Radial structure of Alfvén eigenmodes in the DIII-D tokamak through electron-cyclotron-emission measurements.
The spatial structure of toroidal Alfvén eigenmodes and reversed shear Alfvén eigenmodes in DIII-D is obtained from electron-cyclotron-emission measurements. Peak measured temperature perturbations are of similar magnitude for both toroidal Alfvén eigenmodes and reversed shear Alfvén eigenmodes and found to be deltaT(e)/T(e) approximately equal to 0.5%. Simultaneous measurements of density fluctuations using beam-emission spectroscopy indicate deltan(e)/n(e) approximately equal to 0.25%. Predictions of the measured temperature and density perturbation profiles as well as deltaT(e)/deltan(e) from the ideal magnetohydrodynamic code NOVA are in close agreement with experiment.
Van Zeeland
M A
MA
Oak Ridge Institute for Science Education, P.O. Box 117, Oak Ridge, TN 37831-0117, USA. vanzeeland@fusion.gat.com
Kramer
G J
GJ
Austin
M E
ME
Boivin
R L
RL
Heidbrink
W W
WW
Makowski
M A
MA
McKee
G R
GR
Nazikian
R
R
Solomon
W M
WM
Wang
G
G