Abstract: A method of identifying radioactive components in a source comprising (a) obtaining a gamma-ray spectrum from the source; (b) identifying peaks in the gamma-ray spectrum; (c) determining an array of peak energies and peak intensities from the identified peaks; (d) identifying an initial source component based on a comparison of the peak energies with a database of spectral data for radioactive isotopes of interest; (e) estimating a contribution of the initial source component to the peak intensities; (f) modifying the array of peak energies and peak intensities by subtracting the estimated contribution of the initial source component; and (g) identifying a further source component based on a comparison of the modified array of peak energies with the database of spectral data. Thus a method for identifying radioactive components in a source is provided which does not rely on comparing template spectra with an observed spectrum.

Abstract: New sensors, pixel detectors and different embodiments of multi-channel integrated circuit are disclosed. The new high energy and spatial resolution sensors use solid state detectors. Each channel or pixel of the readout chip employs low noise preamplifier at its input followed by other circuitry. The different embodiments of the sensors, detectors and the integrated circuit are designed to produce high energy and/or spatial resolution two-dimensional and three-dimensional imaging for different applications. Some of these applications may require fast data acquisition, some others may need ultra high energy resolution, and a separate portion may require very high contrast. The embodiments described herein addresses these issues and also other issues that may be useful in two and three dimensional medical and industrial imaging.

Abstract: A semiconductor radiation detector (1?, 1?, 1??, 1??) includes a body of semiconducting material (2) responsive to ionizing radiation for generating electron-hole pairs in the bulk of said body (2). A conductive cathode (4) is disposed on one side of the body (2) and an anode structure (6) is disposed on the other side of the body (2). The anode structure (6) includes a first set of spaced elongated conductive fingers (8) in contact with the body (2) and defining between each pair of fingers thereof an elongated gap (10) and a second set of spaced elongated conductive fingers (12) positioned above the surface of the body (2) that includes spaced elongated conductive fingers (8). Each finger of the second set of spaced elongated conductive fingers (12) overlays, either partially or wholly, the elongated gap between a pair of adjacent fingers of the first set of spaced elongated conductive fingers (8).

Abstract: A radiation detection device, including a detector in semi-conductor material, a first electrode, and a second electrode. The first electrode has a form of pixels, with a first pitch, on one of the sides of the detector. The device further includes a mechanism for identifying the energy of an incident photon in the detector as a function of signals coming uniquely from the second electrode.

Abstract: A CdZnTe photon counting detector includes a core material of Cd1-xZnxTe, where (0?x<1), an anode terminal on one side of the core material and a cathode terminal on a side of the core material opposite the anode terminal. At least one of the following is selected in the design of the detector as a function of the maximum sustainable photon flux the core material is able to absorb in operation while avoiding polarization of the core material: electron lifetime-mobility product of the core material; de-trapping time of the core material; a value of a DC bias voltage applied between the anode and the cathode; a temperature of the core material in operation; a mean photon flux density to be absorbed by the core material in operation; and a thickness of the core material between the anode and the cathode.

Abstract: A direct radiation converter is disclosed. In at least one embodiment, the direct radiation converter is operated using a direct conversion element having a temperature of at least 38° C. and at most 55° C., and designed for detecting X-ray radiation.

Abstract: A method of forming a passivation layer comprises contacting at least one surface of a wide band-gap semiconductor material with a passivating agent comprising an alkali hypochloride to form the passivation layer on said at least one surface. The passivation layer may be encapsulated with a layer of encapsulation material.

Abstract: A device includes (a) radiation detector including a semiconductor substrate having opposing front and rear surfaces, a cathode electrode located on the front surface of said semiconductor substrate, and a plurality of anode electrodes on the rear surface of said semiconductor substrate, (b) a printed circuit board, and (c) an electrically conductive polymeric film disposed between circuit board and the anode electrodes. The polymeric film contains electrically conductive wires. The film bonds and electrically connects the printed circuit board and anode electrodes.

