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Journal Articles

Negative muonium ion production with a C12A7 electride film

Otani, Masashi*; Fukao, Yoshinori*; Futatsukawa, Kenta*; Kawamura, Naritoshi*; Matoba, Shiro*; Mibe, Tsutomu*; Miyake, Yasuhiro*; Shimomura, Koichiro*; Yamazaki, Takayuki*; Hasegawa, Kazuo; et al.

Journal of Physics; Conference Series, 1350, p.012067_1 - 012067_6, 2019/12

 Times Cited Count:0 Percentile:100

Negative muonium atom ($$mu^+$$e$$^-$$e$$^-$$, Mu$$^-$$) has unique features stimulating potential interesting for several scientific fields. Since its discovery in late 1980's in vacuum, it has been discussed that the production efficiency would be improved using a low-work function material. C12A7 was a well-known insulator as a constituent of alumina cement, but was recently confirmed to exhibit electric conductivity by electron doping. The C12A7 electride has relatively low-work function (2.9 eV). In this paper, the negative muonium production measurement with several materials including a C12A7 electride film will be presented. Measured production rate of the Mu$$^-$$ were 10$$^{-3}$$/s for all the Al, electride, and SUS target. Significant enhancement on electride target was not observed, thus it is presumed that the surface condition should be more carefully treated. There was no material dependence of the Mu$$^-$$ averaged energy: it was 0.2$$pm$$0.1keV.

Journal Articles

Beam commissioning of muon beamline using negative hydrogen ions generated by ultraviolet light

Nakazawa, Yuga*; Bae, S.*; Choi, H.*; Choi, S.*; Iijima, Toru*; Iinuma, Hiromi*; Kawamura, Naritoshi*; Kitamura, Ryo; Kim, B.*; Ko, H. S.*; et al.

Nuclear Instruments and Methods in Physics Research A, 937, p.164 - 167, 2019/09

 Times Cited Count:1 Percentile:53.3(Instruments & Instrumentation)

A muon linac is under development for the precise measurement of the muon anomalous magnetic moment ($$g$$-2) and electric dipole moment (EDM) with a reaccelerated thermal muon beam. An H$$^-$$ source driven by an ultraviolet light has been developed for the muon acceleration experiment. Prior to the acceleration experiment, a beamline commissioning was performed using this H$$^-$$ beam, since the accelerated muon intensity is very low. We successfully measured the magnetic rigidity, which is essential for identifying the accelerated muons. This H$$^-$$ source is capable of utilizing as a general-purpose beam source for other beamline.

Journal Articles

Introduction and implementation of physical protection measures including trustworthiness program at Tokai Reprocessing Facilities

Nakamura, Hironobu; Kimura, Takashi; Yamazaki, Katsuyuki; Kitao, Takahiko; Tasaki, Takashi; Iida, Toru

Proceedings of International Conference on Physical Protection of Nuclear Material and Nuclear Facilities (Internet), 9 Pages, 2018/09

After the accident of Fukushima Daiichi Nuclear Power Station, to develop effective security measures based on the lesson learned from such crisis and to meet the IAEA Nuclear Security Recommendations (INFCIRC/225/Rev.5), NRA in Japan made a partial amendment of the regulations concerning the reprocessing activity in 2012. The Tokai reprocessing facility implemented all of those security measures by the end of March 2014. Those new measures help us to keep high degree of security level and contributed to our planned operations to reduce the potential risk of the plant. On the other hand, the trustworthiness program was newly introduced in 2016, based on the trustworthiness policy determined by NRA. The implementing entity of the program is JAEA for the Tokai Reprocessing Facility and is required for both the persons afford unescorted access to Category I and II, CAS/SAS, and the persons afford access to the sensitive information. Those who are involved this program will be judged before engaging the work whether they might act as insider to cause or assist radiological sabotage or unauthorized removal of nuclear material, or leak sensitive information. The program is expected as a measure against insider at reprocessing facilities, and is expected to be enforced around the autumn of 2017. As well as the establishment of security measures, the promoting nuclear security culture for all employees was a big challenge. The Tokai reprocessing facility have introduced several security culture activities, such as case study education of security events done by a small group and putting up the security culture poster and so on. This paper presents introduction and implementation with effectiveness of security measures in the Tokai reprocessing facilities and the future security measures applied to the reprocessing facilities are discussed.

