The procedure to estimate the average local temperature, density, and plasma potential by conditionally selecting points of the Langmuir probe characteristic curve is revised and applied to the study of intermittent bursts in the Texas Helimak and TCABR tokamak. The improvements made allow us to distinguish the burst temperature from the turbulent background and to study burst propagation. Thus, in Texas Helimak, we identify important differences with respect to the burst temperature measured in the top and the bottom regions of the machine. While in the bottom region the burst temperatures are almost equal to the background, the bursts in the top region are hotter than the background with the temperature peak clearly shifted with respect to the density one. On the other hand, in the TCABR tokamak, we found that there is a temperature peak simultaneously with the density one. Moreover, the radial profile of bursts in the top region of Helimak and in the edge and scrape-off layer regions of TCABR shows that in both machines, there are spatial regions where the relative difference between the burst and the background temperatures is significant: up to 25% in Texas Helimak and around 50% in TCABR. However, in Texas Helimak, there are also regions where these temperatures are almost the same.
Burst temperature from conditional analysis in Texas Helimak and TCABR tokamak
F. A. C. Pereira, W. A. Hernandez, D. L. Toufen, Z. O. Guimarães-Filho, I. L. Caldas, K. W. Gentle; Burst temperature from conditional analysis in Texas Helimak and TCABR tokamak. Phys. Plasmas 1 April 2018; 25 (4): 042301. https://doi.org/10.1063/1.5025062
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