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Terada, Kentaro*; Sato, Akira*; Ninomiya, Kazuhiko*; Kawashima, Yoshitaka*; Shimomura, Koichiro*; Yoshida, Go*; Kawai, Yosuke*; Osawa, Takahito; Tachibana, Shogo*
Scientific Reports (Internet), 7(1), p.15478_1 - 15478_6, 2017/11
Times Cited Count:15 Percentile:63.95(Multidisciplinary Sciences)Electron- or X-ray-induced characteristic X-ray analysis has been widely used to determine chemical compositions of materials in vast research fields. In recent years, analysis of characteristic X-rays from muonic atoms, in which a muon is captured, has attracted attention because both a muon beam and a muon-induced characteristic X-ray have high transmission abilities. Here we report the first non-destructive elemental analysis of a carbonaceous chondrite using one of the world-leading intense direct current muon beam source (MuSIC; MUon Science Innovative Channel). We successfully detected characteristic muonic X-rays of Mg, Si, Fe, O, S and C from Jbilet Winselwan CM chondrite, of which carbon content is about 2 wt percent, and the obtained elemental abundance pattern was consistent with that of CM chondrites.
Yoshitomi, Hiroshi; Tatebe, Yosuke; Kawai, Keiichi; Kowatari, Munehiko
Progress in Nuclear Science and Technology (Internet), 4, p.81 - 84, 2014/04
The Facility of Radiation Standards of the Japan Atomic Energy Agency provides various radiation fields for calibration and testing. It is located about 120 km away from Fukushima Dai-ichi Nuclear Power Plant, and radioactive materials discharged by the Fukushima nuclear accident contaminated around the FRS, even inside the building including radiation controlled areas. One month after the accident, the maximum contamination level in the controlled areas was 3.8 Bq/cm. Cs, Cs, I, Te and I were detected by spectrometry using an HPGe detector. However, contamination in controlled areas under widely contaminated environment have not been discussed in detail. As for FRS, practices for reducing contamination in the controlled areas were necessary to avoid the influence of the contamination to the calibration works. These practices described that the following two approaches were effective: (1) decontamination of the controlled areas by wiping out with wet cloth or steam cleaners, and (2) to prevent the dust with radioactive materials from letting in the controlled areas. As a result, surface contaminates inside the controlled areas were reduced to be dozens of times lower as compared with outside.
Uchida, Kenichi*; Xiao, J.*; Adachi, Hiroto; Oe, Junichiro; Takahashi, Saburo; Ieda, Junichi; Ota, Takeru*; Kajiwara, Yosuke*; Umezawa, Hiromitsu*; Kawai, Hirotaka*; et al.
Nature Materials, 9(11), p.894 - 897, 2010/11
Times Cited Count:1023 Percentile:99.88(Chemistry, Physical)Thermoelectric generation is an essential function in future energy-saving technologies. However, it has so far been an exclusive feature of electric conductors, a situation which limits its application; conduction electrons are often problematic in the thermal design of devices. Here we report electric voltage generation from heat flowing in an insulator. We reveal that, despite the absence of conduction electrons, the magnetic insulator LaYFeO can convert a heat flow into a spin voltage. Attached Pt films can then transform this spin voltage into an electric voltage as a result of the inverse spin Hall effect. The experimental result require us to introduce a thermally activated interface spin exchange between LaYFeO and Pt. Our findings extend the range of potential materials for thermoelectric applications and provide a crucial piece of information for understanding the physics of the spin Seebeck effect.
Yoshitomi, Hiroshi; Tatebe, Yosuke; Kawai, Keiichi; Kowatari, Munehiko; Nidaira, Atsushi; Fukami, Tomoyo; Sawahata, Katsunori
no journal, ,
no abstracts in English
Yoshitomi, Hiroshi; Tatebe, Yosuke; Kowatari, Munehiko; Kawai, Keiichi; Miyauchi, Hideaki; Yoshizawa, Michio
no journal, ,
no abstracts in English
Yoshitomi, Hiroshi; Tanimura, Yoshihiko; Tatebe, Yosuke; Kawai, Keiichi; Kowatari, Munehiko; Yoshizawa, Michio
no journal, ,
no abstracts in English
Yoshitomi, Hiroshi; Tatebe, Yosuke; Kawai, Keiichi; Kowatari, Munehiko; Yoshizawa, Michio
no journal, ,
no abstracts in English
Sasaki, Yosuke*; Takayama, Yusuke*; Ikuta, Yuki*; Iizuka, Atsushi*; Kawai, Katsuyuki*; Sakao, Ryota; Taki, Tomihiro
no journal, ,
As part of environmental remediation of Ningyo-toge Uranium Mine, multi-layered capping is constructed to reduce rainwater infiltration at the upstream of the Mill Tailings Pond. Settlement is expected due to consolidation characteristics of mill tailings and clayish sediments which exist below capping. Numerical simulation is carried out to expect the settlement amount during and after the capping construction. Settlement amount has been measured periodically, and the simulation result and measurement data are compared to evaluate the simulation method.
Terada, Kentaro*; Sato, Akira*; Ninomiya, Kazuhiko*; Kawashima, Yoshitaka*; Shimomura, Koichiro*; Tomono, Dai*; Kawai, Yosuke*; Osawa, Takahito; Tachibana, Shogo*
no journal, ,
In recent years, analysis of characteristic X-rays from muonic atoms, in which a muon is captured, has attracted attention because both a muon beam and a muon-induced characteristic X-ray have high transmission abilities, of which energies are about 200 times higher. From these features, a muonic X-ray analysis has great advantages in several ways. At the conference, we will report on our recent progress of muonic X-ray analysis and discuss on a future prospect for applications for Earth and planetary science.