Electron Heating in Tokamak LHCD Experiment

Collisional damping and Landau damping of the lower hybrid wave in LHCD experiment are analytically studied. For a medium size tokamak like HL-1M and HT-7 where typical central electron temperature is around 1 keV, electron heating via collisional damping could be relatively large, while the absolute damping rate is usually small. The mode conversion of the slow wave to the fast wave due to the downshift of parallel refractive index would lead to edge heating. A quasi-linear wave power damping is estimated for a full LH driven plasma which is an order of magnitude smaller than the experimentally injected wave power for plasma with Te around 1 keV.