Abstract: The back surface of a thinned charged-coupled device (CCD) is treated to eliminate the backside potential well that appears in a conventional thinned CCD during backside illumination. The backside of the CCD includes a delta layer of high-concentration dopant confined to less than one monolayer of the crystal semiconductor. The thinned, delta-doped CCD is used to determine the energy of a very low-energy particle that penetrates less than 1.0 nm into the CCD, such as a proton having energy less than 10 keV.

Abstract: Devices and techniques for using a prism to couple IR radiation to a quantum-well sensor with a polarization substantially perpendicular to the quantum-well layers.

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: Zones of a passive infrared (PIR) motion detector lens are staggered at close range to provide for pet immunity. In a dual sensor, dual lens configuration, the sensor signal is acted on to generate an alarm only when the sensor signal is simultaneous, indicating that an infrared emitting object big enough to cross both staggered zones of a zone pair has been detected. To further enhance sensitivity and immunity to noise, two dual element PIR sensors are arranged in opposite polarity with their elements vertically parallel. The sensor output is simultaneous and of opposite polarity, and noise can be suppressed by blocking like-polarity signals.

Abstract: This is a method of generating a plurality of images of a substrate from radioactive radiation coming from a plurality of radioactive tracers contained in the substrate. To this end, data representing the different detection signals generated by a detector are memorised, individually for each radioactive emission detected during a certain observation period, then statistical processing of these data is carried out in such a way as to estimate the images of the different tracers which correspond best to the set of memorised data.

Abstract: According to the present invention, sub-windows using a TEW technique are centered to energies corresponding to 1/n and 1/m of maximal photon number in a standard energy spectrum without any scattering component. It is thus possible to improve a count coefficiency, while broadening a main window to a maximal possible extent, without underestimating the scattering component and crosstalk component.

Abstract: A method for generating a high resolution image in a radiation imaging system which produces multiple exposure signals from a movable detector array is disclosed. The image data signals or image acquisition signals generated from the image detector assembly of the image radiation system during an imaging cycle are passed through a finite impulse response filter having a combined frequency response comprised of an inverse filter frequency response portion and a noise regularization frequency response portion such that the noise regularization decrease the frequency response of the filter as the frequency of the data signals increase thereby effectively preventing blurring of the image produced from the image data signals.

Abstract: Erasure of an x-ray imaging device is performed by applying high voltage and erasing light simultaneously. The polarity of the high voltage may be reversed during the erasure operation. This produces an erasure that eliminates non-uniformities or ghosts arising from a previous image.

Abstract: In a method for correcting the image errors arising during an x-ray diagnostic measurement from the memory effect of a radiation-sensitive structure, particularly in the form of a photodiode array, of a solid-state detector which receiving the x-rays, given a change in the operating mode with a change of the radiation dose, a correction image is determined that is subtracted from the detector image obtained from the solid-state detector.

Abstract: A charged coupled device is disclosed including an asymmetrical split with independent control over the regions on opposite sides of the split. The charge coupled device is configurable for use in multiline or kinetic spectroscopy, and includes two separate horizontal registers with optional charge dump regions for improving efficiency.

Abstract: A semiconductive detector includes a semiconductor substrate having electrodes formed at two opposite-facing surfaces thereof. A peripheral side-wall extends between the two opposite facing-surfaces, and an electrical insulator is formed on at least a portion of the side wall. An electrical conductor is provided over the insulator. A bias voltage may be applied to the conductor such that the electrical insulator and the conductor operate generally in a manner of a field effect transistor.

Abstract: A germanium detector measures an energy spectrum of a gamma ray flux. The detector includes a cooling layer continuous over a periphery of the columnar germanium crystal. The cooling layer reduces current leakage induced by heat, so that high energy gamma rays can be precisely detected. A combination of a plurality of germanium crystal bodies connected one another to form the germanium crystal of at least 20 cm leads to a more precise detection of high energy gamma rays. A method for determining a photonuclear reaction cross section using the germanium detector enables measurement of the energy dependence of a photonuclear reaction cross section at high resolution. The method employs a white gamma ray flux radiated to a nuclide. The germanium detector measures the spectrum of a transmission gamma ray flux transmitted through the nuclide. Peaks are specified in the obtained spectrum. An atomic nucleus can be transformed using a monochromatic gamma ray flux having an energy level corresponding to the peak.

Abstract: A photodetector using a III-V nitride and having predetermined electrical properties is disclosed. The photodetector includes a substrate with interdigitated electrodes formed on its surface. The substrate has a sapphire base layer, a buffer layer formed from a III-V nitride and a single crystal III-V nitride film. The three layers are formed by electron cyclotron resonance microwave plasma-assisted molecular beam epitaxy (ECR-assisted MBE). Use of the ECR-assisted MBE process allows control and predetermination of the electrical properties of the photodetector.