Journal Articles

First muon acceleration using a radio-frequency accelerator

Bae, S.*; Choi, H.*; Choi, S.*; Fukao, Yoshinori*; Futatsukawa, Kenta*; Hasegawa, Kazuo; Iijima, Toru*; Iinuma, Hiromi*; Ishida, Katsuhiko*; Kawamura, Naritoshi*; et al.

Physical Review Accelerators and Beams (Internet), 21(5), p.050101_1 - 050101_6, 2018/05

 Times Cited Count:9 Percentile:13.16(Physics, Nuclear)

Muons have been accelerated by using a radio-frequency accelerator for the first time. Negative muonium atoms (Mu$$^{-}$$), which are bound states of positive muons and two electrons, are generated from through the electron capture process in an aluminum degrader. The generated Mu$$^{-}$$'s are initially electrostatically accelerated and injected into a radio-frequency quadrupole linac (RFQ). In the RFQ, the Mu$$^{-}$$'s are accelerated to 89 keV. The accelerated Mu$$^{-}$$'s are identified by momentum measurement and time of flight. This compact muon linac opens the door to various muon accelerator applications including particle physics measurements and the construction of a transmission muon microscope.

Journal Articles

Thermal desorption characteristics of several charge stripper carbon films for J-PARC RCS

Kamiya, Junichiro; Kinsho, Michikazu; Yamazaki, Yoshio; Yoshimoto, Masahiro; Yanagibashi, Toru*

Journal of the Vacuum Society of Japan, 60(12), p.484 - 489, 2017/12

Multi-turn H$$^{-}$$ charge exchange injection is employed as a beam injection method in the 3-GeV RCS (Rapid cycling synchrotron) at J-PARC (Japan Proton Accelerator Research Complex). In this method, injection H$$^{-}$$ beam is put on the same orbit as already circulating proton (H$$^{+}$$) beam in a dipole magnetic field due to the opposite curvature of the injected and circulating beams. In the straight section, where the two beams coincide with each other, both beams are passed through a thin foil, which strips two weakly bound electrons off each H$$^{-}$$ ion, forming an intense beam of protons. The thin foil, which is mostly made of carbon, would be the source of the outgassing, especially when its temperature rises due to the beam hitting. Therefore it is important to estimate the amount and components of the outgassing from the charge stripping foil. In this paper, we will report the thermal desorption measurement results for the several foil, which is used as the charge stripping foil in the RCS.

Journal Articles

Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.

Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12

The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.

JAEA Reports

Handbook of advanced nuclear hydrogen safety (1st Edition)

Hino, Ryutaro; Takegami, Hiroaki; Yamazaki, Yukie; Ogawa, Toru

JAEA-Review 2016-038, 294 Pages, 2017/03

JAEA-Review-2016-038.pdf:11.08MB

In the aftermath of the Fukushima nuclear accident, safety measures against hydrogen in severe accident have been recognized as a serious technical problem in Japan. Therefore, efforts have begun to form a common knowledge base between nuclear engineers and experts on combustion and explosion, and to secure and improve future nuclear energy safety. As one of such activities, we have prepared the "Handbook of Advanced Nuclear Hydrogen Safety" under the Advanced Nuclear Hydrogen Safety Research Program funded by the Agency for Natural Resources and Energy of the Ministry of Economy, Trade and Industry. The concepts of the handbook are as follows: to show advanced nuclear hydrogen safety technologies that nuclear engineers should understand, to show hydrogen safety points to make combustion-explosion experts cooperate with nuclear engineers, to expand information on water radiolysis considering the situation from just after the Fukushima accidents and to the waste management necessary for decommissioning after the accident, etc.

Journal Articles

Evaluation of the cryogenic tensile properties for aramid fiber rod

Saito, Toru; Okubo, Toshikazu*; Izumi, Keisuke*; Okawa, Yoshinao*; Kobayashi, Norihiro*; Yamazaki, Toru; Kawano, Katsumi; Isono, Takaaki

Teion Kogaku, 50(8), p.400 - 408, 2015/08

Aramid fiber-reinforced plastic (AFRP) has been developed as a structural material that has the advantages of light weight and high strength. In this study, tensile tests were carried out to measure the tensile properties of AFRP rod on the market for reinforcement of concrete at room temperature, 77 K and 4.2 K. Especially at cryogenic temperatures, it is difficult to perform a tensile test of the bar because the specimen slips through the jig grip. To prevent the rod from slipping, tensile tests were carried out with some filling conditions. The applicable and appropriate tensile test conditions were established by modifying the jig grip, treating the surface of the rod and using cryogenic epoxy infill to grip the rod. They were more than 1100 MPa. Additionally, the AFRP rod included a temperature dependence in which the Young's modulus increased as the test temperature decreased. It was confirmed that the Young's modulus increased because aramid fiber was more dominant than epoxy.

