TJ-II: Determination of the spatial periodicity of NBI-driven Alfvén Eigenmodes and study of its magnetic configuration dependence: Difference between revisions

From FusionWiki
Jump to navigation Jump to search
Line 32: Line 32:
== Description of required resources ==
== Description of required resources ==
Required resources:
Required resources:
* Two days of good NBI plasma operation (35 discharges each) with good plasma density control (this request usually means that the operation days mus be allocated close after the boron/lihium conditioning of the vacuum vessel.
* Two days of good NBI plasma operation (35 discharges each) with reasonably good plasma density control.
* Essential diagnostic systems:
* Essential diagnostic systems: Mirnov coils (helical and poloidal arrays) and CNPA measurements are mandatory. Besides the common shot to shot diagnostics (ECE, Thomson, Interferometry, Radiation), all systems providing edge plasma profiles are needed. If possible, Doppler Reflectometer, HIBP. MSE would also be desirable to evaluate configuration  changes induced by non-totally balanced currents.
* Type of plasmas (heating configuration):
* Type of plasmas (heating configuration): NBI (both injectors) and ECH.
* Specific requirements on wall conditioning if any:
* Specific requirements on wall conditioning if any: Good plasma density control usually means that the operation days must be allocated close after the boron/lihium conditioning of the vacuum vessel.
* External users: need a local computer account for data access: yes/no
* External users: need a local computer account for data access: no
* Any external equipment to be integrated? Provide description and integration needs:
* Any external equipment to be integrated? Provide description and integration needs:


Revision as of 17:35, 18 January 2022

Experimental campaign

Spring 2022

Proposal title

Determination of the spatial periodicity of NBI-driven Alfvén Eigenmodes and study of its magnetic configuration dependence.

Name and affiliation of proponent

Álvaro Cappa, CIEMAT. Pedro Pons, CIEMAT. Macarena Liniers, CIEMAT. Enrique Ascasíbar, CIEMAT.

Details of contact person at LNF

Enrique Ascasíbar, CIEMAT.

Description of the activity

MHD activity produced by Alfvén Eigenmodes (AEs) is routinely observed in NBI-heated TJ-II plasmas [1]. The results provided by recently installed sets of helical magnetic coils complement the previous experimental data and, together with advanced analysis tools like the 3D Lomb periodogram [2] allows the determination of the AEs spatial periodicity with an accuracy non reachable so far.

With this goal in mind we propose to study the alfvénic activity produced by both co and counter NBI injectors separately, as well as the one produced by simultaneous, balanced heating with both injectors (compensated plasma current). We plan to perform this study in at least two magnetic configurations, 100_44_64 (edge_iota 1.65) and 100_60_68 (1.77), looking for the expected influence of the configuration on the shear Alfvén spectrum.

Since we will be looking for reasonably stationary plasma density conditions to facilitate the mode analysis, we do not discard the use of moderate ECH heating during the NBI plasma phase.

International or National funding project or entity

International: EUROfusion Consortium under grant agreements 633053 (FP8) and 101052200 (FP9).

National: Spanish Ministry of Science and Innovation under grants FIS2017-88892-P and FIS2017-85252-R

Description of required resources

Required resources:

  • Two days of good NBI plasma operation (35 discharges each) with reasonably good plasma density control.
  • Essential diagnostic systems: Mirnov coils (helical and poloidal arrays) and CNPA measurements are mandatory. Besides the common shot to shot diagnostics (ECE, Thomson, Interferometry, Radiation), all systems providing edge plasma profiles are needed. If possible, Doppler Reflectometer, HIBP. MSE would also be desirable to evaluate configuration changes induced by non-totally balanced currents.
  • Type of plasmas (heating configuration): NBI (both injectors) and ECH.
  • Specific requirements on wall conditioning if any: Good plasma density control usually means that the operation days must be allocated close after the boron/lihium conditioning of the vacuum vessel.
  • External users: need a local computer account for data access: no
  • Any external equipment to be integrated? Provide description and integration needs:

Preferred dates and degree of flexibility

Preferred dates: (format dd-mm-yyyy)

References

  1. ↑ A. Cappa et al, Nuclear Fusion, 61(6):066019 (2021), and references therein
  2. ↑ S. Zegenhagen, et al., Plasma Physics and Controlled Fusion, 48(9):1333–1346 (2006)

Back to list of experimental proposals

Retrieved from "http://wiki.fusenet.eu/fusionwiki/index.php?title=TJ-II:_Determination_of_the_spatial_periodicity_of_NBI-driven_Alfvén_Eigenmodes_and_study_of_its_magnetic_configuration_dependence&oldid=7075"