Abstract: A radiation detector circuit, which comprises a radiation detector containing a scintillation crystal and a photomultiplier tube for real time photon measurement having a pulse output, and which also includes a plurality of pulse counters each having a pulse input and a count signal output. Between the pulse output of the photomultiplier tube and the pulse inputs of the pulse counters a time multiplexer is provided for connecting each pulse input of each counter in succeeding time periods with the pulse output of the photomultiplier tube. Furthermore, an evaluation circuit is connected with the count signal outputs of the counters for evaluating each count signal of each counter measured during each of said succeeding time periods in the sense of error estimates and trend analysis.

Abstract: Body structures into which a gamma-emitting isotope has been introduced are investigated using an imaging system comprising in sequence a collimator, a first detector, a filter, and a second detector. The first detector is partially transparent to the emerging photons and the filter is adapted to have an absorption edge energy fractionally less than the energy of the radioactive isotope source. The first detector produces an image of both scattered and non-scattered photons and the second detector simultaneously produces an image of only the scattered photons. The two images can be manipulated to produce an image due only to non-scattered photons which is the image of interest.

Abstract: Apparatus and method for detecting light involve applying a substantially uniform electrical potential difference between first and second spaced surfaces of a body of mercuric iodide, exposing the first surface to light and measuring an electrical current passed through the body in response to the light. The mercuric iodide may be substantially monocrystalline and the potential may be applied between a substantially transparent conductive layer at the first surface and a second conductive layer at the second surface. In a preferred embodiment, the detector is coupled to a scintillator for passage of light to the mercuric iodide in response to ionizing radiation incident on the scintillator.

Abstract: Method and apparatus for evaluating subsurface formations utilizing natural gamma radiation spectral measurements. The total counts measurement is processed to derive measurements relating to the concentrations of potassium-40, uranium and thorium. A relative concentration factor of uranium to the energy spectra is derived and the total counts measurement is compensated by the uranium factor to remove the effects of uranium.

Abstract: A method and device for stabilizing photomultiplier tubes of a radiation image device against drift by illuminating the photomultiplier tubes with light. A certain number of the photomultiplier tubes are arranged in an array for final application. Then the complete array is illuminated for a certain time period with light having an intensity to produce an average anode current in the photomultiplier tubes which is in the range of 1 to 50 .mu.A.

Abstract: This invention describes apparatus for and a method of measuring radiation field strength which uses a pulse enabled detector (e.g. G-M tube) and is based on the equation R=K/t, where R is the radiation field strength, t is the time till first strike, and K is a proportionality constant for the given apparatus. The G-M detector is enabled by pulsing the bias voltage across the detector up into its active region and then measuring the elapsed time interval to the incident of first strike. Since the reciprocal of this time is proportional to the radiation field strength, all information necessary to determine the field strength has been obtained. A constant wait time is employed after each strike to assure that the G-M tube full recovery time has expired, and the G-M tube is then enabled and the process repeated. Because of the random nature of radiation phenomena the confidence level that any given measurement is an accurate representation of the true average field strength is low.

Abstract: A radiation measuring device comprises a scintillator for detection of radiation, a photomultiplier tube and an amplifier circuit for supplying signals having amplitudes dependent on the output current of the photodetector. A first series circuit of a sampling and digital-to-analog converter circuit and an adder is provided with a first storage register connected to the adder. A second storage register is connected to the output of the adder, and the output of the second storage register provides the output of the measuring device. A second series circuit is connected to the output of the photodetector or the amplifier circuit, and includes a pulse start detector, a clock pulse generator, a clock pulse counter, and a comparison circuit. The output of the comparison circuit is connected to the second storage register for storing a sum signal which is supplied by the adder, as well as the first storage register, in order to reset the first storage register to zero.

Abstract: A radiation image-converting panel has a stimulable phosphor layer formed on its base. On this stimulable phosphor layer there is formed a transparent protective layer, on which an auxiliary protective layer is pasted by a adhesive so that it can be peeled from the protective layer. In an apparatus for reading out a radiation image from the radiation image-converting panel, an adsorptive cup adsorbed to the base is moved in a subscanning direction and, at the same time, an adsorptive cup adsorbed to the auxiliary protective layer is rotated. Thus, the auxiliary protective layer can be peeled off from the protective layer. While the auxiliary protective layer is peeled, laser beams are caused to scan the stimulable phosphor layer through the protective layer. The phosphorescence emitted by this scanning is detected by a photodetector through a condensing portion.

Abstract: Methods for measuring thermal neutron decay characteristics of earth formations include the steps of irradiating an earth formation with a discrete burst of fast neutrons, detecting indications of thermal neutron concentration in the formation during a sequence of discrete time gates, determining the zeroth order moment of the indications during the sequence of discrete time gates, and determining the first order moment of the indications during the sequence of discrete time gates, in order to obtain the desired thermal neutron decay characteristic of the earth formation.

