Parallel flows and turbulence in a linear plasma machine

Abstract

Experimental evidence of parallel flows dynamically coupled to radial turbulent transport is reported in a linear plasma machine (SLPM). Probability density functions (PDFs) for parallel flows and transport are different. PDFs for transport show clear non-gaussian features with large and sporadic bursts and PDFs of parallel flows are rather gaussian. Plasma profiles of parallel Mach number (in the range 0.1-0.3) show gradients dM || /dr comparable to 1/L n . Experimental results show that the dynamical coupling between transport and flows shows differences at different plasma radii. The degree of coupling also shows variations with plasma heating conditions. These findings suggest that, although turbulence can be considered as quasi-bidimensional in magnetized plasmas, parallel dynamics still play an important role in the regulation of radial transport.

Three-dimensional global fluid simulations of cylindrical magnetized plasmas

“…Magnetized plasma in a cylindrical geometry is probably the most basic configuration for magnetized laboratory plasma devices. Typical examples are KIWI, 1 MIRABELLE, 2 LAPD ͑Large Plasma Device͒, 3 the Auburn ALEXIS device ͑Auburn Linear Experiment for Instability Studies͒, 4 SLPM ͑Santander Linear Plasma Machine͒, 5 CSDX ͑Controlled Shear Decorrelation Experiment͒, 6,7 and VINETA, 8 to name only a few. The dynamics in these kind of plasma experiments is dominated by the presence of plasma sources and sinks.…”

Configuration of Flows in a Cylindrical Plasma Device

“…To understand the configuration of particle sources and sinks in the device, further measurements are needed, particularly along the magnetic axis. Moreover, indications of an interaction between parallel dynamics and radial transport in another linear device [16] show the importance of detailed studies of dynamic evolution of flow and particle transport in multiple dimensions. As a first step, temporal evolution and frequency spectrum of axial flow have been compared to plasma fluctuations.…”

Intermittency, avalanche statistics, and long-term correlations in a turbulent plasma

“…The vessel is located inside a circular waveguide of 0.08 m in diameter. Further details can be found in [31]. A magnetized plasma is produced by launching longitudinally electromagnetic waves with a frequency doi:10.1088/1742-5468/2013/04/P04022 f = 2.45 GHz.…”