Abstract: A grid-controlled electron tube is constructed with a common anode and an array of individual cathode-grid modules. The simple modules can be built with greater accuracy than large, complex electrodes. The modules can be individually tested before final assembly, and can be individually replaced in case of a failure during construction or later operation. In a preferred embodiment, the cathode is a cylindrical filament surrounded by a coaxial grid, each grid turn being mounted to a common support on the side opposite the anode. In a tetrode embodiment, additional focusing bars at the sides of the grid direct electrons into beams which pass between large screen-grid wires.

Abstract: A Microwave reflection amplifier having improved gain, bandwidth and noise characteristics, uses two negative-resistance diodes, such as Gunn-effect diodes, connected in series across the terminals. The diodes are series resonated by inductance in their leads. The gain and bandwidth are higher than in amplifiers using a single diode. A shunt-resonant circuit is connected across one diode to improve the gain-bandwidth. A second shunt-resonant circuit may be connected across the terminals. At very high frequencies, the amplifier uses strip-line or microstrip circuitry and the shunt resonators are half-wavelength transmission lines.

Abstract: A solar energy converter uses gallium arsenide photovoltaic cells to convert light to direct current. Optical concentrators reduce the needed area of cells. Gallium arsenide retains high conversion efficiency up to several hundred degrees, so the waste heat may be used to produce mechanical power in a Rankine cycle engine.

Abstract: Intensifier tubes for x-rays or low-light levels form an image of photoelectrons which is focused on a fluorescent viewing screen. Stray magnetic fields, including the earth's field, bend the electron trajectories and distort the image. Magnetic shielding has been used around the tube, leaving the image-receiving end open. Magnetic field leaking through the open end is reduced by extending the end of the shield around the image-receiving aperture inward and forward of the edge of the tube.

Abstract: Klystron cavities having linearly movable tuning elements are tuned simultaneously by a single master control which tilts a tuner drive platform. The motion is transmitted to individual cavity tuners by drive elements on the platform at selectable distances from its tilting axis so that the tuning rate of each cavity may be selected for proper tracking with the others. Individual position adjustments of each tuner allow exact setting at a selected reference frequency. The combination of the two sets of independent adjustments permits the resonant frequencies and tuning rates to be independently set at a given reference frequency, or alternately the resonant frequencies may be aligned at two different reference frequencies. Thus the cavity frequencies are made to track during continuous tuning over a wide range.

Abstract: A permanent magnet structure particularly beneficial for generating the interaction field in coaxial, crossed field electron tubes is designed such that the normal iron flux return path is not required. Substantial reduction in weight results. A further benefit is that a magnetron interaction structure including the magnets may be built as a unit replaceable in the field in a stabilizing cavity structure. Since the cavity structure contains no iron, the magnets are not demagnetized in the replacement process and there are no mechanical mounting problems caused by magnetic forces.

Abstract: The electron gun includes a spherically concave cathode emitter with a pair of axially spaced spherically concave focus and control grids closely spaced overlaying the cathode emitter for controlling the beam current. The grids are supported from a common thermally conductive tubular grid support structure via the intermediary of first and second annular members one of which is a thermally conductive insulator. One or more of the grids are serrated about their peripheries to define a plurality of radially directed fingers bonded to the end of a respective annular grid support member. In an alternative embodiment, the end of the annular grid support member, as bonded to the serrated grid, is castellated to accommodate differences in thermal expansion between the grid and the annular grid support member.

Abstract: A lateral semiconductive device, such as a Gunn device or Impatt diode, is fabricated by depositing a barrier layer of beryllia over an epitaxial grown layer of N- type semiconductive material on an N+ type semiconductive wafer. The wafer is then thinned down, as by grinding and polishing. Electrode material is then deposited overlaying the N+ wafer layer for making ohmic contact thereto. The electrode material is etched to define at least a pair of laterally spaced electrodes, each making electrical connection to the epitaxial N- layer via the intervening layer of N+ wafer material. In the case of a Gunn device, the insulative barrier layer provides electrical insulation and prevents undesired leakage of current. In addition, it serves as a barrier to prevent metallic contact materials from diffusing into the epitaxial N- layer. Further, it serves as a heat sink between the active device and its mount.

Abstract: An ultra wide band traveling wave tube amplifier is disclosed. The amplifier employs a helix derived slow wave circuit arranged for electromagnetic interaction with a beam of electrons passable axially through the helix circuit. Signals to be amplified within the passband of the circuit interact with the electron stream to produce an amplified output signal which is extracted from the helix and coupled to a suitable utilization device. The bandwidth of the traveling wave tube amplifier is substantially increased by the provision of a conductive circuit loading structure disposed surrounding the helix circuit and extending for at least half of its length and preferably for substantially its entire length.

Abstract: A grid-controlled electron source comprises an apertured grid spaced in front of a thermionic cathode. Areas of the cathode directly behind the grid conductors are made non-emissive by a bonded surface layer of non-emissive material such as zirconium. On porous metal cathodes impregnated with active emitting material the metal surface may be sealed with a dense layer of inactive metal under the non-emissive layer to prevent chemical reaction of the latter with the emitting material.Methods of depositing the surface layers in the desired pattern include coating the cathode's entire large-scale surface contour, followed by machining small concave dimples into the surface, thereby removing the non-emissive layer from the dimpled surfaces from which small beamlets of electrons are focused between the grid conductors without grid interception.Another method is to mask the desired non-emissive areas with an apertured mask having solid elements registered with the desired positions of the grid conductors.

Abstract: A method and apparatus for preventing oscillations in high-current electron guns. Spurious oscillations frequently occur as a result of interaction of the electron stream with the fields of resonant modes of the gun structure. The resonant impedances of the modes are lowered by damping with lossy dielectric or resistive materials which are suited to the high temperature and vacuum environment of electron guns. The lossy materials are located in places shielded from high electric fields applied to the gun. Lossy dielectric materials which are D.C. insulators may be used as insulating supports for gun electrodes.

Abstract: Apparatus to indicate the temperature of an X-ray tube target includes an analog storage circuit to simulate the heat energy stored. Input signals representing the current and the voltage of the electron beam in the tube are multiplied to give a signal representing the instantaneous power input. The power signal is integrated in the storage circuit to give a temperature signal representing the total heat input. The temperature signal is dissipated by a cooling curve circuit representing the heat loss with time. An indicator reads the temperature signal.Input voltage and current signals are processed to refer them to ground before multiplication. The current signal is corrected to set its zero value. The voltage signal derived from a transformer primary is corrected for transformer regulation. To eliminate spurious inputs the power signal is gated to the storage circuit only when a measured current is flowing.

Abstract: Failure inducive operating conditions of an X-ray generator tube are sensed. Some of the sensed operating conditions are events such as hot overload of the target and thermal shock of the target, while other sensed operating conditions include hot target bearing use and thermionic cathode filament heater use. Certain of the sensed operating conditions are integrated, with the integrated output being compared against a predetermined standard to yield a prediction of remaining operating life. Other sensed conditions, if present, are indicative of incipient failure without integration. The integrated signals are stored in electrochemical cells and read out periodically for a prediction of incipient tube failure.

Abstract: An interdigital delay line for crossed field tubes has vanes extending from their interaction faces to a back wall. One end of each vane extends to the end of the face. The other end is cut out behind the interaction face leaving the face projecting. The interaction impedance is almost as high as that of a line with fingers supported by stubs at their centers, while the thermal dissipation is higher, approaching that of a line with vanes extending over the entire length of the fingers.