Edge/SOL characterization in the NSTX spherical tokamak
Abstract
The edge/SOL of NSTX has been investigated with a high temporal (1 ?s) and spatial (1.5 mm) resolution probe array in L-mode and H-mode discharges. The decay lengths of the density and temperature profiles in the SOL in L-mode are 4 cm and 12 cm respectively, independently of power. In H-mode the profile decay lengths are reduced considerably to 1-2 cm. The profile decay lengths shorten significantly to 2 cm in H-mode. Features of interest are: 1) The Te SOL profile is flat at ∼20 eV and highly fluctuating and, 2) the Te pedestal is shifted inwards from the Ne pedestal by ∼3 cm, indicating decoupled energy and particle transport. Strong intermittency in the edge/SOL has been observed and quantified using conditional averaging. UEDGE modeling is in progress.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 2004
- Bibcode:
- 2004APS..DPPCO3010B