Emission de particules chargées légères induite par neutrons rapides (En = 25 – 65 MeV) sur noyaux lourds (209Bi et natU)

Les spectres énergétiques (sections efficaces doublement différentielles) de production de protons, deutons, tritons et particules alpha induite par des neutrons rapides sur 209Bi et natU sont présentées pour plusieurs énergies de neutrons incidents comprises entre 25 et 65 MeV. Les spectres ont été obtenus à 9 angles laboratoire entre 20° et 160° et extrapolés et interpolés à 10 autres angles afin de couvrir le domaine angulaire de 0 à 180°. Le dispositif expérimental et les procédures d'analyse des données incluant les corrections et la normalisation sont présentées et discutées. Sur base des sections efficaces doublement différentielles obtenues, les sections efficaces différentielles en énergie et en angle ainsi que les sections efficaces totales de production et les coefficients KERMA partiels associés sont également déduits. La thèse présente également des comparaisons aux rares mesures existantes dans la littérature ainsi qu'aux calculs théoriques basés sur les codes de réactions nucléaires INCL3, GNASH et TALYS. Tandis que l'INCL3 se base sur la cascade intranucléaire, les deux autres codes intègrent le modèle optique et les modèles de réactions directes, de prééquilibre, de fission et de noyaux composés dans un unique schéma de calcul. Finalement, sur base de l'ensemble des résultats obtenus depuis une dizaine d'années par le groupe, une vue nouvelle des sections efficaces totales de production et des coefficients KERMA partiels en fonction de la masse de la cible est proposée.(PHYS 3) -- UCL, 200

Light charged particle emission induced by fast neutrons (25 to 65 MeV) on /sup 59/Co

Double-differential cross sections (energy spectra) for the proton, deuteron, triton and alpha -particle production in fast neutron induced reactions on cobalt are reported for ten incident neutron energies between 25 and 65 MeV. Energy spectra were obtained at nine laboratory angles between 20 degrees and 160 degrees and extrapolated or interpolated to other ten angles covering uniformly the laboratory angular domain of 0 degrees to 180 degrees . The experimental set-up and procedures for data reduction including corrections and normalization are presented and discussed. Based on the measured double-differential cross sections, energy-differential and total cross sections are reported as well. Experimental cross sections are compared with similar available data from neutron- and proton-induced reactions. Theoretical calculations based on semiclassical exciton model and Hauser-Feshbach statistical theory (GNASH code) and intranuclear cascade model for nucleon-induced interactions (INCL3 code) were done and compared to the experimental results.Anglai

Experimental cross-sections for light charged particle emission induced by neutrons with energies between 25 and 65 MeV incident on Fe-nat, Co-59 Bi-209, and U-nat

14 Experimental double-differential cross-sections (d(2)sigma/dOmegadE) for fast neutron-induced proton, deuteron, triton, and alpha-particle emission on Fe-nat, Co-59. Bi-209, and U-nat are reported at several incident neutron energies between 25 and 65MeV for outgoing particle energies above the experimental energy detection thresholds. Angular distributions were measured at laboratory angles between 20degrees and 160degrees. Reliable extrapolated spectra were obtained at very forward (2.5degrees and 10degrees) and at very backward (170degrees and 177.5degrees) angles. Based on these experimental data, energy-differential (dsigma/dE), angle differential (dsigma/dOmega), and total cross-sections (UT) are reported for each detected particle species. (C) 2004 Elsevier Inc. All rights reserved

Light charged particle emission induced by fast neutrons with energies between 25 and 65 MeV on iron

Double-differential cross sections (energy spectra) for proton, deuteron, triton and alpha-particle emission in fast neutron-induced reactions on iron are reported for ten incident neutron energies between 25 and 65 Mev Energy spectra were obtained at nine laboratory angles between 20degrees and 160degrees and extrapolated or interpolated to ten other angles extending the angular distribution from 2.5degrees to 177.5degrees. The experimental set-up and the procedure for data taking and data reduction are briefly presented. Deduced energy-differential and total cross sections are also reported. Experimental cross sections are compared with data from proton-induced reactions on Fe-54 and Fe-56, and with our data from neutron-induced reactions on cobalt. Theoretical calculations of GNASH and TALYS reaction codes are also compared to the experimental data

Light charged particle production in the interaction of fast neutrons (25-65 MeV) with uranium nuclei

Energy spectra (double-differential cross sections) for proton, deuteron, triton, and alpha-particle production in fast neutron induced reactions on uranium are reported for several incident neutron energies between 25 and 65 MeV. The spectra were obtained at nine laboratory angles between 20degrees and 160degrees and extrapolated and interpolated to other ten angles suitably covering the laboratory angular domain of 0degrees to 180degrees. The experimental setup and procedures for data reduction including corrections and normalization are presented and discussed. Based on the obtained double-differential cross sections, energy-differential and total cross sections are deduced as well. Theoretical calculations are based on GNASH and TALYS nuclear reaction codes which integrate the optical model, direct, preequilibrium, fission, and statistical nuclear reaction models in one calculation scheme

Light charged particle emission in fast neutron (25-65 MeV) induced reactions on Bi-209

Experimental results concerning light charged particle (proton, deuteron, triton and alpha-particle) production in fast neutron induced reactions on bismuth are reported for several incident neutron energies between 25 and 65 MeV. Energy spectra (double-differential cross sections) were measured at 9 laboratory angles between 20degrees and 160degrees and extrapolated and interpolated to other 10 angles. The experimental set-up and procedures for data reduction including corrections and normalisation are shortly presented and discussed. Resulting energy-differential and total cross sections are reported as well. Experimental cross sections are compared to similar available data from neutron and proton induced reactions. Theoretical calculations are based on GNASH and TALYS nuclear reaction codes which integrate the optical model, direct, pre-equilibrium, fission and statistical nuclear reaction models in one calculation scheme. (C) 2003 Elsevier B.V. All rights reserved

Secondary light charged particle emission from the interaction of 25-65 MeV neutrons on uranium

Double-differential cross sections for light charged particle production in fast-neutron induced (n,px), (n,dx), (n,tx) and (n, alpha x) reactions on uranium were measured in the incident neutron energy range 25-65 MeV and at laboratory angles from 20 degrees to 160 degrees . In this paper, only a quick review of the experimental arrangement and data reduction procedures will be given. Preliminary inclusive emission spectra for hydrogen isotopes will be shown. From the double-differential cross sections, angle- and energy-differential cross sections as well as total production cross sections are deduced. The measurements are compared to nuclear model calculations which include preequilibrium and equilibrium decay mechanisms: the Liege intranuclear cascade model (INCL) and the GNASH nuclear data code.Anglai

Light charged particle production induced by fast neutrons (E/sub n / = 25-65 MeV) on /sup 209/Bi

This paper presents the experimental set-up and data reduction procedures regarding the measurement of double-differential cross sections for light charged particle production in fast neutron induced reactions (n,px), (n,dx), (n,tx) and (n, alpha x) on bismuth in the incident neutron energy range 25-65 MeV and at laboratory angles from 20 degrees to 160 degrees . Preliminary double-differential and energy-differential cross sections for hydrogen isotopes are presented.Anglai

Neutron-induced reaction cross-section measurements using a small multi-detector array and description of a large array

The experimental setup of Louvain-1a-Neuve (UCL-Belgium) used to perform light-charged particle production experiment in fast neutron-induced reactions is presented. A short description of the neutron modular detector DEMON is also given. DEMON is a detector array for neutrons emitted in heavy ion induced reactions at low to intermediate energies