Ecton processes of low current vacuum arc imaged with streak technique

A copper vacuum arc cathode spot at current 3-12 A was imaged by streak camera with time resolution up to 0.7 ns and spatial resolution up to 2.9 μm. It was found that for copper at currents of two threshold current (3A) the most probable duration of ecton cycle is 15- 20 ns and the duration of phase of intense plasma production is 5 - 10 ns. As current rises the ectons having more long cycle duration and more long phase of intense plasma production appears, so that at current of eight threshold current (12 A) the most probable duration of ecton cycle is 50- 70 ns and the duration of phase of intense plasma production is 10-20 ns. The ectons with shortest cycle time still appears at 12 A current.