Recent Developments in Scandia-Doped Dispenser Cathodes

We measured SDDCs emission property and made comparison with impregnated scandate (I-Sc). A reasonable explanation on abnormal Schottky effect of SDDCs is given. The authors proposed a "semiconductor-monolayer superposition" model to explain emission mechanism of all kinds of thermionic cathodes, including oxide cathodes, M-type cathodes and scandate cathodes. Finally, from the view of engineering application, some improvement ideas and suggestions to future work of SDDCs are given