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2. Development of a PCI Express Based Readout Electronics for the XPAD3 X-Ray Photon Counting Image

Author

Dawiec, A., Dinkespiler, B., Breugnon, P., Arnaud, K., Duval, P. -Y., Godiot, S., Hustache, S., Medjoubi, K., Berar, J. -F., Boudet, N., Morel, C., and Bompard, F.

Subjects
Physics - Instrumentation and Detectors
Abstract

XPAD3 is a large surface X-ray photon counting imager with high count rates, large counter dynamics and very fast data readout. Data are readout in parallel by a PCI Express interface using DMA transfer. The readout frame rate of the complete detector comprising 0.5 MPixels amounts to 500 images per second without dead-time., Comment: 17th Real-Time Conference on Real-Time Computer Applications in Nuclear, Particle and Plasma Physics, Lisbonne : Portugal (2010)

Published
2011

3. Far-infrared to millimeter astrophysical dust emission I: A model based on physical properties of amorphous solids

Author

Meny, C., Gromov, V., Boudet, N., Bernard, J. -Ph., Paradis, D., and Nayral, C.

Subjects
Astrophysics
Abstract

We propose a new description of astronomical dust emission in the spectral region from the Far-Infrared to millimeter wavelengths. Unlike previous classical models, this description explicitly incorporates the effect of the disordered internal structure of amorphous dust grains. The model is based on results from solid state physics, used to interpret laboratory data. The model takes into account the effect of absorption by Disordered Charge Distribution, as well as the effect of absorption by localized Two Level Systems. We review constraints on the various free parameters of the model from theory and laboratory experimental data. We show that, for realistic values of the free parameters, the shape of the emission spectrum will exhibit very broad structures which shape will change with the temperature of dust grains in a non trivial way. The spectral shape also depends upon the parameters describing the internal structure of the grains. This opens new perspectives as to identifying the nature of astronomical dust from the observed shape of the FIR/mm emission spectrum. A companion paper will provide an explicit comparison of the model with astronomical data., Comment: accepted in A&A, 21 pages, 9 figures

Published
2007
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6. New insights on the thermal dust from the far-infrared to the centimeter

Author

Dupac, X., Bernard, J. -P., Boudet, N., Giard, M., Lamarre, J. -M., Mény, C., Pajot, F., and Ristorcelli, I.

Subjects
Astrophysics
Abstract

We present a compilation of PRONAOS-based results concerning the temperature dependence of the dust submillimeter spectral index, including data from Galactic cirrus, star-forming regions, dust associated to a young stellar object, and a spiral galaxy. We observe large variations of the spectral index (from 0.8 to 2.4) in a wide range of temperatures (11 to 80 K). These spectral index variations follow a hyperbolic-shaped function of the temperature, high spectral indices (1.6-2.4) being observed in cold regions (11-20 K) while low indices (0.8-1.6) are observed in warm regions (35-80 K). Three distinct effects may play a role in this temperature dependence: one is that the grain sizes change in dense environments, another is that the chemical composition of the grains is not the same in different environments, a third one is that there is an intrinsic dependence of the dust spectral index on the temperature due to quantum processes. This last effect is backed up by laboratory measurements and could be the dominant one. We also briefly present a joint analysis of WMAP dust data together with COBE/DIRBE and COBE/FIRAS data., Comment: 4 pages, 2 figures, contribution to the proceedings of the Cologne-Bonn-Zermatt conference, held in Zermatt, Switzerland, Sept. 2003, eds: S. Pfalzner, C. Kramer, C. Straubmeier, and A. Heithausen, Springer-Verlag

Published
2003
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7. Inverse temperature dependence of the dust submillimeter spectral index

Author

Dupac, X., Bernard, J. -P., Boudet, N., Giard, M., Lamarre, J. -M., Mény, C., Pajot, F., and Ristorcelli, I.

