※ 半角英数字
 年 ~ 
検索結果: 120 件中 1件目~20件目を表示


Initialising ...



Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...



New precise measurement of muonium hyperfine structure interval at J-PARC

上野 恭裕*; 青木 正治*; 深尾 祥紀*; 東 芳隆*; 樋口 嵩*; 飯沼 裕美*; 池戸 豊*; 石田 啓一*; 伊藤 孝; 岩崎 雅彦*; et al.

Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11

 被引用回数:1 パーセンタイル:17.79

MuSEUM is an international collaboration aiming at a new precise measurement of the muonium hyperfine structure at J-PARC (Japan Proton Accelerator Research Complex). Utilizing its intense pulsed muon beam, we expect a ten-fold improvement for both measurements at high magnetic field and zero magnetic field. We have developed a sophisticated monitoring system, including a beam profile monitor to measure the 3D distribution of muonium atoms to suppress the systematic uncertainty.


New muonium HFS measurements at J-PARC/MUSE

Strasser, P.*; 青木 正治*; 深尾 祥紀*; 東 芳隆*; 樋口 嵩*; 飯沼 裕美*; 池戸 豊*; 石田 啓一*; 伊藤 孝; 岩崎 雅彦*; et al.

Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12

 被引用回数:3 パーセンタイル:10.17

At the Muon Science Facility (MUSE) of J-PARC (Japan Proton Accelerator Research Complex), the MuSEUM collaboration is planning new measurements of the ground state hyperfine structure (HFS) of muonium both at zero field and at high magnetic field. The previous measurements were performed both at LAMPF (Los Alamos Meson Physics Facility) with experimental uncertainties mostly dominated by statistical errors. The new high intensity muon beam that will soon be available at MUSE H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation, and the results of a first commissioning test experiment at zero field are presented.


Space radiation dosimetry to evaluate the effect of polyethylene shielding in the Russian segment of the International Space Station

永松 愛子*; Casolino, M.*; Larsson, O.*; 伊藤 毅*; 安田 仲宏*; 北城 圭一*; 島田 健*; 武田 和雄*; 津田 修一; 佐藤 達彦

Physics Procedia, 80, p.25 - 35, 2015/12

 被引用回数:3 パーセンタイル:13.15



Evaluation of gas entrainment flow rate using numerical simulation with interface-tracking method

伊藤 啓; 大野 修司; 小泉 安郎*; 河村 拓己*

Proceedings of 10th International Topical Meeting on Nuclear Thermal Hydraulics, Operation and Safety (NUTHOS-10) (USB Flash Drive), 10 Pages, 2014/12

The gas entrainment (GE) due to free surface vortex is one of important issues in the safety study on sodium-cooled fast reactors. In this paper, the authors perform numerical simulations of a simple GE experiment. To simulate interfacial deformations accurately, a high-precision interface-tracking method is employed. Two kinds of fluids, i.e. water and silicone oil, are considered as the working fluid in the simulations and the flow rate is changed over a wide range as the simulation parameter for both fluids. As a result of the numerical simulations, the evaluated values of the entrained gas flow rates shows good agreements with the experimental data. In addition, both the simulation results and experimental data provide the entrained gas flow rate in proportional to the average velocity at the cylindrical tank outlet.


Study on numerical simulation of bubble and dissolved gas behavior in liquid metal flow

伊藤 啓; 田中 正暁; 大野 修司; 大島 宏之

JAEA-Research 2014-023, 34 Pages, 2014/11




Numerical study on inert gas behavior in fast reactor primary coolant system; Inert gas accumulation at HPP and consideration of gas elimination system

高田 孝*; 小中 祐至*; 山口 彰*; 伊藤 啓; 大野 修司; 大島 宏之

Proceedings of 9th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-9) (CD-ROM), 7 Pages, 2014/11



A High-precision calculation method for interface normal and curvature on an unstructured grid

伊藤 啓; 功刀 資彰*; 大野 修司; 上出 英樹; 大島 宏之

Journal of Computational Physics, 273, p.38 - 53, 2014/09

 被引用回数:8 パーセンタイル:34.61(Computer Science, Interdisciplinary Applications)

In the volume-of-fluid algorithm, the calculations of the interface normal and curvature are crucially important for accurately simulating interfacial flows. In this paper, the authors develop a height function method that works appropriately on an unstructured grid. In the process, the definition of the height function is discussed, and the high-precision calculation method of the interface normal is developed to meet the necessary condition for a second-order method. The curvature calculation method is also discussed and the approximated quadric curve of an interface is employed to calculate the curvature. Following a basic verification, the developed height function method is shown to successfully provide superior calculation accuracy and highly reduced computational cost compared with conventional calculation methods in terms of the interface normal and curvature.


Effect of physical properties on gas entrainment rate from free surface by vortex, 2

小泉 安郎*; 大手 直介*; 上出 英樹; 大野 修司; 伊藤 啓

Proceedings of 22nd International Conference on Nuclear Engineering (ICONE-22) (DVD-ROM), 7 Pages, 2014/07

A sodium-cooled fast breeder reactor is now at the developing stage in Japan. One concern for safety is cover gas entrainment into the sodium coolant. The gas entrainment rate into liquid by the vortex formed on the free surface was examined experimentally. Four kinds of test fluid were used; water at 25$$^{circ}$$C, water at 60 $$^{circ}$$C, 20 cSt silicone oil and kerosene. The gas entrainment rate into liquid was measured. The relation between gas entrainment rate and liquid velocity was mainly affected by the viscosity of liquid. As viscosity became large, higher exit velocity was required to get the same gas entrainment rate. No systematic trend by the surface tension was noticed in the gas entrainment rate. A flow state at the outlet piping has significant effect on the gas entrainment rate. The dimension of the outlet piping may become important to consider the gas entrainment rate in the vortex type region.