Abstract: A gamma-rays measurement method of radionucludes (iodine-131, cobalt-60, etc.) coexisting with radionuclides (nitrogen-13, fluorine-18, cobalt-58, etc.) each emitting a pair of annihilation gamma-rays, particularly in primary water of a nuclear reactor by the use of a gamma-ray spectrometric system which includes a primary detector for detecting the gamma-rays and the one annihilation gamma-rays as pulses, a secondary detector for detecting the other annihilation gamma-rays as pulses, and shield detector for detecting gamma-rays Compton-scattered and escaped from the primary to shield detectors as pulses. The method comprises counting the pulses of the secondary detector in anticoincidence with the pulses of the primary detector, thereby to reject the recording of the annihilation gamma-rays from the primary detector, thus minimizing the annihilation gamma-rays disturbing to the measurement, followed by determining count numbers of the gamma-rays.

Abstract: Method and apparatus for generating a large-field, high-resolution digital image of an object by sequentially generating multiple optical scenes representative of different portions of the object, and then sequentially directing each optical scene onto an optical detector to generate multiple sub-images of the different portions of the object. Each scene is induced using a separate X-ray sub-beam, each of which is generated by spatially filtering a portion of an incident X-ray field with a spatial filter moving in concert with the scene-directing device. Once generated, the sub-images are combined to form the large-field, high-resolution image.

Abstract: The invention relates to forming an image from a random particle flux. Particles of the flux are detected by a discrete-cell detector having a cell size finer than conventionally used. Preferably, the cell size is sufficiently small that almost all cells of the detector count at most one particle during the image acquisition time. The count data are filtered through a band-limiting filter whose bandwidth lies between a bandwidth corresponding to the detector cell size and the flux bandwidth of interest. Outliers may be flattened before filtering. Neighborhoods around each cell are evaluated to differentiate stationary regions (where neighboring data are relatively similar) from edge regions (where neighboring data are relatively dissimilar). In stationary regions, a revised estimate for a cell is computed as an average over a relatively large neighborhood around the cell. In edge regions, a revised estimate is computed as an average over a relatively small neighborhood.

Abstract: A method for fabricating an integrated infrared sensitive bolometer having a polycrystalline element whereby an oxide region deposited on silicon nitride covered with a first polysilicon layer which is etched to provide a location for a bolometer element. A second polysilicon layer is deposited and doped to achieve a desired temperature coefficient of resistivity of 1 to 2%/.degree.C. The second polysilicon layer forms an IR sensitive element over the oxide region. Openings are etched in the IR sensitive element to permit an etchant to remove the oxide region resulting in the sensitive element being suspended over a cavity.

Abstract: A detecting or monitoring device for laser radiation is able to oeprate at room temperature and employs a thin film of semi-conductor material of non-centrosymmetric lattice structure having a substantial crystallographic texture; thin film may suitably be tellurium in a film thickness of 1 to 100 .mu.m, supported on a substrate of single crystal silicon.

Abstract: Methods of and apparatus for in vivo radiation measurements relay on a MOSFET dosimeter of high radiation sensitivity with operates in both the passive mode to provide an integrated dose detector and active mode to provide an irradiation rate detector. A compensating circuit with a matched unirradiated MOSFET is provided to operate at a current designed to eliminate temperature dependence of the device. Preferably, the MOSFET is rigidly mounted in the end of a miniature catheter and the catheter is implanted in the patient proximate the radiation source.

Abstract: A method to significantly increase the quantum efficiency (QE) of a CCD (or similar photosensor) applied in the UV, far UV and low energy x-ray regions of the spectrum. The increase in QE is accomplished by overthinning the backside of a CCD substrate beyond the epitaxial interface and UV flooding the sensor prior to use. The UV light photoemits electrons to the thinned surface and charges the backside negatively. This in turn forms an accumulation layer of holes near the Si-SiO.sub.2 interface creating an electric field gradient in the silicon which directs the photogenerated signal to the frontside where they are collected in pixel locations and later transferred. An oxide film, in which the backside charge resides, must have quality equivalent to a well aged native oxide which typically takes several years to form under ambient conditions. To reduce the amount of time in growing an oxide of sufficient quality, a process has been developed to grow an oxide by using deionized steam at 95.degree. C.

Abstract: Disclosed is a dosimeter-radiation meter for measuring a dose flow of ionizing radiation including a Geiger-Mueller tube and data processing circuitry. The data processing circuitry comprises a circuit for shaping and amplifying the pulses delivered by the tube, circuits for storing digital representations of characteristic parameters associated with a particular Geiger-Mueller tube, a section circuit for applying either sensed pulses or the coded parameters to a calculation unit, a calculation unit for counting pulses and for correcting the pulse count according to the precoded stored parameters and a display unit for displaying the dose count or flow rate.

Abstract: An intrusion detection system includes a plurality of infrared radiation sensitive elements, each of which comprises first and second spaced electrodes between which polarized pyroelectric material is positioned, each element being operative to produce a voltage proportional to the rate of change of infrared radiation incident thereon. The elements are closely spaced to one another and cover substantially all of at least one surface of the pyroelectric material. Multiple fields of view of areas under surveillance are fully covered (with negligibly small gaps). Alternate sensor elements are connected to a first amplifier channel and the other sensor elements are connected to a second amplifier channel. Coincidence means produces an alarm output in response to concurrent intruder signal generation by both of the amplifier channels.

