Abstract: A radiation detection device includes a scintillator having an upper scintillator body section and a lower scintillator body section. The upper section forms an arcuate-shaped cap through which the incident radiation enters the scintillator, and the lower section has sidewalls disposed at a selected taper angle with respect to the longitudinal axis of the scintillator body and an optically transmissive window disposed opposite the cap of the upper section such that optical photons can pass from the scintillator to a photodetector coupled to the window. An optically-diffuse reflective layer is disposed over the sidewalls and the cap. The sidewalls typically have a positive taper angle, being closer to one another near the optically transmissive window and farther from one another near the cap. The arcuate shape of the cap typically conforms to the arc of a circle centered on the optically transmissive window.

Abstract: Device for the real-time localization of radiation sources, comprising a pinhole chamber (4) whose walls form a shield, and, within the chamber and opposite the pinhole (16), a screen (28) which is transparent in the luminous range and capable of converting the source radiation into luminous radiation and of preventing the light in the area from reaching the screen while remaining transparent to the source radiation. A camera (30) is connected to the screen and provides an image of the sources in the form of electric signals, by virtue of the luminous radiation it receives from the screen, as well as an image of the area by virtue of the light it receives from this area through the screen when a shutter is open. The images can be superposed and can be made visible through signal processing and display.

Abstract: Method and apparatus for producing separated columns of scintillation layer material, for use in detection of X-rays and high energy charged particles with improved spatial resolution. A pattern of ridges or projections is formed on one surface of a substrate layer or in a thin polyimide layer, and the scintillation layer is grown at controlled temperature and growth rate on the ridge-containing material. The scintillation material preferentially forms cylinders or columns, separated by gaps conforming to the pattern of ridges, and these columns direct most of the light produced in the scintillation layer along individual columns for subsequent detection in a photodiode layer. The gaps may be filled with a light-absorbing material to further enhance the spatial resolution of the particle detector.

Abstract: The present invention is a scintillator which emits light in response to radiation. The scintillator is capable of being reversibly changed between solid and liquid phases, whichever is desired, by temperature control. The scintillator comprises a fluorescent substance for converting radiation energy into light energy; a solvent which transfers radiation energy to the fluorescent substance and dissolves and diffuses the fluorescent substance and a radioactive substance acting as an object of measurement to thereby homogenize them; and a fixing substance which enables the solvent, the fluorescent substance and the radioactive substance to be fixed in a solid state and also liquified upon heating, the fixing substance being capable of phase change reversibility.

Abstract: A scintillator assembly for use in the detection of alpha radiation includes a body of optically-transparent epoxy and an amount of phosphor particles embedded within the body adjacent one surface thereof. When making the body, the phosphor particles are mixed with the epoxy when in an uncured condition and permitted to settle to the bottom surface of a mold within which the epoxy/phosphor mixture is contained. When the mixture subsequently cures to form a hardened body, the one surface of the body which cured against the bottom surface of the mold is coated with a thin layer of opaque material for preventing ambient light form entering the body through the one surface. The layer of opaque material is thereafter coated with a layer of protective material to provide the assembly with a damage-resistant entrance window.

Abstract: A scintillation crystal module of the type having a crystal housed in a backcap which is closed off by a glass window and sealed by an internal seal located between the window and the backcap is modified to include an external seal. The external seal is of moisture-impervious material and is attached to the outer surface of the backcap and the window and bridges over the boundary therebetween. The external seal may be made of an epoxy polyamid or a blocked urethane epoxy copolymer. The outer surface of the module may be sandblasted before the external seal is attached to the module, as by casting the adhesive in a suitable mold.

Abstract: The invention relates to a composition for the volumetric generation of radiation, wherein a first substance functions as a source of exciting radiation, and a second substance interacts with the exciting radiation to provide a second radiation. The compositions comprise a porous substrate which is loaded with: a source of exciting radiation, a component capable of emitting radiation upon interaction with the exciting radiation, or both. Preferably, the composition is an aerogel substrate loaded with both a source of exciting radiation, such as tritium, and a component capable of interacting with the exciting radiation, e.g., a phosphor, to produce radiation of a second energy.

Abstract: A luminescent layer is exposed to X-rays or gamma rays and whose luminescence is converted into an electric signal by a photo-electric transducer. Sensitivity variations of the combination formed by the luminescent layer and the transducer are compensated for in that the luminescent layer is repeatedly exposed to an electric field, during which exposure the sensitivity of the luminescent layer and the transducer is measured and stored, a calibration factor of the measuring device is created and changed each time in dependence on the stored sensitivity.