Subjects
Astrophysics
Abstract

We present here a compilation of PRONAOS-based results concerning the temperature dependence of the dust submillimeter spectral index, including data from Galactic cirrus, star-forming regions and a circumstellar envelope. We observe large variations of the spectral index (from 0.8 to 2.4) in a wide range of temperatures (12 to 80 K). These spectral index variations follow a hyperbolic-shaped function of the temperature, large spectral indices (1.5-2.4) being observed in cold regions (12-20 K) while small indices (0.8-1.6) are observed in warm regions (35-80 K). Three interpretations are proposed: one is that the grain sizes change in warm and rather dense environments, another is that the chemical composition of the grains is not the same in different environments, a third one is that there is an intrinsic dependence of the dust spectral index on the temperature due to quantum processes., Comment: 2 pages, 1 figure, proc. of the SF2A conf. held in Bordeaux, France, June 2003, eds.: F. Combes, D. Barret and T. Contini, EdP-Sciences Conf. Series, p. 97

Published
2003

8. The Galactic dust as a foreground to Cosmic Microwave Background maps

Author

Dupac, X., Bernard, J. -P., Boudet, N., Giard, M., Lamarre, J. -M., Mény, C., Pajot, F., and Ristorcelli, I.

Subjects
Astrophysics
Abstract

We present results obtained with the PRONAOS balloon-borne experiment on interstellar dust. In particular, the submillimeter / millimeter spectral index is found to vary between roughly 1 and 2.5 on small scales (3.5' resolution). This could have implications for component separation in Cosmic Microwave Background maps., Comment: 4 pages, 1 figure, proceeding of the Multi-Wavelength Cosmology conference held in Mykonos, Greece, June 2003, ed. Kluwer

Published
2003
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9. Submillimeter Emission from Water in the W3 Region

Author

Wilson, C., Mason, A., Gregersen, E., Olofsson, A., Bergman, P., Booth, R., Boudet, N., Buat, V., Curry, C., Encrenaz, P., Falgarone, E., Feldman, P., Fich, M., Floren, H., Frisk, U., Gerin, M., Harju, J., Hasegawa, T., Hjalmarson, A., Juvela, M., Kwok, S., Larsson, B., Lecacheux, A., Liljestrom, T., Liseau, R., Mattila, K., Mitchell, G., Nordh, L., Olberg, M., Olofsson, G., Pagani, L., Plume, R., Ristorcelli, L., Sandqvist, Aa., Serra, G., Tothill, N., Volk, K., and von Scheele, F.

Subjects
Astrophysics
Abstract

We have mapped the submillimeter emission from the 1(10)-1(01) transition of ortho-water in the W3 star-forming region. A 5'x5' map of the W3 IRS4 and W3 IRS5 region reveals strong water lines at half the positions in the map. The relative strength of the Odin lines compared to previous observations by SWAS suggests that we are seeing water emission from an extended region. Across much of the map the lines are double-peaked, with an absorption feature at -39 km/s; however, some positions in the map show a single strong line at -43 km/s. We interpret the double-peaked lines as arising from optically thick, self-absorbed water emission near the W3 IRS5, while the narrower blue-shifted lines originate in emission near W3 IRS4. In this model, the unusual appearance of the spectral lines across the map results from a coincidental agreement in velocity between the emission near W3 IRS4 and the blue peak of the more complex lines near W3 IRS5. The strength of the water lines near W3 IRS4 suggests we may be seeing water emission enhanced in a photon-dominated region., Comment: Accepted to A&A Letters as part of the special Odin issue; 4 pages

Published
2003
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10. Submillimeter dust emission of the M17 complex measured with PRONAOS

Author

Dupac, Xavier, Giard, M., Bernard, J. -P., Boudet, N., Lamarre, J. -M., Meny, C., Pajot, F., Pointecouteau, E., Ristorcelli, I., Serra, G., Stepnik, B., and Torre, J. -P.

