The stabilizing effect of a conducting boundary on the diocotron instability of nonneutral electron flow

The effect of the conducting boundary on the temporal evolution of the diocotron instability of a planar and a cylindrical electron flow in a uniform magnetic field has been investigated by using two-dimensional particle-in-cell (PIC) simulations for various boundary-wall locations. The growth rates measured in the PIC simulations match well those calculated by using analytic linear theories. The approach of conducting boundaries to the electron flow was observed not only to reduce the growth rate of the diocotron instability but also to change the mode structure. The nonlinear behaviors of the instability lead to a phase-locking configuration to generate vortices.