A design for a multipactor experiment on a dielectric surface

Summary form only given, as follows. A novel experiment for single surface multipactor on a dielectric surface is underway at the University of Michigan. The simulations that lead to the design of the experiment will be presented along with some preliminary calculations. The emphasis is on the susceptibility of multipactor discharge and its subsequent loading of the cavity modes. The experiment consists of a small brass microwave cavity in a high vacuum system. The dimensions of the cavity are /spl sim/15 cm in length with an outer diameter of /spl sim/10 cm. A pulsed microwave source at /spl sim/2.5 GHz delivers up to 5 kW peak power to the cavity. The microwaves excite the TE111 mode so that there is a strong electric field parallel to the dielectric surface. The Hewlett Packard HFSS code is used to model the fields and helped determine the optimal positioning of the dielectric and verified that the TE111 mode resonated with only a slight change in resonant frequency. The power supply is frequency adjustable. Micro-coax will be used to probe the fields and a collector probe and photodiode will be used to identify the multipactor.