Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Effect of the tangential NBI current drive on the stability of pressure and energetic particle driven MHD modes in LHD plasma

Journal Article · · Nuclear Fusion
 [1];  [2];  [1];  [1];  [3];  [4];  [5];  [1]
  1. National Institute for Fusion Science (NIFS), Toki (Japan)
  2. Ecole Polytechnique Federale Lausanne (Switzerland)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Univ. Carlos III de Madrid (Spain)
  5. Research Centre for Energy, Environment and Technology (CIEMAT), Madrid (Spain)
The aim of the present study is to analyze the stability of the pressure gradient driven modes (PM) and Alfvén eigenmodes (AE) in the large helical device (LHD) plasma if the rotational transform profile is modified by the current drive of the tangential neutral beam injectors (NBI). This study forms a basic search for optimized operation scenarios with reduced mode activity. Here, the analysis is performed using the code FAR3d which solves the reduced MHD equations describing the linear evolution of the poloidal flux and the toroidal component of the vorticity in a full 3D system, coupled with equations for density and parallel velocity moments of the energetic particle (EP) species, including the effect of the acoustic modes. The Landau damping and resonant destabilization effects are added via the closure relation. On-axis and off-axis NBI current drive modifies the rotational transform which becomes strongly distorted as the intensity of the neutral beam current drive (NBCD) increases, leading to wider continuum gaps and modifying the magnetic shear. The simulations with on-axis NBI injection show that a counter (ctr-) NBCD in inward shifted and default configurations leads to a lower growth rate of the PM, although strong n = 1 and 2 AEs can be destabilized. For the outward shifted configurations, a co-NBCD improves the AEs stability but the PM are further destabilized if the co-NBCD intensity is 30 kA T–1. If the NBI injection is off-axis, the plasma stability is not significantly improved due to the further destabilization of the AE and energetic particle modes (EPM) in the middle and outer plasma region.
Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE; National Institute of Fusion Science (NIFS)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1817581
Alternate ID(s):
OSTI ID: 23013520
Journal Information:
Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 2 Vol. 60; ISSN 0029-5515
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English

References (89)