Journal Articles

Effect of change of aging heat treatment pattern on the JK2LB jacket for the ITER central solenoid

Ozeki, Hidemasa; Saito, Toru; Kawano, Katsumi; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Yamazaki, Toru; Isono, Takaaki

Physics Procedia, 67, p.1010 - 1015, 2015/07

 Times Cited Count:0 Percentile:100

Journal Articles

Mechanical properties of high manganese austenitic stainless steel JK2LB for ITER central solenoid jacket material

Saito, Toru; Kawano, Katsumi; Yamazaki, Toru; Ozeki, Hidemasa; Isono, Takaaki; Hamada, Kazuya*; Devred, A.*; Vostner, A.*

Physics Procedia, 67, p.1016 - 1021, 2015/07

 Times Cited Count:1 Percentile:45.02

Journal Articles

Atomic and electronic structures of Si(111)-$$sqrt{21}timessqrt{21}$$ superstructure

Fukaya, Yuki; Kubo, Keisuke*; Hirahara, Toru*; Yamazaki, Shiro*; Choi, W. H.*; Yeom, H. W.*; Kawasuso, Atsuo; Hasegawa, Shuji*; Matsuda, Iwao*

e-Journal of Surface Science and Nanotechnology (Internet), 10, p.310 - 314, 2012/07

no abstracts in English

Journal Articles

Atomic structure of two-dimensional binary surface alloys; Si(111)-$$sqrt{21}timessqrt{21}$$ superstructure

Fukaya, Yuki; Matsuda, Iwao*; Hashimoto, Mie*; Kubo, Keisuke*; Hirahara, Toru*; Yamazaki, Shiro*; Choi, W. H.*; Yeom, H. W.*; Hasegawa, Shuji*; Kawasuso, Atsuo; et al.

Surface Science, 606(11-12), p.919 - 923, 2012/06

 Times Cited Count:6 Percentile:66.91(Chemistry, Physical)

no abstracts in English

Journal Articles

Effect of Si interlayers on the magnetic and mechanical properties of Fe/Ge neutron polarizing multilayer mirrors

Maruyama, Ryuji; Yamazaki, Dai; Okayasu, Satoru; Takeda, Masayasu; Zettsu, Nobuyuki*; Nagano, Mikinori*; Yamamura, Kazuya*; Hayashida, Hirotoshi; Soyama, Kazuhiko

Journal of Applied Physics, 111(6), p.063904_1 - 063904_10, 2012/03

 Times Cited Count:3 Percentile:83.52(Physics, Applied)

no abstracts in English

Journal Articles

Demonstration of magnetic field imaging in a permalloy film with neutron spin phase contrast imaging

Hayashida, Hirotoshi; Yamazaki, Dai; Ebisawa, Toru*; Maruyama, Ryuji; Soyama, Kazuhiko; Tasaki, Seiji*; Hino, Masahiro*; Matsubayashi, Masahito

Nuclear Instruments and Methods in Physics Research A, 634(1, Suppl.), p.S90 - S93, 2011/04

 Times Cited Count:2 Percentile:77.62(Instruments & Instrumentation)

In a neutron spin interferometer (NSI), incident neutrons are in states of up- and down-spin eigenstates and a phase difference between the eigenstates is observed after transmission through a magnetic sample. Since the phase difference is proportional to an integral of magnetic field along a trajectory of neutrons, NSI imaging provides projection images of a distribution of magnetic field in the sample. We tried to visualize magnetic field in permalloy film with and without stress as a demonstration of the NSI imaging. An experiment was carried out at C3-1-2-2, MINE2 port at the neutron guide hall of JRR-3M with wavelength of 0.88nm and wavelength resolution of 0.3% in FWHM. Permalloy film with thickness of 0.1 mm was used as a sample and was stressed by bending with angles of 45 and 180 $$^{circ}$$. As a result, images of decrease of a saturated magnetization and an increase of leak magnetic field with increasing the bending angle were obtained.

