48 research outputs found
Gyrokinetic simulations of microinstabilities in stellarator geometry
A computational study of microinstabilities in general geometry is presented. The ion gyrokinetic is solved as an initial value problem. The advantage of this approach is the accurate treatment of some important kinetic effects. The magnetohydrodynamic equilibrium is obtained from a three-dimensional local equilibrium model. The use of a local magnetohydrodynamic equilibrium model allows for a computationally-efficient systematic study of the impact of the magnetic structure on microinstabilities
Metamorphosis of plasma turbulence-shear flow dynamics through a transcritical bifurcation
The structural properties of an economical model for a confined plasma
turbulence governor are investigated through bifurcation and stability
analyses. A close relationship is demonstrated between the underlying
bifurcation framework of the model and typical behavior associated with low- to
high-confinement transitions such as shear flow stabilization of turbulence and
oscillatory collective action. In particular, the analysis evinces two types of
discontinuous transition that are qualitatively distinct. One involves
classical hysteresis, governed by viscous dissipation. The other is
intrinsically oscillatory and non-hysteretic, and thus provides a model for the
so-called dithering transitions that are frequently observed. This
metamorphosis, or transformation, of the system dynamics is an important late
side-effect of symmetry-breaking, which manifests as an unusual non-symmetric
transcritical bifurcation induced by a significant shear flow drive.Comment: 17 pages, revtex text, 9 figures comprised of 16 postscript files.
Submitted to Phys. Rev.
Linear dispersion relation of beta-induced Alfvén eigenmodes in presence of anisotropic energetic ions
Physics of the L-H Transition and Type III-ELMs Phenomena (Scaling Properties and Dimensionless Analysis)
The scaling of the giant ELM frequency
SIGLEAvailable from British Library Document Supply Centre-DSC:4672.262(JET-P--(96)24) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
The SOL width and MHD interchange instability in tokamaks
SIGLEAvailable from British Library Document Supply Centre- DSC:4672.262(JET-P--94/44) / BLDSC - British Library Document Supply CentreGBUnited Kingdo