Abstract Details
Abstracts
Author: Michael Nastac
Requested Type: Poster
Submitted: 2019-02-22 16:44:26
Co-authors: W. Dorland, I.G. Abel
Contact Info:
University of Maryland, College Park
Department of Mathematics
College Park, 20740
United States
Abstract Text:
We analytically and numerically investigate stochastically forced kinetic Langevin equations to probe various phase mixing mechanisms, including parallel free-streaming, curvature drifts, grad-B drifts, and ExB drifts. For phase mixing along the guide field (i.e. Landau damping), we benchmark against the results of [1]. For curvature and grad-B drifts, we derive fluctuation-dissipation relations to find statistically steady-state solutions of the distribution of free energy in the moments of the perturbed distribution function. In the case of the ExB drift (nonlinear perpendicular phase mixing), we find the corresponding Laguerre representation of the Hankel space spectra derived in [2] and compare to simulations. Applications discussed include closures, preconditioners, and phase mixing benchmarks for gyrokinetic codes.
[1] A. Kanekar, et al., Journal of Plasma Physics 81(1), 305810104 (2015)
[2] G. Plunk, et al., Journal of Fluid Mechanics, 664:407–435 (2010)
Comments:
