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Search Results: 1 - 10 of 544476 matches for " N. M. Barriere "
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Soft gamma-ray optics: new Laue lens design and performance estimates
N. Barriere,L. Natalucci,N. Abrosimov,P. von Ballmoos,P. Bastie,P. Courtois,M. Jentschel,J. Knodlseder,J. Rousselle,P. Ubertini
Physics , 2009, DOI: 10.1117/12.826138
Abstract: Laue lenses are an emerging technology based on diffraction in crystals that allows the concentration of soft gamma rays. This kind of optics that works in the 100 keV - 1.5 MeV band can be used to realize an high-sensitivity and high-angular resolution telescope (in a narrow field of view). This paper reviews the recent progresses that have been done in the development of efficient crystals, in the design study and in the modelisation of the answer of Laue lenses. Through the example of a new concept of 20 m focal length lens focusing in the 100 keV - 600 keV band, the performance of a telescope based on a Laue lens is presented. This lens uses the most efficient mosaic crystals in each sub-energy range in order to yield the maximum reflectivity. Imaging capabilities are investigated and shows promising results.
Exploring plasma evolution during Sagittarius A* flares
Salome Dibi,Sera Markoff,Renaud Belmont,Julien Malzac,Nicolas M. Barriere,John A. Tomsick
Physics , 2015, DOI: 10.1093/mnras/stu599
Abstract: We present a new way of describing the flares from Sgr A* with a self-consistent calculation of the particle distribution. All relevant radiative processes are taken into account in the evolution of the electron distribution and resulting spectrum. We present spectral modelling for new X-ray flares observed by NuSTAR, together with older observations in different wavelengths, and discuss the changes in plasma parameters to produce a flare. We show that under certain conditions, the real particle distribution can differ significantly from standard distributions assumed in most studies. We conclude that the flares are likely generated by magnetized plasma consistent with our understanding of the accretion flow. Including non-thermal acceleration, injection, escape, and cooling losses produces a spectrum with a break between the infrared and the X-ray, allowing a better simultaneous description of the different wavelengths. We favour the non-thermal synchrotron interpretation, assuming the infrared flare spectrum used is representative. We also consider the effects on Sgr A*s quiescent spectrum in the case of a density increase due to the G2 encounter with Sgr A*.
SN 2010jl: Optical to hard X-ray observations reveal an explosion embedded in a ten solar mass cocoon
E. O. Ofek,A. Zoglauer,S. E. Boggs,N. M. Barriere,S. P. Reynolds,C. L. Fryer,F. A. Harrison,S. B. Cenko,S. R. Kulkarni,A. Gal-Yam,I. Arcavi,E. Bellm,J. S. Bloom,F. Christensen,W. W. Craig,W. Even,A. V. Filippenko,B. Grefenstette,C. J. Hailey,R. Laher,K. Madsen,E. Nakar,P. E. Nugent,D. Stern,M. Sullivan,J. Surace,W. W. Zhang
Physics , 2013, DOI: 10.1088/0004-637X/781/1/42
Abstract: (Abridged) Some supernovae (SNe) may be powered by the interaction of the SN ejecta with a large amount of circumstellar matter (CSM). Here we outline a method to measure the mass of the optically thick CSM around such SNe. We present observations of SN2010jl, including the first detection of a SN using NuSTAR. The total radiated luminosity of SN2010jl is extreme, at least 9e50 erg. By modeling the visible-light data, we robustly show that the mass of the circumstellar material within ~1e16 cm of the progenitor was in excess of 10 solar masses, likely ejected tens of years prior to the SN explosion. Our modeling suggests that the shock velocity during shock breakout was ~6000 km/s, decelerating to ~2600 km/s about two years after maximum light. Our late-time NuSTAR+XMM spectra of the SN presumably provide the first direct measurement of SN shock velocity two years after the SN maximum light -- measured to be in the range of 2000 to 4500 km/s if the ions and electrons are in equilibrium, and >~2000 km/s if they are not in equilibrium. This measurement is in agreement with the shock velocity predicted by our modeling of the optical data. We also show that the mean radial density distribution of the CSM roughly follows an r^-2 law. A possible explanation for the massive CSM with a wind-like profile is that they are the result of multiple pulsational pair instability events prior to the SN explosion, separated from each other by years.