Subjects
Astrophysics
Abstract

We map a 50' x 30' area in and around the M17 molecular complex with the French submillimeter balloon-borne telescope PRONAOS, in order to better understand the thermal emission of cosmic dust and the structure of the interstellar medium. The PRONAOS-SPM instrument has an angular resolution of about 3', corresponding to a size of 2 pc at the distance of this complex, and a high sensitivity up to 0.8 MJy/sr. The observations are made in four wide submillimeter bands corresponding to effective wavelengths of 200, 260, 360 and 580 um. Using an improved map-making method for PRONAOS data, we map the M17 complex and faint condensations near the dense warm core. We derive maps of both the dust temperature and the spectral index, which vary over a wide range, from about 10 K to 100 K for the temperature and from about 1 to 2.5 for the spectral index. We show that these parameters are anticorrelated, the cold areas (10-20 K) having a spectral index around 2, whereas the warm areas have a spectral index between 1 and 1.5. We discuss possible causes of this effect, and we propose an explanation involving intrinsic variations of the grain properties. Indeed, to match the observed spectra with two dust components having a spectral index equal to 2 leads to very large and unlikely amounts of cold dust. We also give estimates of the column densities and masses of the studied clumps. Three cold clumps (14-17 K) could be gravitationally unstable., Comment: 16 pages, 4 figures, accepted June 2002 in Astronomy & Astrophysics

Published
2002
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16. The Galactic Dust as a Foreground to Cosmic Microwave Background Maps

Author

Dupac, X., Bernard, J.-P., Boudet, N., Giard, M., Lamarre, J.-M., Meny, C., Pajot, F., Ristorcelli, I., Burton, W. B., editor, Kuijpers, J. M. E., editor, van den Heuvel, E. P. J., editor, van der Laan, H., editor, Appenzeler, I., editor, Bahcall, J. N., editor, Bertola, F., editor, Cassinelli, J. P., editor, Cesarsky, C. J., editor, Engvold, O., editor, McCray, R., editor, Murdin, P. G., editor, Pacini, F., editor, Radhakrishnan, V., editor, Sato, K., editor, Shu, F. H., editor, Somov, B. V., editor, Sunyaev, R. A., editor, Tanaka, Y., editor, Tremaine, S., editor, Weiss, N. O., editor, and Plionis, Manolis, editor

Published
2004
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19. XPAD3 hybrid pixel detector applications

Author

Berar, J.-F., Boudet, N., Breugnon, P., Caillot, B., Chantepie, B., Clemens, J.-C., Delpierre, P., Dinkespiller, B., Godiot, S., Meessen, Ch., Menouni, M., Morel, C., Pangaud, P., Vigeolas, E., Hustache, S., and Medjoubi, K.

Published
2009
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25. PIXSCAN: Pixel detector CT-scanner for small animal imaging

Author

Delpierre, P., Debarbieux, F., Basolo, S., Berar, J.F., Bonissent, A., Boudet, N., Breugnon, P., Caillot, B., Cassol Brunner, F., Chantepie, B., Clemens, J.C., Dinkespiler, B., Khouri, R., Koudobine, I., Mararazzo, V., Meessen, C., Menouni, M., Morel, C., Mouget, C., Pangaud, P., Peyrin, F., Rougon, G., Sappey-Marinier, D., Valton, S., and Vigeolas, E.

Published
2007
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26. Distinguishing the local environments of Ga and Ge in amorphous (Ga2Se3)0.25(GeSe2)0.75 by anomalous X-ray scattering

Author

Klee, B. D, Stellhorn, J. R., Krbal, Miloš, Boudet, N., Chahine, G. A., Blanc, N., Pilgrim, W. C., Wágner, Tomáš, and Hosokawa, S.