Abstract: A system for combining the spectral data from multiple ionizing radiation detectors of different types and having different photopeak energy resolutions. First, baseline estimation is performed on each spectral histogram separately, discerning peak regions from underlying continuum using respective peak response functions. All spectra are subsequently rebinned to the same energy calibration and the peak spectra are convolved to produce a single convolution spectrum. All peak counts are redistributed locally according to the convolution spectrum in energy regions proportional to respective local energy resolution. The summation of these redistributed peak spectra can then be analyzed as a single spectrum using a common photopeak response and energy calibration. This process can be embodied in software or firmware. A preferred hybrid system might include a combination of lower resolution, higher efficiency detectors and higher resolution, lower efficiency detectors.

Abstract: The invention provides methods and apparatus for detecting radiation including x-ray, gamma ray, and particle radiation for nuclear medicine, radiographic imaging, material composition analysis, high energy physics, container inspection, mine detection and astronomy. The invention provides detection systems employing one or more detector modules (102) comprising edge-on scintillator detectors (101) with sub-aperture resolution (SAR) capability employed, e.g., in nuclear medicine, such as radiation therapy portal imaging, nuclear remediation, mine detection, container inspection, and high energy physics and astronomy. The invention also provides edge-on imaging probe detectors for use in nuclear medicine, such as radiation therapy portal imaging, or for use in nuclear remediation, mine detection, container inspection, and high energy physics and astronomy.

Abstract: In one embodiment, a system comprises a semiconductor gamma detector material and a hole blocking layer adjacent the gamma detector material, the hole blocking layer resisting passage of holes therethrough. In another embodiment, a system comprises a semiconductor gamma detector material, and an electron blocking layer adjacent the gamma detector material, the electron blocking layer resisting passage of electrons therethrough, wherein the electron blocking layer comprises undoped HgCdTe. In another embodiment, a method comprises forming a hole blocking layer adjacent a semiconductor gamma detector material, the hole blocking layer resisting passage of holes therethrough. Additional systems and methods are also presented.

Abstract: A radiation detector crystal is made from CdxZn1-xTe, where 0?x?1; an element from column III or column VII of the periodic table, desirably in a concentration of about 1 to 10,000 atomic parts per billion; and the element Ruthenium (Ru), the element Osmium (Os) or the combination of Ru and Os, desirably in a concentration of about 1 to 10,000 atomic parts per billion using a conventional crystal growth method, such as, for example, the Bridgman method, the gradient freeze method, the electro-dynamic gradient freeze method, the so-call traveling heater method or by the vapor phase transport method. The crystal can be used as the radiation detecting element of a radiation detection device configured to detect and process, without limitation, X-ray and Gamma ray radiation events.

Abstract: A radiological measurement system protecting an amplifier from damage caused by a surge current, ensuring temporal continuity of measurement with a minimum dead time, and including a high voltage DC supply for applying a bias voltage to a radiation detector formed of semiconductor crystal, a controller for exercising on-off control on the bias voltage supplied from the high voltage DC supply, an amplifier, a protection circuit for protecting the amplifier from a surge current generated when the bias voltage is subjected to the on-off control, a control unit for preventing the surge current from flowing to the amplifier, and a switch provided in parallel with the protection circuit and controlled in operation state by the control unit, wherein the control unit controls the operation state of the switch in synchronism with the on-off control exercised by the control unit to prevent the surge current from flowing to the amplifier.

Abstract: A semiconductor radiation detector (1?, 1?, 1??, 1??) includes a body of semiconducting material (2) responsive to ionizing radiation for generating electron-hole pairs in the bulk of said body (2). A conductive cathode (4) is disposed on one side of the body (2) and an anode structure (6) is disposed on the other side of the body (2). The anode structure (6) includes a first set of spaced elongated conductive fingers (8) in contact with the body (2) and defining between each pair of fingers thereof an elongated gap (10) and a second set of spaced elongated conductive fingers (12) positioned above the surface of the body (2) that includes spaced elongated conductive fingers (8). Each finger of the second set of spaced elongated conductive fingers (12) overlays, either partially or wholly, the elongated gap between a pair of adjacent fingers of the first set of spaced elongated conductive fingers (8).

