Observation of the metallic vapor from a plasma focus

Although many scientists suggested that the ionized metallic vapor produced in plasma focus plays a significant role in the X-ray emission, they did not give a visual image of the metallic vapor. In this paper the evolution of plasma sheath above the anode was recorded with a laser differential interferometer and the metallic vapor produced on the target surface by bombardment of an intense electron beam was observed for the first time. The results can help understanding of the physical process of the X-ray emission from plasma focus.