The objective of the proposed project is the conversion of an indoor measured spectrum by in-situ *-spectrometry with a portable Ge detector to incident photon flux spectrum. For this, the measured spectrum must be stripped of the partial absorption and cosmic-ray events leaving only the events corresponding to the full absorption of a gamma ray.
In the proposed project the events corresponding to partial absorption in the detector will be determined by Monte Carlo simulations for different incident photon energies and angles using the GEANT code of CERN. Knowing the computed shapes of partial absorption continua deduced by the Monte Carlo simulations for differet photon energies. It is therefore possible to convert our measured spectra to total incident photon flux spectrum by applying the full absorption efficiency curve of the detector (which will be determined by calibrated point sources and/or by Monte Carlo simulations). The obtained results will be used as test of numerical simulations converting radionuclide concentrations in building materials to dose rates in an indoor environment.