Abstract: In a method and an apparatus for recording radiation image information of a subject on an electrostatic recording material, photoelectromotive force noise is reduced and stabilized. The apparatus comprises a switch 52 for switching voltage supply from a power supply 53 to a detector 10, a high voltage generator 62 for supplying a high voltage HV to a radiation source 61, and control means 70 for controlling light source control means 40. The control means 70 causes a control signal C2 input to the switch 52 to become LOW so that an electrode of a first electrode layer 11 and a stripe electrode 16 have the same potential. In this state, the control means causes a control signal C1 input to the light source control means 40 to become LOW and causes a planer light source 30 to emit EL light as pre-exposure light. Pre-reading in which this pre-exposure light is irradiated on a reading photoconductive layer 14 is carried out in this manner.

Abstract: An improved semiconductor radiation detector which involves engineering the internal electrical field through an external infrared light source. A planar semiconductor radiation detector is applied with a bias voltage, and an optical light beam with a selected photon energy is used to illuminate the detector and engineer the internal electric field. Different light beam intensities or photon energies produce different distributions of the internal electric field. The width of the electric field can be fine-tuned by changing the optical beam intensity and wavelength, so that the radiation detector performance can be optimized. The detector is portable, small in size, and operates at room temperature.

Abstract: A noise reduced photon detector incorporates an array (10) of semiconductor diode detector elements (12). Each element (12) has an extrinsic active layer (20) sandwiched between two layers (18, 22) of wider bandgap and mutually opposite conductivity type. These layers are in turn sandwiched between two further layers (16, 24) of wider bandgap than the active layer (20) and of higher doping than the other layers (18, 22). A mirror (34) extends round much the array (10) and isolates each element (12) from photons emitted by other elements (12). In operation the elements (12) are reverse biased and exhibit negative luminescence which reduces their photon emission. These two effects reduce unwanted photon generation and absorption, and consequently photon noise is also reduced.

Abstract: Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts.

Abstract: Device for discrimination of electrical pulses output from at least one semiconductor radiation detector, comprising: at least one means (106a, 106b) of transforming pulses capable of increasing a value of a derivative of the pulse with respect to at least one parameter called the slope parameter, at least one integrator (108a, 108b) capable of establishing a “characterization” value for each transformed pulse, the said value being obtained by integration of the transformed pulse, pulse sort means (110) as a function of their characterization value.

Abstract: An electron gas grid semiconductor radiation detector (EGGSRAD) useful for gamma-ray and x-ray spectrometers and imaging systems is described. The radiation detector employs doping of the semiconductor and variation of the semiconductor detector material to form a two-dimensional electron gas, and to allow transistor action within the detector. This radiation detector provides superior energy resolution and radiation detection sensitivity over the conventional semiconductor radiation detector and the “electron-only” semiconductor radiation detectors which utilize a grid electrode near the anode. In a first embodiment, the EGGSRAD incorporates delta-doped layers adjacent the anode which produce an internal free electron grid well to which an external grid electrode can be attached. In a second embodiment, a quantum well is formed between two of the delta-doped layers, and the quantum well forms the internal free electron gas grid to which an external grid electrode can be attached.

Abstract: An active matrix substrate provided with a matrix of electrode wires, a plurality of thin film transistors (TFTs) individually formed at intersections of the matrix, and pixel electrodes connected to the electrode wires through the thin film transistors (TFTs) is laminated to a counter substrate provided with connecting electrodes by means of an anisotropic conductive bonding agent. The counter substrate is composed of 12 divided pieces which are tiled as panes.

Abstract: A device for determining the photon energy E1 and direction cone angle of incident gamma ray includes a radiation detector for receiving an incident gamma ray having an unknown photon energy E1 and an unknown direction and for scattering the gamma ray with two Compton scattering interactions and a subsequent scattering or absorption interaction. The detector provides three outputs, each output corresponding to one of the Compton scattering and the subsequent scattering or absorption interactions, to a processor, which is programmed to calculate the photon energy E1 and direction cone angle of the incident gamma ray based on these outputs.

Abstract: A two-dimensional image detector comprises an active matrix substrate provided with a pixel layer which includes pixel electrodes arranged in matrix form and switching elements; a counter substrate, provided with an upper electrode provided over substantially the entirety of the pixel layer, and a semiconductor layer having photoconductivity, provided opposite the pixel layer; and a conductive adhesive material which connects the active matrix substrate and the counter substrate to each other; in which the active matrix substrate is provided with a second electrode section for inputting a signal to the upper electrode of the counter substrate, and the upper electrode and the second electrode section are electrically connected to each other via a conductive member.

Abstract: A radiation detector for detecting ionizing radiation. The detector includes a semiconductor having at least two sides. A bias electrode is formed on one side of the semiconductor. A signal electrode is formed on a side of the semiconductor and is used to detect the energy level of the ionizing radiation. A third electrode (the control electrode) is also formed on the semiconductor. The control electrode shares charges induced by the ionizing radiation with the signal electrode, shielding the signal electrode until the charge clouds are close to the signal electrode. The control electrode also alters the electric field within the semiconductor, such that the field guides the charge clouds toward the signal electrode when the clouds closely approach the signal electrode. As a result, signal loss due to trapped charge carriers (i.e., electrons or holes) is minimized, and low-energy tailing is virtually eliminated.

Abstract: The invention provides a method for detecting gamma or X-ray radiation with a room temperature solid state detector, which comprises the selection of the detector's electron trapping parameter (&mgr;&tgr;)e and/or the detector voltage V so as to tune the electron trapping to optimally compensate for the incomplete charge collection.

