Abstract: A current shunt, for measuring rapidly changing values of current, providing a voltage indicative of the current wave that is free of any inductive effects of the shunt is provided by forming the shunt from two dimensionally identical elements but each having a different electrical resistivity and adding the voltage drops across the elements. The elements have equal and cancelling induced electrical voltages leaving an electrical voltage free of inductive effects and that is proportional to the current flowing through the shunt.

Abstract: The permeability and resistivity of metal sheets including those installed in enclosing structures, are nondestructively determined by injecting a unit-step pulse of current into an exposed surface of the sheet and measuring the surface voltage gradient between a pair of contacts located between the current injection contacts. The permeability and resistivity of the metal determines the rate of diffusion of current into the surface and therefore the rate of decrease of this surface voltage gradient. At steady-state the current density will be uniform throughout the thickness of the sheet resulting in the surface voltage gradient stabilizing at a value depending on the resistivity and thickness of the metal.

Abstract: A Zener diode voltage sensing circuit senses when the 115 volt, 400 Hz primary power source to a conventional 8 Hz two-phase mass flowmeter is below approximately 80 volts and through an amplifier, a frequency halving flip-flop, and a quad NAND gate halves the frequency from 8 Hz to 4 Hz so that the impeller of the two-phase drive motor will start or continue rotating, then as the primary voltage rises above the 80 volt predetermined amount, and after approximately a one-second delay, the 4 Hz, two-phase drive frequency is changed to the normal two-phase 8 Hz impeller driver voltage.

Abstract: An electrometer for conventional pocket radiation dosimeters is disclosed in which the moving element of the electrometer is a carbon fiber. The fiber is spun from polyacrylonitrile homopolymer yarn and has a diameter of approximately 7 microns before carbonization. The polyacrylonitrile homopolymer fiber is conventionally preoxidized at approximately 270.degree. C before conventional carbonization at approximately 1200.degree. C. The resulting working fiber has a round cross sectional diameter of approximately 4 microns and a modulus of elasticity of approximately 15,000,000 psi. The fiber is mounted in a conventionally loop shaped electrometer frame by crimping the ends of the fiber into tabs on the frame.

Abstract: Junctions of the signal leads from equipment monitoring sensors to conventional cable lines are made by forming reference junctions of the signal leads in shielded temperature controlled oxygen-free hardened copper slugs embedded in a beryllium oxide block. Sensors may readily be changed since the junctions of the signal leads in the copper slugs are made through removable plastic taper pins forming pressure contacts of the leads in recesses formed in the copper slugs. The universal reference junctions are particularly suited for making connections to the leads of sensors which are located in intense electrical fields.

Abstract: In a Vuilleumier cryogenic refrigerating system for operation wherein the source of thermal energy for the hot cylinder during periods of interrupted electrical energy is supplied by heat of fusion of the thermal energy storage material, the container for the thermal energy storage material is made the electrical heating element for both the refrigerator and the thermal energy storage material.

Abstract: A vertical multijunction solar cell fabricated with the junction channels perpendicular to a ribbed electrical grid structure provides an improved vertical multijunction solar cell having increased mechanical strength and decreased electrical resistance.

Abstract: Collimated ultraviolet light radiation at wavelengths of 2537A and 3129A is alternately directed across the space to be monitored for smoke indicative of a fire. A "cats eye" mirror at the far side of the monitored space returns the ultraviolet rays to a photomultiplier detector adjacent the light source. Smoke, for example pine smoke having a particle mean diameter of 1.4 to 3.0 micrometers, will attenuate the shorter wavelength beam much more than the longer wavelength beam. Approximately 1.3 times greater attenuation is inflicted on the 2537A beam than on the 3129A by the pine smoke. Thus, returning beam signals having this ratio of signal levels will provide an indication of a pine fire. Particles of a different diameter intercepting the beam will produce a different ratio of attenuated signals.

Abstract: The structure of a cell for a metal-gas battery is disclosed in which the cell components comprising the electrodes, separators, and electrolyte reservoirs are substantially planar structures, circular in shape and having a hole at the center. These components are stacked on a common axis perpendicular to their planar surfaces to form individual electrochemical cells. Individual cells may be similarly stacked to form a battery. The stack of flat ring-shaped components comprising a cell is enclosed in a plastic insulating cell case member providing a reactant gas manifold space at the inner circumference of the cell stack components inside the plastic enclosure. On the inner circumference of the plastic cell case member are positioned ports covered with a non-wetting porous plastic membrane of Teflon.

Abstract: A Nd:YAG laser operating in a dual functioning cavity with a Ba.sub.2 Na(NbO.sub.3).sub.5 frequency doubling crystal provides two frequencies of laser radiation, one frequency double the other, to provide a laser beacon beam at a wavelength of approximately 1.06 micrometers and a high data rate beam at a wavelength of approximately 0.53 micrometer.

Abstract: An improved transverse-discharge gas laser tube is provided by positioning thermionic cathodes diametrically opposite each other across the plasma location with anodes positioned at 90.degree. to the cathodes all contained within an electron repelling envelope. Laser configurations for both large and small circular cross-section plasmas are disclosed. A thermionic cathode plasma slab laser with a magnetic field that may be modulated to provide modulation of the laser beam is also disclosed.

Abstract: In a charge-coupled-device the registers of two adjacent arrays are interleaved in a novel serpentine structure to provide a refresh-cell width of four times the width of a single-shift register.

Abstract: A sealed extensible bellows containing freon and a flexible wick provide a heat pipe, and fixed end of which is attached to a heat sink (a cold body), the other movable end of the bellows carries a thermally conductive plate that moves from a nonengaging relationship to an engaging relationship with a temperature regulated surface at a predetermined temperature of the cold body.

Abstract: A lightweight and improved nickel-hydrogen cell composed of a plurality of parallel connected cell plates is provided by making the conductor leads from each of the plurality of plates to the electrical terminals of the cell have substantially the same electrical resistance, and contain the minimum amount of material.

Abstract: The velocity of a fluid flowing through a flow channel, relative to the flow channel, is measured by passing parallel rays of light through the fluid perpendicular to the flow and through an artificially-introduced transfer function device such as a grating or double reflective mirror, and then focusing the light on a photodetector. The basic principle by which embodiments of the invention operate involves the spatial convolution of the light intensity pattern established by the artificially-introduced transfer function with the flowing stream. The transfer function is associated with a known spatial alteration of the light beam. The light intensity pattern resulting from variations in the properties of the flowing stream is characterized by fluctuations which are transported with the flow velocity. These variations of the flowing stream are manifested as localized changes in density, and absorptivity and reflectivity of the light as it traverses the flow channel.

Abstract: The body current of a TWT (traveling wave tube) is measured by generating a voltage that is proportional to the difference between the cathode and collector currents of the TWT without materially affecting either by passing the cathode and collector currents through separate transformer windings, wound in opposition, on both a linear core transformer and a nonlinear core transformer with separate windings coupling each transformer to the other. A voltage pulse is introduced into another winding on the nonlinear transformer causing a current flow in the circuit coupling the two transformers, the voltage magnitude of which is proportional to the difference between the cathode and collector currents which is the body current.