Abstract: A radiation imager comprises a scintillator mated to a photodetector array. An enclosure ring is disposed around the outer sidewalls of the scintillator and an enclosure ring cover hermetically bonded to the ring extends across the scintillator to form a chamber sealably enclosing the scintillator. The enclosure ring cover is substantially impervious to moisture, is radiation transmissive, and minimizes scattering of light from the scintillator. The cover may be optically reflective or light absorptive. The chamber is evacuated to draw the cover in towards the photodetector array and thus to ensure close contact between the cover and the scintillator and between the scintillator and the photodetector array. Desiccant can be disposed in the chamber to provide additional protection against moisture absorption by the scintillator.

Abstract: The invention provides a scintillation detector for nuclear radiation which comprises a synthetic diamond having a nitrogen impurity concentration of 150 ppm or less. The detector has solvent (or oxides thereof) impurity concentrations of 1000 ppm or less, where the solvents are any of the following: Ni, Cu, Mn, Al or Cr, or combinations thereof. The detector has Fe and Co impurity concentrations of less than 10 ppm. A practical version of the detector includes an optical fibre and a photomultiplier tube, the optical fibre collecting light emitted by the diamond and channelling it to the photomultiplier tube.

Abstract: The invention relates to a composition for the volumetric generation of radiation, wherein a first substance functions as a source of exciting radiation, and a second substance interacts with the exciting radiation to provide a second radiation. The compositions comprise a porous substrate which is loaded with: a source of exciting radiation, a component capable of emitting radiation upon interaction with the exciting radiation, or both. In the composition, a composite is formed from a carrier material and at least one of the source of the exciting radiation or the component which is capable of interacting with the exciting radiation. The composite is then employed for loading a porous substrate, preferably an aerogel substrate.

Abstract: A detector assembly which is particularly well suited for detecting gamma rays in a formation density logging tool employs a sodium iodide crystal and glass phototube; and is housed in a novel mounting arrangement which provides appropriate gamma ray shielding as well as protection from shock and vibration. The actual crystal is mounted in a hermetically sealing housing. The outer configuration of the housing allows for rigid attachment to a magnetic shield. This shield provides magnetic protection for the phototube so as to avoid undesired disturbances in the tube output signal during operation. A layer of elastomeric material provided with voids for volumetric expansion is interposed between the crystal housing and the magnetic shield. An outer insulating tube is then ruggedly secured to one end of the mumetal shield by an adhesive.

Abstract: A skin equivalent structure is formed from an aluminized polyester window and a scintillator. The scintillator is chosen to scintillate at a wavelength different from that of most Cerenkov light. The scintillator light travels through a light pipe and one or more filters to a photomultiplier tube. Beta particles reaching the scintillator provide light that results in an electrical output from the tube that corresponds to the skin beta dose rate. The filters are chosen to remove the Cerenkov light. In addition, the light pipe may also be chosen to attenuate the Cerenkov light.

Abstract: The invention provides a process for loading an aerogel substrate with tritium and the resultant compositions. According to the process, an aerogel substrate is hydrolyzed so that surface OH groups are formed. The hydrolyzed aerogel is then subjected to tritium exchange employing, for example, a tritium-containing gas, whereby tritium atoms replace H atoms of surface OH groups. OH and/or CH groups of residual alcohol present in the aerogel may also undergo tritium exchange.

Abstract: A scintillation detector providing a photomultiplier tube mounting system capable of withstanding substantial vibration and the like without damage to the photomultiplier tube. The mounting system provides a resonant frequency substantially above the frequency of the vibration normally encountered to prevent amplification of the vibration. The photomultiplier tube is mounted within a support tube with a thin layer of elastomeric material. The support tube is in turn mounted in a light-tight tube by spaced elastomeric rings having a relatively high spring rate. The support tube is provided with openings which render the support tube radially resilient so that thermal expansion of the elastomeric material between the support tube and the photomultiplier tube does not result in high compressive loads on such tube. Further, the elastomeric material can elastically flow into the openings in the support tube to relieve compressive stresses which would otherwise occur.

