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Title: The ecology of flows and drift wave turbulence in CSDX: A model

Abstract

This paper describes the ecology of drift wave turbulence and mean flows in the coupled drift-ion acoustic wave plasma of a CSDX linear device. A 1D reduced model that studies the spatiotemporal evolution of plasma mean density $$\bar{n}$$, and mean flows $$\bar{v}$$y and $$\bar{v}$$z, in addition to fluctuation intensity ε, is presented. Here, ε = n ~ 2 + ( Φ ~ ) 2 + v ~ z 2 is the conserved energy field. The model uses a mixing length l mix inversely proportional to both axial and azimuthal flow shear. This form of l mix closes the loop on total energy. The model self-consistently describes variations in plasma profiles, including mean flows and turbulent stresses. It investigates the energy exchange between the fluctuation intensity and mean profiles via particle flux n ~ v ~ x and Reynolds stresses v ~ x v ~ y and v ~ x v ~ z Acoustic coupling breaks parallel symmetry and generates a parallel residual stress Π res xz . The model uses a set of equations to explain the acceleration of $$\bar{v}_y$$ and $$\bar{v}_z$$ via Π x y r e s n - and Π x y r e s n - . Flow dynamics in the parallel direction are related to those in the perpendicular direction through an empirical coupling constant σVT. This constant measures the degree of symmetry breaking in the 〈$$k_mk_z$$〉 correlator and determines the efficiency of ∇$$\bar{n}$$ in driving $$\bar{v}_z$$. The model also establishes a relation between ∇$$\bar{v}_y$$ and ∇$$\bar{v}_z$$, via the ratio of the stresses Π res xy and Π res xz . When parallel to perpendicular flow coupling is weak, axial Reynolds power P x z R e = - v ~ x v ~ z v - z is less than the azimuthal Reynolds power P x y R e = - v ~ x v ~ y v - y ∇$$\bar{v}_y$$. The model is then reduced to a 2-field predator/prey model where $$\bar{v}_z$$ is parasitic to the system and fluctuations evolve self-consistently. Finally, turbulent diffusion in CSDX follows the scaling: D CSDX = D B ρ * 0.6 , where D B is the Bohm diffusion coefficient and ρ * is the ion gyroradius normalized to the density gradient | n - / n - | - 1

Authors:
 [1];  [2];  [3]
  1. Univ. of California, San Diego, CA (United States). Center for Energy Research
  2. Univ. of California, San Diego, CA (United States). Center for Energy Research, Center for Astrophysics and Space Sciences; Center for Fusion Sciences, Southwestern Inst. of Physics, Chengdu, Sichuan (China)
  3. Univ. of California, San Diego, CA (United States). Center for Energy Research; Center for Fusion Sciences, Southwestern Inst. of Physics, Chengdu, Sichuan (China)
Publication Date:
Research Org.:
Univ. of California, San Diego, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1524572
Alternate Identifier(s):
OSTI ID: 1420214
Grant/Contract Number:  
FG02-04ER54738
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 25; Journal Issue: 2; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Hajjar, R. J., Diamond, P. H., and Tynan, G. R. The ecology of flows and drift wave turbulence in CSDX: A model. United States: N. p., 2018. Web. doi:10.1063/1.5018320.
Hajjar, R. J., Diamond, P. H., & Tynan, G. R. The ecology of flows and drift wave turbulence in CSDX: A model. United States. doi:10.1063/1.5018320.
Hajjar, R. J., Diamond, P. H., and Tynan, G. R. Thu . "The ecology of flows and drift wave turbulence in CSDX: A model". United States. doi:10.1063/1.5018320. https://www.osti.gov/servlets/purl/1524572.
@article{osti_1524572,
title = {The ecology of flows and drift wave turbulence in CSDX: A model},
author = {Hajjar, R. J. and Diamond, P. H. and Tynan, G. R.},
abstractNote = {This paper describes the ecology of drift wave turbulence and mean flows in the coupled drift-ion acoustic wave plasma of a CSDX linear device. A 1D reduced model that studies the spatiotemporal evolution of plasma mean density $\bar{n}$, and mean flows $\bar{v}$y and $\bar{v}$z, in addition to fluctuation intensity ε, is presented. Here, ε=〈n~2+(∇⊥Φ~)2+v~z2〉 is the conserved energy field. The model uses a mixing length lmix inversely proportional to both axial and azimuthal flow shear. This form of lmix closes the loop on total energy. The model self-consistently describes variations in plasma profiles, including mean flows and turbulent stresses. It investigates the energy exchange between the fluctuation intensity and mean profiles via particle flux 〈n~v~x〉 and Reynolds stresses 〈v~xv~y〉 and 〈 v~xv~z〉 Acoustic coupling breaks parallel symmetry and generates a parallel residual stress Π res xz . The model uses a set of equations to explain the acceleration of $\bar{v}_y$ and $\bar{v}_z$ via Πxyres∝∇n- and Πxyres∝∇n-. Flow dynamics in the parallel direction are related to those in the perpendicular direction through an empirical coupling constant σVT. This constant measures the degree of symmetry breaking in the 〈$k_mk_z$〉 correlator and determines the efficiency of ∇$\bar{n}$ in driving $\bar{v}_z$. The model also establishes a relation between ∇$\bar{v}_y$ and ∇$\bar{v}_z$, via the ratio of the stresses Π res xy and Π res xz . When parallel to perpendicular flow coupling is weak, axial Reynolds power PxzRe=-〈v~xv~z〉∇v-z is less than the azimuthal Reynolds power PxyRe=-〈v~xv~y〉∇v-y∇$\bar{v}_y$. The model is then reduced to a 2-field predator/prey model where $\bar{v}_z$ is parasitic to the system and fluctuations evolve self-consistently. Finally, turbulent diffusion in CSDX follows the scaling: DCSDX=DBρ*0.6, where DB is the Bohm diffusion coefficient and ρ* is the ion gyroradius normalized to the density gradient |∇n-/n-|-1},
doi = {10.1063/1.5018320},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 2,
volume = 25,
place = {United States},
year = {2018},
month = {2}
}

