Abstract: A method of measuring an accelerating voltage applied to an x-ray source to produce x-rays includes applying an accelerating voltage to an x-ray source to produce x-ray radiation having an axis; diffracting first and second portions of the x-ray radiation that are symmetrically disposed relative to an axis with a single crystal material to produce two spectra of the x-ray radiation, each spectrum including continuous x-ray radiation having an end point energy at the maximum energy of the x-ray radiation; forming an image of the spectra of the x-ray radiation including respective end point energies; and measuring the separation of the respective end point energies of the spectra of the image and, thereby, determining the accelerating voltage applied to the x-ray source.

Abstract: An oxygen-sensing element particularly for use in the exhaust stream of an internal combustion engine. In one embodiment, the sensing element may be a tubular solid electrolyte body with a transverse web forming a relatively shallow recess at one end of the body and a relatively deep tube at the other. Separate electrodes are formed on the surface of the body proximate the recess and on both opposing sides of the web. A porous plug disposed in the recess covers one of the electrodes. When the electrode on the surface of the body is exposed to the exhaust stream of a fuel-rich air-fuel mixture, the EMF across that electrode and the electrode on the underside of the web, which is exposed to fresh air, is indicative of the oxygen content of the exhaust stream.

Abstract: A method of electrodepositing a doped compound semiconductor film including tellurium and a metal selected from Group IIB of the Period Table of Elements by adding an effective concentration of dopant ions to the electrolyte bath. Cadmium telluride, mercury cadmium telluride and zinc cadmium telluride may be doped with copper, silver and gold. The conductivity type of the electrodeposited doped layers may be changed by a heat treatment. Thin film photovoltaic cells incorporating the doped layer to form a heterojunction with a semiconductor layer of the opposite conductivity type show substantial improvements in open circuit voltage, fill factor and efficiency over similar devices employing undoped electrodeposited layers.

Abstract: A light pen for converting a conventional graphics plotter into a photoplotter includes a housing containing an electrically powered light source, a battery and a normally open switch. The housing has an aperture opposite the light source. The light pen replaces an ink pen in the plotter. When the light pen is urged against a photosensitive sheet in the plotter, the normally open switch is closed, the light pen is energized and the light pen is transmitted to the sheet to illuminate it. The self-contained light pen is free of trailing electrical and optical cables that might interfere with plotter speed and accuracy.

Abstract: An array for sensing the relative intensity of electromagnetic radiation at a plurality of locations employs a network of photodiodes and non-photoresponsive diodes. A first terminal of each photodiode, e.g. the anode, is electrically connected to a common point which is one terminal of the array. The non-photoresponsive diodes are connected in like-polarity series. The second terminal of each photoresponsive diode is connected to a different connection of non-photoresponsive diodes in the string. The array is scanned with a voltage ramp signal and each change in current flow indicates an illuminated diode. The particular voltage at which current flow changes discloses which photodiode is illuminated. Embodiments of the novel array can be made monolithically without a significant number of conductor cross overs.

Abstract: An improved, low cost photovoltaic device responsive to ultraviolet radiation includes a body of amorphous silicon having a front contact formed of a thin film of a transparent, electrically conductive oxide. In order to achieve desired quantum efficiencies in the spectral region from 200-400 nm, the oxide film is less than 50 nm in thickness and most preferably is about 15 to 30 nm in thickness. A metallic current collector may be disposed on part of the oxide film to reduce resistive losses in current collection. The amorphous silicon body may include a P-I-N structure or a doped film disposed on an oppositely doped crystalline silicon layer. In some embodiments of the device, the amorphous silicon region or body disposed in contact with the oxide film is preferably microcrystalline silicon.

