• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Study of Improved Confinement in Helical Plasmas

Research Project

Project/Area Number 11680501
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Nuclear fusion studies
Research InstitutionNational Institute for Fusion Science

Principal Investigator

ITOH Kimitaka  National Institute for Fusion Science, Professor, 大型ヘリカル研究部, 教授 (50176327)

Co-Investigator(Kenkyū-buntansha) FUJISAWA Akihide  National Institute for Fusion Science, Associate professor, 大型ヘリカル研究部, 助教授 (60222262)
IDA Katsumi  National Institute for Fusion Science, Professor, 大型ヘリカル研究部, 教授 (00184599)
SANUKI Heiji  National Institute for Fusion Science, Associate professor, 大型ヘリカル研究部, 助教授 (80109355)
ITOH Sanae-I  Institute for Applied Mechanics, Kyushu University, Professor, 応用力学研究所, 教授 (70127611)
TODA Shinichiro  National Institute for Fusion Science, Research associate, 大型ヘリカル研究部, 助手 (60332186)
Project Period (FY) 1999 – 2002
Project Status Completed (Fiscal Year 2002)
Budget Amount *help
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2002: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
KeywordsHelical plasmas / electric field interface / radial electric field / bifurcation / transport barrier / self-organized oscillation
Research Abstract

In this research project, a possibility of improved confinement in helical plasmas is investigated, putting an emphasis on the mechanism of "electric field bifurcation and turbulence suppression". In addition, a proposal of experimental test by use of CHS device is examined.
In the analysis, we first study the condition that the electric field interface is realized in helical plasmas. The electric field interface, across which the domains with different electric field polarity contact each other, is associated with the strong gradient of radial electric field. This gradient of electric field could reach the level where the microscopic plasma turbulence could be suppressed. This structure has been predicted to exist, and the issue is to investigate whether it is self-sustained in a stationary state and whether such a stationary state is easily accessible or not.
These problems were studied in this project, by exploring a theoretical model together with the transport simulation code which includes the presence of interface. Theoretical model of microscopic turbulence is combined with the study of interface, and a threshold condition is derived. The self-sustaining mechanism is verified to work in heliotron/torsatron type configurations, and the accessibility to such a state is analyzed in the space of controlling parameters. A phase diagram was obtained. Based on the theoretical framework, experimental studies were performed. It was shown that the electric field interface is possible to occur in CHS so as to suppress the microscopic plasma turbulence. The internal transport barrier for electron energy was also found in W7-AS and LHD devices, confirming the validity of the theoretical model.
Through this project, theory for plasma turbulence, transition and structure formation has been progressed substantially.

Report

(5 results)
  • 2002 Annual Research Report   Final Research Report Summary
  • 2001 Annual Research Report
  • 2000 Annual Research Report
  • 1999 Annual Research Report
  • Research Products

    (49 results)

All Other

All Publications (49 results)

