Abstract: A grounded metallic shield which comprises an electrode enclosing the filament leads and emitters of an e-Gun in a high vacuum chamber of the type used in melting and casting metals and other materials and evaporation sources. The shield is spaced from the filament leads and emitters a distance in the order of the electron mean free path for the pressure uses within the high vacuum chamber. The structure and method of use thereof suppresses or eliminates arc-downs or glow discharges.

Abstract: A crucible contains a metal to be evaporated by heating from an electron beam source wherein the path of the electrons is controlled by a horizontal transverse magnetic field over the source and crucible. A number of small individual magnets are arranged horizontally along opposite sides of the crucible parallel to the beam path. The inner end of each magnet is in the closest position possible to deliver its flux lines to the magnetic field area. By varying the positions of the magnets, the field generated may be controlled in the desired manner.

Abstract: A plurality of electron gun assemblies having transverse magnetic fields to focus an electron beam into a crucible to vaporize a material may be closely placed in parallel by inserting between the assemblies a thin magnetic fence magnetized across its surfaces. The polarity of a fence surface is the same as the polarity of the adjacent sidewall magnet forming the transverse field so that the opposition will prevent magnetic flux from passing between adjacent assemblies and a resulting distortion and defocusing of the electron beam.

Abstract: A crucible contains a metal to be evaporated by heating from an electron beam source wherein the path of the electrons is controlled by a horizontal transverse magnetic field over the source and crucible. A number of small individual magnets are arranged vertically along opposite sides of the crucible parallel to the beam path. One end of each such magnet is in the closest position possible to deliver its flux lines to the magnetic field area. The magnets maybe permanent or electro- or a combination thereof. By varying the positions of the magnets, the field generated may be controlled in the desired manner.

Abstract: A grounded metallic shield which comprises an electrode enclosing the filament leads and emitters of an e-Gun in a high vacuum chamber of the type used in melting and casting metals and other materials and evaporation sources. The shield is spaced from the filament leads and emitters a distance in the order of the electron mean free path for the pressure uses within the high vacuum chamber. The structure and method of use thereof suppresses or eliminates arc-downs or glow discharges.