Intrinsic Noise Induced Coherence Resonance in a Glow discharge Plasma

TL;DR

This paper demonstrates how intrinsic noise in a glow discharge plasma can induce coherence resonance, with experimental and numerical evidence showing increased regularity of spikes as discharge voltage varies.

Contribution

It provides experimental evidence and a theoretical model showing noise-induced coherence resonance in glow discharge plasma, linking noise levels to spike regularity.

Findings

Regularity of spikes increases with discharge voltage

Noise component increases with discharge voltage

Numerical model agrees with experimental observations

Abstract

Experimental evidence of intrinsic noise induced coherence resonance in a glow discharge plasma is being reported. Initially the system is started at a discharge voltage (DV) where it exhibited fixed point dynamics, and then with the subsequent increase in the DV spikes were excited which were few in number and with further increase of DV the number of spikes as well as their regularity increased. The regularity in the interspike interval of the spikes is estimated using normalized variance (NV). Coherence resonance was determined using normalized variance curve and also corroborated by Hurst exponent and power spectrum plots. We show that the regularity of the excitable spikes in the floating potential fluctuation increases with the increase in the DV, upto a particular value of DV. Using a Wiener filter, we separated the noise component which was observed to increase with DV and hence conjectured that noise can be playing an important role in the generation of the coherence resonance. From an anharmonic oscillator equation describing ion acoustic oscillations, we have been able to obtain a FHN like model which has been used to understand the excitable dynamics of glow discharge plasma in the presence of noise. The numerical results agree quite well with the experimental results.