The paper gives a survey of numerical values of the most important parameters at the copper arc‐cathode root and in the cathode‐fall region. The radius and the temperature of the arc‐cathode root, the electron current fraction, the electric field, the thickness of the cathode‐fall region, and the atom density in this region are theoretically calculated and shown as a function of the arc current. Furthermore, there is a short section describing the suggestion that after neutralization of ions on the boiling surface of the cathode root, all of the resulting atoms may be reflected away into the cathode‐fall region.