Abstract: A radiation detector is described having a semiconductor substrate with opposing front and rear surfaces, a cathode electrode located on the front surface of said semiconductor substrate, a plurality of anode electrodes located on the rear surface of said semiconductor substrate and a solder mask disposed above the anode electrodes. The solder mask has openings extending to the anode electrodes for placing solder in said openings.

Abstract: A method of detecting ionizing radiation is provided.

Abstract: A radiological imaging apparatus using a semiconductor radiation detector to make it possible to reduce a radiation measurement off time that may result from an attempt to avoid polarization, the radiological imaging apparatus comprising a capacitor that applies a voltage to a semiconductor radiation detector that detects a radiation from a subject, first current regulated means for conducting a charge current to the capacitor, and second current regulated means for conducting a discharge current from the capacitor, or comprising a capacitor that applies a voltage to the semiconductor radiation detector, a first resistor that conducts a charge current to and a discharge current from the capacitor, and a second resistor connected in parallel with the first resistor to subject the capacitor to charging and discharging.

Abstract: Disclosed herein is a computed tomography (CT) detector module, for coupling with a collimator rail. The CT detector module includes a CT detector pack, a printed circuit board, and electrical conductor, and a substrate. The electrical conductor is disposed between and in electrical communication with the CT detector pack and the printed circuit board. The substrate has a slot and is disposed between the CT detector pack and the circuit board such that the electrical conductor is routed through the slot.

Abstract: An X-ray detector for detecting X rays includes a semiconductor for generating electric charges therein upon X-ray incidence, and electrodes formed on opposite sides of the semiconductor for application of a predetermined bias voltage. The semiconductor is amorphous selenium (a-Se) doped with a predetermined quantity of an alkali metal.

Abstract: The present invention provides an orofacial radiation detection device for detection of radionuclide contamination from inhalation. The device includes a face mask including a support frame and an adjustable head strap connected to the support frame. Mounted on the frame are radiation detectors in selected locations so that when being worn by a person, the detectors are located in close proximity to the orofacial region of the person including their nose and mouth. The device includes an electronic controller connected to the detectors for controlling operation of the radiation detectors. The device includes a microcomputer mounted on the support frame and electrically connected to the electronic controller for processing signals from the detectors for allowing input from an operator, performing data analysis and detection algorithms, and outputting results.

Abstract: A system in one embodiment includes an array of radiation detectors; and an array of imagers positioned behind the array of detectors relative to an expected trajectory of incoming radiation. A method in another embodiment includes detecting incoming radiation with an array of radiation detectors; detecting the incoming radiation with an array of imagers positioned behind the array of detectors relative to a trajectory of the incoming radiation; and performing at least one of Compton imaging using at least the imagers and coded aperture imaging using at least the imagers. A method in yet another embodiment includes detecting incoming radiation with an array of imagers positioned behind an array of detectors relative to a trajectory of the incoming radiation; and performing Compton imaging using at least the imagers.

Abstract: A method for the detection of ionizing events utilizing a co-planar grids sensor comprising a semiconductor substrate, cathode electrode, collecting grid and non-collecting grid. The semiconductor substrate is sensitive to ionizing radiation. A voltage less than 0 Volts is applied to the cathode electrode. A voltage greater than the voltage applied to the cathode is applied to the non-collecting grid. A voltage greater than the voltage applied to the non-collecting grid is applied to the collecting grid. The collecting grid and the non-collecting grid are summed and subtracted creating a sum and difference respectively. The difference and sum are divided creating a ratio. A gain coefficient factor for each depth (distance between the ionizing event and the collecting grid) is determined, whereby the difference between the collecting electrode and the non-collecting electrode multiplied by the corresponding gain coefficient is the depth corrected energy of an ionizing event.

Abstract: A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C.

Abstract: A CdTe or CdZnTe radiation imaging detector and high voltage bias part for applying a high voltage to the continuous electrode to ensure stable performance of the detector. The high voltage bias part includes conductors of >30 um diameter and preferably selected from a group of materials that do not oxidize easily or oxidize less than aluminium.