Abstract: A semiconductor P-I-N detector including an intrinsic wafer, a P-doped layer, an N-doped layer, and a boundary layer for reducing the diffusion of dopants into the intrinsic wafer. The boundary layer is positioned between one of the doped regions and the intrinsic wafer. The intrinsic wafer can be composed of CdZnTe or CdTe, the P-doped layer can be composed of ZnTe doped with copper, and the N-doped layer can be composed of CdS doped with indium. The boundary layers is formed of an undoped semiconductor material. The boundary layer can be deposited onto the underlying intrinsic wafer. The doped regions are then typically formed by a deposition process or by doping a section of the deposited boundary layer.

Abstract: Detectors are used to monitor the status of spent nuclear fuel storage containers non-invasively while they remain in storage casks. The detectors measure neutron flux and &ggr;-ray flux and may also measure temperature variations of the spent nuclear fuel. The measurements can be accomplished actively or passively, with minimal exposure of individuals to radiation fields or other hazardous conditions. Preferred neutron and &ggr;-ray detectors have a semiconductor active region that is resistant to neutron damage. Incipient structural failures may also be detected using measurements based on electrical continuity, with data being transmitted to an external pickup coil.

Abstract: In a two-dimensional image detecting device, an active-matrix substrate which is provided with an electrical charge storage capacity and TFT(thin-film transistor) and an opposing substrate which is provided with a semiconductive substrate are bonded to each other by using connecting members with conductivity and bonding property that are patterned in accordance with pixel electrodes of the electrical charge storage capacity. With this arrangement, it is not necessary to form a semiconductive layer onto the active-matrix substrate, the TFT having been already formed on the active-matrix substrate; thus, it is possible to form the semiconductive substrate of the opposing substrate that is made of a material selected from the group consisting of CdTe and CdZnTe, etc. Consequently, the two-dimensional image detecting device is superior in response and is capable of dealing with moving image as well.

Abstract: A method and apparatus for multicolor detection employing the natural chromatic aberration of a diffractive microlens to detect two or more colors or light. In the preferred embodiment the diffractive microlens detects two colors in the VLWIR spectral region and is focused on a two-part detector having a central region to detect the shorter bandwidth and a concentrically disposed region to detect the long band, VLWIR radiation. These detectors are arranged in a multicolor focal plane array to allow imaging.

Abstract: A method, suitable for forming metal contacts on a semiconductor substrate at positions for defining radiation detector cells, includes the steps of forming one or more layers of material on a surface of the substrate with openings to the substrate surface at the contact positions; forming a layer of metal over the layer(s) of material and the openings; and removing metal overlying the layer(s) of material to separate individual contacts. Optionally, a passivation layer to be left between individual contacts on the substrate surface may be applied. Etchants used for removing unwanted gold (or other contact matter) are preferably prevented from coming into contact with the surface of the substrate, thereby avoiding degradation of the resistive properties of the substrate.

Abstract: The invention relates to a device for measuring the rise time of the electronic component of a signal disturbed by electronic noise and whose signal-to-noise ratio is mediocre. It incorporates a differentiating circuit (C12, C11) having at least one resistor (r) and one capacitor (c) implementing a high pass filter for filtering the low frequency background noise of the signal from the detector and a discriminating circuit (C21, C22) incorporating a comparator (k) for performing a comparison with the filtered signal from the differentiating circuit and an offset voltage selected as a function of the noise level interfering with the signal from the detector.

Abstract: A surgical system wherein a two component hand-held probe is provided. The probe includes a sterilizable and reusable detector portion formed principally of metal in combination with a disposable handle and cable combination. Formed principally of metal components, the detector assembly includes a crystal receiver within which a detector crystal is retained in compression by an annular metal ring assembly having thin inwardly depending tines which contact the crystal forward surface and additionally apply the electrical ground thereto. An access channel rigidly supports bias and signal carrying electrical leads through a crystal mount to a rearward face thereof. The rearward face rigidly supports the forward stage of a preamplifier. In one embodiment a rigid polymeric crystal mount is employed. Particularly for this embodiment, a cup-shaped, shield containing window assembly is utilized.

Abstract: A hand-held radiation probe is configured having a crystal thickness as well as a bias generated electrical field which have values to cause the semiconductor crystal to operate in a trapping-dependent operational mode wherein a trapping of substantially all carriers generated by radiation impinging upon the crystal forward face are trapped. The bias level voltage is selected to achieve adequate photopeak heights and to permit the windowing out of lower energy Compton scattering and other noise phenomena.

Abstract: A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm3 detector is capable of measuring 137Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24° C.) energy resolutions of 2.68% FWHM for 137Cs 662 keV gamma rays and 2.45% FWHM for 60Co 1.332 MeV gamma rays.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector including a plurality of closely-packed detection modules. Each detection module includes a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements.

Abstract: A method for obtaining both spatial and energy resolution in compound semiconductor x-ray detectors using charge carriers of only a single polarity. A negatively biased cathode contact is applied to one side of a block detector material and an array of anode stripes is applied to the other side. Absorbed x-rays generate charge clouds in the detector block, and charge sensitive preamplifiers measure the time varying charges qi(t) induced on the anodes by the motion of these charge clouds within the detector. For each stripe j, one or more secondary signals Qk,m(t) are formed as weighted sums of the signals qk(t) from the stripe j and a combination of its near neighbors. One or another of these signals Qk,m(t) can then be processed to obtain the energy of the absorbed x-ray, the position where it was absorbed, both laterally and in depth, and the time of the absorption.