Abstract: For conducting very high microwave power at very high frequencies, circular waveguide transmitting a circular-electric-field mode is used. The vacuum-tight window of an electron tube is often the element with lowest power-handling capability. The inventive window has two dielectric plates with a space between them. There is a gap in the waveguide inner wall through which a dielectric fluid is circulated between the plates to cool them. The gap leads to a region containing wave-absorbing material such as water to absorb modes other than the circular-electric-field mode.

Abstract: Improvements are disclosed in an ultrasonic display and recording system of the type utilized in diagnostic medicine with particular applicability in cardiovascular diagnosis. The system includes a multi-element transducer for generating and receiving ultrasonic energy which is propagated into and reflected back from the cardiovascular region of the patient being examined, and also includes means for generating a two-dimensional real time display and/or image of the zone of examination. TM recording means are associated with the system and may be actuated to effect a TM recording corresponding to a preselected region of the real time image being observed. An ECG output signal is also displayed in real time with the two-dimensional image, and photographs of the displays may be produced at selected points in the ECG cycle in accordance with a setting made by the system operator.

Abstract: A delay line having an inductive component in which inductive windings are made on multiple post bobbin units to maintain spacing and alignment. Two multiple bobbin units are collectively wound and then secured together with the bobbins interfitting to form a rigid, precisely aligned element, with the wires from each bobbin positioned for ease of connection. The inductive component is mounted on the base of a dual in-line package (DIP), capacitors are secured in the inductive component and the electrical connections are made to connect the inductors and capacitors to the contact pins of the DIP. The assembly is then potted or otherwise enclosed for protection.

Abstract: In an electron gun having a control grid in contact with the face of the cathode, unwanted thermionic emission from the cathode can be effectively suppressed by applying a thin (1 micron) coating of boron nitride to the surface of the control grid. The boron nitride has low thermionic emission itself and, in addition, has an unusual ability to shed or eliminate any deposits of emissive material such as barium or its oxides which come in contact with the boron nitride layer. For optimum performance and longest lifetime, the boron nitride layer is applied over a pyrolytic graphite layer which may be the conductive grid itself.

Abstract: A walking drag line having an oxcillating wheel segment, a vertical axis roller slot coupling the wheel segment and the walking drag line, a shoe for stepping the walking drag line and a track frame assembly coupling the oscillating wheel segment and the shoe. The crankpin which is journalled into the wheel segment imparts a reciprocal motion in the wheel segment having both horizontal and vertical components. The wheel segment rotates about the axis of a roller axis pin journalled in the vertical axis roller slot and rotates on a track surface of the shoe on the curved outer surface of the wheel segment without slippage.

Abstract: A phased array ultrasonic imaging system is disclosed which combines aspects of both dynamic and pseudo-dynamic focusing. The system includes a linearly arranged array of side-by-side transducers adapted for propagating ultrasonic energy into a body to be ultrasonically examined and for receiving reradiated sonic energy from points within the body. A signal channel is connected to each of the transducers for activating same to propagate the sonic energy and for receiving electrical signals from the transducers (which correspond to the reradiated energy). Controllable delay means are provided in each of the channels for introducing linear phase shifts in the electrical signals proceeding in the channels during both transmission and reception to thereby azimuthally steer the transducer array. Means are further provided for processing the received signals proceeding through the channels and for combining same to effect a visual display of the bodily portion being examined.

Abstract: In a travelling-wave tube for very high frequencies the slow-wave circuit is formed of four metal combs having teeth pointed toward the electron beam. The combs are arranged in two pairs. The teeth of the two combs in each pair extend inward from opposite sides of the beam and are axially aligned to form the electrical equivalent of a half-wave bar or ladder structure. They may or may not be joined at the tips because those are low-current points. The teeth of one pair are at right angles to those of the other pair and are displaced axially to interleave with them. Each comb is preferably made from a single piece of copper to provide better dimensional precision, low circuit loss, mechanical durability and high thermal capability.

Abstract: A pulse damper for use in high-pressure liquid pumping applications such as liquid chromatography comprises a length of flattened polytetrafluoroethylene tubing that can be coupled to the high-pressure liquid flow line. The flattened tubing is enclosed within a liquid-tight housing structure completely filled with a compressible liquid, and the end of the tubing are coupled to the high-pressure flow line by fittings mounted inside the housing structure. When a transient pressure variation occurs in the flow line, the cross-section of the tubing changes from a flattened elliptical configuration to a more rounded configuration as the pressure pulse temporarily overcomes the stresses that tend to maintain the tubing in its flattened configuration. The restoring force of the compressible liquid in the housing structure surrounding the tubing prevents expansion of the tubing beyond a desired limit during a pulse, so that the tubing cannot burst when its cross-sectional configuration changes.

Abstract: A gun for a linear-beam electron tube has a control grid for modulating the beam current which consists of an array of conductive web elements whose spacing from each other is much larger than their spacing from the concave emissive surface of the cathode. It was found that when this condition is met the grid can be operated at cathode potential while beam current is being drawn without distorting the electric accelerating field enough to ruin the focusing of the beam. Thus, when the grid is used to pulse the beam current on and off, it can have zero bias in the "on" condition, whereby the pulse modulator can be greatly simplified.

Abstract: Apparatus for making the inductive component of a delay line containing multiple wire wound bobbins in a linear assembly. The component comprises a pair of multiple post bobbin units secured together with the bobbins interfitting in a row, each bobbin being wire wound. The apparatus simultaneously winds all bobbins on each unit with a uniform number of turns of wire, then secures the two units together while maintaining tension on the wire to prevent slippage. Bobbin units are fed into holders which are indexed successively to a winding station, an adhesive application station and a joining station, the completed components being wound on a storage spool while still in a string on the wires. The winding heads are driven to move in an elliptical path around the bobbin posts to provide clearance between the posts and to maintain constant wire tension in the windings.

