TJ-II: Why fast reaction of plasma fluctuations to ECRH ?
Experimental campaign
2019 Autumn
Proposal title
Why fast reaction of plasma fluctuations to ECRH?
Name and affiliation of proponent
Carlos Hidalgo
Details of contact person at LNF
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Description of the activity
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 [1] and the role of plasma gradient driven instabilities [2].
From the experimental perspective the goal is the investigation of the influence of ECRH on / off power heating power in the dynamics of edge & core fluctuations and transport and model validation including: 1) Level of fluctuations, 2) Phase relation between density and potential fluctuations, 3) Turbulent ExB transport.
International or National funding project or entity
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Description of required resources
Required resources:
- Number of plasma discharges or days of operation:
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- Type of plasmas (heating configuration):
- 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
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