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Journal Articles

Observation of adsorbed hydrogen species on supported metal catalysts by inelastic neutron scattering

Yoshida, Hisao*; Yamamoto, Akira*; Hosokawa, Saburo*; Yamazoe, Seiji*; Kikkawa, Soichi*; Hara, Kenji*; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Tanaka, Tsunehiro*

Topics in Catalysis, 64(9-12), p.660 - 671, 2021/08

 Times Cited Count:0 Percentile:0.01(Chemistry, Applied)

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

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

Freezable and unfreezable hydration water; Distinct contributions to protein dynamics revealed by neutron scattering

Yamamoto, Naoki*; Kofu, Maiko; Nakajima, Kenji; Nakagawa, Hiroshi; Shibayama, Naoya*

Journal of Physical Chemistry Letters (Internet), 12(8), p.2172 - 2176, 2021/03

 Times Cited Count:0 Percentile:0.01(Chemistry, Physical)

Hydration water plays a crucial role for activating the protein dynamics required for functional expression. Yet, the details are not understood about how hydration water couples with protein dynamics. A temperature hysteresis of the ice formation of hydration water is a key phenomenon to understand which type of hydration water, unfreezable or freezable hydration water, is crucial for the activation of protein dynamics. Using neutron scattering, we observed a temperature-hysteresis phenomenon in the diffraction peaks of the ice of freezable hydration water, whereas protein dynamics did not show any temperature hysteresis. These results show that the protein dynamics is not coupled with freezable hydration water dynamics, and unfreezable hydration water is essential for the activation of protein dynamics.

Journal Articles

Observation of Coulomb-assisted nuclear bound state of $$Xi^-$$-$$^{14}$$N system

Hayakawa, Shuhei; Fujita, Manami; Hasegawa, Shoichi; Hashimoto, Tadashi; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; et al.

Physical Review Letters, 126(6), p.062501_1 - 062501_6, 2021/02

 Times Cited Count:6 Percentile:97.77(Physics, Multidisciplinary)

Journal Articles

Identification of hydrogen species on Pt/Al$$_{2}$$O$$_{3}$$ by ${it in situ}$ inelastic neutron scattering and their reactivity with ethylene

Yamazoe, Seiji*; Yamamoto, Akira*; Hosokawa, Saburo*; Fukuda, Ryoichi*; Hara, Kenji*; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Tsukuda, Tatsuya*; Yoshida, Hisao*; Tanaka, Tsunehiro*

Catalysis Science & Technology, 11(1), p.116 - 123, 2021/01

 Times Cited Count:3 Percentile:81.22(Chemistry, Physical)

Journal Articles

Development of a Gd$$_{2}$$Si$$_{2}$$O$$_{7}$$ (GPS) scintillator-based alpha imaging detector for rapid plutonium detection in high-radon environments

Morishita, Yuki; Izaki, Kenji; Kaneko, Junichi*; Yamamoto, Seiichi*; Higuchi, Mikio*; Torii, Tatsuo

IEEE Transactions on Nuclear Science, 67(10), p.2203 - 2208, 2020/10

 Times Cited Count:2 Percentile:62.87(Engineering, Electrical & Electronic)

We developed a Gd$$_{2}$$Si$$_{2}$$O$$_{7}$$ (GPS) scintillator-based alpha imaging detector and demonstrated its effectiveness by evaluating actual Pu particle and $$^{222}$$Rn progeny. The GPS scintillator plate was prepared by a sintering method. The outer dimensions of the GPS scintillator plate were 5 $$times$$ 5 cm, and the scintillator layer was approximately 50 $$mu$$m on a 3-mm-thick high-transparency glass. The plate was optically coupled to a position-sensitive photomultiplier tube with silicone grease. The developed imaging detector exhibited good uniformity. Pu particle activities were accurately evaluated at 14 different positions, and the difference in activity was within 6%. Radon-222 ($$^{222}$$Rn) progeny counts were reduced by 65.3% by applying an energy window. Although the Pu/$$^{222}$$Rn progeny activity ratio was 1/51, the Pu particle was successfully identified among $$^{222}$$Rn progeny within the 5 min-measurement time. The imaging detector has an excellent ability for detecting Pu among $$^{222}$$Rn progeny. Thus, this detector is useful for alpha contamination monitoring in high-radon-background environments.

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

Weak-coupling mean-field theory of magnetic properties of NiGa$$_{2}$$S$$_{4}$$

Nomura, Takuji*; Yamamoto, Yuji*; Yoshii, Kenji

Journal of the Physical Society of Japan, 89(2), p.024704_1 - 024704_10, 2020/02

 Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)

We report a mean-field theoretical study of a triangular magnet NiGa$$_{2}$$S$$_{4}$$. Using the localized Wannier functions obtained from a band calculation, the most stable magnetic state was found to be spiral with the incommensurate structure, consistent with the result from neutron diffraction. The Ni-site Coulomb interaction was not strong (U about 2 eV). The spin value at the Ni site was also not so large about 1.1 mb. These results mean that the hybridization between Ni and S may play an important role. The dynamical spin correlation function was found to in accord with the results from neutron scattering.

