Past exercises and publications

Coincidence summing correction

There are several ways of computing the coincidence summing corrections and each method has advantages and drawbacks (accuracy, easiness, speed, etc.) that were compared during this action.
In a first step, the comparison was restricted to point sources and to two radionuclides (134Cs and 152Eu). The same decay scheme and photon emission intensities were used by all the participants (NUCLEIDE database) to avoid bias linked to data discrepancies. The results were expressed as the coincidence summing correction factors for the multi-energetic nuclides for several energies and several source-to-detector distances.
In a second step, the exercise focussed on the case of volume sources using the same experimental setup as in the first part of the comparison, for the same two radionuclides (134Cs and 152Eu), but with different geometrical conditions: three volumes were considered, whose container diameter was smaller, equal or larger than the detector diameter. These containers were measured in three geometrical conditions: without absorber and with a Plexiglas or copper screen to examine the influence of X-rays. Experimental corrections were determined using the ratio between the activity derived from the processing of individual peaks (without correction) and the true activity of the source.

Exercise coordinator: Marie-Christine Lépy (LNE/LNHB, France)

Intercomparison of methods for coincidence summing corrections in gamma-ray spectrometry, by M.-C. Lépy and all the participants of the intercomparison, Applied Radiation and Isotopes 68 (2010) 1407-1412.

Intercomparison of methods for coincidence summing corrections in gamma-ray spectrometry—part II (volume sources), M.-C. Lépy, T. Altzitzoglou, M.J. Anagnostakis, M. Capogni, A. Ceccatelli, P. De Felice, M. Djurasevicf, P. Dryak, A. Fazio, L. Ferreux, A. Giampaoli, J.B. Han, S. Hurtado,A. Kandic, G. Kanisch, K.L. Karfopoulos, S. Klemola, P. Kovar, M. Laubenstein, J.H. Lee, J.M. Lee, K.B. Lee, S. Pierre, G. Carvalhal, O. Sima, Chau Van Tao, Tran Thien Thanh, T. Vidmar, I. Vukanac, M.J. Yang, Applied Radiation and Isotopes 70 (2012) 2112-2117.

Efficiency transfer

Four general Monte Carlo codes (GEANT3, PENELOPE, MCNP and EGS4) and five dedicated packages for efficiency determination in gamma-ray spectrometry (ANGLE, DETEFF, GESPECOR, ETNA and EFFTRAN) were checked for equivalence by applying them to the calculation of efficiency transfer (ET) factors for a set of well-defined sample parameters, detector parameters and energies typically encountered in environmental radioactivity measurements. The differences between the results of the different codes never exceeded a few percent and were lower than 2% in the majority of cases.

Exercise coordinator: Tim Vidmar (Jozef Stefan Institute, Ljubljana, Slovenia)

Testing efficiency transfer codes for equivalence, T. Vidmar, N. Çelik, N. Cornejo Díaz, A. Dlabac, I.O.B. Ewa, J.A. Carrazana González, M. Hult, S. Jovanovic, M.-C. Lépy, N. Mihaljevic, O. Sima, F. Tzika, M. Jurado Vargas, T. Vasilopoulou and G. Vidmar, Applied Radiation and Isotopes 68 (2010) 355-359

Monte Carlo codes intercomparison exercise

The aim of the exercise was to test the possible differences between Monte Carlo codes in order to assess the intrinsic uncertainties of such calculations, due to the different approaches to particle tracking and the nuclear and material data used for it. In accordance with its objective the exercise did not involve any reference to the experimental data and simply confronted the codes one with another, as they were applied to the calculation of full energy peak and total efficiencies for a precisely defined and very schematic model of a HPGe detector and the sample. Since there was no experimental data to compare the results of the codes against, this exercise only tested their mutual compatibility and not their absolute performance. The results of the exercise provided useful information for future intercomparisons involving the application of Monte Carlo codes to efficiency transfer and coincidence summing correction calculations.

Exercise coordinator: Tim Vidmar (Jozef Stefan Institute, Ljubljana, Slovenia)

An intercomparison of Monte Carlo codes used in gamma-ray spectrometry, T. Vidmar, I. Aubineau-Lanièce, M.J. Anagnostakis, D. Arnold, R. Brettner-Messler, D. Budjas, M. Capogni, M.S. Dias, L.-E. De Geer, A. Fazio, J. Gasparro, M. Hult, S. Hurtado, M. Jurado Vargas, M. Laubenstein, K.B. Lee, Y.-K. Lee, M.-C. Lépy, F.-J. Maringer, V. Medina Peyres, M. Mille, M. Moralles, S. Nour, R. Plenteda, M.P. Rubio Montero, O. Sima, C. Tomei, G. Vidmar, Applied Radiation and Isotopes 66 (2008) 764–768