View source for TJ-II: On the electrostatic transport driven by Alfvén modes and broadband turbulence in the plasma edge region of the TJ-II stellarator

== Experimental campaign ==
Spring 2022

== Proposal title ==
'''TJ-II: On the electrostatic transport driven by Alfvén modes and broadband turbulence in the plasma edge region of the TJ-II stellarator'''

== Name and affiliation of proponent ==

Igor Voldiner, Carlos Hidalgo
Laboratorio Nacional de Fusión, CIEMAT, Madrid, Spain

David Zarsoso, 
Marseille University, France

 Jacobo Varela, 
UC3M, Madrid, Spain

== Details of contact person at LNF ==
Igor Voldiner

== Description of the activity ==

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 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.

== International or National funding project or entity ==
Include funding here (grants, national plans)

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 2
* Essential diagnostic systems: edge probes (in feasible also HIBP)
* Type of plasmas (heating configuration): NBI co & counter configurations
* Specific requirements on wall conditioning if any:
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy)

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== References ==
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