Cathodic arc voltage noise modelling: ectons and random walk of the cathode spots

The noise signal of the voltage fluctuations of cathode arcs recorded at different sampling frequencies was analyzed. To explain obtained Fourier spectra for each measurement, a model was developed. The characteristics of the model were obtained by comparing Fourier spectra of the developed model and experimental signals. The model shows good quality agreement with the experiment. The voltage signal consists of two parts: a sum of very short (several ns) fluctuations, related a microexplosion or ecton and a low frequency part related to a random cathode spot walk.