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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

Journal Articles

Kinetic inductance neutron detector operated at near critical temperature

Vu, TheDang; Nishimura, Kazuma*; Shishido, Hiroaki*; Harada, Masahide; Oikawa, Kenichi; Miyajima, Shigeyuki*; Hidaka, Mutsuo*; Oku, Takayuki; Soyama, Kazuhiko; Aizawa, Kazuya; et al.

Journal of Physics; Conference Series, 1590, p.012036_1 - 012036_9, 2020/07

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 (Internet), 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

Temperature dependent characteristics of neutron signals from a current-biased Nb nanowire detector with $$^{10}$$B converter

Vu, TheDang; Iizawa, Yuki*; Nishimura, Kazuma*; Shishido, Hiroaki*; Kojima, Kenji*; Oikawa, Kenichi; Harada, Masahide; Miyajima, Shigeyuki*; Hidaka, Mutsuo*; Oku, Takayuki; et al.

Journal of Physics; Conference Series, 1293, p.012051_1 - 012051_9, 2019/10

Journal Articles

Gamma-ray glow preceding downward terrestrial gamma-ray flash

Wada, Yuki*; Enoto, Teruaki*; Nakamura, Yoshitaka*; Furuta, Yoshihiro; Yuasa, Takayuki*; Nakazawa, Kazuhiro*; Morimoto, Takeshi*; Sato, Mitsuteru*; Matsumoto, Takahiro*; Yonetoku, Daisuke*; et al.

Communications Physics (Internet), 2(1), p.67_1 - 67_9, 2019/06

 Times Cited Count:3 Percentile:25.77(Physics, Multidisciplinary)

Journal Articles

Cryogenic sample environments shared at the MLF, J-PARC

Kawamura, Seiko; Takahashi, Ryuta*; Ishikado, Motoyuki*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ouchi, Keiichi*; Kira, Hiroshi*; Kambara, Wataru*; Aoyama, Kazuhiro*; Sakaguchi, Yoshifumi*; et al.

Journal of Neutron Research, 21(1-2), p.17 - 22, 2019/05

The Cryogenics and Magnets group in the Sample Environment team is responsible for operation of cryostats and magnets for user's experiments at the MLF in J-PARC. We have introduced a top-loading $$^4$$He cryostat, a bottom-loading $$^3$$He cryostat, a dilution refrigerator insert and a superconducting magnet. The frequency of use of them dramatically becomes higher in these two years, as the beam power and the number of proposal increase. To respond such situation, we have made efforts to enhance performance of these equipment as follows. The $$^3$$He cryostat originally involves an operation software for automatic initial cooling down to the base temperature and automatic re-charge of $$^3$$He. Recently we made an additional program for automatic temperature control with only the sorb heater. Last year, a new outer vacuum chamber of the magnet with an oscillating radial collimator (ORC) was fabricated. The data quality was drastically improved by introducing this ORC so that the magnet can be used even for the inelastic neutron scattering experiments.

Journal Articles

Highlight of recent sample environment at J-PARC MLF

Kawamura, Seiko; Hattori, Takanori; Harjo, S.; Ikeda, Kazutaka*; Miyata, Noboru*; Miyazaki, Tsukasa*; Aoki, Hiroyuki; Watanabe, Masao; Sakaguchi, Yoshifumi*; Oku, Takayuki

Neutron News, 30(1), p.11 - 13, 2019/05

In Japanese neutron scattering facilities, some SE equipment that are frequently used at an instrument, such as the closed-cycle refrigerator (CCR), have been prepared for the instrument as standard SE. They are operated for user experiments by the instrument group. The advantage of this practice is that they can optimize the design of the SE for the instrument and can directly respond to users' requests. On the other hand, the SE team in the Materials and Life Science Experimental Facility (MLF) in J-PARC has managed commonly used SE to allow neutron experiments with more advanced SE. In this report, recent SE in the MLF is introduced. Highlighted are the SE in BL11, BL19, BL21 and BL17 and other SE recently progressed by the SE team.

Journal Articles

Polarized neutrons

Hiraka, Haruhiro*; Yamaguchi, Yasuo*; Maruyama, Ryuji; Oku, Takayuki; Ino, Takashi*

Hamon, 28(3), p.144 - 149, 2018/08

no abstracts in English

Journal Articles

Sample environment at the J-PARC MLF

Kawamura, Seiko; Oku, Takayuki; Watanabe, Masao; Takahashi, Ryuta; Munakata, Koji*; Takata, Shinichi; Sakaguchi, Yoshifumi*; Ishikado, Motoyuki*; Ouchi, Keiichi*; Hattori, Takanori; et al.

