The turbulent regime of a simple magnetized toroidal plasma column has been studied in the plasma device Thorello. The detection and the study of the spatio-temporal evolution of structures have been performed by means of conditional sampling techniques as well as other statistical tools. As a result the evidence of plasma blob formation and expulsion from the edge of the main plasma column has been obtained. The relation between structure phenomenology and statistical characteristics of the turbulent regime has been investigated. The motion of the density structures in the edge region of our device does not look ballistic but rather driven by the overall potential profile established in the turbulent state. Potential fluctuations are strongly anti-correlated with density structures, located in the same position and somewhat more extended. They provide a shallow potential well with a flat bottom and quite sharp edges surrounding and co-moving with the blobs. Blob lifetime exceeds the residence time associated with the overall E × B drift field. Then such persistent structures provide a means for a net convection of the charged particles to the limiter, across the magnetic field and beyond the edge region of the plasma.

Barni, R., & Riccardi, C. (2009). Advection of long lived density blobs in the turbulent state of a simple magnetized torus plasma. PLASMA PHYSICS AND CONTROLLED FUSION, 51(8), 1-19 [10.1088/0741-3335/51/8/085010].

Advection of long lived density blobs in the turbulent state of a simple magnetized torus plasma

BARNI, RUGGERO;RICCARDI, CLAUDIA
2009

Abstract

The turbulent regime of a simple magnetized toroidal plasma column has been studied in the plasma device Thorello. The detection and the study of the spatio-temporal evolution of structures have been performed by means of conditional sampling techniques as well as other statistical tools. As a result the evidence of plasma blob formation and expulsion from the edge of the main plasma column has been obtained. The relation between structure phenomenology and statistical characteristics of the turbulent regime has been investigated. The motion of the density structures in the edge region of our device does not look ballistic but rather driven by the overall potential profile established in the turbulent state. Potential fluctuations are strongly anti-correlated with density structures, located in the same position and somewhat more extended. They provide a shallow potential well with a flat bottom and quite sharp edges surrounding and co-moving with the blobs. Blob lifetime exceeds the residence time associated with the overall E × B drift field. Then such persistent structures provide a means for a net convection of the charged particles to the limiter, across the magnetic field and beyond the edge region of the plasma.
No
Articolo in rivista - Articolo scientifico
Scientifica
52.35.Ra - Plasma Turbulence, 52.25.Xz - Magnetized Plasmas
English
Barni, R., & Riccardi, C. (2009). Advection of long lived density blobs in the turbulent state of a simple magnetized torus plasma. PLASMA PHYSICS AND CONTROLLED FUSION, 51(8), 1-19 [10.1088/0741-3335/51/8/085010].
Barni, R; Riccardi, C
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10281/7526
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