Observations of central toroidal rotation in icrf heated alcator C-mod plasmas

摘要

Impurity toroidal rotation has been observed in the centre of Alcator C-Mod ion cyclotron range of frequencies(ICRF)heated plasmas, from the Doppler shifts of argon X ray lines. Rotation velocities greater than 1.2×10~7 cm/s(ω=200 krad/s)in the co-current direction have been Observed in H mode discharges that had no direct momentum input. There is a correlation between The increasing in the central impurity rotation velocity and the increase in the plasma stored energy (confinement enhancement), induced by ICRF heating, although other factors may be at play.