title: Monte Carlo calculation of entire in situ gamma-ray spectra.
abstract: We present a method for the synthesis of entire in situ gamma-ray spectra based on Monte Carlo calculations and measured data that characterize the detector properties. The method can serve for the determination of the effective depth of 137Cs in soil based on the information contained in the low-energy part of an in situ spectrum. Effective depth is defined as the depth of a plane distribution of 137Cs beneath the surface that reproduces the fluence energy and angular distribution at 1 m above the ground of gamma rays belonging to the real 137Cs distributions. We managed to reproduce the measured in situ spectra with our method and to demonstrate that the method allows the determination of the effective depth of 137Cs with a precision of 10(-2) m. The method requires minimal experimental characterization of the detector and is not sensitive to the details of the detector model and the soil composition and density employed in the Monte Carlo calculations.
authors.affiliation: J. Stefan Institute and Faculty of Mathematics and Physics, Jadranska 19, University of Ljubljana, P.O. Box 3000, Ljubljana 1000, Slovenia. andrej.likar@ijs.si
authors.forename: A
authors.initials: A
authors.lastname: Likar
authors.forename: T
authors.initials: T
authors.lastname: Vidmar
authors.forename: M
authors.initials: M
authors.lastname: Lipoglavsek
authors.forename: G
authors.initials: G
authors.lastname: Omahen
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis; D005720:Gamma Rays; D009010:Monte Carlo Method; D011848:Radioactive Pollutants / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013051:Spectrometry, Gamma
chemical_list: D002588:Cesium Radioisotopes; D011848:Radioactive Pollutants