Abstract: A wide dynamic range read-out method for a storage phosphor sheet includes the steps of reading out the storage phosphor sheet once to produce a high exposure image detail signal, and a second time to produce a low exposure image detail signal. The image signals are combined to produce a wide dynamic range signal.

Abstract: An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture and selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration.

Abstract: A device for monitoring the bulk density and/or mass flow rate of a material within a vessel using positron scattering and annihilation radiometry techniques. The positron source is disposed on one side of the vessel having walls while an annihilation region preferably forming a portion of the vessel walls is disposed on the other side of the vessel. A gamma ray detector disposed externally of the vessel and collimated from the positron source detects the absorption of the positrons within the annihilation region. Monitoring the number of positrons absorbed within the annihilation region facilitates estimating bulk density and mass flow rates.

Abstract: A system for detecting the radiant energy emitted from different closely spaced species includes two detectors each having a large entrance angle for receiving the radiant energy, and wavelength selective filters between the detector and species, the transmission vs. wavelength characteristics being complementary, and means for ratioing functions of the detector outputs, the ratio being indicative of the identity of the species.

Abstract: A high-resolution radioisotopic imaging system employs spaced-apart non-contiguous thin and thick electronic collimation detectors arranged about a radioisotopic source field of radioisotopic atoms, each operative for detecting a plurality of gamma rays, or at least one position, or a combination of at least one position and at least one gamma ray. The detectors specify a plurality of emission probability fields which intersect in space to form a reduced emission probability field.

Abstract: What is disclosed is a preamplifier used with each pyroelectric detector in an infrared imaging array system. To bias the preamplifiers either a MOSFET transistor is utilized as a switch that is periodically operated to place charge on the gate of the MOSFET preamplifier transistor to maintain it at its bias level, or an NPN transistor is operated at a level to provide high impedance. When the bias switch is not operated, the associated detector detects and a reading is taken from each detector in the array. NPN transistor switches can be manufactured consistently and their conduction level can be adjusted to balance the gain of all preamplifiers in the detector array. The supply voltage to the preamplifiers in the array is monitored by a feedback circuit which compares a supply voltage to a reference voltage and adjusts the preamplifier bias voltage to compensate for changes in the supply voltage.

Abstract: A phosphor material for a radiation intensifying screen includes phosphor particles which emit light upon radiation excitation, and alkaline-earth metal fluoride. The alkaline-earth metal fluoride is formed in situ on the surface of the phosphor particles through a reaction of a first reactant containing the alkaline-earth metal with a second reactant containing the fluoride to improve the dispersibility of the phosphor particles. The phosphor material is dispersed in a binder and coated on a base support as a phosphor layer to provide a radiation intensifying screen.

Abstract: An infrared imager includes an array of imager elements. Infrared radiation is focussed onto the array by a lens assembly including a plurality of lens elements. The imager array and the lens are within a cold box which includes an infrared-transparent window. For low noise, a spectrum-limiting filter is also located within the cold box, between the lens assembly and the window, at or within the pupil relief distance of the lens assembly. The pupil relief distance is extended by the use of at least one aspheric surface for one of the lens elements of the lens assembly. The mounting structure of the filter is the aperture stop for the infrared imager. The field of view may be reduced, if desired, without significant effect on the noise performance by use of a telescope including a second lens assembly optically identical to the first lens assembly, operated in conjunction with a confocal large-diameter lens assembly.

Abstract: A threshold safety sensor for a sliding door system employs infrared transmitters and a photo diode for detecting traffic at or near the threshold of a sliding door system. The transmitters are pulsed in a time spaced sequence. An input signal derived from the operate initiating signal of the automatic door operator is employed for enabling a latch. The latch sets a relay to a state for maintaining the doors in an open position when traffic is detected in the sensor detection zone.

Abstract: A method for determining the density of substrata by means of a radiation source K comprising a collimator (1) and of a detector comprising a collimator (3), by which method the direction of radiation may optionally be changed in relation to the direction of detection, and the change of the detected signal may be measured. According to the invention the direction of radiation and the direction of detection are situated in substantially the same plane. By deducting the signal of the desirable depth of measurement from a somewhat greater depth of measurement, substantially only the signal originating from singly scattered radiation is obtained, and as a result it will be possible to measure the density at greater depth than previously. On the basis of a spectrum analysis of the spectrum originating from the measurement, the variation of the density with the depth could be obtained.

Abstract: A warmshield reflector for a cryogenically cooled radiation detector has a reflective surface of toroidal shape. The surface has geometric properties which cause a ray emanating from the detector to be reflected such that a ray is imaged as a defocused ring outside of and surrounding the active detector area. Several such segments are located in front of a small, cryogenically cooled detector shield, to provide an overall detector shielding effect similar to that of a larger, cryogenically cooled shield.

