Trapped Electron Precession Shear Induced Fluctuation Decorrelation
Authors: T.S. Hahm, P.H. Diamond, and E.-J. Kim
Date of PPPL Report: July 2002
Presented at: the 29th EPS Conference on Plasma Physics and Controlled Fusion, June 17-21, 2002 Montreau, Switzerland
We consider the effects of trapped electron precession shear on the microturbulence. In a similar way the strong E X B shear reduces the radial correlation length of ambient fluctuations, the radial variation of the trapped electron precession frequency can reduce the radial correlation length of fluctuations associated with trapped electrons. In reversed shear plasmas, with the explicit dependence of the trapped electron precession shearing rate on Bq, the sharp radial gradient of Te due to local electron heating inside qmin can make the precession shearing mechanism more effective, and reduce the electron thermal transport constructing a positive feedback loop for the Te barrier formation.