^6$$ times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,$$gamma$$) reaction was measured with $$^{139}$$La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized $$^{139}$$La target and a 70% polarized $$^3$$He spin filter whose thickness is 70 atm$$cdot$$cm are needed. Therefore high quality $$^3$$He spin filter is developed in JAEA. The measurement result of the (n,$$gamma$$) reaction at J-PARC and the development status of the $$^3$$He spin filter will be presented.

Journal Articles

Development of the neutron polarizer for the T-violation search using compound nuclei

Okudaira, Takuya; Oku, Takayuki; Sakai, Kenji; Ino, Takashi*; Hayashida, Hirotoshi*; Hiroi, Kosuke; Shinohara, Takenao; Kakurai, Kazuhisa*; Aizawa, Kazuya; Shimizu, Hirohiko*; et al.

Proceedings of Science (Internet), 356, 5 Pages, 2019/12

The technology development section carries out the development of the neutron polarization device: $$^{3}$$He Spin Filter. It is often used for the fundamental physics region. In order to explain the matter-dominated universe, a time reversal violation is necessary and searches for new physics are conducted in the world. The T-violation search using a polarized neutron beam is planned at J-PARC. A large $$^{3}$$He spin filter is needed to polarize high energy neutrons for the experiment and is developed in JAEA. Recently, we developed the accurate measurement system to evaluate the polarization of $$^{3}$$He and a vacuum system to make the $$^{3}$$He spin filter, and large $$^{3}$$He spin filters for epi-thermal neutron was made using the system. The current status of the development of the $$^{3}$$He spin filter will be talked.

Journal Articles

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

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

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

 Times Cited Count:6 Percentile:62.89(Physics, Nuclear)

Journal Articles

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

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

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

 Times Cited Count:3 Percentile:26.36(Instruments & Instrumentation)

Oral presentation

Current status and future plan of a $$^{3}$$He spin filter development

Oku, Takayuki; Sakai, Kenji; Hiroi, Kosuke; Watanabe, Masao; Shinohara, Takenao; Aizawa, Kazuya; Kakurai, Kazuhisa; Kira, Hiroshi*; Hayashida, Hirotoshi*; Kiriyama, Koji*; et al.

no journal, , 

We have been developing a $$^{3}$$He neutron spin filter for applicaion at J-PARC MLF. The $$^{3}$$He neutron spin filter is avairable for neutrons in a wide energy range, and is also effective for a divergent neutron beam. Therefore, it is very useful in the neutron scattering experiment. So far, we have devleoped a compact laser optics with a volume holographic grating (VHG) elements, and have constructed an on-beam SEOP based $$^{3}$$He neutron spin filter. The olarization analysis tests were performed with the $$^{3}$$He neutron spin filter at several neutron beamlines for the sans, reflectivity and neutron imaging experiments. To extend the application range of the $$^{3}$$He neutron spin filter at J-PARC MLF, we plan to develop larger saize cells, higher power laser for the SEOP, and prepare working area for the filter inside the MLF experimental hall.

Oral presentation

Current status of a $$^{3}$$He spin filter development

Oku, Takayuki; Sakai, Kenji; Hiroi, Kosuke; Watanabe, Masao; Shinohara, Takenao; Aizawa, Kazuya; Kakurai, Kazuhisa*; Kira, Hiroshi*; Hayashida, Hirotoshi*; Kiriyama, Koji*; et al.

no journal, , 

We have been developing a $$^{3}$$He neutron spin filter for application at J-PARC MLF. The $$^{3}$$He neutron spin filter is available for neutrons in a wide energy range, and is also effective for a divergent neutron beam. Therefore, it is very useful in the neutron scattering experiment. So far, we have developed a compact laser optics with a volume holographic grating (VHG) elements, and have constructed an on-beam SEOP based $$^{3}$$He neutron spin filter. The polarization analysis tests were performed with the $$^{3}$$He neutron spin filter at several neutron beamlines for the sans, reflectivity and neutron imaging experiments. To extend the application range of the $$^{3}$$He neutron spin filter at J-PARC MLF, we plan to develop larger size cells, higher power laser for the SEOP, and prepare working area for the filter inside the MLF experimental hall.

