http://www.cnr.it/ontology/cnr/individuo/prodotto/ID26309

Blob current structures in TORPEX plasmas: experimental measurements and numerical simulations (Articolo in rivista)

Type

Articolo in rivista (Classe)
Prodotto della ricerca (Classe)

Label

Blob current structures in TORPEX plasmas: experimental measurements and numerical simulations (Articolo in rivista) (literal)

Anno

2011-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.1088/0741-3335/53/12/124016 (literal)

Alternative label

I. Furno; C. Theiler; D. Lancon; A. Fasoli; D. Iraji; P. Ricci; M. Spolaore; N. Vianello (2011)
Blob current structures in TORPEX plasmas: experimental measurements and numerical simulations
in Plasma physics and controlled fusion (Print); IOP Publishing Ltd., Bristol BS1 6BE (Regno Unito)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

I. Furno; C. Theiler; D. Lancon; A. Fasoli; D. Iraji; P. Ricci; M. Spolaore; N. Vianello (literal)

Pagina inizio

124016 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#altreInformazioni

Article Number 124016, Part 1-2. La rivista è pubblicata anche online con ISSN 1361-6587 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#url

http://iopscience.iop.org/0741-3335/53/12/124016/ (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

53 (literal)

Rivista

Plasma physics and controlled fusion (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#note

Article Number 124016, Issue 12, Part 1-2 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#pagineTotali

15 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo

12 (literal)

Note

Scopu (literal)
ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

1 Centre de Recherches en Physique des Plasmas (CRPP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Association Euratom-Suisse, CH-1015 Lausanne, Switzerland 2 Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Corso Stati Uniti 4, 35127 Padova, Italy (I. Furno 1; C. Theiler 1; D. Lancon 1; A. Fasoli 1; D. Iraji 1; P. Ricci 1; M. Spolaore 2; N. Vianello 2) (literal)

Titolo

Blob current structures in TORPEX plasmas: experimental measurements and numerical simulations (literal)

Abstract

In the simple magnetized torus TORPEX, field-aligned blobs originate from ideal interchange waves and propagate radially outward due to del B and curvature induced drifts. Time-resolved two-dimensional measurements of the field-aligned current density J(parallel to) associated with blobs are obtained from conditionally sampled data from a single-sided Langmuir probe and a specially designed current probe. The profile of J(parallel to) exhibits an asymmetric dipolar structure, which originates from the polarization of the blob and is consistent with sheath boundary conditions. The asymmetry results from the non-linear dependence of J(parallel to) at the sheath edge upon the floating potential. Using internal measurements, we directly confirm the existence of two regimes, in which parallel currents to the sheath do or do not significantly damp charge separation and thus blob radial velocity. To investigate the effect of the observed asymmetry of J(parallel to) on the blob motion, we carried out numerical simulations of seeded blobs, using a two-field fluid model, which evolves electron density and vorticity. Simulations are performed spanning a wide range of blob sizes covering both regimes. We use either the complete or a linearized form for the sheath dissipation term in the vorticity equation. The structure of the parallel current density and plasma potential is found to be different in the two cases. Asymmetric profiles are observed in simulations with the complete form, while symmetric profiles are obtained when a linearized form is used. Negligible effects are, however, observed in terms of blob radial velocity. The relevance of the present results for fusion devices is also discussed. (literal)

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