Abstract
Arc discharges increase the mass of the anode in a contact field. However, contact losses decrease the mass of the cathode, which is made of current-collecting materials in a rail field. Conducting careful experiments with the focus on proper changes in arc duration make it possible to notice clear differences among the volumes of the molten material, the surface concave of contact wire on the anode, and the molten-metal bridge. The authors analyzed the differences because the mechanism in the rail field is not the same as that in the contact field but the mechanism is related to the material decrease in the rail field. The Phenomena observed between the anode and the cathode from the start to approximately 10ms during the arc duration can be clarified by taking the aforementioned differences into account. Understanding the phenomena makes it possible to explain the decrease in the current-collecting materials. The paper presents the concave measurement results of the contact wire and the phenomena observed between the electrodes from the start to approximately 10ms during the arc duration.
