Elektronenkanone

Known chemical vapour deposition electron guns, preferably axial guns, are not suitable for deposition processes in low vacuums down to several 100 Pa at high power density. For certain deposition tasks, however, beam capacities of about 10 kW are required at a power density of up to > 10->5 W/cm->2. According to the invention, a separately evacuatable beam guidance unit is arranged on the focusing lens in the beam direction on a largely known electron gun. Said beam guidance unit is connected to an electrically insulated mouthpiece bearing ground potential, having a central opening and facing the working chamber subjected to a higher pressure. The electron gun can be used for the chemical vapour deposition of various materials in low vacuums.