Abstract: A radiation detector using gas amplification includes: a first electrode pattern which is formed on a first surface of an insulating member and has a plurality of circular openings; and a second electrode pattern which is formed on a second surface of the insulating member opposite to the first surface thereof and has convex portions of which respective forefronts are exposed to centers of the openings of the first electrode pattern; wherein a predetermined electric potential is set between the first electrode pattern and the second electrode pattern; wherein edges of the first electrode pattern exposing to the openings are shaped in respective continuous first curved surfaces by covering the edges thereof with a first solder material.

Abstract: A position-sensitive radiation counting detector includes a first and a second substrate. A gas is contained within the gap between the substrates. A photocathode layer is coupled to the first substrate and faces the second substrate. A first electrode is coupled to the second substrate and a second electrode is electrically coupled to the first electrode. A first impedance is coupled to the first electrode and a power supply is coupled to at least one electrode. A first discharge event detector is coupled to one of the electrodes for detecting a gas discharge event in the electrode. The radiation counting detector further includes a plurality of pixels, each capable of outputting a gas discharge counting event pulse upon interaction with radiation received from the photocathode. Each gas discharge pulse is counted as having an approximately equal value.

Abstract: A neutron detector that includes an anode and a cathode. The cathode includes at least one portion that has a porous substrate with surface segments that define open pores and a layer of neutron sensitive material on the surface segments of the porous substrate.

Abstract: The readout electrode assembly of an avalanche particle detector can be effectively protected against sparks and discharges by means of a plurality of resistor pads formed in a dielectric cover layer above the readout pads. The resistor pads may either be connected directly to the readout pads, or may be coupled capacitively by means of a charge spreading pad embedded into the dielectric cover layer and spatially separated from the readout pads. The charge spreading pad allows the distribution of charges to neighboring readout pads, and may hence increase the spatial resolution of the detector device.

Abstract: A device to measure the beam spot of a particle beam, has a device that records the projections of the beam spot in many directions that are essentially perpendicular to the direction of the particle beam, and an analysis device that reconstructs a two-dimensional cross section profile of the particle beam from the recorded projections.

Abstract: Nested ionization chambers provide independent measurements of a radiation beam that does not fully irradiate the volume of one or both chambers. By mathematically combining these independent measurements, partial volume effects caused by a change in ionization detector calibrations when the full detector volume is not irradiated by the radiation beam, may be decreased, providing more accurate measurement of extremely small radiation beams.

Abstract: A system may include a conductive substrate, a plurality of conductive nanostructures disposed on a first side of the conductive substrate, an insulating substrate, and a plurality of electrodes disposed on a first side of the insulating substrate. The first side of the conductive substrate faces the first side of the insulating substrate, and each of the plurality of electrodes is electrically connected to the conductive substrate. In other aspects, a system may include a first insulating substrate and a second insulating substrate, where a first side of the first insulating substrate faces a first side of the second insulating substrate, and each of a first plurality of electrodes is electrically connected to a respective one of a second plurality of electrodes.

Abstract: An ionizing radiation detector has conductive tubes arranged in parallel and containing a pressurized gas mixture, a conductive wire being pulled tight at the center of each tube and capable of being biased with respect thereto. Each tube is divided into isolated longitudinal sections. All the tube sections of a same transverse slice are electrically connected. Each group of sections of a same slice includes means for being connected to an elementary detector, wherein each slice is formed of a grid of blades.

Abstract: A gamma ray generator includes an ion source in a first chamber. A second chamber is configured co-axially around the first chamber at a lower second pressure. Co-axially arranged plasma apertures separate the two chambers and provide for restricted passage of ions and gas from the first to the second chamber. The second chamber is formed by a puller electrode having at least one long channel aperture to draw ions from the first chamber when the puller electrode is subject to an appropriate applied potential. A plurality of electrodes rings in the third chamber in third pressure co-axially surround the puller electrode and have at least one channel corresponding to the at least one puller electrode aperture and plasma aperture. The electrode rings increase the energy of the ions to a selected energy in stages in passing between successive pairs of the electrodes by application of an accelerating voltage to the successive pairs of accelerator electrodes.

