Dynamically stable, self-similarly evolving, and self-organized states of high beta tokamak and reversed pinch plasmas and advanced active control

Kondoh, Yoshiomi; Fukasawa, Toshinobu
November 2009
Physics of Plasmas;Nov2009, Vol. 16 Issue 11, p112504
Academic Journal
Generalized simultaneous eigenvalue equations derived from a generalized theory of self-organization are applied to a set of simultaneous equations for two-fluid model plasmas. An advanced active control by using theoretical time constants is proposed by predicting quantities to be controlled. Typical high beta numerical configurations are presented for the ultra low q tokamak plasmas and the reversed-field pinch (RFP) ones in cylindrical geometry by solving the set of simultaneous eigenvalue equations. Improved confinement with no detectable saw-teeth oscillations in tokamak experiments is reasonably explained by the shortest time constant of ion flow. The shortest time constant of poloidal ion flow is shown to be a reasonable mechanism for suppression of magnetic fluctuations by pulsed poloidal current drives in RFP experiments. The bifurcation from basic eigenmodes to mixed ones deduced from stability conditions for eigenvalues is shown to be a good candidate for the experimental bifurcation from standard RFP plasmas to their improved confinement regimes.


Related Articles

  • Guiding center particle simulation of wide-orbit neoclassical transport. Bergmann, A.; Peeters, A. G.; Pinches, S. D. // Physics of Plasmas;Dec2001, Vol. 8 Issue 12, p5192 

    The neoclassical ion transport in a tokamak plasma with circular cross section is studied with guiding center particle simulations. A Monte Carlo model of pitch-angle scattering which includes momentum conservation is employed. The model includes the whole plasma inside closed flux surfaces, but...

  • A drift-magnetohydrodynamical fluid model of helical magnetic island equilibria in the pedestals of H-mode tokamak plasmas. Fitzpatrick, R.; Waelbroeck, F. L. // Physics of Plasmas;Jun2010, Vol. 17 Issue 6, p062503 

    A drift-magnetohydrodynamical (MHD) fluid model is developed for an isolated, steady-state, helical magnetic island chain, embedded in the pedestal of a large aspect ratio, low-β, circular cross section, H-mode tokamak plasma, to which an externally generated, multiharmonic, static magnetic...

  • A new eigenvalue problem associated with the two-dimensional Newcomb equation without continuous... Tokuda, Shinji; Watanabe, Tomoko // Physics of Plasmas;Aug99, Vol. 6 Issue 8, p3012 

    Reports on an eigenvalue problem associated with the two-dimensional Newcomb equation in an axisymmetric toroidal plasma like a tokamak. Formulation of the eigenvalue problem where the weight functions are chosen; Singular behavior predicted by the theory of rational surfaces.

  • Stability of resistive and ideal ballooning modes in the Texas Experimental Tokamak and DIII-D. McCarthy, D. R.; Guzdar, P. N.; Drake, J. F.; Antonsen, T. M.; Hassam, A. B. // Physics of Fluids B: Plasma Physics;Jul92, Vol. 4 Issue 7, p1846 

    The stability of drift resistive ballooning modes is examined using the reduced Braginskii equations, which include electron temperature and magnetic fluctuations. The Texas Experimental Tokamak (TEXT) [Phys. Fluids B 2, 2879 (1990)] edge plasma is found to be unstable for a broad range of mode...

  • TFTR Mirnov loop system. Fredrickson, E.; Colchin, R.; McGuire, K.; Morris, W.; Sauthoff, N. // Review of Scientific Instruments;Aug1986, Vol. 57 Issue 8, p2084 

    Magnetic pick-up loops (Mirnov coils) located on the inner wall of the tokamak fusion test reactor (TFTR) vacuum vessel have been used to study magnetic fluctuations in the plasma. To study the high-frequency magnetic turbulence associated with beam injection, the signal from one coil is passed...

  • Resistive edge mode instability in stellarator and tokamak geometries. Mahmood, M. Ansar; Rafiq, T.; Persson, M.; Weiland, J. // Physics of Plasmas;Sep2008, Vol. 15 Issue 9, p092507 

    Geometrical effects on linear stability of electrostatic resistive edge modes are investigated in the three-dimensional Wendelstein 7-X stellarator [G. Grieger et al., Plasma Physics and Controlled Nuclear Fusion Research 1990 (International Atomic Energy Agency, Vienna, 1991), Vol. 3, p. 525]...

  • A drift ordered short mean free path description for magnetized plasma allowing strong spatial anisotropy. Catto, Peter J.; Simakov, Andrei N. // Physics of Plasmas;Jan2004, Vol. 11 Issue 1, p90 

    Short mean free path descriptions of magnetized plasmas have existed for almost 50 years so it is surprising to find that further modifications are necessary. The earliest work adopted an ordering in which the flow velocity is assumed to be comparable to the ion thermal speed. Later, less...

  • Plasma-particulate interactions in nonuniform plasmas with finite flows. Hamaguchi, S.; Farouki, R.T. // Physics of Plasmas;Jul94, Vol. 1 Issue 7, p2110 

    Discusses the derivation of the polarization force on a charged particulate or dust grain in a nonuniform plasma with finite ion flows and an external electric field. Proportion of the polarization force to the magnitude of the spatial gradient of the Debye length; Expressions describing the...

  • Measuring the ion current in high-density plasmas using radio-frequency current and voltage measurements. Sobolewski, Mark A. // Journal of Applied Physics;9/15/2001, Vol. 90 Issue 6 

    The total current or flux of ions striking the substrate is an important parameter that must be tightly controlled during plasma processing. Several methods have recently been proposed for monitoring the ion current in situ. These methods rely on passive, noninvasive measurements of the radio...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics