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International audience; Determination of actinide isotopic composition is one of the most important tasks accomplished under IAEA safeguards treaties for verification and inspection activities. Spectrometers based on HPGe detectors have traditionally been the detectors of choice for such systems with a large array of various data analysis codes developed specifically to suit the performance of these detectors. Over the past decade in this domain there has been interest in using medium resolution room temperature detectors based on CdZnTe and LaBr$_3$(Ce) crystals. Moreover, progress in analytical tools that could be applied to analyze worsened statistical quality spectral data has opened a wide range of possible applications where such compact detectors and absence of cryogenics are advantageous. In this paper we aim to provide a review on the recent advances in the domain of isotopic composition determination systems used as with traditional HPGe detectors as well as with medium resolution ones. We limit ourselves to the achievements in the European Union and divide our review in three parts. First, we provide an update on the current status of the French code IGA aimed at applications with traditional HPGe systems. Second, we present the recent results in the domain of isotopic composition determination codes development for medium resolution detectors, namely the codes MCSIGMA and CAMILA developed in the framework of a PhD project in Belgium. Third, we give an outlook on the current research activities conducted at CEA List Saclay in the domain of isotopic composition determination algorithms applied to medium resolution detectors.

International audience; The MAGIX code (a French acronym standing for Automatic Gamma and X-ray Measurement) is a software developed to analyze γ/X spectra on the topic of severe accident diagnosis. Indeed, the gamma spectra obtained after a severe reactor core accident are complex because they are composed of hundreds of lines of short-lived fission products and Fukushima accident demonstrated a lack in robustness of data interpretation during a crisis. MAGIX allows a complete and entirely automatic analysis of the spectra, with identification of radionuclides and calculation of activities. It can analyze spectra measured by detectors with excellent resolution such as HPGe detectors as well as detectors with medium resolution (e.g. CZT and LaBr3). For most detectors, the analysis of the spectra can be done without a detection efficiency curve because its process can include the calculation of a relative detection efficiency. MAGIX accepts spectra corresponding to any experimental setup (energy slope, energy range, resolution, absorber, etc.). However, these experimental conditions can have an impact on the quality of the results. Results on spectra simulated in different configurations showed that the analysis of the HPGe spectrum with the user defined efficiency and with the MAGIX detection efficiency were close. Furthermore, they also showed that the accuracy of activities was similar with increasing energy slopes but decreased with resolution degradation, with fewer correctly identified radionuclides in this case.

International audience; EasyMSI is a software tool for spatial and spectral visualization and processing of mass spectrometry imaging, with several modules providing user assistance for the interpretation of data. It has been developed by CEA-LIST during the Computis European project (2006-2009) and the Masda-Eye ANR project (2010-2012). EasyMSI can read MALDI and SIMS datasets in Analyze format (Applied Biosystems), GRD format (IonTof) and the imzML standard format for mass spectrometry imaging based on mzML. EasyMSI provides basic functionalities for data display and exploration (spectrum and image display, peak and pixel picking, zooming on spectra and images, ROI selection), and some more specialized treatments such as denoising spectra or structure analysis. EasyMSI offers the advantage to display MALDI data without binning. The user can choose tobin or not SIMS data, and the associated binning rate. As assistance to the interpretation of data, EasyMSI computes several indicators. The relative variance spectrum enhances peaks that have a highly contrasted space distribution. The Moranindex is an autocorrelation indicator adapted to detect thin local structures such as membranes, in images. The correlation spectrum associated to a given m/z brings out correlated m/z, often co-localised or complementary with the given m/z.EasyMSI is able to extract the peak list of the total spectrum, with parameterized criteria of extraction, to best adapt to the dataset peak shapes versus noise. Peak list can be used for molecule identification through the interrogation of biological databases. EasyMSI also includes clustering tools to perform spatial (i.e. pixel-based) classification or spectral (i.e. m/z-based) classification on peak lists or binned data. The K-means clustering is one of the simplest and fastest classification methods. The time for running a K-means clustering usually lasts only some seconds. The hierarchical clustering enables to performclustering inside a zone defined by a preceding clustering. The diffusion map method consists in reducing dimensionality by embedding data in a space in which data are more easily synthesized, and to do a clustering analysis in the reduced data.