Abstract: By a radiation detector comprising a photomultiplier tube, a Bi.sub.4 Ge.sub.3 O.sub.12 crystal of which a face contacted to the photomultiplier tube and reflecting layers which essentially consisting of reflecting powdery agent and an acrylic resin type binder provided on faces other than the face of the crystal, the energy resolution can be made smaller and stable. Thus, the resolution of the detector can be made higher. The detection accuracy can be improved since the energy resolution caused to be reduced and stabilized by raising the thickness of reflecting layers up to 50 .mu.m or more. Furthermore use of an acrylic resin, as a binder for forming the reflecting layers, is effective in eliminating the influence of the silicone-based adhesive agent, which allows to enhance the reflectance and adhesion of the reflecting layers. At the same time, a processing once suffices to build the reflecting layers thus resolving the problem of intricate manufacturing.

Abstract: Selected scintillator materials provided in transparent block form for use in systems such as CT scanning systems employ a garnet host material for an activator ion which provides the desired luminescence. The garnet host material preferably includes gadolinium as one of its components in order to provide a transparent host material in bar form which has a high x-ray stopping power (where the radiation to be detected is x-ray radiation). Chromium, cerium and neodymium are preferred activator materials.

Abstract: A downhole probe for use in conditions of high vibration or shock comprises a vibration-sensitive inner unit having a cylindrical outer surface, an outer casing having a cylindrical inner surface within which the inner unit is accommodated, and an intermediate vibration-damping composite sleeve extending between said inner and outer surfaces. The composite sleeve has two coaxial sleeve parts fitting one within the other and consisting of an apertured metal sleeve part and an elastomeric sleeve part having axial ribs which extend through axial slots in the apertured sleeve part. The axial ribs of the elastomeric sleeve part engage the inner surface of the outer casing and inner surfaces of the elastomeric sleeve part engage the outer surface of the inner unit so as to support the inner unit within the outer casing in such a manner as to provide efficient isolation of the inner unit from external vibration and shock.

Abstract: The present invention relates to an electron detector for use in a scanning electron microscope. The detector is used to detect high and low energy backscattered electrons as well as secondary electrons. The detector is based on the use of a high transparency conductive film over the surface of the detector, whereby the surface is stable to the application of a high voltage. The detector is be used to detect both high and low energy backscattered secondary electrons and has an active surface with an adjacent fine metal mesh grid which is used to transmit electrons without loss of energy, while at the same time providing a conductive surface over the surface of the detector material.

Abstract: A mobile radiation monitor includes a radiation detector unit and a signal analyzer connected to it. The radiation detector unit includes a base, a flat pad radiation scintillation detector on the base, and a bridging platform connected to the base and extending over the radiation scintillation detector to provide a walkway over it. Radiation from a subject on the bridging platform, producing an effect in the scintillator, is monitored at the signal analyzer. The radiation detector unit includes handles for mobility and anti-slip pads for safety.

Abstract: An apparatus for detecting the fluorescence of a luminescent material. Photo-diodes receiving the visible fluorescence from a target luminescent material and a luminescent reference are coupled "back-to-back" resulting in a single-channel detector inherently balanced and insensitive to variations in the excitation stimulus. The photo-diode output is sent through a second harmonic amplifier making available a phase detection of the fluorescence instead of an amplitude detection. The phase of the signal is compared with a known phase from the excitation power source. By adding signals that either reinforce or oppose, the phase information is converted back to amplitude information at a voltage level that can be easily detected. The detected amplitude is compared against the amplitude of the excitation stimulus to account for amplitude variations in such stimulus. The compared output then triggers an indicator producing an indication of the amount of fluorescence of the target luminescent material.

Abstract: A housing of a radiation detector is disclosed which comprises a radiation detecting cassette having a light-shielding cassette case with accommodating grooves delineated by partitions integral with the cassette case, a radiation detector accommodated in each of the grooves and which is composed of a scintillator and photomultiplier tube, and a cover that closes the cassette case. A flowable and light-shielding filler material is injected into the space between each of the grooves and the radiation detector and cured after closing the cassette case with the cover.

Abstract: A multi-channel type solid-state X-ray detector includes a base plate, multi-channel photodiodes arranged on the upper surface of the base plate and having one ends connected as output terminals to electrically conductive lines on the base plate, and a number of scintillators disposed on the photodiodes of respective channels, for generating scintillation light corresponding to incident X-rays when the X-rays are irradiated. Those end portions of the scintillators which lie on the other ends of the photodiodes are extended and a light emitting diode arranged in a flat plate configuration is disposed in contact with the underside of the extended portions on the upper surface of the base plate. The scintillators are shielded with respect to light on portions other than the underside which is in contact with the light emitting diode and photodiodes by reflective coating material or the like, and light from the light emitting diode is permitting to be projected into the entire portion of the scintillators.

