On the nature of secondary current in plasma formed in zone of electron beam action during welding

A physical model of processes of secondary current appearance in plasma formed in the electron-beam welding is suggested. Thermionic emission from a region of collision of an electron beam and metal in penetration channel is responsible for appearing secondary current. A consideration of possible mechanisms of secondary current oscillations demonstrated that these oscillations affected the process of electron beam-metal interaction during welding and parameters of on electron beam and metal are connected with characteristics of penetration channel