More than a decade of gamma-ray observations of the sky have revealed that pulsars transfer a significant fraction of their kinetic energy to ultrarelativistic electron-positron pairs that can eventually propagate out to the interstellar medium. Despite being energetically subdominant in cosmic rays compared to protons and heavy nuclei, electrons and positrons easily radiate their energy and will lighten up the environments of particle accelerators in our Galaxy, thereby contributing significantly to its overall gamma-ray emission, especially at very high energies. The recent discovery of very extended gamma-ray halos around nearby pulsars has shown that leptons can be very efficiently confined around their sources, over large distances (>50 parsec) and long durations (>100000 years). How such a confinement is achieved remains uncertain. Possibilities include the injection of magnetic turbulence by kinetic instabilities from particles streaming away from the pulsar, resulting in a self-confinement of particles, and/or the injection of fluid turbulence on large scales by the supernova remnant expansion, followed by the cascading of turbulence to smaller scales where particle scattering can occur. Whatever is the mechanism for confinement, if our Galaxy harbors a large population of thousands of gamma-ray halos there may be profound implications for the exploration and interpretation of the gamma-ray sky. This applies notably to the search of the sources of most energetic cosmic-ray nuclei, especially in star-forming regions and the innermost parts of our Galaxy where most pulsars reside. The existence of large and long-lived pair halos should therefore be included when trying to build an accurate picture of the gamma-ray emission of our Galaxy. The goal of this project is to take the full measure of the gamma-ray halo phenomenon. By means of magnetohydrodynamic and particle-in-cell simulations we plan to explore the physics of pair confinement around pulsars to quantify if and how the phenomenon develops in a variety of galactic environments. Using existing gamma-ray observations we will probe the population of gamma-ray halos in our Galaxy over a broad energy range and at various scales, and firmly establish the place of these objects in the Galactic high-energy landscape. Last, based on this theoretical and observational knowledge, we will prepare for the observations of halos with forthcoming gamma-ray and radio instruments, developing tools and strategies for a further exploration of the phenomemon and to make sure that halos do not bias our intepretation of the measurements of other high-energy astrophysical phenonema.

The ENUBET (Enhanced NeUtrino BEams from kaon Tagging) project aims at building a monitored neutrino beam to reduce the uncertainty on the neutrino flux and cross section below 1%. Given the high rate of events expected, detector time resolution is a critical parameter for clean reconstruction of the events and strong reduction of the mixing of different events due to pile-up. Furthermore, sub-ns sampling in the far detector would allow one-to-one correlation between positrons tagged in the beamline and neutrinos tagged in the far detector, transforming ENUBET in the first “tagged neutrino beam”. We propose a 3-year R&D project to develop novel detector instrumentation based on the PICOSEC-Micromegas concept and demonstrate the impact of such detectors to New Physics searches by utilizing them to flavor and time tag neutrino beams. Possible exploitation of the PICOSEC-Micromegas technology will be investigated for both the ENUBET tagger and the neutrino detectors.This includes: - PICOSEC Micromegas detector embedded in an electromagnetic calorimeter (EMC), capable for accurate timing (~10 ps) of electron and gamma showers - PICOSEC Micromegas replacing the slow photon veto of ENUBET and acting also as a timing layer (T0-layers) at the ENUBET tagger for single MIP detection with timing better than 50 ps. - instrumentation of the hadron dump for muon monitor: this would allow for the first time in the history of neutrino beams to perform muon monitoring from pion decay at single particle level - Micromegas photodetector for time tagging at the neutrino detector. The PICOSEC-Micromegas concept consists in a “two-stage” Micromegas detector coupled with a Cherenkov radiator (MgF2), equipped with an appropriate photocathode. The drift gap is reduced to 200 μm while the applied electric field in this region (>10 kV/cm) is strong enough to produce electron multiplication. This configuration provides a large bandwidth for Cherenkov light production-detection in the extreme UV. Relativistic particles traversing the radiator produce Cherenkov photons which are simultaneously converted into electrons in the photocathode. Results obtained with small, single-anode prototypes yield a time resolution of 24 ps for relativistic muons and 44 ps for single UV photons. Those results have demonstrated that the desired timing performance can be achieved with our concept. However, there are several issues to be addressed, mostly concerning the scalability to large area detectors, including the development of the corresponding electronics, and of efficient and robust photocathodes for applications in high particle flux environments. In order to demonstrate in particle beams the required performance for each scenario, we will develop small (~10x10 cm2), modular prototypes. The main technical challenges to overcome is the choice of an efficient and robust photocathode and the production of Micromegas boards with segmented anode and planarity better than 10 μm, maintaining a small radiation length. In parallel, we will develop the necessary electronics to test and evaluate the prototypes. Front-end boards will be developed based on the optimization of a prototype, already tested successfully with a single anode prototype. The waveform digitization and precise time-tagging will be performed by electronics boards based on the SAMPIC circuit. The importance of precise timing in experiments operating at high luminosity colliding particle beams is already widely recognized, whilst 4D object reconstruction will be necessary in the future Particle Physics experiments in accelerators like the EIC and the FFC. The proposal aims at addressing critical points for the development of a sizable detector that can offer the necessary timing information. The project enhances the benefits of the PICOSEC Micromegas for PID as MIP detector bu talso as a timing layer embedded in a calorimeter.

