Dependence of Intrinsic Rotation Reversals on Collisionality in MAST

Dependence of Intrinsic Rotation Reversals on Collisionality in MAST

Dependence of Intrinsic Rotation Reversals on Collisionality in MAST 150 150 Mathew
CCFE-PR(15)08

Dependence of Intrinsic Rotation Reversals on Collisionality in MAST

Tokamak plasmas rotate even without external injection of momentum. A Doppler backscattering system installed at MAST has allowed this intrinsic rotation to be studied in Ohmic L-mode and Hmode plasmas, including the first observation of intrinsic rotation reversals in a spherical tokamak. Experimental results are compared to a novel 1D model, which captures the collisionality dependence of the radial transport of toroidal angular momentum due to the effect of neoclassical flows on turbulent fluctuations. The model is able to accurately reproduce the change in sign of core toroidal rotation, using experimental density and temperature profiles from shots with rotation reversals as inputs and no free parameters fit to experimental data.

Collection:
Journals
Journal:
Nuclear Fusion
Publisher:
IOP
Published date:
02/01/2015