Arc erosion characteristics of W-fuzz samples with different thicknesses of the nanostructured layer

Abstract

An analysis of the results of measuring the erosion rates of W-fuzz samples with different fuzz thicknesses subject to arcing has been performed. Based on the examination of the structure of arc tracks, it has been concluded that a sharp increase in the erosion rate was accompanied by melting of the nanostructured layer. At the same time, numerous frozen droplets were observed at the boundary of the cathode spot track on the samples with a large fuzz thickness. Individual droplets were also found at some distance from the boundary. The experimental results have been interpreted theoretically using the explosive emission (ecton) model and the results of the analysis of thermal processes occurring in the cathode spot.

Keywords

• Unipolar arcing
• Erosion rate
• Divertor
• Fuzz layers