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[en] A new method of hollow articles radiography is presented enabling to eliminate shortcomings coupled with medical personnel irradiation when the ampoule incorporating radioactive substance is removed from the protective container and adjusted in the article. The method presented permits to transport the ampoule from the protective container immediately into the inner cavity of the article
[en] A method of measuring neutron density is presented. It consists of autoradiography, by β rays of the thin detector, irradiated in the neutron flux to be studied. The blackening density obtained by the β rays is then measured with a microdensitometer. The main interest of the method lies in the fact that one can obtain a power of resolution definitely superior to that which one obtains with other methods (G.M. detector-meter, boron ionization chamber, etc.). An example of an application is given. Reprint of a paper published in 'Comptes Rendus des Seances de l'Academie des Sciences', t. 23, sitting of May 12, 1952, p. 1969-1971.
[fr]On presente une methode de mesure de densite de neutrons. Elle consiste a faire l'autoradiographie, par rayons β du detecteur mince, irradie dans le flux de neutrons a etudier. On donne un exemple d'application. Reproduction d'un article publie dans les 'Comptes Rendus des Seances de l'Academie des Sciences', t. 23, seance du 12 mai 1952, p. 1969-1971.
[en] In an inverted triode, the gate is brought to a positive voltage and the plate, which serves as a control electrode, is negatively polarized. Under these conditions, the lamp operates as a dis-amplifying triode which can measure, with a very low consumption, negative DC voltages that can reach, according to the lamp model used, a few tens of kilovolts. The consumption does not exceed 10-9 A for the highest voltages, but decreases rapidly and can fall below 10-12 A for voltages of a few tens of volts. The lamp response is substantially linear over a significant portion of its characteristic response curve. Reprint of a paper published in 'Journal de Physique et le Radium', suppl. au no. 2, t. 13, Feb 1952, p. 28A-30A.
[fr]Dans une triode inversee, la grille est portee a une tension positive et la plaque, qui sert d'electrode de commande, est polarisee negativement. Dans ces conditions, la lampe fonctionne en triode desamplificatrice et permet de mesurer, avec une consommation tres reduite, des tensions continues negatives pouvant atteindre, suivant le modele de lampe utilisee, quelques dizaines de kilovolts. La consommation n'excede pas 10-9 A pour les tensions les plus elevees, mais decroit rapidement et peut descendre au-dessous de 10-12 A pour des tensions de quelques dizaines de volts. La reponse de la lampe est sensiblement lineaire sur une portion importante de sa caracteristique. Reproduction d'un article publie dans le 'Journal de Physique et le Radium', suppl. au no. 2, t. 13, fev. 1952, p. 28A-30A.
[en] This article provides a review of the different uses of fission products in the industry. It presents, first, the α and β radiations, their properties and their use in thickness gages and high voltage batteries. Then, the properties and applications of gamma radiations are described: gamma-graphy, thickness gages, monomers polymerization, food products sterilization, plastics reticulation, tracer techniques (wear detection, direct activation analysis, leak testing, diffusion measurements, study of materials deposition and crystallization processes..). Reprint of a paper published in 'Ingenieurs et techniciens', No. 72, December 1954
[en] It describes the study of working and drawing of uranium in γ phase. In a first part, the forgeable characteristics of uranium metal in the three different phases (α, β and γ) are compared by using BASTIEN-PORTEVIN method. The different experiments are testing the behaviour metal in each phase under different stresses and a temperature gradient as slow and shock traction, slow and shock compression, resilience, flexibility. Results show that optimum conditions for uranium drawing is uranium in phase γ. In a second part, it described the drawing method and process. The uranium rods obtained by this technique are of very good quality. In addition, the material wear is very low which permits a low production cost. Finally, the uranium rod physical properties are studied. (M.P.)
