Publications and communications in the field of "Ionizing radiation" by authors of the French metrology network in 2015

Publications

AMIOT M.N., CHISTÉ V., FITZGERALD R., JUGET F, MICHOTTE C., PEARCE A., RATEL G. et ZIMMERMAN B.E., “Uncertainty evaluation in activity measurements using ionization chambers”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, 108-122.

BÉ M.-M., CHECHEV V.P. et PEARCE A., “Uncertainties in nuclear data evaluations”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, 66-72.

BÉ M.-M., ISNARD H., CASSETTE PH., MOUGEOT X., LOURENÇO V., ALTZITZOGLOU T., POMMÉ S., ROŽKOV A., AUERBACH P., SOCHOROVÁ J., DZIEL T., DERSCH R., KOSSERT K., NÄHLE O., KRIVOŠÍK M., OMETÁKOVÁ J., STADELMANN G., NONELL A. et CHARTIER F., “Determination of the 151Sm half-life”, Radiochimica Acta, 103, 2015, 619-626.

BORDY J.-M., “Monitoring of eye lens doses in radiation protection”, Radioprotection, 50, 3, 2015, 177-185.

CASSETTE PH., BOCHUD F. et KEIGHTLEY J., “Example of Monte Carlo uncertainty assessment in the field of radionuclide metrology”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, 42-50.

CLAIRAND I., GINJAUME M., VANHAVERE F., CARINOU E., DAURES J., DENOZIÈRE M., SILVA E.H., ROIG M., PRINCIPI S. et VAN RYCHEGHEM L., “First Eurados intercomparison exercise of eye lens dosemeters for medical applications”, Radiation Protection Dosimetry, 2015, 1-6.

DELAUNAY F., DONOIS M., GOURIOU J., LEROY E. et OSTROWSKY A., « Nouvelles chambres d’ionisation primaires du LNE-LNHB pour la détermination du kerma dans l’air dans un faisceau de cobalt-60 », Revue française de métrologie, 38, 2015, 3-10, DOI: 10.1051/rfm/2015005.

DUFRENEIX S., OSTROWSKY A., LE ROY M., SOMMIER L., GOURIOU J., DELAUNAY F., RAPP B., DAURES J. et BORDY J-M, “Using a dose-area product for absolute measurements in small fields: a feasibility study”, Phys. Med. Biol., 61, 2016, 650-662.

DZYSIUKA N., KADENKO I., GRESSIER V. et KONING A.J., “Cross section measurement of the 159Tb(n, γ)Tb160 nuclear reaction”, Nuclear Physics A, 936, 2015, 6-16.

FITZGERALD R., BAILAT C., BOBIN CH. et KEIGHTLEY J.D., “Uncertainties in 4πβ–γ coincidence counting”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, 86-96.

KOSSERT K. et MOUGEOT X., “The importance of the beta spectrum calculation for accurate activity determination of 63Ni by means of liquid scintillation counting”, Applied Radiation and Isotopes, 101, 2015, 40-43.

KOSSERT K., BRODA R., CASSETTE PH., RATEL G. et ZIMMERMAN B., “Uncertainty determination for activity measurements by means of the TDCR method and the CIEMAT/NIST efficiency tracing technique”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, 172-190.

LE ROY M., DUFRENEIX S., DAURES J., DELAUNAY F., GOURIOU J., OSTROWSKY A., RAPP B., SOMMIER L., VERMESSE D. et BORDY J.-M., “Establishment of dosimetric references in terms of dose-area product for small sizes MV X-ray beams”, Physica Medica, 31, 2015, 23-54.

LEPY M.-CH. et MENESGUEN Y., « Développement de la métrologie des photons X avec des sources monochromatiques accordables », Revue française de métrologie, 37, 2015, 13-20, DOI: 10.1051/rfm/2015002.

LÉPY M.-CH., PEARCE A. et SIMA O., “Uncertainties in gamma-ray spectrometry”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, 123-145.

LOIDL M., RODRIGUES M. et al., “Development and underground test of radiopure ZnMoO4 scintillating bolometers for the LUMINEU 0n2b project”, JINST, 10, 2015, P05007, DOI: 10.1088/1748-0221/10/05/P05007.

