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CLM P1031966
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CLM P851965
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CLM P791965
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CCFE-PR(15)1082015
Landau’s calculation of electron plasma oscillations demonstrated the phenomenon now known as Landau damping.1 The calculation used a Fourier-Laplace transform and regarded the electron velocity as complex in order to properly locate the pole in the complex frequency plane that gives the dispersion relation containing the wave damping. Here, the …
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1999
A uniform compressible plasma with a uniform flow along the magnetic field in the presence of a resistive wall is shown to be subject to two instabilities. For the first instability, the flow velocity is required to exceed the Alfve´n speed, whereas for the second it need only exceed the sound speed. For a sufficiently high ion temperature, ion La…
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1999
Tokamaks exhibit several types of relaxation oscillations such as sawteeth, fishbones and Edge Localized Modes (ELMs) under appropriate conditions. Several authors have introduced model nonlinear dynamic systems with a small number of degrees of freedom which can illustrate the generic characteristics of such oscillations. In these models, one focu…
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1996
Advanced Tokamak Concepts [C. Kessel, J. Manickam, G. Rewoldt, and W. M. Tang, Phys. Rev. Lett. 72 , 1212 (1994)] have been designed assuming that the ‘‘Resistive Wall Mode’’ (RWM) is stable. It has recently been shown that the RWM can be stabilized by a combination of strong uniform plasma rotation and visco-resistive dissipation. In this …
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1993
Both neoclassical theory and certain turbulence theories of particle transport in tokamaks predict the existence of bootstrap (i.e., pressure-driven) currents. Two new applications of this form of noninductive current are considered in this work. In the first, an earlier model of the nonlinearly saturated m= 1 tearing mode is extended to include th…
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1992
This Brief Communication investigates the influence of toroidal effects (due to the coupling of various poloidal harmonics) on the nonlinear saturation of the m = 1 island. Bounds are obtained relating the aspect ratio, the shear at the q= 1 surface, and the saturated island width. Provided these bounds are satisfied, it is then found that the cyli…
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1991
The purpose of this paper is to investigate the possible relationships between transport properties such as thermal diffusivity and resistivity on the one hand, and the magnetic properties such as q profile and toroidal flux change on the other, in tokamaks that exist under macroscopically quasistationary conditions. It is experimentally well estab…
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