Multipactor experiment on a dielectric surface

A novel experiment to investigate single-surface multipactor on a dielectri c surface was developed and tested. The compact apparatus consists of a sma ll brass microwave cavity in a high vacuum system. The cavity is similar to 15 cm in length with an outer diameter of similar to 10 cm. A pulsed varia ble frequency microwave source at similar to2.4 GHz, 2 kW peak excites the TE111 mode with a strong electric field parallel to a dielectric plate (sim ilar to0.2 cm thickness) that is inserted at midlength of the cavity. The m icrowave pulses are monitored by calibrated microwave diodes. An electron p robe measures electron current and provides temporal measurements of the mu ltipactor electron current with respect to the microwave pulses. Phosphor o n the dielectric surface is used to detect multipactor electrons by photoem ission. The motivation of this experiment is to test recent theoretical cal culations of single-surface multipactor on a dielectric. (C) 2001 American Institute of Physics.