Noise-invoked resonances near a homoclinic bifurcation in the glow discharge plasma

Abstract

Stochastic Resonance (SR) and Coherence Resonance (CR) have been studied experimentally in the discharge plasma close to a homoclinic bifurcation. For the SR phenomena, it is observed that a superimposed subthreshold periodic signal can be recovered via stochastic modulations of the discharge voltage. Furthermore, it is realized that even in the absence of a subthreshold deterministic signal, the system dynamics can be recovered and optimized using noise. This effect is defined as CR in the literature. In the present experiments, induction of SR and CR are quantified using the Absolute Mean Difference (AMD) and Normalized Variance (NV) techniques respectively. AMD is a new statistical tool to quantify regularity in the stochastic resonance and is independent of lag.

Long range temporal correlation in the chaotic oscillations of a dc glow discharge plasma

“…This is in contrast to what was observed in the previous experiments, 18 where the initial oscillations were chaotic but bifurcated to coherent relaxation oscillations beyond a threshold voltage and finally disappeared through homo clinic bifurcations. 17 have been due to the presence of an anode glow which was not present in the present experiments and also the aspect ratio of the cathode to the anode.…”

“…1. 17,18,20 It comprises a hollow cathode tube of length $17 cm and of diameter $9:0 cm, with a central wire of diameter $1:6 mm, and the complex temporal dynamics in the plasma floating potential fluctuations was monitored using a Langmuir probe. This assembly was mounted inside a vacuum chamber and was pumped down to a pressure of about $0:001 mbar and subsequently filled with argon gas up to a pressure $0:056 mbar.…”

Stochastic and Nonlinear Dynamics in Low-Temperature Plasmas

“…An example is the so-called alternating periodic chaotic (APC) sequence. Much of the behavior concerning APC sequences is understood in terms of a homoclinic chaotic scenario [44]. Homoclinic orbits are associated with erratic behavior (chaos) in a dynamical system [45].…”

Study of nonlinear oscillations in a glow discharge plasma using empirical mode decomposition and Hilbert Huang transform

“…1,2 Nonlinear phenomena are generally studied using a variety of analysis methods such as nonlinear time series analysis and spectral analysis. Only a global idea about the system can be obtained from common nonlinear time series analysis techniques such as estimation of fractal dimension, correlation dimension, and Lyapunov exponent.…”