New planetary atmosphere simulations: Application to the organic aerosols of Titan

The atmosphere of Titan partly consists of hazes and aerosol particles. Experimental simulation is one of the powerful approaches to study the processes which yield these particles, and their chemical composition. It provides laboratory analogues, sometimes called tholins. Development and optimization of experimental tools were undertaken in order to perform chemical and physical analyses of analogues under conditions free from contamination. A ''Titan aerosol generator'' was developed in the frame of the Cassini-Huygens mission, in order to produce Titan's aerosol analogues within conditions closer to those of the titanian atmosphere : cold plasma simulation system, low pressure and low temperature. The direct current (DC) glow discharge is produced by applying a DC voltage between two conductive electrodes inserted into the gas mixture -model of the studied atmosphere- at low pressure. A high-impedance power supply is used to provide the electrical field. All the system is installed in a glove box, which protect samples from any contamination. Finally the research program expected with this new material is presented. (C) 1997 COSPAR. Published by Elsevier science Ltd.