Journal of Neutron Research, 19(1-2), p.15 - 22, 2017/11

Sample environment (SE) team at the Materials and Life Science Experimental Facility (MLF) in J-PARC has worked on development and operation of SE equipment and devices. All the members belong to one sub-team at least, such as Cryogenic and magnet, High temperature, High pressure, Soft matter and special environment including Pulse magnet, Hydrogen environment, Light irradiation and $$^3$$He spin filter. Cryostats, a magnet, furnaces, a VX-6-type Paris-Edinburgh press and a prototype of a Spin-Exchange Optical Pumping (SEOP) based $$^3$$He spin filter for polarized neutron beam experiments are in operation. Furthermore, a prototype of compact power supply for a pulsed magnet system is currently developed. In the J-PARC Research Building, several pieces of equipment for softmatter research such as a rheometer and a gas and vapor adsorption measurement instrument have been prepared.

Journal Articles

Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex, 3; Neutron devices and computational and sample environments

Sakasai, Kaoru; Sato, Setsuo*; Seya, Tomohiro*; Nakamura, Tatsuya; To, Kentaro; Yamagishi, Hideshi*; Soyama, Kazuhiko; Yamazaki, Dai; Maruyama, Ryuji; Oku, Takayuki; et al.

Quantum Beam Science (Internet), 1(2), p.10_1 - 10_35, 2017/09

Neutron devices such as neutron detectors, optical devices including supermirror devices and $$^{3}$$He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.

Journal Articles

Neutron flux spectrum revealed by Nb-based current-biased kinetic inductance detector with a $$^{10}$$B conversion layer

Miyajima, Shigeyuki*; Shishido, Hiroaki*; Narukami, Yoshito*; Yoshioka, Naohito*; Fujimaki, Akira*; Hidaka, Mutsuo*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Arai, Masatoshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 842, p.71 - 75, 2017/01

 Times Cited Count:8 Percentile:14.05(Instruments & Instrumentation)

JAEA Reports

Proceedings of the 21st Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-XXI); Sep. 29 - Oct.3, 2014, Ibaraki Prefectural Center, Mito, Japan

Oku, Takayuki; Nakamura, Mitsutaka; Sakai, Kenji; Teshigawara, Makoto; Hideki, Tatsumoto*; Yonemura, Masao*; Suzuki, Junichi*; Arai, Masatoshi*

JAEA-Conf 2015-002, 660 Pages, 2016/02

JAEA-Conf-2015-002.pdf:168.34MB

The twenty first meeting of the International Collaboration on Advanced Neutron Source (ICANS-XXI) was held at Ibaraki Prefectural Culture Center in Mito from 29 September to 3 October 2014. It was hosted by Japan Atomic Energy Agency (JAEA), High Energy Accelerator Research Organization (KEK) and Comprehensive Research Organization for Science and Society (CROSS). In the meeting, new science and technology in the new era with the high power neuron sources were discussed in mostly "workshop style" sessions. In each session, various kinds of issues related to not only the hardware, but also the software and even radiation safety were discussed with the keyword of "INTERFACE". More than 200 Papers were presented in the meeting and 72 contributed papers are compiled in the proceedings.

Journal Articles

Development status of the NMR system for the polarized $$^{3}$$He Neutron Spin Filter (NSF) in the MLF at J-PARC

Sakai, Kenji; Oku, Takayuki; Hayashida, Hirotoshi*; Kira, Hiroshi*; Hiroi, Kosuke; Ino, Takashi*; Oyama, Kenji*; Okawara, Manabu*; Kakurai, Kazuhisa; Shinohara, Takenao; et al.

JPS Conference Proceedings (Internet), 8, p.036015_1 - 036015_6, 2015/09

The polarized $$^{3}$$He filter, which polarizes neutrons due to a large neutron absorption cross section of $$^{3}$$He with strong spin selectivity, becomes a convenient neutron spin filter (NSF) because it is operated immediately after its installation in beam lines without any neutron beam adjustments. For realizing such the NSF, a nuclear magnetic resonance (NMR) system is indispensable for monitoring $$^{3}$$He nuclear spin polarization ${it P}$ of the NSF. We have developed the flexible NMR system based on adiabatic fast passage (AFP) and pulse NMR methods by using their complementary features. In comparing with the values of ${it P}$ obtained by neutron transmission measurement at the beam line 10 of the J-PARC, we measured the correlations between the AFP and pulse NMR signals as changing condition of temperature, amplitude and applying period of the radio frequency field for the pulse NMR, and so on. As the results, we confirmed that our system would function enough as the ${it P}$ monitor.