Subjects
CHALCOGENIDE GLASSES, AXS, amorfní struktura, RMC, Chalkogenidová skla, AMORPHOUS STRUCTURE
Abstract

The amorphous structure of (Ga2Se3)0.25(GeSe2)0.75 is investigated using a combination of anomalous X-ray scattering (AXS) and Reverse-Monte-Carlo (RMC) modeling. It was confirmed that the Ga and Ge atoms can be found exclusively in the tetrahedral configuration. The average coordination number of the Se atoms is found to be 2.34(3) due to the presence of dative bonds. The formation of Ga/Ge-Ga/Ge so-called “wrong bonds” is discussed based on a set of RMC simulations. A strong Ga-Ga second neighbor correlations indicates the formation of Ga-Se clusters within the Ga-Ge-Se glass. Amorfní struktura (Ga2Se3)0.25(GeSe2)0.75 je zkoumána kombinací anomalního rentgenového rozptylu (AXS) a modelováním pomocí reverzního Monte-Carla (RMC). Bylo potvrzeno, že Ga a Ge atomy existují exkluzivně v tetraedrické konfiguraci. Průměrné koordinační číslo atomů Se je 2.34(3) kvůli přítomnosti dativních vazeb. Tvorba Ga/Ge-Ga/Ge takzvaných „homopolárních vazeb“ je diskutována pomocí RMC simulací. Silná korelace Ga-Ga v druhé koordinační sféře naznačuje tvorbu Ga-Se klastrů uvnitř Ga-Ge-Se skla.

Published
2018

27. XPAD: pixel detector for material sciences

Author

Basolo, S., Berar, J.-F., Boudet, N., Breugnon, P., Caillot, B., Clemens, J.-C., Delpierre, P., Dinkespiler, B., Koudobine, I., Meessen, C., Menouni, M., Mouget, C., Pangaud, P., Potheau, R., and Vigeolas, E.

Subjects
Radiation warning systems -- Mechanical properties, Synchrotron radiation sources -- Research, Scattering, Radiation -- Research, Business, Electronics, Electronics and electrical industries
Abstract

Currently available 2D detectors do not make full use of the high flux and high brilliance of third generation synchrotron sources. The XPAD prototype, using active pixels, has been developed to fulfill the needs of materials science scattering experiments. At the time, its prototype is build of eight modules of eight chips. The threshold calibration of [approximately equal to] 4 [10.sup.4] pixels is discussed. Applications to powder diffraction or SAXS experiments prove that it allows to record high quality data. Index Terms--Detector, pixel, powder diffraction, SAXS, synchrotron.

Published
2005

31. Non-auxetic/auxetic transitions inducing modifications of the magnetic anisotropy in CoFe2O4 thin films

Author

Martin, E., primary, Roulland, F., additional, Grenier, S., additional, Appert, F., additional, Juraszek, J., additional, Trassin, M., additional, Bouillet, C., additional, Chikoidze, E., additional, Arnold, C., additional, Berini, B., additional, Dumont, Y., additional, Colis, S., additional, Barre, S., additional, Versini, G., additional, Preziosi, D., additional, Leuvrey, C., additional, Blanc, N., additional, Boudet, N., additional, Pourroy, G., additional, Viart, N., additional, and Lefèvre, C., additional

Published
2020
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32. Reduction in the surface energy of liquid interfaces at short length scales

Author

Fradin, C., Braslau, A., Luzet, D., Smilgies, D., Alba, M., Boudet, N., Mecke, K., and Daillant, J.

Subjects
Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): C. Fradin [1]; A. Braslau [1]; D. Luzet [1]; D. Smilgies [2]; M. Alba [1]; N. Boudet [2]; K. Mecke [3]; J. Daillant [1, 4] Liquid-vapour interfaces, particularly those [...]

Published
2000
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33. Etude par diffraction des rayons X in situ sous rayonnement synchrotron de l’oxydation à haute température d’un alliage de zirconium

Author

Guillou, R., Le Saux, Matthieu, Guinebretière, René, Castelnau, O., Bechade, Jl., Menut, D., Boudet, N., Blanc, N., Arnaud, S., IRCER - Axe 3 : organisation structurale multiéchelle des matériaux (IRCER-AXE3), Institut de Recherche sur les CERamiques (IRCER), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and DERORY, BEATRICE

