Axial U(1) symmetry at high temperatures in lattice QCD with chiral fermions

Aoki, Sinya*; Aoki, Yasumichi*; Fukaya, Hidenori*; Hashimoto, Shoji*; Kanamori, Issaku*; Kaneko, Takashi*; Nakamura, Yoshifumi*; Rohrhofer, C.*; Suzuki, Kei

Proceedings of Science (Internet), 396, p.332_1 - 332_7, 2022/07

https://doi.org/10.22323/1.396.0332

The axial U(1) anomaly in high-temperature QCD plays an important role to understand the phase diagram of QCD. The previous works by JLQCD Collaboration studied high-temperature QCD using 2-flavor dynamical chiral fermions such as the domain-wall fermion and reweighted overlap fermion. We extend our simulations to QCD with 2+1-flavor dynamical quarks, where the masses of the up, down, and strange quarks are near the physical point, and the temperatures are close to or higher than the pseudocritical temperature. In this talk, we will present the results for the Dirac spectrum, topological susceptibility, axial U(1) susceptibility, and hadronic collelators.

Examination of exposure management method for the eye lens at Oarai Research and Development Institute

Matsuoka, Amane; Yasumune, Takashi; Kojima, Nobuhiro; Miyauchi, Hideaki; Takasaki, Koji; Hashimoto, Makoto

JAEA-Review 2021-055, 11 Pages, 2021/12

JAEA-Review-2021-055.pdf:1.12MB

The dose limit for the eye lens was lowered on April 1 2021, and a 3 mm dose equivalent was added to the calculation. The guidelines require that lens dosimeters be worn and managed when there is a risk of exceeding control standards. In this report, in order to examine future management methods, we investigated whether work that might exceed the equivalent dose limit was performed in the past. As a result of the investigation, the exposure dose for all works after fiscal year 2008 was sufficiently low compared to the equivalent dose limit. For this reason, it is considered that there is no need for additional management of wearing a personal dosimeter near the eyes for the work that is normally performed. In the future, as in the past, the basic management method will be to wear a dosimeter only on the basic part of the trunk under uniform exposure conditions, and to wear a dosimeter on the basic part of the trunk and the maximum dose part under nonuniform exposure conditions. When performing work with a high exposure dose to the eye lens, a dosimeter should be worn near the eye to measure the 3 mm dose equivalent.

Investigation and consideration on evaluation of radiation doses to residents in the case of a nuclear emergency

Hashimoto, Makoto; Kinase, Sakae; Munakata, Masahiro; Murayama, Takashi; Takahashi, Masa; Takada, Chie; Okamoto, Akiko; Hayakawa, Tsuyoshi; Sukegawa, Masato; Kume, Nobuhide*; et al.

JAEA-Review 2020-071, 53 Pages, 2021/03

JAEA-Review-2020-071.pdf:2.72MB

In the case of a nuclear accident or a radiological emergency, the Japan Atomic Energy Agency (JAEA), as a designated public corporation assigned in the Disaster Countermeasures Basic Act and the Armed Attack Situation Response Law, undertakes technical supports to the national government and local governments. The JAEA is requested to support to evaluate radiation doses to residents in a nuclear emergency, which is specified in the Basic Disaster Management Plan and the Nuclear Emergency Response Manual. For the dose evaluation, however, its strategy, target, method, structure and so on have not been determined either specifically or in detail. This report describes the results of investigation and consideration discussed in the "Working Group for Radiation Dose Evaluation at a Nuclear Emergency" established within the Nuclear Emergency Assistance and Training Center to discuss technical supports for radiation dose evaluation to residents in the case of a nuclear emergency, and aims at contributing to specific and detailed discussion and activities in the future for the national government and local governments, also within the JAEA.

Consideration of relationship between decommissioning with digital-twin and knowledge management

Taruta, Yasuyoshi; Yanagihara, Satoshi*; Hashimoto, Takashi*; Kobayashi, Shigeto*; Iguchi, Yukihiro; Kitamura, Koichi; Koda, Yuya; Tomoda, Koichi

Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 8 Pages, 2020/08

https://doi.org/10.1115/ICONE2020-16457

Decommissioning is a long-term project during which generations are expected to change. Therefore, it is necessary to appropriately transfer knowledge and technology to the next generation. In recent years, in the world of decommissioning, attempts have been made to apply advanced technologies such as utilization of knowledge management and virtual reality. This study describes adaptation in decommissioning from the viewpoint of utilizing IT technology called digital twin from the viewpoint of knowledge management.

