Wave Driven Fast Ion Loss in the National Spherical Torus Experiment

Fredrickson, E.D. ; Cheng, C.Z. ; Darrow, D. ; Fu, G. ; Gorelenkov, N.N. ; Kramer, G. ; Medley, S.S. ; Menard, J. ; Roquemore, L. ; Stutman, D. ; White, R.B.

Princeton University. Plasma Physics Laboratory.

关键词: Thermonuclear Reactors;    Fishbone Instability;    Magnetic Fields;    Wavelengths;    70 Plasma Physics And Fusion Technology;   

DOI  :  10.2172/814739
RP-ID  :  PPPL-3851
RP-ID  :  AC02-76CH03073
RP-ID  :  814739

美国|英语

来源: UNT Digital Library

【 摘 要 】

The study of fast ion instabilities in conventional aspect ratio tokamaks is motivated in large part by their potential to negatively impact the ignition threshold in fusion reactors by causing fast ion losses. Spherical tokamak's (ST), with intrinsically low magnetic fields, are particularly susceptible to fast ion driven instabilities. The 3.5 MeV alpha's from the D-T [deuterium-tritium] fusion reaction in proposed ST reactors will have velocities much higher than the Alfven speed. The Larmor radius of the fusion alphas, normalized to the plasma size, will also be larger than for conventional aspect ratio tokamak reactors. The resulting longer wavelengths of the *AE instabilities will be more effective in driving fast ion loss. The change in magnetic topology also influences the mode structure, as in the case of the Compressional Alfven Eigenmodes (CAE) seen on NSTX.