Abstract: The apparatus and method provide techniques for effectively implementing alpha and/or beta and/or gamma monitoring of items or locations as desired. Indirect alpha monitoring by detecting ions generated by alpha emissions, in conjunction with beta and/or gamma monitoring is provided. The invention additionally provides for screening of items prior to alpha monitoring using beta and/or gamma monitoring, so as to ensure that the alpha monitoring apparatus is not contaminated by proceeding direct to alpha monitoring of a heavily contaminated item or location. The invention provides additional versatility in the emission forms which can be monitored, whilst maintaining accuracy and avoiding inadvertent contamination.

Abstract: A dose distribution measuring method capable of grasping a three-dimensional form of an object to be measured or evaluating a three-dimensional dose distribution thereof. The method comprises providing a multiple-eye type radiation meter probe in which at least two directional radiation detectors are arranged so as to be spaced from each other and directed toward a point to be measured; and carrying out dose measurement by directing the radiation meter probe toward an object to be measured from different positions to thereby determine a three-dimensional dose distribution of the object to be measured. Each of the radiation detectors has a structure in which a periphery of the radiation detector main body, except for a detection surface thereof, is surrounded by a radiation shield to reduce the effect of radiation from other than the object to be measured and from Compton scattering.

Abstract: A directivity-type radiation detecting apparatus capable of detecting a particular radiation source or a moving situation thereof even in the high radiation atmosphere. A multiplicity of radiation detector probes are dispersedly arranged in different directions on an outer surface of a radiation shield. Alternatively, a multiplicity of penetration holes are dispersedly formed in different directions in a shell-shaped radiation shield and radiation detector probes are respectively disposed in the penetration holes of the radiation shield. The above-described directivity-type radiation detecting apparatus is used to compute and process a position and a direction of each radiation detector probe and a value measured by each radiation detector probe, whereby a position, a distribution situation or a moving situation of a radiation source is detected.

Abstract: The apparatus and method provide a technique for more simply measuring alpha and/or beta emissions arising from items or locations. The technique uses indirect monitoring of the emissions by detecting ions generated by the emissions, the ions being attracted electrostatically to electrodes for discharge of collection. The apparatus and method employ a chamber which is sealed around the item or location during monitoring with no air being drawn into or expelled from the chamber during the monitoring process. A simplified structure and operations arises as a result, but without impairing the efficiency and accuracy of the detection technique.

Abstract: A Compton camera has two detectors which each sense the location, energy and time of photon collisions. Compton events are detected in which a photon emanating from the subject collides with one detector at energy (E1) and then the second detector at (E2), both energies E1 and E2 are measured and used in conjunction with an initial photon energy E0 to increase the resolution of the camera.

Abstract: A multi-detector system receives incident radiation through a subject includes a gaseous microstrip detector, which has alternating anodes and cathodes on a substrate opposite a voltage source, is positioned adjacent a semiconductor detector. In a dual energy environment, electric fields are applied to both detectors as the incident radiation is directed therethrough. A gas electron multiplier is placed within the gas microstrip detector, and a potential is applied thereto to improve the generated signal. To further improve this signal, the anode and cathode may be operated as a Frisch Grid. Accordingly, the detectors generate corresponding signals which are compared to generate a contrasted signal of the subject. These signals may be generated for imaging, radiation monitoring, radiation measuring and the like. The direction of incident radiation and the orientation of the electric fields may be adjusted according to the particular application.

Abstract: A vest useful for work in radioactive environments is provided. The vest comprises (a) a garment for substantially traversing the upper body of a user while being supported by the shoulders of the user, the garment having a front portion, a rear portion, opposed side portions and opposed shoulder portions, (b) a pocket disposed on the portion of the garment for accepting and retaining a communications data transmitter with dosimeter, and (c) a pair of adjustable sleeve elements attached to the garment, each sleeve element having a sleeve pocket for accepting and retaining a remotely transmitting dosimeter probe at a position above the elbow of the user. The invention has been found to provide a convenient method for firmly retaining at least five personal teledosimeter detectors on the upper torso of a worker having to work within a radiation hazardous environment.

Abstract: In one aspect, the invention encompasses a method of detecting radioactive decay, comprising: a) providing a sample comprising a radioactive material, the radioactive material generating decay particles; b)providing a plurality of detectors proximate the sample, the detectors comprising a first set and a second set, the first set of the detectors comprising liquid state detectors utilizing liquid scintillation material coupled with photo tubes to generate a first electrical signal in response to decay particles stimulating the liquid scintillation material, the second set of the detectors comprising solid state detectors utilizing a crystalline solid to generate a second electrical signal in response to decay particles stimulating the crystalline solid; c) stimulating at least one of the detectors to generate at least one of the first and second electrical signals, the at least one of the first and second electrical signals being indicative of radioactive decay in the sample.

