Return To: Session EX6 - Transport 2
Prev Page: (EX6/4) Characteristics of Internal Transport Barrier in JT-60U
Next Page: (EX6/6) Observation of Bifurcation Property of Radial Electric

(EX6/5) Relating Nondimensional Scaling of Microturbulence to Global Confinement and Transport

G. R. McKee¹⁾, C. C. Petty²⁾, R. E. Waltz²⁾, C. Fenzi¹⁾, R. J. Fonck¹⁾, K. H. Burrell²⁾, D. R. Baker²⁾, E. J. Doyle³⁾, X. Garbet⁴⁾, J. E. Kinsey⁵⁾, T. C. Luce²⁾, R. A. Moyer⁶⁾, C. L. Rettig³⁾, T. L. Rhodes³⁾, D. R. Ross⁷⁾, G. M. Staebler²⁾, R. D. Sydora⁸⁾, M. R. Wade^9)
 
1) University of Wisconsin-Madison, Madison, WI, United States of America
²⁾ General Atomics, San Diego, California, USA
³⁾ University of California, Los Angeles, California, USA
⁴⁾ Association Euratom-CEA sur la Fusion, Cadarache, France
⁵⁾ Lehigh University, Bethlehem, Pennsylvania, USA
⁶⁾ University of California, San Diego, California, USA
⁷⁾ University of Texas-Austin, Austin, Texas, USA
⁸⁾ University of Alberta, Edmonton, Alberta, Canada
⁹⁾ Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA

Abstract.  Plasma turbulence characteristics, including radial correlation lengths, decorrelation times, amplitude profile, and flow velocity, have been measured during a $\rho^{*}_{}$ scan on DIII-D while all other transport-relevant dimensionless quantities ( $\beta$,$\nu^{*}_{}$,$\kappa$, q, T_e/T_i ...) are held nearly constant. The turbulence is measured by examining the correlation properties of the local long-wavelength ( k_$\perp$$\rho_{\mathrm{I}}^{}$ $\leq$ 1) density fluctuations, measured with beam emission spectroscopy. The radial correlation length of the turbulence, L_{c, r}, is shown to scale with the local ion gyroradius, with L_{c, r} $\approx$ 5$\rho_{\mathrm{I}}^{}$, while the decorrelation times scale with the local acoustic velocity as $\tau_{\mathrm{c}}^{}$ $\sim$ a/c_s. The turbulent diffusivity parameter, D $\sim$ (L_{c, r}²/$\tau_{\mathrm{c}}^{}$), scales in a roughly gyro-Bohm-like fashion, as predicted by the gyrokinetic equations governing turbulent transport. The experimental one-fluid power balance heat diffusivity scaling and that from GLF23 modeling compare reasonably well.

Read the full paper in PDF format.