Jérôme Béard

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Although air weapons are considerably lower in power than other firearms, there is increasing concern that serious injuries can result from their misuse. The present study was therefore carried out to improve understanding of the terminal ballistic behaviour of air rifle pellets. Pellets were fired into ballistic gel under a variety of conditions. The(More)
The pseudogap is a partial gap in the electronic density of states that opens in the normal (non-superconducting) state of cuprate superconductors and whose origin is a long-standing puzzle. Its connection to the Mott insulator phase at low doping (hole concentration, p) remains ambiguous and its relation to the charge order that reconstructs the Fermi(More)
The production of strongly magnetized laser plasmas, of interest for laboratory astrophysics and inertial confinement fusion studies, is presented. This is achieved by coupling a 16 kV pulse-power system. This is achieved by coupling a 16 kV pulse-power system, which generates a magnetic field by means of a split coil, with the ELFIE laser facility at Ecole(More)
Pulsed magnets are generally evaluated and compared in terms of the magnetic field they can achieve in combination with a bore size. However, in practice another criterion is equally important: the waiting time for a researcher in between two consecutive shots. The cooling time of pulsed magnets can range from a few minutes up to several hours, depending on(More)
Although bipolar jets are seen emerging from a wide variety of astrophysical systems, the issue of their formation and morphology beyond their launching is still under study. Our scaled laboratory experiments, representative of young stellar object outflows, reveal that stable and narrow collimation of the entire flow can result from the presence of a(More)
Magnetoresistivity ρ(xx) and Hall resistivity ρ(xy) in ultrahigh magnetic fields up to 88 T are measured down to 0.15 K to clarify the multiband electronic structure in high-quality single crystals of superconducting FeSe. At low temperatures and high fields we observe quantum oscillations in both resistivity and the Hall effect, confirming the multiband(More)
We present a new technique to measure pulsed magnetic fields based on the use of rubidium in gas phase as a metrological standard. We have therefore developed an instrument based on laser inducing transitions at about 780 nm (D2 line) in rubidium gas contained in a mini-cell of 3 mm × 3 mm cross section. To be able to insert such a cell in a standard(More)
The LNCMI has been involved since many years in the research and development of copper/stainless steel (Cu/SS) macrocomposite conductors for wire wound pulsed field magnets, generating magnetic fields up to 80 Tesla. The mechanical and electrical properties are adjusted to the magnet requirements by selecting the area fraction of the stainless steel(More)
Recent studies of attraction to sodium chloride baits suggest that diverse ant species forage for salt. We used experimental presentations of salt baits to test whether leaf cutter ants (Atta cephalotes) are attracted to and harvest salt-treated paper baits that offer no other resources. Atta foragers were most attracted to sucrose baits (positive control),(More)