Testing Gyrokinetics on C-Mod and NSTX
Authors: M.H. Redi, W. Dorland, C.L. Fiore, D. Stutman, J.A. Baumgaertel, B. Davis, S.M. Kaye, D.C. McCune, J. Menard, and G. Rewoldt
Date of PPPL Report: June 2005
To be presented at: the Thirty-Second European Physical Society (EPS) Conference on Plasma Physics (EPS 2005), 27 June - 1 July 2005, Tarragona, Spain.
Quantitative benchmarks of computational physics codes against experiment are essential for the credible application of such codes. Fluctuation measurements can provide necessary critical tests of nonlinear gyrokinetic simulations, but such require extraordinary computational resources. Linear micro-stability calculations with the GS2 [1] gyrokinetic code have been carried out for tokamak and ST experiments which exhibit internal transport barriers (ITB) and good plasma confinement. Qualitative correlation is found for improved confinement before and during ITB plasmas on Alcator C-Mod [2] and NSTX [3], with weaker long wavelength micro-instabilities in the plasma core regions. Mixing length transport models are discussed. The NSTX L-mode is found to be near marginal stability for kinetic ballooning modes.