Abstract: A person intervening on the site is fitted with a plurality of radioactivity meters (1, 2, 3, 4, 11, 12) distributed over the body at locations such that at least two meters receive radiation doses that are different due essentially to the screen constituted by the body of the intervener, and the radiation doses received simultaneously by the meters are compared to deduce therefrom information concerning the direction towards the source relative to the intervener.

Abstract: The invention pertains to a measurement device comprising two sensors for measuring radiation doses. The sensors are, for example, optical waveguides aligned along a straight line. One of the optical waveguides covers a longer section along the line than the other waveguide; in particular, the difference is at least 20 mm. Measurement using the measurement device is done as follows: the radiation dose along the line of radiation down to the expected penetration depth is measured using the wider sensor; the narrower sensor is used to determine the radiation dose in a volume element within the radiation path. A quotient is formed from the two measurements and used to calculate the radiation depth on the basis of reference values. The proposed device facilitates rapid and simple determination of a penetration depth of an ionizing radiation, for example in tissue.

Abstract: A multi-detector system receives incident radiation through a subject includes a gaseous microstrip detector, which has alternating anodes and cathodes on a substrate opposite a voltage source, is positioned adjacent a semiconductor detector. In a dual energy environment, electric fields are applied to both detectors as the incident radiation is directed therethrough. Accordingly, the detectors generate corresponding signals which are compared to generate a contrasted signal of the subject. These signals may be generated for imaging, radiation monitoring, radiation measuring and the like. The direction of incident radiation and the orientation of the electric fields may be adjusted according to the particular application. Additionally, the system can be utilized in a single-energy environment where two images of the same incident radiation energy will be formed from the different detector media. By utilizing various processing techniques enhanced contrast between the images can be obtained.

Abstract: A photoconductive, high energy photon beam detector/monitor for detecting x-rays and gamma radiation, having a thin, disk-shaped diamond substrate with a first and second surface, and electrically conductive coatings, or electrodes, of a predetermined configuration or pattern, disposed on the surfaces of the substrate. A voltage source and a current amplifier is connected to the electrodes to provide a voltage bias to the electrodes and to amplify signals from the detector.

Abstract: A wide range radiation detector which can precisely detect high energy region radiations. The detector has a plurality of layered semiconductor elements wired in parallel, and outputs the energy of the radiation by summing the charges generated by ionization of the radiation incident on the semiconductor elements.

Abstract: An ultralow background multiphoton detectors device for radioisotopes has a background of about one count per day. Two opposed gamma and X-ray photon detectors each preferably include a scintillation crystal and a photomultiplier tube. Sandwiched between the detectors are a separator and a sample holder for a sample labelled with a radioisotope such as I.sup.125. The detectors convert emissions from the radioisotope into electric output pulses which are then subjected to signal processing for pulse shape analysis, discrimination of coincident from non-coincident events, and quantification of the radioisotope. Detector materials and components are selected to minimize background, and are shielded from external radiation. The device may further be constructed to resolve and provide images of two dimensional sample arrays.

Abstract: A patient detection system having a plurality of optical sensors associated with a corresponding plurality of file receptacles at a health care facility. The optical sensors are interfaced with one or more visual display devices. Insertion of a patient's file into a file receptacle automatically generates an output signal that activates remotely located corresponding visual indicators that notifies health care personnel that a patient is waiting.

Abstract: A counting enclosure (24) for neutron detection has an outer wall and an inner space for receiving an object (26) to be tested, the wall being constituted by a first, inner cadmium coating (32), an inner moderator coating (38), an intermediate cadmium coating (34), an outer moderator coating (40) and an outer cadmium coating (36).

Abstract: A bolometric detection device for millimeter or sub-millimeter waves and a method for manufacturing this device. According to the invention, at least one bolometer (8) is formed on a support (6) which is transparent to the waves to be detected, each bolometer including a reflecting resonant cavity (10), a grid (12) thermally insulated from the support and positioned above the cavity, regular conductor patterns (14) which are formed on the grid and whose electrical impedance is matched to that of the void, and a thermometer (16) integral with the grid.

