X-Point-Position-Dependent Intrinsic Toroidal Rotation in the Edge of the TCV Tokamak

Phys Rev Lett. 2015 Jun 19;114(24):245001. doi: 10.1103/PhysRevLett.114.245001. Epub 2015 Jun 17.

Abstract

Edge intrinsic rotation was investigated in Ohmic L-mode discharges on the Tokamak à Configuration Variable, scanning the major radial position of the X point, R(X). Edge rotation decreased linearly with increasing R(X), vanishing or becoming countercurrent for an outboard X point, in agreement with theoretical expectations. The core rotation profile shifted fairly rigidly with the edge rotation, changing the central rotation speed by more than a factor of two. Core rotation reversals had little effect on the edge rotation velocity. Edge rotation was modestly more countercurrent in unfavorable than favorable ∇B shots.