Phenomenology of compressional Alfvén eigenmodes

Fredrickson, E.D.; Gorelenkov, N.N.; Menard, J.
July 2004
Physics of Plasmas;Jul2004, Vol. 11 Issue 7, p3653
Academic Journal
Coherent oscillations with frequency 0.3≤ω/ωci≤1, are seen in the National Spherical Torus Experiment [M. Ono, S. M. Kaye, Y.-K. M. Peng et al., Nucl. Fusion 40, 557 (2000)]. This paper presents new data and analysis comparing characteristics of the observed modes to the model of compressional Alfvén eigenmodes (CAE). The toroidal mode number has been measured and is typically between 7<n<9. The polarization of the modes, measured using an array of four Mirnov coils, is found to be compressional. The frequency scaling of the modes agrees with the predictions of a numerical two-dimensional code, but the detailed structure of the spectrum is not captured with the simple model. The fast ion distribution function, as calculated with the beam deposition code in TRANSP [R. V. Budny, Nucl. Fusion 34, 1247 (1994)], is shown to be qualitatively consistent with the constraints of the Doppler-shifted cyclotron resonance drive model. This model also predicts the observed scaling of the low frequency limit for CAE. © 2004 American Institute of Physics.


Related Articles

  • On spectral expansions of piecewise smooth functions depending on the geodesic distance. Alimov, Sh. // Differential Equations;Jun2010, Vol. 46 Issue 6, p827 

    We consider the expansion of a piecewise smooth function depending on the geodesic distance to some point in the eigenfunctions of the Beltrami-Laplace operator on an n-dimensional symmetric space of rank 1. We show that if the expansion converges at this point, then the function must have...

  • Basis property of eigenfunctions of the Frankl problem with a nonlocal evenness condition and with a discontinuity in the solution gradient. Moiseev, E. I.; Abbasi, N. // Differential Equations;Oct2008, Vol. 44 Issue 10, p1460 

    In the present paper, we write out the eigenfunctions of the Frankl problem with a nonlocal evenness condition and with a discontinuity of the normal derivative of the solution on the line of change of type of the equation. We show that these eigenfunctions form a Riesz basis in the elliptic...

  • Problem on multiple eigenvalues and positive eigenfunctions for a one-dimensional second-order quasilinear equation. Kostomarov, D.; Sheina, E. // Differential Equations;Aug2012, Vol. 48 Issue 8, p1081 

    We consider the eigenvalue and eigenfunction problem for a one-dimensional secondorder quasilinear differential equation. We analyze a number of versions of the function f specifying the nonlinearity for which the problem has multiple eigenvalues.

  • Spectral analysis of the Redge problem. Shkalikov, A. // Journal of Mathematical Sciences;Jul2007, Vol. 144 Issue 4, p4292 

    The article studies the properties of the eigenfunctions of the Redge problem. The characteristic determinant and the operator treatment of the problem were explained. All eigenvalues were assumed to be simple to avoid complicating the presentation of the problem with technical details. The...

  • On a Spectral Problem Arising in a Mathematical Model of Torsional Vibrations of a Rod with Pulleys at the Ends. Kapustin, N. // Differential Equations;Oct2005, Vol. 41 Issue 10, p1490 

    The article analyzes a spectral problem arising in a mathematical model of torsional vibrations of a rod with pulleys at the ends. The well-known mathematical model describing small torsional vibrations of a rod consists of the wave equation for the rod rotation angle and the corresponding...

  • ON THE DYNAMIC BEHAVIOR AND STABILITY OF CONTROLLED CONNECTED RAYLEIGH BEAMS UNDER POINTWISE OUTPUT FEEDBACK. Bao-Zhu Guo; Jun-Min Wang; Cui-Lian Zhou // ESAIM: Control, Optimisation & Calculus of Variations;Jul2008, Vol. 14 Issue 3, p632 

    We study the dynamic behavior and stability of two connected Rayleigh beams that are subject to, in addition to two sensors and two actuators applied at the joint point, one of the actuators also specially distributed along the beams. We show that with the distributed control employed, there is...

  • Sungular perturbations of powers of the laplacian on the torus. Belyaev, A. // Mathematical Notes;Sep2013, Vol. 94 Issue 3/4, p594 

    The article presents information on perturbation of powers of the Laplace operator that has been defined on the torus. It has been aimed to carry over theorems on Bessel potential spaces in multiplier spaces. It has been proved that the system of eigenfunctions as well as associated functions of...

  • Spectral singularities for non-Hermitian one-dimensional Hamiltonians: Puzzles with resolution of identity. Andrianov, A. A.; Cannata, F.; Sokolov, A. V. // Journal of Mathematical Physics;May2010, Vol. 51 Issue 5, p052104 

    We examine the completeness of biorthogonal sets of eigenfunctions for non-Hermitian Hamiltonians possessing a spectral singularity. The correct resolutions of identity are constructed for deltalike and smooth potentials. Their form and the contribution of a spectral singularity depend on the...

  • Localized eigenfunctions in Sˇeba billiards. Keating, J. P.; Marklof, J.; Winn, B. // Journal of Mathematical Physics;Jun2010, Vol. 51 Issue 6, p062101 

    We describe some new families of quasimodes for the Laplacian perturbed by the addition of a potential formally described by a Dirac delta function. As an application, we find, under some additional hypotheses on the spectrum, subsequences of eigenfunctions of Sˇeba billiards that localize...


Read the Article


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

Try another library?
Sign out of this library

Other Topics