TJ-II: On the electrostatic transport driven by Alfvén modes and broadband turbulence in the plasma edge region of the TJ-II stellarator: Difference between revisions

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The importance of quasi-coherent modes on transport is a growing area of research due its possible role in the development of reactor relevant scenarios. HIBP measurements have provided direct measurements of core ExB transport induced by AEs in the TJ-II stellarator <ref> A. Melnikov et al., Nucl. Fusion 50, 084023 (2010)</ref>. It was found that the AEs contribution to the frequency resolved turbulent particle transport constitutes a significant fraction of the total flux. Interestingly although most of the AEs contribute to outwards ExB flux some modes produce inward flux.
The importance of quasi-coherent modes on transport is a growing area of research due its possible role in the development of reactor relevant scenarios. HIBP measurements have provided direct measurements of core ExB transport induced by AEs in the TJ-II stellarator <ref> A. Melnikov et al., Nucl. Fusion 50, 084023 (2010)</ref>. It was found that the AEs contribution to the frequency resolved turbulent particle transport constitutes a significant fraction of the total flux. Interestingly although most of the AEs contribute to outwards ExB flux some modes produce inward flux.


Recently edge probes measurements have shown that shown that electrostatic turbulence and AEs driven transport are comparable in magnitude. Whereas the turbulent transport keeps always the same radially outwards propagation, AEs can be inwards or outwards depending of the NBI co-counter configuration. In addition, edge biasing is capable to module the amplitude of ExB transport driven by plasma turbulence but has a minor impact on the ExB transport driven by AEs. These results highlight the key role of the cross-phase between density and electric field fluctuations to control the level of ExB driven transport  
Recently edge probes measurements that shown that electrostatic turbulence and AEs driven transport are comparable in magnitude. Whereas the turbulent transport keeps always the same radially outwards propagation, AEs can be inwards or outwards depending of the NBI co-counter configuration. In addition, edge biasing is capable to module the amplitude of ExB transport driven by plasma turbulence but has a minor impact on the ExB transport driven by AEs. These results highlight the key role of the cross-phase between density and electric field fluctuations to control the level of ExB driven transport  


The goal of this proposal is to expand the present database of ExB turbulent transport driven by AEs.
The goal of this proposal is to expand the present database of ExB turbulent transport driven by AEs.
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