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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

Morphological reproductive characteristics of testes and fertilization capacity of cryopreserved sperm after the Fukushima accident in raccoon (${it Procyon lotor}$)

Komatsu, Kazuki*; Iwasaki, Tsugumi*; Murata, Kosuke*; Yamashiro, Hideaki*; Goh, V. S. T.*; Nakayama, Ryo*; Fujishima, Yohei*; Ono, Takumi*; Kino, Yasushi*; Shimizu, Yoshinaka*; et al.

Reproduction in Domestic Animals, 56(3), p.484 - 497, 2021/03

We have established an archive system of livestock and wild animals from the surrounding ex-evacuation zone. Wildlife within the alert zone have been exposed to low-dose-rate (LDR) radiation for a long and continuous time. In this study, we analysed the morphological characteristics of the testes and in vitro fertilization (IVF) capacity of cryopreserved sperm of raccoons from the ex-evacuation zone of the FDNPP accident. This study revealed that the chronic and LDR radiation exposure associated with the FDNPP accident had no adverse effect on the reproductive characteristics and functions of male raccoons.

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

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

Measurement system of the background proton in DeeMe experiment at J-PARC

Yamamoto, Kazami; Saha, P. K.; Aoki, Masaharu*; Mihara, Satoshi*; Nakatsugawa, Yohei*; Shimizu, Kosuke*; Kinsho, Michikazu

JPS Conference Proceedings (Internet), 8, p.012004_1 - 012004_5, 2015/09

The existence of a mu-e conversion process is expected by some theories beyond the standard model in particle physics, but has not been discovered yet due to its low probability. The DeeMe experiment, proposed at J-PARC Material Life Science Facility (MLF), is planned to find the mu-e conversion process on a Muon production target. In order to distinguish mu-e event signal from a background, the number of a proton that comes after hundreds of nanoseconds from the main beam should be less than one per one hour during the DeeMe experiment. Therefore we designed a new measurement system to confirm low background level. A simulation result showed that the new system could detect such delayed proton.

Journal Articles

Investigation of causes of a failed steam jet and devising an improved jet design

Shimizu, Ryo; Takaya, Akikazu; Shirozu, Hidetomo; Uchida, Naoki; Tanaka, Kosuke; Yamaguchi, Akira; Aoto, Kazumi; Watahiki, Masaru

Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(3), p.203 - 212, 2005/09

It was occurred that process solution leaked from the steam jet in the acid recovery process of Tokai reprocessing plant. So we retrieved the jet from the cell and observed the inside. As a result, it was revealed that a defect by corrosion, which penetrated the inside of the structure, arose from the steam nozzle root in the suction room of the jet. To ascertain why such failure occurred, we carried out observation of metallurgical structure of the jet, an analysis of temperature distribution of the structure involving verification using mock-ups and evaluation of material by corrosion test. Consequently, the origin of the corrosion defect was pin hole which was occurred on the surface of the end of the material at the steam nozzle root, where nitric acid fluid was contacted, and then the defect progressed along the temperature of about 120 of the structure. Anisotropy of the material, possibly originating in the manufacturing process, was observed from the result of evaluation of material by corrosion test. Finally, we devised a new design of improved corrosion resistance on the result of the whole investigations.

Journal Articles

Microscopic structure of the Gamow-Teller resonance in $$^{58}$$Cu

Hara, Keigo*; Adachi, Takeshi*; Akimune, Hidetoshi*; Daito, Izuru*; Fujimura, Hisako*; Fujita, Yoshitaka*; Fujiwara, Mamoru; Fushimi, Kenichi*; Hara, Kaoru*; Harakeh, M. N.*; et al.

Physical Review C, 68(6), p.064612_1 - 064612_9, 2003/12

 Times Cited Count:11 Percentile:59.58(Physics, Nuclear)

no abstracts in English

Journal Articles

Investigation of the Factor of Failed Steam Jet in the Acid Recovery Process of Tokai Reprocessing Plant

Shirozu, Hidetomo; Shimizu, Ryo; Takaya, Akikazu; Uchida, Naoki; Tanaka, Kosuke; Yamaguchi, Akira; Aoto, Kazumi

Saikuru Kiko Giho, (21), p.41 - 55, 2003/00

The cause of the failure, which had occurred in the steam jet (273J202) in the acid recovery process of Tokai reprocessing plant, was investigated.

