Originally designed as a new nuclear reactor monitoring device, the Nucifer detector has successfully detected its first neutrinos. We provide the second shortest baseline measurement of the reactor neutrino flux. The detection of electron antineutrinos emitted in the decay chains of the fission products, combined with reactor core simulations, provides a new tool to assess both the thermal power and the fissile content of the whole nuclear core and could be used by the International Agency for Atomic Energy (IAEA) to enhance the Safeguards of civil nuclear reactors. Deployed at only 7.2 m away from the compact Osiris research reactor core (70 MW) operating at the Saclay research centre of the French Alternative Energies and Atomic Energy Commission (CEA), the experiment also exhibits a well-suited configuration to search for a new short baseline oscillation. We report the first results of the Nucifer experiment, describing the performances of the ∼ 0.85 m 3 detector remotely operating at a shallow depth equivalent to ∼ 12 m of water and under intense background radiation conditions. Based on 145 (106) days of data with reactor ON (OFF), leading to the detection of an estimated 40 760 νe, the mean number of detected antineutrinos is 281 ± 7(stat) ± 18(syst) νe/day, in agreement with the prediction 277 ± 23 νe/day. Due to the large background no conclusive results on the existence of light sterile neutrinos could be derived, however. As a first societal application we quantify how antineutrinos could be used for the Plutonium Management and Disposition Agreement. arXiv:1509.05610v4 [physics.ins-det]
Spallation neutron production in proton induced reactions on Al, Fe, Zr, W, Pb and Th targets at 1.2 GeV and on Fe and Pb at 0.8, and 1.6 GeV measured at the SATURNE accelerator in Saclay is reported. The experimental double-differential cross-sections are compared with calculations performed with different intra-nuclear cascade models implemented in high energy transport codes. The broad angular coverage also allowed the determination of average neutron multiplicities above 2 MeV. Deficiencies in some of the models commonly used for applications are pointed out.
Spallation neutron production in proton induced reactions on Pb targets at 0.8, 1.2, and 1.6 GeV has been measured at the SATURNE accelerator. Double-differential cross sections were obtained over a broad angular range from which averaged neutron multiplicities per reaction were inferred for energies above 2 MeV. The results are compared with calculations performed with a high energy transport code including two different intranuclear cascade (INC) models: it is shown that the Cugnon INC model gives a better agreement with the data than the Bertini one, mainly because of improved nucleonnucleon cross sections and Pauli blocking treatment. [S0031-9007 (99)09196-6] PACS numbers: 25.40.Sc, 24.10.Lx, 29.25.DzSpallation reactions can be used to produce high neutron fluxes by bombarding a thick heavy target with a high intensity intermediate energy proton beam. Interest in spallation reactions has recently been renewed because of the importance of intense neutron sources for various applications, such as spallation neutron sources for condensed matter and material physics [1-3], tritium production [4,5], accelerator-driven subcritical reactors for nuclear waste transmutation [6,7], or energy production [8]. Numerical calculation codes are available to design spallation sources. However, physics models used in these codes to describe elementary nuclear reactions above 20 MeV still suffer from large uncertainties. For instance, in [9], model predictions concerning neutron production double-differential cross sections were found to show big discrepancies between different codes. It was concluded that additional data were necessary, especially above 0.8 GeV, in order to improve and validate the models. Furthermore, neutron energy and angular distributions data are important for a correct simulation of the propagation of particles inside a spallation target and the geometrical distribution of the outgoing neutron flux.An extensive program has been conducted at the Laboratoire National Saturne to measure energy and angular distributions of neutrons produced by protons and deuterons with energies from 0.8 to 1.6 GeV on various thin and thick targets. In this Letter, we report on the measurement of double-differential cross sections obtained, at angles varying from 0 ± to 160 ± , with 0.8, 1.2, and 1.6 GeV proton beams on a 2-cm-thick Pb target.Neutron energy spectra were measured by two complementary experimental techniques, described in detail in [10,11], in a new experimental area [12].Low energy neutrons ͑E n # 400 MeV͒ were measured by time of flight between the incident proton, tagged by a plastic scintillator, and a neutron sensitive NE213 liquid scintillator [10]. Up to ten angles could be explored simultaneously using several neutron detectors. Six of them (cells of the multidetector DEMON [13]) were used between 4 and 400 MeV. The other four (called DENSE) allowed energy measurements with a reasonable error from 2 to 14 MeV. A pulse shape analysis was used for neutron-gamma discrimination. The energy resolution assoc...
The laser megajoule (LMJ) and the National Ignition Facility (NIF) plan to demonstrate thermonuclear ignition using inertial confinement fusion (ICF). The neutron yield is one of the most important parameters to characterize ICF experiment performance. For decades, the activation diagnostic was chosen as a reference at ICF facilities and is now planned to be the first nuclear diagnostic on LMJ, measuring both 2.45 MeV and 14.1 MeV neutron yields. Challenges for the activation diagnostic development are absolute calibration, accuracy, range requirement, and harsh environment. At this time, copper and zirconium material are identified for 14.1 MeV neutron yield measurement and indium material for 2.45 MeV neutrons. A series of calibrations were performed at Commissariat à l'Energie Atomique (CEA) on a Van de Graff facility to determine activation diagnostics efficiencies and to compare them with results from calculations. The CEA copper activation diagnostic was tested on the OMEGA facility during DT implosion. Experiments showed that CEA and Laboratory for Laser Energetics (LLE) diagnostics agree to better than 1% on the neutron yield measurement, with an independent calibration for each system. Also, experimental sensitivities are in good agreement with simulations and allow us to scale activation diagnostics for the LMJ measurement range.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.