Room temperature and low-field resonant enhancement of spin Seebeck effect in partially compensated magnets

Ramos, R.*; Hioki, Tomosato*; Hashimoto, Yusuke*; Kikkawa, Takashi*; Frey, P.*; Kreil, A. J. E.*; Vasyuchka, V. I.*; Serga, A. A.*; Hillebrands, B.*; Saito, Eiji

Nature Communications (Internet), 10, p.5162_1 - 5162_8, 2019/11

https://doi.org/10.1038/s41467-019-13121-5

Activity median aerodynamic diameter relating to contamination at Plutonium Fuel Research Facility in Oarai Research and Development Center; Particle size analysis for plutonium particles using imaging plate

Takasaki, Koji; Yasumune, Takashi; Hashimoto, Makoto; Maeda, Koji; Kato, Masato; Yoshizawa, Michio; Momose, Takumaro

JAEA-Review 2019-003, 48 Pages, 2019/03

JAEA-Review-2019-003.pdf:3.81MB

June 6, 2017, at Plutonium Fuel Research Facility in Oarai Research and Development Center of JAEA, when five workers were inspecting storage containers containing plutonium and uranium, resin bags in a storage container ruptured, and radioactive dust spread. Though they were wearing a half face mask respirator, they inhaled radioactive materials. In the evaluation of the internal exposure dose, the aerodynamic radioactive median diameter (AMAD) is an important parameter. We measured 14 smear samples and a dust filter paper with imaging plates, and estimated the AMAD by image analysis. As a result of estimating the AMAD, from the 14 smear samples, the AMADs are 4.3 to 11 m or more in the case of nitrate plutonium, and the AMADs are 5.6 to 14 m or more in the case of the oxidized plutonium. Also, from the dust filter paper, the AMAD is 3.0 m or more in the case of nitrate plutonium, and the AMAD is 3.9 m or more in the case of the oxidized plutonium.

New measurement of the Li(,n)B reaction in a lower-energy region below the Coulomb barrier

Das, S. K.*; Fukuda, Tomokazu*; Mizoi, Yutaka*; Ishiyama, Hironobu*; Miyatake, Hiroari*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Jeong, S. C.*; Ikezoe, Hiroshi*; Matsuda, Makoto; et al.

Physical Review C, 95(5), p.055805_1 - 055805_4, 2017/05

https://doi.org/10.1103/PhysRevC.95.055805

Development of ITER CODAC compatible gyrotron local control system and its operation

Oda, Yasuhisa; Oshima, Katsumi; Nakamoto, Takashi*; Hashimoto, Yasunori*; Yamamoto, Tsuyoshi; Hayashi, Kazuo*; Ikeda, Yukiharu; Ikeda, Ryosuke; Kajiwara, Ken; Takahashi, Koji; et al.

Purazuma, Kaku Yugo Gakkai-Shi, 90(7), p.365 - 373, 2014/07

https://cir.nii.ac.jp/crid/1570854177951360512

no abstracts in English

Neutron resonance imaging of a Au-In-Cd alloy for the JSNS

Oi, Motoki; Teshigawara, Makoto; Kai, Tetsuya; Harada, Masahide; Maekawa, Fujio; Futakawa, Masatoshi; Hashimoto, Eiko*; Segawa, Mariko; Kureta, Masatoshi; Tremsin, A.*; et al.

Physics Procedia, 43, p.337 - 342, 2013/04

https://doi.org/10.1016/j.phpro.2013.03.040

The Japan Spallation Neutron Source (JSNS) at the Japan Proton Accelerator Research Complex (J-PARC) had been developed as a 1-MW spallation neutron source. A Au-In-Cd alloy has been proposed as a new decoupler material. Recently, we successfully produced the ternary Au-In-Cd alloy. The alloy composition is 74.9 at% Au, 0.5 at% In, and 24.6 at% Cd. We used the pulsed neutron imaging techniques to measure the elements in the Au-In-Cd alloy. Both a time gated camera system and a multi-channel plate (MCP) detector were used as detectors. Measurement was performed at BL10 in the JSNS. A Au-In-Cd specimen, In foil and two Au foils are used as a sample. As a results, we could obtain distribution of Au, In and Cd in the Au-In-Cd specimens distinctly.

Tolerance of anhydrobiotic eggs of the tardigrade to extreme environments

Horikawa, Daiki*; Yamaguchi, Ayami*; Sakashita, Tetsuya; Tanaka, Daisuke*; Hamada, Nobuyuki*; Yukuhiro, Fumiko*; Kuwahara, Hirokazu*; Kunieda, Takekazu*; Watanabe, Masahiko*; Nakahara, Yuichi*; et al.

Astrobiology, 12(4), p.283 - 289, 2012/04

https://doi.org/10.1089/ast.2011.0669

We examined the hatchability of hydrated and anhydrobiotic eggs of the tardigrade to hatch after ionizing irradiation (helium ions), extremely low and high temperatures, and high vacuum. Anhydrobiotic eggs (50% lethal dose; 1690 Gy) were substantially more radioresistant than hydrated ones (50% lethal dose; 509 Gy). Anhydrobiotic eggs also have a broader temperature resistance compared with hydrated ones. Over 70% of the anhydrobiotic eggs treated at high and low temperatures, but all of the hydrated eggs failed to hatch. After exposure to high vacuum conditions, the hatchability of the anhydrobiotic eggs was comparable to that of untreated control eggs.