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. The magnetic field-generating means is adapted to receive static or dynamic control signals and is characterized by comprising means positioned axially coincident with and surrounding the electrostatic lens to effectively immerse substantially the entire lens in the beam-modifying magnetic field, whereby due to the axial coincidence of the magnetic field-generating means with the lens, a characteristic of the electron beam may be modified without the magnetic field-generating adding significantly, if at all, to the axial length of the gun.
Abstract:
A device for recording or displaying images or for electron lithographic or electron microscopic uses, comprising in an evacuated envelope (1) a target (7) on which at least one electron beam (6) is focussed. This beam is generated by means of a semiconductor device (10) which comprises an electrically insulating layer (42) having an aperture (38) through which the beam passes. The layer carries at least four beam-forming electrodes (43 through 50) which are situated at regular intervals around the aperture (38). Each of the electrodes has such a potential that an n-pole field or a combination of n-pole fields is generated, where n is an even integer from 4 through 16. A suitable choice of the n-pole field will make it possible to impart substantially any desired shape to the beam (6) and thus the focus on the target.
Abstract:
A high beam power electron gun of the axial type, particularly useful in large-scale vacuum metallurgy plants for melting, vaporizing and heat treating. The electron gun is controllable over its entire power range, i.e., from 10% to 100% of its nominal power, while the focal length of its beam guidance lens is maintained unchanged. This lens is downstream of a cathode, a focusing electrode and a movable anode, and is provided on its upstream side with a pole shoe to which the anode is fastened and which, together with the anode, is movable as a single unit in the axial direction for controlling the power.
Abstract:
A beam generating system for electron tubes, particularly travelling wave tubes, is formed of a beam shaping electrode and a dispenser cathode supported therein having an emission disk at its end face. A positional change of the dispenser cathode in the beam shaping electrode at different ambient temperatures is suppressed with the beam generating system, and thus a beam defocussing is avoided. According to the invention, the dispenser cathode is directly connected to the beam shaping electron and is connected below the emission disk by means of a radial cathode support. The beam generating system of this type is particularly employed in travelling wave tubes.
Abstract:
An electron beam gun comprising a beam generator (4), an acceleration chamber (7) and a beam-guide chamber (10). The beam-guide chamber is formed by a jacket tube (19) and a beam-guide tube (18), which extends to the work chamber (1) and is surrounded by a focusing lens (15) and a deflecting device (17). For the purpose of readily adapting the equipment to suit various objective distances and for making cleaning and inspection easier, the jacket tube (19) takes the form of a hollow cylinder and is secured between two connecting flanges (20, 21) in a manner whereby it can be replaced. The upper connecting flange (20) carries a centering flange (28), on which the beam-guide tube is suspended, a shut-off valve (11) being optionally provided between the centering flange and the beam-guide tube. The lower connecting flange (21) surrounds a vacuum-connecting flange (34) in which is fitted the lower end of the beam-guide tube (18). Thus, when the beam generator (4) is removed, the beam-guide tube (18) can be extracted from the focusing lens (15) and from the deflector unit (17) through the acceleration chamber (7), together with the centering flange (28). The boundary between the vacuum and the atmosphere lies in the zone of the beam-guide tube (18) and of its various sealing elements.
Abstract:
A preferably fully impregnated dispenser cathode member or the like forming part of an electron tube, electron beam generator or the like is initially heated by any suitable means to a temperature sufficient for low level electron emission from its rear surface. A hot plate member of preferably equal size is disposed behind the cathode and can either be part of or the means for initially heating the cathode member or it can be heated with the cathode member to the aforementioned cathode member's rear surface low level emission temperature. A sustainer voltage is applied between the cathode member and the hot plate member sufficient to draw a current comprising electron flow from the cathode member to the hot plate member across the space separating them. This current flow or back electron beam results in heating of the hot plate member to a temperature sufficient to raise the closely spaced cathode member to, and then maintain it at, the desired emission temperature and simultaneously allow timely termination of the initial heating process since it is needed only initially.
Abstract:
The present invention is an improvement in an electron gun assembly. Such a gun assembly includes a plurality of indirectly heated cathode assemblies and at least two spaced successive electrodes having aligned apertures therein for passage of a plurality of electron beams. The cathode assemblies include a plurality of cathode heaters which are attached to at least two electrically insulating support rods by a plurality of heater bead straps. Each of the heater bead straps includes a main body portion having a distal end and a proximal end. The proximal end has a bifurcated portion comprising a pair of closely spaced apart grasping members for embedment into one of the insulating support rods. At least one member of the pair of grasping members is angulated with respect to the main body portion to increase the retention of the heater bead straps to the insulating support rods.
Abstract:
The invention is directed to a picture tube comprising an electron gun installed within an evacuated envelope which receives various potentials supplied from a potential source. The electron gun comprises a cathode for generating an electron beam and a plurality of successively arranged electrodes for focusing and accelerating the electron beam. One or more supporting rod secures the electrodes. Each of the supporting rods comprises an insulator portion and a glass resistance portion. The glass resistance portion acts as a solid bulk resistor and secures in direct connection with at least one electrode of the electron gun. Consequently, potentials from the potential source are applied to certain electrodes through the glass resistance body. In a further embodiment the entire supporting rod consists of a homogeneous glass resistance body.
Abstract:
An achromatic magnetic deflection device for deflecting by an angle .phi. between .pi. and 2.pi. a beam of charged accelerated particles having different momentum. This device comprises an electromagnet provided with pole pieces delimiting three contiguous sectors, the whole of these sectors, having an axis of symmetry XX, presenting flat input E and output S faces and common faces F.sub.1 and F.sub.2 in an arc of a circle, the position, the radius of curvature of these faces F.sub.1, F.sub.2 as well as the value of the magnetic induction in the sectors being chosen so that the different paths are substantially orthogonal both to faces F.sub.1, F.sub.2 and to axis XX.
Abstract:
In a color television display tube the electron gun system constructed from three electron guns comprises a first group of corresponding electrodes and a second group of corresponding electrodes to be operated at a higher electrical potential than the first group. The electrodes in each group are positioned relative to each other by means of metal braces connected thereto. The ends of the braces are secured to insulating support rods. At least one group of corresponding electrodes is interconnected by means of one or more conductive contact springs surrounding the support rods and touching the surface of each electrode or of the brace connected thereto.