Turbulent Radial Correlation Lengths in the DIII-D Tokamak
Measurements of the radial correlation length Ar of density fluctuations have been made on the DIII-D tokamak in a variety of L-mode discharges. These measurements span the radial region 0.5 < {rho} < 1 and are found to scale approximately as {rho}{sub {theta},s} or 5-10 {rho}{sub s}. Here {rho}{sub {theta},s} is the poloidal ion Larmor radius calculated using local T{sub e} and poloidal magnetic field and {rho}{sub s} is the same except calculated using the total magnetic field. The {Delta}r data were obtained from a heterodyne reflectometer system. Comparisons to published analytic formulas of Ar have been carried out for a particular discharge condition. The measurements are found to be comparable in magnitude and radial dependence with a slab type formulation of ion temperature gradient (ITG) driven turbulence as well as an electron drift wave turbulence type prediction. Predictions from toroidal ITG and a different slab ITG model were found to be outside the error bars of the measurements. In addition, a detailed comparison to a non-linear gyro-kinetic turbulence code has begun. These and other similar comparisons are believed to be important as they serve to test and benchmark theory and codes as well as to help identify the type(s) of turbulence involved.
- Research Organization:
- General Atomics, San Diego, CA (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC03-99ER54463; FG03-86ER53225; FG03-95ER54292; FG03-96ER54373
- OSTI ID:
- 766721
- Report Number(s):
- GA-A23419; TRN: US0109345
- Resource Relation:
- Conference: 27th European Physical Society Conference on Controlled Fusion and Plasma Physics, Budapest (HU), 06/12/2000--06/16/2000; Other Information: PBD: 1 Aug 2000
- Country of Publication:
- United States
- Language:
- English
Similar Records
Modifications in turbulence and edge electric fields at the L--H transition in the DIII-D tokamak
Measurements of the cross-phase angle between density and electron temperature fluctuations and comparison with gyrokinetic simulations