Hybrid magnetohydrodynamic-gyrokinetic simulation of toroidal Alfven modes
- Associazione Euratom-ENEA sulla Fusione, C.R.E. Frascati, C.P. 65-00044-Frascati, Rome (Italy)
Resonant energetic particles play a major role in determining the stability of toroidal Alfven eigenmodes (TAE`s) by yielding the well-known driving mechanism for the instability and by producing an effective dissipation, which removes the singular character of local oscillations of the shear-Alfven continuum and gives discrete kinetic Alfven waves (KAW`s). Toroidal coupling of two counterpropagating KAW`s generates the kinetic analog of the TAE, the KTAE (kinetic TAE). The nonperturbative character of this phenomenon and of the coupling between TAE and KAW`s, and the relevance of finite drift-orbit effects limit the effectiveness of the analytical approach to asymptotic regimes, which are difficult to compare with realistic situations. A three-dimensional hybrid fluid-particle initial-value code for the numerical simulation of the linear and nonlinear evolution of toroidal modes of the Alfven branch has been developed. It is shown that for typical parameters the KTAE is, indeed, more unstable than the TAE. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
- OSTI ID:
- 168218
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 2; ISSN 1070-664X; ISSN PHPAEN
- Country of Publication:
- United States
- Language:
- English
Similar Records
Kinetic theory of toroidicity-induced Alfven eigenmodes
Multiple-gap theory of toroidal Alfven waves with kinetic effects