Abstract: A radiation detector suitable for use in tomographic scanners comprising at least one cadmium tungstate scintillation crystal optically coupled with a silicon photodiode or other photoelectric transducers. A plurality of cadmium tungstate crystals may be coupled to one silicon photodiode with fiber optic light guides. In a tomographic scanner, radiation passing through the scan circle impinges on the cadmium tungstate crystals causing them to scintillate. The light scintillated strikes the area of the p-n junction of the photodiode causing the photoelectric effect to be manifested. The intensity of radiation striking the crystal is determined by measuring the photoconductive conductance, photoemissive current or photovoltaic potential. From these intensities an image is computed of the radiation attenuation in the examined scan circle.

Abstract: The radiodiagnosis apparatus comprises intensifying screens required for radiography and has such structure that the screens and their supports ca be very easily removed for radioscopy.The radiodiagnosis apparatus according to the invention comprises an exposure device, including a frame (7) fixed to the radiodiagnosis apparatus in the exposure portion thereof and a removable drawer (8) supporting the intensifying screens sliding in this frame.Application to radiodiagnosis apparatus utilizable alternately in radiography and radioscopy.

Abstract: An X-ray detector for obtaining time resolved signals from intense pulsed X-ray sources, such as from a fuel pellet during a laser fusion process. The detector has a cathode which emits electrons when bombarded by X-rays from the fuel pellet. The electrons are accelerated by an electron accelerator to relativistic velocities and impinge on a Cherenkov emitter which radiates light. An optical system collects and focuses the radiated light onto an image converter streak camera or other fast photodetector to provide a trace of the light intensity as a function of time. Time resolved images of the fuel pellet may be produced by the detector and recorded by an image converter streak camera or by a camera using an optical Kerr cell shutter.

Abstract: A method of constructing arrays of collimators and/or detectors for penetrating radiation is described. A tape or foil is wound alternatively over and under rods provided in upper and lower sets to define a plurality of substantially parallel or slightly inclined channels for the radiation. The channels can be filled with suitable plastics material.

Abstract: Disclosed is a composite collector and concentrator structure comprising a laminate having a self-supporting layer of solid light transmitting material of extended area in one plane in optical contact with a relatively thin layer of a silicone resin derived from a trifunctional silane containing at least one species of luminescent material which absorbs electromagnetic radiation and emits electromagnetic radiation of a longer wave length. Use with photovoltaic solar cells is also disclosed.

Abstract: An X-ray detecting system includes a number of X-ray detectors mounted on the periphery of a vertical ring rotatable about a patient to be scanned diametrically opposite from an X-ray tube, slit collimator and chopper wheel mounted on the ring. Each detector includes a scintillator crystal typically of NaI, a photomultiplier tube that receives light from the crystal proportional to the incident X-rays, an amplifier energized by the output of the photomultiplier tube that provides a proportional signal to an LED that energizes both the photomultiplier tube (PMT) to provide light feedback and a photodiode that provides an electrical output signal so that the total current at the PMT anode resulting from X-ray light and LED light is constant. Circuitry is preferably included so that the LED supplies only the chopped part of the X-ray equivalent light signal with practically no d-c component.

Abstract: A unique scintillation detector unit is disclosed which employs a special light transfer and reflector means that encases and protects the scintillator crystal against high g forces. The light transfer means commprises a flexible silicone rubber optical material bonded between the crystal and the optical window and having an axial thickness sufficient to allow the scintillator to move axially inside the container under high g forces without destroying the bonds. The reflector means comprises a soft elastic silicone rubber sleeve having a multiplicity of closely arranged tapered protrusions radiating toward and engaging the periphery of the scintillator crystal to cushion shocks effectively and having a reflective material, such as aluminum oxide powder, in the spaces between the protrusions. The reflector means provides improved shock absorption because of the uniform support and cushioning action of the protrusions and also provides the detector with high efficiency.

Abstract: A method and apparatus for the quantitative and qualitative analysis of the elemental composition of materials in concentrations as low as a few atoms, or molecules, per cubic centimeter. When introduced into a gas stream containing an excess of an energetic metastable species of nitrogen or noble gas, the material, if atomic, is rapidly and repeatedly excited, or, if molecular, it is decomposed and subsequently certain component atoms of the molecule are excited, and thereupon fluoresce at their characteristic wavelength(s). The wavelength(s) and intensity of the emitted light (fluorescence) are determinative respectively of the identity and the concentration of the atoms of the different elements present.

Abstract: Apparatus for concentrating radiant energy such as solar radiation, collected over a large area, to a smaller area for more efficient conversion of the radiant energy to a more useful form of energy. Fluorescent material in a thin film form is optically bonded by an adhesive or viscous, transparent medium to a massive slab of transparent material such as glass or plastic. Energy conversion devices, such as photovoltaic cells, are disposed around the edges of the slab.

Abstract: A scintillator for a gamma ray camera constituted by a crystal of NaI (Tl) having a surface roughness of less than 400 grit and a thickness of less than approximately 9 mm.

Abstract: A gamma radiation detector, wherein it comprises a xenon crystal, a xenon atmosphere above said xenon crystal, a pair of electrodes comprising two metallic electrodes on either side of the xenon crystal, the first electrode being brought to negative potential (cathode) and located in the vicinity of one face of the xenon crystal and the second electrode brought to positive potential (anode) is placed parallel to the cathode in the xenon atmosphere and visualization device of the photons emitted in the gaseous xenon, whereby the face of the xenon crystal in the vicinity of the cathode is arranged in such a way that it receives the gamma radiation to be measured.

