http://www.cnr.it/ontology/cnr/individuo/prodotto/ID246070

Impact of helical boundary conditions on nonlinear 3D magnetohydrodynamic simulations of reversed-field pinch (Articolo in rivista)

Type

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

Label

Impact of helical boundary conditions on nonlinear 3D magnetohydrodynamic simulations of reversed-field pinch (Articolo in rivista) (literal)

Anno

2013-01-01T00:00:00+01:00 (literal)

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

10.1088/0741-3335/55/7/074015 (literal)

Alternative label

M. Veranda; D. Bonfiglio; S. Cappello; L. Chacón; D. F. Escande (2013)
Impact of helical boundary conditions on nonlinear 3D magnetohydrodynamic simulations of reversed-field pinch
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

M. Veranda; D. Bonfiglio; S. Cappello; L. Chacón; D. F. Escande (literal)

Pagina inizio

074015 (literal)

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

Article Number: 074015. La rivista è pubblicata anche online con ISSN 1361-6587. (literal)

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http://iopscience.iop.org/0741-3335/55/7/074015/ (literal)

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

55 (literal)

Rivista

Plasma physics and controlled fusion (Rivista)

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

8 (literal)

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

7 (literal)

Note

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

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

1 Consorzio RFX, Associazione Euratom-ENEA, Padova, Italy; - 2 Los Alamos National Laboratory, Los Alamos, USA; - 3 Laboratoire PIIM, UMR 6633 CNRS-Aix Marseille Université, France. (M. Veranda 1, D. Bonfiglio 1, S. Cappello 1, L. Chacón 2, D. F. Escande 3) (literal)

Titolo

Impact of helical boundary conditions on nonlinear 3D magnetohydrodynamic simulations of reversed-field pinch (literal)

Abstract

Helical self-organized reversed-field pinch (RFP) regimes emerge both numerically - in 3D visco-resistive magnetohydrodynamic (MHD) simulations - and experimentally, as in the RFX-mod device at high current (IP above 1 MA). These states, called quasi-single helicity (QSH) states, are characterized by the action of a MHD mode that impresses a quasi-helical symmetry to the system, thus allowing a high degree of magnetic chaos healing. This is in contrast with the multiple helicity (MH) states, where magnetic fluctuations create a chaotic magnetic field degrading the confinement properties of the RFP. This paper reports an extensive numerical study performed in the frame of 3D visco-resistive MHD which considers the effect of helical magnetic boundary conditions, i.e. of a finite value of the radial magnetic field at the edge (magnetic perturbation, MP). We show that the system can be driven to a selected QSH state starting from both spontaneous QSH and MH regimes. In particular, a high enough MP can force a QSH helical self-organization with a helicity different from the spontaneous one. Moreover, MH states can be turned into QSH states with a selected helicity. A threshold in the amplitude of MP is observed above which is able to influence the system. Analysis of the magnetic topology of these simulations indicates that the dominant helical mode is able to temporarily sustain conserved magnetic structures in the core of the plasma. The region occupied by conserved magnetic surfaces increases reducing secondary modes' amplitude to experimental-like values. (literal)

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