Data di Pubblicazione:
2021
Abstract:
The presence of magnetic island in the boundary of fusion devices is expected to strongly
affect the local plasma properties, inducing local flow velocity patterns and perturbing the
edge profiles as well as the transport properties. In particular the proximity to the island Xpoint
or O-point is found to induce both electrostatic and magnetic turbulence modulation,
with experimental evidences in different magnetic configurations. The boundary of the W7-X
stellarator experiment is characterized by the presence of a poloidal chain of magnetic islands,
whose features depend on the magnetic configuration as defined by the rotational transform,
?/2?. These islands intercept the divertor plates and provide a poloidal series of X-points
constituting the island divertor, the concept exploited in the W7-X for the particle and energy
exhaust.
In this contribution the presence and features of turbulent fluctuations in both electrostatic and
magnetic quantities, including the parallel current density fluctuations will be investigated in
the Scrape-Off-Layer region of W7-X experiment. To this end a specifically designed
insertable probe head was constructed within the framework of EUROfusion WP.S1 work
package in collaboration between Consorzio RFX, IPP Greifswald and Forschungszentrum
Jülich. The probe head, named High Resolution Probe (HRP) [1,2], was conceived to be
installed on the mid-plane multi-purpose fast reciprocating manipulator on W7-X and is
suitable for the study of electrostatic and magnetic properties of filaments emerging from
turbulence background and characterizing the edge region.
In particular the magnetic island related turbulence modulation and the filamentary structure
population distribution will be analysed by applying advanced statistical tools
First measurements were performed during the W7-X experimental campaign OP1.2b, where
in particular the probe was exploring different magnetic configurations. The respective
features of the electromagnetic turbulence will be compared.
Tipologia CRIS:
04.02 Abstract in Atti di convegno
Keywords:
stellarator experiment W7-X; magnetic island in the boundary of nuclear fusion; magnetic and electrostatic turbulence island modulation
Elenco autori:
Martines, Emilio; Ghiraldelli, Raffaele; Vianello, Nicola; Spolaore, Monica; Agostinetti, Piero
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