TJ-II: Physics of transport decoupling, an approach to measure the phase relation between density and temperature fluctuations: Difference between revisions

 
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== Proposal title ==
== Proposal title ==
'''Physics of transport decoupling, an approach to measure the phase relation between density and temperature fluctuations'''
'''Physics of transport decoupling: an approach to measure the phase relation between density and temperature fluctuations'''


== Name and affiliation of proponent ==
== Name and affiliation of proponent ==
Igor Nedzelskiy (IST), Mark Koepke (UWV, Ulises Losada (Ciemat), Carlos Hidalgo (Ciemat)
IST (Igor Nedzelskiy, Carlos Silva), UWV (Mark Koepke), CIEMAT (Ulises Losada, Gregorio Martin, J. L. de Pablos, Carlos Hidalgo)


== Details of contact person at LNF ==
== Details of contact person at LNF ==
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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)


Why is there decoupling between particle and energy transport channels at the transition to improved confinement regimes?. Physics behind uncoupled transport channels is a relevant open question for understanding both ELM control techniques (e.g. using RMP) as part of the ITER base-line scenario and the development of plasma scenarios without ELMs (e.g. I-mode). Interestingly, uncoupled transport channels has been also reported in stellarators / heliotrons (e.g. TJ-II <ref> C. Hidalgo et al., PPCF 46 (2004) 287A </ref>).  
Why is there decoupling between particle and energy transport channels at the transition to improved confinement regimes?. Physics behind uncoupled transport channels is a relevant open question for understanding both ELM control techniques (e.g. using RMP) as part of the ITER base-line scenario and the development of plasma scenarios without ELMs (e.g. I-mode). Interestingly, uncoupled transport channels has been also reported in stellarators (e.g. TJ-II <ref> C. Hidalgo et al., PPCF 46 (2004) 287A </ref>).  


Transport channel decoupling could be driven by any mechanism that leads to a modification of the cross-phase between density and temperature fluctuations caused by changing driving conditions [ ].   
Transport channel decoupling could be driven by any mechanism that leads to a modification of the cross-phase between density and temperature fluctuations caused by changing driving conditions [<ref> C. Hidalgo et al., PPCF 59 (2017) 014051</ref>].   


 
We propose to measure the phase relation between density and temperature fluctuations using a combined diagnostic based on a Retarting Field Analyzer (RFA) <ref> I. Nedzelskiy et al., RSI 82 (2011) 043505</ref> and Langmuir probes that has been recently developed in the TJ-II stellarator.
We propose to measure the phase relation between density and temperature fluctuations using a combined Retarting Field Analyzer (RFA) and Langmuir probes that has been recently developed for TJ-II stellarator. Measurements of the phase relation will be compared with those obtained using baffle probes.


== International or National funding project or entity ==
== International or National funding project or entity ==
If applicable, enter funding here or write N/A
Eurofusion, DOE [US]


== Description of required resources ==
== Description of required resources ==
Required resources:
Required resources:
* Number of plasma discharges or days of operation:  
* Number of plasma discharges or days of operation: 2 days [one as Principal Investigator] 
* Essential diagnostic systems:
* Essential diagnostic systems: combined RFA + probe diagnostic
* Type of plasmas (heating configuration):
* Type of plasmas (heating configuration): ECRH
* Specific requirements on wall conditioning if any:
* Specific requirements on wall conditioning if any: standard TJ-II condicitions
* External users: need a local computer account for data access: yes/no
* External users: need a local computer account for data access: yes
* Any external equipment to be integrated? Provide description and integration needs:
* Any external equipment to be integrated? Provide description and integration needs:Installation of the RFA + probe diagnostic by mid-December in the reciprocating drive D


== Preferred dates and degree of flexibility ==
== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy)
Preferred dates: 16-12-2019 / 20-12-2019


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== References ==
== References ==
<references />  
<references />  

Latest revision as of 06:57, 11 October 2019

Experimental campaign

2019 Autumn

Proposal title

Physics of transport decoupling: an approach to measure the phase relation between density and temperature fluctuations

Name and affiliation of proponent

IST (Igor Nedzelskiy, Carlos Silva), UWV (Mark Koepke), CIEMAT (Ulises Losada, Gregorio Martin, J. L. de Pablos, Carlos Hidalgo)

Details of contact person at LNF

Carlos Hidalgo

Description of the activity

Why is there decoupling between particle and energy transport channels at the transition to improved confinement regimes?. Physics behind uncoupled transport channels is a relevant open question for understanding both ELM control techniques (e.g. using RMP) as part of the ITER base-line scenario and the development of plasma scenarios without ELMs (e.g. I-mode). Interestingly, uncoupled transport channels has been also reported in stellarators (e.g. TJ-II [1]).

Transport channel decoupling could be driven by any mechanism that leads to a modification of the cross-phase between density and temperature fluctuations caused by changing driving conditions [[2]].

We propose to measure the phase relation between density and temperature fluctuations using a combined diagnostic based on a Retarting Field Analyzer (RFA) [3] and Langmuir probes that has been recently developed in the TJ-II stellarator.

International or National funding project or entity

Eurofusion, DOE [US]

Description of required resources

Required resources:

  • Number of plasma discharges or days of operation: 2 days [one as Principal Investigator]
  • Essential diagnostic systems: combined RFA + probe diagnostic
  • Type of plasmas (heating configuration): ECRH
  • Specific requirements on wall conditioning if any: standard TJ-II condicitions
  • External users: need a local computer account for data access: yes
  • Any external equipment to be integrated? Provide description and integration needs:Installation of the RFA + probe diagnostic by mid-December in the reciprocating drive D

Preferred dates and degree of flexibility

Preferred dates: 16-12-2019 / 20-12-2019


References

  1. C. Hidalgo et al., PPCF 46 (2004) 287A
  2. C. Hidalgo et al., PPCF 59 (2017) 014051
  3. I. Nedzelskiy et al., RSI 82 (2011) 043505

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