Interaction of a nonrelativistic electron beam with a semiconductor cylinder in an external magnetic field

The paper presents a theoretical study of electrostatic oscillations in a cylindrical system, which represents an electron beam surrounded by a semiconductor of finite thickness, adjacent to a dielectric or a perfectly conducting metal. The system is placed in a finite axial magnetic field. The results of the analysis show that space charge waves (the drift waves) and cyclotron waves could be unstable. It is also shown that, as the external magnetic field or the collision frequency of electrons increases the growth rates of the instabilities decrease.