164 research outputs found
Ligne de détection des neutrons issus du réacteur VENUS
No full textVue du haut de la ligne de détection des neutrons issus du réacteur VENUS du SCK-CEN de Mol en Belgique dans le cadre du projet GUINEVERE
Mesure de la température maximale des résidus chauds émis dans la réaction Ar + Au à 60 MeV/u
No full textThe work carried out in this thesis relates to the formation and decay by evaporating light particules of hot heavy residue produced in the 60 MeV per nucléon Ar + Au reaction. Using DéMoN facility has allowed to measure the initial temperature and the evaporated neutron multiplicity associated with heavy residue. Hotest observed residues sustain a 6 MeV temperature, have a 1.0 cm/ns recoil velocity, évapore about 22 neutrons and are produced with a non negligible cross section (50 mbarn). All the characteristics of this residue production are in good agreement with the predictions of a BNV calculation coupled with a statistical decay code.Le travail présenté dans cette thèse porte sur l'étude de la formation et de la désexcitation par evaporation de particules légères des noyaux chauds, les résidus, formés dans les réactions Ar + Au à 60 MeV par nucléon d'énergie de bombardement. L'utilisation du nouvel ensemble de détection DéMoN a permis d'estimer l'énergie d'excitation supportée par ces noyaux chauds à travers la mesure d'une part de leur température initiale, d'autre part de la multiplicité de neutrons évaporés qui leur est associée. Les noyaux les plus chauds observés ont une température de 6 MeV, une vitesse de recul de 1.0 cm/ns, évaporent en moyenne 22 neutrons et ont une section efficace de production d'environ 50 mbarn. La comparaison des résultats expérimentaux avec les prédictions d'un code de type B.N.V a permis d'associer la production de ces résidus à des collisions binaires dissipatives et des paramètres d'impact intermédiaires
SCALP: Scintillating ionization chamber for ALPha particle production in neutron induced reactions
No full textND 2016: International Conference on Nuclear Data for Science and TechnologyInternational audienceThe SCALP collaboration has the ambition to build a scintillating ionization chamber in order to study and measure the cross section of the α-particle production in neutron induced reactions. More specifically on 16O and 19F targets. Using the deposited energy (ionization) and the time of flight measurement (scintillation) with a great accuracy, all the nuclear reaction taking part on this project will be identif
SCALP: Scintillating ionization chamber for ALPha particle production in neutron induced reactions
No full textThe SCALP collaboration has the ambition to build a scintillating ionization chamber in order to study and measure the cross section of the α-particle production in neutron induced reactions. More specifically on 16O and 19F targets. Using the deposited energy (ionization) and the time of flight measurement (scintillation) with a great accuracy, all the nuclear reaction taking part on this project will be identify
Scintillation properties of N2 and CF4 and performances of a scintillating ionization chamber
No full textInternational audienceIn this work, we studied the emission yields, decay times and coincidence resolving times (CRT) of two gases, nitrogen (N2) and tetrafluoromethane (CF4), used for particle detection in the context of fission products measurement. The setup was made of an ionization chamber and two photomul-tiplier tubes (PMTs) placed front-to-front on each side of the active zone of the chamber. Using the photomultiplier tubes, the number of photoelectrons (phe) converted at the photocathodes from the scintillation processes in each gas were quantified and the scintillation time spectra were recorded. An scintillation emission yield of 24 phe MeV −1 with a decay time of τ d = 2.5 ns in N2, and 225 phe MeV −1 with τ d = 6.2 ns for CF4, have been measured. With our setup , the coincidence resolving time (σ values) between the two PMTs have been measured at 1.4 ns and 0.34 ns for N2 and CF4 respectively, using alpha particles
FALSTAFF : a New Tool for Fission Fragment Characterization
No full textNeutron for Science/SPIRAL2International audienceThe future Neutron For Science (NFS) facility to be installed at SPIRAL2 (Caen, France) will produce high intensity neutron beams from hundreds of keV up to 40 MeV. Taking advantage of this facility, data of particular interest to the nuclear community, in view of the development of fast reactor technology, will be measured. The development of an experimental setup called FALSTAFF for a full characterization of actinide fission fragments has been undertaken. Fission fragment isotopic yields and associated neutron multiplicities will be measured as a function of the neutron energy. Based on time-of-flight and residual energy technique, the setup will allow for the simultaneous measurement of the velocity and energy of the complementary fragments. The performance of the time-of-flight detectors of FALSTAFF will be presented and expected resolutions for fragment masses and neutron multiplicities, based on realistic simulations, will be shown
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