LOURENÇO V. et BOBIN CH., “Weighing uncertainties in quantitative source preparation for radionuclide metrology”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, 18-29.

LOURENÇO V., BOBIN CH., CHISTÉ V., LACOUR D., RIGOULAY F., TAPNER M., THIAM C. et FERREUX L., “Primary standardization of SIR-Spheres based on the dissolution of the 90Y-labeled resin microspheres”, Applied Radiation and Isotopes, 97, 2015, 170-176.

LOURENÇO V., LACOUR D., FERREUX L., LE GARRERES I., et MORELLI S., « Amélioration de la traçabilité des mesures environnementales de radioactivité via la production de matériaux marqués », Revue française de métrologie, 39, 2015, 3-13, DOI: 10.1051/rfm/2015010.

MOUGEOT X., “Reliability of usual assumptions in the calculation of β and ν spectra”, Physical Review C, 91, 055504, 2015, Erratum Physical Review C, 92, 059902(E).

NEDJADI Y., BAILAT C., CAFFARI Y., CASSETTE PH. et BOCHUD F., “Set-up of a new TDCR counter at IRA-METAS”, Applied Radiation and Isotopes, 97, 2015, 113-117.

SABOT B., CASSETTE PH., BONDIGUEL S., MICHIELSEN N. et PIERRE S., “Development of a primary thoron activity standard for the calibration of thoron measurement instruments”, Radiation Protection Dosimetry, 2015, 70-74.

THIAM C., BOBIN CH., MARINGER F.J., PEYRES V. et POMMÉ S., “Assessment of the uncertainty budget associated with 4πγ counting”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, S97-S107.

TZIKA F., HULT M., BURDA O., ARNOLD D., SIBBENS G., CARO MARROYO B., GÓMEZ–MANCEBO M.B., PEYRÉS V., MOSER H., FERREUX L., ŠOLC J., DRYÁK P., FAZIO A., LUCA A., VODENIK B., REIS M., TYMINSKI Z. et KLEMOLA S., “Interlaboratory comparison on 137Cs activity concentration in fume dust”, Radiation Physics and Chemistry, 116, 2015, 106-110, DOI: 10.1016/j.radphyschem.2015.03.043.

UNTERWEGER M., JOHANSSON L., KARAM L., RODRIGUES M. et YUNOKI A., “Uncertainties in internal gas counting”, Metrologia, 52, 3 (Uncertainties in Radionuclide Metrology), 2015, 156-164.

Communications

BACHAALANY M., LEBRETON L., HUSSON D. et HIGUERET S. ,“A new recoil proton telescope for energy and fluence measurement and characterization of fast neutron reference fields”, ANIMMA 2015, Lisbonne, Portugal, 20-24 avril 2015.

BORDY J.-M., “Proposal for a criterion to choose between a direct or indirect evaluation of eye lens doses”, International Conference on Individual Monitoring of Ionising Radiation, Bruges, Belgique, 20-24 avril 2015.

HUPE O., ROTH J., DENOZIÈRE M. et BORDY J.-M., “International Measurements at the pulsed radiation facility of LNHB according to the novel Technical Specification ISO/TS 18090-1: Characteristics of reference pulsed radiation – Part 1: Photon radiation” , Conference on Individual Monitoring of Ionising Radiation, Bruges, Belgique, 20-24 avril 2015.

MAIRE D., BOSSON G., GUILLAUDIN O., LEBRETON L. et MURAZ J.-F., QUERRE P., RIFFARD Q. et SANTOS D., “Neutron fluence and energy reconstruction with the LNE-IRSN/MIMAC recoil detector microTPC at 27 kev”, ANIMMA 2015, Lisbonne, Portugal, 20-24 avril 2015.

ADRIEN C., LE LOIREC C., DREUIL S., GREVENT D., BERTELOOT L., HABIB B. et BORDY J.-M., “Use of Rose criterion for image quality pre-optimization in computed tomography”, Optimisation in X-ray and Molecular Imaging (OXMI) 2015, Gothenburg, Suède, 28-30 mai 2015.

