Abstract: A wavelength-locked laser gaseous species monitor including a variable wavelength laser with a laser output actively stabilized to a wavelength at or near an absorption wavelength of the species being monitored. The laser is modulated about that wavelength to establish a modulated output with a known frequency and bandwidth. The modulated output is passed through the sample being monitored and then collected. An even harmonic of the collected output with respect to the modulation frequency is determined, and the presence in the sample of the species being monitored is detected from the even harmonic signal.

Abstract: An improved intensifying lead screen for use with photographic, industrial X-ray films, having a low propensity to produce electrostatic changes, is described. This screen comprises a lead foil adhesively applied to a polyester support with an overcoat or protective layer applied over the lead layer and coated thereon, a layer of a fluorosurfactant.

Abstract: A light beam scanning system has a sheet holding member which is provided with a concave cylindrical sheet support surface on which a recording sheet is supported. A suction box draws the recording sheet against the sheet support surface by suction. A spinner has a light deflector mirror which reflects a scanning light beam on the central axis of the cylindrical sheet support surface toward the recording sheet on the sheet support surface and a condenser lens system which converges the reflected scanning light beam on the recording sheet. The light deflector mirror and the condenser lens system are integrally rotated about the central axis to cause the scanning light beam to scan the recording sheet in a main scanning direction. A sub-scanning mechanism moves the sheet holding member in a sub-scanning direction parallel to the central axis relative to the spinner.

Abstract: A pass-line independent measuring device for producing thickness related measurements (e.g., thickness, basis weight, density, etc.) of a moving web. The thickness measurements themselves are based on a nuclear source and detector mounted on one or both sides of the web, the source emitting radiation and the detector detecting emitted radiation from the web as an uncorrected measure of web thickness. An ultrasonic distance measuring means is fixedly associated with either the source, the detector, or both and continuously directs ultrasonic pulses in a direct path to the web, measures reflections in substantially a similar direct path, and by means of the time delay between a pulse and its reflection determines the actual pass-line of the web between the source and detector. The pass-line is used with a correcting function to correct the nuclear readings and provide a substantially accurate measure of web thickness corrected for pass-line.

Abstract: A movable calibration collimator for a radionuclide emission tomography camera, and a calibration system using same, having a wall of material which is opaque to radionuclide emissions and is movable in a first direction relative to the camera. One or more patterns of openings are defined by the wall to pass radionuclide emissions. The openings of each pattern are aligned in a direction transverse to the first direction to provide an array of camera images upon movement of the wall relative to the camera. The number of images generated for the array are greater than the number of openings. A method of using such a calibration collimator to perform linearity correction involves installing the calibration collimator and a line source of radionuclide emissions, acquiring a camera image of the pattern of openings, and incrementing the calibration collimator for a desired number of increments. Each camera image, collected at each position of the collimator, has a position image for each opening.

Abstract: A method and apparatus for correcting for the ballistic deficit effect that occurs when determining the spectra of radioactive substances with an ionizing radiation detector. Two pulses derived from each output pulse of the detector, each having different peaking times but both containing effects of the ballistic deficit, are compared to produce an error signal related to the difference of the peak heights of these two pulses. A part (or all) of the error signal is added to one of the pulses to produce a corrected amplitude pulse. In order to effectively compare the two pulses, each is separately stretched at its peak height. The corrected amplitude pulse is reformed for better handling by multichannel analyzer analog-to-digital converters, with a plurality of these reformed corrected amplitude pulses then being analyzed by the multichannel analyzer to achieve a nuclear spectra for which the ballistic deficit has been corrected.

Abstract: Preferred embodiments include a monolithic uncooled infrared detector array of bolometers fabricated over a silicon substrate (142); the bolometers include a stack (144) of oxide (146) TiN (148), a-Si:H (150), TiN (152), oxide (154) with the TiN forming the infrared absorbers and resistor contacts and the a-Si:H the resistor with a high temperature coefficient of resistivity. The resistor is suspended over the silicon substrate (142) by metal interconnects (154 and 156) and related processing circuitry is formed in the silicon substrate (142) beneath the resistor.

Abstract: Permeability of structures consisting essentially of dispersions of barrier resins in permeable structural resins can be predicted by the application of near infrared spectroscopy, within the wavelength range of 600-2500 nm, especially 1100-2500 nm. The method requires establishing a correlation between base permeabilities of samples of a Training set and their near infrared spectra, developing from that correlation a predictive equation, verifying the accuracy of the predictive equation on samples of a Validation set, and applying the predictive equation to the determination of the permeabilities of unknown samples.

Abstract: A detector element signal comparator system is used for noise reduction and image enhancement by comparing the output of any detector signal processor within a module to the output of any other detector signal processor within the same module. The detector element signal comparator system has a comparator for each detector signal processor, a comparator bus to connect the output of any detector signal processor to the comparators of all other detector signal processors, a switch for each detector signal processor to selectively connect each detector signal processor to the comparator bus, and an output bus for communicating the comparator signal from the detector element signal comparator to the next stage of signal processing.

Abstract: A system is disclosed for determining the position of at least one target by triangulation, comprising two passive sighting devices which measure the intensity of radiation received along a sighting line which scans a vertical sighting plane. They are disposed at a distance from each other along the same vertical axis and are driven in rotation about this common axis so that their sighting planes merge. A circuit extracts the angular coordinates of the target, relative to each of the sighting devices, and computes the distance of the target by triangulation in the vertical sighting plane.

Abstract: A flame detector has a sensor for producing a digital waveform representing a flickering flame. Its turning points are detected and the magnitudes between successive such points are measured. The value of each such magnitude is plotted on a graph whose horizontal axis represents the current value and whose vertical axis represents the immediately preceding value. Points are produced lying in regions away from the diagonal and from the axes. If the detected waveform originates from a regularly varying interfering source, the corresponding points will lie on or near the diagonal. If the interfering source is a waveform undergoing step changes, the corresponding points will lie adjacent to the axes. In this way, discrimination between flames and interfering sources of radiation can be made.

Abstract: A probe (10) employs a scintillator (18) as a detector for high-energy beam dosimetry. The scintillator (18) is positioned in an ionizing radiation beam (52) which creates a light output that is proportional to the radiation dose-rate incident upon the scintillator (18). The light is conducted from the scintillator (18) through a light pipe (16) to a photomultiplier tube (28), which converts the light to an electric current. The scintillator (18), the light pipe (16), the photomultiplier (28), and associated optical connections have opaque coverings or sheaths to prevent extraneous light from being introduced into the probe (10). The electric current produced by the photomultiplier tube (28) is proportional to the radiation dose-rate incident upon the scintillator (18). The radiation dose-rate may then be displayed or recorded by a measurement of the electric current.

Abstract: A multi-element infrared detector for thermal imaging, wherein the detector includes a main substrate, an aperture plate and a plurality of detector elements formed on the main substrate and arranged thereon in an array. Each detector element having a photosensitive zone and output and common terminal electrodes formed at opposite ends thereof. The aperture plate having at least one aperture for restricting the field of view of the photosensitive zone. The detector includes an auxiliary electrode formed on the rear surface of the aperture plate in a position to contact the common terminal electrodes when the device is assembled. The infrared detector also includes a common metal line formed on the substrate in a position to interconnect a plurality of common terminal electrodes and the auxiliary electrode contacts the common metal line.

Abstract: The method and system interpretation for determining dose equivalents of a multi-element thermoluminescent dosimeter in mixed photon-beta and photon-neutron fields is described. The four TL Elements are covered by nearly tissue equivalent filters including only one metal filter which is used to provide low energy photon discrimination. In a mixed field, deep and shallow dose equivalents and the identity of the field's components are derived from the dosimeter's response in pure fields.

Abstract: Apparatus for radiographic imaging including a multistage avalanche chamber receiving radiation from a multiplicity of radiation point sources on a sample and providing a multiple photon output indicative of the path of the emitted radiation through the avalanche chamber, image intensification apparatus receiving the photon output of the avalanche chamber, a camera receiving an output from the image intensification apparatus; image processing apparatus for receiving the camera output and carrying out a vector analysis on the information contained in the camera output in order to determine the location of the radiation emitting point source on the sample.

Abstract: A pyroelectric film has a pattern of interconnected electrodes formed on one major surface, and a pattern of discrete electrodes and electrically conductive patches formed on the other major surface. The film 21 is supported by pillars connected to the patches, the pillars also producing a path for electrical signals between the patches and a signal processing means. Each discrete electrode is connected to a respective patch by a respective strip of electrically conductive material.

Abstract: Radiation imaging apparatus includes first and second bodies of material capable of producing scintillations in response to bombardment by ionizing radiation, each scintillation producing body having a surface bordered in part by an edge, the edge of the first body adjacent the edge of the second body. The radiation imaging apparatus also includes joining members located between the edges of the first and second bodies for transmitting light emitted from the edges of the first and second bodies as a result of scintillations produced by the first and second bodies, a collimator for collimating the ionizing radiation, and photomultiplier tubes for converting the scintillations to electrical outputs including a plurality of scintillation sensing units on the first and second scintillation producing bodies and on the joining body.

Abstract: Residual core material can be detected inside hollow cast articles using positron emission tomography. Positron radio-isotope material is inducted into any residual core material present by immersing a cast article in an aqueous solution of radio-isotope emitter, for example gallium. Absorbed gallium subsequently emits positrons which are annihilated in collisions with electrons emitting two 511 KeV gamma rays in diametrically opposite directions. The emissions are detected and tracked by a PET camera and the resulting images correlated with a sectioned image of the article as a check on the location of detected core material. Initially a low-dose-rate solution for the purpose of merely establishing the presence of core material is used but a second optional process step introduces a more active solution allowing a PET camera to collect sufficient data to image absorbed isotope.

Abstract: Measuring system constituted by a radiation detection circuit (3) welded to a reading circuit (2) by metal members (4), which is itself welded to a grooved cover (9) by other metal members (19). The cover (9) is placed on a cryostat cold finger (1) and a cavity (6, 10) contains the two circuits (2, 3). This arrangement obviates the need for bonding and welding electrical connection wires and therefore simplifies assembly, alignment and parallelism of the different parts.

Abstract: A method for porosity determination in porous media such as earth and rock core samples by x-ray computed tomography in which a sample of the porous medium is scanned after saturation with a first reference fluid and then after saturation with a second reference fluid to determine the linear attenuation coefficients of the sample saturated with the respective fluids. The method includes determining the linear attenuation coefficients of the respective fluids and comparing the difference in the attenuation coefficient of the respective fluids and the attenuation coefficient of the samples as saturated with the fluids to determine the porosity of the porous medium. The respective fluids may be a gas and a liquid wherein the x-ray absorption of the two fluids is significantly different. The fluids may be different liquids or a single gas at different pressure conditions to obtain the different absorption characteristics.