Abstract: An object of the present invention is to provide a microchannel plate having excellent characteristics which enable to attain both high luminance and high resolution at the same time, a gas proportional counter using such a microchannel plate and an imaging device. The microchannel plate according to the present invention comprises a base body provided with a plurality of through holes (13) and having an insulating property, and is arranged in a gas atmosphere mainly containing an inert gas to constitute a proportional counter. The base body has photoelectric converter portions (1a, 1b) formed on at least inner walls of the plurality of through holes (13).

Abstract: A radiation counting detector includes a first substrate and a second substrate that is generally parallel to the first substrate and forms a gap with the first substrate. A gas is contained within the gap. A photocathode layer is coupled to one side of the first substrate and faces the second substrate. A first electrode is coupled to the second substrate and a second electrode is electrically coupled to the first electrode. A first impedance is coupled to the first electrode and a second impedance is coupled to the second electrode. A power supply is coupled to at least one of the electrodes. The radiation counting detector further includes a plurality of pixels, each capable of outputting a gas discharge pulse upon interaction with radiation received from the photocathode. Each gas discharge pulse is counted as having an approximately equal value.

Abstract: An electron generating device extracts electrons, through an electron sheath, from plasma produced using RF fields. The electron sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted electrons pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the plasma allow for helicon plasma generation. The ion loss area is sufficiently large compared to the electron loss area to allow for total non-ambipolar extraction of all electrons leaving the plasma. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the plasma within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the plasma.

Abstract: The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

Abstract: A charge-coupled device includes a photosensitive region for collecting charge in response to incident light; a first and third gate electrode made of a transmissive material spanning at least a portion of the photosensitive region; and a second gate electrode made of a transmissive material that is less transmissive than the first and third gates and spans at least a portion of the photosensitive region; wherein the first, second and third gates are arranged symmetrically within an area that spans the photosensitive region.

Abstract: A data processing device, comprising a plurality of emitter antennas arranged on a movable data acquisition device and adapted to emit electromagnetic radiation including data acquired by the movable data acquisition device, a plurality of receiver antennas each adapted to receive the electromagnetic radiation emitted by each of the plurality of emitter antennas, and a data processing unit coupled to the plurality of receiver antennas and adapted to extract the data acquired by the movable data acquisition device from the electromagnetic radiation received by the plurality of receiver antennas.

Abstract: A radiation detection device comprising a plasma display panel (PDP) with a multiplicity of radiation detection pixels, each radiation detection pixel being defined by a hollow elongated Plasma-tube filled with an ionizable gas. Arrays of Plasma-tubes are positioned on a suitable base such as a substrate and used to inspect and detect radiation from a selected object. Each Plasma-tube may be of any suitable geometric configuration and may be used alone or in any combination with one or more Plasma-shells, such as a Plasma-disc, Plasma-dome, and/or Plasma-sphere. Luminescent material may be positioned near or on each Plasma-tube or Plasma-shell to provide or enhance light output. A flexible base substrate may be used to wrap a layer or blanket of radiation detection Plasma-tubes about the selected object. The substrate base may comprise an elongated rod that is used as a probe to detect radiation from an object. An object may be passed through a ring or a cylinder of Plasma-tubes.

Abstract: A radiation counting detector includes a first substrate and a second substrate that is generally parallel to first substrate and forms a gap with the first substrate. A gas is contained within the gap. A photocathode layer is coupled to one side of the first substrate and faces the second substrate. A first electrode is coupled to the second substrate and a second electrode is electrically coupled to the first electrode. A first impedance is coupled to the first electrode and a second impedance is coupled to the second electrode. A power supply is coupled to at least one of the electrodes. A first discharge event detector is coupled to the first impedance and a second discharge event detector is coupled to the second impedance. The radiation counting detector further includes a plurality of pixels, each capable of outputting a gas discharge pulse upon interaction with radiation received from the photocathode. Each gas discharge pulse is counted as having an approximately equal value.