Abstract: The present invention relates to a process for the detection of superimposed sheets, the apparatus making it possible to perform this process and the application thereof to bank notes. The process for detecting superimposed sheets by evaluating their surface mass is characterized in that it comprises the stages of passing the sheets oriented in the direction of their width between a beta particle source and a Geiger-Muller counter, counting the number of particles received by the counter by measuring the frequency F.sub.g of the pulses from the Geiger counter to determine the surface mass and eliminating the notes having a high superimposition level by comparison with a limit value.

Abstract: A memory display system is provided including:a recording support medium having a layer of a luminescent material capable of storing energy coming from a light beam, electrodes enclosing the luminescent material and applying thereto an electric field for releasing the previously stored energy in the form of a beam;an optical transmission device placed in the path of said beam;a sensor receiving this beam and converting the intensity of the light beam into an electric signal;a processing circuit receiving said electric signal, processing it and controlling display thereof on a display device.

Abstract: A method of determining the nuclear radiation dosage to which a thermoluminescent crystal, such as a diamond or cubic boron nitride crystal, has previously been subjected, involves the steps of heating the cyrstal up while supporting it against gravity on an upwardly flowing stream of gas. The light which the crystal emits is collected and analyzed to give a radiation dosage measure in accordance with a know relationship between amount of collected light and radiation dosage. The gas stream may be a hot gas stream in which case the hot gas also serves to heat up the crystal. In one embodiment of the invention, the crystal is supported and heated up inside an integrating sphere which collects the emitted light.

Abstract: A radiation image recording and read-out apparatus comprises a secured stimulable phosphor sheet, a section for recording a radiation image on the stimulable phosphor sheet by irradiating radiation to the stimulable phosphor sheet from one surface side thereof, and a stimulating ray source for producing stimulating rays which cause the stimulable phosphor sheet to emit light. A scanning system is provided for two-dimensionally scanning the stimulating rays on the image-recorded stimulable phosphor sheet from the side opposite to the radiation incidence side. A first light guide member faces the stimulable phosphor layer of the stimulable phosphor sheet from the radiation incidence side, and a photodetector is coupled with an end face of the first light guide member for detecting the light emitted by the stimulable phosphor sheet and entering the first light guide member from the surface thereof.

Abstract: The present invention comprises a method for determining the transition point between a portion of a curve comprising a statistically single exponential function and another portion of the curve comprising the composite of said exponential function with another function. The method of the present invention is useful in determining which portion of a composite decay curve is statistically equivalent to a single exponential function. The method of the present invention is particularly useful in the oil and gas industry in connection with the rapid and accurate determination of the decay constant of the formation surrounding a borehole. In the method of the present invention, the measured decay function following radiation of the formation with a burst of fast neutrons is integrated in a plurality of contiguous time gates between the end of the neutron burst and the decay to background radiation levels.

Abstract: A two-axis quartz fiber passive tilt meter which includes housing and a quartz fiber suspended from the housing for conducting radiation and emitting the radiation from a distal end thereof. A pendulous mass is suspended from the quartz fiber and a damping fluid in the housing surrounds the quartz fiber and the mass. A detector senses the position of the spot of radiation emitted from the quartz fiber.

Abstract: Gamma rays radiated from a radioisotope injected into a subject under examination are detected by a scintillation camera, and position signals indicative of the detected position of the gamma rays and an energy signal are applied to a data-processing unit for imaging the distribution of the radioisotope within the subject. A pulse height analyzer analyzes an energy discrimination signal and provides an imaging control signal when the pulse height of the energy discrimination signal falls within a window of interest. The data-processing unit is responsive to the application of the imaging control signal to thereby image the distribution of radioisotopes within the subject on the basis of the position signals and the energy signal. The energy discrimination signal may have a pileup waveform in which at least two peaks are produced substantially at the same time due to simultaneous detection of gamma rays.

Abstract: An apparatus and method for detecting and analyzing the emissions or effluents from gas or oil combustion so as to discriminate between them. A spectrometer detects the spectra of a combustion effluent or exhaust. Identifying features of carbon dioxide and water vapor are selected at predetermined wavenumbers. The ratio of the relative intensities of the identifying features of carbon dioxide and water vapor is then computed, which results in the discrimination between oil and gas effluents.

Abstract: The present invention pertains to a large-sized X-ray photography panel. This panel comprises several modules placed end to end. Each module comprises a network of photosensitive detectors with the same number of columns as the panels but with a smaller number of rows. Each module has its own addressing and reading means. The addressing means are located on an edge of the insulating substrate that bears the detectors. The reading means are located on the other side of the substrate from the detectors. A screen, which is opaque to the radiation to be detected, is interposed between the substrate and these means. These means are liked to the column connections coming from the opposite side of the substrate by connections along one of the side surfaces of the substrate.