Reaearch on Electron Beam Focus Properties in Plasma

The equation of electron trajectory in drifting tube filled with plasma is given in this paper.The space is divided into two areas (α and β),the equation is solved and focus properties are studied and some parameters affecting the focus properties are discussed carefully.The study shows that after the tube is filled with plasma,the beam is focused obviously,and the design of drifting tube and adjustment of beam transmission pattern are more convenient.