Toroidal Rotation and ICRF Heating in NBI-driven Discharges in JET

The addition of radio frequency heating to an NBI-driven target discharge is observed to reduce the toroidal rotation frequency. Experiments on this effect were performed on JET using (H)-D and (He3)-D minority ICRH (ion cyclotron resonance heating) to vary the bulk electron to ion heating ratio. However, to lowest order, there is no clear difference in the two heating scenarios. We apply a recent model based upon the degradation of confinement with auxiliary power, and find that these JET data are in reasonable agreement with it. (authors)