title: Observation of reduced electron-temperature fluctuations in the core of H-mode plasmas.
abstract: Core electron-temperature fluctuations [0.5%< or =T[over ]_(e)/T_(e)< or =2%, k_(theta)rho_(s)< or =0.3 in neutral-beam-heated low confinement-mode (L-mode) plasmas] are observed to decrease by at least a factor of 4 in standard and quiescent high-confinement-mode (H-mode and QH-mode) regimes in the DIII-D tokamak (r/a=0.7). These fluctuations are attributed to ion temperature gradient (ITG) modes stabilized by rotational shear at the H-mode transition. The simultaneous reduction in electron heat diffusivity (chi_(e)(QH)/chi_(e)(L)<0.25) suggests that T[over ]_(e) fluctuations can contribute significantly to L-mode electron heat transport.
authors.affiliation: Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, CA 90024-2704, USA.
authors.forename: L
authors.initials: L
authors.lastname: Schmitz
authors.forename: A E
authors.initials: AE
authors.lastname: White
authors.forename: T A
authors.initials: TA
authors.lastname: Carter
authors.forename: W A
authors.initials: WA
authors.lastname: Peebles
authors.forename: T L
authors.initials: TL
authors.lastname: Rhodes
authors.forename: K H
authors.initials: KH
authors.lastname: Burrell
authors.forename: W
authors.initials: W
authors.lastname: Solomon
authors.forename: G M
authors.initials: GM
authors.lastname: Staebler