Robustness and flexibility in compact quasiaxial stellarators: Global ideal MHD stability and energetic particle transport

Redi, M.H. ; Diallo, A. ; Cooper, W.A. ; Fu, G.Y.

Princeton University. Plasma Physics Laboratory.

关键词: Pressure Dependence;    70 Plasma Physics And Fusion;    Stellarators;    Plasma Simulation;    Charged-Particle Transport;   

DOI  :  10.2172/750431
RP-ID  :  PPPL--3429
RP-ID  :  AC02-76CH03073
RP-ID  :  750431

美国|英语

来源: UNT Digital Library

【 摘 要 】

Concerns about the flexibility and robustness of a compact quasiaxial stellarator design are addressed by studying the effects of varied pressure and rotational transform profiles on expected performance. For thirty, related, fully three-dimensional configurations the global, ideal magnetohydrodynamic stability is evaluated as well as energetic particle transport. It is found that tokamak intuition is relevant to understanding the magnetohydrodynamic stability, with pressure gradient driving terms and shear stabilization controlling both the periodicity preserving, N=0, and the non-periodicity preserving, N=1, unstable kink modes. Global kink modes are generated by steeply peaked pressure profiles near the half radius and edge localized kink modes are found for plasmas with steep pressure profiles at the edge as well as with edge rotational transform above 0.5. Energetic particle transport is not strongly dependent on these changes of pressure and current (or rotational transform) profiles, although a weak inverse dependence on pressure peaking through the corresponding Shafranov shift is found. While good transport and MHD stability are not anticorrelated in these equilibria, stability only results from a delicate balance of the pressure and shear stabilization forces. A range of interesting MHD behaviors is found for this large set of equilibria, exhibiting similar particle transport properties.