Selecting, Characterizing, and Acting on Drift Waves and Flute Modes Turbulence in a Low-{beta} Magnetized Plasma Column

Journal Article · Sun Jan 15 04:00:00 EST 2006 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2168817· OSTI ID:20797891

Bonhomme, G; Brochard, F; Gravier, E ^[1]; Oldenbuerger, S; Philipp, M ^[2]

---

1. LPMIA, UMR 7040 CNRS -Universite Henri Poincare, BP 239 - 54506 Vandoeuvre-les-Nancy cedex (France)
2. Universitaet des Saarlandes, Saarbruecken (Germany)

We report on experiments performed on the low-{beta} plasma device MIRABELLE. Using a limiter, we recently observed that when increasing the magnetic field strength transitions between various gradient driven instabilities occur. New thorough measurements allow to identify unambiguously three instability regimes. At low magnetic field the strong ErxB velocity shear drives a Kelvin-Helmholtz instability, whereas at high magnetic field drift waves are only observed. A centrifugal (Rayleigh-Taylor) instability is also observed in between when the poloidal velocity field is shearless and strong enough. A close connection is made between the ratio {rho}s /L perpendicular of the drift parameter to the radial density gradient length and each instability regime. The transition scenario from regular waves to turbulence was experimentally investigated. As for drift waves the transition from regular state to spatio-temporal chaos and turbulence follows the quasi-periodicity (or Ruelle-Takens-Newhouse) route. Eventually we present new results on the efficiency of control and synchronization methods on Kelvin-Helmholtz and Rayleigh-Taylor spatio-temporal chaos in comparison with drift waves.

• OSTI ID: 20797891
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 812; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHAOS THEORY
COMPARATIVE EVALUATIONS
CONTROL
FLUTE INSTABILITY
HELMHOLTZ INSTABILITY
LIMITERS
MAGNETIC FIELDS
PERIODICITY
PLASMA
PLASMA DENSITY
PLASMA DRIFT
PLASMA RADIAL PROFILES
RAYLEIGH-TAYLOR INSTABILITY
SHEAR
SYNCHRONIZATION
TURBULENCE