Development of drift-resistive-inertial ballooning transport model for tokamak edge plasmas

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3478979· OSTI ID:21432230

Rafiq, T; Bateman, G; Kritz, A H; Pankin, A Y ^[1]

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1. Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015 (United States)

A new model is developed for transport driven by drift-resistive-inertial ballooning modes (DRIBMs) in axisymmetric tokamak plasmas. The model is derived using two-fluid reduced Braginskii equations in a generalized s-{alpha} geometry. The unified theory includes diamagnetic effects, parallel electron and ion dynamics, electron inertia, magnetic perturbations, transverse particle diffusion, gyroviscous stress terms, electron and ion equilibrium temperature gradients, and temperature perturbations. A mixing length approximation is used to compute electron and ion thermal transport as well as particle fluxes from eigenvalues and eigenvectors of the linearized equations. The prediction for the saturation level is obtained by balancing the DRIBM growth rate against the nonlinear ExB convection. The parametric dependence of DRIBMs is investigated in systematic scans over density gradient, electron and ion temperature gradients, magnetic-q, collision frequency, magnetic shear, and Larmor radius. The DRIBM threshold is determined as a function of the collision frequency and the density and temperature gradients. The transition from DRIBM to the toroidal ion temperature gradient (ITG) mode is observed for small density gradients. For steep density gradients, the effect of ITG on DRIBM is found to be stabilizing. The transport seen in the DRIBM is of a scale that is consistent with the observed experimental anomalous transport, suggesting that the DRIBM mode could be the principle agent responsible for edge transport in Ohmic and L-mode discharges.

• OSTI ID: 21432230
• Journal Information: Physics of Plasmas, Vol. 17, Issue 8; Other Information: DOI: 10.1063/1.3478979; (c) 2010 American Institute of Physics; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BALLOONING INSTABILITY
DIFFUSION
EIGENVECTORS
ELECTRON TEMPERATURE
ELECTRONS
ION TEMPERATURE
PLASMA DRIFT
TEMPERATURE GRADIENTS
TOKAMAK DEVICES
CLOSED PLASMA DEVICES
ELEMENTARY PARTICLES
FERMIONS
INSTABILITY
LEPTONS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR DEVICES