title: Measurement of turbulent electron temperature fluctuations on the ASDEX Upgrade tokamak using correlated electron cyclotron emission.
abstract: Turbulent temperature fluctuations are measured on the ASDEX Upgrade tokamak using pairs of closely spaced, narrow-band heterodyne radiometer channels and a standard correlation technique. The pre-detection spacing and bandwidth of the radiometer channel pairs is chosen such that they are physically separated less than a turbulent correlation length, but do not overlap. The radiometer has 4 fixed filter frequency channels and two tunable filter channels for added flexibility in the measurement position. Relative temperature fluctuation amplitudes are observed in a helium plasma to be δT/T = (0.76 ± 0.02)%, (0.67 ± 0.02)%, and (0.59 ± 0.03)% at normalised toroidal flux radius of ρtor= 0.82, 0.75, and 0.68, respectively.
authors.affiliation: Max Planck Institute for Plasma Physics, 85748 Garching, Germany.
authors.forename: S J
authors.initials: SJ
authors.lastname: Freethy
authors.affiliation: Max Planck Institute for Plasma Physics, 85748 Garching, Germany.
authors.forename: G D
authors.initials: GD
authors.lastname: Conway
authors.affiliation: FOM Institute DIFFER, 5612 AJ Eindhoven, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Classen
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Creely
authors.affiliation: Max Planck Institute for Plasma Physics, 85748 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Happel
authors.affiliation: Max Planck Institute for Plasma Physics, 85748 Garching, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Köhn
authors.affiliation: FOM Institute DIFFER, 5612 AJ Eindhoven, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Vanovac
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: White