Abstract: A radiation detection system includes a radiation detector and a DC/DC converter that induces an electric field in the radiation detector. A counter circuit outputs a pulse related to the energy of each incoming radiation event on the radiation detector. The peak amplitude of each pulse output by the counter circuit is converted into a digital equivalent value. A means for processing processes each digital equivalent value and counts a number of pulses output by the counter circuit over an interval of time. A port has one or more data lines connected to the means for processing and one or more power lines connected to the DC/DC converter. The port facilitates a connection to a host system which provides a single DC voltage to the DC/DC converter which converts the single DC voltage into a higher level voltage that induces the electric field in the radiation detector.

Abstract: A radiological imaging apparatus using a semiconductor radiation detector to make it possible to reduce a radiation measurement off time that may result from an attempt to avoid polarization, the radiological imaging apparatus comprising a capacitor that applies a voltage to a semiconductor radiation detector that detects a radiation from a subject, first current regulated means for conducting a charge current to the capacitor, and second current regulated means for conducting a discharge current from the capacitor, or comprising a capacitor that applies a voltage to the semiconductor radiation detector, a first resistor that conducts a charge current to and a discharge current from the capacitor, and a second resistor connected in parallel with the first resistor to subject the capacitor to charging and discharging.

Abstract: A solid state ionizing radiation detector is provided, having an absorber within which, when in use, electrical charge is generated upon the absorption of ionizing radiation. The absorber has a front face with an active region through which incident ionizing radiation is received. A front electrode is located at the front face. A rear electrode substantially covers a rear face of the absorber. The front and rear electrodes are arranged in use to generate an electric field in the absorber so as to collect the generated electrical charge. The area of the rear face is substantially smaller than that of the active region of the front face. At least part of the absorber within which the electric field is generated is bounded by substantially smooth and substantially tapered sidewalls.

Abstract: A method and apparatus for reducing polarization within an imaging device are provided and include a method of controlling an image detecting device. The method includes applying heat to the image detecting device having at least one ohmic contact and controlling the applied heat to adjust a temperature level of the image detecting device.

Abstract: Described herein is a multi-colour radiation detector that comprises a mesa-type multi-layered mercury-cadmium-telluride detector structure (10) monolithically integrated on a substrate (6). The detector is responsive to three or more discrete wavelength ranges and means is provided whereby each of the wavelength ranges can be detected independently or in combination with others of the ranges.

Abstract: A method of detecting ionizing radiation is provided.

Abstract: The present invention provides a semiconductor radioactive ray detector having the excellent energy resolution or time precision, a radioactive detection module, and a nuclear medicine diagnosis apparatus. The semiconductor radioactive ray detector has a structure in which plate-like elements made of cadmium telluride and conductive members are alternately laminated and the plate-like element made of cadmium telluride and the conductive member are adhered to each other with a conductive adhesive agent, and the Young's modulus of the conductive adhesive agent is in the range from 350 MPa to 1000 MPa, while the conductive members are made from a material with the linear expansion coefficient of the conductive members in the range from 5×10?6/° C. to 7×10?6/° C.

Abstract: A method and apparatus for detecting gamma-rays is provided, wherein the gamma-ray detector apparatus includes a plurality of detector elements arranged in a stacked configuration. Each of the plurality of detector elements may include, a detector wafer having at least one anode separated from a cathode via a wafer material, wherein the wafer material includes a wafer material thickness d, and a wafer interface, wherein the wafer interface is electrically connected to the at least one anode.

Abstract: An industrial or medical radiation detector and a radiation imaging device equipped with the radiation detector are presented. The device improves the detection properties and production efficiency of the radiation detectors. The device includes a conductive support substrate; a semiconductor sensitivity film stacked onto the support substrate and generating a carrier (electron, positive hole) in response to an item to be detected; and means for reading equipped with an element for accumulating and reading the carrier generated by the semiconductor sensitivity film.

