The data allow tracking of the efficiency variations due to contaminants and their removal by the decontamination. The removal of contaminants appear to slightly increase the efficiency in the UV and to slightly decrease it in the optical. Note however that the contaminants also introduce spatial dependencies in the flat fielding. The results of decontamination on the photometric accuracy will be addressed in a separate report. Here, we simply intend to note that contamination has effects smaller than 1 per cent on the mean flat field fluxes.
Contamination appears to decrease the UV efficiency and increase the efficiency in the optical.