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Matsuoka, Seikichi; Idomura, Yasuhiro; Satake, Shinsuke*
Physics of Plasmas, 25(2), p.022510_1 - 022510_10, 2018/02
Times Cited Count：17 Percentile：74.87(Physics, Fluids & Plasmas)Global full-f gyrokinetic simulations, in which the gyrokinetic equation is solved based on the first principle without the scale separation with respect to the plasma distribution function, is attracting much attention in the plasma transport simulation studies. In this work, in order to apply a global full-f gyrokinetic simulation code GT5D to stellarator plasmas with complicated three-dimensional magnetic field configurations, we extend finite difference scheme of GT5D and develop a new interface code which incorporates the three-dimensional magnetic equilibria provided by a standard equilibrium code, VMEC. A series of benchmark calculations are carried out for the numerical verification of GT5D. It is successfully demonstrated that GT5D well reproduces results of a theoretical analysis and another global neoclassical transport code.
Matsuoka, Seikichi; Idomura, Yasuhiro; Satake, Shinsuke*
Physics of Plasmas, 24(10), p.102522_1 - 102522_9, 2017/10
Times Cited Count：4 Percentile：21.74(Physics, Fluids & Plasmas)In axisymmetric tokamak plasmas, effects of three-dimensional non-axisymmetric magnetic field perturbations caused by error fields etc. have attracted much attention from the view point of the control of the plasma performance and instabilities. Recent studies pointed out that there exists qualitative discrepancy in predicting the collisional viscosity driven by the perturbation between a theoretical bounce-averaged model and a global kinetic simulation. Clarifying the cause of the discrepancy by understanding the underlying mechanism is a key issue to establish a reliable basis for the NTV predictions. In this work, we perform two different kinds of global kinetic simulations for the NTV. As a result, it is first demonstrated that the discrepancy arises owing to the following two mechanisms related to the global particle orbit; (1) the effective magnitude of the perturbation becomes weak due to the loss of the resonant orbit, and (2) the phase mixing along the orbit arises and generates fine scale structures, resulting the damping of the NTV.
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Akimoto, Hajime; Satake, Shinichi*
Proceedings of International Conference on Jets, Wakes and Separated Flows (ICJWSF 2005), p.137 - 144, 2005/11
no abstracts in English
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Akimoto, Hajime; Aoki, Takayuki*
Dai-24-Kai Nihon Shimyureshon Gakkai Taikai Happyo Rombunshu, p.161 - 164, 2005/07
no abstracts in English
Takase, Kazuyuki
Nihon Kikai Gakkai Ryutai Kogaku Bumon Nyuzu Reta Nagare (Internet), 6 Pages, 2005/04
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*
Hai Pafomansu Komputingu To Keisan Kagaku Shimpojium (HPCS 2005) Rombunshu, P. 16, 2005/01
no abstracts in English
; Toward superconducting tunnel junctions and superconducting radiation detectors using thermal relaxation processIshida, Takekazu*; Wang, Z.*; Yotsuya, Tsutomu*; Machida, Masahiko
Kotai Butsuri, 40(1), p.51 - 67, 2005/01
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*
Proceedings of 1st International Forum on Heat Transfer (IFHT 2004), p.207 - 208, 2004/11
no abstracts in English
Ose, Yasuo*; Takase, Kazuyuki; Yoshida, Hiroyuki
Proceedings of 1st International Forum on Heat Transfer (IFHT 2004), p.199 - 200, 2004/11
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*
Dai-23-Kai Nihon Shimyureshon Gakkai Taikai Happyo Rombunshu, p.121 - 124, 2004/06
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*; Kureta, Masatoshi; Tamai, Hidesada; Akimoto, Hajime
Proceedings of 5th International Conference on Multiphase Flow (ICMF 2004) (CD-ROM), 14 Pages, 2004/06
no abstracts in English
Ose, Yasuo*; Takase, Kazuyuki; Yoshida, Hiroyuki; Kano, Takuma; Kureta, Masatoshi; Akimoto, Hajime
Dai-41-Kai Nihon Dennetsu Shimpojiumu Koen Rombunshu, 2 Pages, 2004/05
no abstracts in English
Ueshima, Yutaka; Kishimoto, Yasuaki
Proceedings of 3rd International Symposium on High Performance Computing, p.524 - 534, 2000/00
no abstracts in English
Matsuoka, Seikichi; Idomura, Yasuhiro; Satake, Shinsuke*
no journal, ,
Effects of non-axisymmetric magnetic field perturbations have attracted much attention from the view point of the control of the plasma performance and instabilities. The perturbations cause the neoclassical toroidal viscosity (NTV) due to the non-ambipolar particle transport. Recent studies pointed out that the qualitative discrepancy of the NTV prediction exist between a theoretical bounce-averaged model and a global kinetic simulation. It is crucial to clarify the cause of the discrepancy to establish a reliable basis for the NTV predictions. In this work, we perform two types of global kinetic simulations for the NTV to investigate the discrepancy from the theoretical model. As a result, it is first demonstrated that the discrepancy arises due to the following two mechanisms; the absence of the magnetic field shear effect in the bounce-averaged model and the so-called transient particle orbit caused by the non-axisymmetric perturbations.