  • [Publications] S.-I.Itoh, K.Itoh, S.Toda: "Probability of Statistical L-H Transition in Tokamaks"Phys.Rev.Lett. 89. 215001 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S Toda, K Itoh: "Modelling of electron root plasmas in helical devices"Plasma Phys.Control. Fusion. 44・5A. A501-A505 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S-I Itoh, A Kitazawa, M Yagi, K Itoh: "Bifurcation and phase diagram of turbulence constituted from three different scale-length modes"Plasma Phys.Control. Fusion. Vol.44,No.6. 1311-1328 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] N Kasuya, K Itoh, Y Takase: "Multiple bifurcation of the radial electric field structure induced by electrodes in tokamaks"Plasma Phys.Control. Fusion. Vol.44No.5A. A287-A292 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S Toda, K Ito: "Theoretical study of the structure of the electric field in helical toroidal plasmas by the use of an anomalous transport model"Plasma Phys.Contr.Fusion. Vol.44,No.3. 325-334 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Kimitaka Itoh, Sanae-I Itoh: "Transient response of transport at transport barrier formation"Plasma Phys.Control. Fusion. Vol.44No.5A. A367-A372 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S-I Itoh, K Itoh, et al.: "Transition in multiple-scale-lengths turbulence in plasmas"Phys.Plasmas. Vol.9No.5. 1947-1954 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] M.Kawasaki, A.Furuya, M.Yagi, K.Itoh, S.-I.Itoh: "Transition probability to turbulent transport regime"Plasma Phys.Control. Fusion. Vol.44No.5A. A473-A478 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] M.Yokoyama, K.Itoh, S.Okamura, K.Matsuoka: "The drift reversal capability in quasi-axisymmetric stellarators"Nucl.Fusion. Vol.42. 1094-1101 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] A.Yoshizawa, S.-I.Itoh, K.Itoh: "Plasma and Fluid Turbulence -Theory and Modelling"Institute of Physics Publishing (Bristol, UK). 459 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S.-I. Itoh, K. Itoh and S. Toda: "Probability of Statistical L-H Transition in Tokamaks"Phys. Rev. Lett.. Vol.89. 215001 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S Toda and K Itoh: "Modelling of electron root plasmas in helical devices"Plasma Phys. Control. Fusion. Vol.44,No.5A. A501-A505 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S-I Itoh, A Kilazawa, M Yagi and K Itoh: "Bifurcation and phase diagram of turbulence constituted from three different scale-length modes"Plasma Phys. Control. Fusion. Vol.44,No.6. 1311-1328 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] N Kasuya, K Itoh and Y Takase: "Multiple bifurcation of the radial electric field structure induced by electrodes in tokamaks"Plasma Phys. Control. Fusion. vol.44,No.5A. A287-A292 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S Toda and K Itoh: "Theoretical study of the structure of the electric field in helical toroidal plasmas by the use of an anomalous transport model"Plasma Phys. Contr. Fusion. Vol.44, No3. 325-334 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] K. Itoh and S.-I Itoh: "Transient response of transport at transport barrier formation"Plasma Phys. Control. Fusion. vol.44,No.5A. A367-A372 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S-I Itoh, K Itoh. et al.: "Transition in multiple-scale-lengths turbulence in plasmas"Phys. Plasmas. vol.9 No.5. 1947-1954 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] M. Kawasaki, A. Furuya, M. Yagi, K. Itoh and S.-I. Itoh: "Transition probability to turbulent transport regime"Plasma Phys. Control. Fusion. Vol.44 No.5A. A473-A478 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] M. Yokoyama, K. Itoh. S. Okamura and K. Matsuoka: "The drift reversal capability in quasi-axisymmetric st ellarators"Nucl. Fusion. Vol.42. 1094-1101 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] A. Yoshizawa, S.-I. Itoh and K. Itoh: "Plasma and Fluid Turbulence - Theory and Modelling"Institute of Physics Publishing (Bristol,UK, 2002). 459 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S.-I.Itoh, K.Itoh, S.Toda: "Probability of Statistical L-H Transition in Tokamaks"Phys.Rev.Lett. 89. 215001 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] S Toda, K Itoh: "Modelling of electron root plasmas in helical devices"Plasma Phys.Control.Fusion. 44・5A. A5001-A505 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] S-I Itoh, A Kitazawa, M Yagi, K Itoh: "Bifurcation and phase diagram of turbulence constituted from three different scale-length modes"Plasma Phys.Control.Fusion. Vol.44, No.6. 1311-1328 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] N Kasuya, K Itoh, Y Takase: "Multiple bifurcation of the radial electric field structure induced by electrodes in tokamaks"Plasma Phys.Control.Fusion. vol.44No.5A. A287-A292 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] S Tod, K Ito: "Theoretical study of the structure of the electric field in helical toroidal plasmas by the use of an anomalous transport model"Plasma Phys.Contr.Fusion. Vol.44, No.3. 325-334 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Kimitaka itoh, Sanae-I Itoh: "Transient response of transport at transport barrier formation"Plasma Phys Control Fusi. vol.44No.5A. A347-A372 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] S-I Itoh, K Itoh, et al.: "Transition in multiple-scale-lengths turbulence in plasmas"Phys Plasmas. vol.9No.5. 1947-1954 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] A Yoshizawa, S-I Itoh, K Itoh: "Plasma and Fluid Turbulence-Theory and Modelling"Institute of Physics Publishing (Bristol, UK). 459 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] K.Itoh, et al.: "Transition of radial electric field in helical systems"J. Phys. Soc. Jpn.. Vol.70. 1575-1584 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] K.Itoh, et al.: "Modelling of density limit phenomena in toroidal helical plasmas"J. Phys. Soc. Jpn.. Vol.70No.11. 3274-3284 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] K.Itoh: "Magnetic structuro and transport (in Japanese), (2001)"J. Plasma and Fusion Research. Vol.77No.2. 125-129 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] U.Stroth, K.Itoh, S.-I.Itoh, et al.: "Internal transport barrier triggered by neoclassical transport in W7-AS"Physical Review Letters. Vol.86, No.26. 5910-5913 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] S.Toda, K.Itoh: "Theoretical Study of the structure of the electric field in helical toroidal plasmas"Czechoslovak Journal of Physics. Vol.51, No.10. 1087-1096 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] S.Toda, K.Itoh: "Theoretical study of the structure of the electric field in helical toroidal plasmas by the use of an anomalous transport model"Plasma Phys. Contr. Fusion. Vol.44, No.3. 325-334 (2002)