Abstract: An instrument for the analysis of a sample material to detect the presence of specific substances that thermally decompose into electronegative species comprises a sensitized surface, means for heating the sensitized surface in a gaseous environment to generate a gaseous boundary layer adjacent the sensitized surface, means for causing the sample material to interact with the sensitized surface to form negative ions, a collector electrode maintainable at a different electrical potential from the sensitized surface to cause a current of these negative ions to the collector electrode, and means for measuring the ion current. The sensitized surface is formed on a ceramic body that is impregnated with an alkali metal. The composition and temperature of the sensitized surface, and the composition of the gaseous boundary layer are selected according to the specific substance to be detected.

Abstract: A high power gyro device includes a source of electrons. The electrons from this source are formed into a beam in which individual electrons are made to follow helical paths by a DC magnetic field. The angular velocity of the beam electrons is modulated as the beam passes through an oscillating electric field in a resonant cavity or waveguide so that a high power electromagnetic wave is established in the region as a result of an interaction between the beam and field. A collector for the beam is positioned on the axis, while an output waveguide for the wave is positioned at right angles to the axis. Upstream of the collector, the wave is reflected to the output waveguide by a reflecting surface having an aperture for passing the electron beam to the collector.

Abstract: A magnetic circuit useful in crossed field tubes and the like. At least one permanent magnet assembly is provided which includes a high flux density magnet (as Alnico), a high coercive force magnet (as Samarium Cobalt) with an end area larger than the facing end of the high flux density magnet, and polarized oppositely thereto, and an iron transition member sandwiched between the two magnets. This isolates the high coercive force magnet and concentrates its flux. When used with a second such magnet assembly to create a high magnetic flux density in a gap therebetween, for example, in the interaction space of a crossed field tube, a higher flux density is achieved in the gap than would be the case utilizing the high flux density magnet alone within the available dimensional limitations. This is particularly so in an open magnetic circuit application having only a non-magnetic flux return path.

Abstract: An object surrounded by media of differing acoustical impedances (e.g., an anatomical organ surrounded by other kinds of tissue within the human body) is acoustically imaged by an array of ultrasonic transducers affixed to the outer surface of an ultrasonic lens. In a preferred embodiment, the lens is homocentric, with the common center of curvature of the inner and outer surfaces of the lens being located at a relatively small acoustic aperture in the body so that object points distributed over a relatively large solid angle from the aperture can be imaged with minimum lens aberations. Where the object to be imaged is a human heart, the acoustic aperture is most conveniently located at an intercostal space between adjacent ribs.

Abstract: An electrically resistive heater consisting of a helix of resistive wire, the helix being shaped into a toroid or a spiral, with the electrical return lead extending coaxially through the helix so as to provide a magnetic field of equal magnitude and opposite sense to that produced by current in the helix to cancel the magnetic fields.

Abstract: An electrical-to-acoustic wave transducer contains an array of piezoelectric elements connected to wave-delay circuits to generate a directed acoustic beam and to receive a similarly directed, reflected beam. The distance of a reflecting object is sensed by the time delay of the reflected wave. The apparatus is adapted to sense reflections from both the Fresnel region and the far-field of the array. During the time when reflections from nearby objects in the Fresnel region are received, the effective aperture of the array is reduced by disconnecting elements near its extremities or reducing their gain, producing a narrower beam for improved angular resolution.

Abstract: A dense film of silicon nitride is deposited by a plasma discharge in a vapor of azidotrimethylsilane (AZS) (CH.sub.3).sub.3 SiN.sub.3. AZS is less reactive and easier to handle than the previously used silane SiH.sub.4. The resulting film is more stable chemically than the silicon nitride produced by other processes. It is useful for protective and anti-reflective coatings, for insulating, and for masking, particularly on semiconductive devices.

Abstract: A lens or mirror is employed to concentrate sunlight onto a photovoltaic cell. The cell employs a broad conductor around the periphery of its active surface, and narrow higher resistance conductor strips over the inner part of the surface. The cell and mirror are sized, positioned and shaped such that the image of the sun on the cell's surface is non-uniform, with a proportionately higher concentration of light falling near the periphery of the cell adjacent the peripheral conductors. Thus, the generated current is greater at the periphery, so that less energy is lost due to series resistance of the surface conductors, for more efficiency compared to a uniformly illuminated cell. The non-uniformity can conveniently be obtained by utilizing the natural spherical aberrations of a simple spherical mirror or lens. Also the cell can be positioned relatively close to the mirror outside the focal plane, so that the illuminated area on the cell is larger than the focused image of the sun in the focal plane.

Abstract: A fibrinogen monitor for use in monitoring the concentration of iodinated fibrinogen distribution in the calf and thigh veins of bed-restricted patients. The fibrinogen monitor is an improved scintillation detector which a hospital staff member can manipulate using one hand to detect and record scintillation events at measured points along the leg of a patient while leaving the other hand free to aid in positioning the leg. The output of the monitor is digitized and provided both as a visual display and as a hard-copy record. The geometrical configuration of the probe of the monitor provides for increased sensitivity to gamma radiation without an attendant increase in probe size.

Abstract: The allowable gain of a crossed-field amplifier tube is increased by tapering the slow-wave interaction circuit to a smaller spatial period in the direction of circuit power flow. Concurrent variation of the electron beam drift velocity by tapering the dc electric or magnetic field further improves the gain and efficiency.