Abstract: An ionizing radiation intensity dosimeter apparatus and method based on carrier recombination saturation times for irradiated PN junction semiconductor devices following termination of a radiation pulse. Normally-on quiescent condition, moderate radiation doses at relatively high dose rates, and a read-out arrangement employing gated burst counting are included.

Abstract: An alarm device responsive to entering or trespassing comprising:(a) a sensor circuit, including an infrared ray sensor, producing an output having positive and negative peaks based on outputs of said sensor being produced when a target to be sensed passes within the region of vision monitored by said sensor,(b) a level detecting circuit comprising a first detector producing an output when the positive peak of the output fed from said sensor circuit exceeds a predetermined level, and a second detector producing an output when the negative peak of the output fed from said sensor circuit exceeds a predetermined level,(c) a timer circuit comprising a first timer producing an output which continues for a predetermined time interval or above from a time at which the output of said first detector is produced, and a second timer producing an output which continues for a predetermined time or above from a time at which the output of said second detector is produced,(d) an AND circuit comprising a first circuit produc

Abstract: A self-calibrated neutron radiation monitor includes a flux responsive element comprised of intrinsic silicon neutron detectors and self-calibration resistors in a single structure. As the resistance of the flux responsive element increases to the value of successive calibration resistors, known increments of flux have been encountered.

Abstract: A system for obtaining improved resolution in relatively thick semiconductor radiation detectors, such as HgI.sub.2, which exhibit significant hole trapping. Two amplifiers are used: the first measures the charge collected and the second the contribution of the electrons to the charge collected. The outputs of the two amplifiers are utilized to unfold the total charge generated within the detector in response to a radiation event.

Abstract: A layer of X-ray photoconductor is sandwiched between electrodes for conversion of X-radiation to an electrical signal. The photoconductor layer is biased, and films of zinc sulfide may be used between the layer and each electrode, to minimize dark current. Arrays of solid state radiation detectors utilizing the biased photoconductive conversion layer are also disclosed.

Abstract: A method for detecting and measuring electromagnetic or particle radiation by electrical means has been provided. A piece of semiconductor material, such as phosphorus-doped silicon, fitted with at least two electrodes is used as the detector and the measurement is performed by exposing the detector to the radiation to be measured and by applying an electric field between the electrodes, which will cause an electric breakdown after a certain delay time. The length of this delay time preceding the breakdown is altered by radiation and the magnitude of the change is serving as a measure of the intensity of the radiation falling on the detector.

Abstract: A coaxial gamma ray detector is fabricated using intrinsic semiconductor material in a geometry whereby full depletion of electrical carriers is prevented within a small region proximate the point of electrical contact thereby allowing greater biasing potentials across the detector and, consequently, providing reduced electronic noise and increased energy resolution.

Abstract: The invention is founded on the discovery that type IIb diamond which has been rendered electrically non-conductive by being subjected to radiation capable of inducing atomic displacements becomes electrically conductive again when subjected to ionizing radiation. The invention thus provides a method of causing an electrical current to flow through a body of type IIb diamond which has been subjected to radiation capable of inducing atomic displacements by applying an electrical potential across the body and exposing the body to ionizing radiation while maintaining an electrical potential across the body. The invention also provides a novel diamond consisting of a type IIb diamond having only a portion which has been subjected to radiation capable of inducing atomic displacements.

Abstract: A plurality of infra-red detectors having storage capabilities are arranged in an array having X and Y address lines and a signal readout line. The detector elements have a semiconductor substrate of extrinsic material such as suitably doped silicon, and operate to store and provide readout of signal information using majority carriers, there being no requirement for depletion regions or P-N junctions. Majority carrier diffused regions are formed along the front surface of the substrate, the X and Y address lines and the signal line being placed adjacent to these diffused layers as well as terminals for applying a bias voltage and for forming a storage capacitor for each of these detector elements. Bias is applied in a polarity such as to attract majority carriers generated by the infra-red radiation to the surface for storage in the storage capacitor, the stored carriers providing a readout signal on the signal line when an addressing signal appears on the X and Y lines.

Abstract: A radiation detector that combines the characteristics of high quantum efficiency in the UV spectrum with good IR transmission characteristics so that it may be used in association with an IR sensor to produce a coaxial transducer suitable for use in association with unfiltered, high-resolution optics. The detector is a solid state photovoltaic Schottky barrier semi-conductor junction comprising a thin platinum layer laid over single-crystal cadmium sulfide. Processing, including lapping, polishing, and chemical etch, produces a surface suitable for providing radiation sensitivity which drops off sharply outside of the ultraviolet spectrum beyond 550 nanometers. The platinum layer is approximately 35 angstroms in thickness and is therefore transparent both to ultraviolet and infrared radiation. The infrared radiation passes through the cadmium sulfide wafer and through a window in the indium ohmic contact surface on the second surface of the cadmium sulfide crystal.