[en] The author proposes a rather brief overview of practical applications of artificial radio-elements in various industrial sectors. These applications concern the field of control through non destructive tests (gamma radiography analyses, absorption-based and backscattering-based thickness gauges) or measurements (flow rate or level measurements), various researches (regarding wear, fabrication of chemical products, mixtures, the origin of sulphur in cokes, or the action ammonium thiosulfate on the gloss of silver electrolytic deposit). Reprint of a paper published in 'Electronique Industrielle, No. 5, Nov-Dec 1955
Nuclear energy and its industrial applications. 1 - Atomic piles and radio-isotopes: The French atomic programme; The future of atomic energy; The Nuclear Study Centre of Saclay; Fundamental notions related to nuclear reactors; Neutron spectrometer used in the Saclay pile; Determination of the transport mean free path of thermal neutrons by measuring a complex length of diffusion; Electronic equipment used in the measurement of the diffusion length in graphite; The non destructive materials test using the oscillation method in the Chatillon pile; An analogue harmonic analyser; Recent progress in reactor control; Analogue calculators pile simulators; The preparation of artificial radio-elements; Problems faced in the prospecting of radioactive ores and used equipment; Radioactive aerosols and gases in the atomic industry; A fixed health monitoring installation at the Laboratoire de Haute Activite of Saclay
[en] This publication gathers several articles which address various aspects of atomic piles and radio-isotopes. More particularly, the addressed topics are: the future of atomic energy; a presentation of the Nuclear Study Centre of Saclay; an introduction to nuclear engineering; a study of the interaction of neutrons with various elements as a function of neutron velocity; a determination of the transport mean free path of thermal neutrons by measuring a complex length of diffusion; the electronic equipment used in the measurement of the diffusion length in graphite; the non destructive test of materials using the oscillation method in the Chatillon pile; an analogue harmonic analyser; recent progress in reactor control; analogue calculators pile simulators; the preparation of artificial radio-elements; the preparation of artificial radio-elements; a general review of radioactive survey equipment; radioactive aerosols and gases in the atomic industry; A fixed health monitoring installation at the High Activity Laboratory of Saclay. Reprint of a dossier published in 'L'Onde Electrique', Vol. XXXV, No. 343, October 1955, p. 783-947
[en] Inelastic scattering of the β- particles on the nucleus gives place to the emission of a X-ray Bremsstrahlung radiation. In view of possible industrial applications, we studied the slowing-down radiation of 90(Sr + Y) sources in various materials. This pure β- emitter of long period is in the fission products of uranium. Among of the industrial applications, these sources of weak X-rays energy can be used for the radiography of thin pieces, for measuring the thickness, or for the analysis by fluorescence. (M.B.)
[fr]La diffusion inelastique des particules β- sur les noyaux donne lieu a l'emission d'un rayonnement X de freinage. En vue de possibles applications industrielles, nous avons etudie le rayonnement de freinage des sources 90(Sr + Y) dans divers materiaux. Cet emetteur β- pur a longue periode se trouve dans les produits de fission de l'uranium. Parmi les applications industrielles a l'etude, ces sources de rayons X de faible energie peuvent etre utilisees pour la radiographie de pieces minces, la mesure d'epaisseurs, ou encore pour l'analyse par fluorescence. (M.B.)
[en] After a brief recall of a few concepts (mass number, charge and beams properties) and the description of used detectors (ionization chamber, Geiger-Mueller counter, scintillation counters), some radionuclides applications are described. In a first part, the well-developed applications are presented in three distinct groups: continuous applications such as β and γ gauges (determination hydrogen content of an hydrocarbon and content of an emulsion; discharge of static electricity), discontinuous applications such as radiography and autoradiography, wear or manufacture problems (distribution of a fungicide on tobacco) and finally, applications in research laboratories such as diffusion, exchange and solubility. It also describes the applications which are still in development such as the action of beams on matter (reticulation and degradation of polymers, monomers polymerisation, cold sterilization). In conclusion, few advices on the opportunity of such applications and the choice of the radionuclides are given. (M.P.)
[en] This work was undertaken to find the water conditions necessary for minimum corrosion in the mild steel thermal shield recirculating systems in NRX and NRU. This report contains the chemical and corrosion results obtained by operating three mild steel loops in which water at 85-95oF was recirculated through test sections located in J-rod positions in the NRX reactor. Lowest corrosion rates were found when the water was maintained at pH 10.5 with or without oxygen being present. In both cases the corrosion was general in nature and no pitting occurred. At pH 7 with oxygen present in the water severe pitting took place and the corrosion rate was several times higher than similar conditions without oxygen in the water. Under oxygen-free conditions the corrosion product was Fe3O4. At pH 7 and with 3-5 ppm of O2 in the water the corrosion product was a mixture of Fe3O4 and γ-Fe2O3. At high pH with oxygen present Fe3O4 predominated with some traces of Fe2O3. The systems tested may he listed in order of increasing corrosiveness: High pH with or without O2 in the water < water at pH 7 with no O2 present and continual purification < water with no O2 present and no purification or pH control < water at pH 7 with 3-5 ppm of O2 present. (author)