Comparison Study of 2-D Images of Temperature Fluctuations during the Sawtooth Oscillation with Theoretical Models
Authors: H.K. Park, A.J.H. Donné, N.C. Luhmann, Jr., I.G.J. Classen, C.W. Domier, E. Mazzucato, T. Munsat, M.J. van de Pol, Z. Xia, and the TEXTOR team
Date of PPPL Report: April 2006
Submitted to: Physical Review Letters
High temporal and spatial resolution two-dimensional (2-D) images of electron temperature fluctuations were employed to study the sawtooth oscillation in TEXTOR tokamak plasmas. The 2-D images are directly compared to the expected 2-D patterns of the plasma pressure (or electron temperature) from various theoretical models. The observed experimental 2-D images are only partially in agreement with the expected patterns from each model: the image of the initial reconnection process is similar to that of the ballooning mode model. The intermediate and final stages of the reconnection process resemble those of the full reconnection model. The time evolution of the images of the hot spot/island is partially consistent to those from the full reconnection model, but is not consistent with those from the quasi-interchange model.