Commissariat a L'energie Atomique

Commissariat a L'energie Atomique Et Aux Energies Alternatives

Francis Glasser

Bernard Thevenin

Jean-Pierre Rostaing

Loïck Verger

Patrice Ouvrier-Buffet

Jean-Luc Martin

Olivier Billoint

Patrick Audebert

Marc Cuzin

Olivier Peyret

Marc Accensi

Michel Garcin

A tool for detecting radiation includes a semiconductor detector material that interacts with ionizing radiation, an electrode that collects charge carriers generated in the detector material from an interaction with the ionizing radiation. A shaping circuit forms electrical pulses having a shape that depends on the amount of collected charge. A counting circuit counts the number of pulses and includes a counter and an incrementing element that increments the counter when a comparison parameter exceeds a threshold. The counting circuit further includes a duration-measuring element that measures a pulse duration (f) for each pulse and a peak-detecting element that determines a maximum amplitude (H) of each pulse. A combining element combines maximum amplitude and the pulse duration (f) to establish the comparison parameter. The comparison parameter is the product (H&#xd7;t) of a maximum amplitude of the pulse and the corresponding pulse duration.

Tool for detecting photon radiation, particularly adapted for high-flux radiation

Techniques for controlling a stability of response of a semi-conductor matrix imager composed of pixels, including a first phase of characterizing the stability of the pixels and a second phase of correcting the signals arising from the pixels during the measurements. The pixels are classed into stable pixels and unstable pixels according to a predetermined criterion, the unstable pixels being associated individually with a stable pixel whose characteristics serve as base for correcting signals arising from the unstable pixels.

Method for determining and correcting the stability of response of a semi-conductor matrix detector

The general field of the invention includes methods of calibrating X-ray detection systems, the systems including at least one X-ray generator and a detection array having a matrix of detecting semiconductor pixels and processing and calibration electronics. The calibration method includes, for all or some of the pixels: operating the X-ray generator at its nominal high voltage, the generator being placed opposite the detector; counting, using the processing and calibration electronics, the pulses emitted by each pixel through the effect of the radiation produced by the generator; establishing, for each pixel, an amplitude distribution for the counted pulses; applying, to each amplitude distribution, a statistical indicator so as to identify a particular amplitude, this particular amplitude then corresponding to the energy corresponding to said statistical indicator; and adjusting, using the processing and calibration electronics, calibration parameters for each pixel, taking account of the energy-amplitude relationship thus established.

Method of calibrating an X-ray detector

The particle detection circuit comprises a plurality of basic circuits. Each basic circuit comprises a particle detector element connected to an associated counter and a summing circuit having a first input connected to the output of the counter. Basic circuits, each forming a subpixel, are grouped together by series connection of their summing circuits to form a pixel. The output of the pixel, formed by the output of the summing circuit of a last basic circuit of the pixel, supplies counting signals representative of the number of particles detected by the set of basic circuits of the pixel. Disabling certain basic circuits of the pixel, by selective zero resetting of the first input of their summing circuit, can enable only the particles detected by certain zones of the pixel to be counted.

Particle detection circuit comprising basic circuits forming subpixels

A device for processing a signal (i) derived from a particular detector, the device including an integrator for measuring the total charge transported by an input signal (i) feeding the integrator for a predetermined time interval. The device further includes a plurality of units for receiving detector signal (i) derived from the particle detector, reducing the background noise present in the detector signal (i), and producing the input signal (i). The invention is applicable to various devices and appliances for measuring flow of particles such as photons.

Device for correcting a signal derived from a detector

A device for detecting energy radiation includes a semiconducting material capable of converting the radiation into electric charges, a measurement electrode, and a measurement circuit to measure the current delivered by the electrode. The device further includes polarisation electrodes constituted of conductive zones insulated electrically from each other, the polarisation electrodes and a measurement electrode sandwiching the material, and a voltage supply adapted to bring each of these conductive zones to an adjustable voltage.

High dynamic radiation detection device

Digital radiography device protected against risk of electrocution

A method and a device for taking digital images in which the exposure time of the object to X or .gamma. rays is controlled and optimized in a way that produces, with each taking of an image, a non-saturated image and minimizes the dose of radiation necessary to produce this image. The device includes at least one image sensor having measurement pixels and pixels. The measurement pixels measure a current representative of a dose of radiation received by the object, and the image pixels are used to form the digital image. The dose of radiation measured by the measurement pixels is compared to a guide-line value, and when this dose measurement reaches the guide-line value the collection of the electrical charge by the image pixels is stopped. The stopping of the collection of the electrical charges is performed without stopping the radiation emission.

Method and device for the taking of digital images with control and

The present invention relates to a multisection imaging device incorporating a source (10) of ionizing radiation (11) and an array of semiconductor detectors (12) able to receive said radiation (11) having traversed a means (14), in which the semiconductor detectors are bidimensional detectors associated with one another in order to obtain several detection rings able to rotate about said means (14), so as to permit the simultaneous acquisition of several imaging sections.

Multisection imaging device

The invention concerns an X-ray tomograph device. This device makes it possible to obtain the image (1) of a plane cutting (2) of an object (3). In particular, it comprises an X-ray source (4) which supplies high energy pulses which traverse the object. At least one measurement detector small bar (10) receives the attenuated energy pulses which have traversed the object. A display and processing means connected to the detectors supplies the image of the cutting. These processing means include amplifier-integrator circuits (13) connected to the detectors (10) and to a computer (15) controlling the integration period of the detection pulses suplied by the detectors (10). The computer corrects the value of the amplitude of each detection pulse by talking account of an intermediate integration value so as to take account of the drag of each pulse and the stray current of each detector.

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Eybens, France

Francis Glasser