Abstract:

Lower hybrid (LH) waves have been proved one of the most efficient methods of noninductive current drive (CD) and off-axis current profile control in tokamak experiments such as Tore Supra, TRIAM-IM, FTU, JET, JT-60U and HT-7. It is the key element of all the present devices addressing long pulse issues, as it exhibits the highest CD efficiency in present devices at low plasma temperatures. The off-axis current driven by the LH waves can create broad or even hollow current profiles required in an ‘advanced tokamak’ (AT) scenario by introducing negative magnetic shear. In order to have a commercial fusion reactor, the requirement of steady state operation of a tokamak is realized, for e.g in advanced tokamak operation modes. LH waves have been successfully utilized for electron and ion plasma heating as well as to sustain and ramp up toroidal plasma current for inductive flux saving needs. It is also used to stabilize sawteeth in tokamaks during LHCD experiments.

The talk will be focused on simulation results of 5 GHz LHCD efficiency for KSTAR tokamak. more