Fluctuations and Intermittent Transport in Single and Multiple Entangled Magnetized Plasma Pressure Filaments

The origin of intermittent fluctuations in an experiment involving several interacting electron plasma pressure filaments in close proximity, embedded in a large linear magnetized plasma device, is investigated. The intermittent character of the fluctuating temperature and electric potential is caused by radially and azimuthally propagating turbulent structures that originate from pressure gradient-driven drift-Alfven instabilities near the edges of the filament bundle. The probability density function (PDF) of the fluctuations obtained from the Langmuir probe data is established to be non-Gaussian and the time series contains uncorrelated Lorentzian pulses. This is suggestive of deterministic chaos in the underlying dynamics which is supported by the complexity-entropy (CH-plane) analysis of the time series. Furthermore, application of rescaled adjusted range (R/S) statistics to the time series reveals a double Hurst exponent, one associated with the behaviour of shorter time scale phenomena such as the Lorentzian pulses and intermittency, and the second connected to the longer time scales of density, temperature and vorticity mixing in the interacting filaments. Basic features of this nonlinear dynamical system are captured in a 3D gyrokinetic simulation of the filament-filament interaction.