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Sample records for ams-02 transition radiation

  1. Performance of the AMS-02 Transition Radiation Detector

    CERN Document Server

    Doetinchem, P; Karpinski, W; Kirn, T; Lübelsmeyer, K; Orboeck, J; Schael, S; Schultz von Dratzig, A; Schwering, G; Siedenburg, T; Siedling, R; Wallraff, W; Becker, U; Bürger, J; Henning, R; Kounine, A; Koutsenko, V F; Wyatt, J

    2006-01-01

    For cosmic particle spectroscopy on the International Space Station the AMS experiment will be equipped with a Transition Radiation Detector (TRD) to improve particle identification. The TRD has 20 layers of fleece radiator with Xe/CO2 proportional mode straw tube chambers. They are supported in a conically shaped octagon structure made of CFC-Al-honeycomb. For low power consumption VA analog multiplexers are used as front-end readout. A 20 layer prototype built from final design components has achieved proton rejections from 100 to 2000 at 90% electron efficiency for proton beam energies up to 250 GeV with cluster counting, likelihood and neural net selection algorithms.

  2. Cross-calibration of the Transition Radiation Detector of AMS-02 for an Energy Measurement of Cosmic-Ray Ions

    CERN Document Server

    Obermeier, Andreas

    2014-01-01

    Since May 2011 the AMS-02 experiment is installed on the International Space Station and is observing cosmic radiation. It consists of several state-of-the-art sub-detectors, which redundantly measure charge and energy of traversing particles. Due to the long exposure time of AMS-02 of many years the measurement of momentum for protons and ions is limited systematically by the spatial resolution and magnetic field strength of the silicon tracker. The maximum detectable rigidity for protons is about 1.8~TV, for helium about 3.6~TV. We investigate the possibility to extend the range of the energy measurement for heavy nuclei ($Z\\geq2$) with the transition radiation detector (TRD). The response function of the TRD shows a steep increase in signal from the level of ionization at a Lorentz factor $\\gamma$ of about 500 to $\\gamma\\approx20000$, where the transition radiation signal saturates. For heavy ions the signal fluctuations in the TRD are sufficiently small to allow an energy measurement with the TRD beyond t...

  3. Identification of positrons and electrons in the cosmic radiation with the electromagnetic calorimeter ECAL for the AMS-02 experiment

    CERN Document Server

    AUTHOR|(CDS)2080883

    2011-07-19

    In May 2011 AMS-02 detector has been successfully installed on the International Space Station (ISS), where it will take data on cosmic radiation from 1 to 1000 GeV for at least 10 years. Among all scientific objectives of the experiment, one of the most important is the search for Dark Matter (DM), which constitutes 80% of the Universe matter, but its nature is still unknown. A DM signal can be identified by studying the combined fluxes of positrons, photons, antiprotons and antideuterium. Thanks to its high acceptance and its performances, AMS-02 detector can extend primary cosmic ray physics search to a new energy range with high accuracy. A key role for these measurements, in particular for the electromagnetic channels, is played by ECAL calorimeter. This subdetector has been developed to measure e− and e+ energy with an accuracy of few %. Thanks to its 3D shower reconstruction imaging capabilities, it also has a high separation power between electromagnetic and hadronic showers (e/p rejection), essent...

  4. Identifying electrons and positrons with AMS-02

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Nikolas [RWTH Aachen University (Germany)

    2015-07-01

    The AMS-02 experiment is a multi-purpose detector for cosmic ray particles mounted on the International Space Station. It recorded over 40 billion events since its installation in 2011. The bulk of these events are protons, which are most abundant in cosmic rays. Electrons are 100 times and positrons 1000 times less abundant. Measuring the positrons as function of energy is especially interesting, as an excess over the expected astrophysical background may hint at an additional source of positrons in the galaxy or a new phenomena responsible for the excess, e.g. dark-matter annihilation. In order to measure positrons accurately with a small uncertainty, a large proton rejection of 10{sup 6} is needed. AMS-02 offers a transition radiation detector to separate positrons from protons and an electromagnetic calorimeter allowing a precise measurement of the kinetic energy of an incoming lepton. This talk covers the general strategy of identifying electrons/positrons with AMS-02 and presents the so-obtained electron/positron fluxes that were recently published.

  5. Towards an antiproton measurement with AMS-02

    Energy Technology Data Exchange (ETDEWEB)

    Bachlechner, Andreas [RWTH Aachen University (Germany)

    2015-07-01

    AMS-02 is a multi-purpose high-precision particle detector. It has been onboard the International Space Station since May 2011. The antiprotons measurement is an important part of the AMS-02 physics program. An excess above the expected spectrum due to interactions of cosmic rays with the interstellar matter can hint at exotic sources like dark matter annihilation. The antiproton-to-proton ratio and the antiproton flux itself may also improve the understanding of the origin and propagation of cosmic rays. Due to the very small fraction of antiprotons in the cosmic radiation of about 10{sup -5} compared to protons a very precise particle identification is needed. The main backgrounds are other singly charged particles like protons, electrons, and pions produced within the detector material itself. At lower energies the ring-imaging Cherenkov detector and the time-of-flight system help to separate light particles from protons. The electromagnetic calorimeter and the transition radiation detector redundantly suppress the electron background. The reconstruction of the charge sign by the magnetic spectrometer is limited by its resolution and has to be taken into account carefully. The strategies to identify antiprotons in the cosmic-ray measurement in different energy regions are presented. Methods to suppress and the effect of the backgrounds to the antiproton-to-proton ratio are discussed.

  6. AMS-02 fits Dark Matter

    CERN Document Server

    Balázs, Csaba

    2015-01-01

    In this work we perform a comprehensive statistical analysis of the AMS-02 electron, positron fluxes and the antiproton-to-proton ratio in the context of a simplified dark matter model. We include known, standard astrophysical sources and a dark matter component in the cosmic ray injection spectra. To predict the AMS-02 observables we use propagation parameters extracted from observed fluxes of heavier nuclei and the low energy part of the AMS-02 data. We assume that the dark matter particle is a Majorana fermion coupling to third generation fermions via a spin-0 mediator, and annihilating to multiple channels at once. The simultaneous presence of various annihilation channels provides the dark matter model with additional flexibility, and this enables us to simultaneously fit all cosmic ray spectra using a simple particle physics model and coherent astrophysical assumptions. Our results indicate that AMS-02 observations are not only consistent with the dark matter hypothesis within the uncertainties, but add...

  7. The AMS-02 electromagnetic calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Cadoux, F.; Cervelli, F.; Chambert-Hermel, V.; Chen, G.; Chen, H.; Coignet, G.; Di Falco, S.; Dubois, J.M.; Falchini, E.; Franzoso, A.; Fougeron, D.; Fouque, N.; Galeotti, S.; Girard, L.; Goy, C.; Hermel, R.; Incagli, M.; Kossakowski, R.; Lieunard, B.; Liu, Y.; Liu, Z.; Lomtadze, T.; Maestro, P.; Marrocchesi, P.S.; Paoletti, R.; Pilo, F. E-mail: federico.pilo@pi.infn.it; Rosier-Lees, S.; Spinella, F.; Turini, N.; Valle, G.; Venanzoni, G.; Vialle, J.P.; Yu, Z.; Zhuang, H

    2002-12-01

    The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a lead-scintillating fibers sampling calorimeter characterized by high granularity that allows to image the longitudinal and lateral showers development, a key issue to provide high electron/hadron discrimination. The light collection system and the FE electronics are designed to let the calorimeter operate over a wide energy range from few GeV up to 1 TeV. A full-scale prototype of the e.m. calorimeter was tested at CERN in October 2001 using electrons and pions beams with energy ranging from 3 to 100 GeV. Effective sampling thickness, linearity and energy resolution were measured.

  8. The AMS-02 electromagnetic calorimeter

    CERN Document Server

    Cadoux, F; Chambert-Hermel, V; Chen, G; Chen, H; Coignet, G; Di Falco, S; Dubois, J M; Falchini, E; Franzoso, A; Fougeron, D; Fouque, N; Galeotti, S; Girard, L; Goy, C; Hermel, R; Incagli, M; Kossakowski, R; Lieunard, B; Liu, Y; Liu, Z; Lomtadze, T A; Maestro, P; Marrocchesi, P S; Paoletti, R; Pilo, F; Rosier-Lees, S; Spinella, F; Turini, N; Valle, G D; Venanzoni, G; Vialle, J P; Yu, Z; Zhuang, H

    2002-01-01

    The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a lead-scintillating fibers sampling calorimeter characterized by high granularity that allows to image the longitudinal and lateral showers development, a key issue to provide high electron/hadron discrimination. The light collection system and the FE electronics are designed to let the calorimeter operate over a wide energy range from few GeV up to 1 TeV. A full-scale prototype of the e.m. calorimeter was tested at CERN in October 2001 using electrons and pions beams with energy ranging from 3 to 100 GeV. Effective sampling thickness, linearity and energy resolution were measured. (8 refs).

  9. Anomalous Galactic Cosmic Rays in the Framework of AMS-02

    Science.gov (United States)

    Khiali, Behrouz; Haino, Sadakazu; Feng, Jie

    2017-02-01

    The cosmic-ray (CR) energy spectra of protons and helium nuclei, which are the most abundant components of cosmic radiation, exhibit a remarkable hardening at energies above 100 GeV/nucleon. Recent data from AMS-02 confirm this feature with a higher significance. These data challenge the current models of CR acceleration in Galactic sources and propagation in the Galaxy. Here, we explain the observed break in the spectra of protons and helium nuclei in light of recent advances in CR diffusion theories in turbulent astrophysical sources as being a result of a transition between different CR diffusion regimes. We reconstruct the observed CR spectra using the fact that a transition from normal diffusion to superdiffusion changes the efficiency of particle acceleration and causes the change in the spectral index. We find that calculated proton and helium spectra match the data very well.

  10. Performances of the AMS-02 electromagnetic calorimeter

    CERN Document Server

    Cervelli, F; Lomtadze, T A; Venanzoni, G; Falchini, E; Maestro, P; Marrocchesi, P S; Paoletti, R; Pilo, F; Turini, N; Valle, G D; Coignet, G; Girard, L; Goy, C; Kossakowski, R; Lees-Rosier, S; Vialle, J P; Chen, G; Chen, H; Liu, Z; Lu, Y; Yu, Z; Zhuang, H L

    2002-01-01

    A full-scale prototype of the e.m. calorimeter for the AMS-02 experiment was tested at CERN in October 2001 using 100 GeV pion and electron beams with energy ranging from 3 to 100 GeV. The detector, a lead-scintillating fiber sampling calorimeter about 17 radiation lengths deep, is read out by an array of multianode photomultipliers. The calorimeter's high granularity allows to image the longitudinal and lateral showers development, a key issue to provide high electron /hadron discrimination. From the test beam data, linearity and energy resolution were measured as well as the effective sampling thickness. The latter was extracted from the data by fitting the longitudinal e.m. shower profiles at different energies. (9 refs).

  11. Indirect and inclusive search for dark matter with AMS02 space spectrometer; Recherche indirecte et inclusive de matiere noire avec le spectrometre spatial AMS02

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Pierre [Laboratoire d' Annecy-le-vieux de Physique des Particules, Chemin de Bellevue, BP 110, 74941 Annecy-le-Vieux Cedex (France)

    2007-07-01

    AMS02 is a particle physics detector designed for 3 years of data taking aboard the International Space Station. Equipped with a superconducting magnet, it will allow to measure gamma and cosmic ray fluxes in the GeV to TeV region with high particle identification capabilities. Its performance is based on the redundancy of measurements in specific sub-detectors: a Time-Of-Flight counter, a Transition Radiation Detector, a Silicon Tracker, a Ring Imaging Cherenkov counter and an Electromagnetic calorimeter (Ecal). The Ecal is studied in details, in particular with the qualification of a stand-alone trigger devoted to gamma ray astronomy. This system allows to increase the AMS02 sensitivity to photons, and to improve the reconstruction of electromagnetic events. The analog part of the trigger system has been tested with test benches and in-beam at CERN. The in-orbit calibration of the Ecal is studied, it may proceed in two steps. First, the Ecal cells responses have to be equalized with minimum ionizing particles data. Then an absolute calibration can be performed with cosmic electrons. For both the relative and the absolute calibration, possible procedures are defined and realistic calibration times are estimated. The second part deals with the indirect searches for dark matter and the study of the AMS02 sensitivity. Dark matter stands for 84% of the Universe mass and could consist in new particles. Dark matter particles are expected to surround our Galaxy and annihilate in high density regions. These annihilations could become observable exotic primary cosmic ray sources. Searches for anomalous excesses in (p-bar, e{sup +}, D-bar) and {gamma} ray fluxes will be performed by AMS02. A numerical tool allowing to perform predictions for these exotic fluxes within supersymmetry or extra-dimension is developed and is presented in details. Phenomenological studies regarding possible enhancements of these signals by over-dense regions of the halo have also been performed

  12. Recent results from the AMS-02 experiment

    Directory of Open Access Journals (Sweden)

    Vecchi Manuela

    2015-01-01

    Full Text Available The AMS-02 detector is a large acceptance magnetic spectrometer operating onboard the International Space Station since May 2011. The main goals of the detector are the search for antimatter and dark matter in space, as well as the measurement of cosmic ray composition and flux. Precise measurements of cosmic ray positrons and electrons are presented in this document, based on 41×109 events collected during the first 30 months of operations.

  13. Astrophysics with the AMS-02 experiment

    CERN Document Server

    Peireira, Rui

    2007-01-01

    The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV, using state-of-the-art particle identification techniques. Following the successful flight of the detector prototype (AMS-01) aboard the space shuttle, AMS-02 is expected to provide a significant improvement on the current knowledge of the elemental and isotopic composition of hadronic cosmic rays due to its long exposure time (minimum of 3 years) and large acceptance (0.5 m^2 sr) which will enable it to collect a total statistics of more than 10^10 nuclei. Detector capabilities for charge, velocity and mass identification, estimated from ion beam tests and detailed Monte Carlo simulations, are presented. Relevant issues in cosmic ray astrophysics addressed by AMS-02, including the test of cosmic ...

  14. Indirect and inclusive search for dark matter with AMS02 space spectrometer; Recherche indirecte et inclusive de matiere noire avec le spectrometre spatial AMS02

    Energy Technology Data Exchange (ETDEWEB)

    Brun, P

    2007-06-15

    AMS02 is a particle physics detector designed for 3 years of data collecting aboard the International Space Station. Equipped with a superconducting magnet, it will allow to measure gamma and cosmic ray fluxes in the GeV to TeV region with high particle identification capabilities. Its performance is based on the redundancy of measurements in specific sub-detectors: a Time-Of-Flight counter, a Transition Radiation Detector, a Silicon Tracker, a Ring Imaging Cherenkov counter and an Electromagnetic calorimeter (Ecal). The Ecal is studied in details, in particular with the qualification of a stand-alone trigger devoted to gamma ray astronomy. This system allows the increase of the AMS02 sensitivity to photons, and the improvement of the reconstruction of electromagnetic events. The analog part of the trigger system has been tested with test benches and with a beam at CERN. The in-orbit calibration of the Ecal is studied, it may proceed in two steps. First, the Ecal cells responses have to be equalized with minimum ionizing particles data. Then an absolute calibration can be performed with cosmic electrons. For both the relative and the absolute calibration, possible procedures are defined and realistic calibration times are estimated. The second part deals with the indirect searches for dark matter and the study of the AMS02 sensitivity. Dark matter stands for 84% of the Universe mass and could consist in new particles. Dark matter particles are expected to surround our Galaxy and annihilate in high density regions. These annihilations could become observable exotic primary cosmic ray sources. Searches for anomalous excesses in (p-bar, e{sup +}, D-bar) and {gamma} ray fluxes will be performed by AMS02. A numerical tool allowing us to perform predictions for these exotic fluxes within supersymmetry or extra-dimension is developed and is presented in details. Phenomenological studies regarding possible enhancements of these signals by over-dense regions of the halo

  15. AMS-02 in Space: Physics Results

    CERN Document Server

    Tomassetti, Nicola

    2015-01-01

    The Alpha Magnetic Spectrometer (AMS-02) is a particle physics experiment designed to study origin and nature of Galactic Cosmic Rays (CRs) up to TeV energies from space. With its high sensitivity, long exposure and excellent identification capabilities, AMS is conducting a unique mission of fundamental physics research in space. To date, more than 60 billion CR events have been collected by AMS. The new results on CR leptons and the analysis and light-nuclei are presented and discussed. The new leptonic data indicate the existence of new sources of high-energy CR leptons, that may arise either by dark-matter particles annihilation or by nearby astrophysical sources of $e^{\\pm}$ pairs. Future data at higher energies and forthcoming measurements on the antiproton spectrum and the boron-to-carbon ratio will be crucial in providing the discrimination among the different scenario.

  16. Analysis of charge-sign separation in AMS-02 data

    Energy Technology Data Exchange (ETDEWEB)

    Bachlechner, Andreas [RWTH Aachen University (Germany)

    2013-07-01

    The AMS-02 experiment stationed at the International Space Station is taking cosmic-ray data since May 2011. Promising observables to improve the understanding of cosmic rays, antimatter-matter asymmetry and search for dark matter include the positron fraction, the antiproton to proton ratio and anti-helium search. For these observables a proper separation of charge sign up to the high energies is of great importance. For leptons the kinetic energy is determined redundantly by two sub-detectors: The electromagnetic calorimeter with 16 radiation lengths and the powerful spectrometer consisting of a silicon strip tracker combined with a permanent magnet. On the other hand the spectrometer is the only sub-detector in AMS-02 able separate particles according to their charge sign. This separation is limited by the resolution of the spectrometer and interactions in the detector. The resulting charge confusion needs to be understood and carefully taken into account. The preliminary results of this analysis to determine charge confusion from measured data and methods to correct for this misidentification are presented. The effect of charge confusion to the positron fraction and the antiproton proton ratio is discussed.

  17. Particle identification below threshold with AMS-02 RICH detector

    CERN Document Server

    Li, Ziyuan; Giovacchini, Francesca; Hoffman, Julia; Haino, Sadakazu

    2016-01-01

    The Alpha Magnetic Spectrometer (AMS-02) was installed on the International Space Station (ISS) and it has been collecting data successfully since May 2011. The main goals of AMS-02 are the search for cosmic anti-matter, dark matter and the precise measurement of the relative abundance of elements and isotopes in galactic cosmic rays. In order to identify particle properties, AMS-02 includes several specialized sub-detectors. Among them, the AMS-02 Ring Imaging Cherenkov detector (RICH) is designed to provide a very precise measurement of the velocity and electric charge of particles. A method to reject the dominant electron background in antiproton identification using the AMS-02 RICH detector as a veto will be described. By using the collected cosmic-rays data, electron contamination can be well suppressed within 3% with $\\beta \\approx 1$, while keeping 76% efficiency for antiprotons below the threshold.

  18. AMS-02 results support the secondary origin of cosmic ray positrons.

    Science.gov (United States)

    Blum, Kfir; Katz, Boaz; Waxman, Eli

    2013-11-22

    We show that the recent AMS-02 positron fraction measurement is consistent with a secondary origin for positrons and does not require additional primary sources such as pulsars or dark matter. The measured positron fraction at high energy saturates the previously predicted upper bound for secondary production, obtained by neglecting radiative losses. This coincidence, which will be further tested by upcoming AMS-02 data at higher energy, is a compelling indication for a secondary source. Within the secondary model, the AMS-02 data imply a cosmic ray propagation time in the Galaxy of <10(6) yr and an average traversed interstellar matter density of ~1 cm(-3), comparable to the density of the Milky Way gaseous disk, at a rigidity of 300 GV.

  19. AMS02 results support the secondary origin of cosmic ray positrons

    CERN Document Server

    Blum, Kfir; Waxman, Eli

    2013-01-01

    We show that the recent AMS02 positron fraction measurement is consistent with a secondary origin for positrons, and does not require additional primary sources such as pulsars or dark matter. The measured positron fraction at high energy saturates the previously predicted upper bound for secondary production (Katz et al 2009), obtained by neglecting radiative losses. This coincidence, which will be further tested by upcoming AMS02 data at higher energy, is a compelling indication for a secondary source. Within the secondary model the AMS02 data imply a cosmic ray propagation time in the Galaxy of < Myr and an average traversed interstellar matter density of order 1/cc, comparable to the density of the Milky Way gaseous disk, at a rigidity of 300 GV.

  20. Mass of decaying wino from AMS-02 2014

    Energy Technology Data Exchange (ETDEWEB)

    Ibe, Masahiro, E-mail: ibe@icrr.u-tokyo.ac.jp [Institute for Cosmic Ray Research (ICRR), Theory Group, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Matsumoto, Shigeki [Kavli Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Shirai, Satoshi [Deutsches Elektronen-Synchrotron (DESY), 22607 Hamburg (Germany); Yanagida, Tsutomu T. [Kavli Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, Kashiwa, Chiba 277-8568 (Japan)

    2015-02-04

    We revisit the decaying wino dark matter scenario in the light of the updated positron fraction, electron and positron fluxes in cosmic ray recently reported by the AMS-02 collaboration. We show the AMS-02 results favor the mass of the wino dark matter at around a few TeV, which is consistent with the prediction on the wino mass in the pure gravity mediation model.

  1. The AMS-02 lead-scintillating fibres Electromagnetic Calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Adloff, C.; Basara, L. [LAPP, Université de Savoie, CNRS/IN2P3, Annecy-le-Vieux (France); Bigongiari, G. [Universita' degli Studi di Siena, 53100 Siena (Italy); Bosi, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, 57023 Pisa (Italy); Brun, P.; Cadoux, F. [LAPP, Université de Savoie, CNRS/IN2P3, Annecy-le-Vieux (France); Cervelli, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, 57023 Pisa (Italy); Chambert, V. [LAPP, Université de Savoie, CNRS/IN2P3, Annecy-le-Vieux (France); Chen, G.; Chen, G.M.; Chen, H.S. [Institute of High Energy Physics, CAS, Beijing 100049 (China); Coignet, G.; Cougoulat, G. [LAPP, Université de Savoie, CNRS/IN2P3, Annecy-le-Vieux (France); Di Falco, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, 57023 Pisa (Italy); Dubois, J.M.; Elles, S. [LAPP, Université de Savoie, CNRS/IN2P3, Annecy-le-Vieux (France); Falchini, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, 57023 Pisa (Italy); Fiasson, A.; Fougeron, D.; Fouque, N. [LAPP, Université de Savoie, CNRS/IN2P3, Annecy-le-Vieux (France); and others

    2013-06-21

    The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a fine grained lead-scintillating fibres sampling calorimeter that allows for a precise three-dimensional imaging of the longitudinal and lateral shower development. It provides a high (≥10{sup 6}) electron/hadron discrimination with the other AMS-02 detectors [1] and good energy resolution. The calorimeter also provides a standalone photon trigger capability to AMS-02. The mechanical assembly was realized to ensure minimum weight, still supporting the intrinsically heavy calorimeter during launch. ECAL light collection system and electronics are designed to measure electromagnetic particles over a wide energy range, from GeV up to TeV. A full-scale flight-like model was tested using electrons and proton beams with energies ranging from 6 to 250 GeV.

  2. The AMS-02 lead-scintillating fibres Electromagnetic Calorimeter

    Science.gov (United States)

    Adloff, C.; Basara, L.; Bigongiari, G.; Bosi, F.; Brun, P.; Cadoux, F.; Cervelli, F.; Chambert, V.; Chen, G.; Chen, G. M.; Chen, H. S.; Coignet, G.; Cougoulat, G.; Di Falco, S.; Dubois, J. M.; Elles, S.; Falchini, E.; Fiasson, A.; Fougeron, D.; Fouque, N.; Galeotti, S.; Gallucci, G.; Gherarducci, F.; Girard, L.; Giuseppe, F.; Goy, C.; Hermel, R.; Incagli, M.; Jacquemier, J.; Journet, L.; Kossakowski, R.; Lepareur, V.; Li, Z. H.; Lieunard, B.; Lomtadze, T.; Lu, Y. S.; Maestro, P.; Magazzù, C.; Maire, M.; Orsini, A.; Paniccia, M.; Pedreschi, E.; Peltier, F.; Piendibene, M.; Pilo, F.; Pochon, J.; Rambure, T.; Rosier-Lees, S.; Spinella, F.; Tang, X. W.; Tassan-Viol, J.; Tazzioli, A.; Vannini, C.; Vialle, J. P.; Zhuang, H. L.

    2013-06-01

    The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a fine grained lead-scintillating fibres sampling calorimeter that allows for a precise three-dimensional imaging of the longitudinal and lateral shower development. It provides a high (≥106) electron/hadron discrimination with the other AMS-02 detectors [1] and good energy resolution. The calorimeter also provides a standalone photon trigger capability to AMS-02. The mechanical assembly was realized to ensure minimum weight, still supporting the intrinsically heavy calorimeter during launch. ECAL light collection system and electronics are designed to measure electromagnetic particles over a wide energy range, from GeV up to TeV. A full-scale flight-like model was tested using electrons and proton beams with energies ranging from 6 to 250 GeV.

  3. The RICH detector of the AMS-02 experiment: status and physics prospects

    CERN Document Server

    Pereira, Rui; Arruda, L; Barão, F; Baret, B; Barrau, A; Barreira, G; Belmont, E; Berdugo, J; Borges, J; Buénerd, M; Casadei, D; Casaus, J; Cortina, E; Costado, M; Crespo, D; Delgado, C; Díaz, C; Derome, L; Gonçalves, P; Garcia-Lopez, R; de la Guia, C; Herrero, A; Lanciotti, E; Laurenti, G; Malinin, A; Maña, C; Marin, J; Mangin-Brinet, M; Martínez, G; Menchaca-Rocha, A; Palomares, C; Pimenta, M; Putze, A; Sallaz-Damaz, Y; Seo, E S; Sevilla, I; Torrento, A; Vargas-Trevino, M; Veziant, O

    2008-01-01

    The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV. It is equipped with several subsystems, one of which is a proximity focusing RICH detector with a dual radiator (aerogel+NaF) that provides reliable measurements for particle velocity and charge. The assembly and testing of the AMS RICH is currently being finished and the full AMS detector is expected to be ready by the end of 2008. The RICH detector of AMS-02 is presented. Physics prospects are briefly discussed.

  4. AMS-02 in space: physics results, overview, and challenges

    CERN Document Server

    Tomassetti, Nicola

    2015-01-01

    The Alpha Magnetic Spectrometer (AMS-02) is a state of the art particle detector measuring cosmic rays (CRs) on the International Space Station (ISS) since May 19th 2011. AMS-02 identifies CR leptons and nuclei in the energy range from hundreds MeV to few TeV per nucleon. Several sub-detector systems allow for redundant particle identification with unprecedented precision, a powerful lepton-hadron separation, and a high purity of the antimatter signal. The new AMS-02 leptonic data from 1 to 500 GeV are presented and discussed. These new data indicate that new sources of CR leptons need to be included to describe the observed spectra at high energies. Explanations of this anomaly may be found either in dark-matter particles annihilation or in the existence of nearby astrophysical sources of $e^{\\pm}$. Future data at higher energies and forthcoming measurements on the antiproton spectrum and the boron-to-carbon ratio will be crucial in providing the discrimination among the different scenario.

  5. Imprint of Multi-component Dark Matter on AMS-02

    CERN Document Server

    Geng, Chao-Qiang; Tsai, Lu-Hsing

    2013-01-01

    The multi-component decaying dark matter (DM) scenario is investigated to explain the possible excesses in the positron fraction by PAMELA and recently confirmed by AMS-02, and in the total $e^+ +e^-$ flux observed by Fermi-LAT. By performing the $\\chi^2$ fits, we find that two DM components are already enough to give a reasonable fit of both AMS-02 and Fermi-LAT data. The best-fitted results show that the heavier DM component with its mass 1.5 TeV dominantly decays through the $\\mu$-channel, while the lighter one of 100 GeV mainly through the $\\tau$-channel. As a byproduct, the fine structure around 100 GeV observed by AMS-02 and Fermi-LAT can be naturally explained by the dropping due to the lighter DM component. With the obtained model parameters by the fitting, we calculate the diffuse $\\gamma$-ray emission spectrum in this two-component DM scenario, and find that it is consistent with the data measured by Fermi-LAT. We also construct a microscopic particle DM model to naturally realize the two-component ...

  6. Identification of Light Cosmic-Ray Nuclei with AMS-02

    CERN Document Server

    Tomassetti, Nicola

    2015-01-01

    AMS-02 is a wide acceptance (0.5 m2 sr) and long duration (up to 20 years) magnetic spectrometer operating onboard the International Space Station since May 2011. Its main scientific objectives are the indirect research of Dark Matter, searches of primitive Anti-Matter and the precise measurement of the Cosmic-Ray (CR) spectra. Among charged CR species, AMS-02 will be able to measure relative abundances and absolute fluxes of CRs nuclei from Hydrogen up to at least Iron (Z = 26) in a kinetic energy range from hundreds MeV to TeV per nucleon. The high statistics measurement of the chemical composition of CRs in this extended energy range will reveal new insights about the CRs life in the Galaxy, from their origin to the propagation in the interstellar medium, giving new constraints to astrophysical models of Galactic CRs. The nucleus absolute charge, Z, is measured several times along the trajectory of the particle inside AMS-02 using different detection techniques: in the 9 planes of the Silicon Tracker, in t...

  7. AMS-02 antiprotons from annihilating or decaying dark matter

    Directory of Open Access Journals (Sweden)

    Koichi Hamaguchi

    2015-07-01

    Full Text Available Recently the AMS-02 experiment reported an excess of cosmic ray antiprotons over the expected astrophysical background. We interpret the excess as a signal from annihilating or decaying dark matter and find that the observed spectrum is well fitted by adding contributions from the annihilation or decay of dark matter with mass of O(TeV or larger. Interestingly, Wino dark matter with mass of around 3 TeV, whose thermal relic abundance is consistent with present dark matter abundance, can explain the antiproton excess. We also discuss the implications for the decaying gravitino dark matter with R-parity violation.

  8. The electromagnetic calorimeter of the AMS-02 experiment

    Science.gov (United States)

    Vecchi, M.; Basara, L.; Bigongiari, G.; Cervelli, F.; Chen, G.; Chen, G. M.; Chen, H. S.; Coignet, G.; Di Falco, S.; Elles, S.; Fiasson, A.; Fougeron, D.; Gallucci, G.; Goy, C.; Incagli, M.; Kossakowski, R.; Lepareur, V.; Li, Z. H.; Maire, M.; Paniccia, M.; Pilo, F.; Rosier-Lees, S.; Tang, X. W.; Vannini, C.; Vialle, J. P.; Zhuang, H. L.

    2012-12-01

    The electromagnetic calorimeter (ECAL) of the AMS-02 experiment is a 3-dimensional sampling calorimeter, made of lead and scintillating fibers. The detector allows for a high granularity, with 18 samplings in the longitudinal direction, and 72 sampling in the lateral direction. The ECAL primary goal is to measure the energy of cosmic rays up to few TeV, however, thanks to the fine grained structure, it can also provide the separation of positrons from protons, in the GeV to TeV region. A direct measurement of high energy photons with accurate energy and direction determination can also be provided.

  9. AMS-02海量数据处理环境的研究%Study on AMS-02 Massive Data Processing Environment

    Institute of Scientific and Technical Information of China (English)

    杨鹏

    2011-01-01

    AMS实验是近年来具有重要影响的大型国际合作太空物理实验,AMS-02探测器即将在2011年初发射升空.AMS-02实验将产生总量超过1PB的海量数据,这些数据不但类型多样,而且处理过程非常复杂.首先介绍了AMS-02海量数据处理环境的功能需求和主要构成部件,然后分析了AMS-02海量数据的主要类型及其处理流程,最后以AMS-02 SOC为重点,详细描述了AMS-02 SOC的分布式架构、主要功能以及基于网格的AMS-02 SOC@SEU 系统实现框架等,从而为AMS-02海量数据处理环境的研究和建设提供了有益的参考.%AMS (Alpha Magnetic Spectrometer) is an international coorperative physics experiment with great influence and significance,and the AMS-02 tracker will be launched at the beginning of 2011. AMS-02 experiment will produce more than 1PB of massive data that have different types and their handling processes are very complex. This paper firstly introduced the functional requirements and the key components of the massive data processing environment of AMS-02 experiment, and then analyzed the fundamental data types and the handling processes of AMS-02 massive data, finally,paid more attention to AMS-02 SOC, the distributed architecture and the principal function of AMS-02 SOC were discussed, and a Grid-based implementation framework of AMS-02 SOC@SEU was also dicsribed.

  10. Dark Matter search with the AMS-02 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Cardano, Francesco Maria [University of Perugia, Via Pascoli n. 1, Perugia (Italy)], E-mail: cardano@fisica.unipg.it

    2008-04-01

    Late astrophysical and cosmological measurements have shown how {approx}83% of matter of the Universe is dark and non-baryonic. Supersymmetric extensions of the Standard Model can provide a good candidate as main component of Dark Matter in the neutralino {chi}. In this framework, the magnetic spectrometer AMS-02 has been conceived for the precision measurement on board of the ISS of composition and energy spectrum of cosmic rays over a wide energy range, providing the potential to detect contribution to charged particle fluxes from neutralino annihilation. Due to the general faintness of expected Dark Matter contributions to cosmic ray spectra, interesting research channels are those for which the standard astrophysical background is expected to be low, like antimatter ones. Results of various MC analysis of AMS potential in the measurement of positron, antiproton and antideuteron fluxes are presented.

  11. Dark matter for excess of AMS-02 positrons and antiprotons

    Directory of Open Access Journals (Sweden)

    Chuan-Hung Chen

    2015-07-01

    Full Text Available We propose a dark matter explanation to simultaneously account for the excess of antiproton-to-proton and positron power spectra observed in the AMS-02 experiment while having the right dark matter relic abundance and satisfying the current direct search bounds. We extend the Higgs triplet model with a hidden gauge symmetry of SU(2X that is broken to Z3 by a quadruplet scalar field, rendering the associated gauge bosons stable weakly-interacting massive particle dark matter candidates. By coupling the complex Higgs triplet and the SU(2X quadruplet, the dark matter candidates can annihilate into triplet Higgs bosons each of which in turn decays into lepton or gauge boson final states. Such a mechanism gives rise to correct excess of positrons and antiprotons with an appropriate choice of the triplet vacuum expectation value. Besides, the model provides a link between neutrino mass and dark matter phenomenology.

  12. AMS-02, Strongly Self-Interacting Dark Matter, and QUD

    CERN Document Server

    White, Alan R

    2014-01-01

    The latest AMS-02 electron/positron precision data add to the spectrum knee as direct cosmic ray evidence for an electroweak scale strong interaction. In addition, there is significant evidence for a strong self-interaction of dark matter. QUD is a unique massless SU(5) field theory with an anomaly-generated bound-state S-Matrix that could be an unconventional origin for the Standard Model. The electroweak scale color sextet quark enhanced QCD interaction is the only new physics. Production of multiple vector bosons, that acquire masses via sextet quark pions, will give the AMS positron and electron cross-sections - related vector boson pair production having been seen at the LHC. Stable sextet quark neutrons (neusons) provide a novel form of very strongly interacting dark matter that has the desired experimental properties. Large rapidity hadronic production of neusons will produce the knee.

  13. Particle identification with the AMS-02 RICH detector: search for dark matter with antideuterons

    CERN Document Server

    Arruda, Luísa; Pereira, Rui

    2007-01-01

    The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV, using state-of-the art particle identification techniques. It is equipped with several subsystems, one of which is a proximity focusing Ring Imaging Cherenkov (RICH) detector equipped with a dual radiator (aerogel+NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers and light guides, enabling precise measurements of particle electric charge and velocity (Delta beta / beta ~ 10^-3 and 10^-4 for Z=1 and Z=10-20, respectively) at kinetic energies of a few GeV/nucleon. Combining velocity measurements with data on particle rigidity from the AMS-02 Tracker (Delta R / R ~ 2% for R=1-10 GV) it is possible to obtain a reliable measurement for particle mass. One of the main topi...

  14. Solar Modulation of the Local Interstellar Spectrum with Voyager 1, AMS-02, PAMELA, and BESS

    Science.gov (United States)

    Corti, C.; Bindi, V.; Consolandi, C.; Whitman, K.

    2016-09-01

    In recent years, the increasing precision of direct cosmic rays measurements opened the door to high-sensitivity indirect searches of dark matter and to more accurate predictions for radiation doses received by astronauts and electronics in space. The key ingredients in the study of these phenomena are the knowledge of the local interstellar spectrum (LIS) of galactic cosmic rays and the understanding of how the solar modulation affects the LIS inside the heliosphere. Voyager 1, AMS-02, PAMELA, and BESS measurements of proton and helium fluxes provide valuable information, allowing us to shed light on the shape of the LIS and the details of the solar modulation during solar cycles 22-24. A new parametrization of the LIS is presented, based on the latest data from Voyager 1 and AMS-02. Using the framework of the force-field approximation, the solar modulation parameter is extracted from the time-dependent fluxes measured by PAMELA and BESS. A modified version of the force-field approximation with a rigidity-dependent modulation parameter is introduced, yielding better fits than the force-field approximation. The results are compared with the modulation parameter inferred by neutron monitors.

  15. Transition radiation by neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Ioannisian, A.N., E-mail: ara.ioannisyan@cern.ch [Yerevan Physics Institute, Alikhanian Br. 2, 375036 Yerevan (Armenia); CERN, Theory Division, CH-1211 Geneva 23 (Switzerland); Institute for Theoretical Physics and Modeling, 375036 Yerevan (Armenia); Ioannisian, D.A. [Yerevan Physics Institute, Alikhanian Br. 2, 375036 Yerevan (Armenia); Institute for Theoretical Physics and Modeling, 375036 Yerevan (Armenia); Physics Department, Yerevan State University, 1 Alex Manoogian (Armenia); Kazarian, N.A. [Institute for Theoretical Physics and Modeling, 375036 Yerevan (Armenia)

    2011-08-19

    We calculate the transition radiation process {nu}{yields}{nu}{gamma} at an interface of two media. The neutrinos are taken to be with only standard-model couplings. The medium fulfills the dual purpose of inducing an effective neutrino-photon vertex and of modifying the photon dispersion relation. The transition radiation occurs when at least one of those quantities have different values in different media. The neutrino mass is ignored due to its negligible contribution. We present a result for the probability of the transition radiation which is both accurate and analytic. For E{sub {nu}=}1 MeV neutrino crossing polyethylene-vacuum interface the transition radiation probability is about 10{sup -39} and the energy intensity is about 10{sup -34} eV. At the surface of the neutron stars the transition radiation probability may be {approx}10{sup -20}. Our result is by the three orders of magnitude larger than those of previous calculations.

  16. Transition radiation by neutrinos

    Science.gov (United States)

    Ioannisian, A. N.; Ioannisian, D. A.; Kazarian, N. A.

    2011-08-01

    We calculate the transition radiation process ν→νγ at an interface of two media. The neutrinos are taken to be with only standard-model couplings. The medium fulfills the dual purpose of inducing an effective neutrino-photon vertex and of modifying the photon dispersion relation. The transition radiation occurs when at least one of those quantities have different values in different media. The neutrino mass is ignored due to its negligible contribution. We present a result for the probability of the transition radiation which is both accurate and analytic. For Eν=1 MeV neutrino crossing polyethylene-vacuum interface the transition radiation probability is about 10 and the energy intensity is about 10 eV. At the surface of the neutron stars the transition radiation probability may be ˜10. Our result is by the three orders of magnitude larger than those of previous calculations.

  17. Decaying WIMP dark matter for AMS-02 cosmic positron excess

    CERN Document Server

    Choi, Ki-Young; Shin, Chang Sub

    2013-01-01

    For explaining the AMS-02 cosmic positron excess, which was recently reported, we consider a scenario of thermally produced and decaying dark matter (DM) into the standard model (SM) leptons with an extremely small decay rate, \\Gamma_{DM} \\sim 10^{-26} sec.^{-1}. Since the needed DM mass is relatively heavy (700 GeV < m_{DM} < 3000 GeV), we introduce another DM component apart from the lightest supersymmetric particle ("LSP"). For its (meta-) stability and annihilation into other particles, the new DM should be accompanied with another Z_2 symmetry apart from the R-parity. Sizable renormalizable couplings of the new DM with SM particles, which are necessary for its thermalization in the early universe, cannot destabilize the new DM because of the new Z_2 symmetry. Since the new DM was thermally produced, it can naturally explain the present energy density of the universe. The new DM can decay into the SM leptons (and the LSP) only through non-renormalizable operators suppressed by a superheavy squared m...

  18. Stimulated coherent transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hung-chi Lihn

    1996-03-01

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed.

  19. Alpha Magnetic Spectrometer (AMS02) experiment on the International Space Station (ISS)

    Institute of Scientific and Technical Information of China (English)

    Behcet ALPAT

    2003-01-01

    The Alpha Magnetic Spectrometer experiment is realized in two phases. A precursor flight (STS-91)with a reduced experimental configuration (AMS01) has successfully flown on space shuttle Discovery in June 1998.The final version (AMS02) will be installed on the International Space Station (ISS) as an independent module inearly 2006 for an operational period of three years. The main scientific objectives of AMS02 include the searches forthe antimatter and dark matter in cosmic rays. In this work we will discuss the experimental details as well as the im-proved physics capabilities of AMS02 on ISS.

  20. Transition Radiation Detectors

    CERN Document Server

    Andronic, A

    2012-01-01

    We review the basic features of transition radiation and how they are used for the design of modern Transition Radiation Detectors (TRD). The discussion will include the various realizations of radiators as well as a discussion of the detection media and aspects of detector construction. With regard to particle identification we assess the different methods for efficient discrimination of different particles and outline the methods for the quantification of this property. Since a number of comprehensive reviews already exist, we predominantly focus on the detectors currently operated at the LHC. To a lesser extent we also cover some other TRDs, which are planned or are currently being operated in balloon or space-borne astro-particle physics experiments.

  1. Operation of the Electronics for the AMS-02RICH Detector Prototype

    Energy Technology Data Exchange (ETDEWEB)

    Aguayo, P.; Aguilar, M.; Berdugo, J.; Casaus, J.; Delgado, C.; Diaz, C.; Fernandez, C.; Garcia-Tabares, L.; Lanciotti, E.; Mana, C.; Marin, J.; Martinez, G.; Palomares, C.; Sanchez, E.; Sevilla, I.; Torrento, A.; Wilmott, C.; Yanez, J.

    2002-07-01

    The operation and behaviour of the RICH prototype electronics developed for the AMS-02 experiment is presented. It includes results and conclusions obtained from experimental tests data with cosmic rays. (Author)

  2. Operation of the Electronics for the AMS-02 RICH Detector Prototype

    CERN Document Server

    Aguayo, P; Berdugo, J; Casaus, J; Delgado, C; Díaz, C; Fernández, C; Garcia-Tabares, L; Lanciotti, E; Marin, J; Martínez, G; Maña, C; Palomares, C; Sevilla, I; Sánchez, E; Torrento, A S; Wilmott, C; Yanez, J

    2002-01-01

    The operation and behaviour of the RICH prototype electronics developed for the AMS-02 experiment is presented. It includes results and conclusions obtained from experimental tests data with cosmic rays. (Author)

  3. ATLAS Transition Radiation Tracker

    CERN Multimedia

    2006-01-01

    The ATLAS transition radiation tracker is made of 300'000 straw tubes, up to 144cm long. Filled with a gas mixture and threaded with a wire, each straw is a complete mini-detector in its own right. An electric field is applied between the wire and the outside wall of the straw. As particles pass through, they collide with atoms in the gas, knocking out electrons. The avalanche of electrons is detected as an electrical signal on the wire in the centre. The tracker plays two important roles. Firstly, it makes more position measurements, giving more dots for the computers to join up to recreate the particle tracks. Also, together with the ATLAS calorimeters, it distinguishes between different types of particles depending on whether they emit radiation as they make the transition from the surrounding foil into the straws.

  4. ATLAS Transitional Radiation Tracker

    CERN Multimedia

    ATLAS Outreach

    2006-01-01

    This colorful 3D animation is an excerpt from the film "ATLAS-Episode II, The Particles Strike Back." Shot with a bug's eye view of the inside of the detector. The viewer is taken on a tour of the inner workings of the transitional radiation tracker within the ATLAS detector. Subjects covered include what the tracker is used to measure, its structure, what happens when particles pass through the tracker, how it distinguishes between different types of particles within it.

  5. Fermi-LAT kills dark matter interpretations of AMS-02 data. Or not?

    Science.gov (United States)

    Belotsky, Konstantin; Budaev, Ruslan; Kirillov, Alexander; Laletin, Maxim

    2017-01-01

    A number of papers attempt to explain the positron anomaly in cosmic rays, observed by PAMELA and AMS-02, in terms of dark matter (DM) decays or annihilations. However, the recent progress in cosmic gamma-ray studies challenges these attempts. Indeed, as we show, any rational DM model explaining the positron anomaly abundantly produces final state radiation and Inverse Compton gamma rays, which inevitably leads to a contradiction with Fermi-LAT isotropic diffuse gamma-ray background measurements. Furthermore, the Fermi-LAT observation of Milky Way dwarf satellites, supposed to be rich in DM, revealed no significant signal in gamma rays. We propose a generic approach in which the major contribution to cosmic rays comes from the dark matter disc and prove that the tension between the DM origin of the positron anomaly and the cosmic gamma-ray observations can be relieved. We consider both a simple model, in which DM decay/annihilate into charged leptons, and a model-independent minimal case of particle production, and we estimate the optimal thickness of DM disk. Possible mechanisms of formation and its properties are briefly discussed.

  6. Fermi-LAT kills dark matter interpretations of AMS-02 data. Or not?

    CERN Document Server

    Belotsky, Konstantin; Kirillov, Alexander; Laletin, Maxim

    2016-01-01

    A number of papers attempt to explain the positron anomaly in cosmic rays, observed by PAMELA and AMS-02, in terms of dark matter (DM) decays or annihilations. However, the recent progress in cosmic gamma-ray studies challenges these attempts. Indeed, as we show, any rational DM model explaining the positron anomaly abundantly produces final state radiation and Inverse Compton gamma rays, which inevitably leads to a contradiction with Fermi-LAT isotropic diffuse gamma-ray background measurements. Furthermore, the Fermi-LAT observation of Milky Way dwarf satellites, supposed to be rich in DM, revealed no significant signal in gamma rays. We propose a generic approach in which the major contribution to cosmic rays comes from the dark matter disc and prove that the tension between the DM origin of the positron anomaly and the cosmic gamma-ray observations can be relieved. We consider both a simple model, in which DM decay/annihilate into charged leptons, and a model-independent minimal case of particle productio...

  7. AMS-02 Capabilities in Solar Energetic Particle Measurements for Space Weather Physics

    Science.gov (United States)

    Consolandi, Cristina; Bindi, Veronica; Corti, Claudio; Hoffman, Julia; Whitman, Kathryn

    2016-04-01

    The Alpha Magnetic Spectrometer (AMS-02), thanks to its large acceptance of about 0.45 m2 sr, is the biggest Solar Energetic Particle (SEP) detector ever flown in space. AMS-02 was installed on the International Space Station (ISS) on May 19, 2011, where it will measure cosmic rays from 1 GV up to a few TV, for the duration of the ISS, currently extended till 2024. During these years of operation, AMS-02 measured several increases of the protons flux over the Galactic Cosmic Ray (GCR) background associated to the strongest solar events. AMS-02 has observed the related SEP accelerated during M- and X-class flares and fast coronal mass ejections measuring an increase of the proton flux near 1 GV and above. Some of these solar events were also followed by the typical GCR suppression i.e. Forbush decrease, which makes even more evident the measurement of the SEP flux over the GCR background. Thanks to its large acceptance and particle detection capabilities, AMS-02 is able to perform precise measurements in a short period of time which is typical of these transient phenomena and to collect enough statistics to measure fine structures and time evolution of particle spectra. The events observed by AMS-02 since the beginning of its mission will be presented and some of the more interesting events will be shown. AMS-02 observations with their unprecedented resolution and high statistics, will improve the understanding of SEP behavior at high energies to constrain models of SEP production used in space weather physics.

  8. ALICE Transition Radiation Detector

    CERN Multimedia

    Pachmayer, Y

    2013-01-01

    The Transition Radiation Detector (TRD) is the main electron detector in ALICE. In conduction with the TPC and the ITS, it provides the necessary electron identification capability to study: - Production of light and heavy vector mesons as well as the continuum in the di-electron channel, - Semi leptonic decays of hadrons with open charm and open beauty via the single-electron channel using the displaced vertex information provided by the ITS, - Correlated DD and BB pairs via coincidences of electrons in the central barrel and muons in the forward muon arm, - Jets with high Pτ tracks in one single TRD stack.

  9. AMS-02 data confront acceleration of cosmic ray secondaries in nearby sources

    DEFF Research Database (Denmark)

    Mertsch, Philipp; Sarkar, Subir

    2014-01-01

    We revisit the model proposed earlier to account for the observed increase in the positron fraction in cosmic rays with increasing energy, in the light of new data from the Alpha Magnetic Spectrometer (AMS-02) experiment. The model accounts for the production and acceleration of secondary electrons...... and positrons in nearby supernova remnants which results in an additional, harder component that becomes dominant at high energies. By fitting this to AMS-02 data we can calculate the expected concomitant rise of the boron-to-carbon ratio, as well as of the fraction of antiprotons. If these predictions...... are confirmed by the forthcoming AMS-02 data it would conclusively rule out all other proposed explanations, in particular, dark matter annihilations or decays....

  10. Constraints on cosmic ray electrons and diffuse gamma rays with AMS-02 and HESS data

    CERN Document Server

    Chen, Ding; Jin, Hong-Bo

    2014-01-01

    Lately, AMS-02 and HAWC have reported their observations of cosmic rays(CRs), which promote the further exploration of CR origins. We choose some experimental data of CRs to focus the origins of CR electrons and estimate the spectrum of CR electrons. Based on the conventional diffusion model of CRs, we perform a global analysis on the spectrum feature of CR electrons with the data of AMS-02, HESS and Milagro. The results verify that the spectrum of CR electrons has the apparent structure beyond a simple power law. The difference between the power indices above and below the reference rigidity is greater than 0.2, which is near the momentum loss rate of CR electrons. The data of HESS electrons matches the TeV extension of AMS-02 electrons and the relevant spectrum of CR electrons does not have TeV breaks. By use of the difference between the CR electrons and primary electrons constrained by AMS-02 and HESS, the TeV bounds of positron excess are predicted. In the bounds, the flux relevant to the up-limit is bey...

  11. AMS-02 data confront acceleration of cosmic ray secondaries in nearby sources

    DEFF Research Database (Denmark)

    Mertsch, Philipp; Sarkar, Subir

    2014-01-01

    We revisit the model proposed earlier to account for the observed increase in the positron fraction in cosmic rays with increasing energy, in the light of new data from the Alpha Magnetic Spectrometer (AMS-02) experiment. The model accounts for the production and acceleration of secondary electrons...

  12. A reduced scale EM Calorimeter prototype for the AMS-02 experiment

    CERN Document Server

    Cervelli, F; Coignet, G; Di Falco, S; Falchini, E; Lorntadze, T; Liu, Z; Maestro, P; Marrocchesi, P S; Paoletti, R; Pilo, F; Turini, N; Valle, G D; Vannini, C; Venanzoni, G; Yu, Z

    2002-01-01

    A reduced scale prototype of the Pb-SciFi sampling EM calorimeter for the AMS-02 experiment was tested at CERN SPS beam line X5 at energies from 5 to 250 GeV. The detector was equalized with minimum ionizing particles and calibrated with electron beams. The effective sampling thickness, linearity and energy resolution were measured. (7 refs).

  13. Operation characteristics of AMS-02 loop heat pipe with bypass valve

    CERN Document Server

    Wang, N H; Xin, G M; Song, J W; Cui, Z; Burger, J; Du, W J; Luo, F; Cheng, L

    2011-01-01

    Loop heat pipes (LHPs) were designed for the alpha magnetic spectrometer (AMS-02) to dissipate heat from the cryocoolers. A bypass valve is applied to the LHP to keep the cryocooler temperature above its limit (-20A degrees C) in cold environment. Extensive experiments were performed on operation characteristics of LHPs with the bypass valve for AMS-02 during thermal vacuum and thermal balance (TVTB) test. We found that the bypass valve can start up successfully in cold environment. With the bypass valve, the evaporator temperature is stable and can meet the requirement of the cryocooler. We analyzed three operating modes of the bypass valve. Set point temperature and regulation temperature shifts were observed and their relations with the bypass valve temperature were given.

  14. Precision measurements of nuclear CR energy spectra and composition with the AMS-02 experiment

    Science.gov (United States)

    Fiandrini, E.

    2016-05-01

    The Alpha Magnetic Spectrometer 02 (AMS-02) is a large acceptance high-energy physics experiment operating since May 2011 on board the International Space Station. More than 60 billion events have been collected by the instrument in the first four years of operation. AMS-02 offers a unique opportunity to study the Cosmic Rays (CRs) since it measures the spectra of all the species simultaneously. We report on the precision measurements of primary and secondary nuclear spectra, in the GeV-TeV energy interval. These measurements allow for the first time a detailed study of the spectral index variation with rigidity providing a new insight on the origin and propagation of CR.

  15. Indirect Dark Matter searches in the light of the recent AMS-02 observations

    CERN Document Server

    Salati, Pierre

    2016-01-01

    If the astronomical dark matter is made of weakly interacting, massive and stable species, it should annihilate on itself into particles. This process should produce rare antimatter cosmic rays and lead to distortions in their energy distributions. The AMS-02 spectrometer has been measuring them with unprecedented accuracy. It is timely to investigate if anomalies have been found in the positron and antiproton spectra and if so, if they indirectly point toward the presence of DM particles annihilating inside the Milky Way.

  16. Precise measurement of cosmic ray fluxes with the AMS-02 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vecchi, Manuela, E-mail: manuela.vecchi@ifsc.usp.br [Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970, São Carlos, SP (Brazil)

    2015-12-17

    The AMS-02 detector is a large acceptance magnetic spectrometer operating onboard the International Space Station since May 2011. The main goals of the detector are the search for antimatter and dark matter in space, as well as the measurement of cosmic ray composition and flux. In this document we present precise measurements of cosmic ray positrons, electrons and protons, collected during the first 30 months of operations.

  17. Limits on the Dark Matter from AMS-02 antiproton and positron fraction data

    CERN Document Server

    Lu, Bo-Qiang; Zong, Hong-Shi

    2015-01-01

    We derive limits on the dark matter annihilation cross section and lifetime using measurements of the AMS-02 antiproton ratio and positron fraction data. In deriving the limits, we consider the scenario of secondary particles accelerated in supernova remnants (SNRs) which has been argued to be able to reasonably account for the AMS-02 high energy positron/antiproton fraction data. We parameterize the contribution of secondary particles accelerated in SNRs and then fit the observational data within the conventional cosmic ray propagation model by adopting the GALPROP code. We use the likelihood ratio test to determine the 95$\\%$ confidence level upper limits of the possible dark matter (DM) contribution to the antiproton/positron fractions measured by AMS-02. Our limits are stronger than that set by the Fermi-LAT gamma-ray Pass 8 data of the dwarf spheroidal satellite galaxies. We also show that the solar modulation (cosmic ray propagation) parameters can play a non-negligible role in modifying the constraints...

  18. Revisiting Multi-Component Dark Matter with New AMS-02 Data

    CERN Document Server

    Geng, Chao-Qiang; Lai, Chang

    2014-01-01

    We revisit the multi-component leptonically decaying dark matter (DM) scenario to explain the possible electron/positron excesses with the recently updated AMS-02 data. We find that both the single- and two-component DM models can fit the positron fraction and $e^+/e^-$ respective fluxes, in which the two-component ones provide better fits. However, for the single-component models, the recent AMS-02 data on the positron fraction limit the DM cutoff to be smaller than 1 TeV, which conflicts with the high-energy behavior of the AMS-02 total $e^++e^-$ flux spectrum, while the two-component DM models do not possess such a problem. We also discuss the constraints from the Fermi-LAT measurement of the diffuse $\\gamma$-ray spectrum. We show that the two-component DM models are consistent with the current DM lifetime bounds. In contrast, the best-fit DM lifetimes in the single-component models are actually excluded.

  19. Probing the Pulsar Origin of the Anomalous Positron Fraction with AMS-02 and Atmospheric Cherenkov Telescopes

    CERN Document Server

    Linden, Tim

    2013-01-01

    Recent observations by PAMELA, Fermi-LAT, and AMS-02 have conclusively indicated a rise in the cosmic-ray positron fraction above 10 GeV, a feature which is impossible to mimic under the paradigm of secondary positron production with self-consistent Galactic cosmic-ray propagation models. A leading explanation for the rising positron fraction is an additional source of electron-positron pairs, for example one or more mature, energetic, and relatively nearby pulsars. We point out that any one of two well-known nearby pulsars, Geminga and Monogem, can satisfactorily provide enough positrons to reproduce AMS-02 observations. A smoking-gun signature of this scenario is an anisotropy in the arrival direction of the cosmic-ray electrons and positrons, which may be detectable by existing, or future, telescopes. The predicted anisotropy level is, at present, consistent with limits from Fermi-LAT and AMS-02. We argue that the large collecting area of Atmospheric Cherenkov Telescopes (ACTs) makes them optimal tools for...

  20. Anomalous radiative transitions

    CERN Document Server

    Ishikawa, Kenzo; Tobita, Yutaka

    2014-01-01

    Anomalous transitions involving photons derived by many-body interaction of the form, $\\partial_{\\mu} G^{\\mu}$, in the standard model are studied. This does not affect the equation of motion in the bulk, but makes wave functions modified, and causes the unusual transition characterized by the time-independent probability. In the transition probability at a time-interval T expressed generally in the form $P=T \\Gamma_0 +P^{(d)}$, now with $\\Gamma_0=0, P^{(d)} \

  1. Leptophilic dark matter confronts AMS-02 cosmic-ray positron flux

    Science.gov (United States)

    Cao, Qing-Hong; Chen, Chuan-Ren; Gong, Ti

    2017-02-01

    With the measurement of positron flux published recently by AMS-02 collaboration, we show how the leptophilic dark matter fits the observation. We obtain the percentages of different products of dark matter annihilation that can best describe the flux of high energy positrons observed by AMS. We show that dark matter annihilates predominantly into $\\tau\\tau$ pair, while both $ee$ and $\\mu\\mu$ final states should be less than $20\\%$. When gauge boson final states are included, the best branching ratio of needed $\\tau\\tau$ mode reduces.

  2. Explaining muon magnetic moment and AMS-02 positron excess in a gauged horizontal symmetric model

    CERN Document Server

    Tomar, Gaurav

    2015-01-01

    We extended the standard model with a fourth generation of fermions to explain the discrepancy in the muon magnetic moment and to describe the positron excess observed by AMS-02 experiment. We introduce a gauged $SU(2)_{HV}$ horizontal symmetry between the muon and the 4th generation lepton families and identified the 4th generation right-handed neutrino as the dark matter with mass $\\sim 700$ GeV. The dark matter annihilates through $SU(2)_{HV}$ gauge boson into final states $(\\mu^+ \\mu^-)$ and $(\

  3. Late decaying 2-component dark matter scenario as an explanation of the AMS-02 positron excess

    CERN Document Server

    Buch, Jatan; Rentala, Vikram

    2016-01-01

    The long standing anomaly in the positron flux as measured by the PAMELA and AMS-02 experiments could potentially be explained by dark matter annihilations. This scenario typically requires a large "boost factor" to be consistent with a thermal relic dark matter candidate produced via freeze-out. However, such an explanation has been considered to be disfavored by constraints from CMB observations on energy deposition during the recombination epoch. In this work, we construct a scenario for late-decaying two-component dark matter (LD2DM) with almost degenerate dark matter species. We show that such a scenario can explain the observed AMS-02 positron flux through an annihilation of the lighter dark matter species, while avoiding CMB constraints. The observed relic density can be correctly reproduced as well, with simple s-wave annihilation cross-sections. We demonstrate that the scenario is robust, subject to constraints from structure formation and CMB constraints on late-time energy depositions during the co...

  4. A possible dark matter annihilation signal in the AMS-02 antiproton data

    CERN Document Server

    Cui, Ming-Yang; Tsai, Yue-Lin Sming; Fan, Yi-Zhong

    2016-01-01

    A new approach has been adopted to probe the dark matter signal using the latest AMS-02 cosmic ray antiproton flux data. Different from previous studies, we do not assume specific propagation, injection, and solar modulation parameters when calculating the antiproton fluxes, but use the results inferred from the B/C ratio and proton data from the recent PAMELA/AMS-02 measurements instead. A joint likelihood method including the likelihood of these background parameters is established within the Bayesian framework. We find that a dark matter signal is favored with a high test statistic value of $\\sim 70$. The rest mass of the dark matter particles is $\\sim 30-70$ GeV and the velocity-averaged hadronic annihilation cross section is about $(1-6)\\times 10^{-26}$ cm$^{3}$s$^{-1}$, in agreement with that needed to account for the Galactic center GeV excess and/or the weak GeV emission from dwarf galaxies Reticulum 2 and Tucana III. Tight constraints on the dark matter annihilation models are also set in a wide mass...

  5. AMS-02 positron excess and indirect detection of three-body decaying dark matter

    Science.gov (United States)

    Cheng, Hsin-Chia; Huang, Wei-Chih; Huang, Xiaoyuan; Low, Ian; Sming Tsai, Yue-Lin; Yuan, Qiang

    2017-03-01

    We consider indirect detection of meta-stable dark matter particles decaying into a stable neutral particle and a pair of standard model fermions. Due to the softer energy spectra from the three-body decay, such models could potentially explain the AMS-02 positron excess without being constrained by the Fermi-LAT gamma-ray data and the cosmic ray anti-proton measurements. We scrutinize over different final state fermions, paying special attention to handling of the cosmic ray background and including various contributions from cosmic ray propagation with the help of the LIKEDM package. It is found that primary decays into an electron-positron pair and a stable neutral particle could give rise to the AMS-02 positron excess and, at the same time, stay unscathed against the gamma-ray and anti-proton constraints. Decays to a muon pair or a mixed flavor electron-muon pair may also be viable depending on the propagation models. Decays to all other standard model fermions are severely disfavored.

  6. Systematic study of the uncertainties in fitting the cosmic positron data by AMS-02

    CERN Document Server

    Yuan, Qiang

    2015-01-01

    The launch of AMS-02 opens a new era for cosmic ray physics with unprecedented precision of data, which are comparable with the laboratory measurements. The high precision data allow a quantitative study on the cosmic ray physics and give strict constraints on the nature of cosmic ray sources. However, the intrinsic errors from theoretical models to interpret the data become dominant over the errors in data. In the present work we try to give a systematic study on these uncertainties to explain, as an explicit example, the first AMS-02 positron fraction data, which shows the cosmic ray positron/electron excesses together with the PAMELA, Fermi-LAT measurements. The excesses can be attributed to contributions from new positron/electron sources, like pulsars or dark matter annihilation. The precise data give strict constraints on properties of the new sources. We study the systematic uncertainties from cosmic ray propagation, solar modulation, the $pp$ interaction models, the nuclei injection spectrum and so on...

  7. AMS-02 Positron Excess and Indirect Detection of Three-body Decaying Dark Matter

    CERN Document Server

    Cheng, Hsin-Chia; Huang, Xiaoyuan; Low, Ian; Tsai, Yue-Lin Sming; Yuan, Qiang

    2016-01-01

    We consider indirect detection of meta-stable dark matter particles decaying into a stable neutral particle and a pair of standard model fermions. Due to the softer energy spectra from the three-body decay, such models could potentially explain the AMS-02 positron excess without being constrained by the Fermi-LAT gamma-ray data and the cosmic ray anti-proton measurements. We scrutinize over different final state fermions, paying special attention to handling of the cosmic ray background and including various contributions from cosmic ray propagation with the help of the \\textsc{LikeDM} package. It is found that primary decays into an electron-positron pair and a stable neutral particle could give rise to the AMS-02 positron excess and, at the same time, stay unscathed against the gamma-ray and anti-proton constraints. Decays to a muon pair or a mixed flavor electron-muon pair may also be viable depending on the propagation models. Decays to all other standard model fermions are severely disfavored.

  8. Novel dark matter constraints from antiprotons in the light of AMS-02

    CERN Document Server

    Cuoco, Alessandro; Korsmeier, Michael

    2016-01-01

    We evaluate dark matter (DM) limits from cosmic-ray antiproton observations using the recent precise AMS-02 measurements. We properly take into account cosmic-ray propagation uncertainties fitting at the same time DM and propagation parameters, and marginalizing over the latter. We find a significant (~4.5 sigma) indication of a DM signal for DM masses near 80 GeV, with a hadronic annihilation cross-section close to the thermal value, sigma v ~3e-26 cm3s-1. Intriguingly, this signal is compatible with the DM interpretation of the Galactic center gamma-ray excess. Confirmation of the signal will require a more accurate study of the systematic uncertainties, i.e., the antiproton production cross-section, and modelling of the solar modulation effect. Interpreting the AMS-02 data in terms of upper limits on hadronic DM annihilation, we obtain strong constraints excluding a thermal annihilation cross-section for DM masses below about 50 GeV and in the range between approximately 150 and 500 GeV, even for conservat...

  9. AMS-02远程中心自动化生产系统的设计与实现%The design and implementation of AMS-02 automatic production system in remote computing center

    Institute of Scientific and Technical Information of China (English)

    单雅辉

    2014-01-01

    AMS-02实验的目的是利用独特的太空环境来研究宇宙中的暗物质、反物质以及测量宇宙射线的来源和组成。由于该实验具有数据量大、生产过程复杂、计算中心分布广泛的特点,本文首先介绍了AMS-02实验的背景和数据需求,然后详细地分析了其数据类型以及处理流程,最后通过整合关键技术,为 AMS-02实验远程计算中心设计并实现了一套基于脚本语言、轻量级、易移植的自动化生产管理系统,大幅度地提高了该实验中数据生产的效率。%Alpha Magnetic Spectrometer (AMS-02) experiment is using the unique environment of space to study the universe and its origin by searching for antimatter, dark matter while performing precision measurements of cosmic rays compositions. In consideration of the large amount of experimental data, the complexity of the production process, the widely dispersed regional center into account, this paper first introduces the background and data requirements of AMS-02 experiment, and then analyses experimental file types and data handling process in detail, and through the integration of key technologies, finally design and implement a lightweight, easy-transplant automatic data production system which is based on the scripting language for the remote computing centers, greatly improve the efficiency of the experimental data production in the AMS-02 experiment.

  10. AMS02 positron excess from decaying fermion DM with local dark gauge symmetry

    Directory of Open Access Journals (Sweden)

    P. Ko

    2015-02-01

    Full Text Available Positron excess observed by PAMELA, Fermi and AMS02 may be due to dark matter (DM pair annihilation or decay dominantly into muons. In this paper, we consider a scenario with thermal fermionic DM (χ with mass ∼O(1–2 TeV decaying into a dark Higgs (ϕ and an active neutrino (νa instead of the SM Higgs boson and νa. We first present a renormalizable model for this scenario with local dark U(1X gauge symmetry, in which the DM χ can be thermalized by Higgs portal and the gauge kinetic mixing. Assuming the dark Higgs (ϕ mass is in the range 2mμ

  11. Cosmic-Ray Positron Fraction Measurement with the AMS-02 Detector

    CERN Document Server

    AUTHOR|(CDS)2079577

    The study of Cosmic-Rays has proved to be of utmost importance in the understanding of the processes that govern our galaxy and has became a privileged field for the discovery of new physics. The current availability of precision measurements in a number of recent experiments such as PAMELA or Fermi, and in particular AMS-02, has provided a unique opportunity to challenge the theoretical framework that builds our comprehension of Nature. Certainly, the recent advent of new data on Cosmic-Ray electrons and positrons has raised disagreements with our current knowledge of production and propagation of Cosmic-Rays. The observation of an excess in the Cosmic-Ray electron spectrum has triggered enormous efforts to understand the origin of this anomaly, both from the theoretical and experimental points of view. In this context, AMS is a long awaited program, that among other objectives, will provide the most accurate measurement of the Cosmic-Ray electron spectrum, making possible to investigate a fundamental open q...

  12. ALICE Transition Radiation Detector (TRD), test beam.

    CERN Multimedia

    2003-01-01

    Electrons and positrons can be discriminated from other charged particles using the emission of transition radiation - X-rays emitted when the particles cross many layers of thin materials. To develop such a Transition Radiation Detector(TRD) for ALICE many detector prototypes were tested in mixed beams of pions and electrons, as in the example shown here.

  13. The AMS-02 detector on the International Space Station - The status after the first 5 years on orbit

    Science.gov (United States)

    Duranti, Matteo

    2017-03-01

    The Alpha Magnetic Spectrometer, AMS-02, detector is operating on the International Space Station (ISS) since May the 19th, 2011. More than 80 billion events have been collected by the instrument in the first 5 years of data taking. This unprecedented amount of data is being used to perform accurate measurements of the different Cosmic Rays (CR) components. In this contribution a review of the published results will be presented.

  14. Galactic cosmic-ray propagation in the light of AMS-02: Analysis of protons, helium, and antiprotons

    Science.gov (United States)

    Korsmeier, Michael; Cuoco, Alessandro

    2016-12-01

    We present novel constraints on cosmic-ray propagation in the Galaxy using the recent precise measurements of proton and helium spectra from AMS-02, together with preliminary AMS-02 data on the antiproton over proton ratio. To explore efficiently the large (up to 11-dimensional) parameter space we employ the nested-sampling algorithm as implemented in the MultiNest package, interfaced with the Galprop code to compute the model-predicted spectra. We use VOYAGER proton and helium data, sampling the local interstellar spectra, to constrain the solar modulation potential. We find that the turbulence of the Galactic magnetic field is well constrained, i.e., δ =0.3 0-0.02+0.03(stat )-0.04+0.10(sys ) , with uncertainties dominated by systematic effects. Systematic uncertainties are determined checking the robustness of the results to the minimum rigidity cut used to fit the data (from 1 GV to 5 GV), to the propagation scenario (convection vs no convection), and to the uncertainties in the knowledge of the antiproton production cross section. Convection and reacceleration are found to be degenerate and not well constrained singularly when using data above 5 GV. Using data above 1 GV reacceleration is required, vA=25 ±2 km /s , although this value might be significantly affected by the low-energy systematic uncertainty in the solar modulation. In a forthcoming companion paper, we investigate the constraints imposed by AMS-02 measurements on lithium, boron, and carbon.

  15. Transition undulator radiation as bright infrared sources

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.J. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/{gamma}, where {gamma} is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron`s longitudinal velocity as it enters and leaves the undulator. The characteristic of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets.

  16. Measurement of the cosmic positrons' spectrum with the experiment AMS-02 and search for exotic signals; Mesure du spectre de positons cosmiques avec l'experience AMS-02 et recherche de signaux exotiques

    Energy Technology Data Exchange (ETDEWEB)

    Pochon, J

    2005-06-15

    The AMS-02 experiment is a particle detector that will be installed on the international space station (ISS) in 2008 for at least 3 years. The physics motivations are cosmic ray measurements (e-, e+, p, p-bar, {gamma}, He, C,...), antimatter search for Z>2 and gamma ray studies from GeV to TeV. The HEAT experiment has measured positron spectrum up to 30 GeV, and shown a possible distortion around 8 GeV, which can be interpreted as a dark matter signal. The cosmic positrons spectrum measurement needs positron/proton separation close to 10{sup 5}, which will be obtained combining all AMS-02 sub-detectors. A neural network analysis has been developed on test beam data taken in 2002, to estimate the electron/proton rejection for the electromagnetic calorimeter. This technique, based on discriminant variables and which was tuned on data, was used to determine the positron acceptance combining other sub-detectors information. The number of conventional positrons can be estimated and AMS ability to detect cold dark matter signals has been determined. This study was presented for signal from supersymmetric neutralinos and from Kaluza-Klein stable particles. Fluxes are naturally too low to be detected. Signal can be enhanced thanks to local dark matter over-densities which appear naturally in galaxy formation models. A model for those over-densities has been tuned and presented. (author)

  17. Galactic cosmic-ray propagation in the light of AMS-02: I. Analysis of protons, helium, and antiprotons

    CERN Document Server

    Korsmeier, Michael

    2016-01-01

    We present novel constraints on cosmic-ray propagation in the Galaxy using the recent precise measurements of proton and helium spectra from AMS-02, together with preliminary AMS-02 data on the antiproton over proton ratio. To explore efficiently the large (up to eleven-dimensional) parameter space we employ the nested-sampling algorithm as implemented in the \\textsc{MultiNest} package, interfaced with the \\textsc{Galprop} code to compute the model-predicted spectra. We use VOYAGER proton and helium data, sampling the local inter-stellar spectra, to constrain the solar modulation potential. We find that the turbulence of the Galactic magnetic field is well constrained, i.e., $\\delta=0.30^{+0.03}_{-0.02}(stat)^{+0.10}_{-0.04}(sys)$, with uncertainties dominated by systematic effects. Systematic uncertainties are determined checking the robustness of the results to the minimum rigidity cut used to fit the data (from 1 GV to 5 GV), to the propagation scenario (convection vs no-convection), and to the uncertainti...

  18. Antiprotons from dark matter annihilation through light mediators and a possible excess in AMS-02 $\\pbar/p$ data

    CERN Document Server

    Huang, Xian-Jun; Wu, Yue-Liang; Zhang, Wei-Hong; Zhou, Yu-Feng

    2016-01-01

    We show that in the scenario where dark matter (DM) particles annihilate through light mediators, the energy spectra of the final state cosmic-ray particles depend strongly on the mediator mass. For final state antiprotons, a spectrum with relatively narrow peak occurs when the mediator mass is comparable to the $\\pbar p$ production threshold. Of interest, the latest AMS-02 data on the $\\pbar/p$ flux ratio hint at a bump-like excess over the expected background in the energy range $\\sim100-450$ GeV. We show that such a light mediator scenario is favoured by the latest AMS-02 data over the scenarios of DM direct annihilation into the standard model particles and that of antiprotons produced from inside supernova remnants (SNRs), and is consistent with the upper limits derived from the Fermi-LAT data on the gamma rays towards the dwarf spheroidal galaxies. The $\\pbar/p$ flux ratio with energy above 450 GeV is predicted to fall with energy quickly, which can be easily distinguished from the other two scenarios a...

  19. Particle identification by Cherenkov and transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, R.S.

    1980-09-01

    The Cherenkov counter has a role as a particle identifier for velocities which are too high for Time-of-Flight to be used, and too low for transition radiation detectors to give a useable signal. In beam lines the compensated differential counter is capable of giving the best resolution, but at high momenta the restriction on the spread of particle directions gives unacceptable limits on the beam acceptance. The transition radiation detectors being developed to identify hadrons at relatively low momentum do not have this restriction and might be used instead. For particles produced in an interaction, the ring imaging type of Cherenkov should give the best coverage for multiparticle events, but a threshold counter is much simpler, cheaper and faster where it can give adequate separation. Again at high values of ..gamma.. the resolution of Cherenkov counters will fail and some form of transition radiation detector will be necessary.

  20. Secondary cosmic ray nuclei in the light of the single source model and comparison with recent AMS-02 data

    Science.gov (United States)

    Erlykin, A. D.; Wolfendale, A. W.

    2016-10-01

    Evidence for a local ‘single source’ of cosmic rays is amassing by way of the recent precise measurements of various cosmic ray energy spectra from the AMS-02 instrument. To observations of individual cosmic ray nuclei, electrons, positrons and antiprotons must now be added the determination of the boron-to-carbon ratio and the energy spectrum of lithium to 2000 GV with high precision. Our analysis leads us to claim that, with certain assumptions about propagation in the Galaxy, the results confirm our arguments regarding the presence of a local single source, perhaps, a supernova remnant (SNR). An attempt is made to determine some of the properties of this SNR and its progenitor star.

  1. Charmonium meson and hybrid radiative transitions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Peng [Indiana U., JLAB; Yépez-Martínez, Tochtli [Indiana U.; Szczepaniak, Adam P. [Indiana U., JLAB

    2014-06-01

    We consider the non-relativistic limit of the QCD Hamiltonian in the Coulomb gauge, to describe radiative transitions between conventional charmonium states and from the lowest multiplet of cc¯ hybrids to charmonium mesons. The results are compared to potential quark models and lattices calculations.

  2. Spatial Dependent Diffusion of Cosmic Rays and the Excess of Primary Electrons Derived from High Precision Measurements by AMS-02

    CERN Document Server

    Jin, C; Hu, H B

    2016-01-01

    The precise spectra of Cosmic Ray (CR) electrons and positrons have been published by the measurement of AMS-02. It is reasonable to regard the difference between the electrons and positrons spectra ( $\\triangle \\Phi= \\Phi_{e^-}-\\Phi_{e^+}$ ) as being dominated by primary electrons. Noticing that the resulting electron spectrum shows no sign of spectral softening above 20 GeV, which is in contrast with the prediction of standard model. In this work, we generalize the analytic one dimensional two-halo model of diffusion to a three dimensional realistic calculation by implementing a spatial variant diffusion coefficients in DRAGON package. As a result, we can reproduce the spectral hardening of protons observed by several experiments, and predict an excess of high energy primary electrons which agrees with the measurement reasonably well. Unlike the break spectrum obtained for protons, the model calculation predicts a smooth electron excess and thus slightly over predicts the flux from tens of GeV to 100GeV. To...

  3. Radiative Transitions in Charmonium from Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Jozef Dudek; Robert Edwards; David Richards

    2006-01-17

    Radiative transitions between charmonium states offer an insight into the internal structure of heavy-quark bound states within QCD. We compute, for the first time within lattice QCD, the transition form-factors of various multipolarities between the lightest few charmonium states. In addition, we compute the experimentally unobservable, but physically interesting vector form-factors of the {eta}{sub c}, J/{psi} and {chi}{sub c0}. To this end we apply an ambitious combination of lattice techniques, computing three-point functions with heavy domain wall fermions on an anisotropic lattice within the quenched approximation. With an anisotropy {xi} = 3 at a{sub s} {approx} 0.1 fm we find a reasonable gross spectrum and a hyperfine splitting {approx}90 MeV, which compares favorably with other improved actions. In general, after extrapolation of lattice data at non-zero Q{sup 2} to the photopoint, our results agree within errors with all well measured experimental values. Furthermore, results are compared with the expectations of simple quark models where we find that many features are in agreement; beyond this we propose the possibility of constraining such models using our extracted values of physically unobservable quantities such as the J/{psi} quadrupole moment. We conclude that our methods are successful and propose to apply them to the problem of radiative transitions involving hybrid mesons, with the eventual goal of predicting hybrid meson photoproduction rates at the GlueX experiment.

  4. Performance of the ATLAS Transition Radiation Tracker

    CERN Document Server

    Adelman, J; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker (TRT) is a large straw tube tracking system that is the outermost of the three subsystems of the ATLAS Inner Detector (ID). With over 350,000 readout channels, the TRT provides both excellent particle identification capabilities and electron-pion separation, as well as contributing significantly to the resolution for high-pt tracks in the ID. As the instantaneous luminosity of the LHC increases, the occupancy of the TRT will increase as well. The low-occupancy tracking resolution and efficiency will be presented, as will be studies of resolution and PID at higher occupancies.

  5. Possible primary-electron-spectrum hardening at $\\sim 240$ GeV: Implications for AMS-02 observation and the physical origin of cosmic ray excesses

    CERN Document Server

    Feng, Lei; He, Hao-Ning; Dong, Tie-Kuang; Fan, Yi-Zhong; Chang, Jin

    2014-01-01

    The data collected by ATIC, CREAM and PAMELA all display remarkable cosmic-ray-nuclei spectrum hardening above the magnetic rigidity $\\sim$ 240 GV. One natural speculation is that the primary electron spectrum also gets hardened at $\\sim 240$ GeV, which can partly account for the electron/positron total spectrum excess discovered by ATIC, HESS and Fermi-LAT. The subsequent positron-to-electron ratio may get flattened or even decreased, depending on the degree of the primary electron spectrum hardening. Such modification is detectable for AMS-02, a mission dedicated to measure the high energy cosmic ray spectra with unprecedented accuracy. The spectrum hardening of both primary-electrons and nuclei at $\\sim 240$ GV, if confirmed by AMS-02 in the future, is likely attributed to a "nearby" supernova-remnant-like source with a lifetime $\\lesssim 10^{13}$ s. Possible dark matter origin of the positron excess revealed by PAMELA is also investigated.

  6. Cosmic gamma ray detection and discovery potential with the AMS-2 spectrometer; Detection de rayons {gamma} cosmiques et potentiel de decouvertes avec le spectrometre AMS-02

    Energy Technology Data Exchange (ETDEWEB)

    Girard, L

    2004-12-15

    Yet designed to measure charged component of the cosmic rays, the foreseen Alpha Magnetic Spectrometer (AMS-02) could also release {gamma}-ray studies, in the energy range from GeV to TeV, using the tracker system, for {gamma}-rays converted in e{sup +}e{sup -} pair, and the electromagnetic calorimeter. In the first part of the thesis are described the calibrations and the performances of the engineering model of the calorimeter, obtained from the analysis of data taken during a test-beam performed at CERN in July 2002. In the second part of the thesis, the AMS-02 discovery potential for {gamma}-astrophysics is presented. While exposure maps of the {gamma}--sky are computed for one year of data taking with the {gamma}--detectors, the acceptance of the calorimeter is obtained from Monte-Carlo simulations. The AMS-02 potential is then estimated for signals from the Vela pulsar and for some supersymmetric signals from the Galactic Center. (author)

  7. Study of the photomultiplier R7600-00-M4 for the purpose of the electromagnetic calorimeter in the AMS-02 experiment

    CERN Document Server

    Kossakowski, R; Dubois, J M; Fougeron, D; Hermel-Richard; Sottile, R; Vialle, J P

    2002-01-01

    The properties of the 4-channels photomultiplier R7600-00-M4 from Hamamatsu were extensively studied for use in the AMS-02 electromagnetic calorimeter. A scan of the photocathode with a precision in position better than 0.1 mm was performed in order to measure the position dependence of the sensitivity and of the cross talk between pixels. The influence of the magnetic field applied in X, Y and Z directions was measured. The dynamic range of the photomultiplier was measured and optimized by the appropriate choice of the high voltage divider and of the value of the high voltage.

  8. Study of the photomultiplier R7600-00-M4 for the purpose of the electromagnetic calorimeter in the AMS-02 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kossakowski, Roman; Audemer, Jean Charles; Dubois, Jean Marc; Fougeron, Denis; Hermel Richard; Sottile, Rico; Vialle, Jean Pierre [Laboratoire d' Annecy-Le-Vieux de Physique des Particules, LAPP, IN2P3-CNRS, BP 110, F-74941 Annecy-Le-Vieux (France)

    2002-07-01

    The properties of the 4-channels photomultiplier R7600-00-M4 from Hamamatsu were extensively studied for use in the AMS-02 electromagnetic calorimeter. A scan of the photocathode with a precision in position better than 0.1 mm was performed in order to measure the position dependence of the sensitivity and of the cross talk between pixels. The influence of the magnetic field applied in X, Y and Z directions was measured. The dynamic range of the photomultiplier was measured and optimized by the appropriate choice of the high voltage divider and of the value of the high voltage. (authors)

  9. Gravitational radiation from first-order phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Child, Hillary L.; Giblin, John T. Jr., E-mail: childh@kenyon.edu, E-mail: giblinj@kenyon.edu [Department of Physics, Kenyon College, 201 North College Road, Gambier, OH 43022 (United States)

    2012-10-01

    It is believed that first-order phase transitions at or around the GUT scale will produce high-frequency gravitational radiation. This radiation is a consequence of the collisions and coalescence of multiple bubbles during the transition. We employ high-resolution lattice simulations to numerically evolve a system of bubbles using only scalar fields, track the anisotropic stress during the process and evolve the metric perturbations associated with gravitational radiation. Although the radiation produced during the bubble collisions has previously been estimated, we find that the coalescence phase enhances this radiation even in the absence of a coupled fluid or turbulence. We comment on how these simulations scale and propose that the same enhancement should be found at the Electroweak scale; this modification should make direct detection of a first-order electroweak phase transition easier.

  10. Gravitational Radiation from First-Order Phase Transitions

    CERN Document Server

    Child, Hillary L

    2012-01-01

    It is believed that first order phase transitions at or around the GUT scale will produce high-frequency gravitational radiation. This radiation is a consequence of the collisions and coalescence of multiple bubbles during the transition. We employ high-resolution lattice simulations to numerically evolve a system of bubbles, track the anisotropic stress during the process and evolve the metric perturbations associated with gravitational radiation. Although the radiation produced during the bubble collisions has previously been estimated, we find that the coalescence phase that greatly enhances this radiation even in the absence of turbulence. We comment on how these simulations scale and propose that the same enhancement should be found at the Electroweak scale; this modification should make direct detection of a first-order electroweak phase transition easier.

  11. Design of a transition radiation detector for cosmic rays

    Science.gov (United States)

    Hartmann, G.; Mueller, D.; Prince, T.

    1975-01-01

    Transition radiation detectors consisting of sandwiches of plastic foam radiators and multiwire proportional chambers can be used to identify cosmic ray particles with energies gamma ? E/mc-squared is greater than 10 to the 3rd and to measure their energy in the region gamma is roughly equal to 10 to the 3rd

  12. ATLAS Transition Radiation Tracker test-beam results

    CERN Document Server

    Åkesson, T; Baker, K; Baron, S; Benjamin, D; Bertelsen, H; Bondarenko, V; Bychkov, V; Callahan, J; Capéans-Garrido, M; Cardiel-Sas, L; Catinaccio, A; Cetin, S A; Cwetanski, Peter; Dam, M; Danielsson, H; Dittus, F; Dolgoshein, B A; Dressnandt, N; Driouichi, C; Ebenstein, W L; Eerola, Paule Anna Mari; Farthouat, Philippe; Fedin, O; Froidevaux, D; Gagnon, P; Grichkevitch, Y; Grigalashvili, N S; Hajduk, Z; Hansen, P; Kayumov, F; Keener, P T; Kekelidze, G D; Khristatchev, A; Konovalov, S; Koudine, L; Kovalenko, S; Kowalski, T; Kramarenko, V A; Krüger, K; Laritchev, A; Lichard, P; Luehring, F C; Lundberg, B; Maleev, V; Markina, I; McFarlane, K W; Mialkovski, V; Mitsou, V A; Mindur, B; Morozov, S; Munar, A; Muraviev, S; Nadtochy, A; Newcomer, F M; Ögren, H O; Oh, S H; Oleshko, S; Olszowska, J; Passmore, S; Patritchev, S; Peshekhonov, V D; Petti, R; Price, M; Rembser, C; Rohne, O; Romaniouk, A; Rust, D R; Ryabov, Yu; Shchegelskii, V; Seliverstov, D M; Shin, T; Shmeleva, A; Smirnov, S; Sosnovtsev, V V; Soutchkov, V; Spiridenkov, E; Tikhomirov, V; Van Berg, R; Vassilakopoulos, V I; Vassilieva, L; Wang, C; Williams, H H; Zalite, A

    2004-01-01

    Several prototypes of the Transition Radiation Tracker for the ATLAS experiment at the LHC have been built and tested at the CERN SPS accelerator. Results from detailed studies of the straw-tube hit registration efficiency and drift-time measurements and of the pion and electron spectra without and with radiators are presented. (10 refs).

  13. Coherent transition radiation from REB in plasma ripple

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The coherent transition-radiation emission from an underdense relativistic beam of electrons, travelling through a dense plasma ripple, was studied. The evolution of this radiation field is described by a set of self-consistent pendulum-wave equations. Analytic calculations of the small-signal gain and numerical computations of the nonlinear saturation of this emission are presented. It is shown that such a device may provide a source of tunable coherent radiation ranging from the microwave to the infrared region.

  14. The discrimination between cosmic positrons and protons with the Transition Radiation Detector of the AMS experiment on the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Millinger, Mark

    2012-10-08

    The aim of this thesis is the development and validation of a particle identification method with the Transition Radiation Detector (TRD) of the Alpha Magnetic Spectrometer AMS-02 to allow for the determination of the positron fraction in the cosmic lepton flux. Independent measurements indicate that a significant amount of about 23% of the energy density in the universe consists of an unknown mass contribution, the so-called Dark Matter. The Neutralino, as the most popular Dark Matter particle candidate, may produce an additional signal in the spectrum of cosmic rays. The fraction of positrons in the cosmic lepton flux possibly contains such a Dark Matter signal at high particle momenta. The currently most precise measurements in the region of this excess are provided by the satellite-borne PAMELA and Fermi detectors. Momentumdependent systematic uncertainties, especially the mis-identification of protons as positrons, could imitate the signal. However, if this positron excess is produced by Dark Matter the fraction should decrease above a theoretical energy threshold to the expectations, based on particle propagation. The energy region measured up to now does not show such a progress. Due to its significantly increased event statistics and its capability to measure up to higher particle energies, this signature could be observed with AMS-02. The number of events, which can be recorded by a detector, is limited by the combination of aperture and observable solid angle, quantified by the geometrical acceptance, and the observation time. As the cosmic particle flux follows a power-law in particle momentum with exponent {gamma} {approx} -3, the observable momentum interval is thus constrained by statistics. Due to its large geometrical acceptance of about 0.5 m{sup 2}sr, its long observation time of at least 9 years and its high proton suppression factor of >or similar 10{sup 6} AMS-02 will record large and clean lepton samples and thus provide a precise measurement

  15. Boundary conditions and generalized functions in a transition radiation problem

    Science.gov (United States)

    Villavicencio, M.; Jiménez, J. L.

    2017-03-01

    The aim of this work is to show how all the components of the electromagnetic field involved in the transition radiation problem can be obtained using distribution functions. The handling of the products and derivatives of distributions appearing in the differential equations governing transition radiation, allows to obtain the necessary boundary conditions, additional to those implied by Maxwell's equations, in order to exactly determine the longitudinal components of the electromagnetic field. It is shown that this method is not only useful but it is really convenient to achieve a full analysis of the problem.

  16. Radiative transitions in mesons in a non relativistic quark model

    OpenAIRE

    Bonnaz, R.; Silvestre-Brac, B.; Gignoux, C.

    2001-01-01

    In the framework of the non relativistic quark model, an exhaustive study of radiative transitions in mesons is performed. The emphasis is put on several points. Some traditional approximations (long wave length limit, non relativistic phase space, dipole approximation for E1 transitions, gaussian wave functions) are analyzed in detail and their effects commented. A complete treatment using three different types of realistic quark-antiquark potential is made. The overall agreement with experi...

  17. Radiative transitions in mesons in a non relativistic quark model

    CERN Document Server

    Bonnaz, R; Gignoux, C

    2002-01-01

    In the framework of the non relativistic quark model, an exhaustive study of radiative transitions in mesons is performed. The emphasis is put on several points. Some traditional approximations (long wave length limit, non relativistic phase space, dipole approximation for E1 transitions, gaussian wave functions) are analyzed in detail and their effects commented. A complete treatment using three different types of realistic quark-antiquark potential is made. The overall agreement with experimental data is quite good, but some improvements are suggested.

  18. Comparison of Coherent Smith-Purcell radiation and Coherent Transition Radiation

    CERN Document Server

    Khodnevych, Vitalii; Bezshyyko, Oleg

    2016-01-01

    Smith-Purcell radiation and Transition Radiation are two radiative phenomenon that occur in charged particles accelerators. For both the emission can be significantly enhanced with sufficiently short pulses and both can be used to measure the form factor of the pulse. We compare the yield of these phenomenon in different configurations and look at their application as bunch length monitors, including background filtering and rejection. We apply these calculations to the specific case of the CLIO Free Electron laser.

  19. Recent progress with the Transition Radiation Tracker

    CERN Document Server

    Froidevaux, D

    Start-up of end-cap assembly in Russia On July 2nd at PNPI (first photo) and on August 1st at JINR Dubna (second photo), the first straws were inserted into the first 4-plane end-cap wheels, each containing 3072 straws. The straws were glued, the radiator stacks were installed and the PNPI wheel was tested for gas leaks. An initial large leak rate was observed and fixed by increasing somewhat the amount of glue around each straw end-piece and improving the leak-tightness of the testing equipment itself. PNPI will assemble a total of 48 4-plane wheels of type A using two assembly lines. JINR Dubna will assemble a total of 32 4-plane wheels of type B using a single assembly line. The next steps are the gluing of the so-called active webs (printed circuit boards connecting high voltage and signal lines from straw/wire to HV supply and front-end boards), followed by wiring, and will take place in November. PNPI and JINR Dubna should start mass production in February-March next year. Barrel module produc...

  20. The transition radiation. 2. experimental study of the optical transition radiation; Le rayonnement de transition: 2. etude experimentale du rayonnement de transition optique

    Energy Technology Data Exchange (ETDEWEB)

    Couillaud, Ch.; Haouat, G.; Seguin, S.; Striby, S

    1999-07-01

    Optical-transition-radiation-based diagnostics have been widely used for many years on electron accelerators in order to measure beam energy and transverse and longitudinal emittances. These diagnostics are very attractive for high brightness electron beams used as drivers for radiation sources. Such diagnostics have been performed on the ELSA facility (18 MeV electron energy, 100 A peak current) using both a single interface and an OTR-Wartski interferometer. We present the accelerator, the experimental set-up and the method for analyzing the OTR angular distribution. Then, the experimental results are described and compared with those from the three gradient method. In addition, we present a beam energy measurement using OTR interferogram analysis. (author)

  1. Classical theory of resonant transition radiation in multilayer structures.

    Science.gov (United States)

    Pardo, B; André, J M

    2001-01-01

    A rigorous classical electromagnetic theory of the transition radiation in finite and infinite multilayer structures is presented. It makes the standard results of thin-film optics, such as the matrix formalism, accountable; it allows thus an exact treatment of the propagation of the waves induced by the electron. This method is applied to the particular case of the periodic structures to treat the resonant transition radiation (RTR). It is noted that the present theory gives, in the hard x-ray domain, results previously published. The reason for this approach is to make the numerical calculations rigorous and easy. The numerical results of our theory are compared to experimental RTR data obtained recently by Yamada et al. [Phys. Rev. A 59, 3673 (1999)] with a nickel-carbon multilayer structure.

  2. Successful beam tests for ALICE Transition Radiation Detector

    CERN Multimedia

    2002-01-01

    Another round of beam tests of prototypes for the Transition Radiation Detector (TRD) for ALICE has been completed and there are already some good results. Mass production of the components of the detector will start early next year.   Top view of the setup for the Transition Radiation Detector prototype tests at CERN.On the left, can be seen the full-scale TRD prototype together with four smaller versions. These are busy days for the TRD (Transition Radiation Detector) team of ALICE. Twenty people - mainly from Germany, but also from Russia and Japan - were working hard during the beam tests this autumn at CERN to assess the performance of their detector prototypes. Analysis of the data shows that the TRD can achieve the desired physics goal even for the highest conceivable multiplicities in lead-lead collisions at the LHC. In its final configuration in the ALICE experiment, the TRD will greatly help in identifying high-momentum electrons, which are 'needles in a haystack' that consists mostly of...

  3. Energy levels and radiative rates for transitions in Ti VII

    CERN Document Server

    Aggarwal, KM

    2013-01-01

    We report calculations of energy levels, radiative rates, oscillator strengths and line strengths for transitions among the lowest 231 levels of Ti VII. The general-purpose relativistic atomic structure package ({\\sc grasp}) and flexible atomic code ({\\sc fac}) are adopted for the calculations. Radiative rates, oscillator strengths and line strengths are provided for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions among the 231 levels, although calculations have been performed for a much larger number of levels (159,162). In addition, lifetimes for all 231 levels are listed. Comparisons are made with existing results and the accuracy of the data is assessed. In particular, the most recent calculations reported by Singh {\\em et al} [Can J. Phys. {\\bf 90} (2012) 833] are found to be unreliable, with discrepancies for energy levels of up to 1 Ryd and for radiative rates of up to five orders of magnitude for several transitions, particularly the we...

  4. A transition radiation detector for kaon/pion separation

    Energy Technology Data Exchange (ETDEWEB)

    Baake, M.; Diekmann, B.; Gebert, F.; Heinloth, K.; Holzkamp, S.; Koersgen, G.; Voigtlaender-Tetzner, A. (Bonn Univ. (Germany, F.R.)); Bagdassarian, L.; Kazarian, C.; Oganessian, A. (Erevanskij Gosudarstvennyj Univ. (USSR))

    1989-09-01

    The experiment WA69 at the CERN Omega spectrometer facility has studied fixed target photon and hadron production of inclusive hadronic final states with tagged photon beams of 65-175 GeV in comparison to charged hadron beams ({pi} and K) of 80 and 140 GeV fixed energies. For the identification of final state pions and kaons above 100 GeV/c a transition radiation detector (TRAD) has been developed. This detector was constructed of 12 modules, each consisting of a polypropylene fibre radiator and a proportional chamber with a xenon/methane gas mixture to detect the transition radiation produced by fast moving charged particles. We give a description of the detector setup and working conditions. As a first result obtained with the TRAD the ratio of photoproduced kaons and pions in the extreme forward regime (x{sub F}>0.7 and -t<1 GeV{sup 2}) is measured to be 10.2(+-1.7)% which is in agreement with VDM predictions. (orig.).

