A circular equilibrium model for local gyrokinetic simulations of ion temperature gradient fluctuations in reversed field pinches

Journal Article · Sun May 15 04:00:00 EDT 2011 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3581072· OSTI ID:21537806

Tangri, Varun; Terry, P W ^[1]; Waltz, R E ^[2]

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1. Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706R (United States)
2. General Atomics, San Diego, California 92186 (United States)

A simple large-aspect-ratio (R{sub 0}/r) circular equilibrium model is developed for low-beta reversed field pinch (RFP) geometry. The model is suitable for treating small scale instability and turbulent transport driven by ion temperature gradient (ITG) and related electron drift modes in gyrokinetic simulations. The equilibrium model is an RFP generalization of the common tokamak s-{alpha} model to small safety factor (q), where the poloidal field dominates the toroidal field. The model accommodates the RFP toroidal field reversal (where q vanishes) by generalizing the cylindrical force-free Bessel function model (BFM) [J. B. Taylor, Phys. Rev. Lett. 33, 1139 (1974)] to toroidal geometry. The global equilibrium can be described in terms of the RFP field reversal and pinch parameters [F,{Theta}]. This new toroidal Bessel function model (TBFM) has been incorporated into the gyrokinetic code GYRO [J. Candy and R. E. Waltz, J.Comput. Phys. 186, 545 (2003)] and used here to explore local electrostatic ITG adiabatic electron instability rates for typical low-q RFP parameters.

• OSTI ID: 21537806
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 18; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BESSEL FUNCTIONS
CLOSED PLASMA DEVICES
EQUILIBRIUM
FLUCTUATIONS
FUNCTIONS
INSTABILITY
ION TEMPERATURE
PINCH EFFECT
PLASMA INSTABILITY
PLASMA SIMULATION
REVERSE-FIELD PINCH
SIMULATION
TEMPERATURE GRADIENTS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TURBULENCE
VARIATIONS