Abstract: An improved fuel cell assembly includes a plurality of series-connected fuel cells each including an electrically conductive separator, a compressed or sintered oxide powder cathode contacting the separator, a solid electrolyte contacting the cathode and a compressed or sintered powder anode contacting the electrolyte. Each of the separator, anode, electrolyte and cathode includes two internal holes each at least partially in registration with each other so that a fuel and an oxygen-containing gas may be admitted to separate tubes in the cell. Preferably, a gasket is disposed in the opening in the cathode receiving the fuel to shield the cathode from the fuel. A second gasket is disposed in the opening in the anode receiving the oxygen-containing gas to shield the anode from oxygen. Oxygen admitted to one of the tubes reaches the anode by first diffusing through the cathode and then being ionically conducted through the electrolyte to the anode. Oxygen at the anode reacts with the fuel, releasing heat.

Abstract: A three layer, photovoltaic structure having polycrystalline semiconductor layers disposed in series optically and in sequential touching contact includes a relatively wide optical bandgap energy window layer, a light-absorbing layer and a third, relatively wide bandgap energy layer that forms a minority carrier mirror with the light-absorbing layer. All three layers have different compositions so that the structure includes two heterojunctions. The light-absorbing layer and third layer are of the same conductivity type. The structure is conveniently realized using II-VI semiconductor compounds such as a cadmium sulfide or zinc sulfide window layer, a mercury cadmium telluride, cadmium telluride, zinc cadmium telluride or mercury zinc telluride light-absorbing layer and a third layer of cadmium telluride, zinc telluride, zinc cadmium telluride, mercury cadmium telluride or cadmium manganese telluride. Cadmium is present in at least two of the three layers of the novel structures.

Abstract: A method and apparatus for measuring the quantity of bubbles in a gas/liquid mixture. An ultrasonic wave is launched into the mixture and the magnitudes of two reflected waves are measured and compared. The logarithm of the magnitudes of the reflected waves is a measure of the quantity of gas content. The method and apparatus are suitable for measuring gas bubble content repetitively in a mixture turbulently flowing through a conduit.

Abstract: Lightweight, compact apparatus for detecting sudden changes in the concentration of at least one selected gas provides a warning when said gas concentration increases suddenly. In one embodiment, a chemically sensitive field effect transistor provides a sensing signal two amplifiers having different overall gains and widely different time constants. Detection of sudden gas concentration changes causes the relative magnitudes of the amplifier output signals to be inverted triggering a warning. The apparatus may occupy less than 1.25 cubic inches and weigh less than 4 ounces so that it may be worn by an individual throughout his work place.

Abstract: A three layer, photovoltaic structure having polycrystalline semiconductor layers disposed in series optically and in sequential touching contact includes a relatively wide optical bandgap energy window layer, a light-absorbing layer and a third, relatively wide bandgap energy layer that forms a minority carrier mirror with the light-absorbing layer. All three layers have different compositions so that the structure includes two heterojunctions. The light-absorbing layer and third layer are of the same conductivity type. The structure is conveniently realized using II-VI semiconductor compounds such as a cadmium sulfide or zinc sulfide window layer, a mercury cadmium telluride, cadmium telluride, zinc cadmium telluride or mercury zinc telluride light-absorbing layer and a third layer of cadmium telluride, zinc telluride, zinc cadmium telluride, mercury cadmium telluride or cadmium manganese telluride. Cadmium is present in at least two of the three layers of the novel structures.

Abstract: An electrically small, efficient electromagnetic structure, that may be used as an antenna or waveguide probe, having an electromagnetically closed, velocity-inhibiting conducting path, for supporting a standing, inhibited-velocity wave in response to the flow of an electrical current through the path and a process for establishing the standing wave. Use of the structure is particularly advantageous at the lower end of the electromagnetic spectrum, where various embodiments produce purely vertically polarized radiation in directional and omnidirectional patterns. Various embodiments of the structure include multiple conducting paths and image means to complete the conducting path. Embodiments of the structure may be used to excite the earth-ionosphere cavity at the Schumann resonances.

