In the rest, the only changeable parameter is refractive index of freon. Temperature influence on freon refractive index was measured experimentally. The parametrization
found to be:
n=n0-0.0005(T-20) where T is freon temperature in degrees Celsius
- n0=Sqrt(1+ 0.554*lamda^2/(lamda^2-5796)) where lamda is photon wavelength in nm taken at 20 degrees Celsius
+ n0=Sqrt(1+ 0.554*lamda^2/(lamda^2-5769)) where lamda is photon wavelength in nm taken at 20 degrees Celsius
Preliminary, the parametrization of refractive index versus temperature and photon energy is considered to be permanent.
As the reconstruction itself is only interested in mean refractive index Nmean C6F14, the most elegant solution is to store in OCDB this value, prcalculated in
AliHMPIDPrecprocessor. 2 measurements of temperature is avaiable from DCS: for inlet and outlet. They come in form of TObjArray of AliDCSValue, where AliDCSValue