Abstract: A cap can comprise an aperture, and an attenuator may block the aperture during at least one point in time. In one embodiment, the attenuator can include a cover that may be displaced by a spring. In another embodiment, such as an electron gun, may comprise a support cap with an aperture, a displaceable cover that may cover the aperture, and a spring. A material attached to the spring and acting as a fuse may release the spring and expose the aperture after an electrical current blows the “fuse”. In yet another embodiment, a method for using a tube may comprise evacuating the tube while a cover covers an aperture in the support cap of a electron gun that is at least partially in the tube and moving the cover to expose the aperture after the tube is sealed.

Abstract: An electron source includes a vacuum chamber within which a vacuum is maintained by a vacuum pump. An insulated receptacle is mounted within the vacuum chamber and has a receptacle mounting flange. The receptacle mounting flange is used to establish a coordinate system having an electron beam axis and a lateral plane, wherein the lateral plane is transverse to the electron beam axis. An adapter is mounted to the receptacle and is adjustable in five degrees of freedom with respect to the coordinate system. A cathode and focus electrode are adjustable in at least four degrees of freedom and are pre-aligned with respect to one another prior to being installed on the adapter. An anode is mounted in the vacuum chamber and is aligned at a predetermined distance from the cathode with respect to the coordinate system.

Abstract: A mechanically tunable magnetron injection gun (MIG) provides an annular, relativistic beam of electrons for injection into an axially aligned magnetic field of a gyrotron-class device. The electron emitter encircles a center electrode. Turning a knob adjusts the center electrode's axial position relative to the rest of the cathode. The adjustable center electrode provides an effective means for local field adjustment. The center electrode is located in a particularly sensitive electric field region and adjusts the electric field so as to tune the electron beam from the inside out. Adjusting the center electrode position while the device is in operation is a means for providing mechanical tunability (with respect to beam quality and transverse-to-axial velocity ratio) for the MIG.

Abstract: A cathode ray tube includes a panel having a fluorescent screen formed on an inner surface thereof, a stem, and a neck between the panel and the stem. An electron gun is supported by a supporting structure in coaxial alignment with the neck. The electron gun has a focusing electrode which includes a first cylinder and a second cylinder having a larger diameter than the first diameter. The first cylinder has a first opening which opens toward the stem and the second cylinder has a second opening which opens toward the panel. A conductive layer is deposited on the inner surface of the cathode ray tube and receives a high voltage. An annular holder is mounted to the supporting structure so that the annular holder surrounds the first cylinder in coaxial alignment with the focusing electrode. The annular holder is a first predetermined radial distance away from the first cylinder and a second predetermined axial distance from second cylinders.

Abstract: An electron gun for producing a beam of electrons has an elongated, linear thermionic cathode and a focusing electrode. The opposite ends of the cathode are engaged by adjustable holders which enable the spatial separation between the cathode and focusing electrode to be easily varied. The focusing electrode is electrically isolated from the cathode whereby fine tuning of the electron beam may be accomplished by varying the potential difference between the focusing electrode and cathode.

Abstract: An electron beam apparatus comprises an electron source with an electron emitter in the form of a wire, suitably of metal, which slides on two supports. The two supports are constructed and spaced apart at such a distance (not more than 1 millimeter) that for the wire portion between the supports, a thermal equilibrium is achieved which is optimum for high electron emission from a small area of the wire. The wire can be heated to a temperature just below its melting point and is transported across the support under a low tensile stress.

Abstract: Apparatus for compensating the injurious increase of the cathode current occurring during the initial operation period of a travelling-wave tube when, during successive warming-up, the grid first approaches the cathode and then assumes the nominal distance therefrom. The apparatus includes a distance control device measuring the deviation between the actual grid-cathode distance and the nominal distance and generating a control signal proportional to the deviation for reducing the value of the grid voltage.

Abstract: Disclosed is a directly heated cathode assembly for a cathode ray tube electron gun, comprisingfirst and second conductive support members disposed to face each other via an insulating base plate,a ribbon filament stretched between the first and second conductive support members such that the width direction thereof is parallel with the axis of the electron gun,a cathode consisting of a metal substrate covered with an electron emissive coating and a support portion integral with or fixed to the metal substrate, the coating layer extending in a direction perpendicular to the axis of the electron gun and the cathode being mounted to the central portion of the filament, andat least one spring member whose free end resiliently abuts against the filament in a direction perpendicular to a plane including the axis of the electron gun.

Abstract: An electron gun asembly comprising direct heated cathodes each having an electron emitting member fixed on a filament which is stretched between a pair of support means disposed face to face with each other on a substrate and a plurality of grid electrodes containing first grids, said cathodes and grid electrodes being secured with predetermined distance with one another by insulative support rods. Each of the cathodes has a means adjusting the spacing between the first grid electrode and the electron emitting member.

Abstract: A hollow, cylindrical, rotating anode, X-ray tube for tomodensitometers.This tube contains a bell-shaped, hollow, cylindrical anode functioning by transmission, which is swept on its inner surface by an electron beam and produces in cooperation with a collimation device having several openings a series of fine X-ray beams, which are roughly parallel and coplanar, the number of these beams being equal to the number of openings in the collimation device. Such a tube makes very fast tomography possible.

Abstract: An electron gun apparatus comprises a cathode subassembly which is movably mounted relative to a fixedly mounted and registered grid/anode subassembly to permit mechanical adjustment of the cathode with respect to the grid/anode subassembly. An evacuated chamber, including resilient bellows interconnecting the movably mounted cathode assembly to the fixedly mounted grid/anode subassembly for permitting the mechanical adjustment, houses the cathode and the grid/anode subassemblies. Means are provided for electrical energization of the cathode, the grid, and the anode. According to a further feature of the invention, the cathode comprises a line filament, and the grid and the anode are slotted for providing an elongated line image.

Abstract: A device for generating a high level electron current pulse includes a housing whose interior can be evacuated from outside the housing, a cathode electrode located in the housing and arranged to be connected to a high voltage generator, an anode electrode disposed in the housing in facing relation to the cathode electrode, the anode electrode having an opening aligned with the electron emission portion of the cathode electrode and being provided with a grid which covers this opening and which presents a high electron transmission level, the grid defining a plane with one face of the anode electrode, and the walls of the housing defining an annular space filled with a solution whose resistivity is a function of its concentration to give these walls a variable electrical resistance which can be adjusted to match the impedance of the cathode electrode - anode electrode system to that of the high voltage generator.

Abstract: An electron beam generator with a linear cathode which has at least one end clamped to enable the cathode to move longitudinally. A beam forming electrode is at the same potential as the cathode and has an exit opening for the electron beam. The beam-forming electrode is provided with connection means to supply beam and heater voltage to the cathode. The clamps used to clamp the cathode, are connection contacts for the ends of the cathode and are outside of the contact points in the emission area of the cathode.