  5. A Study of Radiative Bottomonium Transitions using Converted Photons

    Energy Technology Data Exchange (ETDEWEB)

    Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /INFN, Bari; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; Hearty, C.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-08-15

    The authors use (111 {+-} 1) million {Upsilon}(3S) and (89 {+-} 1) million {Upsilon}(2S) events recorded by the BABAR detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions betwen bottomonium states using photons that have been converted to e{sup +}e{sup -} pairs by the detector material. They observe {Upsilon}(3S) {yields} {gamma}{chi}{sub b0,2}(1P) decay, make precise measurements of the branching fractions for {chi}{sub b1,2}(1P, 2P) {yields} {gamma}{Upsilon}(1S) and {chi}{sub b1,2}(2P) {yields} {gamma}{Upsilon}(2S) decays, and search for radiative decay to the {eta}{sub b}(1S) and {eta}{sub b}(2S) states.

  6. Simulation of transition radiation based beam imaging from tilted targets

    Science.gov (United States)

    Sukhikh, L. G.; Kube, G.; Potylitsyn, A. P.

    2017-03-01

    Transverse beam profile diagnostics in linear electron accelerators is usually based on direct imaging of a beam spot via visible transition radiation. In this case the fundamental resolution limit is determined by radiation diffraction in the optical system. A method to measure beam sizes beyond the diffraction limit is to perform imaging dominated by a single-particle function (SPF), i.e. when the recorded image is dominated not by the transverse beam profile but by the image function of a point source (single electron). Knowledge of the SPF for an experimental setup allows one to extract the transverse beam size from an SPF dominated image. This paper presents an approach that allows one to calculate two-dimensional SPF dominated beam images, taking into account the target inclination angle and the depth-of-field effect. In conclusion, a simple fit function for beam size determination in the case under consideration is proposed and its applicability is tested under various conditions.

  7. Radiative data for allowed transitions in Ni XXV

    Energy Technology Data Exchange (ETDEWEB)

    Tully, John A [Departement Cassiopee, Observatoire de la Cote d' Azur, BP 4229, 06304 Nice Cedex 4 (France); Chidichimo, Marita C [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2004-02-14

    Using Hibbert's configuration interaction program CIV3, which allows for relativistic effects by means of the Breit-Pauli approximation, we have computed radiative data for the 272 optically allowed transitions between levels i = 2l{sub 1} 2l{sub 2} S'L'J' and j = 2l{sub 3} n{sub 4}l{sub 4} SLJ with n{sub 4} = 2, 3, 4 in Be-like Ni XXV. Oscillator strengths f, transition probabilities A, line wavelengths {lambda} and energies E{sub ij} in cm{sup -1} are tabulated. We make detailed comparisons with related work done by other authors during the period 1977 to 2000.

  8. Glass transition near the free surface studied by synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sikorski, M.

    2008-06-15

    A comprehensive picture of the glass transition near the liquid/vapor interface of the model organic glass former dibutyl phthalate is presented in this work. Several surface-sensitive techniques using x-ray synchrotron radiation were applied to investigate the static and dynamic aspects of the formation of the glassy state from the supercooled liquid. The amorphous nature of dibutyl phthalate close to the free surface was confirmed by grazing incidence X-ray diffraction studies. Results from X-ray reflectivity measurements indicate a uniform electron density distribution close to the interface excluding the possibility of surface freezing down to 175 K. Dynamics on sub-{mu}m length-scales at the surface was studied with coherent synchrotron radiation via x-ray photon correlation spectroscopy. From the analysis of the dispersion relation of the surface modes, viscoelastic properties of the dibutyl phthalate are deduced. The Kelvin-Voigt model of viscoelastic media was found to describe well the properties of the liquid/vapor interface below room temperature. The data show that the viscosity at the interface matches the values reported for bulk dibutyl phthalate. The scaled relaxation rate at the surface agrees with the bulk data above 210 K. Upon approaching the glass transition temperature the free surface was observed to relax considerably faster close to the liquid/vapor interface than in bulk. The concept of higher relaxation rate at the free surface is also supported by the results of the quasielastic nuclear forward scattering experiment, during which dynamics on molecular length scales around the calorimetric glass transition temperature is studied. The data were analyzed using mode-coupling theory of the glass transition and the model of the liquid(glass)/vapor interface, predicting inhomogeneous dynamics near the surface. The quasielastic nuclear forward scattering data can be explained when the molecular mobility is assumed to decrease with the increasing

  9. Supported transition metal nanomaterials: Nanocomposites synthesized by ionizing radiation

    Science.gov (United States)

    Clifford, D. M.; Castano, C. E.; Rojas, J. V.

    2017-03-01

    Nanostructures decorated with transition metal nanoparticles using ionizing radiation as a synthesis method in aqueous solutions represents a clean alternative to existing physical, chemical and physicochemical methods. Gamma irradiation of aqueous solutions generates free radicals, both oxidizing and reducing species, all distributed homogeneously. The presence of oxidant scavengers in situ during irradiation generates a highly reductive environment favoring the reduction of the metal precursors promoting seed formation and nanoparticle growth. Particle growth is controlled by addition of surfactants, polymers or various substrates, otherwise referred to as supports, which enhance the formation of well dispersed nanoparticles. Furthermore, the combination of nanoparticles with supports can offer desirable synergisms not solely presented by the substrate or nanoparticles. Thus, supported nanoparticles offer a huge diversity of applications. Among the ionizing radiation methods to synthesize nanomaterials and modify their characteristics, gamma irradiation is of growing interest and it has shown tremendous potential in morphological control and distribution of particle size by judiciously varying parameters including absorbed dose, dose rate, concentration of metal precursor, and stabilizing agents. In this work, major advances on the synthesis of supported nanoparticles through gamma irradiation are reviewed as well as the opportunities to develop and exploit new composites using gamma-rays and other accessible ionizing radiation sources such as X-rays.

  10. Simulation of transition radiation and electron identification ability of the ATLAS TRT

    DEFF Research Database (Denmark)

    Klinkby, Esben Bryndt

    2013-01-01

    The Transition Radiation Tracker (TRT) is the outer most tracking detector of the ATLAS experiment. In addition as functioning as atracking detector, it is capable of providing particle identification information through the emission and subsequent absorption and detection of transition radiation....... Below the effort of simulating transition radiation production and detector response is discussed, with emphasis on the data/simulation agreement and tuning. © 2012 CERN. Published by Elsevier B.V. All rights reserved....

  11. Aging studies for the ATLAS Transition Radiation Tracker (TRT)

    CERN Document Server

    Åkesson, T; Bondarenko, V; Capéans-Garrido, M; Catinaccio, A; Cwetanski, Peter; Danielsson, H; Dittus, F; Dolgoshein, B A; Dressnandt, N; Ebenstein, W L; Eerola, Paule Anna Mari; Farthouat, Philippe; Fedin, O; Froidevaux, D; Gavrilenko, I; Grichkevitch, Y; Gagnon, P; Hajduk, Z; Keener, P T; Kekelidze, G D; Konovalov, S; Kowalski, T; Kramarenko, V A; Laritchev, A; Lichard, P; Lundberg, B; Luehring, F C; Markina, I; Manara, A; McFarlane, K; Mitsou, V; Muraviev, S; Newcomer, F M; Ogren, H; Oh, S H; Olszowska, J; Peshekhonov, V D; Rembser, C; Romaniouk, A; Rhone, O; Rust, D R; Shchegelskii, V; Shmeleva, A; Smirnov, S; Smirnova, L N; Sosnovtsev, V V; Sutchkov, S; Tartarelli, F; Tikhomirov, V; Van Berg, R; Vassilieva, L; Wang, C; Williams, H H

    2003-01-01

    A summary of the aging and material validation studies carried out for the ATLAS Transition Radiation Tracker (TRT) is presented. Particular emphasis is put on the different phenomena observed in straw tubes operating with the chosen Xe/CF//4/CO//2 mixture. The most serious effects observed are silicon deposition on the anode wire and damage of the anode wire gold plating. Etching phenomena and active radical effects are also discussed. With a careful choice of all materials and components, and with good control of the water contamination in the active gas, the ATLAS TRT will operate reliably for 10 years at the LHC design luminosity. To demonstrate this fully, more work is still needed on the gas system purification elements, in particular to understand their interplay with the active species containing fluorine created in the avalanche process under irradiation.

  12. Tracking properties of the ATLAS Transition Radiation Tracker (TRT)

    CERN Document Server

    Krasnopevtsev, Dimitriy; The ATLAS collaboration

    2016-01-01

    The tracking performance parameters of the ATLAS Transition Radiation Tracker (TRT) as part of the ATLAS Inner Detector are described for different data taking conditions in proton-proton, proton-lead and heavy ion collisions at the Large Hadron Collider (LHC). These studies are performed using data collected during the first and the second periods of LHC operation and are compared with Monte Carlo simulations. The performance of the TRT, operating with different gas mixtures (Xenon-based and Argon-based) and for high track multiplicities is presented. These studies show that the tracking performance of the TRT with these two gas mixtures is similar and that the detector still provides a significant contribution to the particle momentum measurement of the overall Inner Detector of the ATLAS experiment.

  13. Recent aging studies for the ATLAS transition radiation tracker

    CERN Document Server

    Capéans-Garrido, M; Anghinolfi, F; Arik, E; Baker, O K; Baron, S; Benjamin, D; Bertelsen, H; Bondarenko, V; Bychkov, V; Callahan, J; Cardiel-Sas, L; Catinaccio, A; Cetin, S A; Cwetanski, Peter; Dam, M; Danielsson, H; Dittus, F; Dologshein, B; Dressnandt, N; Driouichi, C; Ebenstein, W L; Eerola, Paule Anna Mari; Farthouat, Philippe; Fedin, O; Froidevaux, D; Gagnon, P; Grichkevitch, Y; Grigalashvili, N S; Hajduk, Z; Hansen, P; Kayumov, F; Keener, P T; Kekelidze, G D; Khristatchev, A; Konovalov, S; Koudine, L; Kovalenko, S; Kowalski, T; Kramarenko, V A; Krüger, K; Laritchev, A; Lichard, P; Luehring, F C; Lundberg, B; Maleev, V; Markina, I; McFarlane, K W; Mialkovski, V; Mindur, B; Mitsou, V A; Morozov, S; Munar, A; Muraviev, S; Nadtochy, A; Newcorner, F M; Ogren, H; Oh, S H; Olszowska, J; Passmore, S; Patritchev, S; Peshekhonov, V D; Petti, R; Price, M; Rembser, C; Rohne, O; Romaniouk, A; Rust, D R; Ryabov, Yu; Ryzhov, V; Shchegelskii, V; Seliverstov, D M; Shin, T; Shmeleva, A; Smirnov, S; Sosnovtsev, V V; Soutchkov, V; Spiridenkov, E; Szczygiel, R; Tikhomirov, V; Van Berg, R; Vassilakopoulos, V I; Vassilieva, L; Wang, C; Williams, H H; Zalite, A

    2004-01-01

    The transition radiation tracker (TRT) is one of the three subsystems of the inner detector of the ATLAS experiment. It is designed to operate for 10 yr at the LHC, with integrated charges of similar to 10 C/cm of wire and radiation doses of about 10 Mrad and 2 multiplied by 10**1**4 neutrons/cm**2. These doses translate into unprecedented ionization currents and integrated charges for a large-scale gaseous detector. This paper describes studies leading to the adoption of a new ionization gas regime for the ATLAS TRT. In this new regime, the primary gas mixture is 70%Xe-27%CO**2-3%O**2. It is planned to occasionally flush and operate the TRT detector with an Ar-based ternary mixture, containing a small percentage of CF**4, to remove, if needed, silicon pollution from the anode wires. This procedure has been validated in realistic conditions and would require a few days of dedicated operation. This paper covers both performance and aging studies with the new TRT gas mixture. 12 Refs.

  14. Tracking properties of the ATLAS Transition Radiation Tracker (TRT)

    CERN Document Server

    Krasnopevtsev, Dimitrii; The ATLAS collaboration

    2016-01-01

    The tracking performance parameters of the ATLAS Transition Radiation Tracker (TRT) as part of the ATLAS Inner Detector (ID) are described for different data taking conditions in proton-proton collisions at the Large Hadron Collider (LHC). These studies are performed using data collected during the first (Run 1) and the second (Run 2) periods of LHC operation and are compared with Monte Carlo simulations. The performance of the TRT, operating with Xe-based (Xe-based) and Argon-based (Ar-based) gas mixtures and its dependence on the TRT occupancy is presented. No significant degradation of position measurement accuracy was found up to occupancies of about 20\\% in Run 1. The relative number of reconstructed tracks in ID that also have a extension in the TRT was observed to be almost constant with the increase of occupancies up to 50\\%. Even in configurations where tracks are close to each other, the reconstruction algorithm is still able to find the correct TRT hits and properly reconstruct the tracks.

  15. Performance of the Electromagnetic Calorimeter of AMS-02 on the International Space Station ans measurement of the positronic fraction in the 1.5 – 350 GeV energy range

    CERN Document Server

    Basara, Laurent

    The AMS-02 experiment is a particle detector installed on the International Space Station (ISS) since May 2011, which measures the characteristics of the cosmic rays to bring answers to the problematics risen by the astroparticle physics since a few decades, in particular the study of dark matter and the search of antimatter. The phenomenological aspects of the physics of cosmic rays are reviewed in a first part. A second one describes the in-flight performances of the different subdetectors of AMS-02, in particular the electromagnetic calorimeter. It is shown, using particles at the ionizing minimum (MIPs), accounting for the main part of cosmic rays, that the calorimeter works as expected, and we find the same performances as on ground. This study is used to follow in time the evolution of the detector performances. It also allows to develop a charge estimator for the nuclei using the calorimeter. A third and final part, deals with the determination of the positronic fraction. The main difficulty of this me...

  16. Transition radiation at radio frequencies from ultra-high energy neutrino-induced showers

    CERN Document Server

    Motloch, Pavel; Privitera, Paolo; Zas, Enrique

    2015-01-01

    Coherent radiation at radio frequencies from high-energy showers fully contained in a dense radio-transparent medium - like ice, salt or regolith - has been extensively investigated as a promising technique to search for ultra-high energy (UHE) neutrinos. Additional emission in the form of transition radiation may occur when a neutrino-induced shower produced close to the Earth surface emerges from the ground into atmospheric air. We present the first detailed evaluation of transition radiation from high-energy showers crossing the boundary between two different media. We found that transition radiation is sizable over a wide solid angle and coherent up to $\\sim$ 1 GHz. These properties encourage further work to evaluate the potential of a large-aperture UHE neutrino experiment based on detection of transition radiation.

  17. Coherent transition radiation diagnostic for electron bunch shape measurement at FELIX

    Science.gov (United States)

    Ding, Meisong; Weits, H. H.; Oepts, D.

    1997-02-01

    An optical autocorrelation system using coherent transition radiation has been set up to determine the electron bunch shape at FELIX. A polarisation interferometer and a 10 × 10 mm 2 pyroelectric detector are used to allow operation over a wide range of wavelength (from 30 μm to 10 mm) without strong variation in efficiency. An evacuated 15 m long overmoded waveguide is used to transport the transition radiation to the experimental area. The intensity of the transition radiation was measured and compared with our calculation. The phase-retrieval technique applied to the measured spectrum provides details of the electron bunch. The bunch shapes have been studied at different buncher phase settings. Measurements of coherent transition radiation and coherent undulator radiation are compared.

  18. Interplay of radiative and nonradiative transitions in surface hopping with radiation-molecule interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bajo, Juan José [Departamento de Química-Física I, Universidad Complutense de Madrid, 28040 Madrid (Spain); Granucci, Giovanni, E-mail: giovanni.granucci@unipi.it; Persico, Maurizio [Università di Pisa, Dipartimento di Chimica e Chimica Industriale, via Risorgimento 35, 56126 Pisa (Italy)

    2014-01-28

    We implemented a method for the treatment of field induced transitions in trajectory surface hopping simulations, in the framework of the local diabatization scheme, especially suited for on-the-fly dynamics. The method is applied to a simple one-dimensional model with an avoided crossing and compared with quantum wavepacket dynamics. The results show the importance of introducing a proper decoherence correction to surface hopping, in order to obtain meaningful results. Also the energy conservation policy of standard surface hopping must be revised: in fact, the quantum wavepacket energetics is well reproduced if energy absorption/emission is allowed for in the hops determined by radiation-molecule coupling. To our knowledge, this is the first time the issues of decoherence and energy conservation have been analyzed in depth to devise a mixed quantum-classical method for dynamics with molecule-field interactions.

  19. Construction and performance of the ALICE Transition Radiation Detector

    Energy Technology Data Exchange (ETDEWEB)

    Emschermann, David

    2010-01-20

    The Transition Radiation Detector (TRD) has been designed to identify electrons in the pion dominated background of heavy-ions collisions. As electrons do not interact strongly, they allow to probe the early phase of the interaction. As trigger on high-p{sub t} e{sup +}e{sup -} pairs within 6.5 {mu}s after collision, the TRD can initiate the readout of the Time Projection Chamber (TPC). The TRD is composed of 18 super modules arranged in a barrel geometry in the central part of the ALICE detector. It offers almost 1.2 million readout channels on a total area of close to 700 m{sup 2}. The particle detection properties of the TRD depend crucially on details in the design of the cathode pad readout plane. The design parameters of the TRD readout pad plane are introduced and analysed regarding their physical properties. The noise patterns observed in the detector can be directly linked to the static pad capacitance distribution and corrected for it. A summary is then given of the TRD services infrastructure at CERN: a 70 kW low voltage system, a 1080 channel 2.5 kV high voltage setup and the Ethernet network serving more than 600 nodes. Two beam tests were conducted at the CERN PS accelerator in 2004 and 2007 using full sized TRD chambers from series production. Details on the setups are presented with particular emphasis on the custom tailored data acquisition systems. Finally the performance of the TRD is studied, focusing on the pion rejection capability and the excellent position resolution. (orig.)

  20. Demonstration of Coherent Terahertz Transition Radiation from Relativistic Laser-Solid Interactions

    Science.gov (United States)

    Liao, Guo-Qian; Li, Yu-Tong; Zhang, Yi-Hang; Liu, Hao; Ge, Xu-Lei; Yang, Su; Wei, Wen-Qing; Yuan, Xiao-Hui; Deng, Yan-Qing; Zhu, Bao-Jun; Zhang, Zhe; Wang, Wei-Min; Sheng, Zheng-Ming; Chen, Li-Ming; Lu, Xin; Ma, Jing-Long; Wang, Xuan; Zhang, Jie

    2016-05-01

    Coherent transition radiation in the terahertz (THz) region with energies of sub-mJ/pulse has been demonstrated by relativistic laser-driven electron beams crossing the solid-vacuum boundary. Targets including mass-limited foils and layered metal-plastic targets are used to verify the radiation mechanism and characterize the radiation properties. Observations of THz emissions as a function of target parameters agree well with the formation-zone and diffraction model of transition radiation. Particle-in-cell simulations also well reproduce the observed characteristics of THz emissions. The present THz transition radiation enables not only a potential tabletop brilliant THz source, but also a novel noninvasive diagnostic for fast electron generation and transport in laser-plasma interactions.

  1. Generation of linearly polarized resonant transition radiation X-ray beam

    Energy Technology Data Exchange (ETDEWEB)

    Yajima, Kazuaki; Awata, Takaaki; Ikeda, Mitsuharu; Ikeda, Kenichi; Yogo, Akifumi; Itoh, Akio; Imanishi, Nobutsugu [Kyoto Univ. (Japan). Dept. of Nuclear Engineering

    2000-03-01

    We have proposed a method to generate almost linearly polarized resonant transition radiation X rays by using a rectangular slit placed on an electron beam axis. Our calculation predicted that the linearity is 93.5% for the resonant transition radiation X-ray beam extracted through a slit of 0.5 mrad long and 0.2 mrad wide in case of 1-GeV electron beam irradiating a 7.5-{mu}m thick Kapton foil stack. (author)

  2. Optical Transition Radiation Measurement of Electron Beam for Beijing Free Electron Laser

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qiang; XIE Jia-Lin; LI Yong-Gui; ZHUANG Jie-Jia

    2001-01-01

    We used transition radiation techniques instead of the original phosphor targets to improve the electronic beam diagnostic system at Beijing Free Electron Laser. The beam profile, size (3.3 × 2.4 mm), position and divergence angle (σrms = 2.5 mrad) in transverse have been obtained from optical transition radiation. We also present the experimental set-up and some preliminary results.

  3. Measurements of the spectrum and energy dependence of X-ray transition radiation

    Science.gov (United States)

    Cherry, M. L.

    1978-01-01

    The results of experiments designed to test the theory of X-ray transition radiation and to verify the predicted dependence of the characteristic features of the radiation on the radiator dimensions are presented. The X-ray frequency spectrum produced by 5- to 9-GeV electrons over the range 4 to 30 keV was measured with a calibrated single-crystal Bragg spectrometer, and at frequencies up to 100 keV with an NaI scintillator. The interference pattern in the spectrum and the hardening of the radiation with increasing foil thickness are clearly observed. The energy dependence of the total transition-radiation intensity was studied using a radiator with large dimensions designed to yield energy-dependent signals at very high particle energies, up to E/mc-squared approximately equal to 100,000. The results are in good agreement with the theoretical predictions.

  4. ATLAS Transition Radiation Tracker (TRT) Electronics Operation Experience at High Rates

    CERN Document Server

    Mistry, Khilesh; The ATLAS collaboration

    2015-01-01

    The ATLAS Transition Radiation Tracker (TRT) is a gaseous drift tube tracker which combines continuous tracking capabilities with particle identification based on transition radiation. The TRT Data Acquisition system uses custom front-end ASICs and boards for trigger and timing control as well as data read-out. To prepare for LHC run 2, changes were made to support the increased ATLAS trigger rate of 100 kHz, increased TRT occupancy caused by higher LHC luminosity, and gas mixture changes in some TRT straw tubes. Radiation studies were performed following an observed gain loss at the front-end during the 2012 run.

  5. Edge-core interplay in transition to radiative improved mode

    Energy Technology Data Exchange (ETDEWEB)

    Tokar, M.Z.; Unterberg, B. [Association Euratom-Forschungszentrum Juelich GmbH (Germany). Inst. fuer Plasmaphysik; Jaspers, R. [Associatie Euratom-FOM, Nieuwegein (Netherlands). FOM-Instituut voor Plasmafysica

    1998-05-01

    A new radiative improved-mode (RI-mode) has been found in TEXTOR-94 in experiments aimed to prove feasibility of the concept of a radiating plasma mantle under quasi-stationary conditions of auxiliary heated discharges. By puffing of neon, silane or argon, up to 95% of the total input power can be radiated without detachment of the plasma from the limiter. Contrary to the common belief, the high edge radiation level does not lead to a degradation of the energy confinement, but can cause a substantial improvement with an appropriate heating and operational scenario. Investigation of the mechanisms of the confinement improvement in the RI-mode by means of predictive transport modeling is the aim of this contribution. (orig.) 6 refs.

  6. Emission Angles for Soft X-Ray Coherent Transition Radiation.

    Science.gov (United States)

    1987-09-01

    School is used to study radiation effects and damage, radiation characteristics and nuclear structure. The LINAC is capable of operating from...Private communication.) 43 ........ 11. "PCD Linear Image Sensors (S3201 Series)," HAMAMATSU Technical Data Sheet, July 1985. 12. "Application of Reticon ...Photodiode Arrays as Electron and X-Ray Detectors," EG&G Reticon Application Notes No. 101, 1975. 13. Chu, A.N., M.A. Piestrup and R.H. Pantell

  7. Observation of coherent transition radiation using relativistic pico second electron pulse

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.R.; Kosai, H.; Dutt, J.M. [North Carolina Central Univ., Durham, NC (United States)

    1995-12-31

    When an electron beams passes through boundaries of two different media with different dielectric constants, it generates radiation. The radiation emitted by the prebunched electron beam becomes coherent if the size of the bunch is smaller than the wavelength. Therefore, transition radiation can be considered as a possible broad band radiation source as well as a probe to the pico second and sub picosecond electron beam profiles. Using 1.2 MeV, 200 mA, macropulse electron beam, transition radiation was generated. The electron gun consists of 2.856 GHz Klystron, thermionic cathode. The emitted electron beam was bunched by passing through an alpha magnet. As a result of the combination, a pico second pulse (1.2 MeV, up to 80 A micropulse) was obtained. Experimental results, comparisons with the theory, and simulated electron beam profiles will be presented.

  8. A transition radiation detector which features accurate tracking and dE/dx particle identification

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, E.; Lissauer, D.; McCorkle, S.; Polychronakos, V.; Takai, H. [Brookhaven National Lab., Upton, NY (United States); Chi, C.Y.; Nagamiya, S.; Sippach, W.; Toy, M.; Wang, D.; Wang, Y.F.; Wiggins, C.; Willis, W. [Columbia Univ., New York, NY (United States); Cherniatin, V.; Dolgoshein, B. [Moscow Inst. of Physics and Engineering, Moscow (Russia Federation); Bennett, M.; Chikanian, A.; Kumar, S.; Mitchell, J.T.; Pope, K. [Yale Univ., New Haven, CT (United States)

    1991-12-31

    We describe the results of a test run involving a Transition Radiation Detector that can both distinguish electrons from pions with momenta greater than 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most efficient below 2 GeV/c while particle ID utilizing Transition Radiation is effective above 1.5 GeV/c. Combined, the electron-pion separation is better than 5 {times} l0{sup 2}. The single-wire, track-position resolution for the TRD is {approximately}230{mu}m.

  9. A transition radiation detector which features accurate tracking and dE/dx particle identification

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, E.; Lissauer, D.; McCorkle, S.; Polychronakos, V.; Takai, H. (Brookhaven National Lab., Upton, NY (United States)); Chi, C.Y.; Nagamiya, S.; Sippach, W.; Toy, M.; Wang, D.; Wang, Y.F.; Wiggins, C.; Willis, W. (Columbia Univ., New York, NY (United States)); Cherniatin, V.; Dolgoshein, B. (Moscow Inst. of Physics and Engineering (Russian Federation)); Bennett, M.; Chikanian, A.; Kumar, S.; Mitchell, J.T.; Pope, K. (Yale Univ., New Haven, CT (United States))

    1993-04-01

    The authors describe the results of a test run involving a Transition Radiation Detector that can both distinguish electrons from pions with momenta greater than 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most efficient below 2 GeV/c while particle ID utilizing Transition Radiation is effective above 1.5 GeV/c. Combined, the electron-pion separation is better than 5 x 10[sup 2]. The single-wire, track-position resolution for the TRD is [approximately] [mu]m.

  10. A transition radiation detector for RHIC featuring accurate tracking and dE/dx particle identification

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, E.; Lissauer, D.; McCorkle, S.; Polychronakos, V.; Takai, H. [Brookhaven National Lab., Upton, NY (United States); Chi, C.Y.; Nagamiya, S.; Sippach, W.; Toy, M.; Wang, D.; Wang, Y.F.; Wiggins, C.; Willis, W. [Columbia Univ., New York, NY (United States); Cherniatin, V.; Dolgoshein, B. [Moscow Institute of Physics and Engineering, (Russian Federation); Bennett, M.; Chikanian, A.; Kumar, S.; Mitchell, J.T.; Pope, K. [Yale Univ., New Haven, CT (United States)

    1991-12-31

    We describe the results of a test ran involving a Transition Radiation Detector that can both distinguish electrons from pions which momenta greater titan 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most, efficient below 2 GeV/c while particle ID utilizing Transition Radiation effective above 1.5 GeV/c. Combined, the electron-pion separation is-better than 5 {times} 10{sup 2}. The single-wire, track-position resolution for the TRD is {approximately}230 {mu}m.

  11. Measurement of Sub-Picosecond Electron Bunches via Electro-Optic Sampling of Coherent Transition Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Timothy John [Northern Illinois U.

    2012-01-01

    Future collider applications as well as present high-gradient laser plasma wakefield accelerators and free-electron lasers operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation or the bunch wakefields with sub-picosecond time resolution. We present results on the single-shot electro-optic spectral decoding of coherent transition radiation from bunches generated at the Fermilab A0 photoinjector laboratory. A longitudinal double-pulse modulation of the electron beam is also realized by transverse beam masking followed by a transverse-to-longitudinal phase-space exchange beamline. Live profile tuning is demonstrated by upstream beam focusing in conjunction with downstream monitoring of single-shot electro-optic spectral decoding of the coherent transition radiation.

  12. Predictors of Psychosocial Adjustment During the Post-Radiation Treatment Transition

    OpenAIRE

    Mazanec, Susan; Daly, Barbara J.; Douglas, Sara; Musil, Carol

    2010-01-01

    The aim of this study was to examine the role of cognitive appraisal in predicting psychosocial adjustment during the post-radiation treatment transition. A predictive correlational design was used in a convenience sample of 80 patients with breast, lung, and prostate cancer who were receiving radiation therapy. Two weeks prior to completion of treatment, subjects completed instruments to measure symptom distress, uncertainty, cognitive appraisal, social support and self-efficacy for coping. ...

  13. Formation region effects in transition radiation, bremsstrahlung, and ionization loss of ultrarelativistic electrons

    Science.gov (United States)

    Trofymenko, S. V.; Shul'ga, N. F.

    2016-11-01

    The processes of transition radiation and bremsstrahlung by an ultrarelativistic electron as well as the effect of transition radiation influence upon the electron ionization loss in thin layer of substance are theoretically investigated in the case when radiation formation region has macroscopically large size. Special attention is drawn to transition radiation (TR) generated during the traversal of thin metallic plate by the electron previously deflected from its initial direction of motion. In this case TR characteristics are calculated for realistic (circular) shape of the electron deflection trajectory. The difference of such characteristics under certain conditions from the ones obtained previously with the use of approximation of anglelike shape of the electron trajectory (instant deflection) is shown. The problem of measurement of bremsstrahlung characteristics in the prewave zone is investigated. The expressions defining the measured radiation distribution for arbitrary values of the size and the position of the detector used for radiation registration are derived. The problem of TR influence upon the electron ionization loss in thin plate and in a system of two plates is discussed. The proposal for experimental investigation of such effect is formulated.

  14. Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Ullaland, O

    2011-01-01

    Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors in 'Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors 3.3.1 Introduction 3.3.2 Time of Flight Measurements 3.3.2.1 Scintillator hodoscopes 3.3.2.2 Parallel plate ToF detectors 3.3.3 Cherenkov Radiation 3.3.3.1 ...

  15. Phenomenology of heavy quarkonium radiative E1 transitions

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Hector E. [Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany)

    2016-01-22

    We present preliminary results of the evaluation of the next-to-leading-order (NLO) relativistic corrections to the heavy quarkonium electric dipole transition (E1) rate. In our evaluation we use the quark-antiquark potential up to 1/m{sup 2} corrections that includes the effective string theory expression for the long range, a review on the method to construct this potential is given. Our results compare favorable with the experiments and may provide predictions for the rates for which no experimental data is yet available.

  16. Report on the Radiation Effects Testing of the Infrared and Optical Transition Radiation Camera Systems

    Energy Technology Data Exchange (ETDEWEB)

    Holloway, Michael Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-20

    Presented in this report are the results tests performed at Argonne National Lab in collaboration with Los Alamos National Lab to assess the reliability of the critical 99Mo production facility beam monitoring diagnostics. The main components of the beam monitoring systems are two cameras that will be exposed to radiation during accelerator operation. The purpose of this test is to assess the reliability of the cameras and related optical components when exposed to operational radiation levels. Both X-ray and neutron radiation could potentially damage camera electronics as well as the optical components such as lenses and windows. This report covers results of the testing of component reliability when exposed to X-ray radiation. With the information from this study we provide recommendations for implementing protective measures for the camera systems in order to minimize the occurrence of radiation-induced failure within a ten month production run cycle.

  17. Terahertz coherent transition radiation based on an ultrashort electron bunching beam

    Science.gov (United States)

    Liu, Wen-Xin; Huang, Wen-Hui; Du, Ying-Chao; Yan, Li-Xin; Wu, Dai; Tang, Chuan-Xiang

    2011-07-01

    The experimental result of terahertz (THz) coherent transition radiation generated from an ultrashort electron bunching beam is reported. During this experiment, the window for THz transmission from ultrahigh vacuum to free air is tested. The compact measurement system which can simultaneously test the THz wave power and frequency is built and proofed. With the help of improved Martin—Puplett interferometer and Kramers—Krong transform, the longitudinal bunch length is measured. The results show that the peak power of THz radiation wave is more than 80 kW, and its radiation frequency is from 0.1 THz to 1.5 THz.

  18. Coherent transition radiation diagnostic for electron bunch shape measurement at FELIX

    NARCIS (Netherlands)

    Ding, M. S.; Weits, H. H.; Oepts, D.

    1997-01-01

    An optical autocorrelation system using coherent transition radiation has been set up to determine the electron bunch shape at FELIX. A polarisation interferometer and a 10 x 10 mm(2) pyroelectric detector are used to allow operation over a wide range of wavelength (from 30 mu m to 10 mm) without st

  19. Modelling of Noise and Straw to Straw Variations in the ATLAS Transition Radiation Tracker

    CERN Document Server

    Kittelmann, T H

    2006-01-01

    In this note a procedure is presented for modelling noise and straw to straw variations in the ATLAS Transition Radiation Tracker which can ultimately be based on reliable off-beam occupancy maps. The model is tuned and validated against the results of a test beam study, and its implementation in offline digitisation software is discussed.

  20. Longitudinal electron bunch diagnostics using coherent transition radiation at the IRFEL

    Science.gov (United States)

    Zhou, T. Y.; Yang, Y. L.; Sun, B. G.; Tang, L. L.; Lu, P.; Zhou, Z. R.; Wu, F. F.; Liu, X. Y.

    2016-09-01

    A longitudinal electron bunch diagnostics system is developing to measure the longitudinal bunch charge distribution for the new IRFEL at National Synchrotron Radiation Laboratory (NSRL). We use a Martin-Puplett interferometer, which is essentially a Michelson interferometer, to measure the spectrum of the coherent transition radiation produced by electrons through a thin metallic foil. Frequency components of coherent transition radiation have a relationship with the bunch form factor, which is described by the square modulus of the Fourier transform of the bunch distribution. Then several techniques, including a Kramers-Kronig analysis, have been applied to determine the longitudinal bunch charge distribution. The details of the design and theoretical investigation will be described in this paper.

  1. Multilevel radiative thermal memory realized by the hysteretic metal-insulator transition of vanadium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kota, E-mail: kotaito@mosk.tytlabs.co.jp; Nishikawa, Kazutaka; Iizuka, Hideo [Toyota Central Research and Development Labs, Nagakute, Aichi 480-1192 (Japan)

    2016-02-01

    Thermal information processing is attracting much interest as an analog of electronic computing. We experimentally demonstrated a radiative thermal memory utilizing a phase change material. The hysteretic metal-insulator transition of vanadium dioxide (VO{sub 2}) allows us to obtain a multilevel memory. We developed a Preisach model to explain the hysteretic radiative heat transfer between a VO{sub 2} film and a fused quartz substrate. The transient response of our memory predicted by the Preisach model agrees well with the measured response. Our multilevel thermal memory paves the way for thermal information processing as well as contactless thermal management.

  2. Search for Detour Transitions in the Radiative EC Decay of $^{81}$Kr

    CERN Multimedia

    Rykaczewski, K

    2002-01-01

    % IS355 \\\\ \\\\ It is proposed to produce at ISOLDE the $^{81}$Kr activity and to study its 1-st forbidden unique (1u) radiative electron-capture decay in low background conditions available in Warsaw. The intensity of the photon spectrum will be compared to predictions of the internal-bremsstrahlung theory. A question is whether an excess of the intensity will be observed, indicating the role of detour $\\gamma$/$\\beta$ transitions via intermediate virtual nuclear states, as detected already for the 1u radiative decay of $^{41}$Ca.

  3. Radiative transitions in charm-strange meson from Nf = 2 twisted mass lattice QCD

    Science.gov (United States)

    Li, Ning; Wu, Ya-Jie

    2016-07-01

    We present an exploratory study on the radiative transition for the charm-strange meson: Ds∗→ D sγ using Nf = 2 twisted mass lattice quantum chromodynamics gauge configurations. The form factor for Ds meson is also determined. The simulation is performed on lattices with lattice spacings a = 0.067 fm and lattice size 323 × 64, and a = 0.085 fm and lattice size 243 × 48, respectively. Our numerical results for radiative decay width and the experimental data overlap within the margin of error.

  4. Single-shot electro-optic sampling of coherent transition radiation at the A0 Photoinjector

    CERN Document Server

    Maxwell, T J; Piot, P; Thurman-Keup, R

    2012-01-01

    Future collider applications and present high-gradient laser plasma wakefield accelerators operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation or the bunch wakefields with sub-picosecond time resolution. Potential applications in shot-to-shot, non-interceptive diagnostics continue to be pursued for live beam monitoring of collider and pump-probe experiments. Related to our developing work with electro-optic imaging, we present results on single-shot electro-optic sampling of the coherent transition radiation from bunches generated at the A0 photoinjector.

  5. A Novel Highly Ionizing Particle Trigger using the ATLAS Transition Radiation Tracker

    CERN Document Server

    Penwell, J; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker (TRT) is an important part of the experiment’s charged particle tracking system. It also provides the ability to discriminate electrons from pions efficiently using large signal amplitudes induced in the TRT straw tubes by transition radiation. This amplitude information can also be used to identify heavily ionizing particles, such as monopoles, or Q-balls, that traverse the straws. Because of their large ionization losses, these particles can range out before they reach the ATLAS calorimeter, making them difficult to identify by the experiment’s first level trigger. Much of this inefficiency could be regained by making use of a feature of the TRT electronics that allows fast access to information on whether large-amplitude signals were produced in regions of the detector. A modest upgrade to existing electronics could allow triggers sensitive to heavily ionizing particles at level-1 to be constructed by counting such large-amplitude signals in roads corresponding to...

  6. Recombination of charge carriers on radiation-induced defects in silicon doped by transition metals impurities

    CERN Document Server

    Kazakevich, L A

    2003-01-01

    It has been studied the peculiarities of recombination of nonequilibrium charge carriers on radiation-induced defects in received according to Czochralski method p-silicon (p approx 3 - 20 Ohm centre dot cm), doped by one of the impurities of transition metals of the IV-th group of periodic table (titanium, zirconium, hafnium). Experimental results are obtained out of the analysis of temperature and injection dependence of the life time of charge carriers. The results are explained taking into consideration the influences of elastic stress fields created by the aggregates of transition metals atoms on space distribution over the crystal of oxygen and carbon background impurities as well as on the migration of movable radiation-induced defects during irradiation. (authors).

  7. Operation of the ATLAS Transition Radiation Tracker under very high irradiation at the CERN LHC

    CERN Document Server

    Åkesson, T; Baker, K; Baron, S; Benjamin, D; Bertelsen, H; Bondarenko, V; Bychkov, V; Callahan, J; Capéans-Garrido, M; Cardiel-Sas, L; Catinaccio, A; Cetin, S A; Cwetanski, Peter; Dam, M; Danielsson, H; Dittus, F; Dolgoshein, B A; Dressnandt, N; Driouichi, C; Ebenstein, W L; Eerola, Paule Anna Mari; Farthouat, Philippe; Fedin, O; Froidevaux, D; Gagnon, P; Grichkevitch, Y; Grigalashvili, N S; Hajduk, Z; Hansen, P; Kayumov, F; Keener, P T; Kekelidze, G D; Khristatchev, A; Konovalov, S; Koudine, L; Kovalenko, S; Kowalski, T; Kramarenko, V A; Krüger, K; Laritchev, A; Lichard, P; Luehring, F C; Lundberg, B; Maleev, V; McFarlane, K W; Mialkovski, V; Mindur, B; Mitsou, V A; Morozov, S; Munar, A; Muraviev, S; Nadtochy, A; Newcomer, F M; Ögren, H O; Oleshko, S; Olszowska, J; Passmore, S; Patritchev, S; Peshekhonov, V D; Petti, R; Price, M; Rembser, C; Rohne, O; Romaniouk, A; Rust, D R; Ryabov, Yu; Shchegelskii, V; Seliverstov, D M; Shin, T; Shmeleva, A; Smirnov, S; Sosnovtsev, V V; Soutchkov, V; Spiridenkov, E; Tikhomirov, V; Van Berg, R; Vassilakopoulos, V I; Vassilieva, L; Wang, C; Williams, H H; Zalite, A

    2004-01-01

    The ATLAS Transition Radiation Tracker (TRT) performance depends critically on the choice of the active gas and on its properties. The most important operational aspects, which have led to the final choice of the active gas for the operation of the TRT at the LHC design luminosity, are presented. The TRT performance expected at these conditions is reviewed, including pile-up effects at high luminosity. (9 refs).

  8. Determination of electron bunch shape using transition radiation and phase-energy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Crosson, E.R.; Berryman, K.W.; Richman, B.A. [Stanford Univ., CA (United States)] [and others

    1995-12-31

    We present data comparing microbunch temporal information obtained from electron beam phase-energy measurements with that obtained from transition radiation auto-correlation measurements. The data was taken to resolve some of the ambiguities in previous transition radiation results. By measuring the energy spectrum of the electron beam as a function of its phase relative to the accelerating field, phase-energy information was extracted. This data was analyzed using tomographic techniques to reconstruct the phase-space distribution assuming an electron energy dependence of E({var_phi}) = E{sub o} + E{sub acc}cos({var_phi}), where E{sub o} is the energy of an electron entering the field, E{sub acc} is the peak energy gain, and {var_phi} is the phase between the crest of the RF wave and an electron. Temporal information about the beam was obtained from the phase space distribution by taking the one dimensional projection along the time axis. We discuss the use of this technique to verify other transition radiation analysis methods.

  9. ORAL ISSUE OF THE JOURNAL "USPEKHI FIZICHESKIKH NAUK": Transition radiation: scientific implications and applications in high-energy physics

    Science.gov (United States)

    Denisov, Sergei P.

    2007-04-01

    In their pioneering work on transition radiation, Ginzburg and Frank showed for the first time that a charge may radiate electromagnetic waves not only because of its accelerated motion but also because of time variation of the phase velocity of electromagnetic waves in the ambient medium. This result is of very general importance for physics. For example, a charge at rest can radiate in a nonstationary medium. Transition radiation is widely used in high-energy particle detectors, mainly for identification of ultrarelativistic electrons in accelerator and collider experiments.

  10. The effects of radiative and microphysical processes on simulated warm and transition season arctic stratus

    Science.gov (United States)

    Harrington, Jerry Y.

    A cloud-resolving model (CRM) version of RAMS, coupled to explicit bin resolving microphysics and a new two-stream radiative transfer code is used to study various aspects of Arctic stratus clouds (ASC). The two-stream radiative transfer model is coupled in a consistent fashion to the bulk microphysical parameterization of Walko et al., (1995), an explicit liquid bin microphysical model (e.g., Feingold et al., 1996a) and a mixed-phase microphysical model (Reisin et al., 1996). These models are used to study both warm (summer) season and transition (fall and spring) season ASC. Equations are developed for the inclusion of the radiative term in the drop growth equation and the effect is studied in a trajectory parcel model (TPM) and the CRM. Arctic stratus simulated with the new CRM framework compared well with the observations of Curry (1986). Along with CCN concentrations, it is shown that drop distribution shape and optical property methods strongly impact cloud evolution through their effect on the radiative properties. Broader cloud top distributions lead to clouds with more shallow depths and circulation strengths as more shortwave radiation is absorbed while the opposite occurs for narrow distribution functions. Radiative-cloud interactions using mean effective radii are shown to be problematic, while conserving re and N of the distribution function (as per Hu and Stamnes, 1993) produces similar cloud evolution as compared to detailed computations. Radiative effects on drop vapor deposition growth can produce drizzle about 30 minutes earlier and is strongly dependent upon cloud top residence time of the parcels. The same set of trajectories assists drizzle production in the radiation and no-radiation cases. Not only is the growth of larger drops enhanced by the radiative effect, but drops with r<10/mu m are caused to evaporate; the effects together constitute a method of spectral broadening at cloud top. Simulations with the CRM show a smaller impact of the

  11. Coherent regime and far-to-near-field transition for radiative heat transfer

    Science.gov (United States)

    Tsurimaki, Yoichiro; Chapuis, Pierre-Olivier; Okajima, Junnosuke; Komiya, Atsuki; Maruyama, Shigenao; Vaillon, Rodolphe

    2017-01-01

    Radiative heat transfer between two semi-infinite parallel media is analyzed in the transition zone between the near-field and the classical macroscopic, i.e. incoherent far-field, regimes of thermal radiation, first for model gray materials and then for real metallic (Al) and dielectric (SiC) materials. The presence of a minimum in the flux-distance curve is observed for the propagative component of the radiative heat transfer coefficient, and in some cases for the total coefficient, i.e. the sum of the propagative and evanescent components. At best this reduction can reach 15% below the far-field limit in the case of aluminum. The far-to-near-field regime taking place for the distance range between the near-field and the classical macroscopic regime involves a coherent far-field regime. One of its limits can be practically defined by the distance at which the incoherent far-field regime breaks down. This separation distance below which the standard theory of incoherent thermal radiation cannot be applied anymore is found to be larger than the usual estimate based on Wien's law and varies as a function of temperature. The aforementioned effects are due to coherence, which is present despite the broadband spectral nature of thermal radiation, and has a stronger impact for reflective materials.

  12. Radiative transitions in InGaN quantum-well structures

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Noad Asaf [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    InGaN based light emitting devices demonstrate excellent luminescence properties and have great potential in lighting applications. Though these devices are already being produced on an industrial scale, the nature of their radiative transition is still not well understood. In particular, the role of the huge (>1MV/cm), built-in electric field in these transitions is still under debate. The luminescence characteristics of InGaN quantum well structures were investigated as a function of excitation power, temperature, and biaxial strain, with an intent of discerning the effects of the electric field and inhomogeneous indium distribution in the QW on the radiative transition. It was found that the luminescence energy did not scale only with the indium concentration but that the QW thickness must also be taken into account. The thickness affects the transition energy due to quantum confinement and carrier separation across a potential drop in the QW. The luminescence peak width was shown to increase with increased indium fraction, due to increased indium inhomogeneity. The carrier lifetime increased exponentially with QW thickness and luminescence wavelength, due to increased carrier separation. Measuring the luminescence energy and carrier lifetime as a function of excitation density showed that the electric field can be screened by strong excitation and, as a consequence, the carrier separation reduced. The temperature dependence of the luminescence showed evidence for bandtails in the density of states, a phenomenon that has been previously related to transition in indium-rich nano-clusters, yet could be accounted for by fluctuations in other parameters that affect the transition energy. Room temperature luminescence efficiency was shown to weakly decrease with increased QW thickness. The application of biaxial strain resulted in either a redshift or blueshift of the luminescence, depending on the sample. The direction and magnitude of the shift in luminescence

  13. Radiative transitions in InGaN quantum-well structures

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Noad Asaf

    2002-06-27

    InGaN based light emitting devices demonstrate excellent luminescence properties and have great potential in lighting applications. Though these devices are already being produced on an industrial scale, the nature of their radiative transition is still not well understood. In particular, the role of the huge (>1MV/cm), built-in electric field in these transitions is still under debate. The luminescence characteristics of InGaN quantum well structures were investigated as a function of excitation power, temperature, and biaxial strain, with an intent of discerning the effects of the electric field and inhomogeneous indium distribution in the QW on the radiative transition. It was found that the luminescence energy did not scale only with the indium concentration but that the QW thickness must also be taken into account. The thickness affects the transition energy due to quantum confinement and carrier separation across a potential drop in the QW. The luminescence peak width was shown to increase with increased indium fraction, due to increased indium inhomogeneity. The carrier lifetime increased exponentially with QW thickness and luminescence wavelength, due to increased carrier separation. Measuring the luminescence energy and carrier lifetime as a function of excitation density showed that the electric field can be screened by strong excitation and, as a consequence, the carrier separation reduced. The temperature dependence of the luminescence showed evidence for bandtails in the density of states, a phenomenon that has been previously related to transition in indium-rich nano-clusters, yet could be accounted for by fluctuations in other parameters that affect the transition energy. Room temperature luminescence efficiency was shown to weakly decrease with increased QW thickness. The application of biaxial strain resulted in either a redshift or blueshift of the luminescence, depending on the sample. The direction and magnitude of the shift in luminescence

  14. Transition radiation detectors for electron identification beyond 1 GeV/ c

    Science.gov (United States)

    Appuhn, R. D.; Heinloth, K.; Lange, E.; Oedingen, R.; Schlösser, A.

    1988-01-01

    Transition radiation detectors (TRDs) have been tested for the separation of electrons from pions in the momentum range between 1 and 6 GeV/ c. Foams as well as fibres and foils served as radiator materials while two types of chambers, a longitudinal drift chamber (DC) and a multiwire proportional chamber (MWPC), both of 16 mm depth and dominantly filled with xenon, were used for detecting the transition radiation photons with a setup of four chambers. Analyzing the data we compared the methods of mean, truncated mean and of maximum likelihood of the total charge measurements and several methods of cluster analysis. As a result of the total charge measurements performed at test beams at CERN and DESY we obtained about 1% pion contamination at 90% electron efficiency for the polypropylene materials in the configuration of four modules with a total length of 40 cm. An improvement by a factor of about two for the electron/pion discrimination can be obtained in the case of a detailed analysis of the clusters.

