Otani, Kyohei; Tsukada, Takashi; Ueno, Fumiyoshi; Kato, Chiaki
Zairyo To Kankyo, 69(9), p.246 - 252, 2020/09
The purpose of this study was to investigate the effect of artificial sea water concentration on the corrosion rate of carbon steel under air/solution alternating condition, and to clarify the corrosion mechanism of carbon steel that changes with artificial seawater concentration. Mass measurements showed that the corrosion rate of carbon steel in the alternating condition accelerates with increasing concentration in the concentration region between deionized water to 200 times diluted artificial seawater (ASW), and the corrosion rate decreases with increasing concentration in the concentration region between 20 times diluted ASW to undiluted ASW. It can be considered that the reason why the carbon steel corrosion was suppressed in highly concentrated artificial seawater would Mg ions and Ca ions in the artificial seawater precipitate and cover on the surface due to the increase in pH near the surface by oxygen reduction reaction.
Yamauchi, Hiroki; Sari, D. P.*; Watanabe, Isao*; Yasui, Yukio*; Chang, L.-J.*; Kondo, Keietsu; Ito, Takashi; Ishikado, Motoyuki*; Hagiwara, Masato*; Frontzek, M. D.*; et al.
Communications Materials (Internet), 1, p.43_1 - 43_6, 2020/07
High-temperature short-range order is discovered up to 720 K in MnRhSi by complementary use of neutron scattering and muon spin relaxation measurements.
Shinohara, Takenao; Kai, Tetsuya; Oikawa, Kenichi; Nakatani, Takeshi; Segawa, Mariko; Hiroi, Kosuke; Su, Y.; Oi, Motoki; Harada, Masahide; Iikura, Hiroshi; et al.
Review of Scientific Instruments, 91(4), p.043302_1 - 043302_20, 2020/04
Kondo, Yasuhiro; Hirano, Koichiro; Ito, Takashi; Kikuzawa, Nobuhiro; Kitamura, Ryo; Morishita, Takatoshi; Oguri, Hidetomo; Okoshi, Kiyonori; Shinozaki, Shinichi; Shinto, Katsuhiro; et al.
Journal of Physics; Conference Series, 1350, p.012077_1 - 012077_7, 2019/12
We have upgraded a 3-MeV linac at J-PARC. The ion source is same as the J-PARC linac's, and the old 30-mA RFQ is replaced by a spare 50-mA RFQ, therefore, the beam energy is 3 MeV and the nominal beam current is 50 mA. The main purpose of this system is to test the spare RFQ, but also used for testing of various components required in order to keep the stable operation of the J-PARC accelerator. The accelerator has been already commissioned, and measurement programs have been started. In this paper, present status of this 3-MeV linac is presented.
Otani, Masashi*; Futatsukawa, Kenta*; Mibe, Tsutomu*; Naito, Fujio*; Hasegawa, Kazuo; Ito, Takashi; Kitamura, Ryo; Kondo, Yasuhiro; Morishita, Takatoshi; Iinuma, Hiromi*; et al.
Journal of Physics; Conference Series, 1350, p.012097_1 - 012097_7, 2019/12
A disk and washer (DAW) coupled cavity linac (CCL) has been developed for a middle velocity part in a muon linac to measure muon anomalous magnetic moment and search for electric dipole moment. I will accelerate muons from = = 0.3 to 0.7 at an operational frequency of 1.3GHz. In this poster, the cavity design, beam dynamics design, and the cold-model measurements will be presented.
Kimura, Takashi; Tazaki, Makiko; Shimizu, Ryo; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.85 - 88, 2019/11
This is the summary of research result of methods for denuclearization and IAEA verification after the denuclearization in South Africa. South Africa had developed and possessed nuclear weapons, and dismantled them including the related facilities and equipment etc. by itself secretly in the past. The method for the denuclearization and the verification is unique in the world. This report could give us the lessons to investigate how to denuclearize and to verify them.