Subjects
[CHIM.MATE] Chemical Sciences/Material chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, [SPI.MAT] Engineering Sciences [physics]/Materials, [SPI.MAT]Engineering Sciences [physics]/Materials
Published
2019

34. Evolutions structurales au sein d'un alliage de zirconium oxyde a haute temperature en diffraction des rayons X in situ au rayonnement synchrotron

Author

Guillou, R., Bechade, Jl., Lesaux, M., Guinebretière, R., Castelnau, Olivier, Menut, D., Boudet, N., Blanc, N., Arnaud, S., CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), European Synchrotron Radiation Facility (ESRF), Centre National de la Recherche Scientifique (CNRS), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), and CADARACHE, Bibliothèque

Subjects
[PHYS.NUCL] Physics [physics]/Nuclear Theory [nucl-th], [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract

International audience; Pour certaines situations accidentelles hypothétiques rencontrées dans les réacteurs nucléaires à eau pressurisée (REP), la gaine en alliage de zirconium des crayons combustibles peut être exposée durant quelques minutes à de la vapeur d’eau à haute température (jusqu’à 1200°C), avant d’être refroidie puis trempée à l’eau. Le matériau de gainage subit alors de nombreuses évolutions structurales et métallurgiques : formation d’une couche d’oxyde (zircone), diffusion d’oxygène dans le métal sous-jacent, changements de phases du métal et de l’oxyde. Ces évolutions génèrent des contraintes internes à prendre en compte dans le cadre de l’étude de l’intégrité du matériau fragilisé par l’oxydation. Ces évolutions structurales sont à ce jour peu connues. Afin de suivre le processus d'oxydation à haute température d'un alliage de zirconium (le Zircaloy-4), nous avons réalisé des mesures in-situ de diffraction des rayons X sous rayonnement synchrotron à l’ESRF sur la ligne de lumière BM02 grâce à un four spécifique disponible sur cette ligne. Ce dernier a permis d’atteindre avec une bonne maîtrise les températures visées et surtout de contrôler précisément l’atmosphère.Ainsi, on a pu suivre sur des plaquettes de Zircaloy-4 les évolutions structurales et microstructurales des zircone monoclinique et quadratique (taille des cristaux, quantité relative de ces deux phases, …) en fonction de la température (entre 700 et 1100 degrés C) et du temps : durant le chauffage, l’oxydation à haute température et aussi le refroidissement.

Published
2019

35. Etude in-situ resolue en temps par diffraction des rayons X sous rayonnement synchrotron des evolutions structurales au sein d'un alliage de zirconium oxyde a haute temperature

Author

Guillou, R., Lesaux, M., Bechade, Jl., Guinebretière, R., Castelnau, Olivier, Menut, D., Boudet, N., Blanc, N., Arnaud, S., CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), Clinique Beau Soleil [Montpellier], European Synchrotron Radiation Facility (ESRF), Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), and CADARACHE, Bibliothèque

Subjects
[PHYS.NUCL] Physics [physics]/Nuclear Theory [nucl-th], [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], DRX, synchrotron, alliages de zirconium, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], oxydation haute temperature
Abstract