  15. A study of the radiative transition $\\pi \\pi \\to \\pi \\gamma^{*}$ with lattice QCD

    CERN Document Server

    Leskovec, Luka; Koutsou, Giannis; Meinel, Stefan; Negele, John W; Paul, Srijit; Petschlies, Marcus; Pochinsky, Andrew; Rendon, Gumaro; Syritsyn, Sergey

    2016-01-01

    Lattice QCD calculations of radiative transitions between hadrons have in the past been limited to processes of hadrons stable under the strong interaction. Recently developed methods for $1\\to2$ transition matrix elements in a finite volume now enable the determination of radiative decay rates of strongly unstable particles. Our lattice QCD study focuses on the process $\\pi \\pi \\to \\pi \\gamma^{*}$, where the $\\rho$ meson is present as an enhancement in the cross-section. We use $2+1$ flavors of clover fermions at a pion mass of approximately $320$ MeV and a lattice size of approximately $3.6$ fm. The required $2$-point and $3$-point correlation functions are constructed from a set of forward, sequential and stochastic light quark propagators. In addition to determining the $\\rho$ meson resonance parameters via the L\\"uscher method, the scattering phase shift is used in conjunction with the $1\\to2$ transition matrix element formalism of Brice\\~no, Hansen and Walker-Loud to compute the $\\pi\\pi\\to\\pi\\gamma^{*}$...

  16. Interaction of a moving charged particle with a spatially dispersive medium. II. Čerenkov and transition radiation

    NARCIS (Netherlands)

    Hoenders, B.J.; Pattanayak, D.N.

    1976-01-01

    In the preceding paper, we obtained expressions for the electromagnetic field generated by the interaction of a uniformly moving electron with a spatially dispersive half-space. One part of the field was identified with Čerenkov radiation and the other part with transition radiation. In this paper i

  17. Performance of the transition radiation detector of the PAMELA space mission

    CERN Document Server

    Ambriola, M

    2002-01-01

    The performance of the transition radiation detector (TRD) of the PAMELA telescope has been studied using beam test data and simulation tools. PAMELA is a satellite-borne magnetic spectrometer designed to measure particles and antiparticles spectra in cosmic rays. The particle identification at high energy will be achieved by combining the measurements by the TRD and a Si-W imaging calorimeter. The TRD is composed of 9 planes of straw tubes, interleaved with carbon fiber radiators. A prototype of the detector has been exposed to particle beams of electrons, pions and muons of various momenta at the CERN-PS and SPS accelerator facilities. In addition a dedicated Monte Carlo code has been developed to simulate the detector. Here we illustrate both simulation results and experimental data analysis procedures and we will discuss the estimated TRD performance. (15 refs).

  18. Observation of coherently enhanced tunable narrow-band terahertz transition radiation from a relativistic sub-picosecond electron bunch train

    Energy Technology Data Exchange (ETDEWEB)

    Piot, P. [Northern Illinois Univ., DeKalb, IL (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Sun, Y. -E [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Maxwell, T. J. [Northern Illinois Univ., DeKalb, IL (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Ruan, J. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Lumpkin, A. H. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Rihaoui, M. M. [Northern Illinois Univ., DeKalb, IL (United States); Thurman-Keup, R. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2011-06-27

    We experimentally demonstrate the production of narrow-band (δf/f ~ =20% at f ~ = 0.5 THz) THz transition radiation with tunable frequency over [0.37, 0.86] THz. The radiation is produced as a train of sub-picosecond relativistic electron bunches transits at the vacuum-aluminum interface of an aluminum converter screen. In addition, we show a possible application of modulated beams to extend the dynamical range of a popular bunch length diagnostic technique based on the spectral analysis of coherent radiation.

  19. A novel method for sub-micrometer transverse electron beam size measurements using optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Aryshev, A; Boogert, S T; Karataev, P [John Adams Institute at Royal Holloway, Egham, Surrey, TW20 0EX (United Kingdom); Howell, D [John Adams Institute at Oxford University, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Terunuma, N; Urakawa, J, E-mail: alar@post.kek.j [KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2010-06-01

    Optical Transition Radiation (OTR) appearing when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in various facilities worldwide. The resolution of the monitor is defined by so-called Point Spread Function (PSF), source distribution generated by a single electron and projected by an optical system onto a screen. In this paper we represent the development of a novel sub-micrometre electron beam profile monitor based on the measurements of the PSF structure. The first experimental results are presented and future plans on the optimization of the monitor are discussed

  20. Modelling radiation emission in the transition from the classical to the quantum regime

    CERN Document Server

    Martins, J L; Grismayer, T; Vieira, J; Fonseca, R A; Silva, L O

    2015-01-01

    An emissivity formula is derived using the generalised Fermi-Weizacker-Williams method of virtual photons which accounts for the recoil the charged particle experiences as it emits radiation. It is found that through this derivation the formula obtained by Sokolov et al using QED perturbation theory is recovered. The corrected emissivity formula is applied to nonlinear Thomson scattering scenarios in the transition from the classical to the quantum regime, for small values of the nonlinear quantum parameter \\chi. Good agreement is found between this method and a QED probabilistic approach for scenarios where both are valid. In addition, signatures of the quantum corrections are identified and explored.

  1. Transverse beam shape measurements of intense proton beams using optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Scarpine, Victor E.; /Fermilab

    2012-03-01

    A number of particle physics experiments are being proposed as part of the Department of Energy HEP Intensity Frontier. Many of these experiments will utilize megawatt level proton beams onto targets to form secondary beams of muons, kaons and neutrinos. These experiments require transverse size measurements of the incident proton beam onto target for each beam spill. Because of the high power levels, most beam intercepting profiling techniques will not work at full beam intensity. The possibility of utilizing optical transition radiation (OTR) for high intensity proton beam profiling is discussed. In addition, previous measurements of OTR beam profiles from the NuMI beamline are presented.

  2. High-energy cosmic-ray electrons - A new measurement using transition-radiation detectors

    Science.gov (United States)

    Hartmann, G.; Mueller, D.; Prince, T.

    1977-01-01

    A new detector for cosmic-ray electrons, consisting of a combination of a transition-radiation detector and a shower detector, has been constructed, calibrated at accelerator beams, and exposed in a balloon flight under 5 g/sq cm of atmosphere. The design of this instrument and the methods of data analysis are described. Preliminary results in the energy range 9-300 GeV are presented. The energy spectrum of electrons is found to be significantly steeper than that of protons, consistent with a long escape lifetime of cosmic rays in the galaxy.

  3. Electron Beam Spectrum Diagnostics with Optical Transition Radiation on the Beijing Free-Electron Laser

    Institute of Scientific and Technical Information of China (English)

    李泉凤; 吴频; 高建江; 吴刚

    2004-01-01

    A measurement system was developed to measure the electron beam spectrum of the Beijing free-electron laser based on the optical transition radiation (OTR). This paper describes the system, which consists of a 32-channel high resolution of 0.02% OTR detector, especially the spectrometer. The OTR angular-distribution pattern at the focal plane has two apexes, but the two apexes are smoothed out due to the electron beam energy distribution. The energy spectrum can be measured if the magnet energy resolution is higher than 0.7% to distinguish the electron beam energy distribution.

  4. Effects of transverse electron beam size on transition radiation angular distribution

    Energy Technology Data Exchange (ETDEWEB)

    Chiadroni, E., E-mail: enrica.chiadroni@lnf.infn.it [Laboratori Nazionali di Frascati-INFN, via E. Fermi, 40, 00044 Frascati (Italy); Castellano, M. [Laboratori Nazionali di Frascati-INFN, via E. Fermi, 40, 00044 Frascati (Italy); Cianchi, A. [University of Rome ' Tor Vergata' and INFN-Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Honkavaara, K.; Kube, G. [Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22607 Hamburg (Germany)

    2012-05-01

    In this paper we consider the effect of the transverse electron beam size on the Optical Transition Radiation (OTR) angular distribution in case of both incoherent and coherent emission. Our results confute the theoretical argumentations presented first in Optics Communications 211, 109 (2002), which predicts a dependence of the incoherent OTR angular distribution on the beam size and emission wavelength. We present here theoretical and experimental data not only to validate the well-established Ginzburg-Frank theory, but also to show the impact of the transverse beam size in case of coherent emission.

  5. Energy levels, radiative rates and electron impact excitation rates for transitions in Si III

    CERN Document Server

    Aggarwal, K M

    2016-01-01

    Energy levels and radiative rates (A-values) for four types of transitions (E1, E2, M1, and M2) are reported for an astrophysically important Mg-like ion Si~III, whose emission lines have been observed in a variety of plasmas. For the calculations, well-known and widely-used GRASP code has been adopted, and results are listed for transitions among the 141 levels of the 3$\\ell3\\ell'$ and 3$\\ell$4$\\ell$ configurations. Experimental energies are available for only the lowest 58 levels but there is no major discrepancy with theoretical results. Similarly, the A-values and lifetimes show a satisfactory agreement with other available results, particularly for strong E1 transitions. Collision strengths are also calculated, with the DARC code, and listed for resonance transitions over a wide energy range, up to 30~Ryd. No similar results are available in the literature for comparisons. However, comparisons are made with the more important parameter, effective collision strength ($\\Upsilon$), for which recent $R$-matr...

  6. Transitional regimes of natural convection in a differentially heated cubical cavity under the effects of wall and molecular gas radiation

    Science.gov (United States)

    Soucasse, L.; Rivière, Ph.; Soufiani, A.; Xin, S.; Le Quéré, P.

    2014-02-01

    The transition to unsteadiness and the dynamics of weakly turbulent natural convection, coupled to wall or gas radiation in a differentially heated cubical cavity with adiabatic lateral walls, are studied numerically. The working fluid is air with small contents of water vapor and carbon dioxide whose infrared spectral radiative properties are modelled by the absorption distribution function model. A pseudo spectral Chebyshev collocation method is used to solve the flow field equations and is coupled to a direct ray tracing method for radiation transport. Flow structures are identified by means of either the proper orthogonal decomposition or the dynamic mode decomposition methods. We first retrieve the classical mechanism of transition to unsteadiness without radiation, characterized by counter-rotating streamwise-oriented vortices generated at the exit of the vertical boundary layers. Wall radiation through a transparent medium leads to a homogenization of lateral wall temperatures and the resulting transition mechanism is similar to that obtained with perfectly conducting lateral walls. The transition is due to an unstable stratification upstream the vertical boundary layers and is characterized by periodically oscillating transverse rolls of axis perpendicular to the main flow. When molecular gas radiation is accounted for, no periodic solution is found and the transition to unsteadiness displays complex structures with chimneys-like rolls whose axes are again parallel to the main flow. The origin of this instability is probably due to centrifugal forces, as suggested previously for the case without radiation. Above the transition to unsteadiness, at Ra = 3 × 108, it is shown that both wall and gas radiation significantly intensify turbulent fluctuations, decrease the thermal stratification in the core of the cavity, and increase the global circulation.

  7. The role of transition radiation in cathodoluminescence imaging and spectroscopy of thin-foils

    Energy Technology Data Exchange (ETDEWEB)

    Mendis, B.G. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Howkins, A. [Experimental Techniques Centre, Brunel University, Uxbridge UB8 3PH (United Kingdom); Stowe, D. [Gatan UK, 25 Nuffield Way, Abingdon, Oxfordshire OX14 1RL (United Kingdom); Major, J.D.; Durose, K. [Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZF (United Kingdom)

    2016-08-15

    There is renewed interest in cathodoluminescence (CL) in the transmission electron microscope, since it can be combined with low energy loss spectroscopy measurements and can also be used to probe defects, such as grain boundaries and dislocations, at high spatial resolution. Transition radiation (TR), which is emitted when the incident electron crosses the vacuum-specimen interface, is however an important artefact that has received very little attention. The importance of TR is demonstrated on a wedge shaped CdTe specimen of varying thickness. For small specimen thicknesses (<250 nm) grain boundaries are not visible in the panchromatic CL image. Grain boundary contrast is produced by electron–hole recombination within the foil, and a large fraction of that light is lost to multiple-beam interference, so that thicker specimens are required before the grain boundary signal is above the TR background. This is undesirable for high spatial resolution. Furthermore, the CL spectrum contains additional features due to TR which are not part of the ‘bulk’ specimen. Strategies to minimise the effects of TR are also discussed. - Highlights: • Grain boundary cathodoluminescence contrast is anomalously low in the TEM. • This is due to transition radiation (TR) generated at the vacuum-specimen interface. • Thick foils are required for the recombination luminescence to suppress TR. • This is undesirable for high spatial resolution analysis of grain boundaries. • Strategies to minimise TR are also discussed.

  8. ATLAS Transition Radiation Tracker (TRT): Straw Tube Gaseous Detectors at High Rates

    CERN Document Server

    Vogel, A; The ATLAS collaboration

    2013-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three tracking subsystems of the ATLAS Inner Detector. The ATLAS detector is located at LHC/CERN. We report on how these gaseous detectors (“straw tubes”) are performing during the ATLAS 2011 and 2012 runs where the TRT experiences higher rates than previously encountered. The TRT contains ~300000 thin-walled proportional-mode drift tubes providing on average 30 two-dimensional space points with ~130 µm resolution for charged particle tracks with |η| 0.5 GeV. Along with continuous tracking, the TRT provides electron identification capability through the detection of transition radiation X-ray photons. During the ATLAS 2012 proton-proton data runs, the TRT is operating successfully while being subjected to the highest rates of incident particles ever experienced by a large scale gaseous tracking system. In the second half of 2012, the TRT has collected data in an environment with instantaneous proton-proton luminosity of ~0.8 × 10³�...

  9. ATLAS Transition Radiation Tracker (TRT): Straw Tube Gaseous Detectors at High Rates

    CERN Document Server

    Vogel, A; The ATLAS collaboration

    2013-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three tracking subsystems of the ATLAS Inner Detector. The ATLAS detector is located at LHC/CERN. We report on how these gaseous detectors (“straw tubes”) are performing during the ATLAS 2011 and 2012 runs where the TRT experiences higher rates than previously encountered. The TRT contains ~300000 thin-walled proportional-mode drift tubes providing on average 30 two-dimensional space points with ~130 µm resolution for charged particle tracks with |η|  0.5 GeV. Along with continuous tracking, the TRT provides electron identification capability through the detection of transition radiation X-ray photons. During the ATLAS 2012 proton-proton data runs, the TRT is operating successfully while being subjected to the highest rates of incident particles ever experienced by a large scale gaseous tracking system. As of the submission date of this abstract, the TRT has collected data in an environment with instantaneous proton-proton luminosi...

  10. Straw Performance Studies and Quality Assurance for the ATLAS Transition Radiation Tracker

    CERN Document Server

    Cwetanski, Peter; Orava, Risto

    2006-01-01

    The Transition Radiation Tracker (TRT) of the ATLAS experiment at the LHC is part of the Inner Detector. It is designed as a robust and powerful gaseous detector that provides tracking through individual drift-tubes (straws) as well as particle identification via transition radiation (TR) detection. The straw tubes are operated with Xe-CO2-O2 70/27/3, a gas that combines the advantages of efficient TR absorption, a short electron drift time and minimum ageing effects. The modules of the barrel part of the TRT were built in the United States while the end-cap wheels are assembled at two Russian institutes. Acceptance tests of barrel modules and end-cap wheels are performed at CERN before assembly and integration with the Semiconductor Tracker (SCT) and the Pixel Detector. This thesis first describes simulations the TRT straw tube. The argon-based acceptance gas mixture as well as two xenon-based operating gases are examined for its properties. Drift velocities and Townsend coefficients are computed with the he...

  11. Excited meson radiative transitions from lattice QCD using variationally optimized operators

    Energy Technology Data Exchange (ETDEWEB)

    Shultz, Christian J. [Old Dominion Univ., Norfolk, VA (United States); Dudek, Jozef J. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States); Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2015-06-02

    We explore the use of 'optimized' operators, designed to interpolate only a single meson eigenstate, in three-point correlation functions with a vector-current insertion. These operators are constructed as linear combinations in a large basis of meson interpolating fields using a variational analysis of matrices of two-point correlation functions. After performing such a determination at both zero and non-zero momentum, we compute three-point functions and are able to study radiative transition matrix elements featuring excited state mesons. The required two- and three-point correlation functions are efficiently computed using the distillation framework in which there is a factorization between quark propagation and operator construction, allowing for a large number of meson operators of definite momentum to be considered. We illustrate the method with a calculation using anisotopic lattices having three flavors of dynamical quark all tuned to the physical strange quark mass, considering form-factors and transitions of pseudoscalar and vector meson excitations. In conclusion, the dependence on photon virtuality for a number of form-factors and transitions is extracted and some discussion of excited-state phenomenology is presented.

  12. Hot accretion flow with radiative cooling: state transitions in black hole X-ray binaries

    Science.gov (United States)

    Wu, Mao-Chun; Xie, Fu-Guo; Yuan, Ye-Fei; Gan, Zhaoming

    2016-06-01

    We investigate state transitions in black hole X-ray binaries through different parameters by using two-dimensional axisymmetric hydrodynamical simulation method. For radiative cooling in hot accretion flow, we take into account the bremsstrahlung, synchrotron and synchrotron self-Comptonization self-consistently in the dynamics. Our main result is that the state transitions occur when the accretion rate reaches a critical value dot{M} ˜ 3α dot{M}_Edd, above which cold and dense clumpy/filamentary structures are formed, embedded within the hot gas. We argued this mode likely corresponds to the proposed two-phase accretion model, which may be responsible for the intermediate state of black hole X-ray binaries. When the accretion rate becomes sufficiently high, the clumpy/filamentary structures gradually merge and settle down on to the mid-plane. Eventually the accretion geometry transforms to a disc-corona configuration. In summary, our results are consistent with the truncated accretion scenario for the state transition.

  13. Results of a direct search using synchrotron radiation for the low-energy $^{229}$Th nuclear isomeric transition

    CERN Document Server

    Jeet, Justin; Sullivan, Scott T; Rellergert, Wade G; Mirzadeh, Saed; Cassanho, A; Jenssen, H P; Tkalya, Eugene V; Hudson, Eric R

    2015-01-01

    We report the results of a direct search for the $^{229}$Th ($I^{p} = 3/2^+\\leftarrow 5/2^+$) nuclear isomeric transition, performed by exposing $^{229}$Th-doped LiSrAlF$_6$ crystals to tunable vacuum-ultraviolet synchrotron radiation and observing any resulting fluorescence. We also use existing nuclear physics data to establish a range of possible transition strengths for the isomeric transition. We find no evidence for the thorium nuclear transition between $7.3 \\mbox{eV}$ and $8.8 \\mbox{eV}$ with transition lifetime $(1-2)\\mbox{s} \\lesssim \\tau \\lesssim (2000-5600)\\mbox{s}$. This measurement excludes roughly half of the favored transition search area and can be used to direct future searches.

  14. Results of a Direct Search Using Synchrotron Radiation for the Low-Energy (229)Th Nuclear Isomeric Transition.

    Science.gov (United States)

    Jeet, Justin; Schneider, Christian; Sullivan, Scott T; Rellergert, Wade G; Mirzadeh, Saed; Cassanho, A; Jenssen, H P; Tkalya, Eugene V; Hudson, Eric R

    2015-06-26

    We report the results of a direct search for the (229)Th (I(π)=3/2(+)←5/2(+)) nuclear isomeric transition, performed by exposing (229)Th-doped LiSrAlF(6) crystals to tunable vacuum-ultraviolet synchrotron radiation and observing any resulting fluorescence. We also use existing nuclear physics data to establish a range of possible transition strengths for the isomeric transition. We find no evidence for the thorium nuclear transition between 7.3 eV and 8.8 eV with transition lifetime (1-2) s≲τ≲(2000-5600)  s. This measurement excludes roughly half of the favored transition search area and can be used to direct future searches.

  15. Energy cross-calibration from the first CREAM flight: transition radiation detector versus calorimeter

    CERN Document Server

    Maestro, P; Allison, P S; Bagliesi, M G; Beatty, J J; Bigongiari, G; Boyle, P J; Brandt, T J; Childers, J T; Conklin, N B; Coutu, S; Duvernois, M A; Ganel, O; Han, J H; Hyun, H J; Jeon, J A; Kim, K C; Lee, J K; Lee, M H; Lutz, L; Marrocchesi, P S; Malinine, A; Minnick, S; Mognet, S I; Nam, S; Nutter, S; Park, H; Park, I H; Park, N H; Seo, E S; Sina, R; Swordy, S; Wakely, S P; Wu, J; Yang, J; Yoon, Y S; Zei, R; Zinn, S Y

    2010-01-01

    The Cosmic Ray Energetics And Mass (CREAM) balloon experiment had two successful flights in 2004/05 and 2005/06. It was designed to perform energy measurements from a few GeV up to 1000 TeV, taking advantage of different detection techniques. The first instrument, CREAM-1, combined a transition radiation detector with a calorimeter to provide independent energy measurements of cosmicraynuclei. Each detector was calibrated with particle beams in a limited range of energies. In order to assess the absolute energy scale of the instrument and to investigate the systematic effects of each technique, a cross-calibration was performed by comparing the two independent energy estimates on selected samples of oxygen and carbon nuclei.

  16. Very high resolution optical transition radiation imaging system: Comparison between simulation and experiment

    CERN Document Server

    Bolzon, B; Aumeyr, Thomas; Boogert, Stewart Takashi; Karataev, Pavel; Kruchinin, Konstantin; Lefevre, Thibaut; Mazzoni, Stefano; Nevay, Laurence James; Shevelev, M; Terunuma, N; Urakawa, J; Welsch, Carsten

    2015-01-01

    Optical transition radiation (OTR) has become a commonly used method for 2D beam imaging measurements. In the Accelerator Test Facility 2 (ATF2) at KEK, beam sizes smaller than the OTR point spread function have been measured. Simulations of the OTR imaging system have been performed using the ZEMAX software to study the effects of optical errors such as aberrations, diffraction, and misalignments of optical components. This paper presents a comparison of simulations of the OTR point spread function with experimental data obtained at ATF2. It shows how the quantification and control of optical errors impacts on optimizing the resolution of the system. We also show that the OTR point spread function needs to be predicted accurately to optimize any optical system and to predict the error made on measurement.

  17. Performance of the ATLAS Transition Radiation Tracker Readout with High Energy Collisions at the LHC

    CERN Document Server

    Wagner, P; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker is the outermost of the three subsystems of the ATLAS Inner Detector. It contributes significantly to the precision of the momentum measurement of charged particles and to the identification of electrons. On the TRT front end electronics this is realized by discriminating the straw signal against two separate thresholds: a low one for tracking and a high one for electron identification. The electronics can also be configured to provide a trigger signal, which has been utilized to build a cosmic ray trigger that became extremely useful for the TRT as well as other subdetectors during ATLAS commissioning. This note will describe the TRT readout electronics and data acquisition, with emphasis on the experience gained during the first years of operation.

  18. Local Signal Processing of the ALICE Transition Radiation Detector at LHC (CERN)

    CERN Document Server

    Gutfleisch, Marcus

    2006-01-01

    The transition radiation detector of the heavy ion experiment ALICE at LHC (CERN) integrates parts of the data acquisition and trigger system. Therefore, a multi chip module has been developped which incorporates two microchips. Detector signals are preamplified and shaped (Preamplifier and Shaper Chip, PASA). Thereafter they are converted from analog to digital and are processed (Tracklet Processing Chip, TRAP). This thesis describes the digital signal processing of the TRAP chip. The input signals are filtered digitally. Then, they are analyzed by a preprocessor and four CPUs with respect to segments of tracks. The thesis covers the complete development from hardware design of filter and preprocessor, their calibration, programming of the CPUs, up to first application studies on a prototype system.

  19. Intense terahertz pulses from SLAC electron beams using coherent transition radiation.

    Science.gov (United States)

    Wu, Ziran; Fisher, Alan S; Goodfellow, John; Fuchs, Matthias; Daranciang, Dan; Hogan, Mark; Loos, Henrik; Lindenberg, Aaron

    2013-02-01

    SLAC has two electron accelerators, the Linac Coherent Light Source (LCLS) and the Facility for Advanced Accelerator Experimental Tests (FACET), providing high-charge, high-peak-current, femtosecond electron bunches. These characteristics are ideal for generating intense broadband terahertz (THz) pulses via coherent transition radiation. For LCLS and FACET respectively, the THz pulse duration is typically 20 and 80 fs RMS and can be tuned via the electron bunch duration; emission spectra span 3-30 THz and 0.5 THz-5 THz; and the energy in a quasi-half-cycle THz pulse is 0.2 and 0.6 mJ. The peak electric field at a THz focus has reached 4.4 GV/m (0.44 V/Å) at LCLS. This paper presents measurements of the terahertz pulses and preliminary observations of nonlinear materials response.

  20. Integrated High-Rate Transition Radiation Detector and Tracking Chamber for the LHC

    CERN Multimedia

    2002-01-01

    % RD-6 \\\\ \\\\Over the past five years, RD-6 has developed a transition radiation detector and charged particle tracker for high rate operation at LHC. The detector elements are based on C-fibre reinforced kapton straw tubes of 4~mm diameter filled with a Xenon gas mixture. Detailed measurements with and without magnetic field have been performed in test beams, and in particular have demonstrated the possibility of operating straw tubes at very high rate (up to 20~MHz) with accurate drift-time measurement accuracy. A full-scale engineering prototype containing 10~000 straws is presently under assembly and will be accurately measured with a powerful X-ray tube. Integrated front-end electronics with fast readout have been designed and successfully operated in test beam. \\\\ \\\\Finally extensive simulations performed for ATLAS have shown that such a detector will provide powerful pattern recognition, accurate momentum measurements, efficient level-2 triggering and excellent electron identification, even at the highe...

  1. Resonance effects of transition radiation emitted from thin foil stacks using electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Awata, Takaaki; Yajima, Kazuaki; Tanaka, Takashi [Kyoto Univ. (Japan). Faculty of Engineering] [and others

    1997-03-01

    Transition Radiation(TR) X rays are expected to be a high brilliant X-ray source because the interference among TR X rays emitted from many thin foils placed periodically in vacuum can increase their intensity and make them quasi-monochromatic. In order to study the interference (resonance) effects of TR, we measured the energy spectra of TR for several sets of thin-foil stacks at various emission angles. It was found that the resonance effects of TR are classified into intrafoil and interfoil resonances and the intensity of TR X rays increases nonlinearly with increasing foil number, attributing to the interfoil resonance. It became evident that the brilliance of TR is as high as that of SR. (author)

  2. A transition radiation detector interleaved with low-density targets for the NOE experiment

    CERN Document Server

    Alexandrov, K V; Bernardini, P; Brigida, M; Campana, D; Candela, A M; Caruso, R; Cassese, F; Ceres, A; D'Aquino, B; De Cataldo, G; De Mitri, I; Di Credico, A; Favuzzi, C; Fusco, P; Gargano, F; Giglietto, N; Giordano, F; Grillo, A; Guarino, F; Gustavino, C; Lamanna, E; Lauro, A; Leone, A; Loparco, F; Mancarella, G; Martello, D; Mazziotta, M N; Mikheyev, S P; Mongelli, M; Osteria, G; Palladino, Vittorio; Passeggio, G; Perchiazzi, M; Pontoniere, G; Rainó, A; Rocco, R; Romanucci, E; Rubizzo, U; Sacchetti, A; Scapparone, E; Spinelli, P; Tikhomirov, V; Vaccina, A; Vanzanella, E; Weber, M

    2001-01-01

    The NOE Collaboration has proposed a transition radiation detector (TRD) interleaved with marble targets to tag the electron decay channel of tau leptons produced by nu /sub tau /, eventually originated by nu /sub mu / oscillations in a long base line experiment. A reduced scale TRD detector prototype has been built and exposed to an electron/pion beam at the CERN PS. Discrimination capabilities between electrons and both charged and neutral pions, representing the main source of background for our measurement, have been determined obtaining rejection factors of the order of the tenth of percent for charged pions, and of a few percent for the neutral pion, matching the experiment requirements. The capabilities of this detector to measure the energy released by particles that start showering inside the targets are shown. A momentum resolution sigma /sub p//P

  3. Cosmic Ray Test of Mini-drift Thick Gas Electron Multiplier Chamber for Transition Radiation Detector

    CERN Document Server

    Yang, S; Buck, B; Li, C; Ljubicic, T; Majka, R; Shao, M; Smirnov, N; Visser, G; Xu, Z; Zhou, Y

    2014-01-01

    A thick gas electron multiplier (THGEM) chamber with an effective readout area of 10$\\times$10 cm$^{2}$ and a 11.3 mm ionization gap has been tested along with two regular gas electron multiplier (GEM) chambers in a cosmic ray test system. The thick ionization gap makes the THGEM chamber a mini-drift chamber. This kind mini-drift THGEM chamber is proposed as part of a transition radiation detector (TRD) for identifying electrons at an Electron Ion Collider (EIC) experiment. Through this cosmic ray test, an efficiency larger than 94$\\%$ and a spatial resolution $\\sim$220 $\\mu$m are achieved for the THGEM chamber at -3.65 kV. Thanks to its outstanding spatial resolution and thick ionization gap, the THGEM chamber shows excellent track reconstruction capability. The gain uniformity and stability of the THGEM chamber are also presented.

  4. Time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. (Argonne National Lab., IL (United States)); Wilke, M.D. (Los Alamos National Lab., NM (United States))

    1992-01-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

  5. Time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. [Argonne National Lab., IL (United States); Wilke, M.D. [Los Alamos National Lab., NM (United States)

    1992-09-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

  6. Further time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. (Argonne National Lab., IL (United States). Advanced Photon Source Accelerator Systems Div.); Wilke, M.D. (Los Alamos National Lab., NM (United States))

    1992-01-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 [mu]s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

  7. Further time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. [Argonne National Lab., IL (United States). Advanced Photon Source Accelerator Systems Div.; Wilke, M.D. [Los Alamos National Lab., NM (United States)

    1992-12-31

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

  8. Optical transition radiation measurements for the Los Alamos and Boeing Free-Electron Laser experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H.; Feldman, R.B.; Feldman, D.W.; Apgar, S.A.; Calsten, B.E.; Fiorito, R.B.; Rule, D.W.

    1988-01-01

    Optical transition radiation (OTR) measurements of the electron-beam emittance have been performed at a location just before the wiggler in the Los Alamos Free-Electron Laser (FEL) experiment. Beam profiles and beam divergence patterns from a single macropulse were recorded simultaneously using two intensified charge-injection device (CID) television cameras and an optical beamsplitter. Both single-foil OTR and two-foil OTR interference experiments were performed. Preliminary results are compared to a reference variable quadrupole, single screen technique. New aspects of using OTR properties for pointing the e-beam on the FEL oscillator axis, as well as measuring e-beam emittance are addressed. 7 refs., 9 figs.

  9. High-current CW beam profile monitors using transition radiation at CEBAF

    Science.gov (United States)

    Piot, P.; Denard, J.-C.; Adderley, P.; Capek, K.; Feldl, E.

    1997-01-01

    One way of measuring the profile of CEBAF's low-emittance, high-power beam is to use the optical transition radiation (OTR) emitted from a thin foil surface when the electron beam passes through it. We present the design of a monitor using the forward OTR emitted from a 0.25-μm carbon foil. We believe that the monitor will resolve three main issues: i) whether the maximum temperature of the foil stays below the melting point, ii) whether the beam loss remains below 0.5%, in order not to trigger the machine protection system, and iii) whether the monitor resolution (unlike that of synchrotron radiation monitors) is better than the product λγ. It seems that the most serious limitation for CEBAF is the beam loss due to beam scattering. We present results from Keil's theory and simulations from the computer code GEANT as well as measurements with aluminum foils with a 45-MeV electron beam. We also present a measurement of a 3.2-GeV beam profile that is much smaller than λγ, supporting Rule and Fiorito's calculations of the OTR resolution limit due to diffraction.

  10. Aging and Gas Filtration Studies in the ATLAS Transition Radiation Tracker

    CERN Document Server

    Sprachmann, Gerald; Störi, Herbert

    2006-01-01

    The Transition Radiation Tracker (TRT) is one of three particle tracking detectors of the ATLAS Inner Detector whose goal is to exploit the highly exciting new physics potential at CERN's next accelerator, the so-called Large Hadron Collider (LHC). The TRT consists of 370000 straw proportional tubes of 4 mm diameter with a 30 micron anode wire, which will be operated with a Xe/CO2/O2 gas mixture at a high voltage of approximately 1.5 kV. This detector enters a new area that requires it to operate at unprecedented high rates and integrated particle fluxes. Full functionality of the detector over the lifetime (10 years) of the experiment is demanded. Aging of gaseous detectors is a term for the degradation of detector performance during exposure to ionizing radiation. This phenomenon involves very complex physical and chemical processes that are induced by pollution originating from very small amounts of silicon-based substances in some components of the gas system. This work presents a review of previous aging...

  11. Spin-flip processes and radiative decay of dark intravalley excitons in transition metal dichalcogenide monolayers

    Science.gov (United States)

    Slobodeniuk, A. O.; Basko, D. M.

    2016-09-01

    We perform a theoretical study of radiative decay of dark intravalley excitons in transition metal dichalcogenide monolayers. This decay necessarily involves an electronic spin flip. The intrinsic decay mechanism due to interband spin-flip dipole moment perpendicular to the monolayer plane, gives a rate about 100-1000 times smaller than that of bright excitons. However, we find that this mechanism also introduces an energy splitting due to a local field effect, and the whole oscillator strength is contained in the higher-energy component, while the lowest-energy state remains dark and needs an extrinsic spin-flip mechanism for the decay. Rashba effect due to a perpendicular electric field or a dielectric substrate, gives a negligible radiative decay rate (about 107 times slower than that of bright excitons). Spin flip due to Zeeman effect in a sufficiently strong in-plane magnetic field can give a decay rate comparable to that due to the intrinsic interband spin-flip dipole.

  12. Construction of an end-cap module prototype for the ATLAS transition radiation tracker

    CERN Document Server

    Danielsson, H

    2000-01-01

    We have designed, built and tested an 8-plane module prototype for the end-cap of the ATLAS TRT (Transition Radiation Tracker). The overall mechanics as well as the detailed design of individual components are presented. The prototype contains over 6000 straw tubes with a diameter of 4 mm, filled with an active gas mixture of 70% Xe, 20% CF4 and 10% CO//2. Very tight requirements on radiation hardness (10 Mrad and 2 multiplied by l0**1**4 neutrons per cm**2) straw straightness (sagitta less than 300 m), wire positions and leak tightness put great demands upon design and assembly. In order to verify the design, the stability of the wire tension, straw straightness, high-voltage performance and total leak rate have been measured and the results are presented. Some examples of dedicated assembly tooling and testing procedures are also given. Finally, the results of the calculations and measurements of both mechanical behaviour and wire offset are presented. 6 Refs.

  13. Energy levels, radiative rates and electron impact excitation rates for transitions in Al X

    CERN Document Server

    Aggarwal, K M

    2013-01-01

    Energy levels, radiative rates and lifetimes are calculated among the lowest 98 levels of the n <= 4 configurations of Be-like Al X. The GRASP (General-purpose Relativistic Atomic Structure Package) is adopted and data are provided for all E1, E2, M1 and M2 transitions. Similar data are also obtained with the Flexible Atomic Code (FAC) to assess the accuracy of the calculations. Based on comparisons between calculations with the two codes as well as with available measurements, our listed energy levels are assessed to be accurate to better than 0.3%. However, the accuracy for radiative rates and lifetimes is estimated to be about 20%. Collision strengths are also calculated for which the Dirac Atomic R-matrix Code (DARC) is used. A wide energy range (up to 380 Ryd) is considered and resonances resolved in a fine energy mesh in the thresholds region. The collision strengths are subsequently averaged over a Maxwellian velocity distribution to determine effective collision strengths up to a temperature of 1.6...

  14. Energy levels, radiative rates and electron impact excitation rates for transitions in C III

    CERN Document Server

    Aggarwal, K M

    2015-01-01

    We report energy levels, radiative rates (A-values) and lifetimes for the astrophysically-important Be-like ion C III. For the calculations, 166 levels belonging to the $n \\le$ 5 configurations are considered and the {\\sc grasp} (General-purpose Relativistic Atomic Structure Package) is adopted. Einstein A-coefficients are provided for all E1, E2, M1 and M2 transitions, while lifetimes are compared with available measurements as well as theoretical results, and no large discrepancies noted. Our energy levels are assessed to be accurate to better than 1\\% for a majority of levels, and A-values to better than 20\\% for most transitions. Collision strengths are also calculated, for which the Dirac Atomic R-matrix Code ({\\sc darc}) is used. A wide energy range, up to 21 Ryd, is considered and resonances resolved in a fine energy mesh in the thresholds region. The collision strengths are subsequently averaged over a Maxwellian velocity distribution to determine effective collision strengths up to a temperature of 8...

  15. Hot accretion flow with radiative cooling: state transitions in black hole X-ray binaries

    CERN Document Server

    Wu, Mao-Chun; Yuan, Ye-Fei; Gan, Zhao-Ming

    2016-01-01

    We investigate state transitions in black hole X-ray binaries through different parameters by using two-dimensional axisymmetric hydrodynamical simulation method. For radiative cooling in hot accretion flow, we take into account the bremsstrahlung, synchrotron and synchrotron-self Comptonization self-consistently in the dynamics. Our main result is that the state transitions occur when the accretion rate reaches a critical value $\\dot M \\sim 3\\alpha\\ \\dot M_{\\rm Edd}$, above which cold and dense clumpy/filamentary structures are formed, embedded within the hot gas. We argued this mode likely corresponds to the proposed two-phase accretion model, which may be responsible for the intermediate state of black hole X-ray binaries. When the accretion rate becomes sufficiently high, the clumpy/filamentary structures gradually merge and settle down onto the mid-plane. Eventually the accretion geometry transforms to a disc-corona configuration. In summary our results are consistent with the truncated accretion scenari...

  16. Optimization of a transition radiation detector for the compressed baryonic matter experiment

    Energy Technology Data Exchange (ETDEWEB)

    Arend, Andreas

    2014-07-01

    The Transition Radiation Detector (TRD) of the compressed baryonic matter (CBM) experiment at FAIR has to provide electron-pion separation as well as charged-particle tracking. Within this work, thin and symmetric Multi-Wire Proportional Chambers (MWPCs) without additional drift region were proposed. the proposed prototypes feature a foil-based entrance window to minimize the material budget and to reduce the absorption probability of the generated TR photon. Based on the conceptual design of thin and symmetric MWPCs without drift region, multiple prototypes were constructed and their performance presented within this thesis. With the constructed prototypes of generations II and III the geometries of the wire and cathode planes were determined to be 4+4 mm and 5+5 mm. Based on the results of a performed test beam campaign in 2011 with this prototypes new prototypes of generation IV were manufactured and tested in a subsequent test beam campaign in 2012. Prototypes of different radiators were developed together with the MWPC prototypes. Along with regular foil radiators, foam-based radiator types made of polyethylene foam were utilized. Also radiators constructed in a sandwich design, which used different fiber materials confined with solid foam sheets, were used. For the prototypes without drift region, simulations of the electrostatic and mechanical properties were performed. The GARFIELD software package was used to simulate the electric field and to determine the resulting drift lines of the generated electrons. The mean gas amplification depending on the utilized gas and the applied anode voltage was simulated and the gas-gain homogeneity was verified. Since the thin foil-based entrance window experiences a deformation due to pressure differences inside and outside the MWPC, the variation on the gas gain depending on the deformation was simulated. The mechanical properties focusing on the stability of the entrance window was determined with a finiteelement

  17. The Impact of Radiation on the GABLS3 Large-Eddy Simulation through the Night and during the Morning Transition

    NARCIS (Netherlands)

    Edwards, J.M.; Basu, S.; Bosveld, F.C.; Holtslag, A.A.M.

    2014-01-01

    Large-eddy simulation in the GABLS3 intercomparison is concerned with the developed stable boundary layer (SBL) and the ensuing morning transition. The impact of radiative transfer on simulations of this case is assessed. By the time of the reversal of the surface buoyancy flux, a modest reduction o

  18. The transition radiation. I: numerical study of the angular and spectral distributions; Le rayonnement de transition optique. I: etude numerique des distributions angulaires et spectrales

    Energy Technology Data Exchange (ETDEWEB)

    Couillaud, Ch.; Haouat, G

    1999-07-01

    The optical transition radiation (OTR) is extensively used since many years as a beam visualisation tool on electron accelerators and serves to monitor the beam during its transport adjustment. Its spatial and temporal characteristics make it very attractive as a diagnostic tool and allow measurements of the beam energy and transverse and longitudinal emittances. We present a numerical study of the transition radiation process in the optical region of the radiated spectrum (OTR) and in the higher part (XTR). Spatial and spectral properties are described. They are used to describe experimental observations performed on the ELSA electron-beam facility. An analytical description of the angular distributions of visible radiation emitted by birefringent targets, used as OTR sources, is also proposed. We also analyze interference phenomena between two OTR sources and show the advantage of using this interferometer as a diagnostic tool for tenth MeV electron accelerators. At last, we present an analytical model allowing to design a soft X-ray source to be installed on the ELSA facility and using either a multi-foil stack or a multilayer of two materials of different permittivities. (authors)

  19. The Effects of Electron Radiation on the Glass Transition Temperature of a Polyetherimide.

    Science.gov (United States)

    Kern, Kristen Tulloch

    The effects of electron radiation on a polyetherimide (PEI), Ultem^{cdot}, were investigated. In particular, the changes in the glass transition temperature (T_{g} ) with absorbed radiation dose were studied. The polymer was exposed to mono-energetic beams of 100-keV electrons and 1.0-MeV electrons for doses up to 100 megagray (MGy). Dosimetry for the exposures was based on Monte -Carlo simulations of the transfer of energy from an energetic electron to the polymer and on comparison to Nylon standards. Dynamic mechanical analysis was used to determine the T _{g} for non-exposed PEI and the changes in T_{g} resulting from irradiation. The T_{g} did not change significantly for doses up to and including 75 MGy, while a significant increase in T_ {g} occurred for a dose of 100 MGy. The cross-link and chain scission densities in the irradiated PEI were determined using infrared spectroscopy. The cross -link density increased with dose for all doses investigated. The chain scission density increased with dose for doses up to 75 MGy, but was lower for a dose of 100 MGy than for a dose of 75 MGy. Radical population kinetics, based in part on data from an electron paramagnetic resonance study, were correlated with the cross-link density and chain scission density to investigate the mechanism for the observed density variations with dose. The radical population simulations suggest that chain scissioning occurs less readily when the average radical separation during the exposure is less than three molecular radii. Finally, a model for the combined effects of cross-linking and chain scissioning is proposed which combines a statistical-mechanical model for the change in T_{g} with cross-link density and a free-volume model for the change in T _{g} with chain scission density.