Abstract: A high strength window for a radiation detection system includes a plurality of intersecting ribs defining a grid having openings therein with tops of the ribs terminate substantially in a common plane. The intersecting ribs are oriented non-perpendicularly with respect to each other and define non-rectangular openings. The window also includes a support frame around a perimeter of the plurality of intersecting ribs, and a film disposed over and spanning the plurality of intersecting ribs and openings. The film is configured to pass radiation therethrough. An associated radiation detection system includes a sensor disposed behind the window. The sensor is configured to detect radiation passing through the high strength window.

Abstract: A micro-sized gas detecting device with two electrodes separated by a gap of width ranging from 1 to 500 microns, where the detection is based on emission spectroscopy of gases in an electric discharge across the gap (discharge region) as the gas flows through the region. The characteristic light emitted by molecules during the discharge can be detected directly with photodiodes or transferred through optical fiber and detected with remote optical sensing components. The device can have single or multiple discharge regions in an array so that light emitted can be monitored at different wavelengths simultaneously. The device can operate under gaseous pressure ranging from a few milli-Torr to a few atmospheres. The device consumes little power (50 mW-100 mW) and can be powered with an alternating current and has the potential to be battery powered.

Abstract: A radiation counting detector includes a first and a second substrate. A gas is contained within the gap between the substrates. A photocathode layer is coupled to one side of the first substrate and faces the second substrate. A first electrode is coupled to the second substrate and a second electrode is electrically coupled to the first electrode. A first impedance is coupled to the first electrode and a second impedance is coupled to the second electrode. A power supply is coupled to at least one electrode. A first discharge event detector is coupled to the first impedance and a second discharge event detector is coupled to the second impedance. The radiation counting detector further includes a plurality of pixels, each capable of outputting a gas discharge pulse upon interaction with radiation received from the photocathode. Each gas discharge pulse is counted as an individual event having an approximately equal value.

Abstract: The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

Abstract: Method and apparatus is provided for monitoring an item for radioactive material on or associated with the item, the apparatus including an enclosed volume, an item monitoring location, a detection location, ion detectors provided within the detection location, a mover of gas for providing a flow of gas past the item monitoring location to a detection location, so as to revel the level and/or presence of radioactive material on the item. The item may be supported within the monitoring location by one or more rollers to ease its insertion and/or removal. The item monitoring location may be extremely elongate so as to measure pipes and the like. Various designs of roller and gas flow controllers are provided to optimize monitoring.

Abstract: The invention relates to a detector for detecting electrically neutral particles. The detector has a housing (10) filled with a counting gas. A converter (22) in the housing (10) generates conversion products as a result of the absorption of the neutral particles. The conversion products generate electrically charged particles in the counting gas, and a readout device (19) detects the electrically charged particles. A device (18) generates an electrical drift field for the electrically charged particles in a region of the volume of the counting gas so that at least some of the electrically charged particles drift toward the readout device (19). The converter device (22) is of charge-transparent design and being arranged in the detector housing (10) so that the drift field passes through at least part of this device.

Abstract: A plasma panel based ionizing-photon radiation detector includes an input and output substrate with gamma-ray to free-electron conversion occurring primarily on the input plate and a sealed discharge gas between the substrates. X-electrodes and Y-electrodes are formed on the two substrates and configured to form a plurality of pixels. Impedances are coupled to the X and Y electrodes and a power supply is coupled to the X-electrodes. Discharge event detectors coupled to impedances detect discharge events on the Y electrodes and at the pixel locations, which leads to the detection of ionizing-photon radiation.

Abstract: A plasma panel based ionizing-photon radiation detector includes an input and output substrate with gamma-ray to free-electron conversion occurring primarily on the input plate and a sealed discharge gas between the substrates. X-electrodes and Y-electrodes are formed on the two substrates and configured to form a plurality of pixels. Impedances are coupled to the X and Y electrodes and a power supply is coupled to the X-electrodes. Discharge event detectors coupled to impedances detect discharge events on the Y electrodes and at the pixel locations, which leads to the detection of ionizing-photon radiation.

