Structure of the welding arc cathode spot with a nonconsumable electrode

The cathode spot autographs on a glass surface are investigated through an electron microscope, with a magnification up to $100\,000$. We discover that the welding arc cathode spot consists of separate cells with the substructure, current channels, $10$–$60$ nm in diameter. We acquire color photographs of the welding arc cathode spot with the cathode torch. Photograph processing through different filters reveals the shape of the cathode spot and the cathode torch. We perform the estimate calculations of the current density in the welding arc cathode spot substructure.