Abstract: Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses.

Abstract: A device for measuring radioactivity for a machine for use in the extraction of radioactive ore and including at least one moving receptacle (18) suitable for containing a load of ore. The device comprises a rod (120) having its top end hinged to the machine in such a manner as to leave the rod free to swing in at least one vertical plane, the bottom end of the rod having a radioactive radiation detector (122) covering a determined solid angle, the device further including displacement means (140, 166) for bringing the rod and the receptacle in reproducible manner into a mutual disposition such that the load of ore contained in the receptacle occupies a substantial portion of the solid angle of the detector. An arm (110) is preferably provided between the rod and the machine.

Abstract: An improved radiation detector containing a crystalline mixture of LaF.sub.3 and CeF.sub.3 as the scintillator element is disclosed. Scintillators made with from 25% to 99.5% LaF.sub.3 and the remainder CeF.sub.3 have been found to provide a balance of good stopping power, high light yield and short decay constant that is equal to or superior to other known scintillator materials, and which may be processed from natural starting materials containing both rare earth elements. The radiation detectors disclosed are favorably suited for use in general purpose detection and in positron emission tomography.

Abstract: A radiation detector basically comprises a scintillator, a light guide for introducing scintillation light, and a photodetector for detecting the scintillation light. A light output portion of the scintillator is wedge-shaped, and a light input portion of the light guide is V-shaped in section so as to receive the wedge-shaped light output portion of the scintillator. With this arrangement, light reflection at the interfaces of the scintillator and light guide is reduced, resulting in an improvement of transmission efficiency of light.

Abstract: An alpha particle radiation probe which eliminates the need for any intermediate light coupling devices between the scintillation generating phosphor and scintillation detector while at the same time providing uniform response to alpha particles over a substantially larger area than has heretofore been possible on the order of 100 cm.sup.2 to 150 cm.sup.2. The structure is arranged to quickly replace a light blocking screen that has been damaged in use. Significant reductions in weight and cost are also achieved because of the simpler construction and the elimination of the light coupling devices heretofore used. The apparatus eliminates the need for a second small aperture probe detector for localizing radiation hot spots by providing aperture reducing means quickly attachable to and detachable from the scanning window to reduce its aperture and provide the hot spots detection function simply and inexpensively.

Abstract: A scintillation detector capable of withstanding high shock and/or high temperatures, comprises a scintillation crystal, a casing for the crystal, and a shock absorbing boot interposed between the crystal and the casing. The boot is characterized by a plurality of radially outwardly directed protrusions for engaging the casing. The protrusions define therebetween unfilled spaces to provide room into which the boot may expand at high temperatures. The protrusions may be longitudinally or radially extending ribs and the ribs may be generally rectangular or triangular in cross section. A reflector surrounds the crystal and preferably is in the form of a thin porous sheet of polytetrafluoroethylene (PTFE) wrapped tightly around the crystal. The boot preferably has a substantially continuous cylindrical interior surface for engaging the thin porous PTFE sheet to avoid high pressure concentrations.

Abstract: Apparatus for performing and measuring chemical reactions includes a reaction test apparatus having reaction wells wherein reactants are controllably mixed, and exposure apparatus which receives and positions the reaction test apparatus adjacent a photographic film. Each of the reaction wells includes at least two reaction chambers, arranged in a side by side fashion. All but the final reaction chamber have upwardly sloping sides, so that liquid placed in one reaction chamber can flow to the next reaction chamber when the apparatus is tilted. In a preferred embodiment, the reaction wells are supported in a plate that is structurally integral with the wells but separates the wells from each other. The test plate is retained in the exposure apparatus, and liquid is controllably flowed from one reaction chamber to the next by tilting the exposure apparatus.

Abstract: A carrier for at least on beta-particle-emitting sample to be measured in a scintillation counter comprises a sorption sheet on which the sample is to be deposited, a transparent bag within which the sorption sheet with the sample is to be contained, and a scintillant to be contacted with the sample within said bag. According to the invention the scintillant is a meltable solid scintillant which is coated onto at least part of the sorption sheet and/or the inside of the transparent bag, and which is to be melted to envelop and permeate the sample before measurement thereof.

