Integrated cathode testing

Summary form only given. Comprehensive evaluation of dispenser-type cathodes during development and optimization programs requires a wide range of in-situ diagnostics tests. These tests include Auger surface analysis, cathode activity, cathode current stability, barium evaporation rate, and robustness to poisons. A unique, sophisticated experimental chamber has been developed at EDD for the purpose of evaluating M-cathodes. The apparatus consists of three interconnected vacuum chambers: the insertion chamber, the life test chamber and the specimen test chamber. The insertion chamber can be vented to atmospheric pressure without disturbing either the life test or specimen test chamber. Once loaded, the gate valve to the specimen test chamber can be opened and the cathodes can be transported to a holding platform in the specimen test chamber. This chamber is equipped with an electron gun, Auger spectrometer, secondary electron detector, an ion gun, a bare filament quadrupole mass spectrometer and an anode grid. This permits complete testing of the surface conditions and emission properties in the main chamber.