Theoretical study of the Alfven eigenmode stability in CFETR steady state discharges

Abstract The aim of this study is to analyze the stability Alfven eigenmodes (AE) in China Fusion Engineering Test Reactor (CFETR) plasma for steady state operations. analysis done using gyro-fluid code FAR3d including effect acoustic modes, EP finite Larmor radius damping effects and multiple energetic particle populations. Two high poloidal β scenarios are studied with respect location internal transport barrier (ITB) at r / a ≈ 0.45 (case A) 0.6 B). Both operation show narrow TAE gap between inner-middle region wide EAE all along radius. AE CFETR plasmas improves if ITB located inwards, case A, showing AEs lower growth rates B. rate smaller A because modes where stabilizing magnetic shear stronger Multiple populations (NBI driven + alpha articles) negligible although simulations B NBI on n = 1 BAE caused by α particles during thermalization process. If FLR included simulations, EAE/NAE decreases up 70%, particularly > 3 toroidal families. Low ( < 6) largest rates. On other hand, 6 15) triggered frequency range NAE, strongly damped effects.