Τίτλος:
Diffraction of radio frequency waves by spatially modulated interfaces
in the plasma edge in tokamaks
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
The use of radio frequency (RF) waves in fusion plasmas for heating, for
non-inductive current generation, for profile control and for
diagnostics has been well established. The RF waves, excited by antenna
structures placed near the wall of a fusion device, have to propagate
through density fluctuations at the plasma edge. These fluctuations can
modify the properties of the RF waves that propagate towards the core of
the plasma. A full-wave electromagnetic computational code ScaRF based
on the finite difference frequency domain (FDFD) method has been
developed to study the effect of density turbulence on RF waves. The
anisotropic plasma permittivity used in the scattering studies is that
for a magnetized, cold plasma. The code is used to study the propagation
of an RF plane wave through a modulated, spatially periodic density
interface. Such an interface could arise in the edge region due to
magnetohydrodynamic instability or drift waves. The frequency of the
plane wave is taken to be in the range of the electron cyclotron
frequency. The scattering analysis is applicable to ITER-like plasmas,
as well as to plasmas in medium sized tokamaks such as TCV, ASDEX-U and
DIII-D. The effect of different density contrasts across the interface
and of different spatial modulations are discussed. While ScaRF is used
to study a periodic density fluctuation, the code is general enough to
include different varieties of density fluctuations in the edge region -
such as blobs and filaments, and spatially random fluctuations.
Συγγραφείς:
Papadopoulos, A. D.
Glytsis, E. N.
Ram, A. K.
Valvis, I, S.
and Papagiannis, P.
Hizanidis, K.
Zisis, A.
Περιοδικό:
Journal of Plasma Physics
Εκδότης:
Cambridge University Press
Λέξεις-κλειδιά:
fusion plasma; plasma simulation; plasma waves
DOI:
10.1017/S0022377819000308
