Skip navigation
Please use this identifier to cite or link to this item:
Title: Suppression of Alfvén modes on NSTX-U with outboard beam injection
Contributors: Fredrickson, E.D.
Belova, E.V.
Battaglia, D.J.
Bell, R.E.
Crocker, N.A.
Darrow, D.S.
Diallo, A.
Gerhardt, S.P.
Gorelenkov, N.N.
LeBlanc, B.P.
Podesta, M.
U. S. Department of Energy contract number DE-AC02-09CH11466
Keywords: Global Alfven Eigenmodes
Energetic particles
Issue Date: Jun-2017
Publisher: Princeton Plasma Physics Laboratory, Princeton University
Related Publication: Physical Review Letters, vol. 118, p. 265001 (June 2017)
Abstract: In this paper we present data from experiments on NSTX-U where it is shown for the first time that small amounts of high pitch-angle beam ions can strongly suppress the counter-propagating Global Alfvén Eigenmodes (GAE). GAE have been implicated in the redistribution of fast ions and modification of the electron power balance in previous experiments on NSTX. The ability to predict the stability of Alfvén modes, and developing methods to control them, is important for fusion reactor like the International Tokamak Experimental Reactor (ITER) which are heated by a large population of non-thermal, super-Alfvénic ions consisting of fusion generated alphas and beam ions injected for current profile control. We present a qualitative interpretation of these observations using an analytic model of the Doppler-shifted ion-cyclotron resonance drive responsible for GAE instability which has an important dependence on k⊥ρL. A quantitative analysis of this data with the HYM stability code predicts both the frequencies and instability of the GAE prior to, and suppression of the GAE after the injection of high pitch-angle beam ions.
Referenced By: 10.1103/PhysRevLett.118.265001
Appears in Collections:NSTX-U

Files in This Item:
File Description SizeFormat 
ARK_DATA.zip3.17 MBUnknownView/Download

Items in Dataspace are protected by copyright, with all rights reserved, unless otherwise indicated.