Numerical study of various scenarios for the formation of atmospheric pressure DC discharge characteristics in argon: from glow to arc discharge

In this work, on the basis of a unified model from the point of view of describing the gas discharge gap and electrodes for 2D geometry, numerical calculations were carried out to study various modes of direct current discharges in argon at atmospheric pressure. The influence of the cooling conditions of the electrodes on the current–voltage characteristic of the discharge is shown: the transition from normal glow to arc discharge with the formation of an abnormal glow mode and without it. It is shown that, depending on the cooling conditions of the electrodes, two forms of arc discharge can be obtained: with a diffuse or contracted current spot. In the low-current mode, current and voltage oscillations were obtained during the transition from the Townsend to the normal glow discharge.