Oral presentation

Development of compact laser optics for an in-situ spin-exchange optical pumping $$^3$$He neutron spin filter

Oku, Takayuki; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Shinohara, Takenao; Sakaguchi, Yoshifumi*; Ino, Takashi*; Oyama, Kenji*; Chang, L.-J.*; et al.

no journal, , 

We have been developing a $$^3$$He neutron spin filter (NSF) for the efficient utilization of pulsed neutrons, since it can polarize neutrons effectively in a wide energy range. The $$^3$$He NSF is effective even for neutrons with energy higher than several-tens-meV, so that it will be useful for the study of high-energy magnetic excitation. Since the $$^3$$He NSF can also cover a large solid angle and polarize neutrons without deflecting them from their original course, it is suitable for the analyzer for SANS instruments and reflectometers. In addition, the $$^3$$He NSF will be a key device in the application of recently developed magnetic field imaging technique by using polarized pulsed neutrons. In order to apply the $$^3$$He NSF to experiments at a pulsed neutron experimental facility such as the J-PARC, it is important to make the system stable and easy to setup and operate, because the system is located inside a radiation shield for high energy $$gamma$$ ray and neutrons. In this study, we have developed compact laser optics with a volume holographic grating element for a spin-exchange optical pumping (SEOP) system, and composed an in-situ SEOP $$^3$$He NSF.

Oral presentation

SCC susceptibility of carbon steel in simulated anaerobic alkaline ground-water environments

Shimizu, Kosuke*; Inoue, Hiroyuki*; Taniguchi, Naoki; Sakamaki, Keiko; Tachikawa, Hirokazu*

no journal, , 

The effect of solution pH to the SCC susceptibility of carbon-steel (CS) in an anaerobic ground water must be investigated to guarantees the soundness of the CS HLW overpack for ultra-long term. For the present study, the SCC susceptibility of CS at and near the reversible hydrogen evolution potentials at each solution pH was evaluated by the slow strain rate test (SSRT); as for the test solution, NaHCO$$_{3}$$/Na$$_{2}$$CO$$_{3}$$ solutions whose pH were adjusted 8 to 13 and purged with Ar gas were used. The SCC susceptibility became minimum at pH near 9 and 13 as well as reached maximum at pH near 11.

Oral presentation

Development of compact laser optics for an in-situ spin-exchange optical pumping $$^3$$He neutron spin filter

Oku, Takayuki; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Shinohara, Takenao; Sakaguchi, Yoshifumi*; Ino, Takashi*; Oyama, Kenji*; Chang, L.-J.*; et al.

no journal, , 

The $$^3$$He NSF is effective even for neutrons with energy higher than several-tens-meV, so that it will be useful for the study of high-energy magnetic excitation. Since the $$^3$$He NSF can also cover a large solid angle and polarize neutrons without deflecting them from their original course, it is suitable for the analyzer for SANS instruments and reflectometers. In order to apply the $$^3$$He NSF to experiments at a pulsed neutron experimental facility such as the J-PARC, it is important to make the system stable and easy to setup and operate, because the system is located inside a radiation shield for high energy $$gamma$$ ray and neutrons. In this study, we have developed compact laser optics with a volume holographic grating (VHG) element for a spin-exchange optical pumping (SEOP) system, and composed an in-situ SEOP $$^3$$He NSF. The design and performance of the in-situ SEOP $$^3$$He NSF will be then presented, and its possible application will be discussed.

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

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

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

Assessment of chromosome translocation in wild Japanese macaques in Fukushima

Fujishima, Yohei*; Suzuki, Masatoshi*; Goh, V. S. T.*; Ariyoshi, Kentaro*; Kasai, Kosuke*; Nakata, Akifumi*; Kino, Yasushi*; Oka, Toshitaka; Shinoda, Hisashi*; Shimizu, Yoshinaka*; et al.

no journal, , 

After the Fukushima Daiichi Nuclear Power Plant accident, the surrounding environment was contaminated with radionuclides. Although the ambient dose rates are decreasing, prolonged effects of chronic low-dose exposure on animals are expected to be seen in the coming years. It is necessary to assess the effects of radioactivity on the wild animals in this area to better understand about the risk of low dose radiation. The chromosome translocation frequency of Japanese macaques were significantly higher in Fukushima groups comparing from control groups in Miyagi. Furthermore, chromosome translocation frequencies tended to correlate between external doses or internal dose-rates. However, chromosome translocation frequency was decreasing year by year, which may reflect restoration of environments such as decreasing of ambient dose-rates and decontamination efforts.

18 (Records 1-18 displayed on this page)
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