Ishitsuka, Etsuo; Ho, H. Q.; Kitagawa, Kanta*; Fukuda, Takahito*; Ito, Ryo*; Nemoto, Masaya*; Kusunoki, Hayato*; Nomura, Takuro*; Nagase, Sota*; Hashimoto, Haruki*; et al.
JAEA-Technology 2023-013, 19 Pages, 2023/06
Eight people from five universities participated in the 2022 summer holiday practical training with the theme of "Technical development on HTTR". The participants practiced the feasibility study for nuclear battery, the burn-up analysis of HTTR core, the feasibility study for Cf production, the analysis of behavior on loss of forced cooling test, and the thermal-hydraulic analysis near reactor pressure vessel. In the questionnaire after this training, there were impressions such as that it was useful as a work experience, that some students found it useful for their own research, and that discussion with other university students was a good experience. These impressions suggest that this training was generally evaluated as good.
Wang, Y.*; Tomota, Yo*; Omura, Takahito*; Gong, W.; Harjo, S.
Materialia, 27, p.101685_1 - 101685_9, 2023/03
Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I.-H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
IEEE Transactions on Applied Superconductivity, 31(5), p.2101704_1 - 2101704_4, 2021/08
A superconducting transition-edge sensor (TES) microcalorimeter is an ideal X-ray detector for experiments at accelerator facilities because of good energy resolution and high efficiency. To study the performance of the TES detector with a high-intensity pulsed charged-particle beam, we measured X-ray spectra with a pulsed muon beam at the Japan Proton Accelerator Research Complex (J-PARC) in Japan. We found substantial temporal shifts of the X-ray energy correlated with the arrival time of the pulsed muon beam, which was reasonably explained by pulse pileup due to the incidence of energetic particles from the initial pulsed beam.
Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07
We observed electronic X rays emitted from muonic iron atoms using a superconducting transition-edge-type sensor microcalorimeter. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic and X rays together with the hypersatellite X rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the -shell electrons, accompanied by electron side-feeding. Assisted by a simulation, this data clearly reveals the electronic - and -shell hole production and their temporal evolution during the muon cascade process.
Wang, Y.*; Tomota, Yo*; Omura, Takahito*; Gong, W.*; Harjo, S.; Tanaka, Masahiko*
Acta Materialia, 196, p.565 - 575, 2020/09
Tomota, Yo*; Murakami, Toshio*; Wang, Y. X.*; Omura, Takahito*; Harjo, S.; Su, Y. H.; Shinohara, Takenao
Materials Characterization, 163, p.110243_1 - 110243_8, 2020/05
Tomota, Yo*; Wang, Y.*; Omura, Takahito*; Sekido, Nobuaki*; Harjo, S.; Kawasaki, Takuro; Gong, W.*; Taniyama, Akira*
Tetsu To Hagane, 106(5), p.262 - 271, 2020/05
Wang, Y.*; Tomota, Yo*; Omura, Takahito*; Morooka, Satoshi; Gong, W.*; Harjo, S.
Acta Materialia, 184, p.30 - 40, 2020/02
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
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.
Ueyama, Daichi*; Saito, Yuichi; Ishikawa, Norito; Omura, Takahito*; Semboshi, Satoshi*; Hori, Fuminobu*; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 351, p.1 - 5, 2015/05
Lee, C. G.; Omura, Takahito*; Takeda, Yoshihiko*; Matsuoka, Saburo*; Kishimoto, Naoki*
Journal of Nuclear Materials, 326(2-3), p.211 - 216, 2004/03
Magnesium aluminate spinel of single crystal was irradiated with 60 keV Cu at a dose rate up to 100 A/cm, to a total dose of 310 ions/cm, in order to study changes in hardness and step-height swelling by high-flux implantation. Hardness determined by nano-indentation measurements steeply decreased with implantation. There is a strong negative correlation between dose-rate dependences of the hardness and the step-height swelling: the former decreases as the latter increases. The Rutherford Backscattering Spectrometry (RBS)/channeling measurements showed that the spinel is not completely amorphized over the dose-rate range in this study, and the radiation-induced softening observed is not due to amorphization. Results of optical absorbance suggested that radiation-induced point defects and their clusters on the anion sublattices of the spinel played an important role in the radiation-induced swelling under high-flux ion implantation.
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.
Chiu, I.-H. ; Osawa, Takahito; Takeda, Shinichiro*; Katsuragawa, Miho*; Takahashi, Tadayuki*; Watanabe, Shin*; Mizumoto, Kazumi*; Saito, Tsutomu*; Kubo, Kenya*; Umegaki, Izumi*; et al.
no journal, ,
no abstracts in English
Chiu, I.-H. ; Osawa, Takahito; Takeda, Shinichiro*; Katsuragawa, Miho*; Takahashi, Tadayuki*; Watanabe, Shin*; Kubo, Kenya*; Mizumoto, Kazumi*; Saito, Tsutomu*; Umegaki, Izumi*; et al.
no journal, ,
Non-destructive elemental analysis method has been developed for the materials by high-energy muon-characteristic X-rays measurement. To further improve the method, we have also utilized two-dimensional cadmium telluride hard X-ray detectors (CdTe-DSDs) for the muonic X-rays measurement to obtain the 3D elemental distribution of the sample. In this work, a 3D imaging system has been created using four CdTe-DSDs. The experiment of 3D elemental imaging for archaeological materials was performed using a negative muon beam at J-PARC/MUSE, and the three-dimensional distribution of silicon and oxygen was confirmed. This presentation introduces the research progress so far.