Discrete Alfvén eigenmodes in the CFETR steady-state scenario

The stability features of discrete Alfvén eigenmodes ( α TAEs) trapped by α -induced potential wells are explored in the China Fusion Engineering Test Reactor (CFETR) advanced steady-state operation environment, where α denotes a measure of the pressure gradient. For the reversed magnetic shear (RS) H-mode scenario with an enhanced internal transport barrier (ITB), the α TAEs are trapped in the electron cyclotron (EC) power deposition region and the effects of different pedestals on α TAEs are analyzed. For the negative off-axis magnetic shear scenario, the α TAEs are discussed, and the effect of different magnetic shears on the α TAEs is presented. Finally, the effects of beam energies and pitch-angle distributions on α TAE stability are also presented.