Concept Clustering and Knowledge Integration from a Children's Dictionary
Caroline Barriere,Fred Popowich
Computer Science , 1997,
Abstract: Knowledge structures called Concept Clustering Knowledge Graphs (CCKGs) are introduced along with a process for their construction from a machine readable dictionary. CCKGs contain multiple concepts interrelated through multiple semantic relations together forming a semantic cluster represented by a conceptual graph. The knowledge acquisition is performed on a children's first dictionary. A collection of conceptual clusters together can form the basis of a lexical knowledge base, where each CCKG contains a limited number of highly connected words giving useful information about a particular domain or situation.
Letter of Intent for Double-CHOOZ: a Search for the Mixing Angle Theta13
F. Ardellier,I. Barabanov,J. C. Barriere,M. Bauer,L. Bezrukov,C. Buck,C. Cattadori,B. Courty,M. Cribier,F. Dalnoki-Veress,N. Danilov,H. de Kerret,A. Di Vacri,A. Etenko,M. Fallot,Ch. Grieb,M. Goeger,A. Guertin,T. Kirchner,Y. S. Krylov,D. Kryn,C. Hagner,W. Hampel,F. X. Hartmann,P. Huber,J. Jochum,T. Lachenmaier,Th. Lasserre,Ch. Lendvai,M. Lindner,F. Marie,J. Martino,G. Mention,A. Milsztajn,J. P. Meyer,D. Motta,L. Oberauer,M. Obolensky,L. Pandola,W. Potzel,S. Schoenert,U. Schwan,T. Schwetz,S. Scholl,L. Scola,M. Skorokhvatov,S. Sukhotin,A. Letourneau,D. Vignaud,F. von Feilitzsch,W. Winter,E. Yanovich
Physics , 2004,
Abstract: Tremendous progress has been achieved in neutrino oscillation physics during the last few years. However, the smallness of the $\t13$ neutrino mixing angle still remains enigmatic. The current best constraint comes from the CHOOZ reactor neutrino experiment $\s2t13 < 0.2$ (at 90% C.L., for $\adm2=2.0 10^{-3} \text{eV}^2$). We propose a new experiment on the same site, Double-CHOOZ, to explore the range of $\s2t13$ from 0.2 to 0.03, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the cosmic ray induced background. Therefore, Double-CHOOZ will use two identical detectors, one at $\sim$150 m and another at 1.05 km distance from the nuclear cores. The plan is to start data taking with two detectors in 2008, and to reach a sensitivity of 0.05 in 2009, and 0.03 in 2011.
Experimental and theoretical study of diffraction properties of various crystals for the realization of a soft gamma-ray Laue lens
Nicolas Barriere,Julien Rousselle,Peter von Ballmoos,Nikolai V. Abrosimov,Pierre Courtois,Pierre Bastie,Thierry Camus,Michael Jentschel,Vladimir N. Kurlov,Lorenzo Natalucci,Gilles Roudil,Nicolai Frisch Brejnholt,Denis Serre
Physics , 2009,
Abstract: Crystals are the elementary constituents of Laue lenses, an emerging technology which could allow the realization of a space borne telescope 10 to 100 times more sensitive than existing ones in the 100 keV - 1.5 MeV energy range. This study addresses the current endeavor to the development of efficient crystals for the realization of a Laue lens. In the theoretical part 35 candidate-crystals both pure and two-components are considered. Their peak reflectivity at 100 keV, 500 keV and 1 MeV is calculated assuming they are mosaic crystals. It results that a careful selection of crystals can allow a reflectivity above 30% over the whole energy range, and even reaching 40% in its lower part. Experimentally, we concentrated on three different materials (Si_{1-x}Ge_x with gradient of composition, mosaic Cu and Au) that have been measured both at ESRF and ILL using highly-monochromatic beams ranging from 300 keV up to 816 keV. The aim was to check their homogeneity, quality and angular spread (mosaicity). These crystals have shown outstanding performance such as reflectivity up to 31% at ~600 keV (Au) or 60% at 300 keV (SiGe) and angular spread as low as 15 arcsec for Cu, fulfilling very well the requirements for a Laue lens application. Unexpectedly, we also noticed important discrepancies with Darwin's model when a crystal is measured using various energies.
