Alternation of magnetic anisotropy accompanied by metal-insulator transition in strained ultrathin manganite heterostructures

Kobayashi, Masaki*; Anh, L. D.*; Suzuki, Masahiro*; Kaneta-Takada, Shingo*; Takeda, Yukiharu; Fujimori, Shinichi; Shibata, Goro*; Tanaka, Arata*; Tanaka, Masaaki*; Oya, Shinobu*; et al.

Physical Review Applied (Internet), 15(6), p.064019_1 - 064019_10, 2021/06

https://doi.org/10.1103/PhysRevApplied.15.064019

Thermally altered subsurface material of asteroid (162173) Ryugu

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.

Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03

https://doi.org/10.1038/s41550-020-01271-2

Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.

Characterization of the PTW 34031 ionization chamber (PMI) at RCNP with high energy neutrons ranging from 100 - 392 MeV

Theis, C.*; Carbonez, P.*; Feldbaumer, E.*; Forkel-Wirth, D.*; Jaegerhofer, L.*; Pangallo, M.*; Perrin, D.*; Urscheler, C.*; Roesler, S.*; Vincke, H.*; et al.

EPJ Web of Conferences, 153, p.08018_1 - 08018_5, 2017/09

https://doi.org/10.1051/epjconf/201715308018

At CERN, gas-filled ionization chambers PTW-34031 (PMI) are commonly used in radiation fields including neutrons, protons and -rays. A response function for each particle is calculated by the radiation transport code FLUKA. To validate a response function to high energy neutrons, benchmark experiments with quasi mono-energetic neutrons have been carried out at RCNP, Osaka University. For neutron irradiation with energies below 200 MeV, very good agreement was found comparing the FLUKA simulations and the measurements. In addition it was found that at proton energies of 250 and 392 MeV, results calculated with neutron sources underestimate the experimental data due to a non-negligible gamma component originating from the target Li(p,n)Be reaction.

Dipole tracer migration and diffusion tests in fractured sedimentary rock at Horonobe URL

Tanaka, Shingo*; Yokota, Hideharu; Ono, Hirokazu; Nakayama, Masashi; Fujita, Tomoo; Takiya, Hiroaki*; Watanabe, Naoko*; Kozaki, Tamotsu*

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 6 Pages, 2015/05

Development of new type passive autocatalytic recombiner, 1; Characterization of monolithic catalyst

Kamiji, Yu; Taniguchi, Masashi*; Nishihata, Yasuo; Nagaishi, Ryuji; Tanaka, Hirohisa*; Hirata, Shingo*; Hara, Mikiya; Hino, Ryutaro

Proceedings of 2nd International Conference on Maintenance Science and Technology (ICMST-Kobe 2014), p.87 - 88, 2014/11

For hydrogen mitigation, a new type passive autocatalytic recombiner is under development. In this study, the activation energy of hydrogen-oxygen recombination reaction was examined to clarify the basic characteristics of the catalyst. In addition, the degradation of the catalyst by -ray irradiation simulating the environmental condition in nuclear power plants was also examined. As a result, the activation energy was experimentally estimated at 5.75 kJ/mol. Besides, no significant differences were observed in the compositional distribution from the EPMA results between the non-irradiated and the irradiated catalyst. However, the irradiated catalyst showed much more activity because of larger specific surface area of the catalyst and surface area of the precious metals. It showed that -ray irradiation up to 1.0 MGy can increase activity of the catalyst.

Investigation and research on depth distribution in soil of radionuclides released by the TEPCO Fukushima Dai-ichi Nuclear Power Plant accident

Sato, Haruo; Niizato, Tadafumi; Amano, Kenji; Tanaka, Shingo; Aoki, Kazuhiro

Materials Research Society Symposium Proceedings, Vol.1518, p.277 - 282, 2013/10

https://doi.org/10.1557/opl.2013.393

The accident of the TEPCO Fukushima Dai-ichi Nuclear Power Plant occurred by the 2011 off the Pacific coast of Tohoku Earthquake on 11 March, 2011. It is estimated that 1.2-1.510 Bq for Cs and 1.5-1.610 Bq for I-131 were released until the beginning of April and those radionuclides (RN) were deposited on soil surface and forest etc. widely around Fukushima Pref. This work was carried out as one of the investigations for making the distribution maps of radiation dose rate and soil contaminated by RNs which the MEXT promotes. The Geoslicer investigation on the depth distribution of RNs in soil was carried out after 3 months from the accident. The investigation was conducted at 11 locations in Nihonmatsu City, Kawamata Town and Namie Town, and soil samples of depth 50 cm to 1 m were taken. Both of Cs and Cs were detected in all investigated locations, and Te and Ag were detected only in areas where radiation dose rates are high. At many locations investigated, radiocaesium more than 99% distributed within a depth of 10 cm in soil in the surface layer. On the other hand, RNs tended to distribute to deeper part in soil at locations that are supposed to have been used as farmland than in soil in the surface layer, and radiocaesium more than 99% in soil at locations that are supposed to have been used as farmland also distributed within a depth of around 14 cm. The apparent diffusion coefficients of RNs derived from penetration profiles near the surface layer showed a tendency to be higher in soil at locations that are supposed to have been used as farmland than in soil in the surface layer. The distribution coefficients by a batch method were also obtained for Cs and I, and the relationship between D and K was discussed.

Horonobe Underground Research Laboratory Project; Investigation report for the 2011 fiscal year

Nakayama, Masashi; Amano, Kenji; Tokiwa, Tetsuya; Yamamoto, Yoichi; Oyama, Takuya; Amano, Yuki; Murakami, Hiroaki; Inagaki, Daisuke; Tsusaka, Kimikazu; Kondo, Keiji; et al.

JAEA-Review 2012-035, 63 Pages, 2012/09

JAEA-Review-2012-035.pdf:12.23MB

The Horonobe Underground Research Laboratory Project is planned to extend over a period 20 years. The investigations will be conducted in three phases, namely "Phase 1: Surface-based investigations", "Phase 2: Construction Phase" (investigations during construction of the underground facilities) and "Phase 3: Operation phase"(research in the underground facilities). This report summarizes the results of the investigations for the 2011 fiscal year (2011/2012). The investigations, which are composed of "Geoscientific research" and "R&D on geological disposal technology", were carried out according to "Horonobe Underground Research Laboratory Project Investigation Program for the 2011 Fiscal year". The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. For the sake of this, JAEA has proceeded with the project in collaboration with experts from domestic and overseas research organisations.

Identified charged hadron production in collisions at = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

https://doi.org/10.1103/PhysRevC.83.064903

Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

Metamagnetic behavior in heavy-fermion compound YbIrZn

Takeuchi, Tetsuya*; Yasui, Shinichi*; Toda, Masatoshi*; Matsushita, Masaki*; Yoshiuchi, Shingo*; Oya, Masahiro*; Katayama, Keisuke*; Hirose, Yusuke*; Yoshitani, Naohisa*; Honda, Fuminori*; et al.

Journal of the Physical Society of Japan, 79(6), p.064609_1 - 064609_15, 2010/06

https://doi.org/10.1143/JPSJ.79.064609

Heavy fermion state in YbIrZn

Yoshiuchi, Shingo*; Toda, Masatoshi*; Matsushita, Masaki*; Yasui, Shinichi*; Hirose, Yusuke*; Oya, Masahiro*; Katayama, Keisuke*; Honda, Fuminori*; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; et al.

Journal of the Physical Society of Japan, 78(12), p.123711_1 - 123711_4, 2009/12

https://doi.org/10.1143/JPSJ.78.123711