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Iimoto, Takeshi*; Kinoshita, Norikazu*; Sakaguchi, Aya*; Sugihara, Shinji*; Takamiya, Koichi*; Tagami, Keiko*; Nagao, Seiya*; Bessho, Kotaro*; Matsumura, Hiroshi*; Miura, Taichi*; et al.
KEK Report 2016-3, 134 Pages, 2017/03
This report is summary of study on environmental radioactivity effected from the accident at the TEPCO Fukushima Daiichi Nuclear Power Plant in 5 years after the accident. It was compiled efforts related to the accident reported from the 13th to the 17th "Workshop on Environmental Radioactivity" which was held at the High Energy Accelerator Research and Development Organization.
Naito, Fujio*; Anami, Shozo*; Ikegami, Kiyoshi*; Uota, Masahiko*; Ouchi, Toshikatsu*; Onishi, Takahiro*; Oba, Toshiyuki*; Obina, Takashi*; Kawamura, Masato*; Kumada, Hiroaki*; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1244 - 1246, 2016/11
The proton linac installed in the Ibaraki Neutron Medical Research Center is used for production of the intense neutron flux for the Boron Neutron Capture Therapy (BNCT). The linac consists of the 3-MeV RFQ and the 8-MeV DTL. Design average beam current is 10mA. Target is made of Beryllium. First neutron production from the Beryllium target was observed at the end of 2015 with the low intensity beam as a demonstration. After the observation of neutron production, a lot of improvement s was carried out in order to increase the proton beam intensity for the real beam commissioning. The beam commissioning has been started on May 2016. The status of the commissioning is summarized in this report.
Nakashima, Hiroshi; Shibata, Tokushi; Nakane, Yoshihiro; Masukawa, Fumihiro; Matsuda, Norihiro; Iwamoto, Yosuke; Hirayama, Hideo*; Suzuki, Takenori*; Miura, Taichi*; Numajiri, Masaharu*; et al.
Proceedings of 14th Biennial Topical Meeting of the ANS Radiation Protection and Shielding Division (CD-ROM), p.267 - 282, 2006/00
no abstracts in English
Nakashima, Hiroshi; Nakane, Yoshihiro; Masukawa, Fumihiro; Matsuda, Norihiro; Oguri, Tomomi*; Nakano, Hideo*; Sasamoto, Nobuo*; Shibata, Tokushi*; Suzuki, Takenori*; Miura, Taichi*; et al.
Radiation Protection Dosimetry, 115(1-4), p.564 - 568, 2005/12
Times Cited Count：7 Percentile：51.6(Environmental Sciences)The High Intensity Proton Accelerator Project, named as J-PARC, is in progress, aiming at studies on the latest basic science and the advancing nuclear technology. In the project, the high-energy proton accelerator complex of the world highest intensity is under construction. In order to establish a reasonable shielding design, both simplified and detailed design methods were used in the shielding design of J-PARC. This paper reviews the present status of the radiation safety design study for J-PARC.
ssbauer isomer shifts of 
Cs-impurity atoms implanted into metallic matricesMuramatsu, Hisakazu*; Yoshikawa, K.*; *; *; Miura, Taichi*; Watanabe, Satoshi; Koizumi, Mitsuo; Osa, Akihiko; Sekine, Toshiaki
JAERI-Review 99-025, TIARA Annual Report 1998, p.211 - 213, 1999/10
no abstracts in English
Xe-implanted sources for the determination of the change of nuclear charge radius in the 81keV transition of Cs*; *; *; Miura, Taichi*; Koizumi, Mitsuo; Osa, Akihiko; Sekine, Toshiaki; *; *; *; et al.
Hyperfine Interactions (C), p.396 - 399, 1996/01
no abstracts in English
Nakashima, Hiroshi; Shibata, Tokushi; Sawahata, Kei; Miyamoto, Yukihiro; Nakane, Yoshihiro; Masukawa, Fumihiro; Seki, Kazunari; Sato, Koichi; Oguri, Tomomi*; Hirayama, Hideo*; et al.
no journal, ,
Aiming at studies on the latest basic science and the advancing nuclear technology, the J-PARC (Japan Proton Accelerator Research Complex) project is in progress, and the high-energy proton accelerator complex of the world highest intensity is under construction. Because of its very high beam power and its energy as well as the large-scale accelerator complex, we have encountered some difficult radiation problems in the radiation safety design. This paper reviews the radiation safety policy and methods for the design to overcome the problems on the radiation safety and the status of the radiation safety estimation for licensing of J-PARC.
