Electrostatic microturbulence in W7-X: comparison of local gyrokinetic simulations with Doppler reflectometry measurements
The first experimental campaigns of Wendelstein 7-X (W7-X) have shown that turbulence plays a decisive role in the performance of neoclassically optimized stellarators. This stresses the importance of understanding microturbulence from the theoretical and experimental points of view. To this end, th...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
IOP Publishing
2024
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| _version_ | 1811139571394543616 |
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| author | González-Jerez, A García-Regaña, J Calvo, I Carralero, D Estrada, T Sánchez, E Barnes, M |
| author_facet | González-Jerez, A García-Regaña, J Calvo, I Carralero, D Estrada, T Sánchez, E Barnes, M |
| author_sort | González-Jerez, A |
| collection | OXFORD |
| description | The first experimental campaigns of Wendelstein 7-X (W7-X) have shown that turbulence plays a decisive role in the performance of neoclassically optimized stellarators. This stresses the importance of understanding microturbulence from the theoretical and experimental points of view. To this end, this paper addresses a comprehensive characterization of the turbulent fluctuations by means of nonlinear gyrokinetic simulations performed with the code stella in two W7-X scenarios. In the first part of the paper, the amplitude of the density fluctuations is calculated and compared with measurements obtained by Doppler reflectometry (DR) in the OP1 experimental campaigns. It is found that the trend of the fluctuations along the radius is explained by the access of the DR system to different regions of the turbulence wavenumber spectrum. In the second part of the article, frequency spectra of the density fluctuations and the zonal component of the turbulent flow are numerically characterized for comparisons against future experimental analyses. Both quantities feature broad frequency spectra with dominant frequencies of O(1)–O(10) kHz. |
| first_indexed | 2024-09-25T04:08:12Z |
| format | Journal article |
| id | oxford-uuid:f0e7f0de-e267-4e42-9a1d-fbe98ef38034 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-09-25T04:08:12Z |
| publishDate | 2024 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | oxford-uuid:f0e7f0de-e267-4e42-9a1d-fbe98ef380342024-06-03T20:07:11ZElectrostatic microturbulence in W7-X: comparison of local gyrokinetic simulations with Doppler reflectometry measurementsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f0e7f0de-e267-4e42-9a1d-fbe98ef38034EnglishJisc Publications RouterIOP Publishing2024González-Jerez, AGarcía-Regaña, JCalvo, ICarralero, DEstrada, TSánchez, EBarnes, MThe first experimental campaigns of Wendelstein 7-X (W7-X) have shown that turbulence plays a decisive role in the performance of neoclassically optimized stellarators. This stresses the importance of understanding microturbulence from the theoretical and experimental points of view. To this end, this paper addresses a comprehensive characterization of the turbulent fluctuations by means of nonlinear gyrokinetic simulations performed with the code stella in two W7-X scenarios. In the first part of the paper, the amplitude of the density fluctuations is calculated and compared with measurements obtained by Doppler reflectometry (DR) in the OP1 experimental campaigns. It is found that the trend of the fluctuations along the radius is explained by the access of the DR system to different regions of the turbulence wavenumber spectrum. In the second part of the article, frequency spectra of the density fluctuations and the zonal component of the turbulent flow are numerically characterized for comparisons against future experimental analyses. Both quantities feature broad frequency spectra with dominant frequencies of O(1)–O(10) kHz. |
| spellingShingle | González-Jerez, A García-Regaña, J Calvo, I Carralero, D Estrada, T Sánchez, E Barnes, M Electrostatic microturbulence in W7-X: comparison of local gyrokinetic simulations with Doppler reflectometry measurements |
| title | Electrostatic microturbulence in W7-X: comparison of local gyrokinetic simulations with Doppler reflectometry measurements |
| title_full | Electrostatic microturbulence in W7-X: comparison of local gyrokinetic simulations with Doppler reflectometry measurements |
| title_fullStr | Electrostatic microturbulence in W7-X: comparison of local gyrokinetic simulations with Doppler reflectometry measurements |
| title_full_unstemmed | Electrostatic microturbulence in W7-X: comparison of local gyrokinetic simulations with Doppler reflectometry measurements |
| title_short | Electrostatic microturbulence in W7-X: comparison of local gyrokinetic simulations with Doppler reflectometry measurements |
| title_sort | electrostatic microturbulence in w7 x comparison of local gyrokinetic simulations with doppler reflectometry measurements |
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