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1999
Ion cyclotron emission (ICE) excited by collective instability of fusion a particles has been observed during deuterium-tritium experiments with radio-frequency heating and neutral beam injection (NBI) in the Joint European Torus. A model based on classical a-particle confinement is broadly consistent with this data. ICE spectra from discharges wit…
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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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1999
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1998
The Small Tight Aspect Ratio Tokamak (START) [A. Sykes et al., Nucl. Fusion 32, 769 (1994)] spherical tokamak has recently achieved the record value of toroidal beta~30% in a tokamak-like configuration. The improvements that have made these results possible are presented along with a description of the global equilibrium parameters of the discharge…
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1998
This paper and a forthcoming one develop the spectral theory of ballooning transformations relevant to tokamak physics from rst principles in a rigorous and yet intuitively clear manner. The power of the ballooning representation to throw light on the spectral characteristics of the plasma problems to which it is applicable is emphasized, and examp…
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1997
A cylindrical model of a tokamak is used to describe the nonlinear coupling between Alfven waves and sound waves. The model is applied to the case of a toroidal Alfven eigenmode (TAE) driven unstable by fusion alpha particles to explore its relevance to the nonlinear saturation of such modes, which can produce a loss of alpha particles in a burning…
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1997
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1996
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1995
Ion cyclotron emission ~ ICE ! has been observed during neutral beam-heated supershots in the Tokamak Fusion Test Reactor ~ TFTR ! @ Phys. Rev. Lett. 72 , 3526 ~ 1994 !# deuterium–tritium campaign at fusion product cyclotron harmonics. The emission originates from the outer midplane edge plasma, where fusion products initially have an anisotropic…
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1995
A generalized energy principle is used to determine the effect of ion cyclotron resonant heating (lCRH) on the stability of m = 1 intemal kink displacements in the low-frequency limit: such displacements are associated with sawtooth oscillations. An integral expression is obtained for the contribution to the plasma energy of an ICRH-heated minority…
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