Abstract: A nuclear radiation detector is disclosed wherein the capacitance of the detector is significantly reduced. This improvement results in more efficient and accurate measurements of radiative entities. The design also permits greater packing density in applications requiring large arrays of radiation detectors, such as would be needed in the monitoring systems of nuclear power plants. Moreover, the disclosed design reduces costs associated with detector arrays by enabling neighboring elements to share critical components.

Abstract: An infrared (IR) radiation detector adapted to detect IR radiation by measuring pneumatic expansion of a sense chamber that is caused by a temperature increase within that chamber due to the absorbed energy of the IR radiation. A reference chamber mechanically coupled to the sense chamber controls the pneumatic expansion of the sense-chamber. The expansion is detected either electrically or optically.

Abstract: A radiation monitor and method of monitoring the radiation delivered to a target by a radiation device is described. The radiation monitor contains a set or matrix of pixel ion chambers. The pixel ion chambers are preferably constructed of a top electrode and a segmented electrode connected to the top electrode through a mid layer. The plurality of pixel ion chambers is formed within the mid layer extending from the top electrode to the segmented electrode. The mid layer is laminated to the top electrode and segmented electrode by an array of adhesive dots, wherein the adhesive dots are dimensioned and positioned on the mid layer to provide ventilation slits or channels for the ion chambers.

Abstract: An instrument for checking quality of therapeutic x-ray and electron radiation provides modes optimized for both electrons and for photons obtained by physically flipping the unit to interpose the necessary build-up material between the radiation beam and contained detectors. The invention provides an improved method of constructing ionization detectors for improved energy discrimination using such detectors and wire-free operation.

Abstract: In a preferred embodiment, a radiation detector, including: one or more anode wires disposed within a body of the radiation detector, connections to and suspension of the one or more anode wires being made externally of active volume of said radiation detector.

Abstract: The invention relates to a cassette, in particular an X-ray cassette, for receiving a storage fluorescent screen. The cassette has on one of its narrow sides an opening through which the storage fluorescent screen is to be inserted into or removed from the cassette. The opening is closable by a flap which is displaceable between a closed position in which it closes the opening and a release position in which it releases the opening for insertion or removal of the storage fluorescent screen. For this purpose the flap is mounted swivellably to the transition between the narrow side of the cassette provided with the opening and the base of the cassette or the cassette lid.

Abstract: An infrared (IR) radiation detector adapted to detect IR radiation by measuring pneumatic expansion of a sense chamber that is caused by a temperature increase within that chamber due to the absorbed energy of the IR radiation. A reference chamber mechanically coupled to the sense chamber controls the pneumatic expansion of the sense-chamber. The expansion is detected either electrically or optically.

Abstract: A nuclear radiation detector is disclosed wherein the capacitance of the detector is significantly reduced. This improvement results in more efficient and accurate measurements of radiative entities. The design also permits greater packing density in applications requiring large arrays of radiation detectors, such as would be needed in the monitoring systems of nuclear power plants. Moreover, the disclosed design reduces costs associated with detector arrays by enabling neighboring elements to share critical components.

Abstract: A radiation detection device comprising a plasma display panel (PDP) with a multiplicity of radiation detection pixels, each radiation detection pixel being defined by a hollow gas filled Plasma-shell having one or more flat sides. Arrays of Plasma-shells are positioned on a suitable base such as a substrate and used to inspect and detect radiation from a selected object. Each Plasma-shell may be of any suitable geometric configuration, including a Plasma-disc and a Plasma-dome. Luminescent material may be positioned near or on each Plasma-shell to provide or enhance light output. A flexible base substrate may be used to wrap a layer or blanket of radiation detection Plasma-shells about the selected object.

Abstract: A penetration ionization chamber includes a chamber, two outer electrode plates and a center electrode plate. The center electrode plate is disposed at the center of the chamber, and signals produced in the chamber can be collected completely by the center electrode plate to avoid signal losses and improve the accuracy of the test result of the ionization chamber. The center electrode plate also can maintain a constant internal volume of the chamber and prevent a change of effective volume within the chamber due to a change of electric field and enhance the stability of the test result of the ionization chamber. A protection electrode is wrapped by an insulation pin of the electrode and the outer insulation ring to form an insulation shield that can greatly reduce current leakage of the protection electrode and improve the accuracy of the test result of the ionization chamber.