SHARROCK P., BRUMAS V., COULAUD J., FIALLO M., DEDIEU V., STIEN C. et BORDY J.-M., “Radiation-sensitive phantom with paramagnetic metal ions for 3-D MRI dosimetry of radiotherapy”, XXVe International Conference on Coordination and Bioinorganic chemistry, Session D, Complexes in human medecine and the environment., 50th anniversary of ICCBIC, Slovak academy of sciences, Smolenice, Slovaquie, 31 mai - 5 juin 2015.

BOBIN CH., “Calculation of extrapolation curves in the 4π(LS)β-γ coincidence technique with the Monte Carlo code Geant4”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

BOBIN CH., “Real-time radionuclide identification in γ-emitter mixtures based on spiking neural network”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

CASSETTE PH., “H-3 activity comparison between CPST, VNIIM and LNHB”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

CASSETTE PH., “Quench; a software package for the determination of quenching curves in liquid scintillation counting”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

DIMITROVA I., GEORGIEV S., PRESSYANOV D., SABOT B., MICHIELSEN N., BONDIGUEL S., MITEV K. et CASSETTE PH., “Influence of the type of CD case on the track density distribution in CDS exposed to thoron”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

FERREUX L., “Improvement of a low-level measurement system used at LNHB”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015

KELLETT M.-A., “Lu-177: DDEP evaluation of the decay scheme for an emerging radiopharmaceutical”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

LÉPY M.-C., “Determination of photon emission intensities in the decay of I-131”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

RODRIGUES M., “Determination of absolute photon emission intensities of Pb-210”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

MÉNESGUEN Y., “Measurement of partial L fluorescence yields of bismuth using synchrotron radiation”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

MOUGEOT X., “Relevance of usual approximations in beta calculations: systematic comparison with experimental shape factors”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

RODRIGUES M., “L X-ray satellite effects on the determination of photon emission intensities of radionuclides”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

SABOT B., “A new thoron atmosphere reference measurement system”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

THIAM C., “Investigation of the response variability of ionization chambers for the standard transfer of SIR-Spheres”, 20th International Conference on Radionuclide Metrology and its Applications, Vienne, Autriche, 8-11 juin 2015.

BORDY J.-M., ANDERSEN C., ANKERHOLD U., DEDIEU V., DELAUNAY F., DE POOTER J., COMPELL J., DUANE S., KAPSCH R.P, KOSUNEN A., MACHULA G., MARINELLI M., PALMANS H., PIMPINELLA M., VERONA RINATI G. et SOLC J., “An introduction to the metrology for radiotherapy using complex radiation fields – HLT09 EMRP Project”, 54es Journées scientifiques de la SFPM, Lille, France, 10-12 juin 2015.

DEDIEU V., STIEN C., SHARROCK P., FIALLO M., BRUMAS V., JAHANBIN T., SELABI R., COULAUD J. et BORDY J.-M., “Development of a new tissue equivalent material for 3D chemical dosimetry by MRI and feasibility of e-control service of TPS”, 54es Journées scientifiques de la SFPM, Lille, France, 10-12 juin 2015.

DELAUNAY F., PIMPINELLA M., DUANE S., BORDY J.-M., BOUCHARD H., CAPORALI C., DAURES J., DE COSTE V., DUFRENEIX S., GOURIOU J., GUERRA A.S., LE ROY M., OSTROWSKY A., RAPP B., SILVESTRE PATALLO I., SILVI L., SOMMIER L. et VERMESSE D., “Exploring Integral Quantities for high-energy x-rays small fields”, 54es Journées scientifiques de la SFPM, Lille, France, 10-12 juin 2015.

LE ROY M., DUFRENEIX S., DAURES J., DELAUNAY F., GOURIOU J., OSTROWSKY A., RAPP B., SOMMIER L., VERMESSE D. et BORDY J.-M., “Establishment of dosimetric references in terms of dose-area product for small sizes MV X-ray beams”, 54es Journées scientifiques de la SFPM, Lille, France, 10-12 juin 2015..

