title: Radial structure of Alfvén eigenmodes in the DIII-D tokamak through electron-cyclotron-emission measurements.
abstract: 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.
authors.affiliation: Oak Ridge Institute for Science Education, P.O. Box 117, Oak Ridge, TN 37831-0117, USA. vanzeeland@fusion.gat.com
authors.forename: M A
authors.initials: MA
authors.lastname: Van Zeeland
authors.forename: G J
authors.initials: GJ
authors.lastname: Kramer
authors.forename: M E
authors.initials: ME
authors.lastname: Austin
authors.forename: R L
authors.initials: RL
authors.lastname: Boivin
authors.forename: W W
authors.initials: WW
authors.lastname: Heidbrink
authors.forename: M A
authors.initials: MA
authors.lastname: Makowski
authors.forename: G R
authors.initials: GR
authors.lastname: McKee
authors.forename: R
authors.initials: R
authors.lastname: Nazikian
authors.forename: W M
authors.initials: WM
authors.lastname: Solomon
authors.forename: G
authors.initials: G
authors.lastname: Wang