Effects of anode materials on explosive field emission diode performance

Summary form only given. Explosive field emission cathodes have been the cathode of necessity for most classes of gigawatt microwave tubes. These emitters have the advantages of generating high current densities, ease of use and the ability to operate in poor vacuums. However, these cathodes do have the disadvantage of short lifetime and large amounts of out-gassing, both of which adversely affect tube performance. In this talk, we discuss a series of experiments in which we characterize the effects of the anode on the diode performance. In particular, we show that the anode material can have a great impact on the out-gassing as well the total diode current. We also discuss the anode plasmas which are generated during operation of the diode.