Abstract: An integrated charge monitor for measuring a level of cumulative radiation exposure includes semiconductor devices having characteristics that change with a cumulative level of radiation to which the devices are exposed, different amounts of radiation shielding associated with each of the devices, and circuitry operable to separately address each of the devices to measure a change in the characteristic of the selected device due to radiation exposure. The monitor may be implemented on a single integrated circuit chip. The monitor may also be employed in performing a spectrometric analysis of radiation based on the affect of the radiation on characteristics of multiple, differently-shielded semiconductor devices.

Abstract: A device is provided for permitting real time measurement of the activity of dust confined in a ventilation duct. The device includes a radiation emitter for producing a beam for traversing the duct and a light radiation detector placed in front of the beam. The device also includes at least one gamma radiation detector placed facing the ventilation duct. An acquisition unit and a control unit are also provided for acquisition and processing of real time dust activity measurements. Particular utility is found measuring activity of dust leaving a furnace used for melting nuclear installation scrap.

Abstract: A radiation detection system and method for scanning an object for ionizing radiation are generally characterized by at least one radiation detector which provides an output related to the level of ionizing radiation impinging thereon, a sensing device which evaluates and provides an output related to a shape characteristic of an object being scanned by the radiation detector, and a processor operatively connected to the radiation detector and sensing device for processing the outputs thereof. The output of the sensing device is used to compensate for variations in ambient background level arising from the sensed shape characteristic of the object. With such a system, the possibility of a geometry induced false alarm is minimized. In a preferred embodiment adapted for dynamic vehicle monitoring, the sensing device is a level detector operative to detect the level of the material in a truck or rail car passing by the radiation detector or detectors.

Abstract: A method for measuring the fixed contamination level in a confined area such as small diameter pipe. The method measures the accumulated detection response over a given area and prescribed time period. To obtain the measurement a plurality of sensors are connected in tandem to form a flexible detector string and remotely positioned within the area to be monitored. The measurement is correlated to a standard obtained by using a known source in a simulated mockup environment. In one embodiment a passive monitor such as a Thermo-Luminescence Dosimeter is employed as the sensor.

Abstract: A radiation monitoring system and method characterized by the use of paired active and passive radiation detectors to monitor exposure to a radiation field. The active detector provides an output representative of radiation exposure on a real time basis while the passive detector is readable on a delayed basis after exposure to radiation for a period of time to provide an output representative of radiation exposure over said period of time. Respective readers are provided for extracting the radiation exposure information from the detectors, as is a processor which determines a quantity of radiation exposure from the radiation information extracted from the detectors. The processor corrects radiation exposure data derived from one of the detectors using radiation exposure data derived from the other of the detectors.

Abstract: An x-ray apparatus has a portable radiation detector having a housing containing a radiation transducer formed of individual detector cells that convert incident radiation, particularly x-radiation, into electrical signals. The radiation detector is implemented cable-free. A wireless transceiver for the infeed of operating energy and for the outfeed of the signals is provided. An advantage of this radiation detector is the cable-free construction, and the simple manipulation and reusability resulting therefrom. Moreover, the radiation detector is better suited to hygienic demands.

Abstract: Intended for use in a pathology laboratory, the apparatus includes a multi-segment crystal array over which is positioned a platform supported receiving region with a pattern carrying indicia emulating and in registry with the pattern of the crystal array segments. The tissue carrying a radiolabeled locator is positioned on the receiving region and the photon emission count values for each segment are compiled and displayed at a computer monitor or as a print-out in conjunction with crystal segment identification. Observation of the count values by a pathologist then shows the location over a segment of highest count value at which locator is more likely to be concentrated. Sectioning then is carried out at that location.

Abstract: Radiation monitoring systems for crates and containers, and small volumes of foodstuff and tobacco, and whole body animal monitoring system for measuring the radiation contamination levels of containers, foodstuff, tobacco or animals and in the case of animals particularly, livestock utilized for meat consumption. The containers or animals are weighed, identified and then directed through a specially constructed shielded holding area, wherein multiple radiation detectors measure the radiation level for the containers or animal in the pen. A microprocessor analyzes the data information and provides a respective output for each container or animal which in turn is compared with predetermined standards and input information. The particular reading per container or each animal monitored actuates controls to segregate the containers or animals by those having acceptable and non-acceptable levels of radiation. The non-acceptable segregated containers or animals are specially held for evacuation and for disposal.

