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Article Dans Une Revue Plasma Physics and Controlled Fusion Année : 2016

The non-linear evolution of the tearing mode in electromagnetic ă turbulence using gyrokinetic simulations

W. A. Hornsby
  • Fonction : Auteur
R. Buchholz
  • Fonction : Auteur
S. Grosshauser
  • Fonction : Auteur
A. Ă Weikl
  • Fonction : Auteur
E. Poli
  • Fonction : Auteur
A. Ă G. Peeters
  • Fonction : Auteur

Résumé

The non-linear evolution of a magnetic island is studied using the ă Vlasov gyro-kinetic code GKW. The interaction of electromagnetic ă turbulence with a self-consistently growing magnetic island, generated ă by a tearing unstable Delta' > 0 current profile, is considered. The ă turbulence is able to seed the magnetic island and bypass the linear ă growth phase by generating structures that are approximately an ion ă gyro-radius in width. The non-linear evolution of the island width and ă its rotation frequency, after this seeding phase, is found to be ă modified and is dependent on the value of the plasma beta and ă equilibrium pressure gradients. At low values of beta the island evolves ă largely independent of the turbulence, while at higher values the ă interaction has a dramatic effect on island growth, causing the island ă to grow exponentially at the growth rate of its linear phase, even ă though the island is larger than linear theory validity. The turbulence ă forces the island to rotate in the ion-diamagnetic direction as opposed ă to the electron diamagnetic direction in which it rotates when no ă turbulence is present. In addition, it is found that the mode rotation ă slows as the island grows in size.

Dates et versions

hal-01465030 , version 1 (10-02-2017)

Identifiants

Citer

W. A. Hornsby, P. Migliano, R. Buchholz, S. Grosshauser, A. Ă Weikl, et al.. The non-linear evolution of the tearing mode in electromagnetic ă turbulence using gyrokinetic simulations. Plasma Physics and Controlled Fusion, 2016, 58 (1, SI), ⟨10.1088/0741-3335/58/1/014028⟩. ⟨hal-01465030⟩
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