LOURENÇO V., BOBIN CH., CHISTE V., FERREUX L., LACOUR D., RIGOULAY F. et THIAM C., « Réalisation d’une référence nationale pour les microsphères de 90Y SIR-Spheres utilisées en radiothérapie interne sélective », 54es Journées scientifiques de la SFPM, Lille, France, 10-12 juin 2015

PIMPINELLA M., CAPORALI C., GUERRA A.S., SILVI L., DE COSTE V., PETRUCCI A., DELAUNAY F., DUFRENEIX S., GOURIOU J., OSTROWSKY A., RAPP B., BORDY J.-M., DAURES J., LE ROY M., SOMMIER L. et VERMESSE D., “Feasibility of using integral quantities to specify the beam quality of radiotherapy photon beams with small field sizes”, 54es Journées scientifiques de la SFPM, Lille, France, 10-12 juin 2015.

STIEN C., DEDIEU V., SHARROCK P., MACHU A., COULAUD J., FIALLO M., BRUMAS V. et BORDY J.-M., “Characterization of a new tissue-equivalent dosimeter for 3D dose distribution measurements”, 54es Journées scientifiques de la SFPM, Lille, France, 10-12 juin 2015.

BIAU A. et BORDY J.-M., « Mesure de la « dose » due à l’exposition professionnelle aux rayonnements ionisants : Objectifs et Evolutions », Congrès national de radioprotection SFRP, Reims, France, 18 juin 2015.

CHAPON A. et BORDY J.-M., « Vérification de l’étalonnage de radiamètres au moyen d’un accélérateur d’électron », Congrès national de radioprotection SFRP, Reims, France, 18 juin 2015.

RODRIGUES M., “A metallic magnetic calorimeter for measuring atomic fundamental parameter by X-ray spectrometry”, 16th International Workshop on Low Temperature Detectors (LTD-16), Grenoble, France, 24-28 juillet 2015.

BORDY J.-M., ANDERSEN C., ANKERHOLD U., DEDIEU V., DELAUNAY F., DE POOTER J., COMPELL J., DUANE S., KAPSCH R.-P., KOSUNEN A., MACHULA G., MARINELLI M., PALMANS H., PIMPINELLA M., VERONA RINATI G. et SOLC J., “Metrology for radiotherapy using complex radiation fields – HLT09 EMRP Project”, 17e Congrès international de métrologie, Paris, France, 21-24 septembre 2015.

AMIOT M.-N, “Development of a new type of dosimeter “Epresize®” for EPR-dosimetry adapted to subcentimeter field size”, Congrès EPR BioDose 2015, Hanover, États-Unis d'Amérique, 4-8 octobre 2015.

DUSCIAC D., BORDY J.-M., DAURES J. et BLIDEANU V., « High energy photon reference for radiation protection: technical design of the LINAC beam and ionization chambers; and calculation of monoenergetic conversion coefficients », 32es Journées des L.A.R.D. (Laboratoires Associés de Radiophysique et Dosimétrie), Centre d’Etudes Nucléaires de Bordeaux Gradignan (CENBG), Gradignan, France, 9-10 novembre 2015.

MENESGUEN Y., « Métrologie des coefficients d’atténuation massique », 11e Colloque Rayons X et Matière (RX 2015), Grenoble, France, 1-4 décembre 2015.

MENESGUEN Y., LEPY M.-CH., BOYER B. et NOVIKOVA A., « CASTOR, un instrument d’analyse combinée Réflectivité/ Fluorescence aux petits angles », 11e Colloque Rayons X et Matière (RX 2015), Grenoble, France, 1-4 décembre 2015.

MENESGUEN Y., LEPY M.-CH., LIDOVE G., RODRIGUES M. et TROUSSEL P., « Étalonnage en rendement absolu d’une photodiode avec un radiomètre cryogénique à substitution électrique », 11e Colloque Rayons X et Matière (RX 2015), Grenoble, France, 1-4 décembre 2015.

Abstract

Calorimetry is the best technique available to perform absolute measurement of absorbed dose. Graphite or water calorimeters are mainly used as reference for absorbed dose in water in most of the national metrology laboratories involved in ionizing radiations. LNE-LNHB has a long experience with graphite and tissue-equivalent calorimeters. Graphite calorimeter is nowadays the reference dosimeter for photon and electron beams at LNE-LNHB. Associated with a transfer procedure from graphite to water, it leads to the reference of absorbed dose to water which is the reference quantity for radiotherapy. A water calorimeter is being developed currently in order to compare different ways to establish the standards of absorbed dose to water at LNE-LNHB.

