  The aim of the study is to analyze the stability of the Energetic Particle
Modes (EPM) and Alfven Eigenmodes (AE) in Helitron J and LHD plasma if the
electron cyclotron current drive (ECCD) is applied. The analysis is performed
using the code FAR3d that solves the reduced MHD equations describing the
linear evolution of the poloidal flux and the toroidal component of the
vorticity in a full 3D system, coupled with equations of density and parallel
velocity moments for the energetic particle (EP) species, including the effect
of the acoustic modes. The Landau damping and resonant destabilization effects
are added via the closure relation. The simulation results show that the n=1
EPM and n=2 Global AE (GAE) in Heliotron J plasma can be stabilized if the
magnetic shear is enhanced at the plasma periphery by an increase (co-ECCD
injection) or decrease (ctr-ECCD injection) of the rotational transform at the
magnetic axis iota0. In the ctr-ECCD simulations, the EPM/AE growth rate
decreases only below a given iota0, similar to the ECCD intensity threshold
observed in the experiments. In addition, ctr-ECCD simulations show an
enhancement of the continuum damping. The simulations of the LHD discharges
with ctr-ECCD injection indicate the stabilization of the n=1 EPM, n=2 Toroidal
AE (TAE) and n=3 TAE, caused by an enhancement of the continuum damping in the
inner plasma leading to a higher EP beta threshold with respect to the co- and
no-ECCD simulations.
