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[en] In the frame of the MiMAC project, the LPSC (Laboratoire de Physique Subatomique et de Cosmologie) has developed COMIMAC, a miniaturized and transportable table-top beam line, producing ions or electrons to make measurements of the “quenching” factor in ionization and detector calibration. The energy range of the COMIMAC beam facility starts from a few tens of eV up to 50 keV.
[en] Low-pressure gaseous TPCs are well suited detectors to correlate the directions of nuclear recoils to the galactic Dark Matter (DM) halo. Indeed, in addition to providing a measure of the energy deposition due to the elastic scattering of a DM particle on a nucleus in the target gas, they allow for the reconstruction of the track of the recoiling nucleus. In order to exclude the background events originating from radioactive decays on the surfaces of the detector materials within the drift volume, efforts are ongoing to precisely localize the track nuclear recoil in the drift volume along the axis perpendicular to the cathode plane. We report here the implementation of the measure of the signal induced on the cathode by the motion of the primary electrons toward the anode in a MIMAC chamber. As a validation, we performed an independent measurement of the drift velocity of the electrons in the considered gas mixture, correlating in time the cathode signal with the measure of the arrival times of the electrons on the anode.
[en] Several directional techniques have been proposed for a directional detection of Dark matter, among others anisotropic crystal detectors, nuclear emulsion plates, and low-pressure gaseous TPCs. The key point is to get access to the initial direction of the nucleus recoiling due to the elastic scattering by a WIMP. In this article, we aim at estimating, for each method, how the information of the recoil track initial direction is preserved in different detector materials. We use the SRIM simulation code to emulate the motion of the first recoiling nucleus in each material. We propose the use of a new observable, D , to quantify the preservation of the initial direction of the recoiling nucleus in the detector. We show that in an emulsion mix and an anisotropic crystal, the initial direction is lost very early, while in a typical TPC gas mix, the direction is well preserved.
[en] A debate on energy policy in France and more generally in Europe is made in this issue. Nuclear power, energy efficiency, evolution of the transportation sector, the energy demand, the carbon emissions are such points to be studied and discussed. (N.C.)
[en] After a presentation of different types of gaseous emissions (channelled and diffuse emissions), of the return on experience of methane diffuse emissions, and of the case of volatile organic compounds (VOC) emissions, this report proposes an overview of regulations, criteria and recommendations related to pollution reduction in different countries (United-Kingdom, Germany, Austria, Switzerland, Belgium, Italy, Spain, Denmark, Finland, Sweden, USA, Quebec and Canada, New-Zealand). It discusses regulations, criteria and recommendations related to the technical feasibility of biogas catchment and processing. It develops an assessment of health risks related to a reference re-development scenario, and finally proposes a methodology for the definition of an active catchment for closed sites according to several values or criteria deduced from European regulation and practices, and from the study of risks of a generic scenario and of the best available technologies.
[en] Because they are bright and distant, Gamma-ray Bursts (GRBs) have been used for more than a decade to test propagation of photons and to constrain relevant Quantum Gravity (QG) models in which the velocity of photons in vacuum can depend on their energy. With its unprecedented sensitivity and energy coverage, the Fermi satellite has provided the most constraining results on the QG energy scale so far. In this talk, the latest results obtained from the analysis of four bright GRBs observed by the Large Area Telescope will be reviewed. These robust results, cross-checked using three different analysis techniques set the limit on QG energy scale at EQG,1>7.6 times the Planck energy for linear dispersion and EQG,2>1.3×1011GeV for quadratic dispersion (95% CL). After describing the data and the analysis techniques in use, results will be discussed and confronted to latest constraints obtained with Active Galactic Nuclei