TY - THES TI - Measure of the slowing down area of thermal state 1,45 eV neutrons in the graphite; Mesure de l'aire de ralentissement des neutrons dans le graphite de 1,45 eV a l'etat thermique AB - The life of a neutron emitted as a fast one within a moderating medium may be divided into two parts; at first it is slowed down colliding with the nuclei of the medium; later on, as soon as its energy is of the order of the thermal agitation energy, it diffuses until captured by some nucleus. As a matter of fact, dividing the evolution of a neutron into two phases, a slowing down phase and a diffusing phase is arbitrary, since the thermal equilibrium is attained stepwise. This report is intended to examine the means of inferring the distribution of thermal neutrons from the distribution of fast neutrons on the basis of the distribution of nascent thermal neutrons and of the law of scattering. (author) [French] La vie d'un neutron emis a l'etat rapide dans un milieu moderateur comprend 2 parties: au debut il se ralentit par chocs sur les noyaux du milieu; ensuite, lorsque son energie est de l'ordre de l'energie d'agitation thermique, il diffuse jusqu'a sa capture par un noyau. La separation de l'evolution d'un neutron en deux phases, phase de ralentissement, puis phase de diffusion, est, en realite, arbitraire; un neutron doit atteindre l'equilibre thermique progressivement. L'objet de ce rapport est de voir comment on peut deduire la repartition des thermiques de la repartition des rapides connaissant la repartition des thermiques naissants et la loi de diffusion. (au0010te. AU - "Robert, C [Commissariat a l'Energie Atomique, Saclay (France). Centre d'Etudes Nucleaires]" KW - "73 NUCLEAR PHYSICS AND RADIATION PHYSICS" KW - "ABSOLUTE COUNTING" KW - "BETA-MINUS DECAY" KW - "CADMIUM" KW - "CALIBRATION" KW - "CROSS SECTIONS" KW - "DATA COVARIANCES" KW - "DIFFUSION LENGTH" KW - "FAST NEUTRONS" KW - "FERMI AGE THEORY" KW - "FISSION FOIL DETECTORS" KW - "FOURIER TRANSFORMATION" KW - "GRAPHITE" KW - "INTEGRAL CALCULUS" KW - "MANGANESE ALLOYS" KW - "NEUTRON DENSITY" KW - "NEUTRON DIFFUSION EQUATION" KW - "NEUTRON FLUX" KW - "NEUTRON SOURCES" KW - "NEUTRON TRANSPORT THEORY" KW - "NICKEL ALLOYS" KW - "SPATIAL DISTRIBUTION" KW - "THERMAL NEUTRONS" KW - "THERMALIZATION" DO - https://doi.org/ UR - https://www.osti.gov/etdeweb/servlets/purl/20877809 PB - CY - France PY - 1956 DA - 1956-12-15 LA - French J2 - [] VL - C1 - CEA Saclay, 91 - Gif-sur-Yvette (France); Faculte des Sciences de l'Universite de Paris, 75 (France) C2 - C3 - CEA-R-674 C4 - C5 - Available from INIS in electronic form L3 - Other Information: TH: These sciences physiques; 5 refs ER -