Abstract: A method for determining the depth of a gamma emitting element beneath the surface of a volume of soil is disclosed. The disclosed method includes the steps of detecting gamma rays at a first height h.sub.1 above the surface; detecting gamma rays at a second height h.sub.2 above the surface; determining a ratio R representative of the ratio of the number of gamma rays detected at h.sub.2 to the number of gamma rays detected at h.sub.1, or vice versa; and inferring, on the basis of the ratio R, an estimate of the depth of the gamma emitting element beneath the surface.

Abstract: A device for detecting radiation within a pipe having one or more carriages adapted for movement through the pipe. A set of radiation sensors is mounted on each carriage for detecting radiation on the interior of the pipe. The radiation sensors are positioned to cover a complete circumferential strip on the pipe interior while maintaining the geometry required to meet U.S. government criteria for the unconditional release of the pipe. Readings from the radiation sensors are transmitted out of the pipe and recorded to establish a detailed radiological survey of the pipe interior.

Abstract: A position sensitive detector has one or more wedge-and-wedge anode units, each of which has four electrodes on a planar surface arranged in a plurality of sets of four wedge-shaped electrode elements each, with the sets extending across the anode unit. Two of the electrode elements become progressively wider from set to set from one side of the anode unit to the other, while the other two electrode elements become progressively narrower. The respective electrode elements in each set are electrically connected together to complete the four electrodes. The charge measured on each of the four electrodes can be utilized to determine the X and Y coordinates of an event which results in a charge cloud impacting the anode, with redundant information available from the four electrodes.

Abstract: The invention relates to a method for determining the distance of a target in difficult industrial conditions, method in which (i) one of the gamma quanta produced from a radioactive source in annihilation and traveling in opposite directions is aimed at the target and the other one at a detector, which detects it, and time measuring starts; (ii) the quantum Compton-scattered from the target is detected by the same or a separate detector, and time measuring stops; (iii) the distance of the target is calculated from the time difference between (i) and (ii). The invention also relates to a device for carrying out the method, the device comprising a radioactive source, a scintillation crystal counter/counters, a time-amplitude converter (TAC) and a pulse height analyzer (PHA).

Abstract: A process for determining the density distribution of positrons in human tissue in which the amount of position data stored in the computer memory from two parallel photomultiplier local position .gamma.-detectors is limited by a random-event generator connected to the computer.

Abstract: A method for detecting the angle of arrival at a receiver of ionizing radiation from a source of unknown specific activity at an unknown distance by using an active filter between the detector and source that varies the intensity of the radiation by a predetermine factor according to position and then comparing that value to an unshielded detector's value forming a geometric ratio to determine the angle of arrival of the radiation at the receiver in relation to a predetermined reference plane or line.

Abstract: A shielded dose calibration apparatus including one or more hand-held portable shield units containing a vessel with a radioactive sample in a shielded chamber and a calibration station for calibrating the sample in the vessel without removing the vessel from the protections of the shielded chamber. The shield units include on-board detectors for measuring the radioactivity from the sample. The calibration station may include a separate controller unit and one or more base units. To calibrate a sample, the portable shield unit is placed on a base unit, which senses the presence of the shield unit. The shield unit then communicates an identification signal and the data measured by the on-board detectors to the controller unit via the base unit. Power may also be transmitted to the shield unit via the base unit, avoiding the need for an on-board power source.

Abstract: The invention makes it possible to measure the degree of radioactive radiation emitted by large pieces. It includes two large gamma ray detectors (12A, 12B) placed opposite each other and whose spacing is adjustable. They are completed by a photoelectron multiplier (14A, 14B). The piece (2) to be measured is suspended so as to be brought between the two detectors (12A, 12B). The positioning of these detectors is obtained with the aid of a computer and a system (22) for recognizing the shape of the piece (2) functioning with the aid of optical clip-on lenses. The fact that the two detectors are position-adjustable makes it possible to take account of the shape of the piece to be measured. An application is the recovery of materials originating from nuclear installations with the view to re-using the materials.

Abstract: Device for the measuring of the activity and the volume of radioactive liquids with a shielding housing with a first chamber containing a vessel provided with a central hollow space and a ring chamber receiving the electrically conductive liquid to be investigated and with a second chamber separated from the first chamber by a wall with a vertical row of windows placed one above the other and in which a vertical row of sensors assigned to the row of windows is provided, each of said sensors being connected to an amplifier and to a counting device, whereby two separate rod-shaped electrodes dip into the vessel contained in the first chamber, one of these electrodes dipping into the ring chamber and being subjected to high-frequency impulses, while the other electrode extends inside the central hollow space of the container and is connected via an amplifier to a measuring device.

