  The aim of the present study is to analyze the saturation regime of the
Toroidal Alfven Eigenmodes (TAE) in the LHD plasma, particularly the MHD burst.
The linear and nonlinear evolution of the TAEs are simulated by the FAR3d code
that uses a reduced MHD model for the thermal plasma coupled with a gyrofluid
model for the energetic particles (EP) species. The linear simulations indicate
the overlapping of 1/2-1/1, 2/3-2/4 and 3/5-3/6 TAEs in the inner-middle plasma
region and frequency range of 45-75 kHz, triggered by EPs with an energy of Tf
= 45 keV and EP beta = 0.022. The nonlinear simulations show that 2/3-2/4 and
3/4-3/5 TAEs are further destabilized due to the energy transfer from 1/1-1/2
TAE, leading to a broad TAEs radial overlapping and the MHD burst triggering.
The energy of 1/1-1/2 TAE is also nonlinearly transferred to the thermal plasma
destabilizing the 0/0 and 0/1 modes, inducing the generation of shear flows and
zonal currents as well as large deformations in the thermal pressure and EP
density radial profiles. The nonlinear simulation reproduces the same
succession of instabilities and the same frequency range with respect to the
experiment. The instability propagates outward during the bursting phase,
showing a large decrease of the EP density profile between the middle-outer
plasma, pointing out the loss of part of the EP population that explains the
decrease of the plasma heating efficiency observed during the MHD burst.
