Dependence of Titan's Aerosols Analogues Properties Generated in Radio Frequency Plasma Discharge on Their Conditions of Production

Abstract : Recent measurements done from the Cassini and Huygens space probes revealed that the solid particles produced by the atmospheric chemistry, should be present from the surface up to the ionosphere. Therefore, Titan's organic aerosols play a significant role in physical and chemical properties of the atmosphere and of the surface. Also, the determination of their properties and of their mechanisms of formation is of primary importance to understand the influence they have on the various environments of Titan. The PAMPRE experiment was developed to simulate in laboratory the Titan's atmosphere chemistry and to produces analogues of Titan's aerosols, with the aim to study the properties of the Titan's aerosols and their way of formation. This experiment consists in a low pressure Radio Frequency plasma discharge in a N2-CH4 gas mixture, allowing to produce analogues of Titan's aerosols in the gas phase without interaction with the reactor walls. We propose to present recent results obtained with this experiment, mainly dealing with the physical and chemical properties of the analogues produced. We will more particularly focus on the dependence of the chemical composition of the analogues on the operating conditions used for their production. A correlation of the particles properties with a few plasma characteristics, measured with different electrical and optical diagnostics, will be attempted. We will finally attempt to correlate these laboratory results with the known properties of the Titan's aerosols in order to try to bring additional information on the Titan's aerosols properties and their way of formation.