Investigation of firing properties of a vacuum arcs triggered by plasma injection

The firing characteristic of a vacuum arc, by means of plasma injection, is described. In this method, a plasma, created from a trigger device, plumes away to the space between the cathode and anode. As the plasma is quasi-neutral, the electrostatic field is concentrated across the sheath at the surface of the cathode, thus, creating a high electrical field. As a result, a vacuum arc fires between the cathode and anode. The authors have investigated the firing rate as a function of the trigger cathode distance, trigger current, the anode-cathode distance and voltage. They found a firing rate between 90 to 100% for a trigger current in the range of 400-1200 A, the trigger pulse length was 4 ps, and the trigger-cathode distance was 1.6 to 3.6 cm. The anode cathode gap length changes the firing rate to a low extent for values between 2 to 5 cm. The anode cathode voltage do not change the firing rate. The effect of a magnetic field applied axially over the trigger have also been investigated. Using a version of a highly reliable trigger, the authors were able to deposit stainless steel, copper, carbon and molybdenum, thin films