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Cited by: 3 works
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Figures / Tables:

FIG. 1 FIG. 1: A schematic of the ecology of drift wave turbulence, zonal, and axial flows. The first feedback loop relates the drift waves to the zonal flows via (~vx~vy). A second feedback loop exists as a result of a potential relation between $\bar{v}$y and $\bar{v}$z. The second loop relates themore » fluctuations to both mean flows.« less

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Works referenced in this record:

Role of the geodesic acoustic mode shearing feedback loop in transport bifurcations and turbulence spreading
journal, March 2010

  • Miki, K.; Diamond, P. H.
  • Physics of Plasmas, Vol. 17, Issue 3
  • DOI: 10.1063/1.3353037

The role of the electric field in confinement
journal, January 1996


How does drift wave turbulence convert parallel compression into perpendicular flows?
journal, August 2012


Intrinsic rotation and electric field shear
journal, April 2007

  • Gürcan, Ö. D.; Diamond, P. H.; Hahm, T. S.
  • Physics of Plasmas, Vol. 14, Issue 4
  • DOI: 10.1063/1.2717891

Nonlinear energy transfer during the transition to drift-interchange turbulence
journal, July 2011


Dynamics of intrinsic axial flows in unsheared, uniform magnetic fields
journal, May 2016

  • Li, J. C.; Diamond, P. H.; Xu, X. Q.
  • Physics of Plasmas, Vol. 23, Issue 5
  • DOI: 10.1063/1.4950830

Scale interactions and scaling laws in rotating flows at moderate Rossby numbers and large Reynolds numbers
journal, January 2009

  • Mininni, P. D.; Alexakis, A.; Pouquet, A.
  • Physics of Fluids, Vol. 21, Issue 1
  • DOI: 10.1063/1.3064122

TOKAM-3D: A 3D fluid code for transport and turbulence in the edge plasma of Tokamaks
journal, January 2010


Physical Mechanism behind Zonal-Flow Generation in Drift-Wave Turbulence
journal, October 2009


Eddy Motion in the Atmosphere
journal, January 1915

  • Taylor, G. I.
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 215, Issue 523-537
  • DOI: 10.1098/rsta.1915.0001

Upscale energy transfer in thick turbulent fluid layers
journal, February 2011

  • Xia, H.; Byrne, D.; Falkovich, G.
  • Nature Physics, Vol. 7, Issue 4
  • DOI: 10.1038/nphys1910

The new SOLPS-ITER code package
journal, August 2015


Spatial and spectral evolution of turbulence
journal, May 2007

  • Gürcan, Ö. D.; Diamond, P. H.; Hahm, T. S.
  • Physics of Plasmas, Vol. 14, Issue 5
  • DOI: 10.1063/1.2436848

Particle and energy confinement bifurcation in tokamaks
journal, April 1993

  • Hinton, F. L.; Staebler, G. M.
  • Physics of Fluids B: Plasma Physics, Vol. 5, Issue 4
  • DOI: 10.1063/1.860919

