Abstract: A semiconductor detector including at least one block of detector pixels, each detector pixel being composed of a semiconductor element with a first face covered by a first armature and a second face covered by a second armature. The detector pixels are assembled side by side such that the first armatures define a detector plane. The first armatures are covered by a plane conducting structure that connects them together electrically. The detector does not have any dead area in which detection is impossible. The semiconductor is particularly applicable to detection of ionizing radiation (gamma rays, X-rays, etc.

Abstract: A semiconductor base device for the detection of gamma radiation. The semiconductor base device includes a semiconductor base detector with a resistivity exceeding 109 &OHgr;·cm. An operational amplifier is located directly at the detector output, without a decoupling capacitor between the detector and the preamplifier. A data processing device makes use of the rise time of the electronic component of a signal output by the detector.

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: The invention relates to a method and device for using a signal, or a set of data representative of the time variation of a signal output by a semiconductor detector (52), in response to the interaction of a .gamma. photon with the semiconductor material in which a signal or data is produced, being representative of the rise time of the electronic component of the signal output by the detector. The total detected charge may also be measured. Charge-rise time correlation curves are created.

Abstract: The invention concerns an X-ray tomographic detector.This detector comprises a sealed chamber (4) containing a gas able to be ionized by X-rays having traversed a device or an object. This chamber comprises on a front face an X-ray inlet gate (5) and contains an X-ray detection unit (11). Connections means (27, 28, 29, 32, 33) traversing a rear face of the chamber (9) to link the detection means to measuring (14) and feed (15, 16) means outside the chamber. The detection means comprise electrodes (19) and a polarization plate (18) separated by an insulating brace (3) transparent to X-rays. According to the invention, this brace has the shape of frame. This frame rests firstly on the polarization plate (18) and secondly on conductive strips (22, 24) brought to the same potential reference (16) as that of the electrodes.Application for X-ray tomography.

Abstract: To take account of the decrease time constant of the intensity of the light scintillation and the statistical fluctuation of the scintillation, which is a resolution deterioration factor, it is appropriate to integrate the electric pulse resulting from the detection of an event by photomultiplier tubes. If, during this integration, a stacking phenomenon occurs, a second pulse is superimposed on the first and falsifies the calculation of the scintillation coordinates. This stacking is eliminated by validating the calculation of these coordinates by checking the value reached by the scintillation energy at the end of said integration. The value of this energy is measured by integrating the signal representing the intensity of the light scintillation.

Abstract: In the synchronous detection signals of frequency Fo immersed in a noise, an auxiliary signal is produced having a period 1/2 Fo and in the form of a rectified symmetrical wave, by rectifying a symmetrical wave of period 1/Fo. The signal to be filtered is multiplied by the auxiliary signal and synchronous filtering or synchronous detection on the frequency Fo is performed on the signal obtained after the above-mentioned multiplication. Preferably the auxiliary signal is produced in the form of a rectified sinusoidal wave and a square wave reference signal from which the above-mentioned symmetrical wave is derived, having the period 1/Fo, is also used to control the synchronous detection or the synchronous filtering.