Integrated Simulations of Energetic Particle-driven

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Integrated Simulations of Energetic
Particle-driven Modes in Burning Plasmas
Guo-Yong Fu Princeton Plasma Physics Laboratory
US-Japan Workshop on Integrated Simulations,
ORNL, Jan. 30th, 2007
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Outline

• Hybrid model of M3D
• Highlights of M3D Hybrid Simulations
• Issues for integrated simulation of energetic
  particle-driven modes in burning plasmas

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M3D XMHD Model
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CGL pressure and gyrokinetic equations
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Highlights of Recent M3D Hybrid Simulations

• n1 mode in ITER
• Fishbone nonlinear evolution in tokamak
• Beam-driven Alfven modes in NSTX
• Ref G.Y. Fu et al., IAEA Fusion Energy
  Conference, 2004.
• H.R. Strauss et al, Nucl. Fusion 44, 1008
  (2004).
• G.Y. Fu et al., Phys. Plasma 13, 052517,
  2006.

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n1 mode in ITER

• Importance of shaping effects on alpha particle
  stabilization of internal kink
• fishbone stability is marginal
• Ion kinetic effects are strongly stabilizing.

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Alpha Particle Stabilization of Internal Kink
Mode for ITERInternal Kink Mode Structure
ba0.0
ba1.0
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Plasma shaping reduces alpha particle
stabilization significantly
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Thermal ion kinetic effectsreduce MHD growth
rateby half (Kruskal-Oberman)
P
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Beam-driven Alfven modes in NSTX

• TAE frequency chirping
• Multi-mode simulations show significant effects
  from mode-mode coupling

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Beam-driven modes in NSTX frequency chirping
.
t0.0
t336
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Multi-mode simulations of beam-driven Alfven
modes show strong interaction between different
toroidal modes
n1 n2 n3
n1 n2 n3
Red multi-mode Blue single mode
time
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Simulation of fishbone shows distribution
fattening and strong frequency chirping
distribution
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Initial simulations of Alfven eigenmodes in
reversed shear DIIID plasmas
Velocity stream function
Pressure perturbation
Total pressure
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Future Direction for Energetic Particle Physics

• Linear Stability basic mechanisms well
  understood, but lack of a comprehensive code
  which treats dampings and energetic particle
  drive non-perturbatively
• Nonlinear Physics single mode saturation well
  understood, but lack of study for multi-mode
  dynamics
• Effects of energetic particles on thermal
  plasmas needs a lot of work (integrated
  simulations).

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Integration of Energetic Particle Physics
Current drive rotation
Alfven instability
NBI RF Alphas
Energetic particles
Plasma confinement
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Experimental motivation for integrated simulations
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Issues for integrated simulations

• Integration of physics kinetic MHD
• Integration of different modes
• Integration of different time scale

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Integration of physics kinetic MHD

• Alpha particle stabilization of internal kink
  mode
• Energetic particle destabilization
• FLR effects
• Ion and electron Landau damping

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Integration of different modes

• TAE
• Fishbone/EPM
• Tearing modes
• KBM

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Integration of different time scales

• Shear Alfven time
• Linear growth time of Alfven eigenmodes
• Energetic particle slowing down time and velocity
  diffusion time
• Plasma confinement time
• Equilibrium evolution time (q profile).