First Measurement of θ_13 from Delayed Neutron Capture on Hydrogen in the Double Chooz Experiment
Double Chooz Collaboration,Y. Abe,C. Aberle,J. C. dos Anjos,J. C. Barriere,M. Bergevin,A. Bernstein,T. J. C. Bezerra,L. Bezrukhov,E. Blucher,N. S. Bowden,C. Buck,J. Busenitz,A. Cabrera,E. Caden,L. Camilleri,R. Carr,M. Cerrada,P. -J. Chang,P. Chimenti,T. Classen,A. P. Collin,E. Conover,J. M. Conrad,J. I. Crespo-Anadón,K. Crum,A. Cucoanes,E. Damon,J. V. Dawson,S. Dazeley,D. Dietrich,Z. Djurcic,M. Dracos,V. Durand,J. Ebert,Y. Efremenko,M. Elnimr,A. Erickson,A. Etenko,M. Fallot,M. Fechner,F. von Feilitzsch,J. Felde,S. M. Fernandes,V. Fischer,D. Franco,A. J. Franke,M. Franke,H. Furuta,R. Gama,I. Gil-Botella,L. Giot,M. G?ger-Neff,L. F. G. Gonzalez,L. Goodenough,M. C. Goodman,J. TM. Goon,D. Greiner,N. Haag,S. Habib,C. Hagner,T. Hara,F. X. Hartmann,J. Haser,A. Hatzikoutelis,T. Hayakawa,M. Hofmann,G. A. Horton-Smith,A. Hourlier,M. Ishitsuka,J. Jochum,C. Jollet,C. L. Jones,F. Kaether,L. N. Kalousis,Y. Kamyshkov,D. M. Kaplan,T. Kawasaki,G. Keefer,E. Kemp,H. de Kerret,T. Konno,D. Kryn,M. Kuze,T. Lachenmaier,C. E. Lane,C. Langbrandtner,T. Lasserre,A. Letourneau,D. Lhuillier,H. P. Lima Jr,M. Lindner,J. M. López-Casta?o,J. M. LoSecco,B. K. Lubsandorzhiev,S. Lucht,D. McKee,J. Maeda,C. N. Maesano,C. Mariani,J. Maricic,J. Martino,T. Matsubara,G. Mention,A. Meregaglia,M. Meyer,T. Miletic,R. Milincic,H. Miyata,Th. A. Mueller,Y. Nagasaka,K. Nakajima,P. Novella,M. Obolensky,L. Oberauer,A. Onillon,A. Osborn,I. Ostrovskiy,C. Palomares,I. M. Pepe,S. Perasso,P. Perrin,P. Pfahler,A. Porta,W. Potzel
Statistics , 2013, DOI: 10.1016/j.physletb.2013.04.050
Abstract: The Double Chooz experiment has determined the value of the neutrino oscillation parameter $\theta_{13}$ from an analysis of inverse beta decay interactions with neutron capture on hydrogen. This analysis uses a three times larger fiducial volume than the standard Double Chooz assessment, which is restricted to a region doped with gadolinium (Gd), yielding an exposure of 113.1 GW-ton-years. The data sample used in this analysis is distinct from that of the Gd analysis, and the systematic uncertainties are also largely independent, with some exceptions, such as the reactor neutrino flux prediction. A combined rate- and energy-dependent fit finds $\sin^2 2\theta_{13}=0.097\pm 0.034(stat.) \pm 0.034 (syst.)$, excluding the no-oscillation hypothesis at 2.0 \sigma. This result is consistent with previous measurements of $\sin^2 2\theta_{13}$.
Reactor electron antineutrino disappearance in the Double Chooz experiment
Y. Abe,C. Aberle,J. C. dos Anjos,J. C. Barriere,M. Bergevin,A. Bernstein,T. J. C. Bezerra,L. Bezrukhov,E. Blucher,N. S. Bowden,C. Buck,J. Busenitz,A. Cabrera,E. Caden,L. Camilleri,R. Carr,M. Cerrada,P. -J. Chang,P. Chimenti,T. Classen,A. P. Collin,E. Conover,J. M. Conrad,J. I. Crespo-Anadón,K. Crum,A. Cucoanes,M. V. D'Agostino,E. Damon,J. V. Dawson,S. Dazeley,D. Dietrich,Z. Djurcic,M. Dracos,V. Durand,J. Ebert,Y. Efremenko,M. Elnimr,A. Etenko,M. Fallot,M. Fechner,F. von Feilitzsch,J. Felde,D. Franco,A. J. Franke,M. Franke,H. Furuta,R. Gama,I. Gil-Botella,L. Giot,M. Goger-Neff,L. F. G. Gonzalez,M. C. Goodman,J. TM. Goon,D. Greiner,N. Haag,C. Hagner,T. Hara,F. X. Hartmann,J. Haser,A. Hatzikoutelis,T. Hayakawa,M. Hofmann,G. A. Horton-Smith,A. Hourlier,M. Ishitsuka,J. Jochum,C. Jollet,C. L. Jones,F. Kaether,L. N. Kalousis,Y. Kamyshkov,D. M. Kaplan,T. Kawasaki,G. Keefer,E. Kemp,H. de Kerret,Y. Kibe,T. Konno,D. Kryn,M. Kuze,T. Lachenmaier,C. E. Lane,C. Langbrandtner,T. Lasserre,A. Letourneau,D. Lhuillier,H. P. Lima Jr,M. Lindner,J. M. López-Castan?,J. M. LoSecco,B. K. Lubsandorzhiev,S. Lucht,D. McKee,J. Maeda,C. N. Maesano,C. Mariani,J. Maricic,J. Martino,T. Matsubara,G. Mention,A. Meregaglia,T. Miletic,R. Milincic,H. Miyata,Th. A. Mueller,Y. Nagasaka,K. Nakajima,P. Novella,M. Obolensky,L. Oberauer,A. Onillon,A. Osborn,I. Ostrovskiy,C. Palomares,I. M. Pepe,S. Perasso,P. Perrin,P. Pfahler,A. Porta,W. Potzel,J. Reichenbacher,B. Reinhold,A. Remoto,M. Rohling,R. Roncin,S. Roth