Abstract: An arrangement for counting detectable events, such as scintillation events in a specimen sample utilizes first and second detector elements arranged on either side of the sample. The first detector is of the type which is able to produce information relative to the position of the event in the sample. The second detector generates a timing signal responsive to the detected event. In certain embodiments, the first detector also issues a timing signal in response to the detection of the event, and both timing signals are compared for temporal coincidence, whereupon circuitry for determining the position of the detectable event is triggered. The total energy of the event can be obtained from addition of the analog amplitudes of the timing signals. In certain embodiments, the second detector also produces position information, and the first and second detectors may provide respective coordinate values of a coordinate pair.

Abstract: A scintillator for use as a gamma ray or like radiation detector is composed of a single crystal of cerium-activated lutetium oxyorthosilicate having the general formulation Ce.sub.2x Lu.sub.2(1-x) SiO.sub.5. In a borehole logging application, the detector is mounted in a logging sonde with a high energy neutron source, for movement through a borehole traversing earth formations. Gamma radiation from the surrounding formations is detected and analyzed to provide information concerning hydrocarbons in the formations.

Abstract: A radiation scintillation detector which is particularly suited for X-ray detection is formed as a solid body of rotation about a central axis of a scintillator medium. The body includes at least one internal reflective surface, and at least one substantially planar surface through which the light is substantially transmitted to a photomultiplier tube. The curvilinear axial cross-section of the internal reflective surface is formed such that substantially any light originating from an area in proximity to a point of most probable emission within the body and intersecting the internal reflective surface is totally reflected internally. The photomultiplier tubes will receive most of the light emitted, by virtue of the decreasing taper of each internal reflective surface as it approaches the planar surface.

Abstract: A scintillation detector comprising a solid luminophor with a photomultiplier tube having its face abutting one surface of the luminophor to receive light generated in the luminophor by impinging radiation. The luminophor 11 includes polished outer surfaces 12 covered by light reflective opaque material 13 such as a thin aluminum foil or mylar coated with an aluminum reflecting film. The metal film blocks ambient and internal light while allowing radiation such as gamma rays or beta particles to penetrate, strike the luminophor and cause scintillation. Light emitted by the scintillation is directed through opening 14 to strike the face of photomultiplier tube 16.

Abstract: An optical ionizing radiation detector system (10) for determining the three-dimensional spatial distribution of all of the secondary electrons produced by the passage of ionizing radiation through a selected gas is provided. The detector system (10) can be used over a wide range of particle energies and gas pressures. The ionizing radiation passing through the gas produces prompt fluorescence and secondary electrons. A coincidence detector (30) recognizes coincident events of prompt fluorescence in the gas contained within that chamber to initialize the system cycle. At that time, an AC electric field is generated by an R.F. pulse generator (40) to localize the secondary electrons proximate their respective positions of production. Cameras (42) and 42'), preferably of a digital type, produce an image of the localized electrons to determine their three-dimensional spatial positions.

Abstract: A solution which increases the efficiency of radon extraction from either dry or moist charcoal samples is disclosed. The addition of low molecular weight organic solvents such as methanol or ethanol to liquid scintillation counting solution increases radon extraction from 20-500% over known counting solutions. The increased efficiency appears to occur from increased penetration of the charcoal by the low molecular weight solvent which dissolves the radon gas and the subsequent diffusion of the low molecular weight solvent out of the charcoal and into the liquid scintillation counting solution.

Abstract: An alpha-ray image detecting apparatus detects the image of alpha-rays emitted from nuclides of a substance by analyzing the electrons emitted from the substance. The apparatus includes a vacuum chamber having a layer of fluorescent material at one end and an electronic optical system for multiplying the emitted electrons and focusing the emitted electrons on the fluourescent layer.

Abstract: A well logging detector includes an elongated scintillation crystal having one end biased against and optically coupled to a transparent window portion of the detector housing. The biasing force on the crystal is provided by a compression spring located at and bearing against the other end of the crystal. The biasing force applied to the crystal by the spring is weak enough to allow the crystal to move away from and optically decouple from the window portion in response to shock forces on the detector. Subsequent to such shock induced decoupling, the biasing spring moves the crystal against the window portion to re-establish optical coupling therebetween. Such a biasing structure precludes excessive axial loading of the crystal by shock forces tending to move the crystal against the window as opposed to away from it. Such a shock resistant detector is especially well suited to measurement-while-drilling (MWD) applications.

Abstract: A plastic scintillator element that is tissue equivalent is optically coupled to a photomultiplier tube that provides a pulse signal which contains information relating to radiation energy fluence, and having an undesirable "dark current" component. A direct current blocking element in the form of a capacitor isolates the input of an operational amplifier from the "dark current" component so that the output signal of the amplifier indicates the average current of the photomultiplier signal attributed only to detected, low level, environmental radiation in the range of 0-200 .mu.rem/h.