Abstract: A gantry for a multi-head scintillation camera including a pair of vertically disposed annular plates between which are mounted the scintillation camera heads. The plates are supported on their peripheral edges by rollers which both provide load bearing support and allow plate rotation. A pulley is mounted on one of the plates and is belt-driven by a motor.

Abstract: An orientation detector for radioactive sources is provided.Such detector comprises a homogeneous sphere containing six sensors arranged on three different diameters at a limited depth from the sphere surface. Comparison of the radiation received and differently attenuated by the material of the sphere makes it possible to deduce the angular disposition of the source relative to the detector.

Abstract: A portable personnel monitor that is easily transported, set up and operated to perform radiological contamination testing of personnel is provided by a collapsible frame containing scintillation detectors. The frame has hinged columns as side members and a top member which is releasably connected with electrical and mechanical connecting and alignment devices to the columns. A signal analyzer unit is attached to one column via a T-slot and is connected to the scintillator detectors via a coaxial cable. A base plate having upstanding posts supports the frame rigidly in an upright position and is releasably connected to the columns by push/pull pins. The frame defines a passage which is of sufficinet height so that an adult human subject can pass through the radiation sensitivity field defined by the detectors.

Abstract: This disclosure is directed to a detector system for use in measuring while drilling (MWD) equipment. It comprises preferably duplicate chambers positioned to one another and mounted in a MWD system where they are subject to the same shock and vibration. The shock and vibration impinge on the two chambers, and cause two output signals to be formed. The two output signals are applied to a differential amplifier so that the microphonic portion of the signal is cancelled. This then leads to a differential output signal which carries in it the signals representing nuclear events detected by the similar or duplicate detector means. Alternately, a single chamber can be used if it is provided with two anode wires and they are connected to the differential amplifier for signal cancellation.

Abstract: An improved apparatus for detecting radioactive contamination in garments. The apparatus includes a pair of radiation detectors spaced along a conveyor path. The conveyor system conveys the garments in a compressed condition and the garments are biased toward each of the detectors as they are conveyed therepast. A housing is provided with an air filtering system such that the conveyors are enclosed in a ventilated structure and the spread of contaminants accumulating within the housing is prevented. Preferably the conveyors include a thin, open grid arrangement which is strong, non-stick and includes an electrically conductive material which dissipates static charges. The detectors are gas-flow proportional and may be operated at a voltage optimized for sensing alpha particles. The detectors may also include plural zones some of which are operated at a voltage optimized for sensing alpha particles while others are operated at a voltage optimized for sensing beta particles.

Abstract: An electronic measurement circuit for high speed comparison of the relative amplitudes of a predetermined number of electrical input signals independent of variations in the magnitude of the sum of the signals. The circuit includes a high speed electronic switch that is operably connected to receive on its respective input terminals one of said electrical input signals and to have its common terminal serve as an input for a variable-gain amplifier-detector circuit that is operably connected to feed its output to a common terminal of a second high speed electronic switch.

Abstract: The Laser Line Identifier (LLI) is a real-time device which can indicate wavelengths of the laser radiations. LLI mainly consists of a beam splitter, narrow bandwidth transmission filters and detectors. The filters and the detectors form a unique pair so that a signal detected at a particular detector can only mean the radiation of a certain wavelength. The detectors are hardwired to a set of indicators such as a set of colored lights or a voice recording so that the wavelength of the radiation is clearly indicated even to a non-technical person.

Abstract: A high resolution directional gamma ray detector includes a thin piece of foil, such as tantalum, which reacts with gamma rays incident to the edge of the foil to generate electron/positron pairs. Gamma rays originating from directions other than a direction of interest are shielded from the foil by shielding plates. An opening between the foil by shielding plates. An opening between two collimating plates permits passage of gamma rays originating from a direction of interest and allows gamma rays originating from a direction of interest to react with the foil. The generated electron and positron cause ionization in a plurality of cells. Signals resulting from these ionizations are processed by an electronic computation system through the use of coincidence processing to determine whether the signals are the result of a reaction between the foil and a gamma ray which passed through the collimator opening.

Abstract: Multi-element high energy particle detector modules comprise a planar heavy metal carrier of tungsten alloy with planar detector units uniformly distributed over one planar surface. The detector units are secured to the heavy metal carrier by electrically conductive adhesive so that the carrier serves as a common ground. The other surface of each planar detector unit is electrically connected to a feedthrough electrical terminal extending through the carrier for front or rear readout. The feedthrough electrical terminals comprise sockets at one face of the carrier and mating pins porjecting from the other face, so that any number of modules may be plugged together to create a stack of modules of any desired number of radiation lengths. The detector units each comprise four, preferably rectangular, p-i-n diode chips arranged around the associated feedthrough terminal to form a square detector unit providing at least 90% detector element coverage of the carrier.

