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Nonlinear MHD simulations of Quiescent H-mode plasmas in DIII-D

Journal Article · · Nuclear Fusion
 [1];  [2];  [2];  [3];  [4];  [3];  [5];  [6]
  1. ITER Organization, St. Paul Lez Durance (France); General Atomics
  2. ITER Organization, St. Paul Lez Durance (France)
  3. General Atomics, San Diego, CA (United States)
  4. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  5. Max Planck Inst. for Plasma Physics, Garching (Germany)
  6. Univ. of California, Los Angeles, CA (United States)
In the Quiescent H-mode (QH-mode) regime, the edge harmonic oscillation (EHO), thought to be a saturated kink-peeling mode (KPM) driven unstable by current and rotation, is found in experiment to provide sufficient stationary edge particle transport to avoid the periodic expulsion of particles and energy by edge localized modes (ELMs). In this article, both linear and nonlinear MHD modelling of QH-mode plasmas from the DIII-D tokamak have been investigated to understand the mechanism leading to the appearance of the EHO in QH-mode plasmas. For the first time nonlinear MHD simulations with low-n modes both with ideal wall and resistive wall boundary conditions have been carried out with 3-D non-linear MHD code JOREK. The results show, in agreement with the original conjectures, that in the nonlinear phase, kink peeling modes are the main unstable modes in QH-mode plasmas of DIIID and that the kink-peeling modes saturate non-linearly leading to a 3-D stationary state. The characteristics of the kink-peeling modes, in terms of mode structure and associated decrease of the edge plasma density associated with them, are in good agreement with experimental measurements of the EHO in DIII-D. Finally, the effect of plasma resistivity, the role of plasma parallel rotation as well as the effect of the conductivity of the vacuum vessel wall on the destabilization and saturation of kink-peeling modes have been evaluated for experimental QH-mode plasma conditions in DIII-D.
Research Organization:
General Atomics, San Diego, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
Grant/Contract Number:
AC02-09CH11466; FC02-04ER54698
OSTI ID:
1375950
Alternate ID(s):
OSTI ID: 1238897
Journal Information:
Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 11 Vol. 55; ISSN 0029-5515
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English

References (29)

PaStiX: a high-performance parallel direct solver for sparse symmetric positive definite systems journal February 2002
Bézier surfaces and finite elements for MHD simulations journal August 2008
MHD stability of the ITER pedestal and SOL plasma and its influence on the heat flux width journal August 2015
Quiescent double barrier high-confinement mode plasmas in the DIII-D tokamak journal May 2001
Modeling of diamagnetic stabilization of ideal magnetohydrodynamic instabilities associated with the transport barrier journal October 2001
Edge localized modes and the pedestal: A model based on coupled peeling–ballooning modes journal May 2002
Magnetohydrodynamics modelling of H-mode plasma response to external resonant magnetic perturbations journal September 2007
The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmasa) journal May 2015
The ion velocity (Bohm–Chodura) boundary condition at the entrance to the magnetic presheath in the presence of diamagnetic and E×B drifts in the scrape‐off layer journal March 1995
Equilibrium analysis of current profiles in tokamaks journal June 1990
Studies of the ‘Quiescent H-mode’ regime in ASDEX Upgrade and JET journal July 2005
Energy loss for grassy ELMs and effects of plasma rotation on the ELM characteristics in JT-60U journal July 2005
Chapter 4: Power and particle control journal June 2007
MHD stability in X-point geometry: simulation of ELMs journal June 2007
Stability and dynamics of the edge pedestal in the low collisionality regime: physics mechanisms for steady-state ELM-free operation journal August 2007
Quasi-linear MHD modelling of H-mode plasma response to resonant magnetic perturbations journal February 2010
Advances towards QH-mode viability for ELM-stable operation in ITER journal July 2011
Quiescent H-mode operation using torque from non-axisymmetric, non-resonant magnetic fields journal June 2013
3D vacuum magnetic field modelling of the ITER ELM control coil during standard operating scenarios journal August 2013
Investigations on the edge kinetic data in regimes with type-I and mitigated ELMs at ASDEX Upgrade journal August 2014
ITER transient consequences for material damage: modelling versus experiments journal March 2007
Characteristics of type I ELM energy and particle losses in existing devices and their extrapolation to ITER journal August 2003
Magnetic triggering of ELMs in TCV journal August 2003
Impact of toroidal rotation on ELM behaviour in the H-mode on JT-60U journal April 2004
ELMs: MHD instabilities at the transport barrier journal November 2005
Active control of type-I edge localized modes on JET journal November 2007
Coupling JOREK and STARWALL Codes for Non-linear Resistive-wall Simulations journal December 2012
Access to a New Plasma Edge State with High Density and Pressures using the Quiescent H Mode journal September 2014
Resistive Reduced MHD Modeling of Multi-Edge-Localized-Mode Cycles in Tokamak X -Point Plasmas journal January 2015

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