It is now well established that heterogeneous chemistry has a drastic impact on the tropospheric composition. The complex physicochemical processes involved in this chemistry include : phase exchange, surface reactions, reactions in condensed phase followed by transfer to the gas phase have to be quantified in order to be able to develop reliable atmospheric models, and thus have a better understanding of the tropospheric chemistry.
Integrating heterogeneous physicochemical parameters (kinetics constants, accommodation coefficients, complexe refractive indexes, hygroscopicity parameter etc…) requires new tools allowing to perform experiments in conditions as close as possible to natural ones. This is the goal of the simulation chamber called CESAM (which means Multiphase Atmospheric Experimental Simulation Chamber).
This simulation chamber has been designed specifically to perform in realistic conditions experiments involving several phases like organic particule, water droplets, mineral dust, soot, salts and gas phase.
CESAM is an atmospheric simulation chamber dedicated to the study of multiphase atmospheric processes such as the formation of secondary aerosol or gaseous compounds in cloud-phase reactivity. This is a stainless steel reactor with a volume of 4.2 m3, equipped of pumping devices allowing to make a secondary vacuum, particularly to limit the potential memory effects which may persist to another experience.
The particular design of this chamber allows :