Multipactor suppression in amplitude modulated radio frequency fields

An analytical and numerical investigation is made of the multipactor phenom enon in a simple one-dimensional metallic gap exposed to a homogeneous rf f ield consisting of two carrier waves with close but separated frequencies. It is shown that in contrast to the monochromatic case (i.e., single carrie r operation), the time varying envelope resulting from the beating of the t wo carrier waves leads to a suppression of multipactor breakdown, if approp riate combinations of carrier amplitudes and frequency separation are chose n. Furthermore, this combination depends neither on gap width nor on freque ncy range. Based on these results it is possible to draw the tentative conc lusion that the regime of multicarrier operation is very promising from the point of view of avoiding breakdown. This is particularly so in systems of complicated geometry where single carrier operation may lead to multipacto r breakdown for any high level of rf power. (C) 2001 American Institute of Physics.