Abstract: Electrodes for detecting the position of an incident particle are formed by a global position detection electrode for detecting the global position of the incident particle and a plurality of local position detection electrodes for detecting the local position of the incident particle. The position of the incident particle is identified from the global position information detected by the global position detection electrode and the local position information detected by the local position detection electrodes. A plurality of local position detection electrodes are divided into a plurality of groups and local position detection electrodes belonging to each group are connected to a common signal line. A predetermined number of local position detection electrodes correspond to one global position and the predetermined number of local position detection electrodes corresponding to one global position belong to different groups.

Abstract: An instrument for checking quality of therapeutic x-ray and electron radiation provides modes optimized for both electrons and for photons obtained by physically flipping the unit to interpose the necessary build-up material between the radiation beam and contained detectors. The invention provides an improved method of constructing ionization detectors for improved energy discrimination using such detectors and wire-free operation.

Abstract: Microfabricated, gas-filled radiation detector assemblies, methods of making and using same and interface circuit for use therewith are provided. The assembly includes a micromachined radiation detector including a set of spaced-apart electrodes and an ionization gas between the electrodes. A housing has a chamber for housing the detector including the gas. The housing of the assembly also includes a window which allows passage of charged particles therethrough to ionize the gas to create electrons which, in turn, create an electron cascade in the gas between the electrodes when the set of electrodes is biased.

Abstract: Apparatus for the inspection of cargo containers for nuclear materials comprising one or more arrays of modules comprising grounded, closed conductive tubes filled with an ionizing gas mixture such as, but not limited to, Argon:CO2. A wire is suspended along each tube axis and electrically connected at both ends of the tube. A positive, dc high voltage is supplied to one end of the wire and an amplifier is attached to the other end through a capacitance to decouple the amplifier from the high voltage. X-rays, gamma rays or neutrons produced by nuclear material and passing through the tube ionize the gas. The electrons from the gas ionization process are accelerated toward the wire surface due to the wire's electrical potential. The acceleration of the electrons near the wire's surface is sufficient to ionize more gas and produce an amplification of electrons/ions that create a surge of current large enough to be detectable by the amplifier.

Abstract: A method for the detection of ionizing radiation including directing ionizing radiation towards an object to be examined, preventing Compton scattered radiation from being detected, and detecting ionizing radiation spatially resolved as transmitted through the object to reveal a spatially resolved density of the object. The ionizing radiation is provided within a spectral range such that more photons of the ionizing radiation are Compton scattered than absorbed through the photoelectric effect in the object, thereby reducing the radiation dose to the to the object.

Abstract: A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. A conductive neutron-capturing layer is disposed on the interior surface of the cathode and a plastic housing surrounds the cathode. A plastic lid is attached to the housing and encloses the interior volume of the cathode forming an ionization chamber, into the center of which an anode extends from the plastic lid. A working gas is disposed within the ionization chamber and a high biasing voltage is connected to the cathode. Processing electronics are coupled to the anode and process current pulses which are converted into Gaussian pulses, which are either counted as neutrons or integrated as gammas, in response to whether pulse amplitude crosses a neutron threshold. The detector according to the invention may be readily fabricated into single or multilayer detector arrays.

Abstract: A new design for a cylindrical ionization detector, featuring a resistive cathode, and external pickup wires that sense both the azimuthal and radial coordinates of interaction vertices. Combined with measurement of the longitudinal coordinate (using resistive anode wire charge division or other technique), the proposed design can provide an accurate 3-dimensional imaging detector and offer improved spectroscopic response.

Abstract: In detectors for imaging and other applications, delay line anodes are arrayed so as to allow detection of the location and/or timing of particle hits. The anodes are arrayed to provide an upper anode and one or more lower anodes, with particles incident on the upper anode passing in turn to the lower anodes. The anode arrays allow the use of identically manufactured anodes which are maintained in parallel spaced relation along the travel path of the particles of interest without dielectric material or other structure situated between the anodes. The spacing between the anodes is preferably adjustable so as to allow the installer and/or user to modify the performance characteristics of the array. The anodes may be made of pre-formed metal foil signal and ground layers laminated onto opposing sides of a dielectric sheet, or may be etched or otherwise formed from flex circuit material, so that the anodes and the overall array are light weight, compact, and flexible.