Oral presentation

Study of neutron-nuclear spin correlation term with a polarized xenon target

Sakai, Kenji; Oku, Takayuki; Harada, Masahide; Kai, Tetsuya; Hiroi, Kosuke; Hayashida, Hirotoshi*; Kira, Hiroshi*; Shimizu, Hirohiko*; Hirota, Katsuya*; Okudaira, Takuya*; et al.

no journal, , 

no abstracts in English

Oral presentation

A Neutron depolarization measurement of a single crystal Fe by using a $$^3$$He neutron spin filter and magnetic super-mirrors

Oku, Takayuki; Kira, Hiroshi*; Hayashida, Hirotoshi*; Sakai, Kenji; Hiroi, Kosuke; Okudaira, Takuya; Ino, Takashi*; Shinohara, Takenao; Suzuki, Junichi*; Kakurai, Kazuhisa*; et al.

no journal, , 

We performed demonstrative experiments using the $$^3$$He-NSF at small-angle scattering (BL15 TAIKAN), reflection (BL17 SHARAKU) and imaging instrument (BL22 RADEN) of J-PARC MLF, and got reasonable results. Then, we have performed a demonstrative study of polarized-neutron single-crystal diffraction measurement at BL18 (SENJU). The sample was a single crystal Fe. As the result, expected flipping ratios of Bragg beaks were not observed. Therefore, we have performed a depolarization experiment of neutrons transmitted through the sample, and found out neutron severe depolarization occurred in the sample which was almost magnetically saturated under an applied magnetic field of 4.2 kG. In this paper, we will show the experimental results of the depolarization experiment of neutrons transmitted through the single crystal Fe and discuss them.

Oral presentation

Sample environment at J-PARC MLF

Oku, Takayuki; Watanabe, Masao; Sakaguchi, Yoshifumi*; Kawamura, Seiko; Takahashi, Ryuta*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ishikado, Motoyuki*; Ouchi, Keiichi*; Arima, Hiroshi*; et al.

no journal, , 

Sample environment team at the Materials and Life Science Experimental Facility in J-PARC has worked on development and operation of cryogenics, magnets, high temperature, high pressure, soft matter related items and special environment including pulsed magnets, light irradiators and He-3 spin filters. In the talk, our status is presented, and issues are addressed.

Oral presentation

Studying discrete symmetry violation in neutron-nucleus system

Okudaira, Takuya

no journal, , 

The technology development section carries out the development of the neutron polarization device. Polazied neutrons are used frequently in the experiment of the particle physics. Therefore. it is necessary to cooperate with the scientists in particle physics for further developments. The matter-dominated universe cannot be explained by the standard model, and searches for new physics are carried out in the world. One of the ways is a measurement of symmetry violation using polarized neutrons and nuclei. For example, experiments to measure parity violation using the polarized neutrons and light nuclei are conducted to search for the unknown physics in quark-quark interaction. The unknown time reversal violation can be enhanced in La(n, $$gamma$$) with polarized neutrons, and the fundamental study to search for T-violation is ongoing using MLF. We will present the overview of the experiments for symmetry violation using polarized neutrons and the neutron polarization device.

Oral presentation

Current status of the development of the $$^{3}$$He spin filter in JAEA

Okudaira, Takuya; Oku, Takayuki; Sakai, Kenji; Ino, Takashi*; Hayashida, Hirotoshi*; Hiroi, Kosuke; Shinohara, Takenao; Kakurai, Kazuhisa*; Aizawa, Kazuya

no journal, , 

$$^3$$He spin filter is a neutron polarization device composed of polarized $$^3$$He gas and alkali metal encapsulated into a special glass cell. Since a neutron absorption cross section of $$^3$$He has very large spin dependence, a polarized neutron beam for a wide energy range can be obtained passing through the polarized $$^3$$He gas. $$^3$$He nuclei are polarized irradiating a circularly polarized laser, which is referred to as Spin Exchange Optical Pumping method. The development of the $$^3$$He spin filter is ongoing in JAEA. Recently a spin flip technique of $$^3$$He using frequency sweep NMR and a measurement system of $$^3$$He polarization using electron paramagnetic resonance were developed. Additionally, a vacuum system to make $$^3$$He spin filter is also constructed.