Key words

ionizing radiation metrology
calorimetry
absorbed dose
radiotherapy

Abstract

Most of the acquisition chains used in radionuclide metrology are based on NIM modules. These analogue setups have been thoroughly tested for decades now, becoming a reference in the field. Nevertheless, the renewal of ageing modules and the need for extra features both call for the development of new acquisition schemes based on digital processing. In this article, several technologies usable for instrumentation are first presented. A review of past and present projects is made in the second part, highlighting the fundamental role of dead-time management. The last part is dedicated to the description of two digital systems developed at LNE-LNHB. The first one has been designed for the instrumentation of a NaI(Tl) well-type crystal set-up, while the second one is used for the management of three photomultipliers in the framework of the TDCR method and as a part of the development of a digital platform for coincidence counting.

Key words

radionuclide metrology
digital instrumentation
dead-time
well-type crystal
coincidence counting
tdcr method

Abstract

In the field of radionuclide metrology, the TDCR method is a primary technique based on liquid scintillation using a threephotomultiplier instrumentation. The application of the TDCR model classically implemented in laboratories is investigated in the case of low-energy deposition in the liquid scintillator. For that purpose, the condition of stochastic independence between photomultipliers is introduced in order to express the classical probabilistic relations used for the detection efficiencies of coincidences. Experimentally observed in the case of 3H standardization, the time dependence arises when the coincidence resolving time is shorter than the time distribution of scintillation photons. The geometric dependence is also investigated because of the sensitivity of coincidence counting with the position of light emission inside the volume of the liquid scintillator. For that purpose, a new TDCR modeling using the Monte Carlo code Geant4 has been implemented in order to simulate the propagation of photons from their creation in the optical chamber to the production of photoelectrons in liquid scintillation counter. In both cases of stochastic dependence, the influence on the calculation of detection efficiencies and thus on the activity determination is presented. The new TDCR-Geant4 model was also developed to take into account Cherenkov emission; it has been applied to confirm the emission of Cherenkov photons subsequently created by Compton scattering in the photomultiplier windows. Using the TDCR-Geant4 model, a new primary technique is also presented by implementing the TDCR method using the Cherenkov emission. This new technique has been applied to the standardization of the short-lived radiopharmaceutical 11C (T1/2 about 20 min).

Key words

radionuclide metrology
tdcr method
liquid scintillation
CHERENKOV EFFECT
MONTE CARLO SIMULATION
GEANT4 CODE

Abstract

Individual dosimetry for exposure to beta particles in radiation protection deals essentially with the dosimetry of skin, i.e. the directional and individual dose equivalents at 0.07 mm depth for weakly penetrating radiation as indicated by the publications of ICRU and the ISO 6980. This article describes the procedure used to establish the primary standard in terms of absorbed dose to tissue of LNE-LNHB.

Key words

absorbed dose
Beta Radiation
radioprotection
metrology
Ionizing Radiation

Abstract

Monte Carlo codes have been widely used at the Laboratoire national Henri Becquerel (LNE-LNHB) for the last twenty years. They contribute to the establishment of national dosimetric references. In this paper, two main dosimetric quantities are calculated using Monte Carlo modelling in the field of medical physics: the absorbed dose and the kerma. Further discussions of the problems encountered are also presented.

Key words

monte carlo codes
dose
kerma
standard
dosimetry

Abstract

The manganese bath technique is the reference method for the calibration of neutron source emission rates. It is used to calibrate neutron sources using radionuclides in terms of neutron emission rate under 4p sr. The neutron source to be measured is immersed in a manganese sulphate solution where the emitted neutrons interact with the elements of the bath. In a typical configuration, approximately half of the neutrons lead to the creation of 56Mn via the 55Mn(n, γ) capture reaction. This radionuclide has a half-life of approximately 2.6 h and the bath reaches saturation when the number of nuclei decaying is equal to the number of nuclei created per unit time. The neutron emission rate from the source can then be deduced from the 56Mn activity at saturation, assuming proper modelling of the nuclear reactions occurring within the bath. The manganese bath facility has been recently refurbished in order to comply with appropriate safety and radioprotection regulations. This has lead to the upgrading of both the measurement methodology and the modelling of the bath, and a study on the development of a new detector for the on-line measurement of the manganese activity was developed. This new detector uses the 4πß-γ coincidence measurement method. The beta channel consists of photomultipliers tubes for the detection of Cerenkov light, and the γ channel uses a scintillation detector. The advantage of this measurement method is that it allows the determination of the bath activity without any prior calibration. A detector has been built and the results obtained have been compared to those from a primary measurement method already in use at LNE-LNHB. Furthermore, a comparison of the Monte-Carlo simulation results using GEANT4, MCNPX and FLUKA has been undertaken. This comparison revealed some discrepancies between the codes and uncertainty factors, such as the modeling of the neutron emission and the choice of the cross-section library.