Statistics , 2012, DOI: 10.1103/PhysRevD.86.052008
Abstract: The Double Chooz experiment has observed 8,249 candidate electron antineutrino events in 227.93 live days with 33.71 GW-ton-years (reactor power x detector mass x livetime) exposure using a 10.3 cubic meter fiducial volume detector located at 1050 m from the reactor cores of the Chooz nuclear power plant in France. The expectation in case of theta13 = 0 is 8,937 events. The deficit is interpreted as evidence of electron antineutrino disappearance. From a rate plus spectral shape analysis we find sin^2 2{\theta}13 = 0.109 \pm 0.030(stat) \pm 0.025(syst). The data exclude the no-oscillation hypothesis at 99.8% CL (2.9{\sigma}).
Direct Measurement of Backgrounds using Reactor-Off Data in Double Chooz
Y. Abe,C. Aberle,J. C. dos Anjos,J. C. Barriere,M. Bergevin,A. Bernstein,T. J. C. Bezerra,L. Bezrukhov,E. Blucher,N. S. Bowden,C. Buck,J. Busenitz,A. Cabrera,E. Caden,L. Camilleri,R. Carr,M. Cerrada,P. -J. Chang,P. Chimenti,T. Classen,A. P. Collin,E. Conover,J. M. Conrad,J. I. Crespo-Anadon,K. Crum,A. Cucoanes,M. V. D'Agostino,E. Damon,J. V. Dawson,S. Dazeley,D. Dietrich,Z. Djurcic,M. Dracos,V. Durand,J. Ebert,Y. Efremenko,M. Elnimr,A. Erickson,A. Etenko,M. Fallot,M. Fechner,F. von Feilitzsch,J. Felde,S. M. Fernandes,V. Fischer,D. Franco,A. J. Franke,M. Franke,H. Furuta,R. Gama,I. Gil-Botella,L. Giot,M. G?ger-Neff,L. F. G. Gonzalez,L. Goodenough,M. C. Goodman,J. TM. Goon,D. Greiner,N. Haag,S. Habib,C. Hagner,T. Hara,F. X. Hartmann,J. Haser,A. Hatzikoutelis,T. Hayakawa,M. Hofmann,G. A. Horton-Smith,A. Hourlier,M. Ishitsuka,J. Jochum,C. Jollet,C. L. Jones,F. Kaether,L. N. Kalousis,Y. Kamyshkov,D. M. Kaplan,T. Kawasaki,G. Keefer,E. Kemp,H. de Kerret,Y. Kibe,T. Konno,D. Kryn,M. Kuze,T. Lachenmaier,C. E. Lane,C. Langbrandtner,T. Lasserre,A. Letourneau,D. Lhuillier,H. P. Lima Jr,M. Lindner,J. M. Lopez-Castano,J. M. LoSecco,B. K. Lubsandorzhiev,S. Lucht,D. McKee,J. Maeda,C. N. Maesano,C. Mariani,J. Maricic,J. Martino,T. Matsubara,G. Mention,A. Meregaglia,M. Meyer,T. Miletic,R. Milincic,H. Miyata,Th. A. Mueller,Y. Nagasaka,K. Nakajima,P. Novella,M. Obolensky,L. Oberauer,A. Onillon,A. Osborn,I. Ostrovskiy,C. Palomares,I. M. Pepe,S. Perasso,P. Perrin,P. Pfahler,A. Porta,W. Potzel
Physics , 2012, DOI: 10.1103/PhysRevD.87.011102
Abstract: Double Chooz is unique among modern reactor-based neutrino experiments studying $\bar \nu_e$ disappearance in that data can be collected with all reactors off. In this paper, we present data from 7.53 days of reactor-off running. Applying the same selection criteria as used in the Double Chooz reactor-on oscillation analysis, a measured background rate of 1.0$\pm$0.4 events/day is obtained. The background model for accidentals, cosmogenic $\beta$-$n$-emitting isotopes, fast neutrons from cosmic muons, and stopped-$\mu$ decays used in the oscillation analysis is demonstrated to be correct within the uncertainties. Kinematic distributions of the events, which are dominantly cosmic-ray-produced correlated-background events, are provided. The background rates are scaled to the shielding depths of two other reactor-based oscillation experiments, Daya Bay and RENO.