Shibata, Tokushi; Nakashima, Hiroshi; Nakane, Yoshihiro; Masukawa, Fumihiro; Matsuda, Norihiro; Miura, Taichi*; Numajiri, Masaharu*; Suzuki, Takenori*; Takeuchi, Yasunori*
no journal, ,
J-PARC (Japan Proton Accelerator Research Complex) consists of a 400 MeV LINAC, a 3 GeV synchrotron, a 50 GeV synchrotron and three experimental halls for material and life science, hadron physics and neutrino physics. The radiation safety design for J-PARC is based on calculations on radiation outside the shielding, on the boundary of the controlled area and on the cite boundary. In order to study the accuracy of different methods and make clear the differences among different methods, some benchmark analyses on beam dump, bulk shielding, streaming and activation experiments were carried out. The activation of air, cooling water and the activation of soil and its effect to underground water have been also estimated. Since J-PARC is a complex accelerator facility, an interlock system is important for radiation safety. To prevent unintended radiation exposure, a carefully designed system was incorporated.
Ninomiya, Kazuhiko; Nakagaki, Reiko*; Kubo, Kenya*; Ishida, Katsuhiko*; Kobayashi, Yoshio*; Matsuzaki, Teiichiro*; Matsumura, Hiroshi*; Miura, Taichi*; Higemoto, Wataru; Shinohara, Atsushi*
no journal, ,
no abstracts in English
Ninomiya, Kazuhiko; Kita, Makoto*; Ito, Takashi; Nagatomo, Takashi*; Kubo, Kenya*; Shinohara, Atsushi*; Strasser, P.*; Kawamura, Naritoshi*; Shimomura, Koichiro*; Miyake, Yasuhiro*; et al.
no journal, ,
Muonic atom is an atom like system that has one negatively charged muon instead of an electron. It is known that the initial state of captured muon is influenced by the outer electron structure of muon capturing molecule and some muon capture models have been proposed. To investigate the molecular effect in muonic atom formation, we performed muon irradiation for low pressure NO and N
O gases and measured muonic X-rays emitted from muonic atoms. We found that the muon capture models are not reproduced our results.
Ninomiya, Kazuhiko; Ito, Takashi; Higemoto, Wataru; Kita, Makoto*; Shinohara, Atsushi*; Nagatomo, Takashi*; Kubo, Kenya*; Strasser, P.*; Kawamura, Naritoshi*; Shimomura, Koichiro*; et al.
no journal, ,
Muonic atom is an atom like system that has one negatively charged muon instead of an electron. It is known that the formation process of muonic atom is influenced by the structure of muon capturing molecule (molecular effect). In this study, we performed systematic muon irradiation for low pressure nitrogen oxide samples and discuss the molecular effect on muon capture phenomena.
Ninomiya, Kazuhiko; Ito, Takashi; Higemoto, Wataru; Kita, Makoto*; Shinohara, Atsushi*; Nagatomo, Takashi*; Kubo, Kenya*; Strasser, P.*; Kawamura, Naritoshi*; Shimomura, Koichiro*; et al.
no journal, ,
A muonic atom is an atomic system that contains one negatively charged muon (muon is one of elementally particles) instead of an electron. When a muon is injected in material, the muon is slowing down by collisions with atomic electrons, and then low energy muon is captured on the coulomb field of a nucleus. As a result, the muon forms an atomic orbit around the nucleus, that is, a muonic atom is formed. It is considered that a muon capture phenomenon proceeds through muon collision and replacement with loosely binding electron, however the intrinsic mechanism of muon capture have not been investigated yet. In this study, we examine the formation processes of muonic atoms for nitrogen oxide samples (NO, NO and NO) by measuring muon characteristic X-rays (muonic X-rays) emitted after formation of muonic atoms.
Nakazawa, Takashi; Sato, Koichi; Miyamoto, Yukihiro; Nakashima, Hiroshi; Kasugai, Yoshimi; Kai, Tetsuya; Oi, Motoki; Miura, Taichi*; Takahashi, Kazutoshi*
no journal, ,
Radioactive nuclide activated in the mercury target of Materials and Life-Science Experimental Facility of J-PARC, the measurement results of the dose rate around the mercury target and the safety measures for radiation are reported.
