TJ-II: Why fast reaction of plasma fluctuations to ECRH ?: Difference between revisions

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== Description of the activity ==
== 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)
Enter description here <ref>A. Einstein, Journal of Exceptional Results (2017)</ref>, including motivation/objectives and experience of the proponent (typically one-two pages)
Why do ERCH/ ICRH avoid core impurity accumulation?. Significant progress has been reported regarding the physics understanding of empirical actuators like core heating to avoid impurity accumulation, including the following mechanisms: 1) A reduction of the background density gradient, leading to a reduction of the inward (neoclassical) convection of impurities; 2) An increase of turbulent diffusion; 3) The amplification of core temperature screening which would be relevant in core alpha-heating regimes; 4) The development of core plasma potential flux surface asymmetries.
Why fast reaction of plasma fluctuations to ECRH?. This is the (challenging) question that we want to answer including experiments in TJ-II 2019 / 20, data analysis and model validation.
From the theoretical perpective we should consider two mechanisms:
The role of phase space driven instabilities <ref>S. Itoh and K. Itoh Scientific Reports 2, 860 (2012)</ref> and the role of plasma gradient driven instabilities <ref>Trapped Electron Modes (TEM) E. Sánchez et al., Nucl Fusion 59, 076029 (2019)</ref>.


== International or National funding project or entity ==
== International or National funding project or entity ==
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