Abstract: There is provided a sample holder for use in radiant spectroscopy analysis. The sample holder comprises a plurality of openings defined by one or more solid, substantially opaque, structural elements, each of the openings being arranged to retain a solid, semi-solid, gel or liquid material sample in the opening. Desirably, the openings constitute at least a major portion of the combined area of the one or more structural elements and the openings. In one embodiment, the sample holder comprises a plurality of strips secured together at irregular (random) or regular intervals. Desirably, one first group of strips is disposed in parallel spaced apart relation and a second group of strips disposed in parallel relation with the groups intersecting at an angle of between 30 and 150 degrees and secured together at substantially regular intervals. The strips may be woven as in wire mesh, or non-woven as in expanded metal. In another embodiment, the sample holder is a sheet of metal having perforations.

Abstract: A cassette for a photo-stimulable luminescence (PSL) radiography which comprises a flat rigid base having one surface of which a layer of PSL material is adapted to be supported, a cover for the flat base constituted of a top wall coextensive in area with the one surface of the flat base and a flange extending around the periphery of the cover top wall and projecting at an angle to the cover top wall, the peripheral flange of the wall being disposed in close-fitting relation to side edges of the base when the base and cover are assembled, and cooperating releasable detent means on the peripheral flange of the cover and the side edges of the base for securing the cover and base together, the cover being separable from the base upon release of the detent means to permit the base for radiographic exposure of the PSL layer.

Abstract: A system and method for using the detector to differentiate neutron attenuating material from high x-ray attenuating material in an object. The inspection system is used to detect the presence of nitride in titanium sponge nuggets or residual core material in a hollow-cast turbine engine blades. The inspection system uses a dual radiation source to alternately emit neutrons and x-rays or gamma rays at the object under inspection. A dual modality gas ionization detector detects the radiation passing through the object and sends the detected radiation to a processing means for image generation. The generated image is displayed on a display, enabling objects formed with low and high attenuating material to be distinguished.

Abstract: A three head SPECT camera system has three detector heads (22a, 22b, 22c) disposed at 120.degree. intervals. Two of the detector heads have collimators (40a, 40b) which have a first set of vanes (42a, 42b) extending in a direction parallel to an axis of rotation (26) but which are canted 15.degree. relative to a perpendicular, central axis (32a, 32b) of the respective detector heads. A second set of vanes (46a, 46b) extend perpendicular to the 15.degree. tipped set of vanes to define a rectangular grid. When the second set of vanes is perpendicular to the detector heads, the first detector head is constrained to receive radiation along a first plurality of parallel rays (44a) and the second radiation detector head is constrained to receive radiation along a second plurality of parallel rays (44b). The collimators are mounted to the detector head such that the first and second parallel rays (44a, 44b) are perpendicular to each other. In this manner, a full 180.degree.

Abstract: A logging-while-drilling apparatus includes a source of exciting radiation, means for illuminating the borehole wall with the radiation and means for detecting radiation returning from the borehole resulting from illumination with the exciting radiation. A bottom hole assembly (BHA) incorporating such apparatus can comprise a drill bit, one or more stabilizers and one or more drill collars and the source and illuminating and detecting means can be located in one of these or distributed therebetween according to requirements. A window can be provided to allow illumination of the borehole and detection of returning radiation.

Abstract: Detectors for ionizing radiation (X-rays, gamma rays, electrons, protons, alpha particles, etc. as well as neutrons) of the gas proportional scintillation counter type using techniques to compensate for a loss of scintillation light reaching the photosensor due to solid angle and reflection effects. Two such techniques are disclosed. One technique involves the use of two non-parallel electrically charged grids which produce a radially increasing electric field, thus radially increasing the intensity of the scintillation light. Another technique involves the use of a mask of small opaque dots having a radially decreasing density covering the photosensor, thus radially increasing the intensity of the scintillation light transmitted to the photosensor. The preferred embodiment for X-ray detection consists in a detector, filled with very pure xenon at atmospheric pressure, with a 2.5 cm diameter radiation window (1), a grid with a spherical (2 cm radius) curvature (2) with its edges placed 0.

Abstract: An invention is described which uses quenchable phosphors to achieve a novel emission response in intensifying screens. The quenchable phosphor has the characteristic of reducing its efficiency of converting incident x-ray, gamma ray, or ionizing particulate radiations into emitted radiation in the ultraviolet (UV), visible or infrared (IR) regions of the electromagnetic spectrum when being essentially simultaneously irradiated by a spectrum of radiation of a specific range in the UV to visible to IR spectrum. The quenchable phosphor is combined with another class of phosphor, which emits the spectrum of radiation when struck by ionizing radiation which is similar or identical to the quenching radiation of the quenchable phosphor. These phosphors can be combined in a variety of geometrical manners, both homogeneously and heterogeneously, to achieve extended dynamic range and spatial frequency filtering for radiographic imaging systems.

Abstract: An improved phoswich radiation detector used pure CsI crystal and a fast plastic scintillator and a single photomultiplier tube. The plastic is arranged to receive incident radiation, and that which passed through then strikes the CsI crystal. Scintillation light from both the plastic and CsI crystal are applied to the photomultiplier tube, with the light from the plastic passing through the crystal without absorption therein. Electronics are provided for analyzing the output of the photomultiplier tube to discriminate responses due to the plastic and the CsI crystal, through short gate and long gate integration, to produce results which are indicative of the characteristics of the different types of incident radiation, even in the presence of large amounts of radiation. The phoswich detector has excellent timing resolution. The scintillators of the CsI- phoswich were chosen for their fast risetimes, of about 3 ns for NE102A, and 30 ns for the pure CsI.

Abstract: A staring infrared microscope which includes optics for focusing a magnified image of an object onto a 2D array detector of IR sensitive elements, a processor for processing the information received from the 2D array detector, including controlling the integration time of the 2D array detector as a function of the magnification of the object to generate a thermal descriptive image of object, and a display for displaying the thermal descriptive image. Also disclosed is a scanning infrared microscope which includes optics for focusing a magnified image of an object onto a linear array detector of IR sensitive elements including a scanning mirror for scanning the object and a processor for processing the information received from the linear array detector to generate a thermal descriptive image of object. The scanning infrared microscope further includes an output display for displaying the thermal descriptive image.

Abstract: The photometer of the present invention includes an optical system in which an emission beam generated by pulsed ultra violet radiation from a source is split into a sample beam and a reference interference beam by spectrally selective mirrors arranged in series. These mirrors reflect a beam having a wavelength range corresponding to an absorption wavelength of the gas to be detected onto one solid state detector and to pass a beam to a second spectrally selective mirror where a beam having second range of wave lengths corresponding to an interfering gas is reflected onto a second solid state detector. This second beam serves to measure the interfering gas and also as an imperfect reference channel. In a preferred embodiment the radiation from the source is split prior to entering the sample cell.

Abstract: An X-ray collimator is provided to permit diagnostic medical imaging of two or more radioactive isotopes emitting spectrically close gamma rays. The collimator includes a filter plate at one or both ends of the collimator's tubular passageways with the filter plate having a plurality of openings extending therethrough which are aligned and coincident with the tubular passageways. The openings in the filter provide a thin filtering edge adjacent the collimator passageway ends which interact with and remove substantially most of the unwanted secondary and scattered radiation produced by photons striking septa within the collimator's passageways.

Abstract: The observation was made that virtually all octane number variations arise from 23 components present in a broad variety of gasolines. Consequently it is possible to develop a calibration set consisting of a gasoline base stock as modified by one or more of the 23 components. By measuring the octane number and near infrared spectrum of each member of the calibration set, the octane number of any sample at the site specific for the base stock may be determined from the near infrared spectrum of the sample.

Abstract: A fluorescence detection apparatus for differentiating an object containing a fluorescent substance by detecting fluorescence emitted by the fluorescent substance, which apparatus includes: an excitation light source which emits ultraviolet light that excites a fluorescent substance; a light detector for detecting fluorescence; and an optical guiding system consisting essentially of a single glass block of an angular columnar shape having: an incidence face located on a side of the glass block, through which the ultraviolet light enters; a reflection and emission face constituted by an inclined face, from which the incident ultraviolet light reflects toward the object, and through which florescence emitted from the object passes toward the light detector; and a detection face at the bottom of the glass block facing the object, through which the ultraviolet light exits and hits the object, and through which florescence emitted from the object enters, thereby allowing for reduction in the size of the apparatus,

Abstract: A thermal imaging system (10) contains a focal plane array (30) including a plurality of thermal sensors (32) mounted on a substrate (62). Each thermal sensor (32) includes a film layer (34) of infrared sensitive material which is both electronically and thermally isolated from the associated integrated circuit substrate (62). An image may be formed on the film layer (34) in response to infrared radiation from a scene (12). Electromagnetic radiation (22) from a source (visible light or near infrared) (20) is used to reproduce or transfer the image from the thermal sensors (32) onto the first surface (68) of the substrate (62). A thermoelectric cooler/heater (66) may be provided to optimally adjust the temperature of the substrate (62) to improve overall image quality.

Abstract: An improved modular FLIR system is provided that fits in the same space elopes that were provided for the Army's GEN I FLIR's. The resolution is more than doubled by using a narrow two dimensional array of Hg-Cd-Te detectors with pn junctions as a time-delay-integration line sensor, improved optics and analog-digital conversion with image enhancement.

Abstract: A solid state image sensor CCD array (10a) has a two block, full-frame, parallel-register structure. The two blocks of the array, each comprised of photosensitive radiation sensors or pixels (20), feed into a single centrally disposed serial read-out register (10b) so as to form one unified photosensitive domain. The read-out register is photosensitive except for two associated narrow clock buses (H1, H2) that are spaced apart so as to only block a minimum of input radiation in any one pixel (22) of the read-out register. Each stage of the read-out register can act as a pixel that is approximately square and that is approximately the same size as the pixels of the two full-frame blocks. In operation, the centrally disposed read-out register can be stationary for a significant first portion of a total frame time (integration period), and then in a latter part of the frame time it can be read out one or more times to provide exposure update information for all of the pixels of the array.

Abstract: A system and method for conditioning a photoconductive radiation detector achieve charge redistribution within a photoconductive layer without the need for charge removal or charge injection techniques. A first conditioning voltage is applied across the detector to establish a first electric field. The first electric field is reversed relative to fields applied to the detector during image exposure and image read-out operations. While the first conditioning voltage is maintained, the photoconductive layer is exposed for a period of time to first conditioning radiation having one or more wavelengths selected to penetrate at least a portion of the photoconductive layer. A second conditioning voltage, less than the first conditioning voltage, then can be optionally applied across the detector to establish a forward bias electric field. While the second conditioning voltage is maintained, the photoconductive layer is exposed for a period of time to second, broad spectrum conditioning radiation.

Abstract: A dual entrance window ion chamber is provided for purposes of measuring x-ray exposure. The ion chamber includes a housing having a cavity formed therein and which defines an ion chamber. The housing has oppositely disposed first and second openings therein located on opposite sides of the chamber. First and second x-ray entrance windows respectively cover the first and second openings for permitting entrance of x-rays into the chamber. A collector is located in the chamber intermediate the first and second windows for collection of electrons for use in measuring x-ray exposure. The first and second windows are constructed differently from each other such that the first window is optimized so that the ion chamber provides a relatively flat energy response to x-rays over a first x-ray energy range. The second window is optimized so that the ion chamber provides a relatively flat energy response over a second x-ray energy range.

Abstract: A method and apparatus are provided for determining the number of photons in a single-mode, coherent microwave field. A plurality of Rydberg atoms are generated whereby each Rydberg atom has an energy state defined by a plurality of energy levels. The Rydberg atoms are passed through the microwave field one at a time. An exit state of the microwave field in terms of phase is measured as each Rydberg atom exits the microwave field. An exit energy level of each Rydberg atom exiting the microwave field is also detected. The number of Rydberg atoms exiting the microwave field in each of four measurement classes defined by the exit state and exit energy level are counted.

Abstract: A new set of mid-Infrared transparent elements with different geometries to enable examination of the sample surfaces by Internal Reflectance Micro Infrared Spectroscopy is disclosed. The Infrared beam from the IR microscope, either collimated or focused, enters the surface of the element and impinges on an inclined surface of contact between the sample and the element at an angle above the critical angle. This IR beam from the microscope operating in the reflectance mode is then internally reflected at the beveled surface cut at a selected angle, travels inside the IR element, reaches a circular reflector surface where it is reflected back to retrace its initial path. The beam once again comes in contact with the sample at the sample and the element interface and is reflected.