Abstract
: Resonant magnetic perturbations (RMPs) have been shown to successfully suppress edge localized modes (ELMs) in the DIII-D tokamak. A previous study of target plate conditions highlighted differences in RMP discharges between low and high electron collisionality, nu(e)(sic), operation in DIII-D. This paper reports on a systematic study of the electron density pump-out associated with the turn-on of the RMP over a wide range of operating conditions in DIII-D, including shapes and collisionalities similar to those anticipated in ITER. It is shown that the pump-out magnitude, Delta n(e), has an upper envelope that is inversely proportional to the pedestal nu(e)(sic). The particle decay times, which are calculated based on global D(2) particle balances, show an increase as the pedestal nu(e)(sic) is increased. Both results are suggestive that the underlying physics mechanism is an increase in edge particle transport and/or that wall depletion is playing a role in the pump-out magnitude. (C) 2009 Elsevier B.V. All rights reserved.
