Quasilinear model for energetic particle diffusion in radial and velocity space

Journal Article · Mon Apr 15 04:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4802808· OSTI ID:22130451

Waltz, R. E.; Staebler, G. M. ^[1]; Bass, E. M. ^[2]

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1. General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)
2. University of California-San Diego, 9500 Gilman Dr., La Jolla, California 92093 (United States)

A quasilinear model for passive energetic particle (EP) turbulent diffusion in radial and velocity space is fitted and tested against nonlinear gyrokinetic tokamak simulations with the GYRO code [J. Candy and R. E. Waltz, Phys. Rev. Lett. 91, 045001 (2003)]. Off diagonal elements of a symmetric positive definite 2 Multiplication-Sign 2 EP diffusion matrix account for fluxes up radial (energy) gradients driven by energy (radial) gradients of the EP velocity space distribution function. The quasilinear ratio kernel of the model is provided by a simple analytic formula for the EP radial and velocity space EP diffusivity relative to radial thermal ion energy diffusivity at each linear mode of the turbulence driven by the thermal plasma. The TGLF [G. M. Staebler, J. E. Kinsey, and R. E. Waltz, Phys. Plasmas 14, 0055909 (2007); ibid. 15, 0055908 (2008)] tokamak transport model provides the linear mode frequency and growth rates to the kernel as well as the nonlinear spectral weight for each mode.

• OSTI ID: 22130451
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DIFFUSION
DISTRIBUTION FUNCTIONS
KINETIC ENERGY
NONLINEAR PROBLEMS
PLASMA
PLASMA CONFINEMENT
PLASMA SIMULATION
TOKAMAK DEVICES
TRANSPORT THEORY
TURBULENCE
VELOCITY