Precision Muon Reconstruction in Double Chooz
Double Chooz collaboration,Y. Abe,J. C. dos Anjos,J. C. Barriere,E. Baussan,I. Bekman,M. Bergevin,T. J. C. Bezerra,L. Bezrukov,E. Blucher,C. Buck,J. Busenitz,A. Cabrera,E. Caden,L. Camilleri,R. Carr,M. Cerrada,P. -J. Chang,E. Chauveau,P. Chimenti,A. P. Collin,E. Conover,J. M. Conrad,J. I. Crespo-Anadón,K. Crum,A. Cucoanes,E. Damon,J. V. Dawson,D. Dietrich,Z. Djurcic,M. Dracos,M. Elnimr,A. Etenko,M. Fallot,F. von Feilitzsch,J. Felde,S. M. Fernandes,V. Fischer,D. Franco,M. Franke,H. Furuta,I. Gil-Botella,L. Giot,M. G?ger-Neff,L. F. G. Gonzalez,L. Goodenough,M. C. Goodman,C. Grant,N. Haag,T. Hara,J. Haser,M. Hofmann,G. A. Horton-Smith,A. Hourlier,M. Ishitsuka,J. Jochum,C. Jollet,F. Kaether,L. N. Kalousis,Y. Kamyshkov,D. M. Kaplan,T. Kawasaki,E. Kemp,H. de Kerret,D. Kryn,M. Kuze,T. Lachenmaier,C. E. Lane,T. Lasserre,A. Letourneau,D. Lhuillier,H. P. Lima Jr,M. Lindner,J. M. López-Casta no,J. M. LoSecco,B. Lubsandorzhiev,S. Lucht,J. Maeda,C. Mariani,J. Maricic,J. Martino,T. Matsubara,G. Mention,A. Meregaglia,T. Miletic,R. Milincic,A. Minotti,Y. Nagasaka,Y. Nikitenko,P. Novella,M. Obolensky,L. Oberauer,A. Onillon,A. Osborn,C. Palomares,I. M. Pepe,S. Perasso,P. Pfahler,A. Porta,G. Pronost,J. Reichenbacher,B. Reinhold,M. R?hling,R. Roncin,S. Roth,B. Rybolt,Y. Sakamoto,R. Santorelli,A. C. Schilithz,S. Sch?nert,S. Schoppmann,M. H. Shaevitz,R. Sharankova,S. Shimojima,V. Sibille,V. Sinev,M. Skorokhvatov,E. Smith,J. Spitz,A. Stahl,I. Stancu,L. F. F. Stokes,M. Strait,A. Stüken,F. Suekane
Physics , 2014, DOI: 10.1016/j.nima.2014.07.058
Abstract: We describe a muon track reconstruction algorithm for the reactor anti-neutrino experiment Double Chooz. The Double Chooz detector consists of two optically isolated volumes of liquid scintillator viewed by PMTs, and an Outer Veto above these made of crossed scintillator strips. Muons are reconstructed by their Outer Veto hit positions along with timing information from the other two detector volumes. All muons are fit under the hypothesis that they are through-going and ultrarelativistic. If the energy depositions suggest that the muon may have stopped, the reconstruction fits also for this hypothesis and chooses between the two via the relative goodness-of-fit. In the ideal case of a through-going muon intersecting the center of the detector, the resolution is ~40 mm in each transverse dimension. High quality muon reconstruction is an important tool for reducing the impact of the cosmogenic isotope background in Double Chooz.
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