  20. Performance of the ATLAS Transition Radiation Tracker in Run 1 of the LHC: tracker properties

    CERN Document Server

    Aaboud, Morad; Abbott, Brad; Abdallah, Jalal; Abdinov, Ovsat; Abeloos, Baptiste; Abidi, Syed Haider; AbouZeid, Ossama; Abraham, Nicola; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adachi, Shunsuke; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adersberger, Michael; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agheorghiesei, Catalin; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akatsuka, Shunichi; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Ali, Babar; Aliev, Malik; Alimonti, Gianluca; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allen, Benjamin William; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Alshehri, Azzah Aziz; Alstaty, Mahmoud; Alvarez Gonzalez, Barbara; Άlvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antel, Claire; Antonelli, Mario; Antonov, Alexey; Antrim, Daniel Joseph; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Araujo Ferraz, Victor; Arce, Ayana; Ardell, Rose Elisabeth; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Armitage, Lewis James; Arnaez, Olivier; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Artz, Sebastian; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baas, Alessandra; Baca, Matthew John; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Baines, John; Bajic, Milena; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisits, Martin-Stefan; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska-Blenessy, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barranco Navarro, Laura; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Bechtle, Philip; Beck, Hans~Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bedognetti, Matteo; Bee, Christopher; Beermann, Thomas; Begalli, Marcia; Begel, Michael; Behr, Janna Katharina; Bell, Andrew Stuart; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Belyaev, Nikita; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez, Jose; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Beringer, Jürg; Berlendis, Simon; Bernard, Nathan Rogers; Bernardi, Gregorio; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertram, Iain Alexander; Bertsche, Carolyn; Bertsche, David; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethani, Agni; Bethke, Siegfried; Bevan, Adrian John; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bielski, Rafal; Biesuz, Nicolo Vladi; Biglietti, Michela; Bilbao De Mendizabal, Javier; Billoud, Thomas Remy Victor; Bilokon, Halina; Bindi, Marcello; Bingul, Ahmet; Bini, Cesare; Biondi, Silvia; Bisanz, Tobias; Bittrich, Carsten; Bjergaard, David Martin; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blue, Andrew; Blum, Walter; Blumenschein, Ulrike; Blunier, Sylvain; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boehler, Michael; Boerner, Daniela; Bogavac, Danijela; Bogdanchikov, Alexander; Bohm, Christian; Boisvert, Veronique; Bokan, Petar; Bold, Tomasz; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Bortfeldt, Jonathan; Bortoletto, Daniela; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Bossio Sola, Jonathan David; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Boutle, Sarah Kate; Boveia, Antonio; Boyd, James; Boyko, Igor; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Breaden Madden, William Dmitri; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Lydia; Brenner, Richard; Bressler, Shikma; Briglin, Daniel Lawrence; Bristow, Timothy Michael; Britton, Dave; Britzger, Daniel; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Broughton, James; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruni, Alessia; Bruni, Graziano; Bruni, Lucrezia Stella; Brunt, Benjamin; Bruschi, Marco; Bruscino, Nello; Bryant, Patrick; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Buchholz, Peter; Buckley, Andrew; Budagov, Ioulian; Buehrer, Felix; Bugge, Magnar Kopangen; Bulekov, Oleg; Bullock, Daniel; Burckhart, Helfried; Burdin, Sergey; Burgard, Carsten Daniel; Burger, Angela Maria; Burghgrave, Blake; Burka, Klaudia; Burke, Stephen; Burmeister, Ingo; Burr, Jonathan Thomas Peter; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Butler, John; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Buzykaev, Aleksey; Cabrera Urbán, Susana; Caforio, Davide; Cairo, Valentina; Cakir, Orhan; Calace, Noemi; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Callea, Giuseppe; Caloba, Luiz; Calvente Lopez, Sergio; Calvet, David; Calvet, Samuel; Calvet, Thomas Philippe; Camacho Toro, Reina; Camarda, Stefano; Camarri, Paolo; Cameron, David; Caminal Armadans, Roger; Camincher, Clement; Campana, Simone; Campanelli, Mario; Camplani, Alessandra; Campoverde, Angel; Canale, Vincenzo; Cano Bret, Marc; Cantero, Josu; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Carbone, Ryne Michael; Cardarelli, Roberto; Cardillo, Fabio; Carli, Ina; Carli, Tancredi; Carlino, Gianpaolo; Carlson, Benjamin Taylor; Carminati, Leonardo; Carney, Rebecca; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Casper, David William; Castelijn, Remco; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Caudron, Julien; Cavaliere, Viviana; Cavallaro, Emanuele; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Celebi, Emre; Ceradini, Filippo; Cerda Alberich, Leonor; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Stephen Kam-wah; Chan, Wing Sheung; Chan, Yat Long; Chang, Philip; Chapman, John Derek; Charlton, Dave; Chatterjee, Avishek; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Che, Siinn; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Shion; Chen, Xin; Chen, Ye; Cheng, Hok Chuen; Cheng, Huajie; Cheng, Yangyang; Cheplakov, Alexander; Cheremushkina, Evgenia; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiarelli, Giorgio; Chiodini, Gabriele; Chisholm, Andrew; Chitan, Adrian; Chiu, Yu Him Justin; Chizhov, Mihail; Choi, Kyungeon; Chomont, Arthur Rene; Chouridou, Sofia; Chow, Bonnie Kar Bo; Christodoulou, Valentinos; Chromek-Burckhart, Doris; Chu, Ming Chung; Chudoba, Jiri; Chuinard, Annabelle Julia; Chwastowski, Janusz; Chytka, Ladislav; Ciftci, Abbas Kenan; Cinca, Diane; Cindro, Vladimir; Cioara, Irina Antonela; Ciocca, Claudia; Ciocio, Alessandra; Cirotto, Francesco; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Brian Lee; Clark, Michael; Clark, Philip James; Clarke, Robert; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Colasurdo, Luca; Cole, Brian; Colijn, Auke-Pieter; Collot, Johann; Colombo, Tommaso; Conde Muiño, Patricia; Coniavitis, Elias; Connell, Simon Henry; Connelly, Ian; Consorti, Valerio; Constantinescu, Serban; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cormier, Felix; Cormier, Kyle James Read; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Crawley, Samuel Joseph; Creager, Rachael; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cribbs, Wayne Allen; Crispin Ortuzar, Mireia; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cueto, Ana; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cúth, Jakub; Czirr, Hendrik; Czodrowski, Patrick; D'amen, Gabriele; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dado, Tomas; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Dandoy, Jeffrey; Dang, Nguyen Phuong; Daniells, Andrew Christopher; Dann, Nicholas Stuart; Danninger, Matthias; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Daubney, Thomas; Davey, Will; David, Claire; Davidek, Tomas; Davies, Merlin; Davison, Peter; Dawe, Edmund; Dawson, Ian; De, Kaushik; de Asmundis, Riccardo; De Benedetti, Abraham; De Castro, Stefano; De Cecco, Sandro; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Maria, Antonio; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vasconcelos Corga, Kevin; De Vivie De Regie, Jean-Baptiste; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Dehghanian, Nooshin; Deigaard, Ingrid; Del Gaudio, Michela; Del Peso, Jose; Del Prete, Tarcisio; Delgove, David; Deliot, Frederic; Delitzsch, Chris Malena; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; DeMarco, David; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Denysiuk, Denys; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Dette, Karola; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Clemente, William Kennedy; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Micco, Biagio; Di Nardo, Roberto; Di Petrillo, Karri Folan; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaconu, Cristinel; Diamond, Miriam; Dias, Flavia; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Díez Cornell, Sergio; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Djuvsland, Julia Isabell; Barros do Vale, Maria Aline; Dobos, Daniel; Dobre, Monica; Doglioni, Caterina; Dolejsi, Jiri; Dolezal, Zdenek; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Drechsler, Eric; Dris, Manolis; Du, Yanyan; Duarte-Campderros, Jorge; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Dudder, Andreas Christian; Duffield, Emily Marie; Duflot, Laurent; Dührssen, Michael; Dumancic, Mirta; Dumitriu, Ana Elena; Duncan, Anna Kathryn; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Duschinger, Dirk; Dutta, Baishali; Dyndal, Mateusz; Eckardt, Christoph; Ecker, Katharina Maria; Edgar, Ryan Christopher; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellajosyula, Venugopal; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Elliot, Alison; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Ennis, Joseph Stanford; Erdmann, Johannes; Ereditato, Antonio; Ernis, Gunar; Ernst, Michael; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Fabbri, Federica; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Falla, Rebecca Jane; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farina, Christian; Farina, Edoardo Maria; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Faucci Giannelli, Michele; Favareto, Andrea; Fawcett, William James; Fayard, Louis; Fedin, Oleg; Fedorko, Wojciech; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenyuk, Alexander; Feremenga, Last; Fernandez Martinez, Patricia; Fernandez Perez, Sonia; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Fischer, Adam; Fischer, Cora; Fischer, Julia; Fisher, Wade Cameron; Flaschel, Nils; Fleck, Ivor; Fleischmann, Philipp; Fletcher, Rob Roy MacGregor; Flick, Tobias; Flierl, Bernhard Matthias; Flores Castillo, Luis; Flowerdew, Michael; Forcolin, Giulio Tiziano; Formica, Andrea; Forti, Alessandra; Foster, Andrew Geoffrey; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Francis, David; Franconi, Laura; Franklin, Melissa; Frate, Meghan; Fraternali, Marco; Freeborn, David; Fressard-Batraneanu, Silvia; Freund, Benjamin; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fusayasu, Takahiro; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gach, Grzegorz; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Louis Guillaume; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Ganguly, Sanmay; Gao, Jun; Gao, Yanyan; Gao, Yongsheng; Garay Walls, Francisca; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gascon Bravo, Alberto; Gasnikova, Ksenia; Gatti, Claudio; Gaudiello, Andrea; Gaudio, Gabriella; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Gee, Norman; Geisen, Marc; Geisler, Manuel Patrice; Gellerstedt, Karl; Gemme, Claudia; Genest, Marie-Hélène; Geng, Cong; Gentile, Simonetta; Gentsos, Christos; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghasemi, Sara; Ghneimat, Mazuza; Giacobbe, Benedetto; Giagu, Stefano; Giannetti, Paola; Gibson, Stephen; Gignac, Matthew; Gilchriese, Murdock; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giorgi, Filippo Maria; Giraud, Pierre-Francois; Giromini, Paolo; Giugni, Danilo; Giuli, Francesco; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gkougkousis, Evangelos Leonidas; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Goblirsch-Kolb, Maximilian; Godlewski, Jan; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gonçalo, Ricardo; Goncalves Gama, Rafael; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Giulia; Gonella, Laura; Gongadze, Alexi; González de la Hoz, Santiago; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Goudet, Christophe Raymond; Goujdami, Driss; Goussiou, Anna; Govender, Nicolin; Gozani, Eitan; Graber, Lars; Grabowska-Bold, Iwona; Gradin, Per Olov Joakim; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Gratchev, Vadim; Gravila, Paul Mircea; Gray, Heather; Greenwood, Zeno Dixon; Grefe, Christian; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Grevtsov, Kirill; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grivaz, Jean-Francois; Groh, Sabrina; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Grout, Zara Jane; Guan, Liang; Guan, Wen; Guenther, Jaroslav; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Gui, Bin; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Guo, Wen; Guo, Yicheng; Gupta, Ruchi; Gupta, Shaun; Gustavino, Giuliano; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guyot, Claude; Guzik, Marcin Pawel; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Hadef, Asma; Hageböck, Stephan; Hagihara, Mutsuto; Hakobyan, Hrachya; Haleem, Mahsana; Haley, Joseph; Halladjian, Garabed; Hallewell, Gregory David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamilton, Andrew; Hamity, Guillermo Nicolas; Hamnett, Phillip George; Han, Liang; Han, Shuo; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Haney, Bijan; Hanke, Paul; Hanna, Remie; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Maike Christina; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Hariri, Faten; Harkusha, Siarhei; Harrington, Robert; Harrison, Paul Fraser; Hartjes, Fred; Hartmann, Nikolai Marcel; Hasegawa, Makoto; Hasegawa, Yoji; Hasib, Ahmed; Hassani, Samira; Haug, Sigve; Hauser, Reiner; Hauswald, Lorenz; Havener, Laura Brittany; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hayakawa, Daiki; Hayden, Daniel; Hays, Chris; Hays, Jonathan Michael; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Jochen Jens; Heinrich, Lukas; Heinz, Christian; Hejbal, Jiri; Helary, Louis; Held, Alexander; Hellman, Sten; Helsens, Clement; Henderson, James; Henderson, Robert; Heng, Yang; Henkelmann, Steffen; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Herbert, Geoffrey Henry; Herde, Hannah; Herget, Verena; Hernández Jiménez, Yesenia; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Herwig, Theodor Christian; Hesketh, Gavin Grant; Hessey, Nigel; Hetherly, Jeffrey Wayne; Higashino, Satoshi; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillier, Stephen; Hinchliffe, Ian; Hirose, Minoru; Hirschbuehl, Dominic; Hiti, Bojan; Hladik, Ondrej; Hoad, Xanthe; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hohn, David; Holmes, Tova Ray; Homann, Michael; Honda, Shunsuke; Honda, Takuya; Hong, Tae Min; Hooberman, Benjamin Henry; Hopkins, Walter; Horii, Yasuyuki; Horton, Arthur James; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howarth, James; Hoya, Joaquin; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hrynevich, Aliaksei; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Qipeng; Hu, Shuyang; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Huo, Peng; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuriy; Iliadis, Dimitrios; Ilic, Nikolina; Introzzi, Gianluca; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Ishijima, Naoki; Ishino, Masaya; Ishitsuka, Masaki; Issever, Cigdem; Istin, Serhat; Ito, Fumiaki; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jabbar, Samina; Jackson, Paul; Jain, Vivek; Jakobi, Katharina Bianca; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jamin, David Olivier; Jana, Dilip; Jansky, Roland; Janssen, Jens; Janus, Michel; Janus, Piotr Andrzej; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Javurkova, Martina; Jeanneau, Fabien; Jeanty, Laura; Jejelava, Juansher; Jelinskas, Adomas; Jenni, Peter; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Hai; Jiang, Yi; Jiang, Zihao; Jiggins, Stephen; Jimenez Pena, Javier; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Jivan, Harshna; Johansson, Per; Johns, Kenneth; Johnson, Christian; Johnson, William Joseph; Jon-And, Kerstin; Jones, Roger; Jones, Sarah; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Jovicevic, Jelena; Ju, Xiangyang; Juste Rozas, Aurelio; Köhler, Markus Konrad; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kahn, Sebastien Jonathan; Kaji, Toshiaki; Kajomovitz, Enrique; Kalderon, Charles William; Kaluza, Adam; Kama, Sami; Kamenshchikov, Andrey; Kanaya, Naoko; Kaneti, Steven; Kanjir, Luka; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kaplan, Laser Seymour; Kar, Deepak; Karakostas, Konstantinos; Karastathis, Nikolaos; Kareem, Mohammad Jawad; Karentzos, Efstathios; Karpov, Sergey; Karpova, Zoya; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kasahara, Kota; Kashif, Lashkar; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Kato, Chikuma; Katre, Akshay; Katzy, Judith; Kawade, Kentaro; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kay, Ellis; Kazanin, Vassili; Keeler, Richard; Kehoe, Robert; Keller, John; Kempster, Jacob Julian; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Keyes, Robert; Khader, Mazin; Khalil-zada, Farkhad; Khanov, Alexander; Kharlamov, Alexey; Kharlamova, Tatyana; Khodinov, Alexander; Khoo, Teng Jian; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kido, Shogo; Kilby, Callum; Kim, Hee Yeun; Kim, Shinhong; Kim, Young-Kee; Kimura, Naoki; Kind, Oliver Maria; King, Barry; Kirchmeier, David; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiuchi, Kenji; Kivernyk, Oleh; Kladiva, Eduard; Klapdor-kleingrothaus, Thorwald; Klein, Matthew Henry; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klioutchnikova, Tatiana; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Knapik, Joanna; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Aine; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koffas, Thomas; Koffeman, Els; Köhler, Nicolas Maximilian; Koi, Tatsumi; Kolb, Mathis; Koletsou, Iro; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; 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Kubota, Takashi; Kucuk, Hilal; Kuday, Sinan; Kuechler, Jan Thomas; Kuehn, Susanne; Kugel, Andreas; Kuger, Fabian; Kuhl, Thorsten; Kukhtin, Victor; Kukla, Romain; Kulchitsky, Yuri; Kuleshov, Sergey; Kulinich, Yakov Petrovich; Kuna, Marine; Kunigo, Takuto; Kupco, Alexander; Kuprash, Oleg; Kurashige, Hisaya; Kurchaninov, Leonid; Kurochkin, Yurii; Kurth, Matthew Glenn; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwan, Tony; Kyriazopoulos, Dimitrios; La Rosa, Alessandro; La Rosa Navarro, Jose Luis; La Rotonda, Laura; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Lammers, Sabine; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lanfermann, Marie Christine; Lang, Valerie Susanne; Lange, J örn Christian; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Lapertosa, Alessandro; Laplace, Sandrine; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Lazovich, Tomo; Lazzaroni, Massimo; Le, Brian; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Quilleuc, Eloi; LeBlanc, Matthew Edgar; LeCompte, Thomas; Ledroit-Guillon, Fabienne; Lee, Claire Alexandra; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Benoit; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leight, William Axel; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Lerner, Giuseppe; Leroy, Claude; Lesage, Arthur; Lester, Christopher; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Dave; Leyton, Michael; Li, Bing; Li, Changqiao; Li, Haifeng; Li, Lei; Li, Liang; Li, Qi; Li, Shu; Li, Xingguo; Li, Yichen; Liang, Zhijun; Liberti, Barbara; Liblong, Aaron; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limosani, Antonio; Lin, Simon; Lin, Tai-Hua; Lindquist, Brian Edward; Lionti, Anthony Eric; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Hao; Liu, Hongbin; Liu, Jian; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Minghui; Liu, Yanlin; Liu, Yanwen; Livan, Michele; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo, Cheuk Yee; Lo Sterzo, Francesco; Lobodzinska, Ewelina Maria; Loch, Peter; Loebinger, Fred; Loew, Kevin Michael; Loginov, Andrey; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Long, Brian Alexander; Long, Jonathan David; Long, Robin Eamonn; Longo, Luigi; Looper, Kristina Anne; Lopez, Jorge; Lopez Mateos, David; Lopez Paz, Ivan; Lopez Solis, Alvaro; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Lösel, Philipp Jonathan; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lu, Haonan; Lu, Nan; Lu, Yun-ju; 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Mann, Alexander; Manousos, Athanasios; Mansoulie, Bruno; Mansour, Jason Dhia; Mantifel, Rodger; Mantoani, Matteo; Manzoni, Stefano; Mapelli, Livio; Marceca, Gino; March, Luis; Marchiori, Giovanni; Marcisovsky, Michal; Marjanovic, Marija; Marley, Daniel; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Martensson, Mikael; Marti-Garcia, Salvador; Martin, Christopher Blake; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Mario; Martinez Outschoorn, Verena; Martin-Haugh, Stewart; Martoiu, Victor Sorin; Martyniuk, Alex; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Lorenzo; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mättig, Peter; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Maznas, Ioannis; Mazza, Simone Michele; Mc Fadden, Neil Christopher; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McClymont, Laurie; McDonald, Emily; Mcfayden, Josh; Mchedlidze, Gvantsa; McMahon, Steve; McNamara, Peter Charles; McPherson, Robert; Meehan, Samuel; Megy, Theo Jean; Mehlhase, Sascha; Mehta, Andrew; Meideck, Thomas; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Melini, Davide; Mellado Garcia, Bruce Rafael; Melo, Matej; Meloni, Federico; Menary, Stephen Burns; Meng, Lingxin; Meng, Xiangting; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mergelmeyer, Sebastian; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer Zu Theenhausen, Hanno; Miano, Fabrizio; Middleton, Robin; Miglioranzi, Silvia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Milesi, Marco; Milic, Adriana; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Minaenko, Andrey; Minami, Yuto; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Minegishi, Yuji; Ming, Yao; Mir, Lluisa-Maria; Mistry, Khilesh; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Miucci, Antonio; Miyagawa, Paul; Mizukami, Atsushi; Mjörnmark, Jan-Ulf; Mlynarikova, Michaela; Moa, Torbjoern; Mochizuki, Kazuya; Mogg, Philipp; Mohapatra, Soumya; Molander, Simon; Moles-Valls, Regina; Monden, Ryutaro; Mondragon, Matthew Craig; Mönig, Klaus; Monk, James; Monnier, Emmanuel; Montalbano, Alyssa; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Stefanie; Mori, Daniel; Mori, Tatsuya; Morii, Masahiro; Morinaga, Masahiro; Morisbak, Vanja; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moschovakos, Paris; Mosidze, Maia; Moss, Harry James; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Ralph Soeren Peter; Muenstermann, Daniel; Mullen, Paul; Mullier, Geoffrey; Munoz Sanchez, Francisca Javiela; Murray, Bill; Musheghyan, Haykuhi; Muškinja, Miha; Myagkov, Alexey; Myska, Miroslav; Nachman, Benjamin Philip; Nackenhorst, Olaf; Nagai, Koichi; Nagai, Ryo; Nagano, Kunihiro; Nagasaka, Yasushi; Nagata, Kazuki; Nagel, Martin; Nagy, Elemer; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Naranjo Garcia, Roger Felipe; Narayan, Rohin; Narrias Villar, Daniel Isaac; Naryshkin, Iouri; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Andrew; Nelson, Michael Edward; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Ng, Tsz Yu; Nguyen Manh, Tuan; Nickerson, Richard; Nicolaidou, Rosy; Nielsen, Jason; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Jon Kerr; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishu, Nishu; Nisius, Richard; Nobe, Takuya; Noguchi, Yohei; Nomachi, Masaharu; Nomidis, Ioannis; Nomura, Marcelo Ayumu; Nooney, Tamsin; Nordberg, Markus; Norjoharuddeen, Nurfikri; Novgorodova, Olga; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nurse, Emily; Nuti, Francesco; O'Neil, Dugan; O'Rourke, Abigail Alexandra; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Ochoa-Ricoux, Juan Pedro; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Oide, Hideyuki; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Oleiro Seabra, Luis Filipe; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onogi, Kouta; Onyisi, Peter; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Owen, Mark; Owen, Rhys Edward; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Pacheco Rodriguez, Laura; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganini, Michela; Paige, Frank; Pais, Preema; Palacino, Gabriel; Palazzo, Serena; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Panagiotopoulou, Evgenia; Panagoulias, Ilias; Pandini, Carlo Enrico; Panduro Vazquez, William; Pani, Priscilla; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Adam Jackson; Parker, Michael Andrew; Parker, Kerry Ann; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pascuzzi, Vincent; Pasner, Jacob Martin; Pasqualucci, Enrico; Passaggio, Stefano; Pastore, Francesca; Pataraia, Sophio; Pater, Joleen; Pauly, Thilo; Pearce, James; Pearson, Benjamin; Pedersen, Lars Egholm; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Penc, Ondrej; Peng, Cong; Peng, Haiping; Penwell, John; Peralva, Bernardo; Perego, Marta Maria; Perepelitsa, Dennis; Perini, Laura; Pernegger, Heinz; Perrella, Sabrina; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petroff, Pierre; Petrolo, Emilio; Petrov, Mariyan; Petrucci, Fabrizio; Pettersson, Nora Emilia; Peyaud, Alan; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Pickering, Mark Andrew; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pin, Arnaud Willy J; Pinamonti, Michele; Pinfold, James; Pirumov, Hayk; Pitt, Michael; Plazak, Lukas; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Pluth, Daniel; Podberezko, Pavel; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Polesello, Giacomo; Poley, Anne-luise; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Poppleton, Alan; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozo Astigarraga, Mikel Eukeni; Pralavorio, Pascal; Pranko, Aliaksandr; Prell, Soeren; Price, Darren; Price, Lawrence; Primavera, Margherita; Prince, Sebastien; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Puddu, Daniele; Puri, Akshat; Puzo, Patrick; Qian, Jianming; Qin, Gang; Qin, Yang; Quadt, Arnulf; Quayle, William; Queitsch-Maitland, Michaela; Quilty, Donnchadha; Raddum, Silje; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Raine, John Andrew; Rajagopalan, Srinivasan; Rangel-Smith, Camila; Ratti, Maria Giulia; Rauch, Daniel; Rauscher, Felix; Rave, Stefan; Ravenscroft, Thomas; Ravinovich, Ilia; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Reale, Marilea; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reed, Robert; Reeves, Kendall; Rehnisch, Laura; Reichert, Joseph; Reiss, Andreas; Rembser, Christoph; Ren, Huan; Rescigno, Marco; Resconi, Silvia; Resseguie, Elodie Deborah; Rettie, Sebastien; Reynolds, Elliot; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter, Stefan; Richter-Was, Elzbieta; Ricken, Oliver; Ridel, Melissa; Rieck, Patrick; Riegel, Christian Johann; Rieger, Julia; Rifki, Othmane; Rijssenbeek, Michael; Rimoldi, Adele; Rimoldi, Marco; Rinaldi, Lorenzo; Ristić, Branislav; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Rizzi, Chiara; Roberts, Rhys Thomas; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Rodina, Yulia; Rodriguez Perez, Andrea; Rodriguez Rodriguez, Daniel; Roe, Shaun; Rogan, Christopher Sean; Røhne, Ole; Roloff, Jennifer; Romaniouk, Anatoli; Romano, Marino; Romano Saez, Silvestre Marino; Romero Adam, Elena; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Rosati, Stefano; Rosbach, Kilian; Rose, Peyton; Rosien, Nils-Arne; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Jonatan; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Russell, Heather; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryu, Soo; Ryzhov, Andrey; Rzehorz, Gerhard Ferdinand; Saavedra, Aldo; Sabato, Gabriele; Sacerdoti, Sabrina; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Saha, Puja; Sahinsoy, Merve; Saimpert, Matthias; Saito, Masahiko; Saito, Tomoyuki; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salazar Loyola, Javier Esteban; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sammel, Dirk; Sampsonidis, Dimitrios; Sánchez, Javier; Sanchez Martinez, Victoria; Sanchez Pineda, Arturo Rodolfo; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Christian Oliver; Sandhoff, Marisa; Sandoval, Carlos; Sankey, Dave; Sannino, Mario; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sasaki, Osamu; Sato, Koji; Sauvan, Emmanuel; Savage, Graham; Savard, Pierre; Savic, Natascha; Sawyer, Craig; Sawyer, Lee; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Scarfone, Valerio; Schaarschmidt, Jana; Schacht, Peter; Schachtner, Balthasar Maria; Schaefer, Douglas; Schaefer, Leigh; Schaefer, Ralph; Schaeffer, Jan; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Schiavi, Carlo; Schier, Sheena; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmidt-Sommerfeld, Korbinian Ralf; Schmieden, Kristof; Schmitt, Christian; Schmitt, Stefan; Schmitz, Simon; Schneider, Basil; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schopf, Elisabeth; Schott, Matthias; Schouwenberg, Jeroen; Schovancova, Jaroslava; Schramm, Steven; Schuh, Natascha; Schulte, Alexandra; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schweiger, Hansdieter; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Sciolla, Gabriella; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Seema, Pienpen; Seidel, Sally; Seiden, Abraham; Seixas, José; Sekhniaidze, Givi; Sekhon, Karishma; Sekula, Stephen; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Sessa, Marco; Seuster, Rolf; Severini, Horst; Sfiligoj, Tina; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shaikh, Nabila Wahab; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shaw, Savanna Marie; Shcherbakova, Anna; Shehu, Ciwake Yusufu; Shen, Yu-Ting; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shirabe, Shohei; Shiyakova, Mariya; Shlomi, Jonathan; Shmeleva, Alevtina; Shoaleh Saadi, Diane; Shochet, Mel; Shojaii, Seyed Ruhollah; Shope, David Richard; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sickles, Anne Marie; Sidebo, Per Edvin; Sideras Haddad, Elias; Sidiropoulou, Ourania; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, José; Silverstein, Samuel; Simak, Vladislav; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simon, Manuel; Sinervo, Pekka; Sinev, Nikolai; Sioli, Maximiliano; Siragusa, Giovanni; Siral, Ismet; Sivoklokov, Serguei; Sjölin, Jörgen; Skinner, Malcolm Bruce; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Slawinska, Magdalena; Sliwa, Krzysztof; Slovak, Radim; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smiesko, Juraj; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Joshua Wyatt; Smith, Matthew; Smith, Russell; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snyder, Ian Michael; Snyder, Scott; Sobie, Randall; Socher, Felix; Soffer, Abner; Soh, Dart-yin; Sokhrannyi, Grygorii; Solans Sanchez, Carlos; Solar, Michael; Soldatov, Evgeny; Soldevila, Urmila; Solodkov, Alexander; Soloshenko, Alexei; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Son, Hyungsuk; Song, Hong Ye; Sopczak, Andre; Sorin, Veronica; Sosa, David; Sotiropoulou, Calliope Louisa; Soualah, Rachik; Soukharev, Andrey; South, David; Sowden, Benjamin; Spagnolo, Stefania; Spalla, Margherita; Spangenberg, Martin; Spanò, Francesco; Sperlich, Dennis; Spettel, Fabian; Spieker, Thomas Malte; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spousta, Martin; St Denis, Richard Dante; Stabile, Alberto; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Giordon; Stark, Jan; Stark, Simon Holm; Staroba, Pavel; Starovoitov, Pavel; Stärz, Steffen; Staszewski, Rafal; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strubig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Suchek, Stanislav; Sugaya, Yorihito; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Suruliz, Kerim; Suster, Carl; Sutton, Mark; Suzuki, Shota; Svatos, Michal; Swiatlowski, Maximilian; Swift, Stewart Patrick; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tanaka, Junichi; Tanaka, Masahiro; Tanaka, Reisaburo; Tanaka, Shuji; Tanioka, Ryo; Tannenwald, Benjamin Bordy; Tapia Araya, Sebastian; Tapprogge, Stefan; Tarem, Shlomit; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Aaron; Taylor, Geoffrey; Taylor, Pierre Thor Elliot; Taylor, Wendy; Teixeira-Dias, Pedro; Temming, Kim Katrin; Temple, Darren; Ten Kate, Herman; Teng, Ping-Kun; Teoh, Jia Jian; Tepel, Fabian-Phillipp; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Theveneaux-Pelzer, Timothée; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Paul; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Tibbetts, Mark James; Ticse Torres, Royer Edson; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tipton, Paul; Tisserant, Sylvain; Todome, Kazuki; Todorova-Nova, Sharka; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tolley, Emma; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Baojia(Tony); Tornambe, Peter; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Treado, Colleen Jennifer; Trefzger, Thomas; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocmé, Benjamin; Trofymov, Artur; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; Truong, Loan; Trzebinski, Maciej; Trzupek, Adam; Tsang, Ka Wa; Tseng, Jeffrey; Tsiareshka, Pavel; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsui, Ka Ming; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tu, Yanjun; Tudorache, Alexandra; Tudorache, Valentina; Tulbure, Traian Tiberiu; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turgeman, Daniel; Turk Cakir, Ilkay; Turra, Ruggero; Tuts, Michael; Ucchielli, Giulia; Ueda, Ikuo; Ughetto, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Unverdorben, Christopher; Urban, Jozef; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Usui, Junya; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valderanis, Chrysostomos; Valdes Santurio, Eduardo; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Vallier, Alexis; Valls Ferrer, Juan Antonio; Van Den Wollenberg, Wouter; van der Graaf, Harry; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vankov, Peter; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varni, Carlo; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vasquez, Jared Gregory; Vasquez, Gerardo; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veeraraghavan, Venkatesh; Veloce, Laurelle Maria; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vetterli, Michel; Viaux Maira, Nicolas; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigani, Luigi; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Vishwakarma, Akanksha; Vittori, Camilla; Vivarelli, Iacopo; Vlachos, Sotirios; Vlasak, Michal; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Peter; Wagner, Wolfgang; Wahlberg, Hernan; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wallangen, Veronica; Wang, Chao; Wang, Chao; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Qing; Wang, Rui; Wang, Song-Ming; Wang, Tingting; Wang, Wei; Wang, Wenxiao; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Washbrook, Andrew; Watkins, Peter; Watson, Alan; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Aaron Foley; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Weber, Stephen; Webster, Jordan S; Weidberg, Anthony; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Michael David; Werner, Per; Wessels, Martin; Whalen, Kathleen; Whallon, Nikola Lazar; Wharton, Andrew Mark; White, Andrew; White, Martin; White, Ryan; Whiteson, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wildauer, Andreas; Wilk, Fabian; Wilkens, Henric George; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, John; Wingerter-Seez, Isabelle; Winklmeier, Frank; Winston, Oliver James; Winter, Benedict Tobias; Wittgen, Matthias; Wobisch, Markus; Wolf, Tim Michael Heinz; Wolff, Robert; Wolter, Marcin Wladyslaw; Wolters, Helmut; Worm, Steven; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wu, Miles; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xi, Zhaoxu; Xia, Ligang; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yamaguchi, Daiki; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Shimpei; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Yi; Yang, Zongchang; Yao, Weiming; Yap, Yee Chinn; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yildirim, Eda; Yorita, Kohei; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yuen, Stephanie P; Yusuff, Imran; Zabinski, Bartlomiej; Zacharis, Georgios; Zaidan, Remi; Zaitsev, Alexander; Zakharchuk, Nataliia; Zalieckas, Justas; Zaman, Aungshuman; Zambito, Stefano; Zanzi, Daniele; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zeng, Jian Cong; Zeng, Qi; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Guangyi; Zhang, Huijun; Zhang, Jinlong; Zhang, Lei; Zhang, Liqing; Zhang, Matt; Zhang, Rui; Zhang, Ruiqi; Zhang, Xueyao; Zhang, Yu; Zhang, Zhiqing; Zhao, Xiandong; Zhao, Yongke; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Chen; Zhou, Li; Zhou, Maosen; Zhou, Mingliang; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhukov, Konstantin; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Stephanie; Zinonos, Zinonas; Zinser, Markus; Ziolkowski, Michael; Živković, Lidija; Zobernig, Georg; Zoccoli, Antonio; Zou, Rui; zur Nedden, Martin; Zwalinski, Lukasz

    2017-01-01

    The tracking performance parameters of the ATLAS Transition Radiation Tracker (TRT) as part of the ATLAS inner detector are described in this paper for different data-taking conditions in proton--proton, proton--lead and lead--lead collisions at the Large Hadron Collider (LHC). The performance is studied using data collected for different data-taking conditions in proton--proton, proton--lead and lead--lead collisions at the Large Hadron Collider (LHC). The performance is studied using data collected during the first period of LHC operation (Run 1) and is compared with Monte Carlo simulations. The performance of the TRT, operating with two different gas mixtures (xenon-based and argon-based) and its dependence on the TRT occupancy is presented. These studies show that the tracking performance of the TRT is similar for the two gas mixtures and that a significant contribution to the particle momentum resolution is made by the TRT up to high particle densities.

  1. $W$ mass measurement and simulation of the transition radiation tracker at the ATLAS experiment

    CERN Document Server

    Klinkby, Esben Bryndt

    2008-01-01

    At the time of writing, the final preparation toward LHC startup is ongoing. All the magnets of the machine have been installed and are currently being cooled. Most sub-detectors of the four experiments situated at the LHC ring are installed in their final positions and are being integrated into their respective data acquisition systems. This thesis concerns itself with the ATLAS experiment, focusing on a sub-detector called the Transition Radiation Tracker (TRT). Some attention is given to the hardware testing of the detector modules, but the main focus lies on the simulation of the detector and the comparison of the simulation with test-beam data, as well as with data collected during the commissioning phase using cosmic muons. There is little doubt that LHC will bring insight with respect to the understanding of the universe on the fundamental level. In particular, it is anticipated that light will be shed on the origin of mass which according to our current understanding proceeds via the Higgs mechanism. ...

  2. Single-cycle Terahertz Pulses with >0.2 V/A Field Amplitudes via Coherent Transition Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Daranciang, Dan; /Stanford U., Chem. Dept.; Goodfellow, John; /Stanford U. Materials Sci. Dept.; Fuchs, Matthias; /SIMES, Stanford /SLAC, PULSE; Wen, Haidan; /ANL, APS; Ghimire, Shambhu; /SLAC, PULSE; Reis, David A.; /SIMES, Sanford /SLAC, PULSE /Stanford U., Appl. Phys. Dept.; Loos, Henrik; Fisher, Alan S.; /SLAC, LCLS; Lindenberg, Aaron M.; /Stanford U. Materials Sci. Dept. /SIMES, Stanford /SLAC, PULSE

    2012-02-15

    We demonstrate terahertz pulses with field amplitudes exceeding 0.2 V/{angstrom} generated by coherent transition radiation. Femtosecond, relativistic electron bunches generated at the Linac Coherent Light Source are passed through a beryllium foil, and the emitted radiation is characterized as a function of the bunch duration and charge. Broadband pulses centered at a frequency of 10 THz with energies of 140 {mu}J are measured. These far-below-bandgap pulses drive a nonlinear optical response in a silicon photodiode, with which we perform nonlinear autocorrelations that yield information regarding the terahertz temporal profile. Simulations of the spatiotemporal profile agree well with experimental results.

  3. Partial radiative strength functions for dipole transitions in the sup 4 sup 9 sup , sup 5 sup 1 V nuclei

    CERN Document Server

    Fedorets, I D

    2002-01-01

    Radiative strength functions for dipole transitions from the compound-nuclei states to excited states of the sup 4 sup 9 V and sup 5 sup 1 V nuclei are determined from the resonance-averaged intensities of primary gamma-rays in the (p, gamma) reaction measured in the proton energy range of 1.5-3.5 MeV. The data so obtained are compared with predictions of various models. The best description for E1 transitions is achieved on the base of the model accounting for the dependence of the strength function on the gamma-ray energy, temperature, and nuclear shell structure

  4. Development of a transition radiation detector and reconstruction of photon conversions in the CBM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Klein-Boesing, Melanie

    2009-07-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. In addition, the usage of the TRD in the measurement of direct photons is investigated. CBM will be a fixed-target heavy-ion experiment, which investigates collisions in the beam energy range of 5-35 AGeV and aims to investigate the regime of high baryon densities where the phase transition is expected to be of first order. It will be a multipurpose experiment with the ability to measure leptons, hadrons, and photons. Therein, a TRD will provide the electron identification and - together with a Silicon Tracking System (STS) - the tracking of charged particles. In conjunction with a ring imaging Cherenkov (RICH) detector and a time-of-flight (TOF) measurement, the TRD is to provide a sufficient electron identification for the measurements of charmonium and low-mass vector mesons. For the TRD, the required pion suppression is a factor of about 100 at 90% electron efficiency, and the position resolution has to be of the order of 300 to 500 um. Moreover, the material budget in terms of radiation length has to be kept at a minimum in order to minimize multiple scattering and conversions which would limit the precise measurement in following TRD stations and other detectors. The largest and up to now unrivaled challenge for the TRD design is that both (PID and tracking) have to be fulfilled in the context of very high particle rates (event rates of up to 10MHz are envisaged) and at the same time large charged-particle multiplicities of up to 600 per event in the CBM detector acceptance. Small prototypes of the TRD based on multiwire proportional chambers (MWPC) with pad readout were developed and tested. The tracking performance and the electron-pion separation were determined for particle rates of up to 200 kHz/cm{sup 2}. The TRD layout and the detector

  5. Charged particle spectra measured during the transit to Mars with the Mars Science Laboratory Radiation Assessment Detector (MSL/RAD).

    Science.gov (United States)

    Ehresmann, Bent; Hassler, Donald M; Zeitlin, Cary; Guo, Jingnan; Köhler, Jan; Wimmer-Schweingruber, Robert F; Appel, Jan K; Brinza, David E; Rafkin, Scot C R; Böttcher, Stephan I; Burmeister, Sönke; Lohf, Henning; Martin, Cesar; Böhm, Eckart; Matthiä, Daniel; Reitz, Günther

    2016-08-01

    The Mars Science Laboratory (MSL) started its 253-day cruise to Mars on November 26, 2011. During cruise the Radiation Assessment Detector (RAD), situated on board the Curiosity rover, conducted measurements of the energetic-particle radiation environment inside the spacecraft. This environment consists mainly of galactic cosmic rays (GCRs), as well as secondary particles created by interactions of these GCRs with the spacecraft. The RAD measurements can serve as a proxy for the radiation environment a human crew would encounter during a transit to Mars, for a given part of the solar cycle, assuming that a crewed vehicle would have comparable shielding. The measurements of radiological quantities made by RAD are important in themselves, and, the same data set allow for detailed analysis of GCR-induced particle spectra inside the spacecraft. This provides important inputs for the evaluation of current transport models used to model the free-space (and spacecraft) radiation environment for different spacecraft shielding and different times in the solar cycle. Changes in these conditions can lead to significantly different radiation fields and, thus, potential health risks, emphasizing the need for validated transport codes. Here, we present the first measurements of charged particle fluxes inside a spacecraft during the transit from Earth to Mars. Using data obtained during the last two month of the cruise to Mars (June 11-July 14, 2012), we have derived detailed energy spectra for low-Z particles stopping in the instrument's detectors, as well as integral fluxes for penetrating particles with higher energies. Furthermore, we analyze the temporal changes in measured proton fluxes during quiet solar periods (i.e., when no solar energetic particle events occurred) over the duration of the transit (December 9, 2011-July 14, 2012) and correlate them with changing heliospheric conditions.

  6. Charged particle spectra measured during the transit to Mars with the Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)

    Science.gov (United States)

    Ehresmann, Bent; Hassler, Donald M.; Zeitlin, Cary; Guo, Jingnan; Köhler, Jan; Wimmer-Schweingruber, Robert F.; Appel, Jan K.; Brinza, David E.; Rafkin, Scot C. R.; Böttcher, Stephan I.; Burmeister, Sönke; Lohf, Henning; Martin, Cesar; Böhm, Eckart; Matthiä, Daniel; Reitz, Günther

    2016-08-01

    The Mars Science Laboratory (MSL) started its 253-day cruise to Mars on November 26, 2011. During cruise the Radiation Assessment Detector (RAD), situated on board the Curiosity rover, conducted measurements of the energetic-particle radiation environment inside the spacecraft. This environment consists mainly of galactic cosmic rays (GCRs), as well as secondary particles created by interactions of these GCRs with the spacecraft. The RAD measurements can serve as a proxy for the radiation environment a human crew would encounter during a transit to Mars, for a given part of the solar cycle, assuming that a crewed vehicle would have comparable shielding. The measurements of radiological quantities made by RAD are important in themselves, and, the same data set allow for detailed analysis of GCR-induced particle spectra inside the spacecraft. This provides important inputs for the evaluation of current transport models used to model the free-space (and spacecraft) radiation environment for different spacecraft shielding and different times in the solar cycle. Changes in these conditions can lead to significantly different radiation fields and, thus, potential health risks, emphasizing the need for validated transport codes. Here, we present the first measurements of charged particle fluxes inside a spacecraft during the transit from Earth to Mars. Using data obtained during the last two month of the cruise to Mars (June 11-July 14, 2012), we have derived detailed energy spectra for low-Z particles stopping in the instrument's detectors, as well as integral fluxes for penetrating particles with higher energies. Furthermore, we analyze the temporal changes in measured proton fluxes during quiet solar periods (i.e., when no solar energetic particle events occurred) over the duration of the transit (December 9, 2011-July 14, 2012) and correlate them with changing heliospheric conditions.

  7. Damage induced by pulsed IR laser radiation at transitions between different tissues

    Science.gov (United States)

    Frenz, Martin; Greber, Charlotte M.; Romano, Valerio; Forrer, Martin; Weber, Heinz P.

    1991-06-01

    Due to their strong absorption in water IR-lasers are excellent sources for precision cutting with minimal thermal damage in various fields of medicine. To understand the laser tissue interaction process one has to take into account the liquefaction of target material at the region of radiation impact. The dynamics of the created liquid may cause unexpected and undesirable effects for surgical laser applications. We studied the thermal damage along the walls of incision craters in terms of the elastic material properties and the dynamics of the drilling process. We show that the extension of thermally altered tissue is strongly influenced by the amount of hot liquefied tissue material remaining in the crater. When drilling into mechanically homogeneous materials this amount is essentially determined by the laser intensity used. However, when drilling through a composite structure consisting of various tissue types with different material properties, this is no longer the case. Even at low intensities, the damage zone varies substantially between the different layers. In our investigations we compared histologically and ultrastructurally the instantaneously created damage in the connective tissue and the subjacent skeletal muscle of skin after laser cutting, with long-time heating injuries. This comparison allows a differentiation between thermal and mechanical damage and an estimation of the minimum temperature created in the crater during the laser impact. The light microscopical examinations shows that the thermal damage in the connective tissue is about three times smaller than in the subjacent muscle layer. Comparative studies made with a composite structure consisting of the tissue substitutes gelatin and agar reveal that the unexpectedly large damage in the skeletal muscle layer is a result of the abrupt change of the elastic properties at the material transition. This discontinuity changes the ejection dynamics leading to a confinement of hot liquefied

  8. A MONOLITHIC PREAMPLIFIER-SHAPER FOR MEASUREMENT LOSS AND TRANSITION RADIATION.

    Energy Technology Data Exchange (ETDEWEB)

    KANDASAMY,A.

    1999-11-08

    A custom monolithic circuit has been developed for the Time Expansion Chamber (TEC) of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). This detector identifies particles by sampling their ionization energy loss (dE/dx) over a 3 cm drift space and by detecting associated transition radiation (TR) photons. The requirement of being simultaneously sensitive to dE/dx and TR events requires a dual-gain system. We have developed a compact solution featuring an octal preamplifier/shaper (P/S) IC with a split gain stage. The circuit, fabricated in 1.2 {micro}m CMOS process, incorporates a trans-impedance preamplifier and a 70 ns unipolar CR-RC{sup 4} shaper with ion tail compensation and active DC offset cancellation. Digitally selectable gain, peaking time, and tail cancellation as well as channel-by-channel charge injection and disable can be configured in the system via a 3-wire interface. The 3.5 x 5 mm{sup 2} die is packaged in a fine-pitch 64-pin PQFP. Equivalent input noise is less than 1500 rms electrons at a power dissipation of 30 mW per channel. On a sample of 2400 chips, the DC offset was 2.3 {+-} 3 mV rms without trimming. A chamber-mounted TEC-PS Printed Circuit Board (PCB) houses four PIS chips, on-board calibration circuit, and 64 analog differential line drivers which transmit the shaped pulses to crate-mounted flash ADC's. 7 m apart An RS-422 link provides digital configuration downloading and read back, and supplies the calibration strobe. The 24.6 cm x 9.5 cm board dissipates 8.5 W.

  9. A Concept for z-Dependent Microbunching Measurements with Coherent X-ray Transition Radiation in a SASE FEL

    CERN Document Server

    Lumpkin, Alex H

    2004-01-01

    Previously, measurements in the visible to VUV regimes of z-dependent microbunching in a self-amplified spontaneous emission (SASE) free-electron laser (FEL) have provided important information about the fundamental mechanisms. In those experiments a thin metal foil was used to block the more intense SASE radiation and to generate coherent optical transition radiation (COTR) as one source in a two-foil interferometer. However, for the proposed Linac Coherent Light Source (LCLS), the intense SASE emission is either too strongly transmitted at 1.5 angstroms or the needed foil thickness for blocking scatters the electron beam too much. Since coherent x-ray transition radiation (CXTR) is emitted in an annulus with opening angle 1/γ = 36 µrad for 14.09-GeV electrons, one could use a thin foil or foil stack to generate the XTR and CXTR and an annular crystal to wavelength sort the radiation. The combined selectivity will favor the CXTR over SASE by about eight orders of magnitude. Time-dependent GINGER si...

  10. Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory.

    Science.gov (United States)

    Zeitlin, C; Hassler, D M; Cucinotta, F A; Ehresmann, B; Wimmer-Schweingruber, R F; Brinza, D E; Kang, S; Weigle, G; Böttcher, S; Böhm, E; Burmeister, S; Guo, J; Köhler, J; Martin, C; Posner, A; Rafkin, S; Reitz, G

    2013-05-31

    The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011, and for most of the 253-day, 560-million-kilometer cruise to Mars, the Radiation Assessment Detector made detailed measurements of the energetic particle radiation environment inside the spacecraft. These data provide insights into the radiation hazards that would be associated with a human mission to Mars. We report measurements of the radiation dose, dose equivalent, and linear energy transfer spectra. The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert.

  11. Regulatory T Cells Promote β-Catenin–Mediated Epithelium-to-Mesenchyme Transition During Radiation-Induced Pulmonary Fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Shanshan; Pan, Xiujie; Xu, Long; Yang, Zhihua [Beijing Institute of Radiation Medicine, Beijing (China); Guo, Renfeng [Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan (United States); Gu, Yongqing; Li, Ruoxi; Wang, Qianjun; Xiao, Fengjun; Du, Li; Zhou, Pingkun [Beijing Institute of Radiation Medicine, Beijing (China); Zhu, Maoxiang, E-mail: zhumx@nic.bmi.ac.cn [Beijing Institute of Radiation Medicine, Beijing (China)

    2015-10-01

    Purpose: Radiation-induced pulmonary fibrosis results from thoracic radiation therapy and severely limits radiation therapy approaches. CD4{sup +}CD25{sup +}FoxP3{sup +} regulatory T cells (Tregs) as well as epithelium-to-mesenchyme transition (EMT) cells are involved in pulmonary fibrosis induced by multiple factors. However, the mechanisms of Tregs and EMT cells in irradiation-induced pulmonary fibrosis remain unclear. In the present study, we investigated the influence of Tregs on EMT in radiation-induced pulmonary fibrosis. Methods and Materials: Mice thoraxes were irradiated (20 Gy), and Tregs were depleted by intraperitoneal injection of a monoclonal anti-CD25 antibody 2 hours after irradiation and every 7 days thereafter. Mice were treated on days 3, 7, and 14 and 1, 3, and 6 months post irradiation. The effectiveness of Treg depletion was assayed via flow cytometry. EMT and β-catenin in lung tissues were detected by immunohistochemistry. Tregs isolated from murine spleens were cultured with mouse lung epithelial (MLE) 12 cells, and short interfering RNA (siRNA) knockdown of β-catenin in MLE 12 cells was used to explore the effects of Tregs on EMT and β-catenin via flow cytometry and Western blotting. Results: Anti-CD25 antibody treatment depleted Tregs efficiently, attenuated the process of radiation-induced pulmonary fibrosis, hindered EMT, and reduced β-catenin accumulation in lung epithelial cells in vivo. The coculture of Tregs with irradiated MLE 12 cells showed that Tregs could promote EMT in MLE 12 cells and that the effect of Tregs on EMT was partially abrogated by β-catenin knockdown in vitro. Conclusions: Tregs can promote EMT in accelerating radiation-induced pulmonary fibrosis. This process is partially mediated through β-catenin. Our study suggests a new mechanism for EMT, promoted by Tregs, that accelerates radiation-induced pulmonary fibrosis.

  12. Exploring Rotations Due to Radiation Pressure: 2-D to 3-D Transition Is Interesting!

    Science.gov (United States)

    Waxman, Michael A.

    2010-01-01

    Radiation pressure is an important topic within a standard physics course (see, in particular, Refs. 1 and 2). The physics of radiation pressure is described, the magnitude of it is derived, both for the case of a perfectly absorbing surface and of a perfect reflector, and various applications of this interesting effect are discussed, such as…

  13. ATLAS Transition Radiation Tracker (TRT): Straw Tubes for Tracking and Particle Identification at the Large Hadron Collider

    CERN Document Server

    Mindur, Bartosz; The ATLAS collaboration

    2016-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three inner detector tracking subsystems and consists of 300000 thin-walled drift tubes (“straw tubes”) that are 4 mm in diameter. The TRT system provides 30 space points with 130 micron resolution for charged tracks with |η| 0.5 GeV/c. The TRT also provides electron identification capability by detecting transition radiation (TR) X-ray photons in a Xe-based working gas mixture. Compared to Run 1, the LHC beams now provide a higher center of mass energy (13 TeV), more bunches with a reduced spacing (25 ns), and more particles in each bunch leading to very challenging, higher occupancies in the TRT. We will present TRT modifications made for Run 2 for in areas: to improve response to the expected much higher rate of hits and to mitigate leaks of the Xe-based active gas mixture. The higher rates required changes to the data acquisition system and introduction of validity gate to reject out-of-time hits. Radiation-induced gain changes in ...

  14. Impact of AMS-02 Measurements on Reducing GCR Model Uncertainties

    Science.gov (United States)

    Slaba, T. C.; O'Neill, P. M.; Golge, S.; Norbury, J. W.

    2015-01-01

    For vehicle design, shield optimization, mission planning, and astronaut risk assessment, the exposure from galactic cosmic rays (GCR) poses a significant and complex problem both in low Earth orbit and in deep space. To address this problem, various computational tools have been developed to quantify the exposure and risk in a wide range of scenarios. Generally, the tool used to describe the ambient GCR environment provides the input into subsequent computational tools and is therefore a critical component of end-to-end procedures. Over the past few years, several researchers have independently and very carefully compared some of the widely used GCR models to more rigorously characterize model differences and quantify uncertainties. All of the GCR models studied rely heavily on calibrating to available near-Earth measurements of GCR particle energy spectra, typically over restricted energy regions and short time periods. In this work, we first review recent sensitivity studies quantifying the ions and energies in the ambient GCR environment of greatest importance to exposure quantities behind shielding. Currently available measurements used to calibrate and validate GCR models are also summarized within this context. It is shown that the AMS-II measurements will fill a critically important gap in the measurement database. The emergence of AMS-II measurements also provides a unique opportunity to validate existing models against measurements that were not used to calibrate free parameters in the empirical descriptions. Discussion is given regarding rigorous approaches to implement the independent validation efforts, followed by recalibration of empirical parameters.

  15. Electron and Positron solar modulation and prediction for AMS-02

    CERN Document Server

    Bobik, P; Consolandi, C; Della Torre, S; Gervasi, M; Grandi, D; Kudela, K; Pensotti, S; Rancoita, P G

    2011-01-01

    The solar modulation, a combination of diffusion, convection, magnetic drift and energy loss inside the heliosphere is usually seen as a depletion in the Galactic cosmic ray (CR) flux at low energy (less than 10 GeV/nuc). Antiparticles such as antiprotons or positrons undergo the same processes of respective particles but with a different magnitude depending on the Solar magnetic field polarity. For electrons and positrons, due to the small mass, energy loss mechanisms as inverse compton, synchrotron, bremsstrahlung and ionization have to be taken into account, together with the typical adiabatic losses considered in the heliosphere. We developed a Monte Carlo stochastic simulation with the aim to compare the solar modulation of particles and antiparticles in the same observation period. We are able to estimate the different behaviours associated to the charge sign dependent processes of the heliospheric modulation. We compared the simulated positron fraction with measurements performed by AMS-01 and PAMELA. ...

