On the mechanism of the vacuum arc voltage fall

Earlier it was believed that the cathode fall potential (which is the main part of the full fall voltage) is defined by the ionization potential of the metal vapor. It has been shown later that the main ionization processes are due to thermal electrons in the near-cathode plasma volume, and that the main part of the cathode voltage falls across the plasma and has an ohmic nature. It has been noted that in the vicinity of an emission center in a cathode spot the potential difference between the plasma and the cathode should correspond to the floating potential of the plasma, i.e., to the condition that the current onto the cathode is absent. In this paper this condition is proposed to be considered as the main criterion defining the value of the cathode fall voltage as well as the arc fall voltage as a whole