NOISE INDUCED CHANGE IN THE DYNAMICS OF ANODIC DOUBLE LAYERS

摘要

Anodic double layer instabilities are observed in a diffusion filament-type discharge plasma by applying a positive biasing to an additional electrode. They show the characteristic behaviour of an excitable system consisting of spiking. The inter-spike statistics of the experimental dynamics as function of the values of the biasing potential shows a minimum, a rather unusual situation. We propose a computational model which is able to account for this behaviour. The model essentially takes into consideration the noise which is always present in the plasma of electrical discharges. We consider that the changing of the additional electrode potential has two effects: first, it can alter the behaviour of the anodic double layer inducing changes between highly nonlinear oscillator and excitable dynamics and second, the increasing of the biasing potential is associated to an enhancement of the noise level. The results of the model are in good agreement with the experiment.