Explosive electron emission from liquid-metal cathodes

Since the discovery of explosive electron emission 40 years ago, the overwhelming majority of investigations of this phenomenon have been performed with solid-state metal cathodes. At the same time, liquid-metal pool point cathodes, by virtue of some favorable properties, allow one to perform more reliable physical experiments. The peculiarities of liquid-metal cathodes are related to the features of the formation of an emitting protrusion under the action of a strong electric field. The high stability of this process in space and in time for a cathode repetitively operating under the conditions of pure high vacuum and moderate voltages (10-30 kV) ensures highly reliable experimental data. Liquid-metal cathodes may be of great practical importance. This paper is a review of the studies of the explosive electron emission from liquid-metal point cathodes.