  16. Preparation of solid-state samples of a transition metal coordination compound for synchrotron radiation photoemission studies

    CERN Document Server

    Crotti, C; Celestino, T; Fontana, S

    2003-01-01

    The aim of this research was to identify a sample preparation method suitable for the study of transition metal complexes by photoemission spectroscopy with synchrotron radiation as the X-ray source, even in the case where the compound is not evaporable. Solid-phase samples of W(CO) sub 4 (dppe) [dppe=1,2-bis(diphenylphosphino)ethane] were prepared according to different methods and their synchrotron radiation XPS spectra measured. The spectra acquired from samples prepared by spin coating show core level peaks only slightly broader than the spectrum recorded from UHV evaporated samples. Moreover, for these samples the reproducibility of the binding energy values is excellent. The dependence of the spin coating technique on parameters such as solvent and solution concentration, spinning speed and support material was studied. The same preparation method also allowed the acquisition of valence band spectra, the main peaks of which were clearly resolved. The results suggest that use of the spin coating techniqu...

  17. Energy levels, radiative rates and lifetimes for transitions in Br-like ions with 38 $\\le$ Z $\\le$ 42

    CERN Document Server

    Aggarwal, K M

    2014-01-01

    Energy levels and radiative rates for transitions in five Br-like ions (Sr IV, Y V, Zr VI, Nb VII and Mo VIII) are calculated with the general-purpose relativistic atomic structure package ({\\sc grasp}). Extensive configuration interaction has been included and results are presented among the lowest 31 levels of the 4s$^2$4p$^5$, 4s$^2$4p$^4$4d and 4s4p$^6$ configurations. Lifetimes for these levels have also been determined, although unfortunately no measurements are available with which to compare. However, recently theoretical results have been reported by Singh {\\em et al} [Phys. Scr. {\\bf 88} (2013) 035301] using the same {\\sc grasp} code. But their reported data for radiative rates and lifetimes cannot be reproduced and show discrepancies of up to five orders of magnitude with the present calculations.

  18. Performance of the transition radiation detector flown on the NMSU/WIZARD TS93 balloon-borne instrument

    Energy Technology Data Exchange (ETDEWEB)

    Aversa, F.; Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy). Dip. di Fisica]|[INFN, Trieste (Italy); Basini, G.; Brancaccio, F.M. [INFN, Laboratori nazionali di Frascati, Frascati, Rome (Italy); Bellotti, R. [Bari Univ. (Italy). Dip. di Fisica]|[INFN, Bari (Italy); Bidoli, V. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Bocciolini, M. [Florence Univ. (Italy). Dip. di Fisica]|[INFN, Florence (Italy); Bronzini, F. [Rome Univ. `La Sapienza` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `La Sapienza` Rome (Italy)

    1995-09-01

    It is built and tested a transition radiation detector (TRD) to discriminate positrons from protons in the balloon flight TS 93 experiment. It is presented the TRD performance using flight data obtaining a proton-positron rejection factor of the order of 10{sup -3}. During the 24 hour flight, the data in the momentum range 4-50 GeV/c are collected. Using the TRD together with the Silicon calorimeter, it is achieved an overall rejection factor of about 10{sup -5} of positron against the proton background over the entire momentum range.

  19. Laer Pulse Driven THz Generation via Resonant Transition Radiation in Inhomogeneous Plasmas

    CERN Document Server

    Miao, Chenlong; Antonsen, Thomas M

    2016-01-01

    An intense, short laser pulse propagating across a plasma boundary ponderomotively drives THz radiation. Full format PIC simulations and theoretical analysis are conducted to investigate the properties of this radiation. Simulation results show the THz emission originates in regions of varying density and covers a broad spectrum with maximum frequency close to the maximum plasma frequency. In the case of a sharp vacuum-plasma boundary, the radiation is generated symmetrically at the plasma entrance and exit, and its properties are independent of plasma density when the density exceeds a characteristic value determined by the product of the plasma frequency and the laser pulse duration. For a diffuse vacuum-plasma boundary, the emission from the plasma entrance and exit is asymmetric: increasing and decreasing density ramps enhance and diminish the radiated energy respectively. Enhancements by factors of 50 are found and simulations show that a 1.66 J, 50 fs driver pulse can generate ~400 \\mu J of THz radiatio...

  20. Electronic transition dipole moment and radiative lifetime calculations of sodium dimer ion-pair states.

    Science.gov (United States)

    Sanli, Aydin; Beser, Bediha; Edwardson, John R; Magnier, Sylvie; Ahmed, Ergin H; Marjatta Lyyra, A

    2015-09-14

    We report here ab initio calculated electronic transition dipole moments for the sodium dimer ion pair states of (1)Σg (+) symmetry. They vary strongly as a function of internuclear distance because of the effect of the Na(+) + Na(-) ion pair potential, which also causes the formation of additional wells and shoulders in the molecular potential energy curves. We also present a computational study of the transition dipole moment matrix elements and lifetimes for these ion-pair states.

  1. The FERRUM Project: experimental and theoretical transition rates of forbidden [Sc II] lines and radiative lifetimes of metastable Sc II levels

    CERN Document Server

    Hartman, H; Lundin, P; Schef, P; Hibbert, A; Lundberg, H; Mannervik, S; Norlin, L -O; Royen, P

    2008-01-01

    Context. In many plasmas, long-lived metastable atomic levels are depopulated by collisions (quenched) before they decay radiatively. In low-density regions, however, the low collision rate may allow depopulation by electric dipole (E1) forbidden radiative transitions, so-called forbidden lines (mainly M1 and E2 transitions). If the atomic transition data are known, these lines are indicators of physical plasma conditions and used for abundance determination. Aims. Transition rates can be derived by combining relative intensities between the decay channels, so-called branching fractions (BFs), and the radiative lifetime of the common upper level. We use this approach for forbidden [Sc ii] lines, along with new calculations. Methods. Neither BFs for forbidden lines, nor lifetimes of metastable levels, are easily measured in a laboratory. Therefore, astrophysical BFs measured in Space Telescope Imaging Spectrograph (STIS) spectra of the strontium filament of Eta Carinae are combined with lifetime measurements u...

  2. Performance of the ATLAS Transition Radiation Tracker With First High Energy pp and Pb-Pb Collisions

    CERN Document Server

    Vogel, A; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider at CERN. It consists of close to 300000 thin-wall drift tubes (straws) providing on average 30 two-dimensional space points with 0.12-0.15 mm resolution for charged particle tracks with |η| < 2 and pT > 0.5 GeV. Along with continuous tracking, it provides particle identification capability through the detection of transition radiation X-ray photons generated by high velocity particles in the many polymer fibers or films that fill the spaces between the straws. Custom-built analog and digital electronics is optimized to operate as luminosity increases to the LHC design. In this talk, a review of the commissioning and first operational experience of the TRT detector will be presented. Emphasis will be given to performance studies based on the reconstruction and analysis of LHC collisions. The first studies of the TRT detector response to the extremely hig...

  3. Performance of the ATLAS Transition Radiation Tracker With First High Energy pp and Pb-Pb Collisions

    CERN Document Server

    Vogel, A; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider at CERN. It consists of close to 300000 thin-wall drift tubes (straws) providing on average 30 two-dimensional space points with 0.12-0.15 mm resolution for charged particle tracks with |η| 0.5 GeV. Along with continuous tracking, it provides particle identification capability through the detection of transition radiation X-ray photons generated by high velocity particles in the many polymer fibers or films that fill the spaces between the straws. Custom-built analog and digital electronics is optimized to operate as luminosity increases to the LHC design. In this talk, a review of the commissioning and first operational experience of the TRT detector will be presented. Emphasis will be given to performance studies based on the reconstruction and analysis of LHC collisions. The first studies of the TRT detector response to the extremely high track density conditions...

  4. ATLAS Transition Radiation Tracker (TRT): Straw Tubes for Tracking and Particle Identification at the Large Hadron Collider

    CERN Document Server

    Mindur, Bartosz; The ATLAS collaboration

    2016-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three inner detector tracking subsystems and consists of $\\sim$300000 thin-walled drift tubes (``straw tubes'') that are 4~mm in diameter. The TRT system provides $\\sim$30 space points with $\\sim$130 micron resolution for charged tracks with $|\\eta| $ 0.5 GeV/c. The TRT also provides electron identification capability by detecting transition radiation (TR) X-ray photons in an Xe-based working gas mixture. Compared to Run 1, the LHC beams now provide a higher centre of mass energy (13 TeV), more bunches with a reduced spacing (25 ns), and more particles in each bunch leading to very challenging, higher occupancies in the TRT. Significant modifications of the TRT detector have been made for LHC Run 2 mainly to improve response to the expected much higher rate of hits and to mitigate leaks of the Xe-based active gas mixture. The higher rates required changes to the data acquisition system and introduction of validity gate to reject out-of-time ...

  5. ATLAS Transition Radiation Tracker (TRT): Straw tubes for tracking and particle identification at the Large Hadron Collider

    Science.gov (United States)

    Mindur, Bartosz

    2017-02-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three inner detector tracking subsystems and consists of ∼300,000 thin-walled drift tubes (;straw tubes;) that are 4 mm in diameter. The TRT system provides ∼ 30 space points with ∼130 micron resolution for charged tracks with | η | 0.5 GeV / c . The TRT also provides electron identification capability by detecting transition radiation (TR) X-ray photons in an Xe-based working gas mixture. Compared to Run 1, the LHC beams now provide a higher centre of mass energy (13 TeV), more bunches with a reduced spacing (25 ns), and more particles in each bunch leading to very challenging, higher occupancies in the TRT. Significant modifications of the TRT detector have been made for LHC Run 2 mainly to improve response to the expected much higher rate of hits and to mitigate leaks of the Xe-based active gas mixture. The higher rates required changes to the data acquisition system and introduction of validity gate to reject out-of-time hits. Many gas leaks were repaired and the gas system was modified to use a cheaper Ar-based gas mixture in some channels. A likelihood method was introduced to optimise the TRT electron identification.

  6. NUSTART: A PC code for NUclear STructure And Radiative Transition analysis and supplementation

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.L.; Gardner, D.G.; Gardner, M.A.

    1990-10-01

    NUSTART is a computer program for the IBM PC/At. It is designed for use with the nuclear reaction cross-section code STAPLUS, which is a STAPRE-based CRAY computer code that is being developed at Lawrence Livermore National Laboratory. The NUSTART code was developed to handle large sets of discrete nuclear levels and the multipole transitions among these levels; it operates in three modes. The Data File Error Analysis mode analyzes an existing STAPLUS input file containing the levels and their multipole transition branches for a number of physics and/or typographical errors. The Interactive Data File Generation mode allows the user to create input files of discrete levels and their branching fractions in the format required by STAPLUS, even though the user enters the information in the (different) format used by many people in the nuclear structure field. In the Branching Fractions Calculations mode, the discrete nuclear level set is read, and the multipole transitions among the levels are computed under one of two possible assumptions: (1) the levels have no collective character, or (2) the levels are all rotational band heads. Only E1, M1, and E2 transitions are considered, and the respective strength functions may be constants or, in the case of E1 transitions, the strength function may be energy dependent. The first option is used for nuclei closed shells; the bandhead option may be used to vary the E1, M1, and E2 strengths for interband transitions. K-quantum number selection rules may be invoked if desired. 19 refs.

  7. Radiosensitivity and capacity for radiation-induced sublethal damage repair of canine transitional cell carcinoma (TCC) cell lines.

    Science.gov (United States)

    Parfitt, S L; Milner, R J; Salute, M E; Hintenlang, D E; Farese, J P; Bacon, N J; Bova, F J; Rajon, D A; Lurie, D M

    2011-09-01

    Understanding the inherent radiosensitivity and repair capacity of canine transitional cell carcinoma (TCC) can aid in optimizing radiation protocols to treat this disease. The objective of this study was to evaluate the parameters surviving fraction at 2 Gy (SF(2) ), α/β ratio and capacity for sublethal damage repair (SLDR) in response to radiation. Dose-response and split-dose studies were performed using the clonogenic assay. The mean SF(2) for three established TCC cell lines was high at 0.61. All the three cell lines exhibited a low to moderate α/β ratio, with the mean being 3.27. Two cell lines exhibited statistically increased survival at 4 and 24 h in the dose-response assay. Overall, our results indicate that the cell lines are moderately radioresistant, have a high repair capacity and behave similarly to a late-responding normal tissue. These findings indicate that the radiation protocols utilizing higher doses with less fractionation may be more effective for treating TCC.

  8. Radiation Pressure on Bacterial Clumps in the Solar Vicinity and Their Survival Between Interstellar Transits

    Science.gov (United States)

    Wickramasinghe, N. C.; Wickramasinghe, J. T.

    Radiation pressure cross-sections for clumps of hollow bacterial grains with thin coatings of graphite are calculated using rigorous Guttler formulae. The carbonized skins are expected to form through exposure to solar ultraviolet radiation, but a limiting thickness of about 0.03 μm is determined by opacity effects. The ratios of radiation pressure to gravity P/G are calculated for varying sizes of the clumps and for varying thickness of the graphite coatings. Bacterial clumps and individual desiccated bacteria without coatings of radii in the range 0.3-8 μm have P/G ratios less than unity, whereas particles with coatings of 0.02 μm thickness have ratios in excess of unity. Such coatings also provide protection from damaging ultraviolet radiation. Putative cometary bacteria, such as have been recently collected in the stratosphere, are thus not gravitationally bound in the solar system provided they possess carbonised exterior coatings. They are rapidly expelled from the solar system reaching nearby protosolar nebulae in timescales of a few million years. Even with the most pessimistic assumptions galactic cosmic rays are unable to diminish viability to an extent that vitiates the continuity of panspermia.

  9. Mathematical models of tissue stem and transit target cell divisions and the risk of radiation- or smoking-associated cancer.

    Science.gov (United States)

    Little, Mark P; Hendry, Jolyon H

    2017-02-01

    There is compelling biological data to suggest that cancer arises from a series of mutations in single target cells, resulting in defects in cell renewal and differentiation processes which lead to malignancy. Because much mutagenic damage is expressed following cell division, more-rapidly renewing tissues could be at higher risk because of the larger number of cell replications. Cairns suggested that renewing tissues may reduce cancer risk by partitioning the dividing cell populations into lineages comprising infrequently-dividing long-lived stem cells and frequently-dividing short-lived daughter transit cells. We develop generalizations of three recent cancer-induction models that account for the joint maintenance and renewal of stem and transit cells, also competing processes of partially transformed cell proliferation and differentiation/apoptosis. We are particularly interested in using these models to separately assess the probabilities of mutation and development of cancer associated with "spontaneous" processes and with those linked to a specific environmental mutagen, specifically ionizing radiation or cigarette smoking. All three models demonstrate substantial variation in cancer risks, by at least 20 orders of magnitude, depending on the assumed number of critical mutations required for cancer, and the stem-cell and transition-cell mutation rates. However, in most cases the conditional probabilities of cancer being mutagen-induced range between 7-96%. The relative risks associated with mutagen exposure compared to background rates are also stable, ranging from 1.0-16.0. Very few cancers, generally Little difference is made to relative risks if competing processes of proliferation and differentiation in the partially transformed stem and transit cell population are allowed for, nor is any difference made if one assumes that transit cells require an extra mutation to confer malignancy from the number required by stem cells. The probability of a cancer

  10. Standard Guide for Predicting Radiation-Induced Transition Temperature Shift in Reactor Vessel Materials, E706 (IIF)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This guide presents a method for predicting reference transition temperature adjustments for irradiated light-water cooled power reactor pressure vessel materials based on Charpy V-notch 30-ftlbf (41-J) data. Radiation damage calculative procedures have been developed from a statistical analysis of an irradiated material database that was available as of May 2000. The embrittlement correlation used in this guide was developed using the following variables: copper and nickel contents, irradiation temperature, and neutron fluence. The form of the model was based on current understanding for two mechanisms of embrittlement: stable matrix damage (SMD) and copper-rich precipitation (CRP); saturation of copper effects (for different weld materials) was included. This guide is applicable for the following specific materials, copper, nickel, and phosphorus contents, range of irradiation temperature, and neutron fluence based on the overall database: 1.1.1 MaterialsA 533 Type B Class 1 and 2, A302 Grade B, A302 G...

  11. Ultra-compact injection terahertz laser using the resonant inter-layer radiative transitions in multi-graphene-layer structure

    CERN Document Server

    Dubinov, Alexander A; Aleshkin, Vladimir Ya; Ryzhii, Victor; Otsuji, Taiichi; Svintsov, Dmitry

    2016-01-01

    The optimization of laser resonators represents a crucial issue for the design of terahertz semiconductor lasers with high gain and low absorption loss. In this paper, we put forward and optimize the surface plasmonic metal waveguide geometry for the recently proposed terahertz injection laser based on resonant radiative transitions between tunnel-coupled grapheme layers. We find an optimal number of active graphene layer pairs corresponding to the maximum net modal gain. The maximum gain increases with frequency and can be as large as ~ 500 cm-1 at 8 THz, while the threshold length of laser resonator can be as small as ~ 50 mkm. Our findings substantiate the possibility of ultra-compact voltage-tunable graphene-based lasers operating at room temperature.

  12. Electromagnetic transition form factor and radiative corrections in decays of neutral pions

    Directory of Open Access Journals (Sweden)

    Husek Tomáš

    2016-01-01

    Full Text Available We briefly summarize experimental and theoretical results on the rare decay π0 → e+e−. The notorious 3.3σ discrepancy between the SM prediction and the experimental value provided by KTeV collaboration is discussed in the view of a complete set of NLO QED radiative corrections. We also present the Two-Hadron Saturation (THS scenario for the PVV correlator and apply it to the decay under discussion. The discrepancy then reduces down to 1.8σ.

  13. Status of design and construction of the transition radiation tracker (TRT) for the ATLAS experiment at the LHC

    CERN Document Server

    Åkesson, T; Arik, E; Baker, O K; Baron, S; Benjamin, D; Bertelsen, H; Bondarenko, V; Bychkov, V; Callahan, J; Capéans-Garrido, M; Cardiel-Sas, L; Catinaccio, A; Cetin, S A; Cwetanski, Peter; Dam, M; Danielsson, H; Dittus, F; Dolgoshein, B A; Dressnandt, N; Driouichi, C; Ebenstein, W L; Eerola, Paule Anna Mari; Farthouat, Philippe; Fedin, O; Froidevaux, D; Gagnon, P; Grichkevitch, Y; Grigalashvili, N S; Hajduk, Z; Hansen, P; Kayumov, F; Keener, P T; Kekelidze, G D; Khristatchev, A; Konovalov, S; Koudine, L; Kovalenko, S; Kowalski, T; Kramarenko, V A; Krüger, K; Laritchev, A; Lichard, P; Luehring, F C; Lundberg, B; Maleev, V; Markina, I; McFarlane, K W; Mialkovski, V; Mindur, B; Mitsou, V A; Morozov, S; Munar, A; Muraviev, S; Nadtochy, A; Newcomer, F M; Ögren, H O; Oh, S H; Oleshko, S; Olszowska, J; Passmore, S; Patritchev, S; Peshekhonov, V D; Petti, R; Price, M; Rembser, C; Rohne, O; Romaniouk, A; Rust, D R; Ryabov, Yu; Ryzhov, V; Shchegelskii, V; Seliverstov, D M; Shin, T; Shmeleva, A; Smirnovg, S; Sosnovtsev, V V; Soutchkov, V; Spiridenkov, E; Szczygiel, R; Tikhomirov, V; Van Berg, R; Vassilakopoulos, V I; Vassilieva, L; Wange, C; Williams, H H; Zalite, A

    2004-01-01

    The ATLAS Inner Detector consists of three sub-systems, the pixel detector at the innermost radius, the semiconductor tracker at intermediate radii, and the transition radiation tracker (TRT) at the outermost radius in front of the electromagnetic calorimeter. The TRT provides a combination of continuous tracking with many projective measurements based on individual drift-tubes (or straws) and of electron identification based on radiator fibres or foils interleaved between the straws themselves. This paper describes the current status of design and construction of the various components of the TRT: the assembly of the barrel modules has recently been completed, that of the end-cap wheels is well underway, and the on-detector front-end electronics is in production. The detector modules and front-end electronics boards will be integrated together over the next year, the barrel and end-cap TRT parts will be assembled and tested with their SCT counterparts during 2005 and installation and commissioning in the ATL...

  14. Ionizing Radiation Promotes Migration and Invasion of Cancer Cells Through Transforming Growth Factor-Beta-Mediated Epithelial-Mesenchymal Transition

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yongchun [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Liu Junye; Li Jing; Zhang Jie [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Xu Yuqiao [Department of Pathology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Zhang Huawei; Qiu Lianbo; Ding Guirong [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Su Xiaoming [Department of Radiation Oncology, 306th Hospital of PLA, Beijing (China); Mei Shi [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Guo Guozhen, E-mail: guozhenguo@hotmail.com [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China)

    2011-12-01

    Purpose: To examine whether ionizing radiation enhances the migratory and invasive abilities of cancer cells through transforming growth factor (TGF-{beta})-mediated epithelial-mesenchymal transition (EMT). Methods and Materials: Six cancer cell lines originating from different human organs were irradiated by {sup 60}Co {gamma}-ray at a total dose of 2 Gy, and the changes associated with EMT, including morphology, EMT markers, migration and invasion, were observed by microscope, Western blot, immunofluorescence, scratch assay, and transwell chamber assay, respectively. Then the protein levels of TGF-{beta} in these cancer cells were detected by enzyme-linked immunosorbent assay, and the role of TGF-{beta} signaling pathway in the effect of ionizing radiation on EMT was investigate by using the specific inhibitor SB431542. Results: After irradiation with {gamma}-ray at a total dose of 2 Gy, cancer cells presented the mesenchymal phenotype, and compared with the sham-irradiation group the expression of epithelial markers was decreased and of mesenchymal markers was increased, the migratory and invasive capabilities were strengthened, and the protein levels of TGF-{beta} were enhanced. Furthermore, events associated with EMT induced by IR in A549 could be reversed through inhibition of TGF-{beta} signaling. Conclusions: These results suggest that EMT mediated by TGF-{beta} plays a critical role in IR-induced enhancing of migratory and invasive capabilities in cancer cells.

  15. Synchrotron radiation X-ray multiple diffraction in the study of KDP phase transition induced by electric field

    Directory of Open Access Journals (Sweden)

    A.O. dos Santos

    2001-01-01

    Full Text Available In this work, the application of the X-ray multiple diffraction technique using synchrotron radiation at Laboratório Nacional de Luz Síncrotron (LNLS to study KDP phase transition induced by electric field is discussed. A Huber three-axis (omega, phi, 2theta diffractometer mounted on a table which rotates around the incident beam allows to measure Renninger scans (RS at the XRD station of LNLS using the adequate polarization for the experiments. Prior results indicated (080 as the best choice for the KDP primary reflection and the (440( 40 four-beam case for the secondary. Two Bragg-surface diffraction (BSD reflections, where the secondary beam is propagated parallel to the sample surface, are involved in this multiple diffraction case. A RS interval of 3.3° around phi = 0° position was measured while the electric field was increased up to 6 kV/cm. At this value, a phase transition was observed and the secondary peaks became narrower and changed their RS position indicating possible occurrence of a metastable ferroelectric phase.

  16. Bottomonium spectroscopy and radiative transitions involving the chi_bJ(1P,2P) states at BABAR

    CERN Document Server

    Lees, J P

    2014-01-01

    We use $(121\\pm1)$ million $\\Upsilon(3S)$ and $(98\\pm1)$ million $\\Upsilon(2S)$ mesons recorded by the BABAR detector at the PEP-II $e^+e^-$ collider at SLAC to perform a study of radiative transitions involving the $\\chi_{b\\mathrm{J}}(1P,2P)$ states in exclusive decays with $\\mu^+\\mu^-\\gamma\\gamma$ final states. We reconstruct twelve channels in four cascades using two complementary methods. In the first we identify both signal photon candidates in the Electromagnetic Calorimeter (EMC), employ a calorimeter timing-based technique to reduce backgrounds, and determine branching-ratio products and fine mass splittings. These results include the best observational significance yet for the $\\chi_{b0}(2P)\\rightarrow\\gamma\\Upsilon(2S)$ and $\\chi_{b0}(1P)\\rightarrow\\gamma\\Upsilon(1S)$ transitions. In the second method, we identify one photon candidate in the EMC and one which has converted into an $e^+e^-$ pair due to interaction with detector material, and we measure absolute product branching fractions. This metho...

  17. A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

    Energy Technology Data Exchange (ETDEWEB)

    Sedlar, Joseph; Tjernstroem, Michael; Leck, Caroline [Stockholm University, Department of Meteorology, Stockholm (Sweden); Mauritsen, Thorsten [Max-Planck-Institute for Meteorology, Hamburg (Germany); Shupe, Matthew D.; Persson, P.O.G. [University of Colorado, NOAA-ESRL-PSD, Boulder, CO (United States); Brooks, Ian M.; Birch, Cathryn E. [University of Leeds, School of Earth and Environment, Leeds (United Kingdom); Sirevaag, Anders [University of Bergen, Bjerknes Center for Climate Research, Bergen (Norway); Nicolaus, Marcel [Norwegian Polar Institute, Tromsoe (Norway); Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany)

    2011-10-15

    Snow surface and sea-ice energy budgets were measured near 87.5 N during the Arctic Summer Cloud Ocean Study (ASCOS), from August to early September 2008. Surface temperature indicated four distinct temperature regimes, characterized by varying cloud, thermodynamic and solar properties. An initial warm, melt-season regime was interrupted by a 3-day cold regime where temperatures dropped from near zero to -7 C. Subsequently mean energy budget residuals remained small and near zero for 1 week until once again temperatures dropped rapidly and the energy budget residuals became negative. Energy budget transitions were dominated by the net radiative fluxes, largely controlled by the cloudiness. Variable heat, moisture and cloud distributions were associated with changing air-masses. Surface cloud radiative forcing, the net radiative effect of clouds on the surface relative to clear skies, is estimated. Shortwave cloud forcing ranged between -50 W m{sup -2} and zero and varied significantly with surface albedo, solar zenith angle and cloud liquid water. Longwave cloud forcing was larger and generally ranged between 65 and 85 W m{sup -2}, except when the cloud fraction was tenuous or contained little liquid water; thus the net effect of the clouds was to warm the surface. Both cold periods occurred under tenuous, or altogether absent, low-level clouds containing little liquid water, effectively reducing the cloud greenhouse effect. Freeze-up progression was enhanced by a combination of increasing solar zenith angles and surface albedo, while inhibited by a large, positive surface cloud forcing until a new air-mass with considerably less cloudiness advected over the experiment area. (orig.)

  18. Dark Matter and Strong Electroweak Phase Transition in a Radiative Neutrino Mass Model

    CERN Document Server

    Ahriche, Amine

    2013-01-01

    We consider an extension of the standard model (SM) with charged singlet scalars and right handed (RH) neutrinos all at the electroweak scale. In this model, the neutrino masses are generated at three loops, which provide an explanation for their smallness, and the lightest RH neutrino, $N_{1}$, is a dark matter candidate. We find that for three generations of RH neutrinos, the model can be consistent with the neutrino oscillation data, lepton flavor violating processes, $N_{1}$ can have a relic density in agreement with the recent Planck data, and the electroweak phase transition can be strongly first order. We also show that the charged scalars may enhance the branching ratio $h-->YY$, where as $h-->YZ$ get can get few percent suppression. We also discuss the phenomenological implications of the RH neutrinos at the collider.

  19. The structure of pre-transitional protoplanetary disks. I. Radiative transfer modeling of the disk+cavity in the PDS 70 system

    NARCIS (Netherlands)

    Dong, R.; Hashimoto, J.; Rafikov, R.; Zhu, Z.; Whitney, B.; Kudo, T.; Muto, T.; Brandt, T.; McClure, M.K.; Wisniewski, J.; Abe, L.; Brandner, W.; Carson, J.; Egner, S.; Feldt, M.; Goto, M.; Grady, C.; Guyon, O.; Hayano, Y.; Hayashi, M.; Hayashi, S.; Henning, T.; Hodapp, K.W.; Ishii, M.; Iye, M.; Janson, M.; Kandori, R.; Knapp, G.R.; Kusakabe, N.; Kuzuhara, M.; Kwon, J.; Matsuo, T.; McElwain, M.; Miyama, S.; Morino, J.-I.; Moro-Martin, A.; Nishimura, T.; Pyo, T.-S.; Serabyn, E.; Suto, H.; Suzuki, R.; Takami, M.; Takato, N.; Terada, H.; Thalmann, C.; Tomono, D.; Turner, E.; Watanabe, M.; Yamada, T.; Takami, H.; Usuda, T.; Tamura, M.

    2012-01-01

    Through detailed radiative transfer modeling, we present a disk+cavity model to simultaneously explain both the spectral energy distribution (SED) and Subaru H-band polarized light imaging for the pre-transitional protoplanetary disk PDS 70. In particular, we are able to match not only the radial de

  20. Chemical freeze-out in Hawking-Unruh radiation and quark-hadron transition

    CERN Document Server

    Tawfik, Abdel Nasser; Elyazeed, Eman R Abo

    2015-01-01

    The proposed analogy between hadron production in high-energy collisions and Hawking-Unruh radiation process in the black holes shall be extended. This mechanism provides a theoretical basis for the freeze-out parameters, the temperature ($T$) and the baryon chemical potential ($\\mu$), characterizing the final state of particle production. The results from charged black holes, in which the electric charge is related to $\\mu$, are found comparable with the phenomenologically deduced parameters from the ratios of various particle species and the higher-order moments of net-proton multiplicity in thermal statistical models and Polyakov linear-sigma model. Furthermore, the resulting freeze-out condition $\\langle E\\rangle/\\langle N\\rangle\\simeq 1~$GeV for average energy per particle is in good agreement with the hadronization process in the high-energy experiments. For the entropy density ($s$), the freeze-out condition $s/T^3\\simeq7$ remains valid for $\\mu\\lesssim 0.3~$GeV. Then, due to the dependence of $T$ on $...

  1. Strong Role of Non-stationary Accretion in Spectral Transitions of X-ray Binaries and Implications for Revealing the Accretion Geometry and Broadband Radiation Mechanisms

    Science.gov (United States)

    Yu, Wenfei; Yan, Zhen; Tang, Jing; Wu, Yuxiang

    Observations of spectral transitions from the hard state to the soft state in bright X-ray binaries show strong evidence that the rate-of-change of the mass accretion rate plays a dominant role in determining the luminosity at which the spectral transition occurs. This indicates that in many cases, especially accretion in transients during outbursts, the rate-of-change of the mass accretion rate is the primary parameter driving high energy phenomena. Although this goes beyond the scope of current stationary model of disk and jet, it tells us that it is the rate-of-change of the mass accretion rate that we need to trace observationally. Since state transition is a broadband phenomenon, multi-wavelength observations of spectral transitions of different rate-of-changes of mass accretion rate are expect to reveal the accretion geometry and broadband radiation mechanisms.

  2. Radiative and Pionic transitions from the $D_{s1}(2460)$ to the $D_{s0}^\\ast(2317)$

    CERN Document Server

    Xiao, cheng-Jian; Ma, Yong-Liang

    2016-01-01

    We estimate the partial widths for the radiative and pionic transitions from the $D_{s1}(2460)$ to the $D_{s0}(2317)$ in a molecule scenario, in which the $D_{s1}(2460)$ and $D_{s0}^\\ast(2317)$ are considered as hadronic molecule states of $DK$ and $D^\\ast K$, respectively. The partial widths for the $D_{s1}(2460) \\to D_{s0}^\\ast(2317) \\pi^0$ and $D_{s1}(2460) \\to D_{s0}^\\ast(2317) \\gamma$ are evaluated to be about $0.19 \\sim 0.22$ keV and $3.0 \\sim 3.1$ keV, respectively. In addition, the ratio of the $D_{s1}(2460) \\to D_{s0}(2317) \\gamma$ and $D_{s1}(2460) \\to D_{s}^\\ast \\pi^0$ is estimated to be about $(6.6\\sim 10.6) \\times 10^{-2}$, which is safely under the measured upper limit.

  3. Search for the radiative transitions $\\psi(3770)\\to\\gamma\\eta_c$ and $\\gamma\\eta_c(2S)$

    CERN Document Server

    Ablikim, M; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; An, F F; An, Q; Bai, J Z; Ferroli, R Baldini; Ban, Y; Bennett, D W; Bennett, J V; Bertani, M; Bian, J M; Boger, E; Bondarenko, O; Boyko, I; Braun, S; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Cheng, H P; Chu, X K; Chu, Y P; Cronin-Hennessy, D; Dai, H L; Dai, J P; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; Ding, W M; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Du, S X; Fan, J Z; Fang, J; Fang, S S; Fang, Y; Fava, L; Feng, C Q; Fu, C D; Fuks, O; Gao, Q; Gao, Y; Geng, C; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, L B; Guo, T; Guo, Y P; Haddadi, Z; Han, S; Han, Y L; Harris, F A; He, K L; He, M; He, Z Y; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Huang, G M; Huang, G S; Huang, H P; Huang, J S; Huang, L; Huang, X T; Huang, Y; Hussain, T; Ji, C S; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L L; Jiang, L W; Jiang, X S; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Kloss, B; Kopf, B; Kornicer, M; Kuehn, W; Kupsc, A; Lai, W; Lange, J S; Lara, M; Larin, P; Leyhe, M; Li, C H; Li, Cheng; Li, Cui; Li, D; Li, D M; Li, F; Li, G; Li, H B; Li, J C; Li, Jin; Li, K; Li, P R; Li, Q J; Li, T; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Lin, D X; Liu, B J; Liu, C L; Liu, C X; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H M; Liu, J; Liu, J P; Liu, K; Liu, K Y; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Z A; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, G R; Lu, H J; Lu, H L; Lu, J G; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lv, M; Lyu, X R; Ma, F C; Ma, H L; Ma, Q M; Ma, S; Ma, T; Ma, X Y; Maas, F E; Maggiora, M; Malik, Q A; Mao, Y J; Mao, Z P; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Mo, Y J; Moeini, H; Morales, C Morales; Moriya, K; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Pelizaeus, M; Peng, H P; Peters, K; Ping, J L; Ping, R G; Poling, R; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Y; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ripka, M; Rong, G; Ruan, X D; Sarantsev, A; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, X Y; Sheng, H Y; Shepherd, M R; Song, W M; Song, X Y; Spataro, S; Spruck, B; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Toth, D; Ullrich, M; Uman, I; Varner, G S; Wang, B; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Q J; Wang, S G; Wang, W; Wang, X F; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Wei, D H; Wei, J B; Weidenkaff, P; Wen, S P; Werner, M; Wiedner, U; Wolke, M; Wu, L H; Wu, N; Wu, Z; Xia, L G; Xia, Y; Xiao, D; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, L; Xu, Q J; Xu, Q N; Xu, X P; Xue, Z; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H X; Yang, L; Yang, Y; Yang, Y X; Ye, H; Ye, M; Ye, M H; Yu, B X; Yu, C X; Yu, H W; Yu, J S; Yu, S P; Yuan, C Z; Yuan, W L; Yuan, Y; Yuncu, A; Zafar, A A; Zallo, A; Zang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C B; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J J; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, S H; Zhang, X J; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Z H; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, X H; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, Y H; Zhong, B; Zhou, L; Zhou, Li; Zhou, X; Zhou, X K; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zou, B S; Zou, J H

    2014-01-01

    By using a 2.92 fb$^{-1}$ data sample taken at $\\sqrt{s} = 3.773$ GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions $\\psi(3770)\\to\\gamma\\eta_c$ and $\\gamma\\eta_c(2S)$ through the hadronic decays $\\eta_c(\\eta_c(2S))\\to K^0_SK^\\pm\\pi^\\mp$. No significant excess of signal events above background is observed. We set upper limits at a 90% confidence level for the product branching fractions to be $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c)\\times \\mathcal{B}(\\eta_c\\to K^0_SK^\\pm\\pi^\\mp) < 1.6\\times10^{-5}$ and $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c(2S))\\times \\mathcal{B}(\\eta_c(2S)\\to K^0_SK^\\pm\\pi^\\mp) < 5.6\\times10^{-6}$. Combining our result with world-average values of $\\mathcal{B}(\\eta_c(\\eta_c(2S))\\to K^0_SK^\\pm\\pi^\\mp)$, we find the branching fractions $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c) < 6.8\\times10^{-4}$ and $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c(2S)) < 2.0\\times10^{-3}$ at a 90% confidence level.

  4. On the Covariance of the Charge Form Factor in the Transition Radiation Energy Spectrum of a Beam at Normal Incidence onto a Metallic Screen

    CERN Document Server

    Orlandi, Gian Luca

    2012-01-01

    A charge-density-like covariance is expected to characterize the transition radiation energy spectrum of a N electron bunch as far as the charge form factor is intended to account for bunch-density effects in the radiation emission. The beam charge passing from a single electron to a high density electron bunch, the covariance of the transition radiation energy is expected to evolve from a charge-point-like to a charge-density-like one. Besides covariance, the radiation energy spectrum is expected to conform to the temporal causality principle: the N single electron amplitudes composing the radiation field are expected to propagate from the metallic screen with relative emission phases causally correlated with the temporal sequence of the N particle collisions onto the metallic screen. In the present paper, the case of a N electron bunch hitting at a normal angle of incidence a flat metallic surface with arbitrary size and shape will be considered. For such an experimental situation, the distribution function...

  5. The search for a standard model Higgs at the LHC and electron identification using transition radiation in the ATLAS tracker

    Energy Technology Data Exchange (ETDEWEB)

    Egede, U.

    1998-01-01

    The large Hadron Collider (LHC) will be ready for proton-proton collisions in the year 2005 and the ATLAS detector will be one of the two experiments at the LHC which will explore a new and higher energy range for particle physics. In this thesis, an analysis of the power of the ATLAS detector to detect a Standard Model Higgs boson has been performed. It is shown that it will be possible to discover a Higgs particle across the complete mass range from the lower limit defined by the reach of the LEP2 collider experiments to the upper theoretical limit around 1 TeV. The role of the inner tracking detector of ATLAS for the detection of conversions and the identification of the primary vertex in the detection of a Higgs particle in the Higgs to two photon decay channel is demonstrated with a detailed detector simulation. The identification of a 1 TeV Higgs particle requires a good understanding of both the signal and the backgrounds. The related uncertainties are covered in detail and it is shown that the Higgs can be identified in the H{yields}WW{yields}lvjj, H{yields}ZZ{yields}llvv and H{yields}ZZ{yields}lljj decay channels. The Transition Radiation Tracker (TRT) is a combined tracking and electron identification device which will be a part of the inner tracking detector of ATLAS. For a prototype of the TRT the electron identification performance is analysed and it is shown that the full scale TRT together with the calorimeters will provide the electron identification power required for a clean electron and photon signal at the LHC. For the prototype a rejection factor of 100 against pions was achieved with an electron efficiency of 90%. the importance of the TRT for a clear detection of a Higgs particle is demonstrated. 82 refs, figs, tabs.

  6. Statistical nanoscale study of localised radiative transitions in GaN/AlGaN quantum wells and AlGaN epitaxial layers

    Science.gov (United States)

    Rigutti, L.; Mancini, L.; Lefebvre, W.; Houard, J.; Hernàndez-Maldonado, D.; Di Russo, E.; Giraud, E.; Butté, R.; Carlin, J.-F.; Grandjean, N.; Blavette, D.; Vurpillot, F.

    2016-09-01

    Compositional disorder has important consequences on the optical properties of III-nitride ternary alloys. In AlGaN epilayers and AlGaN-based quantum heterostructures, the potential fluctuations induced by such disorder lead to the localisation of carriers at low temperature, which affects their transition energies. Using the correlations between micro-photoluminescence, scanning transmission electron microscopy and atom probe tomography we have analysed the optical behaviour of Al0.25Ga0.75N epilayers and that of GaN/AlGaN quantum wells, and reconstructed in three dimensions the distribution of chemical species with sub-nanometre spatial resolution. These composition maps served as the basis for the effective mass calculation of electrons and holes involved in radiative transitions. Good statistical predictions were subsequently obtained for the above-mentioned transition and localisation energies by establishing a link with their microstructural properties.

  7. Radiological Protection in Transition. Proceedings of the 14. Regular Meeting of the Nordic Society for Radiation Protection, NSFS

    Energy Technology Data Exchange (ETDEWEB)

    Valentin, J.; Cederlund, T.; Drake, P.; Finne, I.E.; Glansholm, A.; Jaworska, A.; Paile, W.; Rahola, T. (eds.)

    2005-09-01

    These proceedings comprise the papers and posters presented at the 14th Regular Meeting of the Nordic Society for Radiation Protection, the theme of which was 'Radiological protection in transformation'. There were sessions on international developments and stakeholder involvement, on education, training, and measurements, on emergencies, on nuclear installations, on non-ionising radiation, on medical radiation, on industrial uses of radiation, on radiobiology, on natural sources of radiation, on non-nuclear waste, on NKS (Nordic Nuclear Safety Research), on radioecology and artificial radionuclides in the environment, and on regulatory and international activities. In addition to invited lectures and proffered papers, there were educational primer lessons in the mornings and several roundtable discussions. In all, there were almost 100 contributions from participants representing at least 10 different countries. The range of different topics covered, the scientific quality of the contributions, and the interest shown in this meeting reflect the high standing of radiological protection in the Nordic countries.

  8. Wavelengths, oscillator strengths and radiative transition rates for K{alpha} lines in titanium x-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hu Feng; Wang Chuangke; Zhao Xuefeng [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Yang Jiamin; Jiang Gang, E-mail: yjm70018@my-public.sc.cninfo.net [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610064 (China)

    2011-06-15

    The oscillator strengths, line strengths and wavelengths are presented for all 1s-2p transitions in titanium ions. X-ray emission from titanium is extensively used, for example for diagnosis, in fusion experiments. The K{alpha} 1s-2p transitions are limited to transitions from helium-like to fluorine-like ion as the 2p subshell is filled beyond fluorine. While there are two 1s-2p transitions (1s{sup 2}S{sub 1/2}-2p{sup 2}P{sub 1/2} and 1s{sup 2}S{sub 1/2}-2p{sup 2}P{sub 3/2}) for hydrogen-like titanium, Ti{sup 20+}, the number varies depending on the number of electrons in the 2p subshell before and after the transition. For example, there are 35 1s-2p transitions giving the same number of K{alpha} lines for carbon-like titanium, Ti{sup 16+}. The present results are obtained from configuration interaction atomic structure calculations using the code GRASPVU, which includes relativistic effects in the Dirac-Fock approximation. The results have been benchmarked for a few ionic states. A comparison of our results with the very few transitions in the literature as well as those from other codes shows reasonable accuracy of the present results.

  9. Calculation of spectroscopic constants and radiative parameters for the A 1Σ+- X 1Σ+ electronic transitions of the CsLi and CsRb molecules

    Science.gov (United States)

    Smirnov, A. D.

    2016-12-01

    Vibrational, rotational, and centrifugal spectroscopic constants; radiative parameters (the Einstein coefficients for spontaneous emission, the oscillator strengths for absorption, and the Franck-Condon factors), the r v' v″-centroids; the wavenumbers of rotational lines of rovibronic transitions in the systems of bands A 1Σ+- X 1Σ+ of CsLi (0 ≤ v' ≤ 25, 0 ≤ v″ ≤ 51, j = 0, 30, 50, 70, 100) and CsRb (0 ≤ v' ≤ 30, 0 ≤ v″ ≤ 64, j = 0, 50, 100) molecules; and the radiative lifetimes for excited electronic states are calculated. The calculations are carried out on the basis of semiempirical potential curves constructed in this work. The calculated spectroscopic constants are compared with the experimental data. The lifetimes have been obtained for the first time.

  10. Effects of QCD phase transition on gravitational radiation from two-dimensional collapse and bounce of massive stars

    CERN Document Server

    Yasutake, N; Hashimoto, M; Yamada, S; Yasutake, Nobutoshi; Kotake, Kei; Hashimoto, Masa-aki; Yamada, Shoichi

    2007-01-01

    We perform two-dimensional, magnetohydrodynamical core-collapse simulations of massive stars accompanying the QCD phase transition. We study how the phase transition affects the gravitational waveforms near the epoch of core-bounce. As for initial models, we change the strength of rotation and magnetic fields. Particularly, the degree of differential rotation in the iron core (Fe-core) is changed parametrically. As for the microphysics, we adopt a phenomenological equation of state above the nuclear density, including two parameters to change the hardness before the transition. We assume the first order phase transition, where the conversion of bulk nuclear matter to a chirally symmetric quark-gluon phase is described by the MIT bag model. Based on these computations, we find that the phase transition can make the maximum amplitudes larger up to $\\sim$ 10 percents than the ones without the phase transition. On the other hand, the maximum amplitudes become smaller up to $\\sim$ 10 percents owing to the phase tr...

  11. Commissioning and performance of the ATLAS Transition Radiation Tracker with first high energy pp and Pb-Pb collisions at LHC

    CERN Document Server

    Schaepe, S; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider at CERN. It consists of close to 300000 thin-wall drift tubes (straws) providing on average 30 two-dimensional space points with 0.12-0.15 mm resolution for charged particle tracks with |η| 0.5 GeV. Along with continuous tracking, it provides particle identification capability through the detection of transition radiation X-ray photons generated by high velocity particles in the many polymer fibers or films that fill the spaces between the straws. Custom-built analog and digital electronics is optimized to operate as luminosity increases to the LHC design. In this talk, a review of the commissioning and first operational experience of the TRT detector will be presented. Emphasis will be given to performance studies based on the reconstruction and analysis of LHC collisions. A comparison of the TRT response to two very different center of mass energy collisions (900 ...

  12. Commissioning and performance of the ATLAS Transition Radiation Tracker with first high energy pp and Pb-Pb collisions at LHC

    CERN Document Server

    Schaepe, S; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider at CERN. It consists of close to 300000 thin-wall drift tubes (straws) providing on average 30 two-dimensional space points with 0.12-0.15 mm resolution for charged particle tracks with |η| 0.5 GeV. Along with continuous tracking, it provides particle identification capability through the detection of transition radiation X-ray photons generated by high velocity particles in the many polymer fibers or films that fill the spaces between the straws. Custom-built analog and digital electronics is optimized to operate as luminosity increases to the LHC design. In this article, a review of the commissioning and first operational experience of the TRT detector will be presented. Emphasis will be given to performance studies based on the reconstruction and analysis of LHC collisions. The first studies of the TRT detector response to the extremely high track density conditi...

  13. Commissioning and performance of the ATLAS Transition Radiation Tracker with first high energy pp and Pb-Pb collisions at LHC

    CERN Document Server

    Stahlman, JM; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider at CERN. It consists of close to 300000 thin-wall drift tubes (straws) providing on average 30 two-dimensional space points with 0.12-0.15 mm resolution for charged particle tracks with |η| < 2 and pT > 0.5 GeV. Along with continuous tracking, it provides particle identification capability through the detection of transition radiation X-ray photons generated by high velocity particles in the many polymer fibers or films that fill the spaces between the straws. Custom-built analog and digital electronics is optimized to operate as luminosity increases to the LHC design. In this talk, a review of the commissioning and first operational experience of the TRT detector will be presented. Emphasis will be given to performance studies based on the reconstruction and analysis of LHC collisions. A comparison of the TRT response to two very different center of ma...

  14. SU-E-T-62: A Preliminary Experience of Using EPID Transit Dosimetry for Monitoring Daily Dose Variations in Radiation Treatment Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yao, R; Chisela, W [Columbus Regional Healthcare, Columbus, GA (United States)

    2015-06-15

    Purpose: To investigate the use of EPID transit dosimetry for monitoring daily dose variations in radiation treatment delivery. Methods: A patient with head and neck cancer treated using nine field IMRT beams was used in this study. The prescription was 45 Gy in 25 fractions. A KV CBCT was acquired before each treatment on a Varian NTX linear accelerator. Integrated images using MV EPID were acquired for each treatment beam. Planning CT images, treatment plan, and daily integrated images were imported into a commercial QA software Dosimetry Check (v4r4 Math Resolutions, LLC, Columbia, MD) to calculate 3D dose of the day assuming 25 fractions treatment. Planning CT images were deformed and registered to each daily CBCT using Varian SmartAdapt (v11.MR2). ROIs were then propagated from planning CT to daily CBCT. The correlation between maximum, average dose of ROIs and ROI volume, center of mass shift, Dice Similarity Coefficient (DSC) were investigated. Results: Not all parameters investigated showed strong correlations. For PTV and CTV, the average dose has inverse correlation with their volume change (correlation coefficient −0.52, −0.50, respectively) and DSC (−0.59, −0.59, respectively). The average dose of right parotid has correlation with its volume change (0.56). The maximum dose of spinal cord has correlation with the center of mass superior-inferior shift (0.52) and inverse correlation with the center of mass anterior-posterior shift (−0.73). Conclusion: Transit dosimetry using EPID images collected during treatment delivery offers great potential to monitor daily dose variations due to patient anatomy change, motion, and setup errors in radiation treatment delivery. It can provide a patient-specific QA tool valuable for adaptive radiation therapy. Further work is needed to validate the technique.

  15. High-resolution structural studies of ultra-thin magnetic, transition metal overlayers and two-dimensional transition metal oxides using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kellar, S.A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley National Lab., CA (United States). Advanced Light Source Div.

