Complex dynamics of a dc glow discharge tube: Experimental modeling and stability diagrams.

Eugenio Pugliese,Joana G Freire,Jason A C Gallas,Stefano Euzzor,Riccardo Meucci

doi:10.1038/srep08447

Abstract

We report a detailed experimental study of the complex behavior of a dc low-pressure plasma discharge tube of the type commonly used in commercial illuminated signs, in a microfluidic chip recently proposed for visible analog computing, and other practical devices. Our experiments reveal a clear quasiperiodicity route to chaos, the two competing frequencies being the relaxation frequency and the plasma eigenfrequency. Based on an experimental volt-ampere characterization of the discharge, we propose a macroscopic model of the current flowing in the plasma. The model, governed by four autonomous ordinary differential equations, is used to compute stability diagrams for periodic oscillations of arbitrary period in the control parameter space of the discharge. Such diagrams show self-pulsations to emerge remarkably organized into intricate mosaics of stability phases with extended regions of multistability (overlap). Specific mosaics are predicted for the four dynamical variables of the discharge. Their experimental observation is an open challenge.

Highlights

We report a detailed experimental study of the complex behavior of a dc low-pressure plasma discharge tube of the type commonly used in commercial illuminated signs, in a microfluidic chip recently proposed for visible analog computing, and other practical devices
In this work we explore the dynamical behavior of the plasma tube in the region of glow discharge
The object of our investigations is a plasma tube device of the type commonly used in commercial neon signs and other applications[10,11,12,13,14,15,16]

Summary

Introduction

We report a detailed experimental study of the complex behavior of a dc low-pressure plasma discharge tube of the type commonly used in commercial illuminated signs, in a microfluidic chip recently proposed for visible analog computing, and other practical devices. From a theoretical point of view, discharges have been traditionally described taking into account the complex processes involved in the plasma recombination and electric conductivity Such descriptions require the use of coupled partial differential equations involving spatial and time variables, the transport of momentum and energy of plasma components, the continuity equation, diffusion equation, Poisson equation, etc. One may consider a macroscopic volt-ampere characterization of the discharge, regarding the whole plasma as a nonlinear two-terminal component of an electric circuit Such approach removes spatial dependencies and reduces the mathematical description to a nonlinear set of coupled ordinary differential equations, a more easy problem to deal with. Detailed references about generation of lowand high-energy plasmas can be obtained, e.g., in the several specialized books[12,13,14,15,16]

Methods

Results

Conclusion