    • Related Report
      2001 Annual Research Report
  • [Publications] N.Kasuya, K.Itoh, Y.Takase: "Radial electric field structure between electrodes separated by a finite distance in tokamak plasmas"J. Phys. Soc. Jpn.. Vol.71No.1. 93-98 (2002)

    • Related Report
      2001 Annual Research Report
  • [Publications] K.ITOH, et al.: "On turbulent transport in burning plasmas"Plasma Phys.Contr.Fusion. 42.7. 855-861 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] A.Fujisawa,…,K.ITOH, et al.: "Transport barrier formation and bifurcation patterns of potential in compact helical system heliotron/torsatron"Plasma Phys.Control.Fusion. 42.5. A103-A108 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] M.Yagi,S.-I.Itoh,K.Itoh,A.Fukuyama: "MHD interaction dynamics of shear flow and islands"Plasma Phys.Contr.Fusion. 42.5. A133-A138 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] L.Giannone,…,K.ITOH, et al.: "Physics of density limit in the W7-AS stellarator"Plasma Phys.Contr.Fusion. 42.6. 603-627 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] A.Fujisawa,…,K.ITOH, et al.: "Experimental Study of the bifurcation nature of the electrostatic potential of a toroidal helical plasma"Phys.Plasmas. 7.10. 4152-4183 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] M.Yokoyama,K.ITOH, et al.: "Confirmation of theoretical evaluation of equilibrium current in helical systems."Nucl.Fusion. 40.11. 1909-1916 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] K.L,Wong,K.ITOH, et al.: "Short wavelength fluctuations and electron transport in TFTR"Phys.Letters. A276,Nov6. 281-285 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] A.Yoshizawa,S.-I,ITOH,K.ITOH,N.YOKOI: "Turbulence theories and modelling of fluids and plasmas"Plasma Phys.Contr.Fusion. 43.3. R1-R144 (2001)

    • Related Report
      2000 Annual Research Report
  • [Publications] S.- I. ITOH, K. ITOH: "Statistical Theory of Subcritically-Excited Strong Turbulence in Inhomogeneous Plasmas I"J Phys. Soc. Jpn.. 68・6. 1891-1906 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] S.- I. ITOH, K. ITOH: "Statistical Theory of Subcritically-Excited Strong Turbulence in Inhomogeneous Plasmas II"J Phys. Soc. Jpn.. 68. (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] S.- I. ITOH, K. ITOH: "Statistical Theory of Subcritically-Excited Strong Turbulence in Inhomogeneous Plasmas III"J Phys. Soc. Jpn.. 69・2. 408-426 (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] S.- I. ITOH, K. ITOH: "Statistical Theory of Subcritically-Excited Strong Turbulance in Inhomogeneous Plasmas IV"J Phys. Soc. Jpn.. 69・2. 427-440 (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] S. Toda, S.- I. ITOH, M. YAGI, K. ITOH, A. Fukuyama: "Probabilistic Nature in L/H Transition"J Phys. Soc. Jpn.. 68・11. 3520-3527 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] H. Sanuki, K. ITOH, M. Yokoyama, A. Fujikawa, K. Ida, S.Toda, et al.: "Possibility or Electric Field Bifurcation and Internal Transport Barrier Formation in LHD Plasma"J Phys. Soc. Jpn.. 69・2. 445-450 (2000)

    • Related Report
      1999 Annual Research Report

URL: 

Published: 1999-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi