Abstract: A device locating radiation sources includes a pinhole camera, a collimator means for closing off or obturating the camera, a luminescent or phosphor screen, and a camera optically coupled to the screen. The collimator comprises two half-collimators rotatable about a common rotation axis (AA').

Abstract: A testing apparatus for the calibration of overheating or rail brake locating devices comprises an IR emitter which is guided in a housing so that it can shift along a curved track to exhibit an appropriately adapted beaming direction in a particular position. An extension piece for the track is provided for further changing the beaming direction.

Abstract: A method of quantitative analysis of free organic components in a drilling fluid comprising separating solid and liquid components of the drilling fluid using a non-filtering technique such as centrifuging, mixing a sample of the liquid components with a solution of an inorganic carrier such as 2M KBr and analyzing the mixture using infrared spectroscopy so as to determine the amount of organic components in the mixture and deriving the amount of free organic components in the drilling fluid from this analysis. In one embodiment, the mixture is dried to leave a solid mixture of the organic components and the carrier. In this case, the sample is preferably analyzed using a reflectance technique such as diffuse reflectance infrared spectroscopy. In another embodiment, the mixture is analyzed as a liquid, preferably using a direct transmission technique. In both the liquid and solid cases, Fourier transform infrared spectroscopy is preferred.

Abstract: A nuclear medicine diagnostic imaging system wherein the gamma camera rotates about the patient and is coupled to receive electrical power, control signals and to transmit data using cableless coupling means. This enables the system to provide whole body helical scans. Reconstruction begins during the first revolution of the camera about the patient and continues during subsequent revolutions to provide evolving images.

Abstract: An assembly for mounting a focal plane array. The assembly includes a fixture of thermally conductive material having a first substantially planar surface and a second surface. The fixture is attached to the focal plane array at the first surface and to a frame of a housing at the second surface thereof. In a specific embodiment, the assembly further includes a mechanism for aligning the fixture, with the attached array, to the frame and at least one flexible connector for electrically connecting the focal plane array to a circuit board disposed within the housing. In the illustrative embodiment, the alignment mechanism includes a clocking slot in the second surface of the fixture which is adapted to engage a protrusion on the frame.

Abstract: A micro-bolometric infrared (IR) staring array is described. The active element in each pixel within a two-dimensional array is a device having a selectively forward-biased p-n junction, e.g. a selectively biased diode. Each diode in the array serves as both an IR energy detecting element and a switching element. Each diode in a given row of the IR pixel array to be sensed, or read, is driven at a constant voltage, rendering its IR response highly controllable in the forward biased operating curve of the diodes in the addressed row. Diodes not being driven are, due to their reverse bias, in their off state producing minute leakage current and thus make no significant contribution to the sensed current representing a given pixel's IR exposure. The row-addressed driven or active diodes are sensed column by column by sample and hold techniques to produce a two-dimensional IR pixel image of a target.

Abstract: A crystal assembly for optical analyzation of samples includes a first crystal member and a second crystal member, the latter of which is preferably a diamond. The first and second crystal members, which have substantially the same index of refraction for infrared energy, are coupled together at an optically transmitting interface. This interface may be formed by crystal surfaces in intimate contact with one another or by a third crystal member positioned therebetween. The first crystal member has at least one circumferential sidewall focusing surface for redirecting infrared energy within the first crystal member to and from a focal ring or focal plane at or near the optical interface. The focused infrared energy transmitted from the first crystal member is internally reflected within the second crystal member to obtain encoding specific to a sample in contact with a surface of the second crystal member.

Abstract: A SPECT camera system has detector heads (14a, 14b, 14c) each having a collimator (18) facing toward an examination region (10). The detectors receive emission radiation from a radioisotope injected into a subject in the examination region and, preferably, also receive transmission radiation from a transmission source (20) disposed across the examination region. The detectors rotate around the subject through a plurality of projection angles. The detectors generate projection views from the received radiation for each projection angle. The projection views are stored in a projection view memory (26). A reconstruction processor (38) reconstructs the projection views into a volumetric image representation that is stored in a volumetric image memory (40). A reprojector (42) reprojects the volumetric image and volume of interest along each projection angle producing a set of reprojection views and regions of interest.

Abstract: An alpha continuous air monitor (CAM) with two silicon alpha detectors and three sample collection filters is described. This alpha CAM design provides continuous sampling and also measures the cumulative transuranic (TRU), i.e., plutonium and americium, activity on the filter, and thus provides a more accurate measurement of airborne TRU concentrations than can be accomplished using a single fixed sample collection filter and a single silicon alpha detector.

Abstract: A method for determining the downhole flow regime in a horizontal well borehole traversing a subterranean formation. A first gas holdup value within the borehole is measured using a fluid density tool. A second gas holdup value within the borehole is measured using a fullbore gas-holdup tool. The downhole flow regime is then determined as a function of the first gas holdup value and the second gas holdup value. A downhole flow regime comprised of dispersed bubble flow is indicated where the first gas holdup value is approximately equal to the second gas holdup value. A downhole flow regime comprised of annular flow is indicated where the first gas holdup value is substantially greater than the second gas holdup value and the velocity of the gas phase is substantially greater than the liquid phase. A downhole flow regime comprised of stratified flow is indicated where the first gas holdup value is less than or greater than the second gas holdup value.

Abstract: An apparatus comprises a fiber optic device having a plurality of cores buried in a cladding, a first luminescent screen fixed to an input face of said fiber optic device, and a first CCD image sensor fixed to an output face of the fiber optic device. The CCD image sensor comprises a package, a CCD chip fixed in the package, lead pins penetrating said package, and bonding wires connecting said lead pins to said CCD chip. The CCD chip comprises an image pickup region for converting a ray incident thereto into an electric signal, and bonding pads in contact with said bonding wires and wherein said output face is in contact with said image pickup region and said output face is not in contact with said bonding pads.

Abstract: Disclosed is an improvement of a method for erasing a radiation image remaining in a stimulable phosphor sheet which has stored a radiation image and has been irradiated with stimulating rays to read the radiation image. The improvement comprises a first erasing step of irradiating the phosphor sheet with a first erasing light containing a light portion of wavelength in ultraviolet region; and a second erasing step of irradiating the phosphor sheet with a second erasing light containing no light portion of wavelength in ultraviolet region, said second erasing light and said first erasing light being employed in a ratio of amount of light in the range of 15/85 to 45/55. Devices for erasing radiation image appropriately employable in the above-mentioned method are also disclosed.

Abstract: Nondestructive methods and apparatus for determining a concentration of interstitial oxygen in a generally cylindrical body of crystalline silicon. The invention transmits an infrared (IR) beam through the body generally transverse to a longitudinal axis of the body and measures the absorption coefficient of an interstitial oxygen absorption band at a wavenumber W.sub.p of approximately 1720 cm.sup.-1. Further, the invention determines the concentration of interstitial oxygen in the body as a function of the measured absorption coefficient.

Abstract: To calibrate a nuclear camera, the scintillation crystal (10) is irradiated with a uniform flood source (34). Scintillation events cause corresponding electrical pulses from photomultiplier tubes (12) that are optically coupled to the scintillation crystal. A selection circuit (40) compares (42) the amplitude or energy of pulses at each coordinate with a median energy and divides the pulses to generate a higher energy image (44) and a lower energy image (46). When the higher and lower energy images are subtracted (50) regions of the difference image (52) with high count densities identify a photomultiplier tube for gain adjustment. A gain adjustment circuit (60) monitors the amplitude of the electrical pulses and the number of pulses with each amplitude from the selected photomultiplier tube to generate a raw data energy distribution curve (FIG. 3). The energy distribution curve is smoothed (70) and the first derivative is taken (72). The curve is filtered (74) to isolate a preselected energy region.

Abstract: A detector having a plurality of densely packed x-ray detectors arranged into an array. Each detector preferably includes a scintillator element which is optically coupled to a photodetector element, preferably with a fiber optic link. Each photodetector element is preferably optically separate from adjacent photodetector elements. The detector array preferably includes integral an alignment structure to align the scintillator elements with the photodetector elements. The scintillator array elements are preferably formed from materials which possess a fast response and a minimum afterglow time.

Abstract: A monolithically constructed infrared, tunable Fabry-Perot cavity filter-detector for spectroscopic detection of particular substances having an absorption line in the wavelength range from 2 to 12 microns. The filter-detector has a hermetically sealed Fabry-Perot cavity that has a mirror which has an adjustable distance relative to another mirror of the cavity. The former mirror is adjusted by piezoelectric film on the mirror support or with piezoelectric stacks or wall supporting the mirror. There may be electrodes situated near the mirrors for capacitive sensing of the distance between the mirrors. Light to be filtered and detected comes in through a window wafer which may have diffractive or refractive microlenses, plus an optional spatial filter. After passing through the window wafer, the light is filtered by the tunable mirrors of the Fabry-Perot cavity. The portion of the light that is passed by the cavity is detected by an infrared microbolometer or a CCD array.

Abstract: A control circuit for a scintillation camera is provided in which only discrete scintillation events are processed. When a scintillation event arrives, all light intensity signals below a predetermined threshold, indicating that the signals below the thresholds are not likely to be involved in the event, are blocked from the sum signal. The valid event discrimination circuit disclosed considers the sum signal of light intensity signals originating from only those photodetectors whose output signals are above the threshold. Valid event discrimination is not adversely affected by signals coming from photodetectors not involved in the event after the threshold detection takes place.

Abstract: A stimulable phosphor sheet, on which a radiation image has been stored, is exposed to stimulating rays, which cause it to emit light in proportion to the amount of energy stored thereon during its exposure to radiation. The light emitted by the front surface of the stimulable phosphor sheet and the light emitted by the back surface of the stimulable phosphor sheet, are detected photoelectrically. The image signal components of the two image signals are subtracted from each other, which represent corresponding picture elements on the front and back surfaces of the stimulable phosphor sheet, difference values being thereby obtained. A judgment is made as to whether each of the difference values falls or does not fall within a predetermined range. In cases where a difference value is judged as being outside the predetermined range, it is determined that an abnormal signal component is contained in at least either one of the two image signals.

Abstract: A highly uniform infrared illumination source for illuminating a stripe of a moving sensitized web for line scan imaging of imperfections in the coating on the web by a CCD imaging camera. A light integrator having an elongated housing formed with side and end walls defines a linear light integrating cavity having diffusely reflecting interior wall surfaces. An elongated array of infrared LEDs is spaced along the side wall for emitting light into the cavity for integration within the cavity. A longitudinally extending slit is formed in the side wall through which a diffuse, linear light beam exits the elongated slit having a varying longitudinal intensity profile. The intensity of the light emitted by the LEDs is modulated in an intensity pattern that alters the varying longitudinal intensity profile of the linear light beam to provide a desired longitudinal intensity profile of the stripe of diffuse illumination.

Abstract: A probe device for in-situ detection of contaminants such as petroleum prcts in a subsurface media such as soil. The device comprises an elongated probe housing which is driven into the media. An ultraviolet lamp located in the housing provides excitation energy which is reflected through a UV transparent window in the housing to the media by at least one reflecting element in the housing. The reflecting element allows longitudinal offset of the lamp from the window providing space for high intensity UV lamps. A radiation receiver receives fluorescent radiation emitted from contaminants in the media transmitted through the window and provides a signal for analysis equipment on the surface. A concentrating reflector between the lamp and the housing and a focusing lens between the lamp and the reflecting element collect and focus excitation energy from the lamp.