Impact of velocity space distribution on hybrid kinetic-magnetohydrodynamic simulation of the (1,1) mode
- Plasma Science and Innovation Center, University of Washington, Seattle, Washington 91895-2250 (United States)
Numeric studies of the impact of the velocity space distribution on the stabilization of (1,1) internal kink mode and excitation of the fishbone mode are performed with a hybrid kinetic-magnetohydrodynamic model. These simulations demonstrate an extension of the physics capabilities of NIMROD[C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004)], a three-dimensional extended magnetohydrodynamic (MHD) code, to include the kinetic effects of an energetic minority ion species. Kinetic effects are captured by a modification of the usual MHD momentum equation to include a pressure tensor calculated from the {delta}f particle-in-cell method [S. E. Parker and W. W. Lee, Phys. Fluids B 5, 77 (1993)]. The particles are advanced in the self-consistent NIMROD fields. We outline the implementation and present simulation results of energetic minority ion stabilization of the (1,1) internal kink mode and excitation of the fishbone mode. A benchmark of the linear growth rate and real frequency is shown to agree well with another code. The impact of the details of the velocity space distribution is examined; particularly extending the velocity space cutoff of the simulation particles. Modestly increasing the cutoff strongly impacts the (1,1) mode. Numeric experiments are performed to study the impact of passing versus trapped particles. Observations of these numeric experiments suggest that assumptions of energetic particle effects should be re-examined.
- OSTI ID:
- 21268963
- Journal Information:
- Physics of Plasmas, Vol. 15, Issue 7; Other Information: DOI: 10.1063/1.2949704; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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