Abstract: An apparatus for detecting radioactive contamination in hand-held objects, such as tools used to service a nuclear power facility, is disclosed herein. The apparatus generally comprises a radiation detector assembly having a gas-flow proportional detector, and a platform assembly formed from a perforated sheet of rigid material disposed over the topside of the detector for both supporting the hand-holdable objects and uniformly spacing the object from the detector. The radiation detector assembly is contained within a shielding cabinet having an access opening that is offset out of alignment with the top side of the detector for allowing an operator to deposit and withdraw an object onto and off of the platform. The walls of the shielding cabinet include pocket-like mounting assemblies for releasably holding one or more sheets of lead shielding material so that the amount of background radiation-reducing shielding may be advantageously adjusted.

Abstract: A detector for detecting the direction of incidence of ionized radiation comprises a laminated structure radiation detector which includes a plurality of planar structure detectors, each detector having a planar structure detector means constructed of a plurality of unit detectors arranged regularly on a plane and responsive to the ionized radiation. The planar detector further has position detector means which detects the position of the unit detector which has responded to ionized radiation. These planar structure detectors are arranged with a predetermined distance between them. The radiation detector further comprises direction of incidence calculating means for obtaining the direction of incidence of the ionized radiation from the outputs of the respective position detectors of the respective planar structure detectors.

Abstract: A .gamma. ray emitted from a reference radioactive ray source is radiated from outside to a solid radioactive waste. The radioactive intensity of the .gamma. ray emitted from the solid radioactive waste is measured during the radiation of the .gamma. ray. The radioactive intensity to be measured is discriminated into the first radiation intensity based on the reference radioactive ray source and the second radiation intensity based on the radioactive nuclide of the solid radioactive waste. A radiation absorption coefficient of the solid radioactive waste is determined based on the first radiation intensity. The distribution of radioactivity of the solid radioactive waste is determined based on the radiation absorption coefficient and the second radiation intensity.

Abstract: A diagnostic whole body counter includes both a detector for external or beta radiation and a detector for internal or gamma radiation. A subject stands on a platform and external radiation detectors inset in a back wall of the radiation detector are employed to quickly check for any external radiation on the subject. After it is determined that no external radiation is present, the subject is scanned using an internal radiation detector which is transported vertically along the length of the subject. An intrinsic germanium detector is employed as the internal radiation detector to provide a highly accurate determination of radiation dosage. Variable diameter lead collimators are positioned in front of the internal radiation detector to vary the size of the area scanned by the internal radiation detector.

Abstract: This invention provides a direct reading solid-state dosimeter which will measure neutron and gamma radiation. A dual metal-oxide-semiconductor field-effect transistor (MOSFET) is used as a gamma sensor and a forward biased PIN diode as a neutron sensor. A liquid crystal display is provided for displaying the gamma and neutron radiation dosage.

Abstract: The apparatus for checking persons for radioactive contamination comprises two detector panels (1, 2), each of which is provided on one broadside with detectors. The two detector panels (1, 2) extend at an angle to each other and said angle has an apex which defines a vertical axis. Those broadsides of the detector panels which are provided with detectors face the space included by the detector panels. Adjacent detectors of each detector panel are separated from each other by a vertical blank strip, which is so arranged relative to the contour of a reference figure (6) in a top plan view that the signals generated by the detector means which are separated by the blank strip (9, 10) can be processed to compensate the influence of the closest approximation of the reference figure to the detector panel on the generation of said signals. Adjacent detector means on each side of the vertical blank strip may be separated by a horizontal blank strip. The apparatus may be provided with underarm boxes.

Abstract: An apparatus for checking persons for radioactive contamination comprises at least two detector panels (1, 2), which are interconnected and extend at an angle to each other and are provided each with detectors on at least one broadside. Said detector panels define a space for accommodating a person to be checked. The apex of the angle defines a vertical axis of rotation for the detector panels, which are interconnected to form a subassembly. Resetting drive means are disposed between the axis of rotation and the rigid subassembly. A revolving door is provided in a lock chamber for checking persons for radioactive contamination. A tread surface is provided by a floor plate carrying a foot detector, which is disposed between the vertical detector panels when they are in position of rest.