Abstract: A typical embodiment of the invention detects leaking fuel rods by means of a radiation detector that measures the concentration of xenon-133 (Xe.sup.133) within each individual rod. A collimated detector that provides signals related to the energy of incident radiation is aligned with one of the ends of a fuel rod. A statistically significant sample of the gamma radiation (.gamma.-rays) that characterize Xe.sup.133 is accumulated through the detector. The data so accumulated indicates the presence of a concentration of Xe.sup.133 appropriate to a sound fuel rod, or a significantly different concentration that reflects a leaking fuel rod.BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates to inspection techniques, and more particularly, to a radiation detection method and apparatus for identifying leaking fuel rods within a nuclear reactor core, and the like.2.

Abstract: A small but very efficient X-ray detector operating in a current integrating mode for use in high speed tomography apparatus comprises a scintillator that is entirely coated with a highly reflective matte material except for a relatively small-area window. A P.I.N photo-diode is juxtaposed with the scintillator opposite the window and the two are secured together at an optical interface comprising a transparent adherent material preferably having an index of refraction between the indices of the scintillator and the photo-diode. The ratio of the active surface area of the photo-diode to the area of the scintillator coated with reflective material is appreciably less than unity.

Abstract: A method and an instrument are, herein, disclosed for measuring the absorbed dose rate of beta-ray in sites of the human body. The instrument of this invention consists of a thin scintillator, a linear amplifier, a pulse selector having disposed in parallel therein a plurality of pulse height selection mechanisms for selectively setting the lower and upper limits of pulse height discrimination according to an epidermal thickness of human tissue, and a dose rate indicator. The method and the apparatus of this invention are characterized by making the relationship between the counting rate per fluence rate and the maximum energy of beta-ray equal to the relationship between the absorbed dose rate per fluence rate and the maximum energy of beta-ray, and therefore, the absorbed dose rate can be measured independent of the energy of beta-ray.

Abstract: A scintillator for a gamma ray camera includes a pair of crystals mechanically pressed together. The surfaces of the crystals are roughened so as to form a photo-diffuser for the light generated as a result of scintillation.

Abstract: A scintillation detector assembly is described which employs a scintillation phosphor such as a thallium activated sodium iodide crystal, wherein a blind hole is machined in the crystal to improve the efficiency of measuring the degradation rate of a radioactive material placed therein. The performance of the assembly is defined by the energy resolution of the radiation emanating from the radioactive source. This performance is improved by balancing the collection of light from areas of low and high light collection. This is achieved by suitably preparing the surfaces of the crystal and by controlling the reflectivity of these surfaces using controlled and fixed reflectivity material such as optical filters, cellulose ester-type fibrous paper and like materials. Improvements in resolution of 30 - 50% over prior art well assemblies have been measured for radioactive sources such as .sup.129 I.sub.53.

Abstract: A plurality of independent scintillators are used to measure radiation dose rate. The opening of a light shielding shutter locating the scintillators and a photomultiplier is adjusted to maintain linear proportional relationship between the counting rate and the dose rate.

Abstract: In order to avoid losses in definition and contrast which are observed in image-converter tubes as a consequence of the light scatter taking place within the body of the scintillators of the input screens of these tubes, when said scintillators occur in the form of a continuous layer of material, the present invention provides for the formation within a layer of microscopic channels which are transversely disposed, the channels being formed by covering the substrate, prior to the deposition of the scintillator thereon, with a layer of a granular material, preferably glass balls. Application to radiology and scintillography.

Abstract: Method and apparatus for detecting and recording breast cancer, in which the breast is exposed to X-rays, preferably in the so-called soft range, the transmitted beam of rays is scanned by means of a moving, strip-shaped screen and the image of the strip-shaped screen is picked up with a television pickup tube moving along with the screen, and is displayed on a monitor tube.

Abstract: An improved apparatus for testing a sample by means of luminescent reaction to detect reactive materials therein. A ribbon of filter material, which may be translucent or opaque, is provided to filter the sample and to carry the residue to a reaction position. A translucent surface is provided to carry a reagent to the reaction position. Both surfaces are brought into mutual contact in the optical vicinity of a photodetector, which thereby detects the resulting luminescent reaction to provide an indication of the quantity of reactive material present in the sample. An improved pinion roller advances the ribbon of filter material in a reliable fashion. In an alternative embodiment, the ribbon of filter material is used without the translucent surface.

Abstract: A photodetector comprises an evacuated envelope with a transparent face plate. The face plate is selected from a material which causes total internal reflection of photons produced by Cerenkov radiation. In the evacuated envelope are an anode and a transmissive type photocathode. The photocathode is spaced apart from the face plate.

Abstract: A means and method of radioimmunoassay is disclosed whereby an insolubilized or solid phosphor and binding agent such as an antibody are associated by chemical or physical means to provide a solid scintillating immunoadsorbent cell. This cell is capable of selectively binding or retaining radioactive or labeled antigens and transmitting radioactive energy to a phosphor or photon emitting substance. The luminescence emitted by the phosphor is measured by a scintillator counter and is directly proportional to the radioactive energy released by the labeled antigen bound to the antibody. Upon completion of the measurement the labeled antigens are separated from the antibody and removed from the cell which may now be used for additional analysis. A convenient means for obtaining a solid phosphor and/or binding agent is to combine them by physical or chemical means or to shield one from the other by a separating barrier.

Abstract: A radiation detection system which utilizes the generation of Cerenkov light in and the transmission of that light longitudinally through fiber optic wave guides in order to transmit intelligence relating to the radiation to a remote location. The wave guides are aligned with respect to charged particle radiation so that the Cerenkov light, which is generated at an angle to the radiation, is accepted by the fiber for transmission therethrough. The Cerenkov radiation is detected, recorded, and analyzed at the other end of the fiber.