Residual strains in ITER conductors by neutron diffraction

Harjo, S.; 辺見 努; 阿部 淳; Gong, W.; 布谷 嘉彦; 相澤 一也; 伊藤 崇芳*; 小泉 徳潔; 町屋 修太郎*; 長村 光造*

Materials Science Forum, 777, p.84 - 91, 2014/02

Measurements of internal strains in the superconducting phase in two cable-in-conduit conductors (CICC) for ITER were performed using an engineering materials diffractometer TAKUMI of J-PARC. From strain measurements in a CICC for the toroidal field magnet after a performance test of cyclic current, in 100 mm long cut bars, a peak broadening and a large relaxation on residual thermal strain were observed in Nb$$_{3}$$Sn phase at a portion received a high magnetic field (high field zone). Internal strain measurements were also conducted in a CICC for the central solenoidal magnets after the similar performance test, in the full-size shape as used in the performance test (3.6 m long) and in 100 mm long cut bars. From results of the measurements the performances degradations of the ITER conductors were clarified.


超伝導転移端マイクロカロリメータによる燃料デブリの核種分析に係る研究; 高分解能測定実験及びシミュレーション計算(共同研究)

高崎 浩司; 安宗 貴志; 大西 貴士; 中村 圭佑; 石見 明洋; 伊藤 主税; 逢坂 正彦; 大野 雅史*; 畠山 修一*; 高橋 浩之*; et al.

JAEA-Research 2013-043, 33 Pages, 2014/01





伊藤 啓; 高田 孝*; 大野 修司; 粉川 広行; 上出 英樹; 今井 康友*; 河村 拓己*

日本機械学会論文集,B, 79(808), p.2630 - 2634, 2013/12




伊藤 啓; 大野 修司; 上出 英樹; 粉川 広行; 二川 正敏; 河村 拓己*; 今井 康友*

JAEA-Research 2013-008, 117 Pages, 2013/10




渦モデルによるガス巻込み・液中渦評価手法の研究; 実規模試験に対するガス巻込み評価手法の適用性検討および液中渦評価手法の基礎的検討

伊藤 啓; 江連 俊樹; 大野 修司; 上出 英樹; 中峯 由彰*; 今井 康友*

JAEA-Research 2013-007, 75 Pages, 2013/10




Effect of physical properties on gas entrainment rate from free surface by vortex

大手 直介*; 小泉 安郎*; 上出 英樹; 大野 修司; 伊藤 啓

Proceedings of 21st International Conference on Nuclear Engineering (ICONE-21) (DVD-ROM), 7 Pages, 2013/07




伊藤 啓; 江連 俊樹; 大野 修司; 上出 英樹

日本機械学会論文集,B, 79(801), p.838 - 847, 2013/05



Evaluation model of bubble-type gas entrainment

伊藤 啓; 江連 俊樹; 大野 修司; 上出 英樹

Proceedings of 15th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-15) (USB Flash Drive), 11 Pages, 2013/05



Development of small specimen test techniques for the IFMIF test cell

若井 栄一; Kim, B. J.; 野澤 貴史; 菊地 孝行; 平野 美智子*; 木村 晃彦*; 笠田 竜太*; 横峯 健彦*; 吉田 崇英*; 野上 修平*; et al.

Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 6 Pages, 2013/03

Recent progress of small specimen test technique and the engineering design and engineering validation tests of high flux test module (HFTM) for the IFMIF test cell is mainly summarized and evaluated in the IFMIF/EVEDA (Engineering validation and engineering design activities) projects under Broader Approach Agreement between EURATOM and Japan. Effects of specimen size on mechanical properties such as impact properties and ductile-to-brittle transition temperature are known to occur in ferritic/martensitic steels, and some parts of them have been prepared in the guideline and standard of mechanical tests by ASTM-international and ISO. However, our research of ferritic/martensitic steel F82H showed that it did not match with our data, i.e., master curve method for fracture in ductile-to-brittle transition behaviour of F82H steel. Accordingly, we need to modify and develop these standards for the tests including small size specimens of fusion materials in IFMIF. Also, some designs were prepared in the design of HFTM.


Modeling of free surface vortex with realistic downward velocity distribution

伊藤 啓; 江連 俊樹; 大野 修司; 上出 英樹

Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 5 Pages, 2012/12




伊藤 啓; 江連 俊樹; 大野 修司; 上出 英樹

キャビテーションに関するシンポジウム(第16回)講演論文集(USB Flash Drive), 6 Pages, 2012/11



Gas entrainment rate from free surface by vortex

小泉 安郎*; 大手 直介*; 上出 英樹; 大野 修司; 伊藤 啓

Proceedings of 6th Japanese-European Two-Phase Flow Group Meeting (USB Flash Drive), 6 Pages, 2012/09

本研究では、自由表面渦によるガス巻込み流量を実験的に計測した。試験流体は、水, 20cStのシリコンオイル,ケロシンである。流量が小さい場合、くぼみ渦先端から小さな気泡が離脱するガス巻込みが観察され、ガス巻込み流量は小さいが、流量の増加とともにガス巻込み形態が変化し、ガス巻込み流量が急増した。液位が小さい場合、後者のガス巻込み形態のみが観察され、液位の増加とともに前者の形態が観察されるようになった。粘性係数や表面張力といった流体物性がガス巻込み現象に与える影響について調査し、また、ガス巻込み開始点についてKelvin-Helmholtz不安定性によるモデル化の検討を行った。

120 件中 1件目~20件目を表示