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Simulation and dating of condensation processes

The current sophistication of thermodynamic models allows modelling of the gradual cooling of the gas within the protoplanetary disc at different heliocentric distances and the proposal of a sequence of condensation that satisfactorily describes the observable chemical and mineralogical features of chondrites. The detailed study of refractory inclusions, however, reveals several events during formation that are more complex and still poorly understood. To advance our understanding of these high-temperature condensation processes, we will use our newest generation of Nébulotron interfaced onto the beamline of the European Synchrotron Radiation Facility (ESRF) D2AM to synthesise analogues of the solar condensate. The analysis of the condensate by transmission electron microscopy (TEM) and in situ by wide- and small-angle X-ray scattering (WAXS and SAXS, at ESRF) will allow us to test different parameters independently (including gas composition, temperature, pressure, conditions of equilibrium or over-saturation, homogeneous vs. heterogeneous condensation), to clarify the conditions of the formation of refractory inclusions and to compare these conditions with the data from thermodynamic models. Applications to other stellar environments will be considered.

High precision 26Al-26Mg chronology : Mineral & bulk isochrons, model ages, initial heterogeneities and timing for their removal (Mishra & Chaussidon, 2012)

The evaporation-condensation cycle timeline is not known. Notably, we lack information on the time of the start of the condensation and its duration. Recent advances that we have made in the measurement of the isotopic composition of Mg and in the development of the 26Al chronometer provide access to very precise dating, using isochron ages and model ages, of the first condensates (refractory minerals and silicates) and of the successive events that they may have experienced prior to their imprisonment inside the chondrites. We will attempt to trace this history through ion probe dating of different types of condensates (including hibonites, CAIs, silicates, and others). This work corresponds to a portion of the ERC CEMYSS Project (see the CEMYSS description form).