Abstract: A system reverses degraded energy resolution of semiconductor radiation detection elements (44) which are used in a radiation detector assembly. A means (38) identifies semiconductor elements which exhibit degraded energy resolution as compared to an initial level of energy resolution after application of the forward bias. A means (40) restores the degraded semiconductor elements to the initial level of energy resolution by applying the reverse bias. A heater (74) accelerates the restoration process by supplying an elevated ambient temperature. A screening means (48) screens new semiconductor elements to identify the elements which are susceptible to degradation. A forward bias is applied by a forward bias means (50) to induce the degradation. A heater (52) increases an ambient temperature to accelerate the performance degradation in the new semiconductor elements. The identified degradable elements are treated with a reverse bias prior to installation in the detector.

Abstract: A radiation detector is described having a semiconductor substrate with opposing front and rear surfaces, a cathode electrode located on the front surface of said semiconductor substrate, a plurality of anode electrodes located on the rear surface of said semiconductor substrate and a solder mask disposed above the anode electrodes. The solder mask has openings extending to the anode electrodes for placing solder in said openings.

Abstract: This is a processing circuit for a spectrometry chain including a particle radiation detector (21), including a charge preamplifier stage (20) receiving a current (I1) from the detector, representative of the amount of charges emitted by a particle which has interacted with the detector, and an integrator stage (26). A differentiator stage (25) is connected between the charge preamplifier stage (20) and the integrator stage (26), the differentiator stage (25) receiving a signal (V1) from the charge preamplifier stage (20) and delivering to the integrator stage (26), a signal (V2), image of the detector current (I1), the integrator stage (26) delivering, an image (V3) of the amount of charges emitted by a particle which has interacted with the detector. Application notably to the high energy single channel probes.

Abstract: A semiconductor radiation detector 10 comprises a Si substrate 11 of an N-ype of low resistance, an arsenic coating layer 12 formed on the Si substrate, and a CdTe growth layer 13 of a P-type of high resistance laminated and formed thereon by the MOVPE method, which is divided into multiple plane elements of a hetero junction structure by means of division grooves 15 extending from the CdTe growth layer surface to the Si substrate. The Si substrate is heated in a hydrogen reducing atmosphere of a high temperature, and its surface is cleaned. On this Si substrate, GaAs powder or GaAs crystals are thermally decomposed, and coated by arsenic molecule to an extent at about one molecular layer, and an arsenic coating layer is thereby formed. On the Si substrate forming the arsenic coating layer, a CdTe growth layer is formed by the MOVPE method to a film thickness of about 0.2 to 0.5 mm in an atmosphere of about 450 to 500 deg. C.

Abstract: Method and apparatus for sensing and acquiring radiation data comprises sensing radiation events with a multi-modality detector. The detector comprises solid state crystals forming a matrix of pixels which may be arranged in rows and columns, and has a radiation detection field for sensing radiation events. The radiation events for each pixel are counted by an electronic module attached to each pixel. The electronic module comprises a threshold analyzer for analyzing the radiation events. The threshold analyzer identifies valid events by comparing an energy level associated with the radiation event to a predetermined threshold. The electronic module further comprises at least a first counter for counting the valid events.

Abstract: A radiation detector provided in a substrate with a detection layer which is sensitive to radiation, the detector being characterized in that said detection layer is formed by a polycrystal film comprising either one of CdTe (cadmium telluride), ZnTe (zinc telluride) and CdZnTe (cadmium zinc telluride) or a laminate film of polycrystal including at least one thereof, and is doped with Cl.

Abstract: A method and apparatus for detecting gamma-rays is provided, wherein the gamma-ray detector apparatus includes a plurality of detector elements arranged in a stacked configuration. Each of the plurality of detector elements may include, a detector wafer having at least one anode separated from a cathode via a wafer material, wherein the wafer material includes a wafer material thickness d, and a wafer interface, wherein the wafer interface is electrically connected to the at least one anode.

Abstract: Rays incident upon a plurality of detection plates arranged along a normal direction are detected. A distance between the ray and the ray source is estimated based on the number of counted rays detected by each detection plate, and each interval distance of the detection plates. Moreover, the direction of the source of the ray is estimated based on each image obtained from each detection plate.

