Linear and non-linear dynamics of Alfven Eigenmodes in Tokamaks

摘要

Linear and non-linear dynamics of various toroidicity induced global Alfven Eigenmodes is investigated by means of an initial value numerical code. The code uses the reduced magnetohydrodynamic (MHD) model expanded to the third order in the inverse aspect ratio parameter belonging to (belonging to(identical to) a/R(sub o)). Non-linear saturation is shown to occur due to the excitation of a perturbation to the non-linear mode structure, which dissipates energy on very short scales. In particular the non-linear saturation of the Toroidal Alfven Eigenmodes (TAE) and of the Resistive Periodic Shear Alfven Eigenmodes (RPSAE) due to MHD non-linearities is investigated and compared with analytical predictions.