Oral presentation

Study of neutron-nuclear spin correlation term with a polarized xenon target

Sakai, Kenji; Oku, Takayuki; Okudaira, Takuya; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke; Hayashida, Hirotoshi*; Shimizu, Hirohiko*; Yamamoto, Tomoki*; Ino, Takashi*; et al.

no journal, , 

In neutron fundamental physics, a study of correlation term $${bf s}cdot{bf I}$$ of a neutron spin s and a target nuclear spin $${bf I}$$ is important because the $${bf s}cdot{bf I}$$ term interferes to parity non-conserving (PNC) and time reversal non-conserving (TRNC) terms. For this study, a xenon (Xe) is an interesting nucleus because it has been observed an enhancement of PNC effect around neutron resonance peaks, and polarizes up to $$10^{-2}sim 10^{-1}$$ by using a spin exchange optical pumping (SEOP) method. We attempted to develop a polarized Xe target in a compact ${it in situ}$ SEOP system and measure neutron polarizing ability caused by the $${bf s}cdot{bf I}$$ term at a 9.6 eV $$s$$-wave resonance peak of $$^{129}$$Xe, by detecting change $$Delta R_P$$ of a ratio between neutron transmissions with the polarized and unpolarized Xe target. As preliminary results, we observed a signified value of $$Delta R_{P} approx 0.01$$ after demonstrating that our apparatus could distinguish Doppler broadening effect as systematic error.

Oral presentation

Development of the $$^{3}$$He neutron spin filter at JAEA

Okudaira, Takuya; Oku, Takayuki; Sakai, Kenji; Ino, Takashi*; Hayashida, Hirotoshi*; Hiroi, Kosuke; Shinohara, Takenao; Kakurai, Kazuhisa*; Aizawa, Kazuya

no journal, , 

The technology development section carries out the development of the neutron polarization device: $$^{3}$$He Spin Filter. $$^3$$He spin filter is a neutron polarization device composed of polarized $$^3$$He gas and alkali metal encapsulated into a special glass cell. Since a neutron absorption cross section of $$^3$$He has very large spin dependence, a polarized neutron beam can be obtained passing through the polarized $$^3$$He gas. $$^3$$He nuclei are polarized irradiating a circularly polarized laser (Spin Exchange Optical Pumping method). The development of the $$^3$$He spin filter is ongoing in JAEA. A system for the electron paramagnetic resonance, which can measure the $$^3$$He polarization without the neutron beam, was developed. Additionally, a vacuum system to make $$^3$$He spin filter was constructed and the development of high quality $$^3$$He spin filter using Rb and K (Hybrid SEOP) is also ongoing. The current status of the development at JAEA will be presented.

Oral presentation

The Development of the $$^{3}$$He spin filter for the time reversal violation search using compound nuclei at JAEA

Okudaira, Takuya; Oku, Takayuki; Sakai, Kenji; Ino, Takashi*; Hayashida, Hirotoshi*; Hiroi, Kosuke; Shinohara, Takenao; Kakurai, Kazuhisa*; Aizawa, Kazuya; Shimizu, Hirohiko*; et al.

no journal, , 

The technology development section carries out the development of the neutron polarization device: $$^{3}$$He Spin Filter. Since this device is often used for the fundamental physics region, it is important to cooperate with scientists in this region for further development. In order to explain the matter-dominated universe, a time reversal violation is necessary and searches for new physics are conducted in the world. The T-violation search experiment using a polarized neutron beam is planned at J-PARC. A large $$^{3}$$He spin filter is needed to polarize epi-thermal neutron for the experiment and is developed in JAEA. Recently, user's experiments for the T-violation search using $$^{3}$$He spin filter were conducted. The current status of the development of the $$^{3}$$He spin filter and feature plan will be presented.

Oral presentation

Measurement of polarization dependence for capture cross-section of $$^{117}$$Sn($$overrightarrow{n}$$,$$gamma$$) reaction

Endo, Shunsuke; Abe, Ryota*; Ishizaki, Kohei*; Oku, Takayuki; Okudaira, Takuya*; Kameda, Kento*; Kitaguchi, Masaaki*; Kimura, Atsushi; Sakai, Kenji; Shima, Tatsushi*; et al.

no journal, , 

no abstracts in English

Oral presentation

Measurement of the $$gamma$$-ray angular distribution in $$^{131}$$Xe(n,$$gamma$$)$$^{132}$$Xe* reactions

Okudaira, Takuya*; Abe, Ryota*; Ishizaki, Kohei*; Ito, Yuki*; Endo, Shunsuke; Oku, Takayuki; Kameda, Kento*; Kitaguchi, Masaaki*; Kimura, Atsushi; Sakai, Kenji; et al.

no journal, , 

no abstracts in English

26 (Records 1-20 displayed on this page)