Abstract: A mammography compression system provides for both non-magnification compression examination as well as magnification compression examination through a large plurality of positions whereby the patient may remain seated upright or standing. The system permits utilization of a radiologist's present in place X-ray equipment and readily mounts for juxtaposition with the existing in place x-ray system.

Abstract: A radiographic apparatus for photographing the entire jaws designed to make a tomogram of a curved plane approximate to a dental arch by the locus of center of rotation of the X-ray beam projected from an X-ray source onto an X-ray film holder describing an approximately V-shaped envelope which forms an apex on an approximate medial line and recedes from the apex toward the left and right of the approximate medial line by moving a rotary arm around a patient, the arm having the X-ray source at one end and the X-ray film holder at the other end thereof, wherein the apparatus comprises a means for changing straight-line distance on the approximate medial line between the apex and receding point of limit of the envelope and a means for indicating the distance of shift thus changed or a means for automatically moving the indication means a distance equal to the distance of shift.

Abstract: A method and apparatus for producing X-rays utilizing the Compton backward scattering effect. The X-rays are electronically steerable for scanning, and also have a very narrow angle of divergence for precise positioning. The X-rays have a narrow bandwidth, and are tunable to permit an object to be irradiated with only the desired beneficial radiation. The X-rays are polarized for trace element analysis. The X-rays are suitable for medical diagnostic and therapeutic, and industrial testing, purposes.

Abstract: A multielement radiation detector in which many elements are arranged in array. Each element includes a scintillator which is tilted with respect to the incident direction of radiant rays, and a silicon photodiode which is opposed to the plane of incidence of the scintillator. The light-receiving plane of the silicon photodiode is tilted to meet the inclination of the scintillator. Therefore, the gradient of detection sensitivity distribution is reduced in the thickness direction of the detectors.

Abstract: A dosimeter for measuring the intensity of high energy electron, photon, or other particle radiation has ion, electron, and radiation shields about at least respectively sensitive components of the dosimeter. The entire dosimeter, therefore, can be assembled as a unit and portably placed in the radiation to be measured. Ruggedness for this desirable partability is provided by the use in the dosimeter of a pancake ionization chamber which also eliminates the need to calibrate radiologically the dosimeter.

Abstract: A gamma ray density sub and method useful for measurement-while-drilling applications utilizing three pairs of gamma ray sources and detectors located symmetrically about the axis of the sub and computation of the product of the counting rates obtained from the three detectors to indicate the average density of a formation sample surrounding a borehole traversing an earth formation. The sub is able to measure the density of the sample, independent of the location of the sub within the borehole and the chemical composition of the interfering materials lying between the formation sample and the detectors.

Abstract: In the disclosed device a film loader loads film sheets of different length to be exposed by X-rays. A transport arrangement transports the sheets to positions at which they are to be exposed. A holder keeps the upper edge of the film sheets at the same height in the exposure position regardless of the sheet length.

Abstract: A hand-powered alternator for generating an alternating voltage provides same through a rectifier to a high capacity capacitor which stores the resultant dc voltage and drives a voltage regulator to provide a constant low voltage output for a portable radiation detection instrument. The instrument includes a Geiger-Muller detector tube whose output is fed to a pulse detector and then through an event counter and LCD driver circuit to an LCD bar graph for visual display. An audio driver and an audio output is also provided. All circuitry used is low power so that the capacitor can be readily charged to a sufficient level to provide power for at least 30 minutes. A low voltage indicator is provided on the LCD display to indicate the need for manual recharging.

Abstract: The apparatus measures the thickness of thin layers according to the X-ray fluorescence principle. It has an X-ray beam generator which emits an X-ray beam along a longitudinal geometrical axis, a table device arranged to support a layer which is to be measured, a diaphragm device of a material which absorbs X-rays completely, having a through-aperture which is moveable into the longitudinal geometrical axis, a light source for visible light which can be directed onto the region for the layer, a monocular microscope arrangement for viewing the region of the layer on which the X-ray beam falls, and a deflecting mirror in the optical path between the monocular microscope arrangement and the region of the layer. The diaphragm device is composed of a glass which is transparent to visible light, and has several through-bores therein of different cross-sectional geometry.

Abstract: Device for ionizing a material, comprising a tube open at its two ends, and wherein first end of the tube is heated to a temperature permitting the ionization of the material, the second end of the tube being kept at a relatively low temperature, so as to produce a temperature gradient between the ends of the tube and wherein the material is introduced into the tube by the second end thereof, whereat the ionization of the material is also checked.

Abstract: An imaging proportional counter which significantly reduces parallax errors when imaging point sources of radiation located at variable distances from the detector entrance window. The imaging proportional counter includes a gas filled enclosure with a concave shallowly curved radiation permeable entrance window allowing radiation from the source to enter the enclosure. A multi-wire grid assembly is spaced behind the entrance window within the enclosure. When a potential difference is applied between the grid assembly and concave entrance window an electrostatic field is generated such that near the interior surface of the window the field lines form a spherically focussed region. The concave entrance window also allows increased fill gas pressures such that radiation entering the detector will interact with the fill gas very near the entrance window while still in the spherically focussed region.