Suppressing and initiation of multipactor discharge on a dielectric by an external dc bias

The results of studying experimentally the influence of an external dc electric field on the multipactor threshold on the surface of a dielectric (quartz) are presented. In the experiments, a high-Q-factor microwave resonator was excited at the TE012 mode in the 3-cm wavelength band. The dependence of the breakdown threshold on the value and direction of the electrostatic field is determined. It is found that the external dc field repulsing the electrons from the dielectric surface increases the threshold significantly, whereas the field attracting the electrons decreases it. It is shown that one can manage the multipactor efficiently, namely suppress or initiate it, by changing the direction and intensity of the dc field.