Linear gyrokinetic simulation of high-n toroidal Alfven eigenmodes in a burning plasma

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3490213· OSTI ID:21421260

Yang, Chen; Parker, Scott E ^[1]; Lang, J; Fu, G -Y ^[2]

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1. University of Colorado at Boulder, Boulder, Colorado 80309 (United States)
2. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543-0451 (United States)

A hybrid gyrokinetic ions/massless fluid electron model is used to study the stability of high-n toroidal Alfven eigenmodes (TAEs) in ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)]. The hybrid model has been implemented in the particle-in-cell turbulence simulation code GEM [Y. Chen and S. E. Parker, J. Comput. Phys. 220, 839 (2007)]. The adequacy of the hybrid model for simulating TAEs has been previously demonstrated [J. Lang et al., Phys. Plasmas 16, 102101 (2009)] by comparing the simulated TAE mode frequency and structure with an eigenmode analysis, and the thermal ion kinetic damping effect with analytic theory. By using a global particle-in-cell code the effects of large orbit width and nonlocal mode structures can be accurately included. Damping rate due to numerical filtering is carefully monitored, and convergence with respect to particle number, grid resolution, etc., is thoroughly tested. The simulations show that the most unstable modes in ITER lie in the rage of 10<n<20. Thermal ion pressure effect and alpha particle nonperturbative effect are important in determining the mode radial location and stability threshold. The thermal ion Landau damping rate and radiative damping rate from the simulations are compared with analytical estimates. The thermal ion Landau damping is the dominant damping mechanism. Plasma elongation has a strong stabilizing effect on the alpha driven TAEs. The central alpha particle pressure threshold for the most unstable n=15 mode is about {beta}{sub {alpha}(0)}=0.7% for the fully shaped ITER equilibrium.

• OSTI ID: 21421260
• Journal Information: Physics of Plasmas, Vol. 17, Issue 10; Other Information: DOI: 10.1063/1.3490213; (c) 2010 American Institute of Physics; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
ALPHA PARTICLES
IONS
ITER TOKAMAK
LANDAU DAMPING
PLASMA PRESSURE
PLASMA SIMULATION
PRESSURE DEPENDENCE
CHARGED PARTICLES
CLOSED PLASMA DEVICES
DAMPING
HYDROMAGNETIC WAVES
IONIZING RADIATIONS
RADIATIONS
SIMULATION
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TOKAMAK DEVICES
TOKAMAK TYPE REACTORS