Development of divertor simulation research in the GAMMA 10/PDX tandem mirror

Nakashima, Yosuke*; Sakamoto, Mizuki*; Yoshikawa, Masayuki*; Oki, Kensuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; et al.

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Structural investigation of magnetocapacitive SmMnO

Maeda, Hiroki*; Ishiguro, Yuki*; Honda, Takashi*; Jung, J.-S.*; Michimura, Shinji*; Inami, Toshiya; Kimura, Tsuyoshi*; Wakabayashi, Yusuke*

Journal of the Ceramic Society of Japan, 121(3), p.265 - 267, 2013/03

https://doi.org/10.2109/jcersj2.121.265

Structural deformation of a magnetocapacitive material SmMnO was studied by X-ray diffraction measurement in a magnetic field. This antiferromagnetic material shows a jump in dielectric constant at 9 K only when a magnetic field of a few tesla is applied. In-field X-ray diffraction measurements clarified that there is no sudden change in structure that involves atomic displacement within the c-plane in Pbnm notation, while the antiferromagnetic phase transition at 60 K gives rise to a noticeable rotation of the MnO octahedra. This rotation occurs to maximize the energy gain through the exchange interaction.

Seismic structural response analysis considering fault-structure system; Application to nuclear power plant structures

Quinay, P. E. B.; Ichimura, Tsuyoshi*; Hori, Muneo*; Wijerathne, M. L. L.*; Nishida, Akemi

Progress in Nuclear Science and Technology (Internet), 2, p.516 - 523, 2011/10

https://doi.org/10.15669/pnst.2.516

In this paper, we conducted a numerical analysis based on a fault-structure system. We developed a full three dimensional model that includes from a fault to structures at the surface. However, huge computational cost is required to solve these components simultaneously. Ichimura and Hori (2009a) presented a macro-micro analysis method based on singular perturbation expansion to reduce computational cost. We implemented a highly tuned finite-element code for macro-micro analysis systems to handle large-scale wave propagation in a complicated crust structure as well as the seismic response of a structure at the surface. After verifying the accuracy by comparing the results with analytical Green's function solutions, we demonstrate a seismic response using a model of a nuclear power plant structure. Our methodology can enable detailed prediction of the seismic response of a nuclear facility, permitting the generation of more reliable estimates of the seismic safety of nuclear facilities.

A Physical modeling approach for seismic response estimation of nuclear power plant structures

Quinay, P. E. B.; Ichimura, Tsuyoshi*; Hori, Muneo*; Nishida, Akemi

Proceedings of 3rd ASEAN Civil Engineering Conference/3rd ASEAN Environmental Engineering Conference/1st Seminar on Asian Water Environments 2010, 5 Pages, 2010/11

In this study, a physical modeling-based approach, the fault-structure system (FSS) analysis is presented for estimating the response of nuclear power plant structure under a scenario earthquake. To efficiently solve the FSS, a method based on multi-scale approach, the Macro-Micro Analysis (MMA) method (Ichimura and Hori, 2007) is used. Results show that the complicated response of the structure can be modeled by using the FSS. In order to obtain high resolution crust structure information for FSS analysis, an inversion method that minimizes an objective function by step-wise increase in target frequency is presented. This study takes advantage of the present computational resources to obtain high resolution outputs for seismic analysis of important structures.

Overview of the national centralized tokamak programme

Kikuchi, Mitsuru; Tamai, Hiroshi; Matsukawa, Makoto; Fujita, Takaaki; Takase, Yuichi*; Sakurai, Shinji; Kizu, Kaname; Tsuchiya, Katsuhiko; Kurita, Genichi; Morioka, Atsuhiko; et al.

Nuclear Fusion, 46(3), p.S29 - S38, 2006/03

https://doi.org/10.1088/0029-5515/46/3/S05

The National Centralized Tokamak (NCT) facility program is a domestic research program for advanced tokamak research to succeed JT-60U incorporating Japanese university accomplishments. The mission of NCT is to establish high beta steady-state operation for DEMO and to contribute to ITER. The machine flexibility and mobility is pursued in aspect ratio and shape controllability, feedback control of resistive wall modes, wide current and pressure profile control capability for the demonstration of the high-b steady state.

Design study of national centralized tokamak facility for the demonstration of steady state high- plasma operation

Tamai, Hiroshi; Akiba, Masato; Azechi, Hiroshi*; Fujita, Takaaki; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; Hosogane, Nobuyuki; Ichimura, Makoto*; et al.

Nuclear Fusion, 45(12), p.1676 - 1683, 2005/12

https://doi.org/10.1088/0029-5515/45/12/023

Design studies are shown on the National Centralized Tokamak facility. The machine design is carried out to investigate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-beta steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluations of the plasma performance towards the determination of machine design are presented.

Study of the ion cyclotron emission due to D-D fusion-product H-ions on JT-60U

Sato, Shoichi*; Ichimura, Makoto*; Yamaguchi, Yusuke*; Katano, Makoto*; Imai, Yasutaka*; Murakami, Tatsuya*; Miyake, Yuichiro*; Yokoyama, Takuro*; Moriyama, Shinichi; Kobayashi, Takayuki; et al.

no journal, , 

Ion cyclotron emissions (ICEs) due to deuterium-deuterium fusion-product (FP) ions on JT-60U are studied. ICE due to H-ions is identified from the difference of the toroidal wave number of 2nd ICE(D). The parameter dependence for the appearance of ICE(H) is investigated from the experimental conditions and also is studied by using "Escape Particle Orbit analysis Code (EPOC)".

Generation and characterization of detached plasma in the GAMMA 10/PDX end-cell

Nakashima, Yosuke*; Ichimura, Kazuya*; Takeda, Hisahito*; Iwamoto, Miki*; Hosoda, Yasunari*; Shimizu, Keita*; Oki, Kensuke*; Sakamoto, Mizuki*; Ono, Noriyasu*; Kado, Shinichiro*; et al.

no journal, , 

no abstracts in English