Study of EAST LH Antennas Coupling at ENEA-Frascati.

The two Lower Hybrid (LH) launchers of the EAST tokamak have been analysed using some tools available at ENEAFrascati research centre. The antennas, working at 2.45 and 4.6 GHz, have been assessed in terms of reflection coefficient and launched power spectrum for several plasma loads differing in the electron density profile. Fitting an experimental profile we derived a set of parameterised realistic density profiles to compute the coupling performances of different spectra, launched by considering different phasing between antenna modules. The sensitivity to the tilt of the magnetic field with respect to the equatorial plane as well as to an additional progressive phasing at the mouth due to the toroidal curvature has been studied too. The most suitable operational conditions for the minimization of reflected power and side lobes in the njj spectra are identified. [ABSTRACT FROM AUTHOR]