Abstract: Provided is an infrared radiation detector comprising an active layer having a front side and a back side. An anti-reflective coating is disposed on the front side and is configured to minimize reflection of incident light within a wavelength band of interest upon the front side. A highly-reflective coating is disposed on the backside and is configured to increase reflection within the wavelength band of interest upon the back side. Each one of the anti-reflective coating and highly-reflective coatings are comprised of a quarterwave stack of a plurality of layers each having an optical thickness equal to one-fourth of the wavelength band of interest. The wavelength band of interest is preferably in the range of from about 3.0 to about 5.0 microns.

Abstract: A device and method for measuring a depth of interaction of an ionizing event and improving resolution of a co-planar grid sensor (CPG) are provided. A time-of-occurrence is measured using a comparator to time the leading edge of the event pulse from the non-collecting or collecting grid. A difference signal between the grid signals obtained with a differential amplifier includes a pulse with a leading edge occurring at the time-of-detection, measured with another comparator. A timing difference between comparator outputs corresponds to the depth of interaction, calculated using a processor, which in turn weights the difference grid signal to improve spectral resolution of a CPG sensor. The device, which includes channels for grid inputs, may be integrated into an Application Specific Integrated Circuit. The combination of the device and sensor is included. An improved high-resolution CPG is provided, e.g., a gamma-ray Cadmium Zinc Telluride CPG sensor operating at room temperature.

Abstract: A high-energy radiation detector is disclosed which uses a semiconductor material to absorb high-energy radiation and emit secondary light in response. The semiconductor is designed to be largely transparent for the interband light it emits so that the generated secondary photons can reach the semiconductor surface, to be detected by a suitable photo-detector. The semiconductor thus plays a role of a scintillator with the emitted light registered by a photo-detector. Two different device embodiments are disclosed. The first embodiment employs a uniform bulk slab of the appropriately chosen semiconductor, such as n-doped InP. Its principal advantage lies in the simplicity and low cost. The second device employs a multi-layer heterostructure. The principal advantage of the second type detector is the possibility of a substantial enhancement in the efficiency of absorption of the primary high-energy radiation.

Abstract: A method is provided for fabricating contacts on semiconductor substrates by direct lithography that results in durable adhesion of the electrodes, increased interpixel resistance and the electrodes which act as a blocking contact, thereby providing for improved energy resolution in a resultant radiation detector.

Abstract: A semiconductor radiation detector is provided for improved performance of pixels at the outer region of the crystal tile. The detector includes a semiconductor single crystal substrate with two major planar opposing surfaces separated by a substrate thickness. A cathode electrode covers one of the major surfaces extending around the sides of the substrate a fraction of the substrate thickness and insulated on the side portions by an insulating encapsulant. An exemplary example is given using Cadmium Zinc Telluride semiconductor, gold electrodes, and Humiseal encapsulant, with the side portions of the cathode extending approximately 40-60 percent of the substrate thickness. The example with CZT allows use of monolithic CZT detectors in X-ray and Gamma-ray applications at high bias voltage. The shielding electrode design is demonstrated to significantly improve gamma radiation detection of outer pixels of the array, including energy resolution and photopeak counting efficiency.

Abstract: A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C.

Abstract: A monolithic solid-state detector using a staggered arrangement of pixels in multiple rows improves spatial resolution without requiring reduction in pixel size. Parallelogram shapes of CZT monolith allow tiling in one dimension without inefficient zones between monoliths. A scanning device using linear array of detectors with non-rectangular shape and staggered rows of detection elements such that no dead zones occur within a scan field.

Abstract: A high voltage switching power supply (10) for an X-ray/Gamma ray imaging camera provides high voltage switching and depolarization capabilities. The power supply includes a high voltage polarity switching and an image detector charge bleeding circuit (90) and is particularly useful with high energy radiation imaging cameras utilizing Cd—Te based detector substrates, especially substrates with blocked contacts, where charge accumulation in the detector material reduces imaging efficiency.

Abstract: A monolithic detector uses a grid to block x-rays from inter-pixel regions such as are believed to cause electrical noise in the pixel signals.