Tamai, Hiroshi; Shimizu, Ryo; Tazaki, Makiko; Kimura, Takashi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.89 - 92, 2019/11
Libya's denuclearisation, named 'the Libya model', is regarded as one of good practices in cooperation of the international community and measures that have a sense of speed with the countries and institutions involved. Success factors of the denuclearisation are the Libya's relatively low technological progress despite the procurement of extensive nuclear materials and components due to the delay of detecting the nuclear programme, prompt implementation with the close collaboration of countries concerned, and Libya's cooperation facing to the economic sanctions and the regime collapse by the Iraq war. Precious lessons will be learned towards the prevention and the denuclearisation in other countries.
Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.93 - 96, 2019/11
Iraq, defeated by the Gulf War, had to accept denuclearization under UN Security Council Resolution (UNSCR) 687, but did not immediately and accurately report all its past nuclear activities to the IAEA. IAEA, as an internationally authorized nuclear inspection and verification organization to Iraqi denuclearization by the UNSCR 687, gradually revealed existence and the whole picture of Iraqi clandestine nuclear activities and verified destruction of weapon related facilities and equipment as well as removal of nuclear materials outside Iraq. Analyzing Iraq's characteristics of denuclearization could serve as a good reference for not only preventing nuclear weapons development but also considering their denuclearization in current and future states.
Tazaki, Makiko; Kimura, Takashi; Shimizu, Ryo; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.81 - 84, 2019/11
South Africa had developed, manufactured, and possessed nuclear weapons, but later dismantled them all together with related facilities and equipment. After joining Treaty on the Non-Proliferation of Nuclear Weapons as a non-nuclear weapon state and concluding a Comprehensive Safeguards Agreement with the Atomic Energy Agency (IAEA), it started peaceful use of nuclear energy. In that sense, South Africa's denuclearization is one of good examples of past denuclearization in the world, although the South Africa's specific policy of apartheid had been deeply connected with its nuclear weapons development and denuclearization. Analysing South Africa's motivations for nuclear weapons development, incentives for denuclearization, and characteristics of its denuclearization could serve as a good reference for not only preventing nuclear weapons development but also considering their denuclearization in current and future states.
Shimizu, Ryo; Kimura, Takashi; Tazaki, Makiko; Nakatani, Takayoshi; Tamai, Hiroshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.97 - 99, 2019/11
Despite international accusations, Iran pursued uranium enrichment capacity. But through unprecedented strong economic sanctions, Iran accepted the restrictions on uranium enrichment capacity and agreed to accept the additional protocol. Nuclear program of Iran and nuclear deal are good precedents for denuclearization that has solved peacefully through multilateral negotiations, its process and lessons are compiled.
Otani, Kyohei; Tsukada, Takashi; Ueno, Fumiyoshi
Zairyo To Kankyo, 68(8), p.205 - 211, 2019/08
In the present study, the iron rust layer formed on the low ally steel in air-solution alternating condition was investigated by cross-sectional observation and analysis, and the mechanism of accelerated corrosion of the steel in the alternating condition was clarified. Observation and analysis showed that the multi-layered iron rust layer composed of red rust layer (FeOOH), rust crust layer (FeO), inner crystal (FeO), and inner rust layer was formed on the low alloy steel. It can be considered that the multi-layered iron rust layer accelerated the cathodic reaction rate of the steel in the alternating condition. This acceleration would be the reason why the corrosion rate of the low alloy steel in the alternating condition was accelerated.
