ICRF Mode Conversion Flow Drive on Alcator C-Mod and Projections to Other Tokamaks

Abstract

Plasma flow drive via ICRF mode conversion (MC) has been demonstrated on Alcator C-Mod. The toroidal rotation in these D([superscript 3]He) MC plasmas is typically more than twice above the empirically determined intrinsic rotation scaling in ICRF minority heated plasmas. In L-mode plasmas at 3 MW ICRF power input, up to 90 km/s toroidal rotation and 2 km/s localized ( r/a~0.4) poloidal rotation has been observed. The MC ion cyclotron wave (ICW) was detected by a phase contrast imaging system in heterodyne setup. Through TORIC 2-D full wave simulation, and comparison with other experimental evidence, we hypothesize that the interaction between the MC ICW and the [superscript 3]He ions may be the mechanism for the observed MC flow drive. TORIC simulation suggests that similar flow drive scenario may be realized on JET D(3He) plasmas. The promising scenarios on ITER are the inverted minority scenario (T)D and high field launch for T-D-([superscript 3]He) plasma. In non-radioactive phase, these correspond to ([superscript 3]He)-H and [superscript 4]He([superscript 3]He) plasmas respectively.