International audience; Dans certaines situations accidentelles hypothétiques dans les réacteurs nucléaires à eau pressurisée (REP), la gaine en alliage de zirconium des crayons combustibles, qui constitue la première barrière de confinement des produits radioactifs, peut être exposée durant quelques minutes à de la vapeur d’eau à haute température (jusqu’à 1200°C), avant d’être refroidie puis trempée à l’eau. Le matériau de gainage subit alors de nombreuses évolutions structurales et métallurgiques : formation d’une couche d’oxyde (zircone), diffusion d’oxygène dans le métal sous-jacent, changements de phases du métal et de l’oxyde. Ces évolutions génèrent des contraintes internes susceptibles de nuire à l’intégrité du matériau fragilisé par l’oxydation. Ces évolutions structurales sont à ce jour peu connues, notamment parce qu’elles sont difficiles à étudier dans les conditions dont il est question ici. Afin de suivre le processus d'oxydation à haute température d'un alliage de zirconium (le Zircaloy-4), nous avons réalisé des mesures in-situ de diffraction des rayons X sous rayonnement synchrotron sur la ligne de lumière BM02, CRG française à l’ESRF. Les évolutions structurales et microstructurales de la zircone en fonction de la température et du temps durant le chauffage, l’oxydation à haute température et le refroidissement de plaquettes en Zircaloy-4 ont été mesurées à l’aide d’un four prototype développé dans le cadre du projet ANR QMAX et disponible sur BM02. Celui-ci a permis d’atteindre avec une bonne maîtrise les températures visées et de contrôler précisément l’atmosphère. L’oxydation a été réalisée en faisant circuler à pression atmosphérique un mélange de O2 et He autour des échantillons. L’objectif était de suivre le processus, très rapide à haute température, avec une résolution en temps de l’ordre de la seconde, et de pouvoir analyser toute l’épaisseur d’oxyde, qui peut atteindre plusieurs dizaines de microns en quelques heures. Les clichés de diffraction ont été acquis à l’aide d’un détecteur 2D IMXPAD-WOS. Les mesures effectuées au chauffage dans une atmosphère contenant de l’oxygène ont mis en évidence la croissance d’une couche de zircone constituée d’un mélange évolutif des phases monoclinique et quadratique (augmentation de l’intensité des pics de diffraction associés) et ainsi que la croissance des cristallites de chacune des deux phases (diminution de la largeur à mi-hauteur des pics de diffraction) lors du chauffage. Des mesures effectuées lors de traitements isothermes à différentes températures entre 700 et 1100 degrés C ont permis de suivre, avec une résolution temporelle adaptée, les évolutions couplées, au cours du processus d’oxydation, de la taille des cristaux des zircone monoclinique et quadratique de la zircone et de la quantité relative de ces deux phases.

Published
2018

36. DISTINGUISHING THE LOCAL ENVIRONMENTS OF Ga AND Ge IN AMORPHOUS (Ga2Se3)(0.25)(GeSe2)(0.75) BY ANOMALOUS X-RAY SCATTERING

Author

Klee, B. D, Stellhorn, J. R., Krbal, Miloš, Boudet, N., Chahine, G. A., Blanc, N., Pilgrim, W. C., Wágner, Tomáš, Hosokawa, S., Klee, B. D, Stellhorn, J. R., Krbal, Miloš, Boudet, N., Chahine, G. A., Blanc, N., Pilgrim, W. C., Wágner, Tomáš, and Hosokawa, S.

Abstract

The amorphous structure of (Ga2Se3)0.25(GeSe2)0.75 is investigated using a combination of anomalous X-ray scattering (AXS) and Reverse-Monte-Carlo (RMC) modeling. It was confirmed that the Ga and Ge atoms can be found exclusively in the tetrahedral configuration. The average coordination number of the Se atoms is found to be 2.34(3) due to the presence of dative bonds. The formation of Ga/Ge-Ga/Ge so-called “wrong bonds” is discussed based on a set of RMC simulations. A strong Ga-Ga second neighbor correlations indicates the formation of Ga-Se clusters within the Ga-Ge-Se glass., Amorfní struktura (Ga2Se3)0.25(GeSe2)0.75 je zkoumána kombinací anomalního rentgenového rozptylu (AXS) a modelováním pomocí reverzního Monte-Carla (RMC). Bylo potvrzeno, že Ga a Ge atomy existují exkluzivně v tetraedrické konfiguraci. Průměrné koordinační číslo atomů Se je 2.34(3) kvůli přítomnosti dativních vazeb. Tvorba Ga/Ge-Ga/Ge takzvaných „homopolárních vazeb“ je diskutována pomocí RMC simulací. Silná korelace Ga-Ga v druhé koordinační sféře naznačuje tvorbu Ga-Se klastrů uvnitř Ga-Ge-Se skla.

