A theoretical model for suppression effect of single-surface multipactor on dielectric by external DC magnetic field

This paper proposes a theoretical model for the single-surface multipactor on a dielectric. We consider the combined effects of the normal cumulative electric field, the normal and tangential radio frequency (RF) electric fields, as well as the tangential external direct current (DC) magnetic field and study the suppression effect of the tangential external DC magnetic field on the resonant multipactor. Kinetic properties of the electron and the resonant multipactor condition with no tangential external DC magnetic field are derived by analytical calculations. The flight time of the electron is analyzed profoundly by considering different values of the electron's initial energy, the amplitude ratio between the normal cumulative electric field and the normal RF electric field, and the tangential external DC magnetic field. Our results demonstrate that the tangential external DC magnetic field can decrease the flight time, and hence, the resonant multipactor can be suppressed or mitigated effectively by the tangential external DC magnetic field. The flight time of the electron shows a decreasing trend as the electron's initial energy increases, and the amplitude ratio between the normal cumulative electric field and the normal RF electric field decreases. The suppression effect of the tangential external DC magnetic field on the resonant multipactor can be much stronger when the amplitude ratio between the normal cumulative electric field and the normal RF electric field becomes larger. The resonant multipactor suppressing is also relevant to the amplitude ratio and the initial phase difference between the tangential and normal RF electric fields.