Modelling of LHCD in high magnetic field, high density tokamak configuration.

Abstract

New modelling results (performed by means of "Raystar" code, a 2D ray-tracing-Fokker-Planck numerical tool) are presented with the aim of assessing the radial LH-driven current profiles in tokamak devices characterized by high density and high magnetic field as recently proposed by MIT. The modelling calculation is performed as function of plasma and antenna parameters, in particular the peak n//, the width of the launched RF power spectrum, the coupled power, the launched position of the antenna (high field side injection) and the kinetic profiles. Moreover by launching LH antenna spectra with a suitable n// width the power spectrum propagating in the plasma is weakly modified by quasi-linear broadening effects. Non-linear interactions with plasma density fluctuations of the thermal background are also negligible, as well as the PI at the plasma edge. The LHCD efficiency has been calculated and correlated to these parameters. © Published under licence by IOP Publishing Ltd.