Spin-polarized Weyl cones and giant anomalous Nernst effect in ferromagnetic Heusler films

Sumida, Kazuki; Sakuraba, Yuya*; Masuda, Keisuke*; Kono, Takashi*; Kakoki, Masaaki*; Goto, Kazuki*; Zhou, W.*; Miyamoto, Koji*; Miura, Yoshio*; Okuda, Taichi*; et al.

Communications Materials (Internet), 1, p.89_1 - 89_9, 2020/11

https://doi.org/10.1038/s43246-020-00088-w

Negative muon capture ratios for nitrogen oxide molecules

Ninomiya, Kazuhiko*; Ito, Takashi; Higemoto, Wataru; Kawamura, Naritoshi*; Strasser, P.*; Nagatomo, Takashi*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Kita, Makoto*; Shinohara, Atsushi*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 319(3), p.767 - 773, 2019/03

https://doi.org/10.1007/s10967-018-6366-3

Beam commissioning of the linac for iBNCT

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

http://www.pasj.jp/web_publish/pasj2016/proceedings/PDF/TUP1/TUP118.pdf

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.

Radiation safety design for the J-PARC project

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

https://doi.org/10.1093/rpd/nci237

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.

Moessbauer and conversion-electron measurements of 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

Radiation safety aspects in J-PARC facility

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.

Investigation of initial state of captured muon by measuring muonic X-rays

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 NO gases and measured muonic X-rays emitted from muonic atoms. We found that the muon capture models are not reproduced our results.

Negative muon coulomb capture on nitrogen oxide molecules

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.

Molecular effect of muon capture phenomena on nitrogen oxide molecules

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.

Pressure dependence of muon cascading process for nitrogen oxide gas samples

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.