Ninomiya, Kazuhiko; Ito, Takashi; Higemoto, Wataru; Strasser, P.*; Kawamura, Naritoshi*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Miura, Taichi*; Kita, Makoto*; Shinohara, Atsushi*; et al.
no journal, ,
A muonic atom is an atomic system that has one negatively charged muon instead of an electron. In this study, we examine the formation processes of muonic atoms for nitrogen oxide samples (NO, NO and NO) by measuring muon characteristic X-rays emitted after formation of muonic atoms, and the muon capture probabilities for these samples were determined. In the previous muon capture model, muon capture probability for each atom in molecule muonic atom is strongly influenced by the number of localized electrons in the atom. However, in our work, the experimental results were not reproduced by the previous model. In this paper, we discuss what influences on the muon capture probability.
Ninomiya, Kazuhiko; Ito, Takashi; Higemoto, Wataru; Strasser, P.*; Kawamura, Naritoshi*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Miura, Taichi*; Kita, Makoto*; Shinohara, Atsushi*; et al.
no journal, ,
A muonic atom is an atomic system that has one negatively charged muon instead of an electron. There are many studies related to the formation process of muonic atom by measuring muon characteristic X-rays. It is known that muon characteristic X-ray intensities are influenced by the density of the sample itself. However, most of previous studies did not consider this effect. In this study, we measured muon characteristic X-rays for dinitrogen mono-oxide with 0.1-1.0 atm. The same muonic X-ray intensities were obtained below 0.2 atm condition. This result means the density effect is neglectable below 0.2 atm for dinitrogen mono-oxide gas.
Ninomiya, Kazuhiko; Ito, Takashi; Higemoto, Wataru; Strasser, P.*; Kawamura, Naritoshi*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Miura, Taichi*; Kita, Makoto*; Shinohara, Atsushi*; et al.
no journal, ,
Muonic atom is an atomic system that has one negatively charged muon instead of an electron. Muonic atom is formed when a negative muon is stopped in matter. There are many studies of muonic atom formation by measuring muonic X-rays emitted after formation of muonic atom. From these studies, "molecular effect" on muonic atom formation becomes clear; different muonic X-ray structures are obtained from muon irradiations between allotropes. In addition, muonic X-ray intensity patterns are also influenced by density of muon irradiation sample (density effect). The quantitative examination of molecular and density effect is essential to investigate muonic atom formation process by measuring muonic X-rays. In this study, we investigated density effect of muonic X-ray structure for nitrogen oxide samples.
Ninomiya, Kazuhiko; Ito, Takashi; Higemoto, Wataru; Nagatomo, Takashi*; Strasser, P.*; Kawamura, Naritoshi*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Miura, Taichi; Kita, Makoto*; et al.
no journal, ,
We have been studying on the formation process of muonic atom by measuring muonic X-rays. It is known that muonic X-ray intensities are changed by the state of muon capturing atom. These intensities also influenced by the density of the sample itself. There are many studies to investigate muonic atom formation by measuring muonic X-ray intensities, however, the pressure dependence of muonic X-ray intensities have not been examined well. In this study, we investigate the pressure dependence of muonic X-ray intensities for NO, NO and NO samples below 1 bar pressure conditions.
Bessho, Kotaro*; Matsumura, Hiroshi*; Miura, Taichi*; Iimoto, Takeshi*; Kinoshita, Norikazu*; Sakaguchi, Aya*; Sugihara, Shinji*; Takamiya, Koichi*; Tagami, Keiko*; Nagao, Seiya*; et al.
no journal, ,
Workshop on Environmental Radioactivity was established in 2000 and has been held every year on February or March at KEK, Tsukuba. The proceedings with peer review has been published after every workshop. After the accident at the TEPCO Fukushima Daiichi Nuclear Power Plant occurred in 2011, large number of scientific reports related to the accident were presented in this workshop. Researchers, technicians, local government staff, and general citizens have participated in the workshop to exchange information on various subjects. The organizing members of the workshop summarized 326 reports in the workshop during 2012 to 2016 and related publications. The summary report was published as follows. KEK Report 2016-3 (ISBN978-4-9907232-9-3)
MnGa filmsSumida, Kazuki; Sakuraba, Yuya*; Masuda, Keisuke*; Kono, Takashi*; Kakoki, Masaaki*; Goto, Kazuki*; Zhou, W.*; Miyamoto, Koji*; Miura, Yoshio*; Okuda, Taichi*; et al.
no journal, ,
no abstracts in English
