Comparison of the conversion method with gravel unfolding to obtain dose values from photon spectra

Modern gamma-ray spectrometers based on solid-state scintillators are increasingly being used in fields where previously dosemeters were applied. From the spectra, precise fluence and dose information can be derived. The most important methods of doing this are investigated in detail; the conversion method, which is based on weighing functions; and unfolding, here using the GRAVEL algorithm. Both methods can be used to process any kind of spectra, regardless of the type of spectrometer employed. The GRAVEL algorithm is described in detail. The implementation of both methods is shown and results of examples are compared. Advantages and disadvantages of both techniques are discussed. For the first time, most precise conversion data up to 20 MeV are published, even extending the quantity H*(10) to this energy. They may serve for the improvement and harmonisation of dose rate measurements using scintillation spectrometers, e.g. those used in early warning systems.