International audience; Since 1998 CEA and COGEMA have been collaborating on new tools for isotope analysis by X- and gamma ray spectrometry with germanium detectors. The research program started with the determination of plutonium isotope composition, knowledge of which is essential in several branches of the nuclear industry. The newly developed application is characterised by an original approach and innovative gamma ray spectrometry techniques featuring: - a generic design (for example, no distinction is made between the analysis of the different isotopes of plutonium); - the systematic and automatic use of an atomic and nuclear database; - an advanced constrained-optimisation algorithm expressing physical knowledge in terms of constraints thus allowing robust analysis of very complex regions of interest; - the simultaneous determination of global efficiency curve and isotope ratios. For a user, this application takes form of an entirely automatic tool that accepts spectra corresponding to any experimental setup (gain, energy range, resolution, screen etc), without any detailed data on the setup being necessary. Moreover the user can control all intermediate results by the way of a user-friendly interface through an Internet browser. As the performance of the application proved satisfactory for plutonium isotopes in terms of robustness and precision, it was decided to extend it first to uranium enrichment, then to uranium and plutonium mixtures, and more generally to any actinide and contaminant mixtures. The development and evolution of the enhanced tool proceeded smoothly due to its initial generic design. In addition, a specific peak-location module was developed. This can recognize isotopes in a spectrum, and orientate the treatment to different classes such as 'plutonium spectrum', 'uranium spectrum', or 'mixture spectrum'. The application, called IGA, can now recognize and analyse a spectrum with actinides such as plutonium, uranium, neptunium and curium, together or alone, and in the presence of contaminants. The same set of algorithms has been also applied to another purpose, the characterisation of waste packages. A dedicated tool, called IGA/Sandra, has been developed for the CEA centre at Fontenay aux Roses. This tool is able to compute not only isotopic ratios and relative efficiency but also absolute activities, by normalisation with measured efficiency. Another domain of application of IGA is spectrum analysis from CdTe, CZT and NaI detectors. The peak location module already gives good results, since it is able to adapt itself to each type of detector and to find peaks in this type of spectrum.

International audience; Since 1998 CEA and COGEMA have been collaborating on new tools for isotope analysis by X- and gamma ray spectrometry with germanium detectors. The research program started with the determination of plutonium isotope composition, knowledge of which is essential in several branches of the nuclear industry. The newly developed application is characterised by an original approach and innovative gamma ray spectrometry techniques featuring: - a generic design (for example, no distinction is made between the analysis of the different isotopes of plutonium); - the systematic and automatic use of an atomic and nuclear database; - an advanced constrained-optimisation algorithm expressing physical knowledge in terms of constraints thus allowing robust analysis of very complex regions of interest; - the simultaneous determination of global efficiency curve and isotope ratios. For a user, this application takes form of an entirely automatic tool that accepts spectra corresponding to any experimental setup (gain, energy range, resolution, screen etc), without any detailed data on the setup being necessary. Moreover the user can control all intermediate results by the way of a user-friendly interface through an Internet browser. As the performance of the application proved satisfactory for plutonium isotopes in terms of robustness and precision, it was decided to extend it first to uranium enrichment, then to uranium and plutonium mixtures, and more generally to any actinide and contaminant mixtures. The development and evolution of the enhanced tool proceeded smoothly due to its initial generic design. In addition, a specific peak-location module was developed. This can recognize isotopes in a spectrum, and orientate the treatment to different classes such as 'plutonium spectrum', 'uranium spectrum', or 'mixture spectrum'. The application, called IGA, can now recognize and analyse a spectrum with actinides such as plutonium, uranium, neptunium and curium, together or alone, and in the presence of contaminants. The same set of algorithms has been also applied to another purpose, the characterisation of waste packages. A dedicated tool, called IGA/Sandra, has been developed for the CEA centre at Fontenay aux Roses. This tool is able to compute not only isotopic ratios and relative efficiency but also absolute activities, by normalisation with measured efficiency. Another domain of application of IGA is spectrum analysis from CdTe, CZT and NaI detectors. The peak location module already gives good results, since it is able to adapt itself to each type of detector and to find peaks in this type of spectrum.