UDC 537.523

M. Messaad1), A. W. Belarbi1), 
M. Abbaoui2), and A. Lefort2)

A SIMPLE MODEL FOR THE INTERACTION OF A LOW-CURRENT VACUUM ARC WITH A COPPER CATHODE
Experimental and theoretical studies of arc-cathode region have been made during several decades but the task is not yet completed, in spite of many efforts and progress. In this work, a numerical model describing the arc-cathode region is developed. The arc is treated as a steady-state phenomenon. The model is then applied to a vacuum arc discharge interacting with a Cu cathode at low current of 4-50 A. The model yields the temperature and electric field strength at the cathode surface, density of the current of the electrons emitted, total current density, cathode spot radius, different kinds of power densities in heating and cooling the cathode, and the plasma electron density. The comparison with experimental results shows good agreement. 1)Department of Electrotechnics, Faculty of Electrical Engineering, University of Science and Technology (USTO), P.O. 1505 - El-m'naouar, Oran, Algeria; E-mail: bmessaad@yahoo.fr; 2)Electric Arc and Thermal Plasmas Laboratory, Blaise Pascal University, 63177 Aubiиre, France. Original article submitted May 22, 2006.