0000000000278382
AUTHOR
Philippe Testé
Experimental approach of the interaction between a sub-microscopic cathode tip and the plasma
The interaction between electrical arc and cathode represents a crucial problem in the conception of arc jet thrusters, circuit breakers, and plasma torch or arc heaters. At the cathode surface, the current and energy transfers are controlled by the current emitting site (cathodic spot). Theories and experimental observations, at macroscopic and mesoscopic scale, deal with the erosion of the cathodic surface. Under micrometer range, theories refer to the arc root to describe the erosion of the surface. The works presented here propose an original method to evaluate the arc-cathode interaction at micrometric scale. A nanotechnology is used in order to control the roughness of the electrode s…
Influence of the tip effect of a carbon nanostructure on low current electrical arc initiation
During their setting off, circuit breakers and vacuum switch devices are accompanied by an electric arc whose physical and chemical properties are governed by emissive current sites at the cathode surface called cathode spots. Assuming the continuity of the current on the cathode surfaces, the cathode spots contribute to supply the electrical arc by electron emission and material ejection. Thus they cause erosion on the contact electrodes inducing a dysfunction of contactors. The apparition of these cathode spots is due essentially to dust particles and surface irregularities at different scales. This experimental work represents a contribution to the understanding of the electrical arc beh…