Abstract: An electron gun that prevents undesirable arcing by providing an improved electrostatic field that generates a confined electron stream, an improved magnetic field that directs the confined electron stream to a crucible with minimal divergence, and an improved insulation on high voltage leads. The improved electrostatic field is provided by a cathode plate disposed adjacent to a filament and forming a cathode window aligned to the filament. An anode plate disposed adjacent to the cathode plate forms an anode window aligned to the cathode window. The cathode plate and anode plate form an electrostatic field and lensing effect that directs electrons emitted from the filament through the cathode and anode windows with minimal divergence. The improved magnetic field is provided by a magnet having a pair of poles, a pair of extension plates each extending from the magnet poles, and a plurality of extension members that extend from the extension plates toward the path of the electron stream.

Abstract: An electron beam gun with liquid cooled rotatable crucible is disclosed including a metallic bellows connected to the housing for the rotatable crucible at a 90.degree. angle and the bellows contractible to a minimum length that is a straight line between the axis of the housing and the remote end of the bellows with the bellows permitting rotation about the housing axis as the crucible is rotated to place different pockets in target position of the E-gun.

Abstract: A circulating coolant reservoir is used to uniformly cool a removable crucible in an electron beam gun assembly for vaporizing material to be deposited at another location. The outer surface of the crucible is substantially immersed in the coolant reservoir and coolant is circulated around the outer surface from diametrically opposed inlet and outlet lines whose axes are tangent to the reservoir walls and with an upwardly spiraling groove in the crucible outer surface.