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Title: Exploring the regime of validity of global gyrokinetic simulations with spherical tokamak plasmas

Journal Article · · Nuclear Fusion
ORCiD logo [1];  [1]; ORCiD logo [1];  [1];  [2];  [1];  [1];  [1];  [1];  [3];  [4];  [5]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  3. Univ. of Wisconsin, Madison, WI (United States)
  4. Univ. of California, Davis, CA (United States)
  5. Nova Photonics, Inc., Princeton, NJ (United States)

Plasma turbulence is considered one of the main mechanisms for driving anomalous thermal transport in magnetic confinement fusion devices. Based on first-principle model, gradient driven gyrokinetic simulations have often been used to explain turbulence-driven transport in present fusion devices, and in fact, many present predictive codes are based on the assumption that turbulence is gradient-driven. However, using the electrostatic global particle-in-cell gyrokinetic tokamak simulation (GTS) code (Wang et al 2010 Phys. Plasmas 17 072511), we will show that while global gradient-driven gyrokinetic simulations provide decent agreement in ion thermal transport with a set of NBI-heated NSTX (Ono et al 2000 Nucl. Fusion 40 557) H-mode plasmas, they are not able to explain the observed electron thermal transport variation in a set of RF-heated L-mode plasmas, where a factor of 2 decrease in electron heat flux is observed after the cessation of the RF heating. Thus, identifying the regime of validity of the gradient-driven assumption is essential for first-principle gyrokinetic simulation. This understanding will help us to more confidently predict the confinement performance of ITER and future magnetic confinement devices.

Research Organization:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Univ. of California, Davis, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Grant/Contract Number:
AC02-09CH11466; AC02-76CH03073; FG03-95ER54295; FG03-99ER54518; FG02-99ER54518
OSTI ID:
1616946
Alternate ID(s):
OSTI ID: 1777994
Journal Information:
Nuclear Fusion, Vol. 60, Issue 2; ISSN 0029-5515
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 7 works
Citation information provided by
Web of Science

References (47)

Measurements of the cross-phase angle between density and electron temperature fluctuations and comparison with gyrokinetic simulations journal May 2010
The E × B staircase of magnetised plasmas journal April 2017
Finding the Elusive E × B Staircase in Magnetized Plasmas journal February 2015
Identification of new turbulence contributions to plasma transport and confinement in spherical tokamak regime journal October 2015
Theory of the ubiquitous mode journal October 1977
Overview of the physics and engineering design of NSTX upgrade conference June 2011
On the validity of the local diffusive paradigm in turbulent plasma transport journal August 2010
Cross-Scale Interactions between Electron and Ion Scale Turbulence in a Tokamak Plasma journal June 2015
Advances in validating gyrokinetic turbulence models against L- and H-mode plasmas journal May 2011
Large scale dynamics in flux driven gyrokinetic turbulence journal April 2010
Plasma size and power scaling of ion temperature gradient driven turbulence journal February 2014
Nonlinear flow generation by electrostatic turbulence in tokamaks journal July 2010
Multi-scale gyrokinetic simulation of tokamak plasmas: enhanced heat loss due to cross-scale coupling of plasma turbulence journal December 2015
Electron Temperature Gradient Turbulence journal December 2000
High-Harmonic Fast-Wave heating in NSTX conference January 2001
Anomalous Transport Scaling in the DIII-D Tokamak Matched by Supercomputer Simulation journal July 2003
Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment journal November 2015
Comparison of initial value and eigenvalue codes for kinetic toroidal plasma instabilities journal August 1995
Comparison of gradient and flux driven gyro-kinetic turbulent transport journal May 2016
Ion temperature gradient turbulence simulations and plasma flux surface shape journal November 1999
Electromagnetic Transport from Microtearing Mode Turbulence journal April 2011
Nonlocal properties of gyrokinetic turbulence and the role of E×B flow shear journal July 2007
Gyrokinetic full-torus simulations of ohmic tokamak plasmas in circular limiter configuration journal June 2016
Microinstability theory in tokamaks journal August 1978
Collisionless electron temperature gradient instability journal January 1987
Finite-β simulation of microinstabilities journal February 2014
Stabilization of electron-scale turbulence by electron density gradient in national spherical torus experiment journal December 2015
Gyrokinetic simulations of turbulent transport journal March 2010
Experimental study of parametric dependence of electron-scale turbulence in a spherical tokamak journal May 2012
The first transport code simulations using the trapped gyro-Landau-fluid model journal May 2008
Tokamak edge turbulence: background theory and computation journal June 2007
Study of ion turbulent transport and profile formations using global gyrokinetic full- f Vlasov simulation journal May 2009
Microtearing Modes and Anomalous Transport in Tokamaks journal April 1980
Tokamak Heat Transport Due to Tearing Modes journal July 1976
Kinetic-ballooning-mode theory in general geometry journal November 1980
Confinement and local transport in the National Spherical Torus Experiment (NSTX) journal June 2007
Carbon ion plume emission produced by charge exchange with neutral beams on National Spherical Torus Experiment journal October 2006
Exploration of spherical torus physics in the NSTX device journal March 2000
Studies of turbulence and transport in Alcator C-Mod H-mode plasmas with phase contrast imaging and comparisons with GYRO journal January 2009
Validation in fusion research: Towards guidelines and best practices journal June 2008
Full f gyrokinetic method for particle simulation of tokamak transport journal May 2008
Bootstrap current and neoclassical transport in tokamaks of arbitrary collisionality and aspect ratio journal September 1997
A collective scattering system for measuring electron gyroscale fluctuations on the National Spherical Torus Experiment journal December 2008
Ion temperature gradient turbulence close to the finite heat flux threshold journal October 2017
Gradient-driven flux-tube simulations of ion temperature gradient turbulence close to the non-linear threshold journal August 2016
Trapped particles in toroidal magnetic systems journal January 1971
Validation in Fusion Research: Towards Guidelines and Best Practices text January 2008