Electromagnetic and kinetic electron physics effects on zonal flows and
toroidal momentum transport.
Zonal flows, analogous to the structured flows on the surface of Jupiter, play a
key role in Tokamak transport, and can substantially enhance the confinement
levels in certain situations. Toroidal flow structures also play a similar key role
in confinement as well as in suppressing large scale instabilities which can lead
to explosive release of energy.
These dynamics have been investigated in depth, but, until recently, under the
assumption that the electrons in the plasma are playing a limited supporting role
and simply responding adiabatically to the complex ion motion. State-of-the-art
supercomputing and advanced numerical algorithms as found in the
ORB5/NEMORB code now allow the full problem to be attacked; this project
aims to investigate how realistic electron physics and electromagnetic effects
modify the turbulent dynamics and plasma flows. Sufficiently strong
electromagnetic turbulence is known to allow the electrons to rapidly diffuse
across flux surfaces, and this has significant implications for zonal flow
evolution; the project will explore the impact of this physics on toroidal
momentum transport.
This project is partly funded via the EURATOM doctoral program, managed in
the UK via CCFE Culham.
Supervisor: Ben McMillan