Matsuoka, Seikichi; Idomura, Yasuhiro; Satake, Shinsuke*
no journal, ,
Effects of non-axisymmetric magnetic field perturbations in tokamak devices in which the magnetic field is axisymmetric have attracted much attention. The non-axisymmetric perturbations produces the so-called neoclassical toroidal viscosity (NTV), which is caused by collisional processes in a plasma. The NTV can make influence on the plasma rotation, which plays a key role in controlling a confinement performance and instabilities. Recently, however, it was pointed out that severe discrepancy exists with regard to the evaluation of the NTV between a Superbanana-plateau theory based on the bounce-averaged particle orbit and a global kinetic simulation. Clarifying physical mechanisms that causes the discrepancy is crucial for precise evaluation/prediction of the NTV. In this work, we perform two different types of global kinetic simulations, of which physical and numerical models are quite different from each other to resolve the issue. As a result, it is demonstrated that the discrepancy arises owing to the lack of the following two mechanisms in the theory; (1) insufficient resonance condition with regard to the precession drift, and (2) the transition processes of the particle orbit caused by the non-axisymmetric perturbations.
Matsuoka, Seikichi; Idomura, Yasuhiro; Satake, Shinsuke*
no journal, ,
Effects of non-axisymmetric magnetic field perturbations have attracted much attention from the view point of the control of the plasma performance and instabilities. Recent studies pointed out that the qualitative discrepancy of the NTV prediction exist between a theoretical bounce-averaged model and a global kinetic simulation. It is crucial to clarify the cause of the discrepancy to establish a reliable basis for the NTV predictions. In this work, we perform two types of global kinetic simulations for the NTV to investigate the discrepancy from the theoretical model. As a result, it is first demonstrated that the discrepancy arises owing to the following two mechanisms; (1) resonant structures predicted in the bounce-averaged model disappear due to the large particle orbit in the global kinetic simulations, and (2) fine scale structures are generated in the velocity space in the global kinetic simulations.
Matsuoka, Seikichi; Idomura, Yasuhiro; Satake, Shinsuke*
no journal, ,
Effects of non-axisymmetric magnetic field perturbations caused by error fields and external perturbations have attracted much attention in many axisymmetric tokamak devices such as JT-60 and ITER from the view point of the control of the plasma confinement performance and instabilities. The non-axisymmetric perturbations cause the neoclassical toroidal viscosity (NTV), and establishing a reliable basis for the evaluation/prediction of the NTV becomes important. Recent studies pointed out that the qualitative discrepancy with regard to the evaluation of the NTV exist between a widely-used superbanana-plateau theory based on the bounce-averaged model and a global kinetic simulation. Hence it is crucial to clarify the cause of the discrepancy. In this work, we perform two different types of global kinetic simulations for the NTV to investigate the discrepancy from the theoretical model. As a result, it is first demonstrated that the discrepancy arises owing to the following two mechanisms in the theory; one is the insufficient resonance condition with regard to the precession drift, and the other is the transition processes of the particle orbit caused by the non-axisymmetric perturbations.
Matsuoka, Seikichi; Idomura, Yasuhiro
no journal, ,
Recently, full-f gyrokinetic simulations, in which the total plasma distribution is evolved based on the first principle, attracted much attention in the plasma transport study. Rich physics has been revealed by the simulations in axisymmetric tokamak plasmas such as JT-60 and ITER. However, no full-f gyrokinetic simulations in non-axisymmetric, or three-dimensional magnetic field equilibria such as stellarators and/or helical devices have been reported so far due to their complicated magnetic field geometries which requires more computational resources. In this work, we extend a full-f gyrokinetic simulation code, GT5D, to treat three-dimensional magnetic equilibria by modifying its coordinates, and develop a new interface between GT5D and VMEC, where VMEC is a numerical tool to construct a three-dimensional magnetic equilibria. In the presentation, we present benchmark results as a numerical verification of GT5D+VMEC by comparing the collisional (neoclassical) transport.
Matsuoka, Seikichi; Idomura, Yasuhiro; Satake, Shinsuke*
no journal, ,
Effects of non-axisymmetric magnetic field perturbations in tokamaks have attracted much attention from the view point of the control of the plasma performance and instabilities. Recent studies pointed out that there exists qualitative discrepancy of the NTV prediction between a theoretical bounce-averaged model and a global kinetic simulation. Clarifying the cause of the discrepancy is a key issue to establish a reliable basis for the NTV predictions. In this work, we perform two types of global kinetic simulations for the NTV to investigate the discrepancy from the theoretical model. As a result, it is first demonstrated that the discrepancy arises owing to the following two mechanisms; (1) resonant structures predicted in the bounce-averaged model become weak due to global particle orbit width effects, and (2) the velocity space structures are damped by the phase mixing.
Matsuoka, Seikichi; Idomura, Yasuhiro
no journal, ,
Recently, full-f simulations, in which the gyrokinetic equation is solved for the total plasma distribution function is evolved based on the first principle, attracted much attention in the plasma transport study. Rich physics has been revealed by the simulations in axisymmetric tokamak plasmas such as JT-60 and ITER. However, no full-f gyrokinetic simulations in non-axisymmetric, or three-dimensional magnetic field equilibria such as stellarators and/or helical devices have been reported so far due to their complicated magnetic field geometries which requires more computational resources. In this work, we extend a full-f gyrokinetic simulation code, GT5D, to treat three-dimensional magnetic equilibria by modifying its coordinates, and develop a new interface between GT5D and VMEC, where VMEC is a numerical tool to construct a three-dimensional magnetic equilibria. In the presentation, we give a presentation of the current status of the code development, numerical scheme used in the code, and simulation results.
