DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Scale selection and feedback loops for patterns in drift wave-zonal flow turbulence

Journal Article · · Plasma Physics and Controlled Fusion
ORCiD logo [1];  [2];  [3]; ORCiD logo [1];  [4]
  1. Huazhong Univ. of Science and Technology, Wuhan (China)
  2. Univ. of California San Diego, La Jolla, CA (United States)
  3. Univ. of Leeds (United Kingdom)
  4. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

The scale selection and feedback loops for the formation and sustainment of a mesoscopic staircase profile structure are investigated for drift wave-zonal flow turbulence. A mean field model derived from the Hasegawa-Wakatani system and including the evolution of mean density, mean vorticity and perturbed potential enstrophy (PE), is used. Here, it is found that a quasi-periodic zonal staircase forms from self-sharpening of modulation. The principle feedback loop is through the nonlinear dependence of mixing length on electron density gradient, which enters by way of the potential vorticity (PV) gradient. Counterintuitively, E×B shearing is not effective. Moreover, the number of steps in the staircase is sensitive to both the drive (production rate of PE and initial density gradient) and damping (flow viscosity and collisional diffusivity) factors. The minimal step scale is selected by competition between the initial density gradient and diffusive dissipation. Finite turbulence spreading is necessary to form the staircase, but moderate enhancement of turbulence spreading tends to wash out the pattern. The staircase retains a memory of its initial state. Both the mean E×B shear and zonal shear affect the staircase evolution. A strong mean shear quenches the pattern by suppressing the drift wave turbulence. Lastly, the implications of these findings are also discussed.

Research Organization:
Univ. of California, San Diego, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Grant/Contract Number:
FG02-04ER54738
OSTI ID:
1546784
Journal Information:
Plasma Physics and Controlled Fusion, Vol. 61, Issue 10; ISSN 0741-3335
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 13 works
Citation information provided by
Web of Science

References (31)

How is turbulence intensity determined by macroscopic variables in a toroidal plasma? journal September 2013
Bistable dynamics of turbulence spreading in a corrugated temperature profile journal October 2017
How mesoscopic staircases condense to macroscopic barriers in confined plasma turbulence journal November 2016
On the emergence of macroscopic transport barriers from staircase structures journal January 2017
Dynamics of potential vorticity staircase evolution and step mergers in a reduced model of beta-plane turbulence journal April 2019
Turbulence in a strongly stratified fluid—is it unstable? journal January 1972
Dynamics of interfaces and layers in a stratified turbulent fluid journal January 1998
Multiple Jets as PV Staircases: The Phillips Effect and the Resilience of Eddy-Transport Barriers journal March 2008
Long-time asymptotic states of forced two-dimensional barotropic incompressible flows on a rotating sphere journal May 2010
Linear stability of steady zonal jet flows induced by a small-scale forcing on a plane journal November 2011
Weak interaction between zonal jets on a β plane journal July 2012
Double-Diffusive Recipes. Part II: Layer-Merging Events journal May 2014
On the validity of the local diffusive paradigm in turbulent plasma transport journal August 2010
The E × B staircase of magnetised plasmas journal April 2017
$\mathbf{E}\times \mathbf{B}$ staircases and barrier permeability in magnetised plasmas journal November 2016
Finding the Elusive E × B Staircase in Magnetized Plasmas journal February 2015
Identification of Zonal Flows in a Toroidal Plasma journal October 2004
Eddy Motion in the Atmosphere journal January 1915
Turbulence spreading into the linearly stable zone and transport scaling journal April 2004
Plasma Edge Turbulence journal February 1983
Self-organization of electrostatic turbulence in a cylindrical plasma journal October 1987
Multi-device studies of pedestal physics and confinement in the I-mode regime journal July 2016
I-mode: an H-mode energy confinement regime with L-mode particle transport in Alcator C-Mod journal August 2010
Quiescent H-mode plasmas in the DIII-D tokamak journal April 2002
Scaling trends of the critical E   ×   B shear for edge harmonic oscillation onset in DIII-D quiescent H-mode plasmas journal September 2018
From Phase Locking to Phase Slips: A Mechanism for a Quiescent H mode journal April 2015
Excitation Mechanism of Low- n Edge Harmonic Oscillations in Edge Localized Mode-Free, High Performance, Tokamak Plasmas journal April 2019
Transport matrix for particles and momentum in collisional drift waves turbulence in linear plasma devices journal February 2016
Zonal flows in plasma—a review journal April 2005
The ecology of flows and drift wave turbulence in CSDX: A model journal February 2018
Mesoscopic Transport Events and the Breakdown of Fick’s Law for Turbulent Fluxes journal September 2018

Figures / Tables (23)