CESAM chamber is a unique research infrastructure to investigate multiphase atmospheric processes including SOA formation, aerosol aging, cloud chemistry, etc. It is a 4.2 m3 stainless steel reactor, evacuable and temperature controlled (0°C to 60°C). It is equipped with a highly realistic irradiation system and with a comprehensive set of analytical instruments, including PTR-MS, AMS, CIMS, in situ long path UV-vis and FTIR, etc. Features that make this platform particularly suited to investigate multiphase processes are:

• very long submicronic aerosol lifetime

• ability to produce clouds

• protocol for mineral dust seeding

• high cleanliness level

• quality of the instrumentation