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

A $$Sigma p$$ scattering experiment at J-PARC and the analysis status

Nakada, Yoshiyuki*; Hasegawa, Shoichi; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Nanamura, Takuya*; Naruki, Megumi*; Sako, Hiroyuki; Sato, Susumu; et al.

JPS Conference Proceedings (Internet), 26, p.023024_1 - 023024_5, 2019/11

Journal Articles

First $$gamma$$-ray spectroscopy of an $$sd$$-shell hypernucleus, $$^{19}_{Lambda}$$F

Yang, S. B.*; Hasegawa, Shoichi; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Tamura, Hirokazu*; Tanida, Kiyoshi; et al.

JPS Conference Proceedings (Internet), 26, p.023015_1 - 023015_5, 2019/11

Journal Articles

Study of $$Y^*$$ in nuclei through C$$(K^-, pi^+)X$$ spectrum at 1.8 GeV/$$c$$ in the J-PARC E05 experiment

Honda, Ryotaro*; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Imai, Kenichi; Ichikawa, Yudai; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; Sato, Susumu; et al.

JPS Conference Proceedings (Internet), 26, p.023014_1 - 023014_4, 2019/11

Journal Articles

Search for excited state of $$_{Sigma }^{4}{rm He}$$ hypernucleus in the J-PARC E13 experiment

Nakagawa, Manami*; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Tamura, Hirokazu; Tanida, Kiyoshi; et al.

JPS Conference Proceedings (Internet), 26, p.023005_1 - 023005_3, 2019/11

Journal Articles

Gamma-ray spectroscopy of single $$Lambda$$-hypernuclei at J-PARC; Results and perspective

Koike, Takeshi*; Hasegawa, Shoichi; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Sugimura, Hitoshi; Tamura, Hirokazu; et al.

AIP Conference Proceedings 2130, p.020011_1 - 020011_9, 2019/07

 Times Cited Count:1 Percentile:65.18

Journal Articles

Observation of a $$Xi$$ bound state in the $$^{12}$$C$$(K^-, K^+)$$ reaction at 1.8 GeV/$$c$$

Nagae, Tomofumi*; Ekawa, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Kimbara, Shinji; Nanamura, Takuya*; Naruki, Megumi; et al.

AIP Conference Proceedings 2130, p.020015_1 - 020015_9, 2019/07

Journal Articles

Localized magnetic excitations in the fully frustrated dimerized magnet Ba$$_{2}$$CoSi$$_{2}$$O$$_{6}$$Cl$$_{2}$$

Kurita, Nubuyuki*; Yamamoto, Daisuke*; Kanesaka, Takuya*; Furukawa, Nobuo*; Kawamura, Seiko; Nakajima, Kenji; Tanaka, Hidekazu*

Physical Review Letters, 123(2), p.027206_1 - 027206_6, 2019/07

 Times Cited Count:2 Percentile:35.62(Physics, Multidisciplinary)

Journal Articles

Observation of a Be double-Lambda hypernucleus in the J-PARC E07 experiment

Ekawa, Hiroyuki; Ashikaga, Sakiko; Hasegawa, Shoichi; Hashimoto, Tadashi; Hayakawa, Shuhei; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Kimbara, Shinji*; Nanamura, Takuya; et al.

Progress of Theoretical and Experimental Physics (Internet), 2019(2), p.021D02_1 - 021D02_11, 2019/02

 Times Cited Count:13 Percentile:85.21(Physics, Multidisciplinary)

Journal Articles

Optimization of thickness of GAGG scintillator for detecting an alpha particle emitter in a field of high beta and gamma background

Morishita, Yuki; Yamamoto, Seiichi*; Izaki, Kenji; Kaneko, Junichi*; Hoshi, Katsuya; Torii, Tatsuo

Radiation Measurements, 112, p.1 - 5, 2018/05

 Times Cited Count:7 Percentile:77.16(Nuclear Science & Technology)

To detect plutonium isotopes ($$^{238}$$Pu, $$^{239}$$Pu, and $$^{240}$$Pu) in a field of high beta and $$gamma$$ background, an alpha particle detector with low beta and $$gamma$$-ray sensitivity is required. Therefore, we optimized the thickness of the GAGG scintillator for alpha particle detection in a field of high beta and $$gamma$$ background. We prepared three GAGG scintillators with thicknesses of 0.05 mm, 0.07 mm, and 0.1 mm. Each of the GAGG scintillators was coupled optically to the SiPM array, which was used as the photodetector. Alpha, beta, and $$gamma$$ rays were irradiated onto the developed alpha particle detector, and their spectra were obtained. All GAGG scintillators used in this study were not sensitive to $$gamma$$ rays with a dose rate of 1 mSv/h. The beta count of the 0.05-mm-thick GAGG was only 1/100 that of the 0.1-mm-thick GAGG. Therefore, the 0.05-mm-thick GAGG scintillator is promising from the viewpoint of detecting plutonium contamination in a field with high beta and $$gamma$$ background.

247 (Records 1-20 displayed on this page)