Numerical calculations using the full MHD equations in toroidal geometry journal March 1986
Compressible linear and nonlinear resistive MHD calculations in toroidal geometry journal February 1990
An Eulerian gyrokinetic-Maxwell solver journal April 2003
A δf particle method for gyrokinetic simulations with kinetic electrons and electromagnetic perturbations journal August 2003
Three-dimensional anisotropic pressure free boundary equilibria journal September 2009
Heating and current drive by electron cyclotron waves journal May 2004
Nonlocal energetic particle mode in a JT-60U plasma journal January 2005
Nonlinear low noise particle-in-cell simulations of electron temperature gradient driven turbulence journal January 2007
Gyrokinetic particle simulations of reversed shear Alfvén eigenmode excited by antenna and fast ions journal November 2010
Effect of pressure-driven MHD instabilities on confinement in reactor-relevant high-beta helical plasmas journal May 2011
Internal disruptions and sawtooth like activity in Large Helical Device journal August 2012
The internal disruption as hard Magnetohydrodynamic limit of 1/2 sawtooth like activity in large helical device journal August 2012
Hard magnetohydrodynamic limit in 1/3 sawtooth like activity in LHD journal March 2014
Magnetic turbulence and pressure gradient feedback effect of the 1/2 mode soft-hard magnetohydrodynamic limit in large helical device journal September 2014
Pullback transformation in gyrokinetic electromagnetic simulations journal September 2014
Progress toward steady-state tokamak operation exploiting the high bootstrap current fraction regime journal June 2016
Effect of fast electrons on the stability of resistive interchange modes in the TJ-II stellarator journal June 2016
Low‐ n stability calculations for three‐dimensional stellarator configurations journal September 1990
The bootstrap current in stellarators journal October 1990
Alpha‐Alfvén local dispersion relation and solutions journal December 1992
Linearized gyrofluid model of the alpha‐destabilized toroidal Alfvén eigenmode with continuum damping effects journal October 1992
Establishment of magnetic coordinates for a given magnetic field journal January 1982
Steepest-descent moment method for three-dimensional magnetohydrodynamic equilibria journal January 1983
Stability of bootstrap current‐driven magnetic islands in stellarators journal September 1994
High‐mode‐number ballooning modes in a heliotron/torsatron system. II. Stability journal December 1996
High‐mode‐number ballooning modes in a heliotron/torsatron system. I. Local magnetic shear journal December 1996
On the stabilization of neoclassical magnetohydrodynamic tearing modes using localized current drive or heating journal August 1997
An investigation of beam driven Alfvén instabilities in the DIII-D tokamak journal September 1991
Loss of energetic beam ions during TAE instabilities journal May 1993
Bootstrap current in a tokamak journal September 1994
Characteristics of Alfvén eigenmodes, burst modes and chirping modes in the Alfvén frequency range driven by negative ion based neutral beam injection in JT-60U journal November 1999
Stability of alpha particle driven Alfvén eigenmodes in high performance JET DT plasmas journal March 1999
Stability of alpha particle driven Alfvén eigenmodes in high performance JET DT plasmas journal May 1999
Heating and non-inductive current drive by negative ion based NBI in JT-60U journal March 2000
Effects of non-vanishing toroidal current densities on stability in the Wendelstein 7-AS stellarator journal August 2000
Recent progress of Alfvén eigenmode experiments using N-NB in JT-60U tokamak journal August 2002
MHD instabilities and their effects on plasma confinement in Large Helical Device plasmas journal January 2004
Heating and current drive by electron cyclotron waves in JT-60U journal May 2004
Effects of global MHD instability on operational high beta-regime in LHD journal October 2005
100% noninductive operation at high beta using off-axis ECCD in DIII-D journal October 2005
Stabilization of neoclassical tearing mode by ECCD and its evolution simulation on JT-60U tokamak journal November 2005
Experimental studies of energetic-ion-driven MHD instabilities in Large Helical Device plasmas journal April 2005
Overview of JT-60U results for the development of a steady-state advanced tokamak scenario journal September 2007
Stabilization and prevention of the 2/1 neoclassical tearing mode for improved performance in DIII-D journal April 2007
Control of non-inductive current in Heliotron J journal August 2007
Neoclassical tearing mode control using electron cyclotron current drive and magnetic island evolution in JT-60U journal April 2009
Non-inductive current drive and transport in high β N plasmas in JET journal April 2009
Off-axis neutral beam current drive for advanced scenario development in DIII-D journal May 2009
A lower hybrid current drive system for ITER journal May 2009
Integrated modelling of steady-state scenarios and heating and current drive mixes for ITER journal August 2011
Simulation of Alfvén frequency cascade modes in reversed shear-discharges using a Landau-closure model journal April 2013
Mitigation of NBI-driven Alfvén eigenmodes by electron cyclotron heating in the TJ-II stellarator journal July 2013
Electron cyclotron heating can drastically alter reversed shear Alfvén eigenmode activity in DIII-D through finite pressure effects journal July 2016
Electron cyclotron resonance heating and current drive in toroidal fusion plasmas journal December 1994
Kinetic theory of low-frequency Alfvén modes in tokamaks journal November 1996
Plasma characteristics of long-pulse discharges heated by neutral beam injection in the Large Helical Device journal January 2000
RF current drive by electron cyclotron waves in the presence of magnetic islands journal May 2000
Influence of magnetic topology on transport and stability in stellarators journal November 2005
Observation of localized oscillations at m / n = 2/1 rational surface during counter neutral beam injection in the Large Helical Device journal March 2006
MHD study of the reactor-relevant high-beta regime in the Large Helical Device journal November 2008
A reduced fast ion transport model for the tokamak transport code TRANSP journal April 2014
Electromagnetic stabilization of tokamak microturbulence in a high- β regime journal November 2014
Influence of magnetic well on electromagnetic turbulence in the TJ-II stellarator journal July 2016
The Influence of Neutral Beam Injection on the Heating and Current Drive with Electron Cyclotron Wave on EAST journal October 2016
High Power Neutral Beam Injection in LHD journal January 2006
The effects of electron cyclotron heating and current drive on toroidal Alfvén eigenmodes in tokamak plasmas journal November 2017
3D effects on transport and plasma control in the TJ-II stellarator journal August 2017
Suppression of fast-ion-driven MHD instabilities by ECH/ECCD on Heliotron J journal November 2017
Tokamak Magnetohydrodynamic Equilibrium States with Axisymmetric Boundary and a 3D Helical Core journal July 2010
Magnetic Topology Changes Induced by Lower Hybrid Waves and their Profound Effect on Edge-Localized Modes in the EAST Tokamak journal June 2013
Resistive Interchange Modes Destabilized by Helically Trapped Energetic Ions in a Helical Plasma journal April 2015
Suppression of Trapped Energetic Ions Driven Resistive Interchange Modes with Electron Cyclotron Heating in a Helical Plasma journal March 2017
Fluid moment models for Landau damping with application to the ion-temperature-gradient instability journal June 1990
Steady-State Fully Noninductive Current Driven by Electron Cyclotron Waves in a Magnetically Confined Plasma journal April 2000
Turbulent Transport Reduction by Zonal Flows: Massively Parallel Simulations journal September 1998
Progress on Electron Cyclotron Heating and Electron Cyclotron Current Drive Experiments in LHD journal October 2006
ECCD Experiments in the TJ-II Stellarator journal January 2008
Study of MHD Stability in LHD journal August 2010
High Performance of Neutral Beam Injectors for Extension of LHD Operational Regime journal August 2010
Effects of Resonant Magnetic Fluctuations on Plasma Confinement in Current Carrying high-β Plasmas of LHD journal January 2006
High Frequency Alfvén Eigen Modes Observed in LHD journal January 2006
ECCD Experiments in Heliotron J, TJ-II, CHS, and LHD journal January 2008
Ion Heating Experiments Using Perpendicular Neutral Beam Injection in the Large Helical Device journal January 2008
First Demonstration of Rotational Transform Control by Electron Cyclotron Current Drive in Large Helical Device journal January 2008
Monte-Carlo Study Based on Real Coordinates for Perpendicularly Injected High-Energy Ions in the LHD High-Beta Plasma journal January 2010
Monte Carlo Study Based on a Real Coordinate System for Tangentially Injected High-Energy Particles in the Large Helical Device journal January 2010
Ballooning Modes Instabilities in Outward LHD Configurations journal January 2011
ECCD Experiment Using an Upgraded ECH System on LHD journal January 2012
Pullback transformation in gyrokinetic electromagnetic simulations text January 2014

Similar Records

MHD stability trends and improved performance of LHD inward-shifted configurations: The role of the neutral beam current drive and thermal plasma density
Journal Article · Mon Aug 05 00:00:00 EDT 2024 · Physics of Plasmas · OSTI ID:2567707

Modeling of the ECCD injection effect on the Heliotron J and LHD plasma stability
Journal Article · Tue Sep 22 00:00:00 EDT 2020 · Nuclear Fusion · OSTI ID:1772609