Time resolved resonant laser diagnostics of the low current vacuum arc cathode spot

The resonant laser diagnostics combined with high speed IMACON 468 frame/streak camera was used as a technique for data acquisition. The experiments were performed with an arced vacuum gap formed by the capillary-type liquid-metal cathode and the plane anode in conditions of high oil-free vacuum. The evolution of observable cathode spot plasma is analysed in terms of cyclicity of the cathode spot operation.