    1997-05-01

    This thesis report the surface-structure determination of three, ultra-thin magnetic transition-metal films, Fe/Au(100), Mn/Ni(100), and Mn/Cu(100) using Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) and photoelectron holography. These structural studies are the first to use non-s initial states in the ARPEFS procedure. This thesis also reports an ARPEFS surface-structure determination of a two-dimensional transition-metal oxide, [(1 x 1)O/W(110)] x 12. The authors have analyzed the ARPFES signal from the Au 4f{sub 7/5} core level of the Au(1 ML)/Fe(15 ML)/Au(100) system. The analysis shows that the Fe grows layer by layer with one monolayer of gold, acting as a surfactant, remaining on top of the growing Fe layers. These surface gold atoms sit in the four-fold hollow site, 1.67 {+-} 0.02 A above the iron surface. The grown Fe layer is very much like the bulk, bcc iron, with an interlayer spacing of 1.43 {+-} 0.03 A. Analysis of the Mn 3p ARPEFS signals from c(2 x 2)Mn/Ni(100) and c(2 x 2)Mn/Cu(100) shows that the Mn forms highly corrugated surface alloys. The corrugation of the Mn/Ni(100) and Mn/Cu(100) systems are 0.24 {+-} 0.02 A and 0.30 {+-} 0.04 A respectively. In both cases the Mn is sticking above the plane of the surface substrate atoms. For the Mn/Ni(100) system the first layer Ni is contracted 4% from the bulk value. The Mn/Cu(100) system shows bulk spacing for the substrate Cu. Photoelectron holography shows that the Mn/Ni interface is very abrupt with very little Mn leaking into the second layer, while the Mn/Cu(100) case has a significant amount of Mn leaking into the second layer. A new, five-element electrostatic electron lens was developed for hemispherical electron-energy analyzers. This lens system can be operated at constant transverse or constants angular magnification, and has been optimized for use with the very small photon-spot sizes. Improvements to the hemispherical electron-energy analyzer are also discussed.

  16. Three-dimensional radiative transfer simulations of the scattering polarization of the hydrogen Ly$\\alpha$ line in a MHD model of the chromosphere-corona transition region

    CERN Document Server

    Stepan, Jiri; Leenaarts, Jorrit; Carlsson, Mats

    2015-01-01

    Probing the magnetism of the upper solar chromosphere requires measuring and modeling the scattering polarization produced by anisotropic radiation pumping in UV spectral lines. Here we apply PORTA (a novel radiative transfer code) to investigate the hydrogen Ly$\\alpha$ line in a 3D model of the solar atmosphere resulting from a state of the art MHD simulation. At full spatial resolution the linear polarization signals are very significant all over the solar disk, with a large fraction of the field of view showing line-center amplitudes well above the 1% level. Via the Hanle effect the line-center polarization signals are sensitive to the magnetic field of the model's transition region, even when its mean field strength is only 15 G. The breaking of the axial symmetry of the radiation field produces significant forward-scattering polarization in Ly$\\alpha$, without the need of an inclined magnetic field. Interestingly, the Hanle effect tends to decrease such forward-scattering polarization signals in most of ...

  17. Dominance of Radiated Aerodynamic Noise on Boundary-Layer Transition in Supersonic-Hypersonic Wind Tunnels. Theory and Application

    Science.gov (United States)

    1978-03-01

    since the radiated pressure f luc tuat ions t ravel along inc l ine rays s im i la r to, but somewhat steeper than, Mach waves [see Refer- ence...Supersonic Wind Tunnels," AEDC-TN-61-153 (AD270596), January 1962. 311 A E D C-TR -77-107 157. Tucker, Maurice . "Approximate Calculation of

  18. Numerical simulations of contrail-to-cirrus transition – Part 2: Impact of initial ice crystal number, radiation, stratification, secondary nucleation and layer depth

    Directory of Open Access Journals (Sweden)

    S. Unterstrasser

    2010-02-01

    Full Text Available Simulations of contrail-to-cirrus transition were performed with an LES model. In Part 1 the impact of relative humidity, temperature and vertical wind shear was explored in a detailed parametric study. Here, we study atmospheric parameters like stratification and depth of the supersaturated layer and processes which may affect the contrail evolution. We consider contrails in various radiation scenarios herein defined by the season, time of day and the presence of lower-level cloudiness which controls the radiance incident on the contrail layer. Under suitable conditions, controlled by the radiation scenario and stratification, radiative heating lifts the contrail-cirrus and prolongs its lifetime. The potential of contrail-driven secondary nucleation is investigated. We consider homogeneous nucleation and heterogeneous nucleation of preactivated soot cores released from sublimated contrail ice crystals. In our model the contrail dynamics triggered by radiative heating does not suffice to force homogeneous freezing of ambient liquid aerosol particles. Furthermore, our model results suggest that heterogeneous nucleation of preactivated soot cores is unimportant. Contrail evolution is not controlled by the depth of the supersaturated layer as long as it exceeds roughly 500 m. Deep fallstreaks however need thicker layers. A variation of the initial ice crystal number is effective during the whole evolution of a contrail. A cut of the soot particle emission by two orders of magnitude can reduce the contrail timescale by one hour and the optical thickness by a factor of 5. Hence future engines with lower soot particle emissions could potentially lead to a reduction of the climate impact of aviation.

  19. Near-field radiated wave field may help to understand the style of the supershear transition of dynamic ruptures

    Science.gov (United States)

    Bizzarri, Andrea; Liu, Chao

    2016-12-01

    Supershear earthquakes are known to leave special signatures in the signals on the fault (fault slip velocity, dynamic traction evolution, energy flux, etc.) and in the ground motions. Moreover, two different styles of supershear transition have been identified; in the direct transition (DT) mechanism the rupture speed continuously increases from the sub-Rayleigh to the terminal speed of P waves, while in the mother-daughter (MD) mechanism a forbidden zone of rupture speed exists and a secondary pseudo-rupture is generated ahead of the primary rupture front. Here we found that the off-fault signals (wavefields) generated by these two mechanisms are rather different, in that the MD case contains an enhanced trailing Rayleigh field, which has very low amplitudes (or it is even practically absent) in the DT case, and possess higher frequency content. Therefore, we show that it is possible to distinguish the style of the supershear transition from the records of real earthquakes. In particular, basing on the results of our numerical simulations, we can conclude that the Denali, Alaska, earthquake was basically controlled by a classical MD mechanism.

  20. New technique for a simultaneous estimation of the level density and radiative strength functions of dipole transitions at E sub e sub x<=B sub n -0.5 MeV

    CERN Document Server

    Khitrov, V A

    2001-01-01

    The new, model-independent method to estimate simultaneously the level densities excited in the (n,gamma) reaction and the radiative strength functions of dipole transitions is developed. The method can be applied for any nucleus and reaction followed by cascade gamma-emission. It is just necessary to measure the intensities of two-step gamma-cascades depopulating one or several high-excited states and determine the quanta ordering in the main portion of the observed cascades. The method provides a sufficiently narrow interval of most probable densities of levels with given J suppi and radiative strength functions of dipole transitions populating them.

  1. Process for Transition of Uranium Mill Tailings Radiation Control Act Title II Disposal Sites to the U.S. Department of Energy Office of Legacy Management for Long-Term Surveillance and Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-03-01

    This document presents guidance for implementing the process that the U.S. Department of Energy (DOE) Office of Legacy Management (LM) will use for assuming perpetual responsibility for a closed uranium mill tailings site. The transition process specifically addresses sites regulated under Title II of the Uranium Mill Tailings Radiation Control Act (UMTRCA) but is applicable in principle to the transition of sites under other regulatory structures, such as the Formerly Utilized Sites Remedial Action Program.

  2. Search for dimuon decays of a light scalar boson in radiative transitions Upsilon-->gammaA0.

    Science.gov (United States)

    Aubert, B; Karyotakis, Y; Lees, J P; Poireau, V; Prencipe, E; Prudent, X; Tisserand, V; Garra Tico, J; Grauges, E; Martinelli, M; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Battaglia, M; Brown, D N; Kerth, L T; Kolomensky, Yu G; Lynch, G; Osipenkov, I L; Petigura, E; Tackmann, K; Tanabe, T; Hawkes, C M; Soni, N; Watson, A T; Koch, H; Schroeder, T; Asgeirsson, D J; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Barrett, M; Khan, A; Randle-Conde, A; Blinov, V E; Bukin, A D; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Atmacan, H; Gary, J W; Liu, F; Long, O; Vitug, G M; Yasin, Z; Sharma, V; Campagnari, C; Hong, T M; Kovalskyi, D; Mazur, M A; Richman, J D; Beck, T W; Eisner, A M; Heusch, C A; Kroseberg, J; Lockman, W S; Martinez, A J; Schalk, T; Schumm, B A; Seiden, A; Wang, L; Winstrom, L O; Cheng, C H; Doll, D A; Echenard, B; Fang, F; Hitlin, D G; Narsky, I; Ongmongkolku, P; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Bloom, P C; Ford, W T; Gaz, A; Hirschauer, J F; Nagel, M; Nauenberg, U; Smith, J G; Wagner, S R; Ayad, R; Toki, W H; Wilson, R J; Feltresi, E; Hauke, A; Jasper, H; Karbach, T M; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Kobel, M J; Nogowski, R; Schubert, K R; Schwierz, R; Volk, A; Bernard, D; Latour, E; Verderi, M; Clark, P J; Playfer, S; Watson, J E; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Fioravanti, E; Franchini, P; Luppi, E; Munerato, M; Negrini, M; Petrella, A; Piemontese, L; Santoro, V; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Contri, R; Guido, E; Lo Vetere, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Tosi, S; Chaisanguanthum, K S; Morii, M; Adametz, A; Marks, J; Schenk, S; Uwer, U; Bernlochner, F U; Klose, V; Lacker, H M; Bard, D J; Dauncey, P D; Tibbetts, M; Behera, P K; Charles, M J; Mallik, U; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Arnaud, N; Béquilleux, J; D'Orazio, A; Davier, M; Derkach, D; Firmino da Costa, J; Grosdidier, G; Le Diberder, F; Lepeltier, V; Lutz, A M; Malaescu, B; Pruvot, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; Clarke, C K; Di Lodovico, F; Sacco, R; Sigamani, M; Cowan, G; Paramesvaran, S; Wren, A C; Brown, D N; Davis, C L; Denig, A G; Fritsch, M; Gradl, W; Hafner, A; Alwyn, K E; Bailey, D; Barlow, R J; Jackson, G; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Dallapiccola, C; Salvati, E; Cowan, R; Dujmic, D; Fisher, P H; Henderson, S W; Sciolla, G; Spitznagel, M; Yamamoto, R K; Zhao, M; Patel, P M; Robertson, S H; Schram, M; Biassoni, P; Lazzaro, A; Lombardo, V; Palombo, F; Stracka, S; Bauer, J M; Cremaldi, L; Godang, R; Kroeger, R; Sonnek, P; Summers, D J; Zhao, H W; Simard, M; Taras, P; Nicholson, H; De Nardo, G; Lista, L; Monorchio, D; Onorato, G; Sciacca, C; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; LoSecco, J M; Wang, W F; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Sekula, S J; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Castelli, G; Gagliardi, N; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; del Amo Sanchez, P; Ben-Haim, E; Bonneaud, G R; Briand, H; Chauveau, J; Hamon, O; Leruste, Ph; Marchiori, G; Ocariz, J; Perez, A; Prendki, J; Sitt, S; Gladney, L; Biasini, M; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Calderini, G; Carpinelli, M; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Lopes Pegna, D; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Anulli, F; Baracchini, E; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Franek, B; Olaiya, E O; Wilson, F F; Emery, S; Esteve, L; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yèche, Ch; Zito, M; Allen, M T; Aston, D; Bartoldus, R; Benitez, J F; Cenci, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Franco Sevilla, M; Gabareen, A M; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P

    2009-08-21

    We search for evidence of a light scalar boson in the radiative decays of the Upsilon(2S) and Upsilon(3S) resonances: Upsilon(2S,3S)-->gammaA0, A0-->mu+mu-. Such a particle appears in extensions of the standard model, where a light CP-odd Higgs boson naturally couples strongly to b quarks. We find no evidence for such processes in the mass range 0.212 mu+mu-)<0.9% at 90% confidence level.

  3. Development of the control system of the ALICE transition radiation detector and of a test environment for quality-assurance of its front-end electronics

    Energy Technology Data Exchange (ETDEWEB)

    Mercado Perez, Jorge

    2008-11-10

    Within this thesis, the detector control system (DCS) for the Transition Radiation Detector (TRD) of the ALICE experiment at the Large Hadron Collider has been developed. The TRD DCS is fully implemented as a detector oriented hierarchy of objects behaving as finite state machines. It controls and monitors over 65 thousand front-end electronics (FEE) units, a few hundred low voltage and one thousand high voltage channels, and other sub-systems such as cooling and gas. Commissioning of the TRD DCS took place during several runs with ALICE using cosmic events. Another part of this thesis describes the development of a test environment for large-scale production quality-assurance of over 4 thousand FEE read-out boards containing in total about 1.2 million read-out channels. The hardware and software components are described in detail. Additionally, a series of performance studies were carried out earlier including radiation tolerance tests of the TRAP chip which is the core component of the TRD FEE. (orig.)

  4. Search for Dimuon Decays of a Light Scalar Boson in Radiative Transitions Υ→γA0

    Science.gov (United States)

    Aubert, B.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Petigura, E.; Tackmann, K.; Tanabe, T.; Hawkes, C. M.; Soni, N.; Watson, A. T.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Fulsom, B. G.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Barrett, M.; Khan, A.; Randle-Conde, A.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Bondioli, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Lund, P.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Yasin, Z.; Sharma, V.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Mazur, M. A.; Richman, J. D.; Beck, T. W.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Wang, L.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Fang, F.; Hitlin, D. G.; Narsky, I.; Ongmongkolku, P.; Piatenko, T.; Porter, F. C.; Andreassen, R.; Mancinelli, G.; Meadows, B. T.; Mishra, K.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Hirschauer, J. F.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Wilson, R. J.; Feltresi, E.; Hauke, A.; Jasper, H.; Karbach, T. M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Kobel, M. J.; Nogowski, R.; Schubert, K. R.; Schwierz, R.; Volk, A.; Bernard, D.; Latour, E.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Chaisanguanthum, K. S.; Morii, M.; Adametz, A.; Marks, J.; Schenk, S.; Uwer, U.; Bernlochner, F. U.; Klose, V.; Lacker, H. M.; Bard, D. J.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Charles, M. J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Béquilleux, J.; D'Orazio, A.; Davier, M.; Derkach, D.; Firmino da Costa, J.; Grosdidier, G.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Malaescu, B.; Pruvot, S.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Burke, J. P.; Chavez, C. A.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Clarke, C. K.; di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; West, T. J.; Yi, J. I.; Anderson, J.; Chen, C.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Henderson, S. W.; Sciolla, G.; Spitznagel, M.; Yamamoto, R. K.; Zhao, M.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Bauer, J. M.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Zhao, H. W.; Simard, M.; Taras, P.; Nicholson, H.; de Nardo, G.; Lista, L.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; Losecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kagan, H.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Regensburger, J. J.; Sekula, S. J.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Lu, M.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Voci, C.; Del Amo Sanchez, P.; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Perez, A.; Prendki, J.; Sitt, S.; Gladney, L.; Biasini, M.; Manoni, E.; Angelini, C.; Batignani, G.; Bettarini, S.; Calderini, G.; Carpinelli, M.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Morganti, M.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.

    2009-08-01

    We search for evidence of a light scalar boson in the radiative decays of the Υ(2S) and Υ(3S) resonances: Υ(2S,3S)→γA0, A0→μ+μ-. Such a particle appears in extensions of the standard model, where a light CP-odd Higgs boson naturally couples strongly to b quarks. We find no evidence for such processes in the mass range 0.212≤mA0≤9.3GeV in the samples of 99×106 Υ(2S) and 122×106 Υ(3S) decays collected by the BABAR detector at the SLAC PEP-II B factory and set stringent upper limits on the effective coupling of the b quark to the A0. We also limit the dimuon branching fraction of the ηb meson: B(ηb→μ+μ-)<0.9% at 90% confidence level.

  5. The effect of temperature and pressure on optical absorption spectra of transition zone minerals - Implications for the radiative conductivity of the Earth's interior

    Science.gov (United States)

    Thomas, S.; Jacobsen, S. D.; Bina, C. R.; Goncharov, A. F.; Frost, D. J.; McCammon, C. A.

    2010-12-01

    Optical absorption spectra of high-pressure minerals can be used as indirect tools to calculate radiative conductivities of the Earth’s interior [e.g., 1]. Recent high-pressure studies imply that e.g. ringwoodite, γ-(Mg,Fe)2SiO4, does not become opaque in the near infrared and visible region, as previously assumed, but remains transparent to 21.5 GPa [2]. Therefore, it has been concluded that radiative heat transfer does not necessarily become blocked at high pressures of the mantle and ferromagnesian minerals actually might contribute to the heat flow in the Earth’s interior [2]. However, experimental results on temperature effects on radiative heat transfer are not available. We studied the effect of both, pressure and temperature, on the optical absorption of hydrous Fe-bearing ringwoodite, γ-(Mg,Fe)2SiO4, and hydrous Fe-bearing wadsleyite, β-(Mg,Fe)2SiO4, which are the main components of the Earth’s transition zone. Gem-quality single-crystals were synthesized at 18 GPa and 1400 °C in a 5000t multianvil apparatus. Crystals were analyzed by Mössbauer and Raman spectroscopy, electron microprobe analysis and single-crystal X-ray diffraction. For optical absorption measurements in the IR - VIS - UV spectral range (400 - 50000 cm-1) 50 µm sized single-crystals of ringwoodite and wadsleyite were double polished to thicknesses of 13 µm and 18 µm, respectively, and loaded in resistively heated diamond-anvil cells with argon as pressure medium. After taking measurements at high pressure and room temperature, ringwoodite was studied at 26 GPa up to 650 °C and wadsleyite spectra were recorded at 16 GPa up to 450 °C. At ambient pressure the absorption spectrum of ringwoodite reveals a crystal field band (Fe2+) at 12075 cm-1, an intervalence charge transfer band (Fe2+ to Fe3+) at 16491 cm-1, and an absorption edge due to ligand-metal charge transfer close to 30000 cm-1. The wadsleyite spectrum is characterized by a similar absorption edge in the VIS-UV range

  6. Search for Dimuon Decays of a Light Scalar in Radiative Transitions Y(3S) -> gamma A0

    CERN Document Server

    Aubert, B

    2009-01-01

    The fundamental nature of mass is one of the greatest mysteries in physics. The Higgs mechanism is a theoretically appealing way to account for the different masses of elementary particles and implies the existence of a new, yet unseen particle, the Higgs boson. We search for evidence of a light scalar (e.g. a Higgs boson) in the radiative decays of the narrow Y(3S) resonance: Y(3S)->gamma A0, A0->mu+mu-. Such an object appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in a sample of 122*10^6 Y(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction product B(Y(3S)-> gamma A0)*B(A0->mu+mu-) at (0.25-5.2)*10^{-6} in the mass range 0.212mu+mu-)<0.8% at 90% C.L. The results are preliminary.

  7. Search for Dimuon Decays of a Light Scalar in Radiative Transitions Y(3S) -> gamma A0

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B

    2009-06-02

    The fundamental nature of mass is one of the greatest mysteries in physics. The Higgs mechanism is a theoretically appealing way to account for the different masses of elementary particles and implies the existence of a new, yet unseen particle, the Higgs boson. We search for evidence of a light scalar (e.g. a Higgs boson) in the radiative decays of the narrow {Upsilon}(3S) resonance: {Upsilon}(3S) {yields} {gamma}A{sup 0}, A{sup 0} {yields} {mu}{sup +}{mu}{sup -}. Such an object appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in a sample of 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction product {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} {mu}{sup +}{mu}{sup -}) at (0.25 - 5.2) x 10{sup -6} in the mass range 0.212 {<=} m{sub A{sup 0}} {<=} 9.3 GeV. We also set a limit on the dimuon branching fraction of the {eta}{sub b} meson {Beta}({eta}{sub b} {yields} {mu}{sup +}{mu}{sup -}) < 0.8% at 90% C.L. The results are preliminary.

  8. Development, simulation and test of transition radiation detector prototypes for the compressed baryonic matter experiment at the facility for antiproton and ion research

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Cyrano S.H.

    2014-07-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at FAIR. The TRD sub-detector will contribute to the global particle identification and track reconstruction of charged particles. The technical design goal for the TRD is to identify 90% electrons with a maximum pion contamination of 1%. The TRD and Ring Image CHerenkov (RICH) detector should reach a common pion rejection of 10{sup 4}, in order to measure charmonium and low-mass vector mesons. The position resolution should be between 200 and 300 μm in the anode wire direction. The most demanding aspect of the CBM TRD design is the high interaction rate of up to 10{sup 7} Hz resulting in a charged particle rate of up to 100 kHz/cm{sup 2} in the central part of the detector planes at SIS300 conditions. It is crucial to find the optimal radiator detector combination with a minimum material budget to limit scattering and background due to conversions and at the same time reach a sufficient pion rejection and position resolution. In this thesis it is confirmed that a Multi-Wire Proportional Counter (MWPC) with a Xe/CO{sub 2} gas thickness of 12mm provides sufficient absorption probability for TR-photons in combination with self-supporting low density PE foam or micro-structured foil radiators. A continuous investigation aiming at an optimal wire and pad-plane geometry, as well as a minimization of the material budget between active gas and radiator has been presented in hard- and software. A minimum photon absorption cross-section of the entrance window was realized with a thermally stretched aluminized Kapton foil, glued to a G11 support grid support frame. This structure limits the mechanical deformation of the entire window to 1mm/mbar. All MWPC prototypes include two wire planes. A symmetric amplification region of 2 x (3, 3.5 or 4)mm is followed by a short drift region of 6, 5 or 4 mm. The drift region reduces the gain

  9. Semiphenomenological approximation of the sums of experimental radiative strength functions for dipole gamma transitions of energy E γ below the neutron binding energy B n for mass numbers in the range 40 ≤ A ≤ 200

    Science.gov (United States)

    Sukhovoj, A. M.; Furman, W. I.; Khitrov, V. A.

    2008-06-01

    The sums of radiative strength functions for primary dipole gamma transitions, k( E1) + k( M1), are approximated to a high precision by a superposition of two functional dependences in the energy range 0.5 125Te, 128I, 137,138,139Ba, 140La, 150Sm, 156,158Gd, 160Tb, 163,164,165Dy, 166Ho, 168Er, 170Tm, 174Yb, 176,177Lu, 181Hf, 182Ta, 183,184,185,187W, 188,190,191,193Os, 192Ir, 196Pt, 198Au, and 200Hg nuclei. It is shown that, in any nuclei, radiative strength functions are a dynamical quantity and that the values of k( E1) + k( M1) for specific energies of gamma transitions and specific nuclei are determined by the structure of decaying and excited levels, at least up to the neutron binding energy B n .

  10. Calibration of the ALICE transition radiation detector and a study of Z{sup 0} and heavy quark production in pp colissions at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Bailhache, Raphaelle

    2009-01-28

    The ALICE Experiment is one of the four experiments installed at the Large Hadron Collider (LHC). One of its detector-systems, the Transition Radiation Detector (TRD), is a gas detector designed for electron identification and charged particle tracking. The charged particle ionizes the gas along its path and electrons drift in an uniform field of 700 V/cm over 3 cm before being amplified. We implemented procedures to calibrate the drift velocity of the electrons, the time-offset of the signal, the amplification factor and the width of the Pad Response Function (PDF) characterizing the sharing of the deposited charge over adjacent pads. Physics events (pp and PbPb collisions) will be used. The performances of the algorithms were tested on simulated pp collisions at {radical}(s)=14 TeV and on first real data taken with cosmic-rays in the ALICE setup. The calibration software was installed on the Data Acquisition System at CERN and executed continuously during the cosmic-ray data taking in 2008, providing a first determination of the calibration constants. This thesis presents also a study on the capability of the ALICE central barrel to detect the Z{sup 0} boson through the decay Z{sup 0}{yields}e{sup +}e{sup -} in pp collisions at 14 TeV. We demonstrated that the Z{sup 0}{yields}e{sup +}e{sup -} is characterized by a very clean signal in the dielectron reconstructed invariant mass spectrum. At such high transverse momentum (about 45 GeV/c), the electrons from Z{sup 0} are identified with the Transition Radiation Detector. The remaining background from misidentified pions and electrons from heavy-flavored decays are rejected by the requirement of two isolated reconstructed tracks. The main challenge comes from the very small production rate. Therefore we estimated the efficiency of a trigger based on a low p{sub T} cut and electron identification with the TRD and showed that about 100 Z{sup 0}{yields}e{sup +}e{sup -} can be reconstructed per year employing such a

  11. Excitation system of low-impedance foilless transition-radiation oscillator%低阻无箔渡越辐射振荡器励磁系统

    Institute of Scientific and Technical Information of China (English)

    曹亦兵; 贺军涛; 张建德; 令钧溥

    2012-01-01

    为开展L波段低阻无箔渡越辐射高功率微波发生器的单次实验,设计了一种满足需要的电容器储能脉冲磁场系统.系统储能电容5.4 mF,设计的螺线管线圈长45 cm,其理论电感和电阻值分别为42mH和0.66Ω.基于该设计,绕制了磁场线圈并搭建了实验平台,线圈实际电感和电阻值分别为40 mH和0.61 Ω.目击靶实验进一步证实了励磁系统产生的导引磁场能够较好地约束电子束.%The-guiding magnetic field system is designed to conduct the experimental investigation of the L-band low-impedance tailless transit-radiation oscillator. The total capacitance of the system is 5. 4 mF. The length of the designed solenoid is 45 cm, and its theoretical inductance and impedance are 42 mH and 0. 66 Ω respectively. Based on the design, the coil is fabricated and the corresponding platform for the experiment is established. The real inductance and impedance are 40 mH and 0. 61 Ω respectively. The target experiment testifies that the intense relativistic electron beam can be well guided by the designed magnetic field system.

  12. Comment on AMS02 results support the secondary origin of cosmic ray positrons

    CERN Document Server

    Dado, Shlomo

    2015-01-01

    Recently Blum, Katz and Waxman have claimed that the flux of high energy cosmic ray (CR) positrons near Earth that has been measured with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station can be produced in the collisions of Galactic CR protons and nuclei with the ambient matter in the Galactic interstellar medium (ISM). Their claim was based on an alleged "robust upper limit to the positron flux" which neglected the energy loss of e+'s in the ISM. Inclusion of this energy loss, however, yields a much smaller upper limit, which excludes secondary production in the ISM by the Galactic cosmic rays as the main origin of the CR e^+ flux above 10 GeV.

  13. Development, simulation and test of transition radiation detector prototypes for the compressed baryonic matter experiment at the facility for antiproton and ion research

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Cyrano S.H.

    2014-07-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at FAIR. The TRD sub-detector will contribute to the global particle identification and track reconstruction of charged particles. The technical design goal for the TRD is to identify 90% electrons with a maximum pion contamination of 1%. The TRD and Ring Image CHerenkov (RICH) detector should reach a common pion rejection of 10{sup 4}, in order to measure charmonium and low-mass vector mesons. The position resolution should be between 200 and 300 μm in the anode wire direction. The most demanding aspect of the CBM TRD design is the high interaction rate of up to 10{sup 7} Hz resulting in a charged particle rate of up to 100 kHz/cm{sup 2} in the central part of the detector planes at SIS300 conditions. It is crucial to find the optimal radiator detector combination with a minimum material budget to limit scattering and background due to conversions and at the same time reach a sufficient pion rejection and position resolution. In this thesis it is confirmed that a Multi-Wire Proportional Counter (MWPC) with a Xe/CO{sub 2} gas thickness of 12mm provides sufficient absorption probability for TR-photons in combination with self-supporting low density PE foam or micro-structured foil radiators. A continuous investigation aiming at an optimal wire and pad-plane geometry, as well as a minimization of the material budget between active gas and radiator has been presented in hard- and software. A minimum photon absorption cross-section of the entrance window was realized with a thermally stretched aluminized Kapton foil, glued to a G11 support grid support frame. This structure limits the mechanical deformation of the entire window to 1mm/mbar. All MWPC prototypes include two wire planes. A symmetric amplification region of 2 x (3, 3.5 or 4)mm is followed by a short drift region of 6, 5 or 4 mm. The drift region reduces the gain

  14. Optical transitions in semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Rupasov, Valery I. [ALTAIR Center LLC, Shrewsbury, MA 01545 (United States) and Landau Institute for Theoretical Physics, Moscow (Russian Federation)]. E-mail: rupasov@townisp.com

    2007-03-19

    Employing the Maxwell equations and conventional boundary conditions for the radiation field on the nanostructure interfaces, we compute the radiative spontaneous decay rate of optical transitions in spherical semiconductor nanocrystals, core-shell nanocrystals and nanostructures comprising more than one shell. We also show that the coupling between optical transitions localized in the shell of core-shell nanocrystals and radiation field is determined by both conventional electro-multipole momenta and electro-multipole 'inverse' momenta. The latter are proportional to the core radius even for interband transitions that should result in very strong optical transitions.

  15. Effects of thermal radiation heat transfer on flame acceleration and transition to detonation in dust cloud flames: Origins of dust explosion

    CERN Document Server

    Ivanov, Michael A Liberman M F

    2015-01-01

    We examines regimes of the hydrogen flames propagation and ignition of mixtures heated by the radiation emitted from the flame. The gaseous phase is assumed to be transparent for radiation, while the suspended particles of the dust cloud ahead of the flame absorb and reemit the radiation. The radiant heat absorbed by the particles is then lost by conduction to the surrounding unreacted gaseous phase so that the gas phase temperature lags that of the particles. The direct numerical simulations solve the full system of two phase gas dynamic time-dependent equations with a detailed chemical kinetics for a plane flames propagating through a dust cloud. Depending on the spatial distribution of the dispersed particles and on the value of radiation absorption length the consequence of the radiative preheating of the unreacted mixture can be either the increase of the flame velocity for uniformly dispersed particles or ignition deflagration or detonation ahead of the flame via the Zel'dovich gradient mechanism in the...

  16. Measurement of the radiative lifetime of the 2s(2)2p(4) (1)S(0) metastable level of neon; a study of forbidden transitions of astrophysical interest

    Science.gov (United States)

    Daw, Adrian Nigel

    The radiative lifetime of the 2s22 p4 1S0 metastable level of Ne2+ (Ne III) has been measured to be 223 +/- 11 ms at the 90% confidence level by observing the photons emitted at 1815 Å (181.5 nm) by a decaying population of 1 S0 Ne2+ ions stored in a radio frequency ion trap. This thesis describes the first use of a method to account for any ions lost from the trap and determine the radiative lifetime. Metastable ions were produced by electron bombardment of Ne gas, and rate coefficients for Ne2+ + Ne collisions were also determined. The lifetime measurement is in good agreement with recent calculated values, and has a lower uncertainty than the calculated values. This is the first lifetime measurement for an excited term of a ground configuration ion in the second row of the periodic table. The transition probabilities (A-values) for the forbidden transitions in the ground configurations of these ions are required for astrophysical spectral line intensity ratio diagnostics. Using calculated branching ratios, we estimate that, at the 90% confidence level, A(3P1 - 1S0) = 1.94 +/- 0.17 s-1 for the forbidden line of Ne III at 1815 Å, and A(1D2 - 1S0) = 2.55 +/- 0.19 s-1 for the forbidden line of Ne III at 3344 Å.

  17. Approximation of Sums of Experimental Radiative Strength Functions of Dipole Gamma-Transitions in the Region $E_\\gamma \\approx B_n$ for the Atomic Masses $40 \\leq a \\leq 200$

    CERN Document Server

    Sukhovoj, A M; Khitrov, V A

    2008-01-01

    The sums k(E1)+k(M1) of radiative strength functions of dipole primary gamma-transitions were approximated with high precision in the energy region of $0.5 < E_1 < B_n-0.5$ MeV for nuclei: 40K, 60Co, 71,74Ge, 80Br, 114Cd, 118Sn, 124,125Te, 128I, 137,138,139Ba, 140La, 150Sm, 156,158Gd, 160Tb, 163,164,165Dy, 166Ho, 168Er, 170Tm, 174Yb, 176,177Lu, 181Hf, 182Ta, 183,184,185,187W, 188,190,191,193Os, 192Ir, 196Pt, 198Au, 200Hg by sum of two independent functions. It has been shown that this parameter of gamma-decay are determined by the structure of the decaying and excited levels, at least, up to the neutron binding energy.

  18. Observation of a new $\\chi_b$ state in radiative transitions to $\\Upsilon$(1S) and $\\Upsilon$(2S) at ATLAS

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Aderholz, Michael; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Akiyama, Kunihiro; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Aliyev, Magsud; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral, Pedro; Amelung, Christoph; Ammosov, Vladimir; Amorim, Antonio; Amorós, Gabriel; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; Å sman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Astvatsatourov, Anatoli; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Ay, Cano; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barashkou, Andrei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Ben Ami, Sagi; Benary, Odette; Benchekroun, Driss; Benchouk, Chafik; Bendel, Markus; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertinelli, Francesco; Bertolucci, Federico; Besana, Maria Ilaria; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bitenc, Urban; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blazek, Tomas; Blocker, Craig; Blocki, Jacek; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boelaert, Nele; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bolnet, Nayanka Myriam; Bona, Marcella; Bondarenko, Valery; Bondioli, Mario; Boonekamp, Maarten; Booth, Chris; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borri, Marcello; Borroni, Sara; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Botterill, David; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozhko, Nikolay; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Braem, André; Branchini, Paolo; Brandenburg, George; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brelier, Bertrand; Bremer, Johan; Brenner, Richard; Bressler, Shikma; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brodbeck, Timothy; Brodet, Eyal; Broggi, Francesco; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, William; Brown, Gareth; Brown, Heather; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchanan, James; Buchanan, Norman; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Büscher, Volker; Bugge, Lars; Bulekov, Oleg; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butin, François; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Caloi, Rita; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarri, Paolo; Cambiaghi, Mario; Cameron, David; Caminada, Lea Michaela; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Capasso, Luciano; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Caramarcu, Costin; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carrillo Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Cataneo, Fernando; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cauz, Diego; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerqueira, Augusto Santiago; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Cevenini, Francesco; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Kevin; Chapleau, Bertrand; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Tingyang; Chen, Xin; Cheng, Shaochen; Cheplakov, Alexander; Chepurnov, Vladimir; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Illectra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciba, Krzysztof; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciobotaru, Matei Dan; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Clifft, Roger; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coe, Paul; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Colas, Jacques; Colijn, Auke-Pieter; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colon, German; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Michele; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conventi, Francesco; Cook, James; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Costin, Tudor; Côté, David; Coura Torres, Rodrigo; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Crescioli, Francesco; Cristinziani, Markus; Crosetti, Giovanni; Crupi, Roberto; Crépé-Renaudin, Sabine; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Curatolo, Maria; Curtis, Chris; Cuthbert, Cameron; Cwetanski, Peter; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Silva, Paulo Vitor; Da Via, Cinzia; Dabrowski, Wladyslaw; Dai, Tiesheng; Dallapiccola, Carlo; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dannheim, Dominik; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Eleanor; Davies, Merlin; Davison, Adam; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Dawson, John; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Castro Faria Salgado, Pedro; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De La Taille, Christophe; De la Torre, Hector; De Lotto, Barbara; de Mora, Lee; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dean, Simon; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Degenhardt, James; Dehchar, Mohamed; Del Papa, Carlo; Del Peso, Jose; Del Prete, Tarcisio; Delemontex, Thomas; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delruelle, Nicolas; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Deng, Jianrong; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Devetak, Erik; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diblen, Faruk; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dindar Yagci, Kamile; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; do Vale, Maria Aline Barros; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobinson, Robert; Dobos, Daniel; Dobson, Ellie; Dodd, Jeremy; Doglioni, Caterina; Doherty, Tom; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donadelli, Marisilvia; Donega, Mauro; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dosil, Mireia; Dotti, Andrea; Dova, Maria-Teresa; Dowell, John; Doxiadis, Alexander; Doyle, Tony; Drasal, Zbynek; Drees, Jürgen; Dressnandt, Nandor; Drevermann, Hans; Driouichi, Chafik; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Dudarev, Alexey; Dudziak, Fanny; Dührssen, Michael; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Düren, Michael; Ebenstein, William; Ebke, Johannes; Eckweiler, Sebastian; Edmonds, Keith; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Ehrich, Thies; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Eppig, Andrew; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrington, Sinead; Farthouat, Philippe; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Woiciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Fellmann, Denis; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Ferland, Jonathan; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrer, Maria Lorenza; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filippas, Anastasios; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fischer, Peter; Fisher, Matthew; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Fokitis, Manolis; Fonseca Martin, Teresa; Forbush, David Alan; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Foster, Joe; Fournier, Daniel; Foussat, Arnaud; Fowler, Andrew; Fowler, Ken; Fox, Harald; Francavilla, Paolo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Friedrich, Felix; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Gan, KK; Gao, Yongsheng; Gapienko, Vladimir; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; García, Carmen; García Navarro, José Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Garvey, John; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gayde, Jean-Christophe; Gazis, Evangelos; Ge, Peng; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilbert, Laura; Gilewsky, Valentin; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giunta, Michele; Giusti, Paolo; Gjelsten, Bø rge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Göpfert, Thomas; Goeringer, Christian; Gössling, Claus; Göttfert, Tobias; Goldfarb, Steven; Golling, Tobias; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; Gonidec, Allain; Gonzalez, Saul; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Gorokhov, Serguei; Goryachev, Vladimir; Gosdzik, Bjoern; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Groh, Manfred; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guarino, Victor; Guest, Daniel; Guicheney, Christophe; Guida, Angelo; Guindon, Stefan; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gupta, Ambreesh; Gusakov, Yury; Gushchin, Vladimir; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Haider, Stefan; Hajduk, Zbigniew; Hakobyan, Hrachya; Hall, David; Haller, Johannes; Hamacher, Klaus; Hamal, Petr; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Han, Hongguang; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jø rgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Karl; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Hatch, Mark; Hauff, Dieter; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawes, Brian; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hawkins, Donovan; Hayakawa, Takashi; Hayashi, Takayasu; Hayden, Daniel; Hayward, Helen; Haywood, Stephen; Hazen, Eric; He, Mao; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Henry-Couannier, Frédéric; Hensel, Carsten; Henß, Tobias; Hernandez, Carlos Medina; Hernández Jiménez, Yesenia; Herrberg, Ruth; Hershenhorn, Alon David; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Higón-Rodriguez, Emilio; Hill, Daniel; Hill, John; Hill, Norman; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Homma, Yasuhiro; Hong, Tae Min; Hooft van Huysduynen, Loek; Horazdovsky, Tomas; Horn, Claus; Horner, Stephan; Hostachy, Jean-Yves; Hou, Suen; Houlden, Michael; Hoummada, Abdeslam; Howarth, James; Howell, David; Hristova, Ivana; Hrivnac, Julius; Hruska, Ivan; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Huang, Guang Shun; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huettmann, Antje; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Hughes-Jones, Richard; Huhtinen, Mika; Hurst, Peter; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Ichimiya, Ryo; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuri; Iliadis, Dimitrios; Ilic, Nikolina; Imori, Masatoshi; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishikawa, Akimasa; Ishino, Masaya; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakubek, Jan; Jana, Dilip; Jankowski, Ernest; Jansen, Eric; Jansen, Hendrik; Jantsch, Andreas; Janus, Michel; Jarlskog, Göran; Jeanty, Laura; Jelen, Kazimierz; Jen-La Plante, Imai; Jenni, Peter; Jeremie, Andrea; Jež, Pavel; Jézéquel, Stéphane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Ge; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Lars; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tegid; Jones, Tim; Jonsson, Ove; Joram, Christian; Jorge, Pedro; Joseph, John; Jovicevic, Jelena; Jovin, Tatjana; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Juranek, Vojtech; Jussel, Patrick; Juste Rozas, Aurelio; Kabachenko, Vasily; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaiser, Steffen; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagounis, Michael; Karagoz, Muge; Karnevskiy, Mikhail; Karr, Kristo; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Kehoe, Robert; Keil, Markus; Kekelidze, George; Kennedy, John; Kenney, Christopher John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Kholodenko, Anatoli; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Nikolai; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Min Suk; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kirsch, Lawrence; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kittelmann, Thomas; Kiver, Andrey; Kladiva, Eduard; Klaiber-Lodewigs, Jonas; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Knecht, Neil; Kneringer, Emmerich; Knobloch, Juergen; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Köneke, Karsten; König, Adriaan; Koenig, Sebastian; Köpke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kokott, Thomas; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollefrath, Michael; Kolya, Scott; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kootz, Andreas; Koperny, Stefan; Korcyl, Krzysztof; Kordas, Kostantinos; Koreshev, Victor; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotamäki, Miikka Juhani; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, James; Kraus, Jana; Kreisel, Arik; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruth, Andre; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kundu, Nikhil; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lamanna, Massimo; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lane, Jenna; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larionov, Anatoly; Larner, Aimee; Lasseur, Christian; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Laycock, Paul; Lazarev, Alexandre; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Maner, Christophe; Le Menedeu, Eve; Lebel, Céline; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Leger, Annie; LeGeyt, Benjamin; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Leltchouk, Mikhail; Lemmer, Boris; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lessard, Jean-Raphael; Lesser, Jonas; Lester, Christopher; Leung Fook Cheong, Annabelle; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levitski, Mikhail; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Shu; Li, Xuefei; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Lifshitz, Ronen; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipinsky, Lukas; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Loken, James; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lo Sterzo, Francesco; Losty, Michael; Lou, Xinchou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Björn; Lundberg, Johan; Lundquist, Johan; Lungwitz, Matthias; Lutz, Gerhard; Lynn, David; Lys, Jeremy; Lytken, Else; Ma, Hong; Ma, Lian Liang; Macana Goia, Jorge Andres; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Mackeprang, Rasmus; Madaras, Ronald; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mättig, Peter; Mättig, Stefan; Magnoni, Luca; Magradze, Erekle; Mahalalel, Yair; Mahboubi, Kambiz; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Mangeard, Pierre-Simon; Manhaes de Andrade Filho, Luciano; Manjavidze, Ioseb; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Manz, Andreas; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marin, Alexandru; Marino, Christopher; Marroquim, Fernando; Marshall, Robin; Marshall, Zach; Martens, Kalen; Marti-Garcia, Salvador; Martin, Andrew; Martin, Brian; Martin, Brian; Martin, Franck Francois; Martin, Jean-Pierre; Martin, Philippe; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martin-Haugh, Stewart; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mathes, Markus; Matricon, Pierre; Matsumoto, Hiroshi; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maugain, Jean-Marie; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; May, Edward; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzanti, Marcello; Mazzoni, Enrico; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; McGlone, Helen; Mchedlidze, Gvantsa; McLaren, Robert Andrew; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehdiyev, Rashid; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Menot, Claude; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Meyer, W Thomas; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Miralles Verge, Lluis; Misiejuk, Andrzej; Mitrevski, Jovan; Mitrofanov, Gennady; Mitsou, Vasiliki A; Mitsui, Shingo; Miyagawa, Paul; Miyazaki, Kazuki; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mockett, Paul; Moed, Shulamit; Moeller, Victoria; Mönig, Klaus; Möser, Nicolas; Mohapatra, Soumya; Mohr, Wolfgang; Mohrdieck-Möck, Susanne; Moisseev, Artemy; Moles-Valls, Regina; Molina-Perez, Jorge; Monk, James; Monnier, Emmanuel; Montesano, Simone; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Morin, Jerome; Morley, Anthony Keith; Mornacchi, Giuseppe; Morozov, Sergey; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mudrinic, Mihajlo; Mueller, Felix; Mueller, James; Mueller, Klemens; Müller, Thomas; Mueller, Timo; Muenstermann, Daniel; Muir, Alex; Munwes, Yonathan; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nadal, Jordi; Nagai, Koichi; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Narayan, Rohin; Nash, Michael; Nation, Nigel; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nebot, Eduardo; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Silke; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen Thi Hong, Van; Nickerson, Richard; Nicolaidou, Rosy; Nicolas, Ludovic; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Niinikoski, Tapio; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolaev, Kirill; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishiyama, Tomonori; Nisius, Richard; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nordberg, Markus; Nordkvist, Bjoern; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; O'Brien, Brendan Joseph; O'Neale, Steve; O'Neil, Dugan; O'Shea, Val; Oakes, Louise Beth; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Ohshita, Hidetoshi; Okada, Shogo; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olcese, Marco; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Omachi, Chihiro; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Simon; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganis, Efstathios; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Paleari, Chiara; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panes, Boris; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Panuskova, Monika; Paolone, Vittorio; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Paredes Hernandez, Daniela; Park, Woochun; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Peng, Haiping; Pengo, Ruggero; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Cavalcanti, Tiago; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Persembe, Seda; Perus, Antoine; Peshekhonov, Vladimir; Peters, Krisztian; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Peter William; Piacquadio, Giacinto; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Ping, Jialun; Pinto, Belmiro; Pirotte, Olivier; Pizio, Caterina; Plamondon, Mathieu; Pleier, Marc-Andre; Pleskach, Anatoly; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Poghosyan, Tatevik; Pohl, Martin; Polci, Francesco; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomarede, Daniel Marc; Pomeroy, Daniel; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Posch, Christoph; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Pribyl, Lukas; Price, Darren; Price, Joe; Price, Lawrence; Price, Michael John; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przybycien, Mariusz; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Pueschel, Elisa; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qian, Zuxuan; Qin, Zhonghua; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radescu, Voica; Radics, Balint; Radloff, Peter; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Randrianarivony, Koloina; Ratoff, Peter; Rauscher, Felix; Rave, Tobias Christian; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reichold, Armin; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Renkel, Peter; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richards, Alexander; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robinson, Mary; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Rodriguez, Diego; Roe, Adam; Roe, Shaun; Røhne, Ole; Rojo, Victoria; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romanov, Victor; Romeo, Gaston; Romero Adam, Elena; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Anthony; Rose, Matthew; Rosenbaum, Gabriel; Rosenberg, Eli; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rosselet, Laurent; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexander; Rozen, Yoram; Ruan, Xifeng; Rubinskiy, Igor; Ruckert, Benjamin; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Christian; Rudolph, Gerald; Rühr, Frederik; Ruggieri, Federico; Ruiz-Martinez, Aranzazu; Rumiantsev, Viktor; Rumyantsev, Leonid; Runge, Kay; Rurikova, Zuzana; Rusakovich, Nikolai; Rust, Dave; Rutherfoord, John; Ruwiedel, Christoph; Ruzicka, Pavel; Ryabov, Yury; Ryadovikov, Vasily; Ryan, Patrick; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Rzaeva, Sevda; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Björn Hallvard; Sanchez, Arturo; Sanchez Martinez, Victoria; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sandvoss, Stephan; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Saraiva, João; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savu, Dan Octavian; Sawyer, Lee; Saxon, David; Says, Louis-Pierre; Sbarra, Carla; Sbrizzi, Antonio; Scallon, Olivia; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schäfer, Uli; Schaepe, Steffen; Schaetzel, Sebastian; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R~Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schlereth, James; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schmitz, Martin; Schöning, André; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schroeder, Christian; Schroer, Nicolai; Schuh, Silvia; Schuler, Georges; Schultens, Martin Johannes; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Jan; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Scott, Bill; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Segura, Ester; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Seuster, Rolf; Severini, Horst; Sevior, Martin; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaver, Leif; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shibata, Akira; Shichi, Hideharu; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shiyakova, Maria; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simmons, Brinick; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Skvorodnev, Nikolai; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Sloper, John erik; Smakhtin, Vladimir; Smart, Ben; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snuverink, Jochem; Snyder, Scott; Soares, Mara; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sosebee, Mark; Soualah, Rachik; Soukharev, Andrey; Spagnolo, Stefania; Spanò, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spila, Federico; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staude, Arnold; Stavina, Pavel; Stavropoulos, Georgios; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stevenson, Kyle; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Strube, Jan; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Styles, Nicholas Adam; Soh, Dart-yin; Su, Dong; Subramania, Halasya Siva; Succurro, Antonella; Sugaya, Yorihito; Sugimoto, Takuya; Suhr, Chad; Suita, Koichi; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Sushkov, Serge; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Suzuki, Yuta; Svatos, Michal; Sviridov, Yuri; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Szeless, Balazs; Sánchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanaka, Yoshito; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tappern, Geoffrey; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tatarkhanov, Mous; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teinturier, Marthe; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Testa, Marianna; Teuscher, Richard; Thadome, Jocelyn; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thioye, Moustapha; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tic, Tomáš; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tipton, Paul; Tique Aires Viegas, Florbela De Jes; Tisserant, Sylvain; Toczek, Barbara; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokunaga, Kaoru; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Guoliang; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torchiani, Ingo; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Trinh, Thi Nguyet; Tripiana, Martin; Trischuk, William; Trivedi, Arjun; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tudorache, Alexandra; Tudorache, Valentina; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Underwood, David; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valenta, Jan; Valente, Paolo; Valentinetti, Sara; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; van der Graaf, Harry; van der Kraaij, Erik; Van Der Leeuw, Robin; van der Poel, Egge; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; van Kesteren, Zdenko; van Vulpen, Ivo; Vanadia, Marco; Vandelli, Wainer; Vandoni, Giovanna; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Varela Rodriguez, Fernando; Vari, Riccardo; Varnes, Erich; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vegni, Guido; Veillet, Jean-Jacques; Vellidis, Constantine; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Virzi, Joseph; Vitells, Ofer; Viti, Michele; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vlasov, Nikolai; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Loeben, Joerg; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobiev, Alexander; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Voss, Thorsten Tobias; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wakabayashi, Jun; Walbersloh, Jorg; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Wang, Chiho; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Joshua C; Wang, Rui; Wang, Song-Ming; Warburton, Andreas; Ward, Patricia; Warsinsky, Markus; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Marc; Weber, Michele; Weber, Pavel; Weidberg, Anthony; Weigell, Philipp; Weingarten, Jens; Weiser, Christian; Wellenstein, Hermann; Wells, Phillippa; Wen, Mei; Wenaus, Torre; Wendler, Shanti; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Weydert, Carole; Whalen, Kathleen; Wheeler-Ellis, Sarah Jane; Whitaker, Scott; White, Andrew; White, Martin; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Wei-Cheng; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wraight, Kenneth; Wright, Catherine; Wright, Michael; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wunstorf, Renate; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xie, Song; Xie, Yigang; Xu, Chao; Xu, Da; Xu, Guofa; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamaoka, Jared; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Yi; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Yushu; Yasu, Yoshiji; Ybeles Smit, Gabriel Valentijn; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Riktura; Young, Charles; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaets, Vassilli; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zanello, Lucia; Zarzhitsky, Pavel; Zaytsev, Alexander; Zeitnitz, Christian; Zeller, Michael; Zeman, Martin; Zemla, Andrzej; Zendler, Carolin; Zenin, Oleg; Ženiš, Tibor; Zinonos, Zinonas; Zenz, Seth; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhan, Zhichao; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Tianchi; Zhao, Zhengguo; Zhemchugov, Alexey; Zheng, Shuchen; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zieminska, Daria; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Živković, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; Zolnierowski, Yves; Zsenei, Andras; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

    2012-01-01

    The $\\chi_b$(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at $\\sqrt{s}$ = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb$^{-1}$, these states are reconstructed through their radiative decays to $\\Upsilon$(1S,2S) with $\\Upsilon \\to \\mu^+ \\mu^-$. In addition to the mass peaks corresponding to the decay modes $\\chi_b(1P,2P) \\to \\Upsilon(1S)\\gamma$, a new structure centered at a mass of 10.539+/-0.004 (stat.)+/-0.008 (syst.) GeV is also observed, in both the $\\Upsilon(1S)\\gamma$ and $\\Upsilon(2S)\\gamma$ decay modes. This is interpreted as the $\\chi_b$(3P) system.

