Vacuum evaporation experiences with a ring-type electron beam gun

The ring-type electron beam gun is a relatively simple device, working on the principle of a hot cathode, high vacuum diode. In vacuum evaporation applications, the presence within the gun of the material to be evaporated and its vapour can lead to anomalous performance in several ways. An understanding of these anomalies and their consequences is helpful in achieving more effective operation of the ring gun as a vacuum evaporation source.