Published
2019

39. Cartographie de l’espace réciproque à haute température sur la ligne BM02 à l’ESRF. Auto-organisation et transition de phase

Author

Guinebretière, René, Thune, Elsa, Huger, Marc, Babonneau, D., Ors, T., Michel, V., Castelnau, O., Arnaud, S., Blanc, N., Boudet, N., IRCER - Axe 3 : organisation structurale multiéchelle des matériaux (IRCER-AXE3), Institut de Recherche sur les CERamiques (IRCER), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), IRCER - Axe 4 : céramiques sous contraintes environnementales (IRCER-AXE4), and DERORY, BEATRICE

Subjects
[CHIM.MATE] Chemical Sciences/Material chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, [SPI.MAT] Engineering Sciences [physics]/Materials, [SPI.MAT]Engineering Sciences [physics]/Materials
Published
2018

40. Nanoscale electronic and structural properties in ferroelectric perovskite oxides from X-ray diffraction experiments

Author

Infante, IC., Bai, X., Volkova, Halyna, Nukala, P., Gemeiner, P., Guiblin, N., Dkhil, B., Guillot, J., Lenoble, D., Frontera, C., Hubault, C., Blanc, N., Boudet, N., Demange, Valérie, Karkut, Michael G., Boulle, Alexandre, Lemee, Nathalie, DERORY, BEATRICE, IRCER - Axe 3 : organisation structurale multiéchelle des matériaux (IRCER-AXE3), Institut de Recherche sur les CERamiques (IRCER), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.MATE] Chemical Sciences/Material chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, [SPI.MAT] Engineering Sciences [physics]/Materials, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

National audience

Published
2018

42. Large surface X-ray pixel detector

Author

Delpierre, P., Berar, J.F., Blanquart, L., Boudet, N., Breugnon, P., Caillot, B., Clemens, J.C., Mouget, C., Potheau, R., and Valin, I.

Subjects
Pixels -- Analysis, Crystallography -- Equipment and supplies, Business, Electronics, Electronics and electrical industries
Abstract

A large surface semiconductor photon counting pixel detector is being built. As a first step, this detector is optimized for X-ray crystallography. The aim is to provide a high dynamic range (> [10.sup.9]), high counting rate ([10.sup.7] ph/s per pixel), and fast image readout (3 ms). A full custom chip has been produced and tested, and results are presented. Prototypes of 6 [cm.sup.2] containing pixels of 330 x 330 [micro][m.sup.2] have been built together with a full fast readout system. These prototypes have been tested in the D2am beam line at the ESRF synchrotron (Grenoble, France) for photon energies between 10 and 24 KeV. For photon energies above 10 keV, the signal is separable from the noise. We give results on the efficiency as a0 function of the photon rate and the effect of the threshold on the efficiency in the region between the pixels. Furthermore, to demonstrate the large dynamic range, we made diffraction images. Index Terms--Crystallography, detector, instrumentation, pixels, X-rays.

Published
2002

43. High-temperature 3D-Reciprocal Space Mapping, phase transition and stress relaxation in pure zirconia

Author

Guinebretière, René, Gouraud, F., HUGER, Marc, Thune, Elsa, Örs, T., Michel, V., Castelnau, O., Arnaud, S., Blanc, N., Boudet, N., Axe 3 : organisation structurale multiéchelle des matériaux, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Axe 4 : céramiques sous contraintes environnementales (SPCTS-AXE4), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), and DERORY, BEATRICE

Subjects
[CHIM.MATE] Chemical Sciences/Material chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, [SPI.MAT] Engineering Sciences [physics]/Materials, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience

Published
2017

44. High-temperature 3D-RSM, phase transition and stress relaxation in pure zirconia

Author

Guinebretière, René, Ors, T., Michel, V., Castelnau, O., HUGER, Marc, Thune, Elsa, Blanc, N., Boudet, N., Axe 3 : organisation structurale multiéchelle des matériaux, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Axe 4 : céramiques sous contraintes environnementales (SPCTS-AXE4), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), and DERORY, BEATRICE