Abstract: A plurality of semiconductor radiation detector elements are arranged in a matrix array. The same number of signal process circuits as the detector elements are exclusively connected to the respective detector elements. The detector signals derived from the individual detector elements are independently stored in predetermined memory cells of a frame memory. Further, a coding circuit is connected between the signal process circuits and the frame memory.

Abstract: A system which couples Cerenkov emission with a gated electrooptic effect to allow viewing of Cerenkov radiation in sub nanosecond time-scales is disclosed. Cerenkov radiation is generated by transmitting an electron beam through a transparent medium with a high index of refraction. The Cerenkov radiation is then gated into a sample pulse of subanosecond duration by an electrooptic crystal which has an index of refraction controlled by an electric field. the electrooptic crystal is opaque to the Cerenkov radiation until receiving a 6.0 kV voltage for about 750 picoseconds, upon which a pulsed sample of Cerenkov radiation is transmitted to a display system.

Abstract: A high-temperature well logging instrument of the scintillation detector type includes a plastic scintillation element susceptible to softening and deformation at high operating temperatures. To maintain the shape of the scintillation element at such high temperatures, a metal retaining cup holds the scintillation element in its original shape. The retaining cup with the scintillation element inside is capped at its open end by a silicon rubber pad that is transparent to photons generated by the scintillation element in response to detected radiation. A biasing spring holds the end face of a photomultiplier tube against the silicon rubber pad so as to sandwich the pad between the photomultiplier tube and the open end of the metal retaining cup. Such a configuration maintains excellent optical coupling between the scintillation element and photomultiplier tube during high-temperature well logging.

Abstract: In a neutron and/or gamma radiation detection system, a large reception surface for the radiation to be detected is formed on a body of scintillation material which is adapted to convert neutron or gamma radiation into light energy. A large number of fiber light conductors is embedded in the body of scintillation material such that the fibers extend essentially parallel and fully across the reception surface of the body of scintillation material. The light energy, upon propagation along the fiber light conductors, is coupled into the conductors along the surface of the fibers, which fibers are anisotropic.

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 and apparatus are disclosed for measuring a velocity component of a moving fluid. Coherent light at two different wavelengths is directed into the moving fluid to create a space-and-time modulated optical field within a sample volume and to cause a chemical component of the moving fluid to fluoresce. Measurement of temporal and/or spatial characteristics of the resulting fluorescence is employed to determine the velocity component of the moving field.

Abstract: A method and apparatus for calibrating the detector gain of a dual energy digital radiography system is provided. A basis material calibration object is scanned to create low and high energy pixel data. A regression is performed on the pixel data to derive at least one high energy calibration vector and at least one low energy calibration vector. The calibration vectors are transformed into high and low energy gain functions represented by a Taylor series expansion. An examination object is scanned to create low and high energy image data. The image data is combined with the gain function to create corrected low and high energy image data.

Abstract: A scintillation camera apparatus comprises a plurality of photomultipliers, a plurality of high voltage control circuits, and a comparator. The photomultipliers generate radiation energy signals upon receipt of incidence light. The comparator compares the peak pulse heights of the radiation energy signals with the corresponding reference peak values to derive deviation signals. Based upon the deviation signals, the supply of the high voltages to the photomultipliers is independently controlled.

Abstract: A scintillation detector is provided which has a scintillation member comprised of a substance which converts energy received in the form of an ionizing particle to light. The scintillation member, such as a thallium-activated alkali halide crystal, is sealed in a housing containing an atmosphere which is substantially non-reactive to the scintillation member at temperatures ranging from about 100.degree. C. to about 250.degree. C. Examples of suitable atmospheres include the noble gases including helium, neon argon, krypton, xenon and radon; nitrogen; carbon dioxide, a vacuum, and other atmospheres, such as mixtures of these or air which has been substantially depleted of oxygen. Processes for the manufacture of the detector are taught where the scintillation member is encapsulated in a non-reactive atmosphere such as ones listed above. Alternatively, the reactive atmosphere can be washed from the housing or the sealed housing can be evacuated and refilled with a non-reactive atmosphere.

Abstract: The presence of certain chemicals on the emitting surface of the surface-derivatized photoluminescent semiconductor alters the characteristics of radiation emitted from said surface. This alteration is used to indicate the presence of those chemicals in the environment.