his study is related to the fundamental aspects of the arc-cathode interactions in atmospheric and higher-pressure arc systems. The primary objective of this paper is to demonstrate that, evm though the arc attachment on bdh refr;zctory and wn-refractory cathcdes appear substantially mereat, they follow the same physics and therefore the same model can be applied to describe both situations. Indeed, it is shown that the two situations are actually representing the two extremes of a unique descriptian; the self-suStaintng opemtion of an arc discharge on a reffadory (hot) cathode is achieved without the need of vaporization of the cathode surface while for non-refhctory (cold) cathodes, a strong vaporization resulbng in a pressure build up in the cathode region is necessary for self-whined arc operation.