Abstract: Semiconductor dopant sources are prepared by mixing particles of elemental silicon and at least one dopant oxide and heating the mixture to a temperature sufficient to initiate a reduction reaction while excluding external oxygen sources from affecting the reaction. The reaction can be initiated in a furnace, provided the gaseous ambient is controlled, or can be initiated in air if the mixture is heated sufficiently rapidly, e.g. by heating with electromagnetic energy at microwave frequencies. The dopant source produced includes a fused, amorphous matrix of silicon-oxygen-dopant atoms containing inclusions of elemental dopant and, preferably, inclusions of elemental silicon. Embodiments of sources prepared from antimony trioxide slowly evolve antimony, have a long life and repeatedly and predictably dope silicon at commerically useful levels.

Abstract: An oxygen-sensing element particularly for use in the exhaust stream of an internal combustion engine. In one embodiment, the sensing element may be a tubular solid electrolyte body with a transverse web forming a relatively shallow recess at one end of the body and a relatively deep tube at the other. Separate electrodes are formed on the surface of the body proximate the recess and on both opposing sides of the web. A porous plug disposed in the recess covers one of the electrodes. When the electrode on the surface of the body is exposed to the exhaust stream of a fuel-rich aur-fuel mixture, the EMF across that electrode and the electrode on the underside of the web, which is exposed to fresh air, is indicative of the oxygen content of the exhaust stream.

Abstract: The use of multiple field effect transistors, wherein only one transistor is sensitive to the presence of a particular element, is disclosed whereby similar responses to temperature and/or humidity fluctuations may be subtracted yielding a response to a particular element that is relatively insensitive to temperature and/or humidity variations.

Abstract: A solid state double layer capacitor includes an organic electrolyte doped with a soluble salt to render the electrolyte ionically conductive.

Abstract: A novel dual ion beam sputtering process for depositing thin films of high density is described. One of the ion beams contains relatively heavy sputtering ions, such as argon ions, for ejecting atoms from a target. The second ion beam is also directed at the target and contains ions having energies of at least 3 electron volts and less than 20 electron volts. The products of the beams are collected on a substrate as a thin film. High density, hydrogenated amorphous semiconductor films, oxide and nitride films, and other films, may be deposited according to the process. The films have densities nearly equal those observed for bulk samples of the same materials. Hydrogenated amorphous silicon films deposited by the process exhibit enhanced photoconductivity.

Abstract: A bedding device for use with an animal leg hold trap includes a platform providing support for the free jaw of the trap when the trap is in its set position. In one embodiment, the platform contains one or more integral channels for releasably retaining in the device at least one frame member of the trap. The channels are defined: (i) by floors that are shaped to accommodate the contour of a frame member; and (ii) by convergent, upstanding resilient side walls for snapping the frame member into position and releasing it upon triggering of the trap. In another embodiment, one or more resilient clips are inserted from the bottom of the platform through holes in the platform. The clips retain a trap frame member between their convergent legs. The platform is preferably formed from a single piece of material, most preferably a resilient polymer, such as polypropylene, polystyrene and teflon, that does not absorb odors.

Abstract: Apparatus for converting relatively high, variable frequency, variable amplitude electrical power into substantially constant amplitude and substantially constant, relatively lower frequency power of a preselected waveform. The power source signal is divided into a number of varying amplitude, same frequency segments. The segment having the amplitude nearest that of the preselected waveform is transmitted by a switching network during each of many time periods. The switching network is preferably controlled by a microprocessor that senses the amplitudes of the segments and compares them to the desired waveform amplitude as a function of time. The microprocessor provides control signals to the switching network in response to the comparison. Because the low frequency output signal is constructed with reference to a memorized signal, the output signal is particularly stable in spite of variations in the power source signal.

Abstract: A photovoltaic array module incorporating a plurality of photovoltaic cell strips (11). Each cell strip (11) incorporates an electrically conductive substrate layer (21), a semiconductor body (22) deposited on the substrate layer (21), and a transparent electrically conductive layer (23) deposited on the semiconductor body (22). Each cell strip (11) further incorporates a preformed thin-film unitary grid and interconnect structure (20) electrically associated with the transparent electrically conductive layer (23) thereof so as to collect and remove electrical current therefrom and electrically to interconnect the cell strips (11). A first busbar (12) and a second busbar (13) are connected to the end cell strips (11) of the array to collect the electrical energy generated thereby.