Naoe, Takashi; Teshigawara, Makoto; Futakawa, Masatoshi; Mizutani, Haruki; Muramatsu, Toshiharu; Yamada, Tomonori; Ushitsuka, Yuji*; Tanaka, Nobuatsu*; Yamasaki, Kazuhiko*
Proceedings of 8th International Congress on Laser Advanced Materials Processing (LAMP 2019) (Internet), 5 Pages, 2019/05
Laser cutting is one of the options in the disposal of radio-active waste, such as spallation neutron target vessel in J-PARC, etc. Due to unique characteristic of laser, such as non-contact system, it is more easily to provide remote-controlled system in comparison with conventional one, such as mechanical cutting machine, etc. However, a demerit of laser cutting is the sputter and fume caused by laser cutting, resulting in contamination with radio-active materials its surroundings. Recently it was developed that the spatter suppression technique by controlling laser beam profile in laser welding process. In order to apply this suppression technique to laser cutting, first of all, we attempted to observe the phenomenon at melting area during laser cutting using a high-speed video camera in order to make the physical model. The result showed that the appearance of fume and sputter were independently confirmed in the time evolution.
Kataoka, Ryuho*; Nishiyama, Takanori*; Tanaka, Yoshimasa*; Kadokura, Akira*; Uchida, Herbert Akihito*; Ebihara, Yusuke*; Ejiri, Mitsumu*; Tomikawa, Yoshihiro*; Tsutsumi, Masaki*; Sato, Kaoru*; et al.
Earth, Planets and Space (Internet), 71, p.9_1 - 9_10, 2019/01
Transient ionization of the mesosphere was detected at around 65 km altitude during the isolated auroral expansion occurred at 2221-2226 UT on June 30, 2017. A general-purpose Monte Carlo particle transport code PHITS suggested that significant ionization is possible in the middle atmosphere due to auroral X-rays from the auroral electrons of 10 keV.
Torigoe, Shuhei*; Hattori, Takayuki*; Kodama, Katsuaki; Honda, Takashi*; Sagayama, Hajime*; Ikeda, Kazutaka*; Otomo, Toshiya*; Nitani, Hiroaki*; Abe, Hitoshi*; Murakawa, Hiroshi*; et al.
Physical Review B, 98(13), p.134443_1 - 134443_7, 2018/10
Nakatani, Yasuhiro*; Aratani, Hidekazu*; Fujiwara, Hidenori*; Mori, Takeo*; Tsuruta, Atsushi*; Tachibana, Shoichi*; Yamaguchi, Takashi*; Kiss, Takayuki*; Yamasaki, Atsushi*; Yasui, Akira*; et al.
Physical Review B, 97(11), p.115160_1 - 115160_7, 2018/03
Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11
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 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.
Ikushima, Kazuki*; Kitani, Yuji*; Shibahara, Masakazu*; Nishikawa, Satoru*; Furukawa, Takashi*; Akita, Koichi; Suzuki, Hiroshi; Morooka, Satoshi
Yosetsu Gakkai Rombunshu (Internet), 35(2), p.75s - 79s, 2017/06
Itoi, Hiroyuki*; Nishihara, Hirotomo*; Kobayashi, Shunsuke*; Ittisanronnachai, S.*; Ishii, Takafumi*; Berenguer, R.*; Ito, Masashi*; Matsumura, Daiju; Kyotani, Takashi*
Journal of Physical Chemistry C, 121(14), p.7892 - 7902, 2017/04
Nakatani, Yasuhiro*; Fujiwara, Hidenori*; Aratani, Hidekazu*; Mori, Takeo*; Tachibana, Shoichi*; Yamaguchi, Takashi*; Kiss, Takayuki*; Yamasaki, Atsushi*; Yasui, Akira*; Yamagami, Hiroshi*; et al.
Journal of Electron Spectroscopy and Related Phenomena, 220, p.50 - 53, 2017/01
We report the soft X-ray angle-resolved photoemission study for LaNiGe to reveal the electronic structures derived from non-4 bands of the heavy fermion compound CeNiGe. The photoemission spectra recorded at the La M absorption edges clearly show the enhancement of the La 5 components in the valence band spectra. The circular dichroism of photoemission spectra reveals the band-dependent dichroic response due to the orbital symmetry.