TJ-II: On the physics of the density limit: Difference between revisions

TJ-II: On the physics of the density limit (view source)

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 == Description of the activity ==
-Enter description here <ref>A. Einstein, Journal of Exceptional Results (2017)</ref>, including motivation/objectives and experience of the proponent (typically one-two pages)
+Motivation. Recent experiments in TJ-II have addressed the relation between the density limit (DL) and the formation of low frequency, coherent electrostatic fluctuations in NBI heated plasmas. Once the density limit is achieved, highly coherent low frequency (f < 10 kHz) fluctuations in plasma potential with a near-zero phase difference between distant probe signals were detected. The increase in the amplitude of low frequency Zonal Flows like structures near the DL is qualitatively correlated to the increase in the level turbulence and the negative values in the radial electric field <ref>D. Fernandez- Ruiz et al., Master Thesis 2021</ref>.
+From the theoretical perspective, it has been argued that the collapse of Zonal Flows could be linked to an increase of radial transport that can lead to edge cooling limiting the plasma density <ref>Singh & Diamond Nuclear Fusion 2021 (in press)</ref>.
+Goals. The goal of the present research proposal is twofold:
+. Explore edge turbulence spreading and SOL width as approaching the density limit
+. Explore whether edge biasing can affect the density limit by driving external edge sheared flows.
 == International or National funding project or entity ==