Effects of an external magnetic field, and of oblique radio-frequency electric fields on multipactor discharge on a dielectric

This paper analyzes, separately, the effects of an external magnetic field, the rf magnetic field, and of an oblique rf electric field, on multipactor discharge on a dielectric. Using Monte Carlo simulation, we obtain the susceptibility diagram in terms of the magnetic field, the rf electric field, and the dc charging field for various dielectric materials. We find that a magnetic field parallel to either the rf electric field or the dc electric field does not qualitatively change the susceptibility diagram. However, an external magnetic field perpendicular to both the rf electric field and the dc electric field can significantly affect the susceptibility diagram. Thus oriented magnetic fields lower the upper susceptibility bound when the magnetic field strength is approximately equal to $Bres[T]=0.036f(GHz),$ where f is the rf frequency. Both the lower and upper susceptibility boundary may be raised significantly by a large external magnetic field, $B≫Bres.$ Susceptibility to single surface multipactor is greatest when the rf electric field is nearly parallel to the dielectric, but is dramatically decreased for angles of obliqueness greater than approximately 5°–10°. The rf magnetic field does not affect the lower boundary, but may extend the upper boundary greatly.