Journal Articles

Quantitative evaluation of rice varieties in cadmium uptake activities for remediation of cadmium-contaminated soil

Ishikawa, Satoru*; Suzui, Nobuo; Ito, Sayuri*; Ishii, Satomi; Yamazaki, Haruaki*; Kawachi, Naoki; Ishioka, Noriko; Fujimaki, Shu

JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 102, 2011/01

Journal Articles

Electron compound nature in a surface atomic layer of a two-dimensional hexagonal lattice

Matsuda, Iwao*; Nakamura, Fumitaka*; Kubo, Keisuke*; Hirahara, Toru*; Yamazaki, Shiro*; Choi, W. H.*; Yeom, H. W.*; Narita, Hisashi*; Fukaya, Yuki; Hashimoto, Mie*; et al.

Physical Review B, 82(16), p.165330_1 - 165330_6, 2010/10

 Times Cited Count:9 Percentile:54.97(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

29th report of ITPA topical group meeting

Isayama, Akihiko; Sakakibara, Satoru*; Furukawa, Masaru*; Matsunaga, Go; Yamazaki, Kozo*; Watanabe, Kiyomasa*; Idomura, Yasuhiro; Sakamoto, Yoshiteru; Tanaka, Kenji*; Tamura, Naoki*; et al.

Purazuma, Kaku Yugo Gakkai-Shi, 86(6), p.374 - 377, 2010/06

no abstracts in English

Journal Articles

27th report of ITPA topical group meeting

Osakabe, Masaki*; Shinohara, Koji; Toi, Kazuo*; Todo, Yasushi*; Hamamatsu, Kiyotaka; Murakami, Sadayoshi*; Yamamoto, Satoshi*; Idomura, Yasuhiro; Sakamoto, Yoshiteru; Tanaka, Kenji*; et al.

Purazuma, Kaku Yugo Gakkai-Shi, 85(12), p.839 - 842, 2009/12

no abstracts in English

Journal Articles

A Beam divergence correction mirror for neutron resonance spin echo

Maruyama, Ryuji; Hino, Masahiro*; Hayashida, Hirotoshi; Kitaguchi, Masaaki*; Achiwa, Norio*; Yamazaki, Dai; Ebisawa, Toru*; Soyama, Kazuhiko

Physica B; Condensed Matter, 404(17), p.2594 - 2599, 2009/09

 Times Cited Count:3 Percentile:81.17(Physics, Condensed Matter)

Neutron resonance spin echo (NRSE) is one of the most useful techniques for quasi-elastic scattering with high energy resolution. The path length variation due to the beam divergence has to be corrected in high resolution NRSE measurement because it gives the limit in the energy resolution. A neutron focusing technique using neutron supermirrors is effective to overcome this problem. When a cylindrical shaped neutron supermirror placed in the center of the flight path with a pair of RSFs has the object and the image plane corresponding to the each coil plane of the first and the second RSF, the path length difference can be corrected for the neutron beam with large divergent angle, which leads to the realization of high intensity as well as high resolution in NRSE measurement. In this study, the correction method of the beam divergence with a cylindrical shaped supermirror and its experimental results are discussed.

Journal Articles

Effect of interfacial roughness correlation on diffuse scattering intensity in a neutron supermirror

Maruyama, Ryuji; Yamazaki, Dai; Ebisawa, Toru*; Soyama, Kazuhiko

Journal of Applied Physics, 105(8), p.083527_1 - 083527_8, 2009/04

 Times Cited Count:17 Percentile:39.65(Physics, Applied)

Neutron supermirrors are one of the most useful multilayer devices in neutron experiments since a polychromatic neutron beam can be reflected. The diffuse intensity from a supermirror has to be suppressed since it causes a serious problem of low signal to background noise in focusing systems. The diffuse intensity can be decreased by more than an order of magnitude by adopting NiC/Ti multilayers instead of conventional Ni/Ti multilayers, which leads to a high performance focusing system with a diffuse intensity down to the order of 10$$^{-5}$$ of the specular intensity. In this study, in order to obtain the mechanism that controls the diffuse intensity from a supermirror, we investigated the crystal structure of Ni and NiC monolayers and the interface structure of Ni/Ti and NiC/Ti multilayers and demonstrated that a multilayer with a large vertical correlation length and a small lateral correlation length effectively suppresses the diffuse intensity from a supermirror.

72 (Records 1-20 displayed on this page)