Abstract
Cathodic arcs (CA) are important across a wide range of applications including thin film deposition and solid fuel space propulsion. Understanding how cathode spots (CSs) move in magnetic fields has important implications for the deposition rates and thrust delivered as well as cathode/fuel usage efficiency. In this work, we investigated the dynamics of cathode spot (CS) motion in the presence of various axial magnetic fields (AMFs) in a high-current multi-spot CA system. Two photography techniques were used (i) long exposure and (ii) high-speed framing photography. The long-exposure images of cathode spots suggested that the cathode spots do not travel in spiral paths produced by Robson drift, as observed in previous vacuum interrupter system experiments. The reduced prevalence of Robson drift was found to be insufficiently explained considering only anodic plasma emission difference arising from the annular anode geometrical setup. High-speed framing images of cathode spots during discharges revealed a statistically significant reduction of the speed of cathode spot motion, as characterized by a decrease in K value as the applied AMF increases.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
