Physics Design of the National Compact Stellarator Experiment

Neilson, G.H. ; Zarnstorff, M.C. ; Lyon, J.F. ; Team, the NCSX

Princeton University. Plasma Physics Laboratory.

关键词: Bootstrap Current;    Feedback;    70 Plasma Physics And Fusion Technology;    Stellarators;    Elongation;   

DOI  :  10.2172/796179
RP-ID  :  PPPL-3676.pdf
RP-ID  :  AC02-76CH03073
RP-ID  :  796179

美国|英语

来源: UNT Digital Library

【 摘 要 】

Compact quasi-axisymmetric stellarators offer the possibility of combining the steady-state low-recirculating power, external control, and disruption resilience of previous stellarators with the low-aspect ratio, high beta-limit, and good confinement of advanced tokamaks. Quasi-axisymmetric equilibria have been developed for the proposed National Compact Stellarator Experiment (NCSX) with average aspect ratio approximately 4.4 and average elongation approximately 1.8. Even with bootstrap-current consistent profiles, they are passively stable to the ballooning, kink, vertical, Mercier, and neoclassical-tearing modes for b > 4%, without the need for external feedback or conducting walls. The bootstrap current generates only 1/4 of the magnetic rotational transform at b = 4% (the rest is from the coils). Transport simulations show adequate fast-ion confinement and thermal neoclassical transport similar to equivalent tokamaks. Modular coils have been designed which reproduce the physics properties, provide good flux surfaces, and allow flexible variation of the plasma shape to control the predicted MHD stability and transport properties.