Analytic slowing-down distributions as modified by turbulent transport
Journal article, 2018

The effect of electrostatic microturbulence on fast particles rapidly decreases at high energy, but can be significant at moderate energy. Previous studies found that, in addition to changes in the energetic particle density, this results in non-trivial changes to the equilibrium velocity distribution. These effects have implications for plasma heating and the stability of Alfven eigenmodes, but make multiscale simulations much more difficult without further approximations. Here, several related analytic model distribution functions are derived from first principles. A single dimensionless parameter characterizes the relative strength of turbulence relative to collisions, and this parameter appears as an exponent in the model distribution functions. Even the most simple of these models reproduces key features of the numerical phase-space transport solution and provides a useful a priori heuristic for determining how strong the effect of turbulence is on the redistribution of energetic particles in toroidal plasmas.

plasma heating

plasma confinement

fusion plasma

Author

George Wilkie

Chalmers, Physics, Subatomic and Plasma Physics

Journal of Plasma Physics

0022-3778 (ISSN) 1469-7807 (eISSN)

Vol. 84 6 745840601

Subject Categories

Applied Mechanics

Other Physics Topics

Fusion, Plasma and Space Physics

DOI

10.1017/S0022377818001058

More information

Latest update

10/3/2019