Journal Articles

Operation and maintenance experience from the HTTR database

Shimizu, Atsushi; Furusawa, Takayuki; Homma, Fumitaka; Inoi, Hiroyuki; Umeda, Masayuki; Kondo, Masaaki; Isozaki, Minoru; Fujimoto, Nozomu; Iyoku, Tatsuo

Journal of Nuclear Science and Technology, 51(11-12), p.1444 - 1451, 2014/11

 Times Cited Count:1 Percentile:87.72(Nuclear Science & Technology)

JAEA has kept up a data-base system of operation and maintenance experiences of the HTTR. The objective of this system is to share the information obtained operation and maintenance experiences and to make use of lessons learned and knowledge into a design, construction and operation managements of the future HTGR. More than one thousand records have been registered into the system between 1997 and 2012. This paper describes the status of the data-base system, and provides suggestions for improvement from four experiences: (1) performance degradation of helium compressors; (2) malfunction of reserved shutdown system in reactivity control system; (3) maintenance experiences of emergency gas turbine generators; and (4) experiences of the Great East Japan Earthquake. These experiences are extracted from the system as important lessons learned to be expected to apply for design, construction and operation managements of future HTGR.

Journal Articles

Development of portable polarized $$^{3}$$He neutron spin filter and its application to magnetic field imaging at J-PARC

Sakai, Kenji; Oku, Takayuki; Hayashida, Hirotoshi; Kira, Hiroshi*; Shinohara, Takenao; Oikawa, Kenichi; Harada, Masahide; Kakurai, Kazuhisa; Aizawa, Kazuya; Arai, Masatoshi; et al.

Journal of Physics; Conference Series, 528, p.012016_1 - 012016_7, 2014/07

 Times Cited Count:0 Percentile:100

In polarized neutron experiments, it is interested in expanding measurable neutron energy region up to epithermal neutrons. For realizing this situation, a Polarized $$^{3}$$He Spin Flipper (PHSF) has a key role because it can polarize from cold to epithermal neutrons, and flip neutron spins by flipping the $$^{3}$$He nuclear spin direction. We have developed the portable PHSF consisting of a cylindrical glass cell filled with $$^{3}$$He gas which is installed a solenoid coil of 20 cm in diameter and 30 cm long. After polarizing the $$^{3}$$He gas by irradiating a laser light based on a SEOP technique, the PHSF is brought by hands to experimental areas with kept its polarization. We carried out the feasibility test on our portable PHSF in the MLF of J-PARC and demonstrated it worked well by evaluating flipping ratios of polarized neutrons and attempting to visualize magnetic fields generated by sample coils.

Journal Articles

Development of polarized Xe gas target for neutron experiment at J-PARC

Sakai, Kenji; Oku, Takayuki; Shinohara, Takenao; Kira, Hiroshi; Oi, Motoki; Maekawa, Fujio; Kakurai, Kazuhisa; Ino, Takashi*; Arimoto, Yasushi*; Shimizu, Hirohiko*; et al.

Journal of Physics; Conference Series, 340, p.012037_1 - 012037_7, 2012/02

 Times Cited Count:2 Percentile:33.74

At the Materials and Life science experimental Facility (MLF) in J-PARC, an experiment of detecting a neutron polarizing ability caused by a neutron-nuclear (n-N) spin correlation term at a resonant peak of $$^{129}$$Xe is planned. The Xe gas having a high polarization under low magnetic field and room temperature by a spin exchange optical pumping (SEOP) technique is expected to become a suitable target for verification of the neutron optical theorem (NOPT). We evaluated measurable quantities based on the NOPT, developed a polarized Xe gas system, and carried out a feasibility test of our apparatus. This paper reports on the present status of the experiment.

Journal Articles

Quantitative magnetic field imaging by polarized pulsed neutrons at J-PARC

Shinohara, Takenao; Sakai, Kenji; Oi, Motoki; Kai, Tetsuya; Harada, Masahide; Oikawa, Kenichi; Maekawa, Fujio; Suzuki, Junichi; Oku, Takayuki; Takata, Shinichi; et al.

Nuclear Instruments and Methods in Physics Research A, 651(1), p.121 - 125, 2011/09

 Times Cited Count:24 Percentile:9.48(Instruments & Instrumentation)

no abstracts in English

Journal Articles

Developments of in-situ SEOP polarized $$^{3}$$He neutron spin filter in Japan

Kira, Hiroshi; Sakaguchi, Yoshifumi; Oku, Takayuki; Suzuki, Junichi; Nakamura, Mitsutaka; Arai, Masatoshi; Endo, Yasuo; Chang, L.-J.; Kakurai, Kazuhisa; Arimoto, Yasushi*; et al.

Journal of Physics; Conference Series, 294, p.012014_1 - 012014_5, 2011/06

 Times Cited Count:9 Percentile:5

Journal Articles

Applications of $$^{3}$$He neutron spin filters on the small-angle neutron scattering spectrometer SANS-J-II

Sakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Aizawa, Kazuya; Arai, Masatoshi; Noda, Yohei; et al.

Journal of Physics; Conference Series, 294(1), p.012017_1 - 012017_7, 2011/06

 Times Cited Count:2 Percentile:29.56

154 (Records 1-20 displayed on this page)