NONLINEAR EVOLUTION OF ALPHA-PARTICLE-DRIVEN ALFVEN TURBULENCE FROM AREDUCED MODEL

Authors
Citation
F. Wising et Fy. Gang, NONLINEAR EVOLUTION OF ALPHA-PARTICLE-DRIVEN ALFVEN TURBULENCE FROM AREDUCED MODEL, Physics of plasmas, 1(1), 1994, pp. 120-126
Citations number
18
Categorie Soggetti
Phsycs, Fluid & Plasmas
Journal title
ISSN journal
1070664X
Volume
1
Issue
1
Year of publication
1994
Pages
120 - 126
Database
ISI
SICI code
1070-664X(1994)1:1<120:NEOAAT>2.0.ZU;2-I
Abstract
The coupled nonlinear evolution of kinetic Alfven turbulence (KAW) and anomalous alpha-particle transport is analyzed using a reduced turbul ence model [Phys. Fluids B 4, 3152 (1992)]. Due to the nonlocal nature of the nonlinear interaction (bulk ion Compton scattering), the satur ated spectrum consists of two well separated peaks, one in the linearl y unstable and one in the stable regime. The two peaks represent the e nergy input from the alphas and energy dissipation to the electrons, r espectively, and are in balance at saturation. Without a particle sour ce, the turbulence-induced anomalous alpha transport leads to a flatte ning of the initial alpha density profile, on a time scale slow compar ed to the fluctuation time scale. In the presence of a particle source , a stationary alpha density profile is built up self-consistently as a result of the competition between the alpha-particle source and anom alous transport. The anomalous alpha diffusivity from the reduced mode l for KAW, using reactor size parameters, is found to be D(alpha)an ap proximately 1 m2/s.