Understanding High Harmonics Ion Cyclotron Heating Losses in the Scrape-of Layer of Tokamak Plasmas
Authors: N. Bertelli, et. al.
Abstract:
Full wave simulations of fusion plasmas show a direct correlation between the location of the fast-
wave cut-o , radiofrequency (RF) eld amplitude in the scrape-o layer (SOL) and the RF power
losses in the SOL observed in the National Spherical Torus eXperiment (NSTX). In particular,
the RF power losses in the SOL increase signi cantly when the launched waves transition from
evanescent to propagating in that region. Subsequently, a large amplitude electric eld occurs in
the SOL, driving RF power losses when a proxy collisional loss term is added. A 3D reconstruction of
absorbed power in the SOL is presented showing agreement with the RF experiments in NSTX. Loss
predictions for the future experiment NSTX-Upgrade (NSTX-U) are also obtained and discussed.
__________________________________________________
Submitted to: Physical Review Letters (November 2013)
__________________________________________________
Download PPPL-4966 (pdf 1.44 MB 5 pp)
__________________________________________________