Key words

neutron sources
emission rate
manganese bath
56mn
geant4
fluka
mcnpx
cerenkov-gamma coincidences

Abstract

In this paper we present the developments conducted at LNE-LNHB with the aim of improving the knowledge of the shapes of beta spectra, concerning the theoretical calculation of the spectra as well as their experimental determination by means of cryogenic detectors. The theoretical calculation comprises a screening correction that avoids the non-physical discontinuity present in the standard correction, as well as a correction of the exchange effect that is usually not taken into account and has a strong impact on the spectra of 63Ni and 241Pu. These calculations are compared with experimental spectra obtained with metallic magnetic calorimeters, a class of cryogenic detectors. The beta emitter is enclosed in the absorber of these detectors which offer high detection efficiency, high energy resolution and a very low energy detection threshold. The measured spectra of 63Ni and 241Pu confirm the correctness of the theoretical spectra, in particular the calculation of the exchange effect down to very low energies that have been explored for the first time.

Key words

beta spectrometry
beta spectra calculation
screening
exchange effect
cryogenic detector
metallic magnetic calorimeter

Abstract

Nowadays, the absorbed dose to water for kilovoltage X-ray beams is determined from standards in terms of air-kerma by application of international dosimetry protocols. New standards in terms of absorbed dose to water have just been established for these beams at the LNELNHB. A specific calorimeter was developed to do measurements at low depth in water, in order to fulfill the reference conditions required by the international dosimetry protocols for medium-energy X-ray. This new calorimeter was used to measure the absorbed dose rate in water at a depth of 2 cm for six medium-energy X-ray reference beams with a tube potential from 80 kV to 300 kV. The relative standard uncertainty obtained on the absorbed dose rate by water calorimetry is lower than 0.8%, whereas the one given by application of protocols based on airkerma is around 2.5%.

Key words

water calorimetry
absorbed dose
medium energy x rays

Abstract

The monitoring of environmental radioactivity is important for public health protection. In France, environmental radioactivity is specifically monitored by a network of certified laboratories. Indeed the Nuclear Safety Authority (ASN) delivers three to five year governmental agreements to each laboratory provided that it succeeds in proficiency tests (PTs) organized by the Institute for Radiological Protection and Nuclear Safety (IRSN). To ensure a direct traceability chain in radioactivity measurements, the Laboratoire National Henri Becquerel (LNE-LNHB), as the French national laboratory for radionuclide metrology, has been organizing national PTs for more than 40 years. LNE-LNHB also regularly realizes specific PTs to train the laboratories to the regulatory tests of IRSN. Most tests are based on aqueous solutions but there is a growing demand for tests on solid matrices to be measured by γ-spectrometry. Measurement of radionuclides from environmental samples includes a wide variety of matrix compositions and densities. Since 2009, LNE-LNHB is working on the production of suitable calibration reference materials to improve the traceability of environmental radioactivity measurements in France. To address this issue, LNELNHB intends to produce mixed γ-ray reference materials with a known mass activity and a composition as representative as possible of real environmental samples. The use of such materials will also improve the calibration of γ-spectrometry measurement systems due to a more accurate determination of the self-attenuation correction by measuring a known sample whose composition is close to the real one. This paper describes the development of the preparation protocol and the characterization of traceable matrices, spiked with various γ-ray emitters. A PT exercise has been organized with a low density matrix produced. The results of the participants are mentioned in this article.

Key words

spiked matrice
mixed gamma emitter
reference material
environmental radioactivity
proficiency test