Abstract: A detection head and collimator for a gamma camera. The detection head includes several elementary detectors with semiconductors adjacent to each other to form a detection plane. The collimator is placed in front of the detection plane and includes a number of ducts laid out in a repetition pattern. The shape of the elementary detectors and the repetition pattern are rectangular in the detection plane.

Abstract: This relates to a helicopter in which the outlet nozzle from the turbine engine is provided with an exhaust pipe which mixes the combustion gases with fresh air and directs the mixture downward. Viewed from the outside of the helicopter, the exhaust pipe is completely concealed by a cowling which is separated from said exhaust pipe by an empty intermediate space, air intakes being provided to create a flow of ambient air, including during hovering flight, along the intermediate space as far as an outlet which is open substantially vertically downward.

Abstract: A detection array for ionizing radiation tomography for obtaining the image of at least one section of an object or organ. The array has at least one chamber (1) provided with a radiation-transparent entrance window (2) and in the chamber a detection stack (E1) incorporating a conductive polarizing plate (3) parallel to the sectional plane and a series of identical electrodes (5) parallel to the sectional plane. An insulating spacer (9) is placed between the electrodes (2) and the plate (5) and has, facing the window, at least one radiation-opaque intermediate plate (14) parallel to the sectional plane. This intermediate plate (14), the electrodes (5) and the polarizing plate (3) are disturbing elements which, separated by a distance d, make it possible to eliminate the artefacts for linear or quasi-linear inclusions in the object.

Abstract: A process for the examination of the flat radiograph of an object irradiated with the aid of an ionizing radiation source is disclosed. In an ionization chamber is detected the latent image of the object formed by the different electrical charges produced in the volume of the chamber under the influence of the impact of the radiation flux which has traversed the object. As this irradiation is continuous, the object to be examined is moved relative to the ionization chamber in the direction and at the migration speed of the ions formed in the electrical field thereof.

Abstract: Material for scintillators, application to the construction of very fast, high energy photon detectors and to the construction of tomographs.The material for scintillators is constituted by barium fluoride which, under excitation, is subject to light emission having a slow component with a maximum centered on 3200 .ANG. and a fast component with a maximum centered on 2250 .ANG., the barium fluoride being purified so as to reduce the defects of its crystal lattice, in order to reinforce the intensity of the fast component of its light emission.

Abstract: The invention relates to a process for making a multidetector of X-rays forming a plane beam. This multidetector comprises a tight chamber filled with an ionizable gas and, in this chamber, at least one main multidetector assembly comprising a plane conducting plate, electrically insulated from the chamber and a plurality of flat electrodes parallel to the plate, insulated from this plate. This process is characterized in that it consists in making the electrodes, as well as main connections between these electrodes and measuring points outside the chamber enabling the currents circulating respectively in these electrodes to be sampled, on a main face of an electrically insulating plate, these main connections being electrically insulated from the chamber and passing therethrough in tight manner, opposite the source which emits the X-rays. The invention is more particularly applicable to X-ray multidetectors intended for the tomography or radiography of organs or for checking baggage.

Abstract: The present invention relates to an X-ray detector adapted to detect rays having passed through an object or an organ. This detector comprises at least one main tight chamber containing a gas ionizable by X-ray and, in this chamber, a plate for collecting the charges resulting from ionization of the gas. It comprises a secondary ionization chamber, coupled to the main chamber to compensate the scattering current.

Abstract: The present invention relates to a detector of X-rays having passed through an object or an organ. This detector comprises at least one tight ionization chamber containing a gas ionizable by the rays issuing from the object and, in this chamber, a plate for collecting the charges and a series of electrodes for collecting the charges resulting from the ionization of the gas. The ionization chamber further contains a gas capable of creating, within the mixture thus formed, a movement of gas opposite the movement of the ions.

Abstract: The present invention relates to a portable computing device comprising, in known manner, means for adding digital information, means for determining periods of time and display means, wherein it also comprises a nuclear detector adapted to deliver electrical signals whose amplitude spectrum depends biunivocally on the energy spectrum of the radiation in which it is placed and means for converting these signals into digital information, the addition means receiving said digital information, the means for determining periods of time controlling said addition means so as to make a calculation of the dose of nuclear radiation received during a period of time, called integral dose, which is displayed by said display means. The invention is more particularly applicable in the domain of protection against radiation, or health physics.

Abstract: The present invention relates to a portable radiation measuring device, comprising a detector adapted to deliver electrical signals whose amplitude spectrum depends biunivocally on the energy spectrum of a radiation which may be received by the detector, amplification means and electronic means for compensating the sensitivity of the detector as a function of the energy so as to render it identical to that of human tissues, producing an output signal which is in a constant ratio with the energy of said radiation which may be absorbed by human tissues and display means, connected to the amplification and compensation means, for displaying the dose of radiation received by the detector.

Abstract: Radiation detector comprising an ionization chamber having at least two juxtaposed electrodes, formed by plates respectively raised to a first potential and to a second potential, said plates being supported at at least one of their upper and lower ends by upper and lower insulating strips, wherein the plates form in the vicinity of the insulating strips baffles which protect the strips against radiation.

Abstract: In a device comprising one or a number of X-ray beams of suitable shape and at least one cell for detecting X-rays which have passed through the organ to be analyzed, the detection cells are ionization chambers comprising two parallel electrodes separated by a radiation-detecting medium for converting the X-rays to electron-ion pairs. The electrodes are connected to two terminals of a voltage source and the detection cells are associated with means for measuring the charge collected during a predetermined period of time under the influence of the X-rays.

Abstract: A device for localizing neutrons is made up of modular elements placed within an enclosure which is transparent to neutrons and filled with a gas, each modular element being constituted by a series of parallel wire anodes, means for producing an electric field around each anode wire so as to give rise to charge multiplication when an electron penetrates into the field, a cathode placed in the proximity of the array of wire anodes, means for attaching the anode wires to the cathode walls and means for providing electrical insulation between the cathode and each anode wire.

Abstract: A proportional detector for the localization of particles comprises a leak-tight chamber filled with fluid and fitted with an electrode of a fisrt type consisting of one or more conducting wires and with an electrode of a second type consisting of one or more conducting plates having the shape of a portion of cylindrical surface and a contour which provides a one-to-one correspondence between the position of a point of the wires and the solid angle which subtends the plate at that point, means being provided for collecting the electrical signal which appears on the plates.