Characterization of PARIS LaBr3_3(Ce)-NaI(Tl) phoswich detectors upto EγE_\gamma ∼\sim 22 MeV

In order to understand the performance of the PARIS (Photon Array for the studies with Radioactive Ion and Stable beams) detector, detailed characterization of two individual phoswich (LaBr$_3$(Ce)-NaI(Tl)) elements has been carried out. The detector response is investigated over a wide range of $E_{\gamma}$ = 0.6 to 22.6 MeV using radioactive sources and employing $^{11}B(p,\gamma)$ reaction at $E_p$ = 163 keV and $E_p$ = 7.2 MeV. The linearity of energy response of the LaBr$_3$(Ce) detector is tested upto 22.6 MeV using three different voltage dividers. The data acquisition system using CAEN digitizers is set up and optimized to get the best energy and time resolution. The energy resolution of $\sim$ 2.1% at $E_\gamma$ = 22.6~MeV is measured for the configuration giving best linearity upto high energy. Time resolution of the phoswich detector is measured with a $^{60}$Co source after implementing CFD algorithm for the digitized pulses and is found to be excellent (FWHM $\sim$ 315~ps). In order to study the effect of count rate on detectors, the centroid position and width of the $E_{\gamma}$ = 835~keV peak were measured upto 220 kHz count rate. The measured efficiency data with radioactive sources are in good agreement with GEANT4 based simulations. The total energy spectrum after the add-back of energy signals in phoswich components is also presented.Comment: Accepted in JINS

Regiospecific Reduction of 4,6-Dinitrobenzimidazoles : Synthesis, Characterization, and Biological Evaluation

International audienceThe regiospecific reduction of 4,6-dinitrobenzimidazole derivatives leading to the corresponding 4-amino-6-nitrobenzimidazoles was studied. The identification of the formed product structures was accomplished by spectroscopic and X-ray diffraction data. The anticancer and antiparasitic activities of the synthesized compounds were examined, and promising activities against Toxoplasma gondii and Leishmania major parasites were discovered for certain 4,6-dinitrobenzimidazoles in addition to moderate anticancer activities of the 4-amino-6-nitrobenzimidazole derivatives against T. gondii cells. However, the tumor cell experiments revealed a promising sensitivity of p53-negative colon cancer cells to these compounds. © 2023 The Authors. Chemistry and Biodiversity published by Wiley-VHCA AG, Zurich, Switzerland

The PARIS cluster coupled to the BaFPro electronic module: data analysis from the NRF experiment at the γ\gammaELBE facility

International audience; The first cluster of the constructed PARIS calorimeter was assembled and tested atthe ELBE facility at HZDR, Dresden, Germany. The experiment was aimed at the evaluationof the performance of each detector separately as well as the whole PARIS cluster with discrete$\gamma$-ray energies seen by the PARIS ranging up to 8.9 MeV. As the detectors use phoswichconfiguration, with 2'' x 2'' x 2'' LaBr3(Ce) crystal coupled to 2'' x 2'' x 6'' NaI(Tl) one, greatcare must be taken during the data analysis process to obtain the best possible values for energyresolution. Two algorithms for data transformation from matrices created with slow vs fastpulse shaping to energy spectra were tested from which one was chosen for further analysis. Analgorithm for adding back energies of $\gamma$-rays scattered inside the cluster was prepared, as well.Energy resolution for $\gamma$-rays in 2–8 MeV range was estimated and is presented in this paper

Nanoparticles growth in dusty plasmas from organosilicon precursor

International audienceIn this work, plasma discharge has been generated from pure HMDSO precursor in low frequency reactor. It has been observed that a cloud of Nanoparticles could be formed in a plasma discharge for some deposition parameters such as discharge power, time and pressure. Discharge signal analysis have been used in order to investigate the effect of deposition parameters on the nanoparticles growth. The study of discharge signal analysis shows that the pulse frequency is strongly related to plasma composition. Their value shifted from about 170 Hz to 250 Hz according to deposited parameters. This shift has been attributed to the nanoparticles formation in the plasma reactor. On the other hand, Nanoparticles embedded in thin films have been characterized by EDX and FTIR spectroscopy in order to reveal the NP’s composition

Synthesis of nanopowders in a PECVD reactor from organosilicon precursor

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Dielectric properties of SiOx like films deposited from TMS/O-2 mixture in low pressure microwave plasma

International audienceIn this study, dielectric and physicochemical properties of thin films prepared in low pressure microwave plasma reactor have been investigated. The films have been deposited from tetramethylsilane or a mixture of tetramethylsilane and oxygen (TMS/O-2). The plasma discharge power and the working pressure in the reactor were kept constant and equal to 400 W and 1 mTorr, respectively. The deposition rate and refractive index have been found to decrease with increasing oxygen proportion in the mixture. For films deposited from TMS, the deposition rate and refractive index were about 800 angstrom/min and 1.55 respectively. Whereas, for films deposited from 90% of O-2 and 10% of TMS, their values were in the order of 50 angstrom/min and 1.47, respectively. When the oxygen rate in the mixture increases, FUR analysis shows more formation of Si-O-Si groups with a significant decrease of organics groups (such as Si-CH3 and -CHx). At high oxygen flow rate (90%) in the precursor mixture, the deposited films are SiOx-like structure. The dielectric constant value was close to 3.6 when the films are deposited using low oxygen proportion and close to 4.5 for films deposited with high O-2 rate in the precursor

Multimodal fusion of the finger vein, fingerprint and the finger-knuckle-print using Kernel Fisher analysis

Unimodal biometric have improved the possibility to establish systems capable of identifying and managing the flow of individuals according to the available intrinsic characteristics that we have. However, a reliable recognition system requires multiple resources. This is the main objective of the multimodal systems that consists of using different resources. Although multimodality improves the accuracy of the systems, it occupies a large memory space and consumes more execution time considering the collected information from different resources. Therefore we have considered the feature selection, that is, the selection of the best attributes that enhances the accuracy and reduce the memory space as a solution. As a result, acceptable recognition performances with less forge and steal can be guaranteed. In this paper we propose an identification system using multimodal fusion of finger-knuckle-print, fingerprint and finger's venous network by adopting several techniques in different levels for multimodal fusion. A feature level fusion and decision level is proposed for the fusion of these three biological traits. An optimization method for this multimodal fusion system by enhancing the feature level fusion is introduced. The optimization consists of the space reduction by using different methods.This work was supported by the Erasmus Mundus program EU-MARE NOSTRUM (EUMN) grant agreement number: 2011-4050/001-001-EMA2.info:eu-repo/semantics/publishedVersio

Improved method of S-alkylation of 2-mercaptobenzimidazole derivatives with trialkylphosphite

International audienceA new method of S-alkylation of 2-mercaptobenzimidazole derivatives has been developed by the condensation of these heterocycles with trialkylphosphite in the presence of phosphorus oxychloride giving the corresponding 2-S-alkylbenzimidazoles. The structure of the obtained products has been established by spectroscopic data

Effet de l’addition de l’oxygène sur les propriétés de couches minces déposées par plasma à partir de vapeurs de TMS

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Condensation of 7-nitroindole-2-carbohydrazide derivatives with ethyl acetoacetate

International audiencePyrazolylindolyl ketone derivatives were obtained by cyclization of the condensation products 7-nitroindole-2-carbohydrazide derivatives with ethyl acetoacetate. We have shown careful examination of spectroscopic data and the open-chain intermediate isolation as well as the identification of the formed compound structure