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Quasicoherent modes on the COMPASS tokamak

Publikace na Matematicko-fyzikální fakulta |
2015

Tento text není v aktuálním jazyce dostupný. Zobrazuje se verze "en".Abstrakt

Multiple quasicoherent electromagnetic modes with steady-state frequency and different nature and location were observed in the COMPASS tokamak (R = 0.56 m, = 0.2 m) at B-t = 1.14T with Co-NBI (P-NBI = 0.2-0.5 MW, E-b = 32 keV) at frequencies 5 kHz < f < 250 kHz. Modes were observed in both low and high confinement (L- and H-modes) plasmas.

Lower frequency modes with f < 50 kHz were identified as low m tearing and kink MHD modes, while higher frequency modes with 50 kHz < f < 250 kHz were considered as having Alfvenic nature. Unexpectedly, such modes were only observed in the H-mode, both in neutral beam injector-assisted and Ohmic, so the mode driving force is not yet clear.

Using the linear MHD code KINX, we initially identified the observed mode with a ballooning structure is as beta induced Alfven eigenmode (BAE) with m, n < 5, while an antiballooning mode is initially identified as toroidal Alfven eigenmode (TAE) with m, n < 9.