Present status of J-PARC MUSE

Shimomura, Koichiro*; Koda, Akihiro*; Pant, A. D.*; Natori, Hiroaki*; Fujimori, Hiroshi*; Umegaki, Izumi*; Nakamura, Jumpei*; Tampo, Motonobu*; Kawamura, Naritoshi*; Teshima, Natsuki*; et al.

Journal of Physics; Conference Series, 2462, p.012033_1 - 012033_5, 2023/03

https://doi.org/10.1088/1742-6596/2462/1/012033

Reactor noise power-spectral analysis for a graphite-moderated and -reflected core, 3

Sakon, Atsushi*; Hashimoto, Kengo*; Sano, Tadafumi*; Nakajima, Kunihiro*; Kanda, Shun*; Goto, Masaki*; Fukaya, Yuji; Okita, Shoichiro; Fujimoto, Nozomu*; Takahashi, Yoshiyuki*

KURNS Progress Report 2021, P. 100, 2022/07

https://www.rri.kyoto-u.ac.jp/PUB/report/PR/ProgRep2021/ProgRep2021.html

The R&D of reactor noise analysis to obtain HTGR nuclear characteristics have been performed with Kyoto University Critical Assembly (KUCA). In the last study, a neutron detector located about 55 cm away of fuel assembly measured the auto power spectral density. However, the prompt neutron decay constants obtained by this detector was different from that of other detectors. The objective of this study is experimental study of reactor noise analysis by the power spectrum method using neutron detector placed outside reactor core.

Time evolution calculation of muon catalysed fusion; Emission of recycling muons from a two-layer hydrogen film

Yamashita, Takuma*; Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.

Fusion Engineering and Design, 169, p.112580_1 - 112580_5, 2021/08

https://doi.org/10.1016/j.fusengdes.2021.112580

A muon () having 207 times larger mass of electron and the same charge as the electron has been known to catalyze a nuclear fusion between deuteron (d) and triton (t). These two nuclei are bound by and form a muonic hydrogen molecular ion, dt. Due to the short inter-nuclear distance of dt, the nuclear fusion, d +t + n + 17.6 MeV, occurs inside the molecule. This reaction is called muon catalyzed fusion (CF). Recently, the interest on CF is renewed from the viewpoint of applications, such as a source of high-resolution muon beam and mono-energetic neutron beam. In this work, we report a time evolution calculation of CF in a two-layered hydrogen isotope target.

Rabi-oscillation spectroscopy of the hyperfine structure of muonium atoms

Nishimura, Shoichiro*; Torii, Hiroyuki*; Fukao, Yoshinori*; Ito, Takashi; Iwasaki, Masahiko*; Kanda, Sotaro*; Kawagoe, Kiyotomo*; Kawall, D.*; Kawamura, Naritoshi*; Kurosawa, Noriyuki*; et al.

Physical Review A, 104(2), p.L020801_1 - L020801_6, 2021/08

https://doi.org/10.1103/PhysRevA.104.L020801

Simulation of Lagrangian pollutant in Jakarta urban district using Lattice Boltzmann method

Yokouchi, Hiroshi*; Inagaki, Atsushi*; Kanda, Manabu*; Onodera, Naoyuki

Doboku Gakkai Rombunshu, B1 (Suikogaku) (Internet), 76(2), p.I_253 - I_258, 2020/00

https://doi.org/10.2208/jscejhe.76.2_I_253

Hight-resolution pollutant model embedded into Lattice Boltzmann method (LBM) is constructed. We focuses on Particle pollutants. Flow field is calculated using D3Q27 model of LBM and particle is calculated by Lagrangian method. Using this model, we discuss the change in concentration distribution when there is a huge building (GARUDA) in Jakarta as a application. As a result, we can find the relation of differences in particle density and differences in flow velocity due to GARUDA. When the velocity in the case w/o GARUDA is faster than the other, particle velocity in the case w/o GARUDA is reduced. And also, we can find the velocity near the solid boundary is underestimated and the particle density is higher than theoretical value. However, this model is valid far away from the solid boundary.

New precise measurements of muonium hyperfine structure at J-PARC MUSE

Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.

EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01

https://doi.org/10.1051/epjconf/201919800003

A Numerical study of turbulence statistics and the structure of a spatially-developing boundary layer over a realistic urban geometry

Inagaki, Atsushi*; Kanda, Manabu*; Ahmad, N. H.*; Yagi, Ayako*; Onodera, Naoyuki; Aoki, Takayuki*

Boundary-Layer Meteorology, 164(2), p.161 - 181, 2017/08

https://doi.org/10.1007/s10546-017-0249-y

The applicability of outer-layer scaling is examined by numerical simulation of a developing neutral boundary layer over a realistic building geometry of Tokyo. Large-eddy simulations are carried out over a large computational domain 19.2 km 4.8 km 1 km, with a fine grid spacing (2 m) using the lattice-Boltzmann method with massively parallel graphics processing units. Results from simulations show that outer-layer features are maintained for turbulence statistics in the upper part of the boundary layer, as well as the width of predominant streaky structures throughout the entire boundary layer. This is caused by the existence of very large streaky structures extending throughout the entire boundary layer, which follow outer-layer scaling with a self-preserving development. We assume the top-down mechanism in the physical interpretation of results.

The Uranium waste fluid processing examination by liquid and liquid extraction method using the emulsion flow method

Kanda, Nobuhiro; Daiten, Masaki; Endo, Yuji; Yoshida, Hideaki; Mita, Yutaka; Naganawa, Hirochika; Nagano, Tetsushi; Yanase, Nobuyuki

JAEA-Technology 2015-007, 43 Pages, 2015/03

JAEA-Technology-2015-007.pdf:5.33MB

The centrifuge which has the subtlety information concerning the nuclear nonproliferation used for uranium enrichment technical development exists in the uranium enrichment facilities of Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency. This centrifugal is performing separation processing of the radioactive material adhering to the surface of parts by wet decontamination of ultrasonic cleaning by dilute sulfuric acid and water, etc. By removing the uranium contained in waste fluid, generated sludge reduces activity concentration. And the possibility of reduction of sludge processing is examined. For this reason, from the 2007 fiscal year, Nuclear Science and Engineering Directorate and cooperation are aimed at, and development of the extraction separation technology of the "uranium" by the emulsion flow method is furthered. The test equipment using the developed emulsion flow method was tested. And dilute sulfuric acid and water were used for the examination as actual waste fluid. The result checked whether the various performances in Basic test carried out in Nuclear Science and Engineering Directorate would be obtained.

Measurement of radiolytic yield of nitric acid in air

Kanda, Yukio*; Oki, Yuichi*; Yokoyama, Sumi; Sato, Kaoru; Noguchi, Hiroshi; Tanaka, Susumu*; Iida, Takao*

Radiation Physics and Chemistry, 74(5), p.338 - 340, 2005/12

https://doi.org/10.1016/j.radphyschem.2005.03.006

The operation of high-energy accelerators leads to the production of radiolytic noxious gases, such as ozone and nitrogen compounds in the air of the beam-line tunnels. Among nitrogen compounds, nitric acid is a principal radiolytic compound produced in large quantities. In the high-intensity proton accelerator, such as J-PARC, a very strong radiation environment leads to an abundant production of nitric acid. A quantitative assessment of the damage due to corrosion with nitric acid is essential for machine maintenance and information concerning the formation of nitric acid is a requisite for that. In this work, the G-value for nitric acid production was measured by irradiating atmospheric air with 48MeV-protons. The G-value was obtained to be 1.460.12. The G-value for nitric acid production obtained in this experiment was larger than the estimated value, but very close to the value of 1.5 given by irradiating the air with Co-60-rays.

Design of the anchor wall using 3D finite element method

Iha, Akane*; Matsubara, Hitoshi; Iraha, Shigeo*; Kanda, Yasuyuki*

Konkurito Kogaku Nenji Rombunshu (DVD-ROM), 27(2), p.1663 - 1668, 2005/00

The concrete structures such a reactor building are able to resist external forces by interaction behavior such as concrete, reinforcements, steel frames and the foundation. Therefore, it is a very important subject to solve analytically the displacement behavior and the stress distribution because the safety of structures and safe security can be offered by it. In general, such a problem is solved by using the beam theory. However, it is impossible to evaluate the different behavior or stress distribution on every component. In this paper, 3-dimensional finite element analysis of full-scale anchor wall is performed. In addition, all composition material is taken into consideration in this analysis. Consequently, concrete interaction behavior with many components is solved, and the displacement behavior and concentration of stress also is elucidated.