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2. Development of Three-Dimensional Neoclassical Transport Simulation Code with High Performance Fortran on a Vector-Parallel Computer

Author

Satake, Shinsuke, Okamoto, Masao, Nakajima, Noriyoshi, Takamaru, Hisanori, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Labarta, Jesús, editor, Joe, Kazuki, editor, and Sato, Toshinori, editor

Published
2008
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3. Distributed Parallelization of Exact Charge Conservative Particle Simulation Code by High Performance Fortran

Author

Hasegawa, Hiroki, Ishiguro, Seiji, Okamoto, Masao, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Labarta, Jesús, editor, Joe, Kazuki, editor, and Sato, Toshinori, editor

Published
2008
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4. Characteristics of MHD instabilities limiting the beta value in LHD

Author

SAKAKIBARA, Satoru, WATANABE, Kiyomasa, TAKEMURA, Yuki, OKAMOTO, Masao, OHDACHI, Satoshi, SUZUKI, Yasuhiro, NARUSHIMA, Yoshiro, IDA, Katsumi, YOSHINUMA, Mikiro, TANAKA, Kenji, TOKUZAWA, Tokihiko, YAMADA, Ichihiro, YAMADA, Hiroshi, TAKEIRI, Yasuhiko, LHD, Experiment Group, SAKAKIBARA, Satoru, WATANABE, Kiyomasa, TAKEMURA, Yuki, OKAMOTO, Masao, OHDACHI, Satoshi, SUZUKI, Yasuhiro, NARUSHIMA, Yoshiro, IDA, Katsumi, YOSHINUMA, Mikiro, TANAKA, Kenji, TOKUZAWA, Tokihiko, YAMADA, Ichihiro, YAMADA, Hiroshi, TAKEIRI, Yasuhiko, and LHD, Experiment Group

Abstract

Effects of low-n magnetohydrodynamic instabilities on plasma performance have been assessed in the regime where an achieved beta value is limited by instabilities. The unstable regime of an ideal interchange mode is characterized by enhanced magnetic hill and reduced magnetic shear. Experiments have clarified that (i) low-n modes are significantly destabilized in the ideal-unstable configurations and lead to degradation of central beta by at most 60%, and (ii) the degree of their damages strongly depends on the mode rotation velocity. The occurrence of the minor collapse is independent of an existence of an error field., source:S. Sakakibara et al 2015 Nucl. Fusion 55 083020, source:https://doi.org/10.1088/0029-5515/55/8/083020, identifier:0000-0002-3306-0531

Published
2022

8. Generation of the sheared radial electric field by a magnetic island structure

Author

Aleksandra Maluckov, Ana Mančić, Yokoyama Masayoshi, and Okamoto Masao

Subjects
Physics, General Engineering, Ocean Engineering, Context (language use), Plasma, Mechanics, Electron, Optical field, Classification of discontinuities, Electric flux, Nuclear magnetic resonance, Electric field, Astrophysics::Earth and Planetary Astrophysics, Diffusion (business)
Abstract

The effect of the presence of a magnetic island structure on the am bipolar radial electric field is studied in the context of the belt island model. It is shown that the sheared radial electric field region exists on the island position. Depending on the model parameters, the single (ion root) or multiple (one ion and two electron roots) solutions for the radial electric field are obtained at different radial positions. The radially non-local treatment is developed proposing the steady-state plasma conditions. The numerical calculations show that the diffusion of the radial electric field is significant only near the island boundaries. As a result the discontinuities in the am bipolar electric field profile are smoothed.

Published
2004
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9. Study of Finite-Orbit-Width Effect on Neoclassical Transport in Tokamak Core Region

Author

SATAKE, Shinsuke and OKAMOTO, Masao

Subjects
Physics::Plasma Physics, neoclassical transport, δ f method, radial electric field, potato orbit, finite-orbit-width effect
Abstract

Neoclassical transport simulation using the δ f Monte-Carlo method is carried out to investigate the finite-orbitwidth (FOW) effect on the transport near the magnetic axis. The time evolution of the radial electric field to maintain the ambipolarity of the flux is calculated simultaneously. It is found that, in the near-axis region, the ion heat flux decreases from the value predicted by the standard neoclassical theory both in the banana and plateau regimes. Though the radial transport shows a strong dependence on the FOW effect, the ambipolar electric field profile at the steady state is similar to that calculated in the small-orbit-width limit approximation.

Published
2004

10. Characteristics of MHD instabilities limiting the beta value in LHD

Author

SAKAKIBARA, Satoru, WATANABE, Kiyomasa, TAKEMURA, Yuki, OKAMOTO, Masao, OHDACHI, Satoshi, SUZUKI, Yasuhiro, NARUSHIMA, Yoshiro, IDA, Katsumi, YOSHINUMA, Mikiro, TANAKA, Kenji, TOKUZAWA, Tokihiko, YAMADA, Ichihiro, YAMADA, Hiroshi, TAKEIRI, Yasuhiko, and LHD, Experiment Group

Subjects
Physics, helical plasma, Nuclear and High Energy Physics, MHD instability, Mode (statistics), Mechanics, Limiting, Plasma, Condensed Matter Physics, beta limit, Shear (sheet metal), Classical mechanics, Beta (plasma physics), Magnetohydrodynamic drive, Magnetohydrodynamics, Value (mathematics)
Abstract

Effects of low-n magnetohydrodynamic instabilities on plasma performance have been assessed in the regime where an achieved beta value is limited by instabilities. The unstable regime of an ideal interchange mode is characterized by enhanced magnetic hill and reduced magnetic shear. Experiments have clarified that (i) low-n modes are significantly destabilized in the ideal-unstable configurations and lead to degradation of central beta by at most 60%, and (ii) the degree of their damages strongly depends on the mode rotation velocity. The occurrence of the minor collapse is independent of an existence of an error field.

Published
2015
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28. Development of Three-Dimensional Neoclassical Transport Simulation Code with High Performance Fortran on a Vector-Parallel Computer.

Author

Hutchison, David, Kanade, Takeo, Kittler, Josef, Kleinberg, Jon M., Mattern, Friedemann, Mitchell, John C., Naor, Moni, Nierstrasz, Oscar, Pandu Rangan, C., Steffen, Bernhard, Sudan, Madhu, Terzopoulos, Demetri, Tygar, Doug, Vardi, Moshe Y., Weikum, Gerhard, Labarta, Jesús, Joe, Kazuki, Sato, Toshinori, Satake, Shinsuke, and Okamoto, Masao

Abstract

A neoclassical transport simulation code (FORTEC-3D) applicable to three-dimensional configurations has been developed using High Performance Fortran (HPF). Adoption of computing techniques for parallelization and a hybrid simulation model to the δf Monte-Carlo method transport simulation, including non-local transport effects in three-dimensional configurations, makes it possible to simulate the dynamism of global, non-local transport phenomena with a self-consistent radial electric field within a reasonable computation time. In this paper, development of the transport code using HPF is reported. Optimization techniques in order to achieve both high vectorization and parallelization efficiency, adoption of a parallel random number generator, and also benchmark results, are shown. [ABSTRACT FROM AUTHOR]

Published
2008
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30. Seikei-Kakou

Author

Orihara, Katsuo, primary, Takahashi, Hiroki, additional, Aoki, Katsuhiro, additional, and Okamoto, Masao, additional

Published
2002
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