Interactions of multipactor and RF circuit

Summary form only given. Multipactor is an important resonant discharge phenomenon in microwave cavities, windows, satellite RF payloads, and accelerator structures. We use a simple model to analyze the interaction of multipactor with an RF circuit and obtain the following results. Multipactor current may, transiently, reach a high level, especially in a high Q cavity. It saturates at a much lower level in the steady state, primarily by its loading of the cavity; the space charge effects play a relatively minor role. At saturation, the electron impact energy equals the lowest value that gives unity in the secondary yield curve. There is a new phase focusing mechanism, whereby the leading edge of the multipactor discharge grows at the expense of the trailing edge, in spite of the mutual repulsion among the electrons. This phase focusing mechanism may shape the steady state multipactor in the form of a very tight bunch of electrons. A synthesis of the above results allows us to predict the conditions under which steady state multipactor will occur, once the material of the multipactoring surface is specified.