Antineutrino emission and gamma background characteristics from a thermal research reactor

The detailed understanding of the antineutrino emission from research reactors is mandatory for any high sensitivity experiments either for fundamental or applied neutrino physics, as well as a good control of the gamma and neutron backgrounds induced by the reactor operation. In this article, the antineutrino emission associated to a thermal research reactor: the OSIRIS reactor located in Saclay, France, is computed in a first part. The calculation is performed with the summation method, which sums all the contributions of the beta decay branches of the fission products, coupled for the first time with a complete core model of the OSIRIS reactor core. The MCNP Utility for Reactor Evolution code was used, allowing to take into account the contributions of all beta decayers in-core. This calculation is representative of the isotopic contributions to the antineutrino flux which can be found at research reactors with a standard 19.75\% enrichment in $^{235}$U. In addition, the required off-equilibrium corrections to be applied to converted antineutrino energy spectra of uranium and plutonium isotopes are provided. In a second part, the gamma energy spectrum emitted at the core level is provided and could be used as an input in the simulation of any reactor antineutrino detector installed at such research facilities. Furthermore, a simulation of the core surrounded by the pool and the concrete shielding of the reactor has been developed in order to propagate the emitted gamma rays and neutrons from the core. The origin of these gamma rays and neutrons is discussed and the associated energy spectrum of the photons transported after the concrete walls is displayed.Comment: 14 pages, 11 figures, Data in Appendix A and B (13 pages

Online Monitoring of the Osiris Reactor with the Nucifer Neutrino Detector

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 an new tool to assess both the thermal power and the fissile content of the whole nuclear core and could be used by the Inter- national Agency for Atomic Energy (IAEA) to enhance the Safeguards of civil nuclear reactors. Deployed at only 7.2m away from the compact Osiris research reactor core (70MW) 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 0.85m3 detector remotely operating at a shallow depth equivalent to 12m 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 40760 electron antineutrinos, the mean number of detected antineutrinos is 281 +- 7(stat) +- 18(syst) electron antineutrinos/day, in agreement with the prediction 277(23) electron antineutrinos/day. Due the 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.Comment: 22 pages, 16 figures - Version

Guidelines of the French Society of Otorhinolaryngology (SFORL), short version. Extension assessment and principles of resection in cutaneous head and neck tumors

AbstractCutaneous head and neck tumors mainly comprise malignant melanoma, squamous cell carcinoma, trichoblastic carcinoma, Merkel cell carcinoma, adnexal carcinoma, dermatofibrosarcoma protuberans, sclerodermiform basalioma and angiosarcoma. Adapted management requires an experienced team with good knowledge of the various parameters relating to health status, histology, location and extension: risk factors for aggression, extension assessment, resection margin requirements, indications for specific procedures, such as lateral temporal bone resection, orbital exenteration, resection of the calvarium and meningeal envelopes, neck dissection and muscle resection

In situ SALS and volume variation measurements during deformation of treated silica filled SBR

International audienceOriginal in situ measurements of volume variation and small angle light scattering (SALS) are performed on silica filled Styrene Butadiene Rubber (SBR) during tensile tests. The influence of the silica treatment on the mechanisms involved is explored with sample carefully characterised and with the same filler dispersion. Two different types of silane are used as treatment, an alkoxy silane (so called covering agent) and a coupling agent which enables covalent bonds between the silica and the polymer matrix. It is shown that the coupling agent delays void formation in the samples and leads at intermediary strain to the reorganisation of the filler structure while the covering agent eases the void formation which also occurs without silica surface treatment