Abstract: In a preferred embodiment, a method of digitally de-randomizing pulses in a radiation spectroscopy system, the method including the steps of: receiving an input signal representative of a radiation detector output; analyzing the input signal to derive separate event samples and background samples; storing the event samples and the background samples; and reading stored event samples and background samples and adjusting spacing in time between adjacent event samples such that the event samples are spaced apart a time interval at least equal to pulse processing time of elements receiving an output of spaced apart event samples and the background samples.

Abstract: An infrared spectrometer is adapted to capture spectral data at high frequency and includes an aperture defining slit and tuning fork chopper for periodically admitting infrared radiation. A lens and a plurality of mirrors direct the infrared radiation through pair of calcium fluoride prisms that split the infrared radiation into spectral components. The spectral components are directed by an additional mirror and lens to an array of lead selenide pixels that generate a set of data indicative of the spectral component intensities. Data collection circuitry coupled to the pixel array and coupled to the tuning fork chopper collects the set of data at a selectable rate at least once during each opening of the aperture. A serial output on the data collection circuitry provides a list of data values representative of the spectral intensity at each pixel which can be then stored in a mass storage device as well as immediately analyzed based on selected criteria.

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: A system for processing signals from a radiation detector with semiconductors. A plurality of elementary detectors are placed side-by-side along a detection surface or a detection volume in which radiation referred to as incident radiation is capable of giving up its energy in at least one interaction. The device includes the supplying in response to each incident ray, an amount of energy corresponding to the sum of the energies given up during each interaction induced by the incident radiation. This device may be used in medical imaging.

Abstract: Multi-element microcalorimeter array. The microcalorimeter array includes at least two microcalorimeter with each microcalorimeter including a detector coupled thermally to a cold bath. Each detector has associated with it a thermal sensor to generate a signal proportional to a rise in the detector's temperature. A single negative voltage feedback JFET preamplifier circuit is connected to each of the detectors and includes a JFET with a gate, the signals from the thermal sensors connected to the gate. The output of the preamplifier circuit is proportional to radiation energy absorbed by the detector. Each detector has a different thermal recovery time so that the detectors can be discriminated. The multiplexing arrangement of the invention makes it possible to reduce the overall number of preamplifier and post-processing channels for a large multi-element array. This reduction in turn significantly lowers the JFET heat load, mass and power requirements for the microcalorimeter array.

Abstract: System and apparatus for locating sources of radiation emanating from predetermined radionuclides. The apparatus incorporates a large window display utilizing icon imagery to identify counting functions such as target count and background. A variety of radionuclide modes of operation can be selected by the operator and the system automatically defaults to detector bias selection and window reference voltage selection in correspondence with the elected radionuclide. A bar graph readout apprises the user of the amount of time or count level remaining in a target or background procedure and the flashing of icon identifiers occurs during such procedures. Pulse validation is improved by the utilization of a discriminator which evaluates pulse width.

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: 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: A gamma camera head including: a plurality of signal sources, each associated with a pixel position, the source producing a signal when a gamma ray absorption event occurs at or sufficiently close to its associated pixel, wherein the plurality of signal sources is associated with a contiguous extent of pixels; and a plurality of electronic circuits, each of which receives signals from at least two of the plurality of signal sources, wherein each circuit receives the signals only from sources associated with non-contiguous pixels.

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: 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: In order to improve detection efficiency and angular detection characteristics of an in-line X-ray film thickness monitor for monitoring the film thickness of a coated part during production of a product formed using the coated part, the film thickness monitor is provided with an X-ray tube of an end-window type for irradiating an X-ray beam onto the coated part, and an X-ray detector having an annular detecting plane arranged coaxially with the axis of irradiation of the X-ray beam. The X-ray detector detects fluorescent X-rays emitted by the coated part in response to irradiation thereof by the X-ray beam so that the thickness of the coating film can be determined based upon the intensity of the detected fluorescent X-rays.