TITLE

Turbulence-driven zonal flows in helical systems with radial electric fields

AUTHOR(S)
Sugama, H.; Watanabe, T.-H.
PUB. DATE
May 2009
SOURCE
Physics of Plasmas;May2009, Vol. 16 Issue 5, p056101
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Collisionless long-time responses of the zonal-flow potential to the initial condition and turbulence source in helical systems having radial electric fields are derived theoretically. All classes of particles in passing, toroidally trapped, and helical-ripple-trapped states are considered. The transitions between the toroidally trapped and helical-ripple-trapped states are taken into account while solving the gyrokinetic equation analytically by taking its average along the particle orbits. When the radial displacements of helical-ripple-trapped particles are reduced either by neoclassical optimization of the helical geometry lowering the radial drift or by strengthening the radial electric field Er to boost the poloidal rotation, enhanced zonal-flow responses are obtained. Under the identical conditions on the magnitude of Er and the magnetic geometry, using ions with a heavier mass gives rise to a higher zonal-flow response, and therefore the turbulent transport is expected to show a more favorable ion-mass dependence than the conventional gyro-Bohm scaling.
ACCESSION #
40637959

 

Related Articles

  • Weakly turbulent electron cloud transport in a plasma with an external electric field. Kontar, E. P.; Mel’nik, V. N. // Physics of Plasmas;Jul2003, Vol. 10 Issue 7, p2732 

    The propagation of a fast electron cloud in a relatively cold and dense plasma in an electric field is investigated in the framework of weak turbulence theory. The dynamics of an electron cloud in the external electric field is studied both analytically and numerically. It is shown that...

  • Alfvén continuum deformation by kinetic geodesic effect in rotating tokamak plasmas. Elfimov, A. G. // Physics of Plasmas;Feb2010, Vol. 17 Issue 2, p022102 

    Using a quasitoroidal set of coordinates with coaxial circular magnetic surfaces, Vlasov equation is solved for collisionless plasmas in drift approach and a perpendicular dielectric tensor is found for large aspect ratio tokamaks in a low frequency band. Taking into account plasma rotation and...

  • Synergy between ion temperature gradient turbulence and neoclassical processes in global gyrokinetic particle-in-cell simulations. Vernay, T.; Brunner, S.; Villard, L.; McMillan, B. F.; Jolliet, S.; Tran, T. M.; Bottino, A. // Physics of Plasmas;Apr2012, Vol. 19 Issue 4, p042301 

    Based on the CYCLONE case, simulations of collisional electrostatic ion temperature gradient (ITG) microturbulence carried out with the global gyrokinetic particle-in-cell (PIC) code ORB5 are presented. Considering adiabatic electrons, an increase in ion heat transport over the collisionless...

  • Formation of an Effective Electric Field in Track Regions During the Stopping of Fast Heavy Charged Particles in Materials. Metelkin, E. V.; Ryazanov, A. I. // Journal of Experimental & Theoretical Physics;Feb2000, Vol. 90 Issue 2, p370 

    A microscopic approach is used to study the formation of an electric field near the trajectories of fast heavy charged particles propagating in various materials. The analysis is based on determining the space-time distribution function of the fast δ-electrons generated when heavy ions are...

  • Runaway electron production during intense electron beam penetration in dense plasma. Parks, P. B.; Cowan, T. E. // Physics of Plasmas;Jan2007, Vol. 14 Issue 1, p013102 

    Relativistic electrons are efficiently generated when multiterawatt lasers focused to ultrahigh intensities >=1019 W/cm2 illuminate the surface of dense plasma targets. A theoretical study finds that during typical picosecond pulse widths, significant amounts of Dreicer produced runaway...

  • Microwave Excitation In ECRIS plasmas. Ciavola, G.; Barbarino, S.; Catalano, R. S.; Celona, L.; Consoli, F.; Gammino, S.; Maimone, F.; Mascali, D.; Tumino, L. // AIP Conference Proceedings;9/15/2007, Vol. 933 Issue 1, p497 

    A number of phenomena related to the electron cyclotron resonance ion sources (ECRIS) has been better understood recently by means of the improvement of comprehension of the coupling mechanism between microwave generators and ECR plasma. In particular, the two frequency heating and the frequency...

  • One-dimensional Vlasov simulation of parallel electric fields in two-electron population plasma. Saharia, K.; Goswami, K. S. // Physics of Plasmas;Sep2007, Vol. 14 Issue 9, p092302 

    One-dimensional Vlasov simulation in electron current carrying multicomponent plasma seeded with a density depression is presented. Considering two electron populations [one is sufficiently hot (∼keV) and the other is cold along with cold background ions], the formation of weak double...

  • Solution of the equation of continuity for ions moving in a gas under the action of a periodic asymmetric alternating waveform. Buryakov, I. A. // Technical Physics Letters;Jan2006, Vol. 32 Issue 1, p67 

    The motion of ions in a gas under the action of a periodic asymmetric waveform of alternating polarity is theoretically analyzed based on a solution to the equation of continuity. Solutions to the transfer equation describing the ion density distributions in the gas filling planar and...

  • Chemistry of sprite discharges through ion-neutral reactions. Hiraki, Y.; Kasai, Y.; Fukunishi, H. // Atmospheric Chemistry & Physics Discussions;2008, Vol. 8 Issue 1, p2311 

    We estimate the concentration changes, caused by a single streamer in sprites, of ozone and related minor species as odd nitrogen (NOx) and hydrogen (HOx) families in the upper stratosphere and mesosphere. The streamer has an intense electric field and high electron density at its head where a...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

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

Try another library?
Sign out of this library

Other Topics