Abstract: A pencil beam of X-rays is scanned over the surface of the body of a person being examined. X-rays that are scattered or reflected from the subject's body are detected by a detector. The signal produced by this scattered X-ray detector in then used to modulate an image display device to produce an image of the subject and any concealed objects carried by the subject. The detector assembly is constructed in a configuration to automatically and uniformly enhance the image edges of low atomic number (low Z) concealed objects to facilitate their detection. A storage means is provided by which previously acquired images can be compared with the present image for analyzing variances in similarities with the present image, and provides means for creating a generic representation of the body being examined while suppressing anatomical features of the subject to minimize invasion of the subject's privacy.

Abstract: Determination of the quality of blind solder interconnections by X-ray inspection is made possible by forming indicator features on the pads of a component and the pads of the surface on which the component is to be mounted. The indicator features consist of an area which is different in size and/or shape than that of the other pad to be joined. For example, the indicator feature may be a circular region with an area approximately twice that of the pad to which it is to be joined. A relatively large amount of solder is deposited on the smaller pad and the two pads are placed in contact. During reflow, the molten solder on the smaller pad will flow to cover the full area of the indicator feature, indicating that a good interconnection was obtained. The indicator features may also be a different shape from that of the pad to which it is to be joined so that the solder deposited on the pad will take on the shape of the indicator feature when successful interconnection is achieved.

Abstract: A method and apparatus for measuring structural characteristics of a manufactured circuit board containing solder joints by automated real-time digital X-ray radiographic inspection techniques. A circuit board under examination is automatically positioned by a digitally controlled multi-axis positioning system between an electronic X-ray source and an electronic X-ray imaging system. X-rays, in a beam of X-rays from the X-ray source, are directed towards the circuit board. The X-rays are absorbed, scattered and transmitted through the circuit board. The X-rays transmitted through the circuit board are directed upon the X-ray imaging system. The X-ray imaging system converts the transmitted X-rays into digital images which represent the radiographic density of the portion of the circuit board under examination. The digital images are stored within a digital image processor.

Abstract: A nuclear event detector for sensing the occurrence of an ionizing radiation pulse and providing switched outputs in response to the sensing. The detector includes an ionizing radiation sensor which provides a sensor output signal when an ionizing radiation pulse incident thereon exceeds a predetermined threshold level. The detector further includes a pulse timer circuit which is responsive to the sensor output signal for providing a timing signal pulse of a predetermined duration. The detector also includes a latch circuit triggered by the output of the timer circuit which provides a flag signal indicating that an ionizing radiation pulse has been sensed. The latch circuit, timer circuit and sensor are part of a hybrid microcircuit and are disposed in a sealed enclosure with connectors extending from inside the enclosure to outside the enclosure. A first external connector is adapted for connection to a first electrical component for setting the threshold level.

Abstract: Stable lipid-protein membranes are prepared by providing a medium of dissolved and emulsified lipids and dissolved proteins. The medium is applied to an orifice formed in a sheet of material in sufficient volume to provide sufficient lipid and protein to form a membrane across the orifice, which membrane comprises a bimolecular lipid layer with protein molecules interspersed therein. The medium is allowed to dry in the presence of air, and the lipid and protein molecules arrange themselves to form the membrane. The protein is selected to be specifically reactive with a particular chemical substance or a narrow class of chemical substances. When the membrane is exposed to a substance with which the membrane proteins react, a physical characteristic of the membranes is altered. Detection of a change in such membrane characteristic confirms the presence of the substance.

Abstract: An anti-parallax scintillator system images light from a face of a scintillator radiated by penetrating ionizing radiation from a localized source. Radiation from the source will traverse the scintillator along rays forming a cone having its vertex approximately at the source. Scintillator light directed along each such ray is collected and redirected toward an aperture in a screen between the scintillator and the photocathode of an image intensifier. The aperture transmits the redirected light which is then incident upon the photocathode to form an image. Scintillator light not directed along rays from the vertex will miss the aperture and be blocked from the photocathode by the screen. A second embodiment, without an aperture, uses a plurality of mirrors arranged in a quasi-Newtonian configuration to provide anti-parallax imaging.

Abstract: A meat grader grades meat disposed in a bin of predetermined dimensions wherein the meat extends at least about two feet in all directions. A probe includes a housing containing a scintillation phosphor responsive to gamma rays including 1.46 Mev gamma rays from potassium-40 for producing corresponding light pulses of magnitude systematically related to the energy of the incident gamma rays, and a photomultiplier optically coupled to the phosphor for producing corresponding electronic pulses of magnitude systematically related to the magnitude of said light pulse. The probe is inserted into the meat to dispose the phosphor near the center of the meat. A differential pulse height discriminator selectively responds to such of the electronic pulses as are of a limited range of magnitude including that characteristic of the 1.46 Mev gamma rays by producing corresponding discriminated signal pulses.

Abstract: A large area neutron proportional counter is constructed utilizing a large sealed metal box. The interior walls of the box are coated with .sup.6 Li enriched metal. A multicelled proportional counter structure within the internal space defined by the box is fabricated using a hydrogenous plastic. The interior of the box is filled with a counting gas. Wires running through the box, and insulated therefrom, are raised to a suitably high potential so that the counting gas functions in the proportional region to amplify and collect charge from ionizing events in the gas, the wires acting as a anodes and the box as cathode. The cell dimensions are chosen so that .sup.6 Li(n,.alpha.).sup.3 H reaction products will, with high probability, stop in the gas. Compton electrons, on the other hand, will mostly be stopped in the walls or in the hydrogenous plastic cell boundaries. An array of such counters may be utilized for detection of neutron emitting materials passing through a portal.

Abstract: A solid state fast-neutron spectrometer/dosimeter and a detector therefor are presented. The detector comprises a substrate of organic semiconductor material and a coating of a nuclearly inert metal with a Fermi level greater than that of the substrate, the metal being applied so as to form a rectifying barrier with the substrate. Multi-substrate detector embodiments provide greater sensitivity and precision in an incorporating spectrometer/dosimeter. A pulse height analyzer is used to obtain a pulse height distribution from the output of the detector. The pulse height distribution may be converted by means of a microcomputer to yield a neutron energy distribution for spectrometer applications, or a total neutron energy reading for dosimeter applications.

Abstract: A method of detecting the vapors of particular organic materials, such as narcotic vapors, in which a test plate is provided having a surface coated with an antibody specific for a particular organic material. The test plate is exposed to atmosphere in a region where the presence of the organic material is suspected so that, if vapors of the particular organic material are present, the material will react with the antibody and cause an observable change in the optical properties of the test plate.

Abstract: A nuclear method and apparatus determines the temperature of a medium by injecting fast neutrons into the medium and detecting returning slow neutrons in three first energy ranges by producing three respective detection signals. The detection signals are combined to produce three derived indicia each systematically related to the population of slow neutrons returning from the medium in a respective one of three second energy ranges, specifically exclusively epithermal neutrons, exclusively substantially all thermal neutrons and exclusively a portion of the thermal neutron spectrum. The derived indicia are compared with calibration indicia similarly systematically related to the population of slow neutrons in the same three second energy ranges returning from similarly irradiated calibration media for which the relationships temperature, neutron absorption cross section and neutron moderating power to such calibration indicia are known.

Abstract: A method is described for producing ammonia. A catalyst is produced by heating a mixture of carbon and magnesium above the melting point of magnesium in an inert atmosphere. The melt thereby produced is cooled and pulverized. Exposing the catalyst thereby produced to humid air results in production of ammonia. The addition of aluminum or zirconium to the mixture enhances the productivity of the catalyst.