Abstract: The present invention relates to a microstrip gas chamber and microstrip plate capable of reading signals from readout electrodes provided at a rear surface of the substrate in a superior manner while having a simple and compact configuration. The microstrip plate comprises an electrically insulating substrate 1, cathodes 2 and anodes 3 arranged alternately at the surface of the substrate 1, read-out electrodes 4 arranged so as to intersect the cathodes 2 and anodes 3 at the rear surface of the substrate 1, wherein a plurality of unitary regions 20 are provided at the surface of the substrate 1 and each unitary region 20 is electrically floated from the cathode via a resistance region 5.

Abstract: An ionizing radiation detector comprising a plurality of conductive tubes arranged in parallel fashion containing a gas mixture under pressure, a conductive wire being tensed at the center of each tube and adapted to being polarized with respect thereto, and comprising first and second tight enclosures each having a wall provided with openings in which are tightly inserted the first and second ends of each tube, the ends of each tube being open.

Abstract: Two-dimensional detector of ionizing radiation and process for manufacturing this detector This detector comprises sheets (4) emitting particles by interaction with ionizing radiation, semiconducting layers (6) that alternate with the sheets and can be ionized by the particles, and groups of conducting tracks (22) in contact with the layers. Means (26) of creating an electric field are used to collect charge carriers generated in the layers due to interaction with particles, through the tracks. For example, the layer and the corresponding tracks are formed on each sheet and the sheets are then assembled together. For example, the invention is applicable to radiography and can achieve good X-ray detection efficiency and high spatial resolution at the same time.

Abstract: An apparatus for detecting X-rays comprises a scintillator which emits a plurality of photoelectrons upon being impacted by an X-ray photon. The photoelectrons are amplified in a gas electron multiplier and the resultant photoelectrons are accumulated on a two dimensional array of charge collection electrodes. Electrical signals are produced which indicate the quantity of photoelectrons which strike each charge collection electrode. A processor determines a location of the X-ray photon strike by analyzing the spatial distribution of the photoelectrons accumulated by the array of charge collection electrodes. The intensity of the X-ray photon is determined from the number of accumulated photoelectrons.

Abstract: A particle beam image detector employing gas amplification attained by pixel-type electrodes has high sensitivity and improved reliability of electrodes. Electrons e− produced through ionization of the gas move under the force of a drift field toward a pixel in the form of a columnar anode electrode. Avalanche amplification occurs in the vicinity of the columnar anode electrode due to a strong electric field between anode and cathode and the pointed shape of the electrode. The positive ions quickly drift toward strip-shaped cathode electrodes. Electric charges are generated on the columnar anode electrodes and also on the strip-shaped cathodes and these electric charges are observable to determine the anode or cathode strip at which this amplification phenomenon occurs and thus to obtain information as to position of the incident particle beam.

Abstract: A radiation detector comprises two electrode arrangements, each including a dielectric substrate and an electrically conducting layer formed on a first surface of respective dielectric substrate, wherein the electrodes are oriented such that the conducting layers are facing each other. A dielectric spacer is provided to hold the electrodes at a distance from each other to thereby define an inter-electrode space, which, during use, is filled with an ionizable gas. The electrodes are held at respective electric potentials to drift electrons released during ionization of the ionizable gas by external radiation towards one of the electrodes for detection.

Abstract: A scanning-based radiation detector arrangement for two-dimensional imaging of an object comprises a plurality of one-dimensional detector units, each comprising an entrance slit, through which ionizing radiation as transmitted through the object is entered, and being arranged for one-dimensional imaging of the ionizing radiation, wherein the detector units are arranged in an array on a support with their respective entrance slits being parallel with each other and facing the source of the ionizing radiation. The detector arrangement further includes a rotating device for rotating the detector unit array in a plane perpendicular to the direction of the ionizing radiation, while the detector units are arranged to repeatedly detect, hence creating a series of two-dimensional images of the object.