Environmental exposure to neurotoxic metals is a global health concern affecting millions of people worldwide. Four metals (arsenic, lead, mercury and cadmium) have been listed among the ten chemicals of major public health concern by the World Health Organization. Manganese and uranium are two other elements of growing concern. They all cause neurotoxic effects. Recent research works have emphasized the consequences of extended low-level exposures to large populations. It is increasing recognized that the onset and progression of many age-related neurological diseases, including Alzheimer’s disease, may be triggered and/or accelerated by environmental exposure to metal contaminants. One solution to tackle this global issue is to better understand the molecular mechanisms involved in the neurotoxicity of environmental metals and to design targeted prevention strategies. However, despite decades of research, the underlying molecular mechanisms involved in neurodegenerative diseases remain poorly understood. We propose to assess a new mechanism for metal-induced neurotoxicity based on the direct interaction of metals with the synaptic cytoskeletal architecture and occurring at environmentally relevant concentrations. Such interaction would cause the disorganization of the synaptic structure, possibly by competition with essential metals binding-sites, resulting in synaptic impairments and neurological dysfunctions. We will characterize at the cellular and molecular levels the interactions of known environmental neurotoxic metals (arsenic, cadmium, lead, manganese, mercury, uranium) with synaptic cytoskeleton proteins (tubulin, actin), and will evaluate prevention strategies involving essential elements (copper and zinc). This interdisciplinary study will benefit from the complementarity of 3 research teams experts in: metal neurotoxicology (CENBG), neurobiology of synapses (IINS), metal-protein interactions (BIAM); and from the access to an outstanding instrumentation: synchrotron XRF (X-ray fluorescence) nano-imaging of metals correlated to STED (stimulated emission depletion) super-resolution microscopy of proteins, and native ESI-MS (electrospray ionization mass spectrometry) analysis of metal binding to proteins. Primary rat hippocampal neurons will be used as experimental model. The project has 4 aims: - The assessment of environmental metals synaptic toxicity; - The correlative nano-imaging of metals and cytoskeleton proteins in synaptic compartments; - The molecular characterization of metal-binding to cytoskeleton proteins; - The assessment of protective effects of essential metals against synaptic toxicity. Our project applies preferentially to the aetiology of Alzheimer’s disease because of the experimental cellular model chosen, hippocampal neurons, but the suggested mechanisms are likely to be involved in other neuro-pathologies such as autism and attention deficit disorders, depending on the period of exposure over the lifetime. We expect to show for the first time ever the presence of environmental metals in synapses and to describe the consecutive impairment of synaptic structures. These striking results will contribute to focus the attention of the scientific community, the public authorities and of the citizens on such environmental hazards. The comparison of different metals should help prioritize preventive and regulatory interventions.

The goal of the project is to develop techniques, in a staged approach, and push for optimization of a compact and high-brightness source of pulsed neutrons, using high-power lasers as a driver. In short, such lasers offer prospect for relatively inexpensive, extremely compact, collimated and fast (MeV) neutron sources, with the advantage of short duration, as demonstrated by our group in 2015 using our patented original concept. This would allow to satisfy the increasing demand for neutron sources, which will be difficult to meet with conventional facilities (accelerators) due to their associated cost (Billions of €). It will also enable a flexible experimental platform to uniquely study neutron interactions in the plasma state (for e.g. the nucleosynthesis of heavy elements in plasmas), which is not possible at conventional facilities where additional particle beams and energy sources to drive high-energy-density plasmas are usually missing. Establishing high-intensity, PetaWatt-class lasers as an attractive alternate for high-flux neutrons sources with relatively lower costs is timely. High-power laser facilities are indeed on a fast rise, and prove to be a very versatile tool to generate a wide range of secondary sources that can be used for scientific or societal applications, but none is yet geared to generate neutrons as a probing secondary source. This project is geared for the new, multi-PetaWatt (PW) Apollon laser users’ facility (financed in the frame of the large “Equipex/Investments for the Future programme” projects). It will associate four French laboratories, in partnership with IFIN-HH/ELI-NP (Romania), who have complementary expertise in laser-driven ion beams and nuclear physics. The project is expected to complement the capabilities of current neutron facilities to expand the field of neutron physics and applications (e.g. neutron radiography and spectroscopy). It will as well widen the applicability of laser-driven ion beam sources, all of which will benefit next-generation large-scale and high repetition rate (up to 10 Hz) facilities presently built in France, the EU and Asia.

More than one century after their discovery, the origin of cosmic rays is still a crucial issue in high energy astrophysics. The chemical composition of cosmic rays is dominated by protons below a particle energy of ~1 PeV, while heavier nuclei become important above it. This, together with the evidence that the transition between galactic and extragalactic cosmic rays takes place at particle energies largely exceeding the PeV, implies that the sources of galactic cosmic rays must be proton PeVatrons. The goal of this project is to identify the sources of PeV cosmic rays by means of multi-messenger (X-rays, gamma rays, and neutrinos) observations by current and future leading facilities.