HELIOS is a large hemispherical outdoor simulation chamber (volume of 90 m3) positioned on the top of ICARE-CNRS building in Orléans.HELIOS is dedicated mainly to the investigation of the gas phase processes and radical chemistry under different conditions (sunlight, artificial light and dark). It is equipped with a large set of instrumentation: in-situ FTIR (up to 500 m path length), PTR-ToF-MS (Ionicon 8000), Aerodyne ToF-CIMS, ATD-GC-MS, UHPLC, IC, SMPS, Lopap, HCHO (Aerolaser), Spectroradiometer, Monitors (O3 and NOx), …. Other instruments for radicals measurements are under development (FAGE for HOx and CRDS for NO3).

Caractéristiques
HELIOS is a large hemispherical outdoor simulation chamber positioned on the top of the ICARE-CNRS building at Orléans (47°50’18.39N; 1°56’40.03E). The chamber is made of FEP film (250 μm thick) ensuring more than 90 % solar light transmission. The chamber is protected against severe meteorological conditions by a mobile protective housing which contains a series of Xenon lamps enabling experiments to be conducted also using artificial light. This special design makes HELIOS a unique platform in Europe where experiments can be made using both types of irradiation. HELIOS is dedicated mainly to the investigation of gas-phase processes and radical chemistry under different conditions (sunlight, artificial light and dark).

Large volume: 90 m3 : diameter : 6 m, height 3m, Projected horizontal surface area 55 m².
Low Surface / Volume ratio: 1.2 m-1
Low concentrations: in the order of ppb
Ambient temperature
Pressure: atmospheric (ultrapure air)
Relative humidity: variable
A laboratory of 110 m2 located under the room