Mitigation Of The Diocotron Instability In A Hollow Electron Beam Using Rotating Magnetic Fields

A two-dimensional cylindrical particle-in-cell (PIC) simulation is utilized to understand the tendency of the diocotron instability in a hollow electron beam and to mitigate it. We have conducted a parametric study with the variation of the number density of electrons, the cathode voltage, the system size, and the amplitude and the frequency of periodic dipole magnets. Two orthogonal arrays of periodic dipole magnets make rotating magnetic fields which perturb the shear flow of the electron beam by the ExB drift motion. Finally, the conditions for the mitigation of the diocotron instability are investigated. This study is based on our previous study on the control of the diocotron instability of a hollow electron beam with periodic dipole magnets [1].