Geodesic acoustic mode oscillation in the low frequency range
نویسندگان
چکیده
منابع مشابه
Energetic-particle-induced geodesic acoustic mode.
A new energetic particle-induced geodesic acoustic mode (EGAM) is shown to exist. The mode frequency and mode structure are determined nonperturbatively by energetic particle kinetic effects. In particular the EGAM frequency is found to be substantially lower than the standard GAM frequency. The radial mode width is determined by the energetic particle drift orbit width and can be fairly large ...
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Linear Properties and nonlinear frequency chirping of energetic particle driven geodesic acoustic mode (EGAM) is investigated using a hybrid simulation code for energetic particles interacting with a magnetohydrodynamic fluid. It is found that the EGAM is a global mode with the spatially uniform oscillation frequency. The poloidal mode numbers of poloidal velocity fluctuation, plasma density fl...
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Geodesic Acoustic Modes (GAM) are known to constitute a continuous spectrum due to radial inhomogeneities. The existence of a singular layer causes GAM to mode convert to short wavelength kinetic GAM (KGAM) via finite ion Larmor radius (FLR) and finite guiding-center drift-orbit-width (FOW) effects. The dispersion relation of GAM/KGAM with FLR/FOW as well as parallel electric field contribution...
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Experimental investigations has elucidated on the complex dynamics of the low to high (L-H) plasma confinement mode transition. Evidence of interactions between the the turbulence driven E⃗ × B⃗ zonal flow oscillation or Geodesic Acoustic Mode (GAM) [1], turbulence and the mean equilibrium flows during this transition was found. Furthermore, periodic modulation of flow and turbulence level with t...
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Stable operation in a single mode is an important goal of high-power gyrotrons. Both multimoding and switching into ynwanted modes can lead to lower efficiency and undesirable heating of components not designed to accommodate parasitic modes. We have extensively studied mode behavior in a pulsed 100-kW, 140-GHz gyrotron using a variety of mixing techniques. As a result, a number of multimoding ...
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ژورنال
عنوان ژورنال: Physics of Plasmas
سال: 2006
ISSN: 1070-664X,1089-7674
DOI: 10.1063/1.2206170