Subjects
[CHIM.MATE] Chemical Sciences/Material chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, [SPI.MAT] Engineering Sciences [physics]/Materials, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience

Published
2017

45. Domain engineering in Ferroelectric Tricolor Superlattices probed by X-ray diffraction

Author

Lemee, Nathalie, Boulle, Alexandre, Infante, IC., Hubault, C., Blanc, N., Boudet, N., Demange, Valérie, Karkut, Michael G., Axe 3 : organisation structurale multiéchelle des matériaux, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and DERORY, BEATRICE

Subjects
[CHIM.MATE] Chemical Sciences/Material chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, [SPI.MAT] Engineering Sciences [physics]/Materials, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience

Published
2017

46. Strains in thermally growing Cr2O3 films measured in situ using synchrotron X-rays

Author

Rakotovao, F., Tao, Zhaojun, Panicaud, Benoît, Grosseau-Poussard, Jean-Luc, Geandier, G., Renault, P.O., Goudeau, P., Boudet, N., Blanc, N., Vitoux, H., Gorges, B., Laboratoire des Sciences de l'Ingénieur pour l'Environnement - UMR 7356 (LaSIE), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Systèmes Mécaniques et d'Ingénierie Simultanée (LASMIS), Institut Charles Delaunay (ICD), Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers

Subjects
[PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph]
Abstract

International audience; This work takes place in the general context of a better understanding of materials degradation mechanisms in extreme environments. In particular, the aim of the present study was to correlate microstructural elements to growth stress magnitude evolution and stress release mechanisms for thermally grown chromia thin films on NiCr alloys. Strains in thermally grown oxides have been measured in-situ, as the oxides develop and evolve. Data have been acquired from oxides grown for different high temperatures evolutions on NiCr model alloys that form Cr2O3. Using synchrotron X-Ray at the ESRF (Beamline BM02) coupled with an induction furnace, Debye-Scherrer diffraction patterns from the oxidizing specimen were recorded in air at temperature between 700-1000°C and during cooling. The distortion of the diffraction rings was analyzed to yield the in-plane strain. Thermal stresses imposed on Cr2O3/NiCr by abruptly reducing the sample temperature for a period of time, exploiting the thermal expansion difference between oxide and substrate, showed noticeable subsequent stress relaxation by creep. Such a mechanism was monitored using time-dependent in situ measurements of strain relaxation in the oxide. The main results obtained from these experiments are the kinetic of the growth stress from the isothermal measurements (isothermal plateau), and the study of the stress release mechanism after the low-temperature jumps. In complement, the oxide microstructure development during the course of oxidation is also investigated from both the peaks intensity and width evolution. In all cases, the steady stage growth strain was relatively low and compressive. Different degrees of relaxation were also found on cooling depending on scale microstructure through the variation of the initial oxidation conditions. Results are compared with other reports of residual stresses evolution in Cr2O3 scales. © 2017 Trans Tech Publications, Switzerland.

Published
2017

50. Development of structural order during supercooling of a fragile oxide melt.

Author

Hennet, L., Pozdnyakova, I., Bytchkov, A., Price, D. L., Greaves, G. N., Wilding, M., Fearn, S., Martin, C. M., Thiaudière, D., Bérar, J.-F., Boudet, N., and Saboungi, M.-L.

Subjects
GLASS, CRYOSCOPY, OPTICAL diffraction, TEMPERATURE, THERMODYNAMICS
Abstract

The authors have studied the structural evolution of the fragile glass-forming liquid CaAl2O4 during supercooling from the stable liquid phase to the cold glass below Tg. The evolution is characterized by a sharpening of the first diffraction peak and a shortening of the average nearest-neighbor bond length around 1.25Tg, indicating an increase in the degree of both intermediate-range and short-range orders occurring close to the dynamical crossover temperature. The cooling curve developed a kink at this temperature, indicating a simultaneous change in thermodynamic properties. [ABSTRACT FROM AUTHOR]

Published
2007
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