Plasma Edge Turbulence
journal, February 1983


Nonadiabatic electron response in the Hasegawa-Wakatani equations
journal, August 2013

  • Stoltzfus-Dueck, T.; Scott, B. D.; Krommes, J. A.
  • Physics of Plasmas, Vol. 20, Issue 8
  • DOI: 10.1063/1.4816807

Self-organization of electrostatic turbulence in a cylindrical plasma
journal, October 1987


Transport matrix for particles and momentum in collisional drift waves turbulence in linear plasma devices
journal, February 2016

  • Ashourvan, Arash; Diamond, P. H.; Gürcan, Ö. D.
  • Physics of Plasmas, Vol. 23, Issue 2
  • DOI: 10.1063/1.4942420

An overview of intrinsic torque and momentum transport bifurcations in toroidal plasmas
journal, September 2013


Energetics of the interaction between electromagnetic ExB turbulence and zonal flows
journal, January 2005


Direct Observation of the Resistive Wall Mode in a Tokamak and Its Interaction with Plasma Rotation
journal, May 1999


Density Peaking by Parallel Flow Shear Driven Instability
journal, January 2015

  • Kosuga, Yusuke; Itoh, Sanae-I.; Itoh, Kimitaka
  • Plasma and Fusion Research, Vol. 10, Issue 0
  • DOI: 10.1585/pfr.10.3401024

Drift waves and transport
journal, April 1999


Negative viscosity from negative compressibility and axial flow shear stiffness in a straight magnetic field
journal, March 2017

  • Li, J. C.; Diamond, P. H.
  • Physics of Plasmas, Vol. 24, Issue 3
  • DOI: 10.1063/1.4978956

Intrinsic rotation, hysteresis and back transition in reversed shear internal transport barriers
journal, June 2011


Spontaneous profile self-organization in a simple realization of drift-wave turbulence
journal, March 2016

  • Cui, L.; Ashourvan, A.; Thakur, S. C.
  • Physics of Plasmas, Vol. 23, Issue 5
  • DOI: 10.1063/1.4944819

Zonal flows in plasma—a review
journal, April 2005


Structure formation in parallel ion flow and density profiles by cross-ferroic turbulent transport in linear magnetized plasma
journal, October 2016

  • Kobayashi, T.; Inagaki, S.; Kosuga, Y.
  • Physics of Plasmas, Vol. 23, Issue 10
  • DOI: 10.1063/1.4965915

Radial transport of fluctuation energy in a two-field model of drift-wave turbulence
journal, May 2006

  • Gürcan, Ö. D.; Diamond, P. H.; Hahm, T. S.
  • Physics of Plasmas, Vol. 13, Issue 5
  • DOI: 10.1063/1.2180668

On the efficiency of intrinsic rotation generation in tokamaks
journal, October 2010

  • Kosuga, Y.; Diamond, P. H.; Gürcan, Ö. D.
  • Physics of Plasmas, Vol. 17, Issue 10
  • DOI: 10.1063/1.3496055

Modelling enhanced confinement in drift-wave turbulence
journal, June 2017

  • Hajjar, R. J.; Diamond, P. H.; Ashourvan, A.
  • Physics of Plasmas, Vol. 24, Issue 6
  • DOI: 10.1063/1.4985323

Increased understanding of the dynamics and transport in ITB plasmas from multi-machine comparisons
journal, August 2003


Influence of sheared poloidal rotation on edge turbulence
journal, January 1990

  • Biglari, H.; Diamond, P. H.; Terry, P. W.
  • Physics of Fluids B: Plasma Physics, Vol. 2, Issue 1
  • DOI: 10.1063/1.859529

Zonal flow generation in parallel flow shear driven turbulence
journal, March 2017

  • Kosuga, Y.; Itoh, S. -I.; Itoh, K.
  • Physics of Plasmas, Vol. 24, Issue 3
  • DOI: 10.1063/1.4978485

Suppression of turbulence and transport by sheared flow
journal, January 2000


Inverse Energy Cascade in Three-Dimensional Isotropic Turbulence
journal, April 2012


Self-Regulating Shear Flow Turbulence: A Paradigm for the L to H Transition
journal, April 1994


A fully implicit, time dependent 2-D fluid code for modeling tokamak edge plasmas
journal, December 1992


A Concept of Cross-Ferroic Plasma Turbulence
journal, February 2016

  • Inagaki, S.; Kobayashi, T.; Kosuga, Y.
  • Scientific Reports, Vol. 6, Issue 1
  • DOI: 10.1038/srep22189

Zonal Flows and Transient Dynamics of the L H Transition
journal, May 2003


    Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.