Protactinium, a radioelement with unknown chemistry, is a key element : first actinide for which the 5f orbitals can be involved in chemical bonding, it is also naturally ocurring in envrionment, in the nuclear fuel cycle and also appear in the synthesis of innovative isotopes for medicine. Understanding the chemical behaviour of Pa in these compartments constitutes a great challenge especially since the basic chemistry of this element remains quite blurred ! In this project, we propose to switch to a new paradigm: "predict then experiment". Two main types of properties will be scrutinized, reactivity in terms of equilibrium constants between a set of ligands and protactinium(IV/V) and spectroscopy of protactium compounds. After an extensive methodological study and state-of-the-art theoretical predictions, we will set up prime electromigration, solvent extraction and spectroscopy (high-resolution XANES and laser spectrofluorimetry) experiments aiming at validating/improving the theoretical models and revealing this rare chemistry.

For numerous cancers, alpha emitters are particularly promising since they lead to a high treatment efficiency while sparing the surrounding healthy tissues. The REPARE project aims at bringing together research laboratories strongly involved in the field to develop new technologies in order to optimize production methods of innovative radioelements for nuclear medicine and more specifically for targeted alpha therapy. We propose to study and develop high power target systems able to exploit the very high beam intensities soon delivered by the linear accelerator of SPIRAL2. This would be used to synthesize the astatine-211 alpha emitter (used as a case study), to design a continuous online extraction system in the case of a liquid target, and to envisage the design of a radon/astate prototype generator allowing an optimal use of the astatine produced in the beta decay of radon. To achieve these objectives, it is planned to measure the production cross-sections of the harmful contaminants 210At and 209,210Po in the alpha and 6,7Li-induced reactions on bismuth targets as well as on lead-bismuth eutectic mixtures. These cross-section measurements will in part be essential in determining the suitability of high-power target designs. Two different types of design will be studied in detail: a rotating solid target system using convection and conduction cooling, and an ambitious liquid target system with an online extraction system of the produced 211At. In the case of direct production of astatine, hydro- and thermo-dynamical calculations will be carried out by the experts of the field that are present in our partnership in order to propose a solution that will also include the design of the system extracting the astatine from the irradiated targets. A prototype will be manufactured and tested in-beam. Feasibility studies will first be performed to identify any potential difficulties associated with the design of the liquid target. This includes aspects of beam characteristics, choice of target material and container, as well as cooling constraints. As a result of this work, thermal calculations and prototype design will be carried out. A continuous and on-line extraction system of the 211At will be proposed. The constraints associated to safety and radiation protection, particularly in the GANIL basic nuclear facility, will be addressed. The final aspect of this project concerns the indirect production of astatine-211, i.e. the study of 211At production by beta decay of 211Rn produced in lithium-induced reactions and having a half-life approximately twice as long as that of astatine, allowing a much more extended distribution range and a more appropriate use of 211At compared to the classical way. For this, studies of radon trapping in nano / microporous materials and optimization of experimental parameters will be performed. When possible, modeling of the collected data will also be done. The choice of material for the optimal elution of 211At from the point of view of its future use in clinical trials is critical and will be studied in detail. Lithium beam irradiation tests will be carried out with SPIRAL2. For this project as a whole, the TGIR GANIL grants a beam day per month of operation of SPIRAL2. Experiments will also be proposed and realized at ARRONAX and GANIL. The partnership built for this innovative project is composed of internationally recognized experts in their field of expertise: nuclear physics, use of particle beam, design of high power targets, thermal calculations, radiochemistry.

The neutrino is one of the most enigmatic ingredient of the standard model of particle physics. Because of its weak interaction with matter and despite enormous experimental progress, its nature and its fundamental properties remain unknown: Dirac / Majorana, CP violation, absolute mass scale, other flavors... Recent results from the t13 experiments Double Chooz, Daya Bay and RENO have uncovered an intriguing excess of events detected in the 4-6 MeV reconstructed energy range with respect to predictions. This spectral distortion may be a suggestion of discrepancies in models of antineutrino production in reactors. Moreover, three independent experimental anomalies (reactor anomaly, Gallium and LSND/ MiniBooNE) support the hypothesis of the existence of a new neutrino family, called sterile because not interacting through weak interaction. In this context, new data from a precise pure U235 Antineutrino spectrum are needed to resolve this open issue and to clarify the reactor anomaly. The SoLid project is an unique opportunity for the community to obtain sufficiently large and accurate data of neutrino flux at very short distance from a nuclear reactor, and then provide a reference measurement of pure 235U, essential for neutrino flux predictions used in current and future neutrino measurements. It proposes to confirm or refute the anomaly reactor and test ultimately the fourth sterile flavor. The strength of the SoLid proposal relies on both the antineutrino source and the technology of detection, which are unique. The experience takes place at BR2 research reactor of SCK-CEN (Mol, Belgium). It allows oscillation measurements at distance varying from 5.5 to 12 m from the core. In addition to this large range, the site is distinguished by its exceptionally low background environment and by having no-access to site constraint. The detector is based on an innovative technology of neutron detector, finely segmented. The use of 6LiF: ZnS layers allows a distinct discrimination of the neutron signal. In addition, the segmentation allows to locate the antineutrinos interactions and then effectively reject significant background sources. Combined with the favorable environment at BR2, our experiment provides an unprecedented sensitivity. Early 2015 a large-scale module 288kg (SM1) has been built and took “reactor ON” data during several days. This systems clearly demonstrates the capabilities of the segmented design of the detector, when combined with sophisticated data analysis techniques, leads to gains of orders of magnitude in background rejection. The physics run, with the full detector, will begin in October 2016 for a duration of two years minimum.This project is led by an international collaboration composed of eleven laboratories involving fifty physicists. Since the beginning, the three partners, Subatech, LAL and LPC have key contributions to the project: mechanical design, BR2 modelization, antineutrino spectra, Geant4/MCNP simulations and data analysis. This strong involvement allowed the coordinator to take responsablity of the SoLid analysis. Our proposal is to build 10 detection planes (320 kg) to increase the fiducial mass and the detector length, allowing us to probe the lower Dm2 phase space region. The French groups foresee to lead several specific studies into the oscillation framework to effectively probe the anomaly reactor, but also, comparing the pure U235 spectrum measured at BR2 with the data coming from the Double Chooz near detector to get an first insight in the “ 5 MeV bump” understanding. This specific contribution will consolidate our leadership in a experiment that promises to settle the question about the existence of sterile neutrino. In the longer term and for the international neutrino community, more precise neutrino flux measurements will allow to push the precision for future experiments.

