Abstract: An electron beam memory system comprises a substrate mounted for rotation and supporting an information storage medium. Means are provided for rotating the substrate. An electron gun comprises a field emission cathode having an emitting tip, anode means, and means for developing and applying between the tip and the anode means a predetermined accelerating potential for forming a high brightness electron source at the tip and for causing an electron beam to be formed through the anode means. The gun includes focus lens means for receiving the beam and for forming a very small yet intense electron beam probe at a predetermined first focal distance therefrom.

Abstract: A rapid random accessed electron beam memory system comprises a disc mounted for rotation and supporting an information storage medium. An electron gun is mounted for movement across the disc. The gun has ultra-compactness and extremely low mass, yet is capable of developing a finely focused electron beam probe at high beam current densities. The gun comprises a low-mass field emission cathode, the cathode having an emitting tip and being adapted to receive a predetermined electrical potential to form a high brightness electron source at the tip. An electrostatic focus lens forms a real image of the electron source in the vicinity of the storage medium. The lens comprises a first electrode adapted to receive a predetermined second electrical potential which is positive relative to the potential on the tip and has a value effective to extract electrons from the tip. The electrode defines a relatively small aperture for deforming the diameter of an electron beam which is formed.

Abstract: An axially compact field emission cathode assembly for use in an electron beam device comprises a field emission tip, an electriclly conductive filament for mechanically supporting said tip and for receiving and conducting to said tip a predetermined electrical potential for exciting said filament to cause electron emission from said tip. Filament support means supports the filament with the tip positioned on an electron beam axis within said device. The cathode assembly is characterized by the filament being supported by said filament support means to extend transversely to the electron beam axis, whereby to reduce the axial length of the device.

Abstract: An ultra-compact electrostatic electron gun includes integrated beam-modifying means for use in electron beam memory systems, electron microscopes, electron lithographic devices and the like. The gun is illustrated as comprising means forming a point source of electrons and means receiving electrons from the point source for defining an electron beam. Electrostatic lens means receives the beam and forms a beam focus. An integrated magnetic field-generating means establishes a field of magnetic flux through the electrostatic lens for modifying the position, cross-sectional shape or other characteristic of the beam.