Speaker
Dr
Jane Pratt
(University of Exeter Astrophysics)
Description
When a fusion plasma is above a critical value of beta,
neoclassical tearing modes
are destabilized. The resulting magnetic islands can grow to
large size, allowing
fast escape of the plasma from the fusion machine. The
primary tactic for preventing
tearing modes and reducing the size of magnetic islands in
fusion machines is to
apply current inside the magnetic islands. In ITER, this will
be done using electron
cyclotron current drive. To study the stabilization processes
inside an island in
detail, we have extended the JOREK code[1], a three-
dimensional compressible
non-linear MHD code that simulates a realistic tokamak
geometry, to include two
coupled equations for the applied current. We describe the
evolution of the applied
current, and analyze how it spreads along surfaces of
constant magnetic flux inside
the magnetic islands.
[1]Huysmans, G. T. A., and O. Czarny. ``MHD stability in X-
point geometry: simulation
of ELMs.'' Nuclear fusion 47.7 (2007): 659.
Primary author
Dr
Jane Pratt
(University of Exeter Astrophysics)
Co-author
Dr
Egbert Westerhof
(DIFFER (Dutch Institute for Fundamental Energy Research))
