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2009
Tearing mode stability is normally analysed using MHD or two-fluid Braginskii plasma models. However for present, or future, large hot tokamaks like JET or ITER the collisionality is such as to place them in the banana regime. Here we develop a linear stability theory for the resonant layer physics appropriate to such a regime. The outcome is a set…
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2009
The stability of ion temperature gradient ITG modes and the quasilinear fluxes driven by them are analyzed in weakly collisional tokamak plasmas using a semianalytical model based on an approximate solution of the gyrokinetic equation, where collisions are modeled by a Lorentz operator. Although the frequencies and growth rates of ITG modes far fro…
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2009
Self-consistent computations are carried out to study the stability of the resistive wall mode RWM in DIII-D J. L. Luxon, Nucl. Fusion 42 , 614 2002 plasmas with slow plasma rotation, using the hybrid kinetic-magnetohydrodynamic code MARS-K [Y. Q. Liu and et al. , Phys. Plasmas 15 , 112503 (2008)]. Based on kinetic resonances between the mode and t…
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2009
The generation of zonal magnetic fields in laboratory fusion plasmas is predicted by theoretical and numerical models and was recently observed experimentally. It is shown that the modification of the current density gradient associated with such corrugations can significantly affect the stability of the tearing mode. A simple scaling law is derive…
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2009
Experiments have been performed on MAST using both external (n=1,2) and internal (n=3) resonant magnetic perturbation coils. ELM suppression has not been achieved even though vacuum modelling shows that either set of coils can produce a region for which the Chirikov parameter is greater than 1 wider than that required to produce ELM suppression in …
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2009
This workshop on transport in fusion plasmas is the thirteenth in a series. Previously they have been held under the auspices of the EU and US Transport Task Forces (TTFs), with J Connor as the EU TTF chair. However, the EU Transport Task Force has now been subsumed into the EFDA (European Fusion Development Agreement) Topical Group for Transport (…
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2009
We investigate drift kinetic effects on the resistive wall mode (RWM) stability in ITER plasmas, due to the mode resonance with magnetic precession drifts and/or bounce motion of bulk plasma thermal particles. A toroidal drift kinetic model is self-consistently incorporated into the MHD formulation. Self-consistent simulations using the hybrid kine…
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2009
‘Advanced tokamak’ (AT) scenarios were developed with the aim of reaching tokamak steady-state operation. They are designed to optimise the self-generated current, whilst also reaching sufficiently high plasma pressure to achieve optimal fusion reaction rates. AT scenarios exhibit non-monotonic to flat safety factor profiles (q, a measure of th…
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2008
A new analytically and numerically manageable model collision operator is developed specifically for turbulence simulations. The like-particle collision operator includes both pitch-angle scattering and energy diffusion and satisfies the physical constraints required for collision operators: it conserves particles, momentum, and energy, obeys Boltz…
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2008
A self-consistent kinetic model is developed to study the stability of the resistive wall mode in toroidal plasmas. This model is compared with other models based on perturbative approaches. The degree of the kinetic modification to the stability of the mode depends on the plasma configurations. Both stabilizing and destabilizing kinetic effects ar…
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