Calculation of the ambient dose equivalent H*(10) from gamma-ray spectra obtained with scintillation detectors.

The measurement of the ambient dose equivalent H*(10) with automatic real-time radioactivity monitors using gamma-ray spectrometry provides valuable information at short integration times and serves as an alternative to conventional peak analysis of spectra. In this paper, a full methodology for the calculation of this quantity using Monte Carlo (MC) simulations is described and applied to real spectrometric measurements with LaBr(Ce) scintillation detectors. The methodology involves the calculation of the fluence-to-H*(10) conversion factors and a method for obtaining the fluence from gamma-ray spectra. The combination of these two elements makes it possible to calculate the H*(10). The obtained results are compared with the H*(10) measurements of a Geiger-Müller (GM) detector. Finally, the necessary activity concentration to produce a certain increment on the H*(10) is discussed for some isotopes. This is used to discuss the analysis capabilities of the spectrometric detectors when compared to GM ones.