In this paper

electron beam physics

equilibrium of plasma in Tokamak under electron injection and physical problems involved in the electron injector were analytically studied. The result indicates that the electron beam will be stable when intensity of added electrical field is larger than that of beam’s electrical field. For maintaining the equilibrium of plasma in Tokamak it is better to set the intensity of added field as low as possible. The working temperature of cathode between 8001000K will meet the requirement for experiment on HT--6M Tokamak. By using some insulation measures the injector should be workable and safe under a voltage of 25kV.