Co-toroidal plasma rotation with electron cyclotron power in DIII-D

RF electron heating and current drive in DIII-D are observed to typically reduce the core toroidal rotation velocity and core ion temperature when added to target discharges with rotation established by neutral beam heating. Two cases are noted here in which electron cyclotron heating and current drive are observed to increase co-toroidal rotation in different discharge regimes. In the first case electron cyclotron current drive (ECCD) is used to stabilize a 3/2 neoclassical tearing mode (NTM) and the stabilization is accompanied by an increase in rotation, ion temperature and plasma beta. In the second case electron cyclotron heating (ECH) added to a nominally Ohmic target discharge results in an increase in the co-toroidal rotation.