Multilayer structure of electrical conductivity for contact surface of railgun

The method how to avoid a high concentration of current density and to exclude the probability of electric arcing on the trailing edge of solid armature of railgun has been considered in the paper. Method is based on the variation of electrical conductivity in the contact surfaces of armature and rails. Longitudinal variation of conductivity in the skin-layer of rail in dependence on the local velocity of armature opens the possibility of electric arc suppression. This possibility is proved by analysis of magnetic flux linkage change at virtual displacement of armature. Concerning of electrical conductivity variation along direction perpendicular to the contact surface first in armature that is a way to improve the current density distribution along the contact. Reduction of conductivity at the surface layer of armature leads to the more favorable distribution of current density along the contact zone without its super high concentration at trailing edge of armature. It is confirmed by results of 2D numerical simulation of electromagnetic field in the zone contact at velocity of armature up to 2.5 km/s.