Determining the thermal history of the early universe, as it evolved from its maximal temperature reached after inflation, is one of the main challenges at the intersection of cosmology and particle physics, with implications on open issues like the generation of the baryon asymmetry of the Universe and the nature of Dark Matter. The maximal reheating temperature and the associated particle degrees of freedom are currently poorly constrained, ranging from baryons,leptons and photons at the lower end to unestablished particle physics Beyond the Standard Model (BSM) much above the TeV scale at the upper one. The existence of this Hot Big Bang phase is however uncontroversial and the physics of thermal equilibrium is central in many BSM scenarios, e.g. to produce Dark Matter. The precision reached by direct detection attempts of BSM signatures in collider or astroparticle experiments and by indirect constraints, e.g. those coming from Cosmic Microwave Background measurements, is expected to increase dramatically over the next years. This then calls for much more precise theoretical determinations of processes in and out of thermal equilibrium, through which we can probe BSM physics throughout the thermal history of the universe. I then propose to take the most advanced framework for the determination of these rates, based on recent advancements in Thermal Field Theory I spearheaded, and make it available to the community. It will take the form of publicly released computer codes that use automation to evaluate thermal rates in any arbitrary particle physics model to high precision with end-user effort comparable to that of the time-honored, approximate methods still widely employed, such as Boltzmann equations with thermally-averaged cross sections. In more detail, we will automate production and interaction rates for light and heavy particles alike, following the templates of recent works. For what concerns light-particle rates, we will use my work on thermal gravitational wave production, which provided a proof-of-concept of Thermal Field Theory automation for light particles. It will be used as a basis for the automation of the contribution of 22 processes to the light particle rate. We will also automate the calculation of 12 processes in the ultrarelativistic regime, with the inclusion of the interference of multiple soft scatterings with the plasma constituents (LPM effect). This will be based on my recent work on the smooth connection of this rate with its counterpart in the relativistic (M~T) regime. We would then use these 22 and 12 modules to automate the generation of kinetic equations in arbitrary models, which are a key ingredient in studies of thermalisation during reheating. For massive particles, we would complement the relativistic 12 module with the recent work by Jackson and Laine, which provides a ready-for-automation algorithm for the evaluation of next-to-leading order corrections to the 12 processes. These include real 22 and 13 processes, as well as virtual thermal corrections to the 12 ones. These can be essential for infrared safety: their absence, as in current semi-automated codes for dark matter abundance, can cause substantial overestimation of the rates. Finally, we would conclude by employing the developed modules to showcase the power of the framework with a benchmark study in a carefully selected module, so as to also obtain new results at the frontier of the field. The proposed research requires the recruitment of a postdoc, that will take a leading role in the automation of massive particles and collaborate with me on the lighter-particle rates. In addition, funds for travel and computing are requested.

The innovative Opaque-Technology (OTech) derived from the LiquidO detection opens an unprecedented synergy between leading experts in medical and neutrino here proposing a new paradigm for medical imaging based on high precision antimatter ß+ detection. We propose to construct the first opaque liquid positron emission tomography system (LPET) in order to demonstrate and quantify its ability to fully characterise the annihilation pattern of both ß+ and ?-ß+ sources exploiting the latest machine learning techniques for maximal performance. The additional prompt-? will further improve the reconstructed annihilation origin while enabling the potential for direct tissue probing thanks to the accurate study of the positronium formation rate and lifetime dependent on the ß+ contact to the tissue structure including the development of metabolic disorders. Thus, our LPET prototype will explore the limits of today’s PET imaging while articulating a unique innermost tissue insight.