Abstract :
Field emission from liquid metal surfaces occurs with different mechanisms such as from liquid metal vapor arc cathode spots and liquid metal electron sources. At rather bulk liquid metal coverages, in both cases the emission performance likewise is affected by hydrodynamic and electrohydrodynamic effects, respectively. Reducing the liquid metal coverage to a relatively thin liquid metal film, the field-induced microstructure, as well as the intrinsic microstructure of the liquid metal film on a solid substrate dominates, and new emission modes appear. Representative examples for that are the film emission mode of liquid metal film cathodes (LMFC) and the stationary emission mode of microstructured liquid metal electron sources (MILMES). Both field emission from a cathode spot as well as from a field emitter in vacuum is examined in the scope of the dynamic field (DF) emission model which has been adapted for this purpose, considering especially emission stability. Finally, experimental results obtained with a mercury film cathode, and different types of cesium liquid metal electron sources are analyzed and compared with theoretical aspects of the DF emission model.
