title: Calibration with MCNP of NaI detector for the determination of natural radioactivity levels in the field.
abstract: In view of assessing natural radioactivity with on-site quantitative gamma spectrometry, efficiency calibration of NaI(Tl) detectors is investigated. A calibration based on Monte Carlo simulation of detector response is proposed, to render reliable quantitative analysis practicable in field campaigns. The method is developed with reference to contact geometry, in which measurements are taken placing the NaI(Tl) probe directly against the solid source to be analyzed. The Monte Carlo code used for the simulations was MCNP. Experimental verification of the calibration goodness is obtained by comparison with appropriate standards, as reported. On-site measurements yield a quick quantitative assessment of natural radioactivity levels present ((40)K, (238)U and (232)Th). On-site gamma spectrometry can prove particularly useful insofar as it provides information on materials from which samples cannot be taken.
authors.affiliation: European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Nuclear Security Unit, Via Enrico Fermi 2749, 21027 Ispra VA, Italy. Electronic address: giorgia.cinelli@jrc.ec.europa.eu.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Cinelli
authors.affiliation: Department of Chemistry «Giacomo Ciamician», Alma Mater Studiorum University of Bologna, Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Tositti
authors.affiliation: Laboratory of Nuclear Engineering, Alma Mater Studiorum-University of Bologna, Via dei Colli 16, 40136 Bologna, Italy.
authors.forename: Domiziano
authors.initials: D
authors.lastname: Mostacci
authors.affiliation: Laboratoire de Physique des Radiations, Institut Supérieur Industriel de Bruxelles, H.-E. Paul-Henri Spaak, Rue Royale, 150, 1000 Bruxelles, Belgium.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Baré
mesh_terms: D002138:Calibration; D003198:Computer Simulation; D009010:Monte Carlo Method; D011834:Radiation Monitoring / Q000295:instrumentation*; D012974:Sodium Iodide; D013051:Spectrometry, Gamma
chemical_list: D012974:Sodium Iodide
keywords: In situ γ-spectrometry; Monte carlo simulation; NaI detector; Natural radioactivity