  19. Energy, fine structure, hyperfine structure, and radiative transition rates of the high-lying multi-excited states for B-like neon

    Science.gov (United States)

    Zhang, Chun Mei; Chen, Chao; Sun, Yan; Gou, Bing Cong; Shao, Bin

    2015-04-01

    The Rayleigh-Ritz variational method with multiconfiguration interaction wave functions is used to obtain the energies of high-lying multi-excited quartet states 1 s 22 s2 pnl and 1 s 22 p 2 nl 4Pe,o ( n ≥ 2) in B-like neon, including the mass polarization and relativistic corrections. The fine structure and hyperfine structure of the excited quartet states for this system are investigated. Configuration structures of the high-lying multi-excited series are further identified by relativistic corrections and fine structure splittings. The transition rates and wavelengths are also calculated. Calculated wavelengths include the quantum electrodynamic effects. The results are compared with other theoretical and experimental data in the literature.

  20. Radiation Protection

    Science.gov (United States)

    ... EPA United States Environmental Protection Agency Search Search Radiation Protection Share Facebook Twitter Google+ Pinterest Contact Us Radiation Protection Document Library View and download EPA radiation ...

  1. Radiation sickness

    Science.gov (United States)

    ... radiation. There are two basic types of radiation: ionizing and nonionizing. Nonionizing radiation comes in the form of light, radio waves, microwaves and radar. This kind of radiation usually ...

  2. Radiation enteritis

    Science.gov (United States)

    Radiation enteropathy; Radiation-induced small bowel injury; Post-radiation enteritis ... Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. The therapy ...

  3. Radiation Therapy

    Science.gov (United States)

    ... the area is stitched shut. Another treatment, called proton-beam radiation therapy , focuses the radiation on the ... after radiation treatment ends. Sore mouth and tooth decay. If you received radiation therapy to the head ...

  4. Metal-insulator transition in Si{sub 0.7}Ge{sub 0.3} disordered by fast neutron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhidkov, A.V. [AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Yadernykh Issledovanij

    1996-10-01

    Both n- and p-type heavily doped and irradiated Si{sub 0.7}Ge{sub 0.3} (N{sub D}, N{sub A}{approx}2.10{sup 26} cm{sup -3}) alloys behaviour was experimentally studied. After irradiation in vertical channels of Kiev WWR-M research reactor with neutron fluence of 10{sup 25} neutron/m{sup 2} (E>1 MeV), the material was determined to be an insulator because of observed Anderson-type metal-insulator transition. There were temperature dependency of specific resistance and Hall effect measurements, which allowed distinct detection of both the {epsilon}{sub 1}-conductivity provided by the thermal activation of carriers from Fermi level to percolation threshold and {epsilon}{sub 3}, where the hopping mechanism dominates. The unusual parameters of hopping process were observed at T<200 K, where this process dominates. The Fermi level value was estimated to be 55 meV relative to the mobility edge; estimated electron state localization radius value is <10 A. (orig.).

  5. Radiation dosimetry.

    OpenAIRE

    Cameron, J

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists.

  6. Spatial variability of ultraviolet-absorbing compounds in an aquatic liverwort and their usefulness as biomarkers of current and past UV radiation: A case study in the Atlantic–Mediterranean transition

    Energy Technology Data Exchange (ETDEWEB)

    Monforte, Laura; Tomás-Las-Heras, Rafael; Del-Castillo-Alonso, María-Ángeles; Martínez-Abaigar, Javier, E-mail: javier.martinez@unirioja.es; Núñez-Olivera, Encarnación

    2015-06-15

    The spatial variability of ultraviolet-absorbing compounds (UVACs) in the freshwater liverwort Jungermannia exsertifolia subsp. cordifolia was studied in mid-latitudes (the Atlantic–Mediterranean transition) across a wide lati-altitudinal gradient, with the aim of testing the usefulness of UVACs as biomarkers of current ambient levels of UV radiation. We analysed 17 samples from streams located in the main mountain ranges of the Iberian Peninsula, differentiating methanol-soluble (SUVACs, mainly located in the vacuoles) and methanol-insoluble (IUVACs, bound to cell walls) compounds, since they represent different manners to cope with UV radiation. In both fractions, the bulk level of UVACs and the concentrations of several individual compounds were measured. In addition, we measured F{sub v}/F{sub m}, DNA damage and sclerophylly index (SI) as possible additional UV biomarkers. UVACs showed a high variability, probably due not only to the gradients of macroenvironmental factors (UV radiation, PAR, and water temperature), but also to microenvironmental factors inherent to the dynamic nature of mountain streams. Two soluble coumarins were positively correlated with UV levels and could be used for ambient UV biomonitoring in the spatial scale. In contrast to the variability in UVACs, the relatively homogeneous values of F{sub v}/F{sub m} and the lack of any DNA damage made these variables useless for ambient UV biomonitoring, but suggested a strong acclimation capacity of this liverwort to changing environmental conditions (in particular, to UV levels). Finally, UVACs of fresh samples of the liverwort were compared to those of herbarium samples collected in the same lati-altitudinal gradient. SUVACs were significantly higher in fresh samples, whereas IUVACs generally showed the contrary. Thus, IUVACs were more stable than SUVACs and hence more adequate for retrospective UV biomonitoring. In conclusion, UVAC compartmentation should be taken into account for bryophyte

  7. Generation of sequences of daily radiation values using a library of Markov transition matrices. Application of weather station in tre University od Vigo; Generacion de secuencias de radiacion diaria utilizando librerias de matrices de Markov. Aplicacion a la estacion meteorologica de la Universidad de Vigo

    Energy Technology Data Exchange (ETDEWEB)

    Sieres, J. A.; Vazquez, M.; Fernandez-Seara, J.

    2004-07-01

    In this paper, the generation of sequences of daily radiation values using a library of Markov transition matrices is analysed. The paper describes the fundamentals of the method employed and how sequences of daily radiation can be generated using as input monthly averaged values of the clearness index. The method is applied to the location where the Solar Energy Lab Weather Station of the University of Vigo (longitude 8 degree 41' 18'' O, latitude 42 degree 10' 9'' N) is placed. Radiation sequences are generated for the years 2002 and 2003 and the results are compared with measured radiation values. Results of statistical tests show a bad performance of the generation method for the location studied. (Author)

  8. {mu}-Synchrotron radiation excited X-ray fluorescence microprobe trace element studies on spherules of the Cretaceous/Tertiary boundary transitions of NE-Mexico and Haiti samples

    Energy Technology Data Exchange (ETDEWEB)

    Kramar, Utz [Universitaet Karlsruhe (Thailand), Institut fuer Mineralogie und Geochemie, Kaiserstrasse 12, D-76128 Karlsruhe (Germany)], E-mail: utz.kramar@img.uni-karlsruhe.de; Harting, Markus [Utrecht University, Department of Earthsciences, Budapestlaan 4, 3508 TA Utrecht (Netherlands); Rickers, Karen [Hamburger Synchrotronstrahlungslabor HASYLAB at Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); GeoForschungsZentrum Potsdam, Division 4.1, Telegrafenberg, 14473 Potsdam (Germany); Stueben, Doris [Universitaet Karlsruhe (Thailand), Institut fuer Mineralogie und Geochemie, Kaiserstrasse 12, D-76128 Karlsruhe (Germany)

    2007-08-15

    Synchrotron radiation, collimated to a {mu}m scale was used for the determination of trace elements in micro-tektites and spherule material for the first time. The experimental set-up of the SXRF microprobe at beamline L at HASYLAB at DESY offers a suitable method for performing non-destructive in situ multi-element analysis focusing on spatial trace element distributions and mineral phases of the melted ejecta material from the Cretaceous/Tertiary boundary. The spatial distribution of trace elements was determined in melt inclusions as well as in phase transitions in selected parts of chlorite-smectite spherules and tektite glass material by using a beam with a diameter of 15 {mu}m collimated with a glass capillary for line- and area scans as well as for single point measurements for elements with Z between 19 and 92. The analyzed spherules show alteration features but also zonation and carbonate inclusions, originating from the Chicxulub impact event. These initial results demonstrate the potential of {mu}-SXRF analysis for the discrimination of alteration and primary signals of the spherules and re-construction of their genetic evolution. It could be shown that the spherules represent a complex mixture of different materials from the subsurface at the Chicxulub impact site.

  9. Radiative lifetimes of spin forbidden a1Δ → X3Σ- and spin allowed A3Π → X3Σ- transitions and complete basis set extrapolated ab initio potential energy curves for the ground and excited states of CH-.

    Science.gov (United States)

    Srivastava, Saurabh; Sathyamurthy, N

    2012-12-01

    The spin forbidden transition a(1)Δ → X(3)Σ(-) in CH(-) has been studied using the Breit-Pauli Hamiltonian for a large number of geometries. This transition acquires intensity through spin-orbit coupling with singlet and triplet Π states. The transition moment matrix including more than one singlet and triplet Π states was calculated at the multi-reference configuration interaction/aug-cc-pV6Z level of theory. The computed radiative lifetime of 5.63 s is in good agreement with the experimental (5.9 s) and other theoretical (6.14 s) results. Transition moment values of the spin allowed A(3)Π → X(3)Σ(-) transition have also been calculated at the same level of theory. Calculations show that the corresponding radiative lifetime is considerably low, 2.4 × 10(-7) s. Complete basis set extrapolated potential energy curves for the ground state of CH and the ground state and six low lying excited states (a(1)Δ, b(1)Σ(+), two (3)Π, and two (1)Π) of CH(-) are reported. These curves are then used to calculate the vibrational bound states for CH and CH(-). The computed electron affinity of CH supports the electron affinity bounds reported by Okumura et al. [J. Chem. Phys. 85, 1971 (1986)].

  10. Studies on radiation crosslinking of polysulfone

    Energy Technology Data Exchange (ETDEWEB)

    Zhong Xiaoguang; Sun Jiazhen [Changchun Inst. of Applied Chemistry, Chinese Academy of Sciences, Changchun (China)

    2000-03-01

    Polysulfone is a kind of high temperature-resistance and radiation-resistance engineering plastic. We studied radiation crosslinking effect of polysulfone by using of XPS, ESR, and CG methods and got some new results. Because of conjugate system of benzene ring, polymer material which contains of benzene ring will have a shake-up peak in XPS spectra. Comparing with radiation crosslinking at lower temperature, the intensity of shake-up peak increases with radiation dose when radiation crosslinking reaction takes place at temperature above glass transition temperature of polysulfone. It means that the mechanisms of radiation crosslinking of polysulfone at different radiation temperature are different above or below their glass transition temperature. Thus we can obtain a new method to characterize the degree of radiation crosslinking by the change of shake-up peaks. Furthermore, the mechanism of radiation crosslinking of polysulfone was studied from the behaviors of various radicals observed by ESR measurement. (J.P.N.)

  11. Radiation Therapy

    Science.gov (United States)

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

  12. Theory of edge radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, G.; Kocharyan, V.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

    2008-08-15

    We formulate a complete theory of Edge Radiation based on a novel method relying on Fourier Optics techniques. Similar types of radiation like Transition UndulatorRadiation are addressed in the framework of the same formalism. Special attention is payed in discussing the validity of approximations upon which the theory is built. Our study makes consistent use of both similarity techniques and comparisons with numerical results from simulation. We discuss both near and far zone. Physical understanding of many asymptotes is discussed. Based on the solution of the field equation with a tensor Green's function technique, we also discuss an analytical model to describe the presence of a vacuum chamber. In particular, explicit calculations for a circular vacuum chamber are reported. Finally, we consider the use of Edge Radiation as a tool for electron beam diagnostics. We discuss Coherent Edge Radiation, Extraction of Edge Radiation by a mirror, and other issues becoming important at high electron energy and long radiation wavelength. Based on this work we also study the impact of Edge Radiation on XFEL setups and we discuss recent results. (orig.)

  13. Radiation dosimetry

    CERN Document Server

    Hine, Gerald J; Hine, Gerald J

    1956-01-01

    Radiation Dosimetry focuses on the advancements, processes, technologies, techniques, and principles involved in radiation dosimetry, including counters and calibration and standardization techniques. The selection first offers information on radiation units and the theory of ionization dosimetry and interaction of radiation with matter. Topics include quantities derivable from roentgens, determination of dose in roentgens, ionization dosimetry of high-energy photons and corpuscular radiations, and heavy charged particles. The text then examines the biological and medical effects of radiation,

  14. Microwave-assisted synthesis of transition metal phosphide

    Science.gov (United States)

    Viswanathan, Tito

    2014-12-30

    A method of synthesizing transition metal phosphide. In one embodiment, the method has the steps of preparing a transition metal lignosulfonate, mixing the transition metal lignosulfonate with phosphoric acid to form a mixture, and subjecting the mixture to a microwave radiation for a duration of time effective to obtain a transition metal phosphide.

  15. Sustainable Transition

    DEFF Research Database (Denmark)

    Hansen, Ole Erik; Søndergård, Bent

    2014-01-01

    transition processes. Where. Addresses design processes aimed at sustainable transition enacted in complex social settings, socio-technical systems involving many different actors and agendas. How. The chapter outlines a conceptual and analytic framework for a reflexive design practice for sustainability...... including the perspective of structural changes (transition of socio-technical systems and social practices) and Design as metadesign; an reflexivity on contextual framework of the design practice (regimes/design spaces)....

  16. Variation of electronic transition moment versus internuclear distance for NO (A2∑→ X2∏) transition

    Institute of Scientific and Technical Information of China (English)

    Lianshui Zhang(张连水); Guiyin Zhang(张贵银); Xiaodong Yang(杨晓冬); Xiaohui Zhao(赵晓辉); Yi Li(李裔)

    2003-01-01

    Two-photon laser-induced fluorescence spectrum (TP-LIF) of NO is obtained with a Nd:YAG pumpedoptical parametric generator and amplifier as radiation source. Spectral intensity distribution shows thatthe electronic transition moment for NO (A2∑→ X2∏) transition varies significantly with inter-nucleardistance. The variation relationship of the electronic transition moment versus inter-nuclear distance isdeduced with polyminal fit procedure. The spontaneous radiative coefficients for NO (A2∑→ X2∏)transition from v′ = 0, 1 are obtained by combing this transition moment variation with the measurementsof spontaneous radiative lifetime.

  17. Phase transitions

    CERN Document Server

    Solé, Ricard V

    2011-01-01

    Phase transitions--changes between different states of organization in a complex system--have long helped to explain physics concepts, such as why water freezes into a solid or boils to become a gas. How might phase transitions shed light on important problems in biological and ecological complex systems? Exploring the origins and implications of sudden changes in nature and society, Phase Transitions examines different dynamical behaviors in a broad range of complex systems. Using a compelling set of examples, from gene networks and ant colonies to human language and the degradation o

  18. Measuring stellar granulation during planet transits

    CERN Document Server

    Chiavassa, A; Selsis, F; Leconte, J; Von Paris, P; Bordé, P; Magic, Z; Collet, R; Asplund, M

    2016-01-01

    Stellar activity and convection-related surface structures might cause bias in planet detection and characterization that use these transits. Surface convection simulations help to quantify the granulation signal. We used realistic three-dimensional radiative hydrodynamical simulations from the Stagger grid and synthetic images computed with the radiative transfer code Optim3D to model the transits of three prototype planets: a hot Jupiter, a hot Neptune, and a terrestrial planet. We computed intensity maps from RHD simulations of the Sun and a K-dwarf star at different wavelength bands from optical to far-infrared. We modeled the transit using synthetic stellar-disk images and emulated the temporal variation of the granulation intensity. We identified two types of granulation noise that act simultaneously during the planet transit: (i) the intrinsic change in the granulation pattern with timescales smaller than the usual planet transit, and (ii) the fact that the transiting planet occults isolated regions of...

  19. Radiation Therapy: Professions in Radiation Therapy

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Professions in Radiation Therapy Radiation Oncologist Therapeutic Medical Physicist Radiation Therapist Dosimetrist Radiation Oncology Nurse Social Worker Dietitian Radiation Oncologist Radiation oncologists are physicians who oversee the ...

  20. Many-Body Theory of Atomic Transitions

    Science.gov (United States)

    Holmes, Charles Potter

    This dissertation presents a systematic approach to the derivation of transition widths and cross sections for atomic radiative and/or nonradiative processes. By applying the transition theory of Goldberger and Watson ^1, all transition properties are derived from proper solutions of the time-dependent Schrodinger equation. The focus is on situations where initial and final wave functions are nonorthogonal functions that belong to different self-consistent fields. This approach is particularly useful in the treatment of ionizing transitions where the outgoing free electron sees a different atomic potential from that of the initial bound state. Transition amplitudes are expressed as perturbation expansions in which singularities have been removed algebraically. These singularities are due to states which are degenerate with the initial and final states and represent the competing transition channels. The perturbation expansions show clearly the role of the nonorthogonality of the participating states leading to terms representing "shake" processes competing with higher-order electron correlation processes. Transition amplitudes including all second-order processes, are derived for the following transitions: X-ray, Auger, photoionization, radiative recombination, dielectronic recombination, radiative -Auger. Comparisons are made with the expressions frequently used by other workers. Using a Hartree-Fock-Slater model K- and L-shell X-ray and Auger transition widths are calculated for the range 5 Z Theory, (John Wiley & Sons, New York, 1964), Chapter 8, page 424.

  1. γ-ray Intensity Calculation for Isomeric Transition Decay

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In an isomeric transition (it is called simply IT) decay, electromagnetic radiation of gamma-ray isemitted in the transitions of nucleus from a high exciting state to a lower states and ground state, and anatomic radiation can be emitted as an alternative to gamma-ray emission in the transition of nucleusthrough internal conversion electron (it is called simply Ce) process. In general, the IT decay gamma-rays

  2. Atoms, Radiation, and Radiation Protection

    CERN Document Server

    Turner, James E

    2007-01-01

    Atoms, Radiation, and Radiation Protection offers professionals and advanced students a comprehensive coverage of the major concepts that underlie the origins and transport of ionizing radiation in matter. Understanding atomic structure and the physical mechanisms of radiation interactions is the foundation on which much of the current practice of radiological health protection is based. The work covers the detection and measurement of radiation and the statistical interpretation of the data. The procedures that are used to protect man and the environment from the potential harmful effects of

  3. Radiative rates for E1, E2, M1, and M2 transitions among the 3s$^2$3p$^5$, 3s3p$^6$, and 3s$^2$3p$^4$3d configurations of Cl-like W LVIII

    CERN Document Server

    Aggarwal, K M

    2014-01-01

    We report calculations of energy levels, radiative decay rates, and lifetimes for transitions among the 3s$^2$3p$^5$, 3s3p$^6$, and 3s$^2$3p$^4$3d configurations of Cl-like W LVIII. The general-purpose relativistic atomic structure package (GRASP) has been adopted for our calculations. Comparisons are made with the most recent results of Mohan et al. [Can. J. Phys. {\\bf 92} (2014) xxx] and discrepancies in lifetimes are noted, up to four orders of magnitude in some instances. Our energy levels are estimated to be accurate to better than 0.5\\%, whereas results for radiative rates and lifetimes should be accurate to better than 20\\%.

  4. Tessellations & Transitions.

    Science.gov (United States)

    Cassidy, Joan

    1998-01-01

    Describes two sixth-grade lessons on the work of M. C. Escher: (1) the first lesson instructs students on tessellations, or tiles that interlock in a repeated pattern; (2) the second lesson explores Escher's drawings of transitions from two- to three-dimensional space. (DSK)

  5. Radiative transfer in silylidene molecule

    Directory of Open Access Journals (Sweden)

    Sharma M.

    2014-01-01

    Full Text Available In order to search for silylidene (H2CSi in the interstellar medium, Izuha et al. (1996 recorded microwave spectrum of H2CSi in laboratory and made an unsuccessful attempt of its identification in IRC +10216, Ori KL, Sgr B2, through its 717-616 transition at 222.055 GHz. For finding out if there are other transitions of H2CSi which may help in its identification in the interstellar medium, we have considered 25 rotational levels of ortho-H2CSi connected by collisional transitions and 35 radiative transitions, and solved radiative transfer problem using the LVG approximation. We have found that the brightness temperatures of 919-818, 918-817, 101,10-919, 1019-918, 111,11-101,10, 111,10-1019 and 121,12-111,11 transition are larger than that of 717-616 transition. Thus, these transitions may help in detection of H2CSi in the interstellar medium.

  6. Radiation effects on four polysulfone films

    Science.gov (United States)

    Santos, B.; Sykes, G. F.

    1981-01-01

    The response of polysulfones to proton and electron radiation is evaluated by assessing the radiation durability of four selected sulfones, establishing radiation interaction mechanisms with the polymer chain, and determining the dependence of radiation durability on chemical structure. Chain scission appears to predominate at lower doses up to about 10 to the 9th rad, and past this threshold the second mechanism, crosslinking, seems to predominate. This is evidenced by the increase in modulus, glass transition temperature, and increased quantity of thermally stable residue at high temperatures. The variations of chemical structure of the polysulfones appear to have little effect on the response to radiation.

  7. Radiation carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1976-01-01

    The risk of iatrogenic tumors with radiation therapy is so outweighed by the benefit of cure that estimates of risk have not been considered necessary. However, with the introduction of chemotherapy, combined therapy, and particle radiation therapy, the comparative risks should be examined. In the case of radiation, total dose, fractionation, dose rate, dose distribution, and radiation quality should be considered in the estimation of risk. The biological factors that must be considered include incidence of tumors, latent period, degree of malignancy, and multiplicity of tumors. The risk of radiation induction of tumors is influenced by the genotype, sex, and age of the patient, the tissues that will be exposed, and previous therapy. With chemotherapy the number of cells at risk is usually markedly higher than with radiation therapy. Clearly the problem of the estimation of comparative risks is complex. This paper presents the current views on the comparative risks and the importance of the various factors that influence the estimation of risk.

  8. Radiation acoustics

    CERN Document Server

    Lyamshev, Leonid M

    2004-01-01

    Radiation acoustics is a developing field lying at the intersection of acoustics, high-energy physics, nuclear physics, and condensed matter physics. Radiation Acoustics is among the first books to address this promising field of study, and the first to collect all of the most significant results achieved since research in this area began in earnest in the 1970s.The book begins by reviewing the data on elementary particles, absorption of penetrating radiation in a substance, and the mechanisms of acoustic radiation excitation. The next seven chapters present a theoretical treatment of thermoradiation sound generation in condensed media under the action of modulated penetrating radiation and radiation pulses. The author explores particular features of the acoustic fields of moving thermoradiation sound sources, sound excitation by single high-energy particles, and the efficiency and optimal conditions of thermoradiation sound generation. Experimental results follow the theoretical discussions, and these clearl...

  9. Hawking radiation

    Science.gov (United States)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  10. Radiation Damping at a Bubble Wall

    CERN Document Server

    Lee, J; Lee, C H; Jang, J; Lee, Jae-weon; Kim, Kyungsub; Lee, Chul H.; Jang, Ji-ho

    1999-01-01

    The first order phase transition proceeds via nucleation and growth of true vacuum bubbles. When charged particles collide with the bubble they could radiate electromagnetic wave. We show that, due to an energy loss of the particles by the radiation, the damping pressure acting on the bubble wall depends on the velocity of the wall even in a thermal equilibrium state.

  11. Radiative decays of negative parity heavy baryons in QCD

    CERN Document Server

    Agamaliev, A K; Savcı, M

    2016-01-01

    The transition form factors responsible for the radiative $\\Sigma_Q \\to \\Lambda_Q \\gamma$ and $\\Xi_Q^\\prime \\to \\Xi \\gamma$ decays of the negative parity baryons are examined within light cone QCD sum rules. The decay widths of the radiative transitions are calculated using the obtained results of the form factors.

  12. Overview of the Martian radiation environment experiment

    Energy Technology Data Exchange (ETDEWEB)

    Zeitlin, C.; Cleghorn, T.F.; Cucinotta, F.A.; Saganti, P.; Andersen, V.; Lee, K.T.; Pinsky, L.S.; Atwell, W.; Turner, R.; Badhwar, G.

    2004-12-01

    Space radiation presents a hazard to astronauts, particularly those journeying outside the protective influence of the geomagnetosphere. Crews on future missions to Mars will be exposed to the harsh radiation environment of deep space during the transit between Earth and Mars. Once on Mars, they will encounter radiation that is only slightly reduced, compared to free space, by the thin Martian atmosphere. NASA is obliged to minimize, where possible, the radiation exposures received by astronauts. Thus, as a precursor to eventual human exploration, it is necessary to measure the Martian radiation environment in detail. The MARIE experiment, aboard the 2001 Mars Odyssey spacecraft, is returning the first data that bear directly on this problem. Here we provide an overview of the experiment, including introductory material on space radiation and radiation dosimetry, a description of the detector, model predictions of the radiation environment at Mars, and preliminary dose-rate data obtained at Mars.

  13. Electromagnetic Radiation of Electrons in Periodic Structures

    CERN Document Server

    Potylitsyn, Alexander Petrovich

    2011-01-01

    Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...

  14. Transition Operators

    CERN Document Server

    Alcock-Zeilinger, Judith

    2016-01-01

    In this paper, we give a generic algorithm of the transition operators between Hermitian Young projection operators corresponding to equivalent irreducible representations of SU(N), using the compact expressions of Hermitian Young projection operators derived in a companion paper. We show that the Hermitian Young projection operators together with their transition operators constitute a fully orthogonal basis for the algebra of invariants of $V^{\\otimes m}$ that exhibits a systematically simplified multiplication table. We discuss the full algebra of invariants over $V^{\\otimes 3}$ and $V^{\\otimes 4}$ as explicit examples. In our presentation we make use of various standard concepts such as Young projection operators, Clebsch-Gordan operators, and invariants (in birdtrack notation). We tie these perspectives together and use them to shed light on each other.

  15. Design of a trigger layout and the corresponding implementation of a 200 GB/s readout network for the ALICE transition radiation detector; Entwicklung des Triggerkonzepts und die entsprechende Implementierung eines 200-GB/s-Auslesenetzwerks fuer den ALICE-Uebergangsstrahlungsdetektor

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Rolf

    2008-05-19

    Through the use of modern information technology, intelligent trigger systems are gaining more and more importance in high-energy physics. Particularly in heavy ion experiments, the large number of generated particles results in an enormous amount of data. By filtering the data at an early stage and discarding irrelevant events, the efficiency of the entire system can be raised significantly. The ALICE experiment at CERN breaks new ground in this respect. With the Transition Radiation Detector, the acquired signals are processed parallel right on the detector using more than 65 000 multi-chip modules. Via a readout network, the preprocessed data arrives at a global track reconstruction unit, which contributes to the decision whether an event is discarded or further processed. In this thesis, a trigger concept for the Transition Radiation Detector is developed and the readout network is implemented. A special challenge is to achieve an efficient interaction of the above processing stages. By means of simulations and analyses, the entire system is optimized in this regard. It turns out that the read-out process plays a decisive role. In this context, a design flow for the used ASIC is developed. The analyses show that through optimizations the extremely high demands made on this complex system can be met. During a beam time, first prototypes have successfully been tested. The entire system is currently being assembled and will be brought on line in 2008. (orig.)

  16. Proposed Radiation Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Davey, C. S.

    2004-07-01

    Current scientific evidence is that radiation at low levels is not harmful, but beneficial. This is borne out by both radiobiology and epidemiology. The ICRP 26 recommended limits of 50 mSv and 5 mSv per annum are comparable with the average natural background levels in Iran and Norway, respectively, and levels five times higher than that quoted for Iran are to be found in some populated parts of this world. The new limits proposed for ionising radiation are generated by comparison to existing recommended limits for essential minerals. There is a range of acceptable exposures to radiation, just as there is for minerals. The replacement for the ICRP 60 recommendations (20 mSv and 1 mSv for radiation workers and public respectively) should be higher limits of 200 mSv and 50 mSv. There should also be minimum recommended annual levels of 10 mSv, for both radiation workers and the public. The consequences of not proposing this change are continuing huge negative impacts to society. In cancer therapy, even the older guidelines caused unnecessary expense and delays. The cost to Canada is astronomical, when one considers the effect of the existing limits on the use of nuclear power, and the resulting use of hydrocarbons and the consequent increase in acid rain, etc. Of course, the same thing can be said of the entire world limited funds are diverted from areas where they would be better applied, and alternative solutions to societal needs are implemented, solutions which increase pollution and cause injury and death. It is time to reverse the current, expensive trend into misapplied ALARA, based on the paranoia about all things nuclear, which has developed since the linear no-threshold hypothesis was first proposed.propose the transition to a realistic and balanced approach to ionising radiation. (Author)

  17. Dark Radiative Inverse Seesaw

    CERN Document Server

    Ahriche, Amine; Nasri, Salah

    2016-01-01

    We present a minimal model that simultaneously accounts for neutrino masses and the origin of dark matter (DM) and where the electroweak phase transition is strong enough to allow for electroweak baryogenesis. The Standard Model is enlarged with a Majorana fermion, three generations of chiral fermion pairs, and a single complex scalar that plays a central role in DM production and phenomenology, neutrino masses, and the strength of the phase transition. All the new fields are singlets under the SM gauge group. Neutrino masses are generated via a new variant of radiative inverse seesaw where the required small mass term is generated via loops involving DM and no large hierarchy is assumed among the mass scales. The model offers all the advantage of low-scale neutrino mass models as well as a viable dark matter candidate that is testable with direct detection experiments.

  18. Transit space

    DEFF Research Database (Denmark)

    Raahauge, Kirsten Marie

    2008-01-01

    This article deals with representations of one specific city, Århus, Denmark, especially its central district. The analysis is based on anthropological fieldwork conducted in Skåde Bakker and Fedet, two well-off neighborhoods. The overall purpose of the project is to study perceptions of space...... and the interaction of cultural, social, and spatial organizations, as seen from the point of view of people living in Skåde Bakker and Fedet. The focus is on the city dwellers’ representations of the central district of Århus with specific reference to the concept of transit space. When applied to various Århusian...

  19. Conformational Transitions

    Science.gov (United States)

    Czerminski, Ryszard; Roitberg, Adrian; Choi, Chyung; Ulitsky, Alexander; Elber, Ron

    1991-10-01

    Two computational approaches to study plausible conformations of biological molecules and the transitions between them are presented and discussed. The first approach is a new search algorithm which enhances the sampling of alternative conformers using a mean field approximation. It is argued and demonstrated that the mean field approximation has a small effect on the location of the minima. The method is a combination of the LES protocol (Locally Enhanced Sampling) and simulated annealing. The LES method was used in the past to study the diffusion pathways of ligands from buried active sites in myoglobin and leghemoglobin to the exterior of the protein. The present formulation of LES and its implementation in a Molecular Dynamics program is described. An application for side chain placement in a tetrapeptide is presented. The computational effort associated with conformational searches using LES grows only linearly with the number of degrees of freedom, whereas in the exact case the computational effort grows exponentially. Such saving is of course associated with a mean field approximation. The second branch of studies pertains to the calculation of reaction paths in large and flexible biological systems. An extensive mapping of minima and barriers for two different tetrapeptides is calculated from the known minima and barriers of alanine tetrapeptide which we calculated recently.1 The tetrapeptides are useful models for the formation of secondary structure elements since they are the shortest possible polymers of this type which can still form a complete helical turn. The tetrapeptides are isobutyryl-val(χ1=60)-ala-ala and isobutyryl-val(χ1=-60)-ala-ala. Properties of the hundreds of minima and of the hundreds intervening barriers are discussed. Estimates for thermal transition times between the many conformers (and times to explore the complete phase space) are calculated and compared. It is suggested that the most significant effect of the side chain size is

  20. Thermodynamics of Phase Transitions of a Kerr Nonlinear Blackbody

    Institute of Scientific and Technical Information of China (English)

    CHENG Ze

    2008-01-01

    We study the thermodynamics of phase transitions of a blackbody whose interior is filled by a Kerr nonlinear crystal. There is a transition temperature To, above which the Kerr nonlinear blackbody is in the normal thermal radiation state, and below which it is in the squeezed thermal radiation state. At To, the Gibbs free energy of the two phases is continuous but the entropy density of the two phases is discontinuous. Hence, there is a jump in the entropy density and this leads to a latent heat density. The photon system undergoes a first-order phase transition from the normal to the squeezed thermal radiation state.

  1. The nature of transition blazars

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, J. J.; Anderson, S. F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Plotkin, R. M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Brandt, W. N.; Schneider, D. P. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Burnett, T. H. [Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States); Myers, A. D., E-mail: jruan@astro.washington.edu [Department of Physics and Astronomy 3905, University of Wyoming, 1000 East University, Laramie, WY 82071 (United States)

    2014-12-10

    Blazars are classically divided into the BL Lacertae (BLL) and flat-spectrum radio quasar (FSRQ) subclasses, corresponding to radiatively inefficient and efficient accretion regimes, respectively, largely based on the equivalent width (EW) of their optical broad emission lines (BELs). However, EW-based classification criteria are not physically motivated, and a few blazars have previously transitioned' from one subclass to the other. We present the first systematic search for these transition blazars in a sample of 602 unique pairs of repeat spectra of 354 blazars in the Sloan Digital Sky Survey, finding six clear cases. These transition blazars have bolometric Eddington ratios of ∼0.3 and low-frequency synchrotron peaks, and are thus FSRQ-like. We show that the strong EW variability (up to an unprecedented factor of >60) is due to swamping of the BELs from variability in jet continuum emission, which is stronger in amplitude and shorter in timescale than typical blazars. Although these transition blazars appear to switch between FSRQ and BLL according to the phenomenologically based EW scheme, we show that they are most likely rare cases of FSRQs with radiatively efficient accretion flows and especially strongly beamed jets. These results have implications for the decrease of the apparent BLL population at high redshifts, and may lend credence to claims of a negative BLL redshift evolution.

  2. Comparative Habitability of Transiting Exoplanets

    CERN Document Server

    Barnes, Rory; Evans, Nicole

    2015-01-01

    Exoplanet habitability is traditionally assessed by comparing a planet's semi-major axis to the location of its host star's "habitable zone," the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an "eccentricity-albedo degeneracy" for the habitability of transiti...

  3. Radiation Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Castor, J I

    2003-10-16

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is

  4. Radiation damage

    CERN Document Server

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  5. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  6. Radiation Protection

    Energy Technology Data Exchange (ETDEWEB)

    Loos, M

    2001-04-01

    Major achievements of SCK-CEN's Radiation Protection Department in 2000 are described. The main areas for R and D of the department remain neutron dosimetry and neutron activation analysis, safeguards information handling and non-destructive assay techniques. Further activities include low-level radioactivity measurements in environmental and biological samples and radiation protection research. Finally, achievements in decision strategy research and social sciences in nuclear research are reported.

  7. Synchrotron radiation with radiation reaction

    Science.gov (United States)

    Nelson, Robert W.; Wasserman, Ira

    1991-04-01

    A rigorous discussion is presented of the classical motion of a relativistic electron in a magnetic field and the resulting electromagnetic radiation when radiation reaction is important. In particular, for an electron injected with initial energy gamma(0), a systematic perturbative solution to the Lorentz-Dirac equation of motion is developed for field strengths satisfying gamma(0) B much less than 6 x 10 to the 15th G. A particularly accurate solution to the electron orbital motion in this regime is found and it is demonstrated how lowest-order corrections can be calculated. It is shown that the total energy-loss rate corresponds to what would be found using the exact Larmor power formula without including radiation reaction. Provided that the particle energy and field strength satisfy the same contraint, it is explicitly demonstrated that the intuitive prescription for calculating the time-integrated radiation spectrum described above is correct.

  8. Radiation Therapy (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Radiation Therapy KidsHealth > For Parents > Radiation Therapy Print A ... have many questions and concerns about it. About Radiation Therapy In radiation therapy, high-energy radiation from ...

  9. Abdominal radiation - discharge

    Science.gov (United States)

    Radiation - abdomen - discharge; Cancer - abdominal radiation; Lymphoma - abdominal radiation ... When you have radiation treatment for cancer, your body goes through changes. About 2 weeks after radiation treatment starts, you might notice changes ...

  10. Brain radiation - discharge

    Science.gov (United States)

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  11. Observation of the 2p{sub 3/2}-2s{sub 1/2} radiative transition in Li-like uranium using the resonant coherent excitation in Si-crystal.

    Energy Technology Data Exchange (ETDEWEB)

    Ananyeva, Alena [Goethe Universitaet Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Azuma, Toshiyuki; Nakano, Yuji [Tokyo Metropolitan University (Japan); RIKEN, Tokyo (Japan); Braeuning, Harald; Braeuning-Demian, Angela; Dimopoulou, Christina; Kleffner, Carl; Steck, Markus [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Dauvergne, Denis [IPNL - Institut de Physique Nucleaire de' Lyon (France); Kanai, Yasuyuki [RIKEN, Tokyo (Japan); Pivovarov, Yuri [National ResearchTomsk Polytechnic University (Russian Federation); Suda, Shintaro [Tokyo Metropolitan University (Japan); Yamazaki, Yasunori [RIKEN, Tokyo (Japan); University of Tokyo (Japan)

    2012-07-01

    Taking advantage of the cooled, relativistic ion beams delivered by the Experimental Storage Ring (ESR) at GSI, Darmstadt the energy of the 1s{sup 2}2p{sub 3/2}- 1s{sup 2}2s{sub 1/2} transition in Li-like U ions was measured by using the resonant excitation of ions in a Si-crystal in channelling conditions. The excitation of the projectile traversing a solid target with an ordered structure is induced with great probability by the periodic potential defined by the atoms of the crystal lattice when the oscillation frequency of the crystal field fits the energy difference between two levels of the ion. The resonant character of the process enables the determination of transition energy with high precision. The present scheme is quite universal being applicable for various ions and for a wide range of transition energies in the field of atomic as well as nuclear physics.

  12. QCD Multipole Expansion and Hadronic Transitions in Heavy Quarkonium Systems

    Institute of Scientific and Technical Information of China (English)

    KUANG Yu-ping

    2006-01-01

    We review the developments of the multipole expansion approach in quantum chromodynamics and its applications to hadronic transitions and some radiative decays of heavy quarkonia.Theoretical predictions are compared with updated experimental results.

  13. Polarization in cyclotron radiation in strong magnetic fields

    Institute of Scientific and Technical Information of China (English)

    Luidmila Semionova; Denis Leahy; Jorge Paez

    2010-01-01

    We revisit the problem of radiative transitions of electrons in the presence of a strong magnetic field.We derive fully relativistic cyclotron transition rates for an arbitrary magnetic field,for any orientation of electron spin and for any polarization of the emitted radiation.Also,we obtain the transition rates for any value of the initial electron's parallel momentum.For very strong magnetic fields,transitions to the ground state predominate.Transition rates summed over the electron's spin orientation and for unpolarized radiation are also obtained,which confirm previous results by Latal.Transition widths are calculated for different electron spin orientations and different polarizations of radiation.We obtain general expressions for transition rates that reduce to the results for the non-relativistic case and for unpolarized radiation.Additionally we get,for the non-relativistic approximation,the transition rates for any polarization of radiation.As an application,the first five emission lines are evaluated and compared to the X-ray emitting neutron star V0332+53,which has multiple observable cyclotron lines,taking into account gravitational redshift.The most probable polarization is ∈(2).

  14. COMPARATIVE HABITABILITY OF TRANSITING EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Rory; Meadows, Victoria S.; Evans, Nicole, E-mail: rory@astro.washington.edu [Astronomy Department, University of Washington, Box 951580, Seattle, WA 98195 (United States)

    2015-12-01

    Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass–radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.

  15. Comparative Habitability of Transiting Exoplanets

    Science.gov (United States)

    Barnes, Rory; Meadows, Victoria S.; Evans, Nicole

    2015-12-01

    Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass-radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.

  16. Relativistic Radiation Mediated Shocks

    CERN Document Server

    Budnik, Ran; Sagiv, Amir; Waxman, Eli

    2010-01-01

    The structure of relativistic radiation mediated shocks (RRMS) propagating into a cold electron-proton plasma is calculated and analyzed. A qualitative discussion of the physics of relativistic and non relativistic shocks, including order of magnitude estimates for the relevant temperature and length scales, is presented. Detailed numerical solutions are derived for shock Lorentz factors $\\Gamma_u$ in the range $6\\le\\Gamma_u\\le30$, using a novel iteration technique solving the hydrodynamics and radiation transport equations (the protons, electrons and positrons are argued to be coupled by collective plasma processes and are treated as a fluid). The shock transition (deceleration) region, where the Lorentz factor $ \\Gamma $ drops from $ \\Gamma_u $ to $ \\sim 1 $, is characterized by high plasma temperatures $ T\\sim \\Gamma m_ec^2 $ and highly anisotropic radiation, with characteristic shock-frame energy of upstream and downstream going photons of a few~$\\times\\, m_ec^2$ and $\\sim \\Gamma^2 m_ec^2$, respectively.P...

  17. State Transitions of Black Hole Accretion Flows

    Institute of Scientific and Technical Information of China (English)

    卢炬甫; 潘刘彬

    2001-01-01

    We show that the thermal instability-triggered transition from the state of the Shakura-Sunyaev disc to the state of the advection-dominated accretion flow is possible for black hole accretion flows composed of two-temperature plasma with bremsstrahlung and synchrotron radiation and Comptonization.

  18. Atmospheric radiation flight dose rates

    Science.gov (United States)

    Tobiska, W. K.

    2015-12-01

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has been conducting space weather observations of the atmospheric radiation environment at aviation altitudes that will eventually be transitioned into air traffic management operations. The Automated Radiation Measurements for Aerospace Safety (ARMAS) system and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) both are providing dose rate measurements. Both activities are under the ARMAS goal of providing the "weather" of the radiation environment to improve aircraft crew and passenger safety. Over 5-dozen ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. Flight altitudes now exceed 60,000 ft. and extend above commercial aviation altitudes into the stratosphere. In this presentation we describe recent ARMAS and USEWX results.

  19. Cherenkov radiation; La radiation Cerenkov

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    When the radioactivity has been discovered, it was observed by researchers that different materials as mineral salts or solutions were emitting a weak light when submitted to radioactivity beams. At the beginning it has been thought that it was fluorescent light. In 1934, Cherenkov, a russian physicist, worked on the luminescence of uranyl salts solutions caused by gamma radiation and observed a very weak light was emitted by pure liquid. After further studies, he concluded that this phenomena was different from fluorescence. Since then, it has been called Cherenkov effect. This blue light emission is produced when charged particles are going through a transparent medium with an upper velocity than light velocity. This can happen only in medium with large refractive index as water or glass. It also presents its different properties discovered afterwards. The different applications of the Cherenkov radiation are discussed as counting techniques for radiation detectors or comic ray detectors. (M.P.)

  20. Trends In Materials Processing With Laser Radiation

    Science.gov (United States)

    Herziger, G.; Kreutz, E. W.

    1989-04-01

    The objectives of reactive chemical and nonreactive thermal processing with laser radiation are outlined giving indication that processing with laser radiation is governed by a hierarchy of time constants originating from photon-matter interaction, phase transition dynamics, laser source excitation fluctuations,, and optical feedback in combination with the influence of beam delivery systems, processing/shielding gas flow configurations, robotics, production lines and environment. The minimization of losses by heat flow, reflection and transmission and the stringent need for quality assurance require as first approach the control of processing, which is mainly due to the capability of laser radiation source. The current status of laser radiation sources is reported giving information on the state of the art of processing with laser radiation in combination with subsequent demonstration of future trends and developments with respect to radiation sources, beam delivery, beam shaping, materials, processing and quality assurance.

  1. Trends in materials processsing with laser radiation

    Science.gov (United States)

    Herziger, Gerd; Kreutz, Ernst W.

    1989-03-01

    The objectives of reactive chemical and nonreactive thermal processing with laser radiation are outlined giving indication that processing with laser radiation is governed by a hierarchy of time constants originating from photon-matter interaction, phase transition dynamics, laser source excitation fluctuations, and optical feedback in combination with the influence of beam delivery systems, processing/shielding gas flow configurations, robotics, production lines and environment. The minimization of losses by heat flow, reflection and transmission and the stringent need for quality assurance require as first approach the control of processing, which is mainly due to the capability of laser radiation source. The current status of laser radiation sources is reported giving information on the state of the art of processing with laser radiation in combination with subsequent demonstration of future trends and developments with respect to radiation sources, beam delivery, beam shaping, materials, processing and quality assurance.

  2. Thermal effects on the network structure of diglycidylether of bisphenol-A polymerized by electron-beam in the presence of an iodonium salt[Cationic polymerization; Epoxy monomers; Glass transition; Network properties; Radiation curing

    Energy Technology Data Exchange (ETDEWEB)

    Degrand, H.; Cazaux, F.; Coqueret, Xavier E-mail: xavier.coqueret@univ-lille1.fr; Defoort, Brigitte; Boursereau, F.; Larnac, Guy

    2003-12-01

    The cationic polymerization of diglycidylether of bisphenol A (DGEBA) initiated in the presence of a diaryliodonium salt (DAIS) by electron beam irradiation has been studied by FTIR spectroscopy and by dynamic mechanical thermal analysis (DMA). The obtained results show the gradual increase of the temperature for the network thermo-mechanical transition (T{sub {alpha}}, associated with the glass transition temperature T{sub g}) over a broad range of conversion ({pi}) and reveal a peculiar behavior at high conversion. In this domain ({pi}>0.90), the material's T{sub g} is shown to decrease when conversion approaches unity. Moreover, the post-irradiation thermal treatment of the materials, that generally yields effective post-polymerization, appears to induce a decrease of T{sub g}, with an amplitude correlated with the amount of DAIS in the formulation. Owing to the particular nature of the propagating centers in cationic polymerization, the thermal relaxation of ionic clusters trapped in the glassy matrix can be reasonably invoked as a possible cause for this behavior.

  3. The high frequency acoustic radiation from the boundary layer of an axisymmetric body

    Institute of Scientific and Technical Information of China (English)

    LI Fuxin; MA Lin; MA Zhiming

    2001-01-01

    The mechanism of acoustic radiation from the boundary layer of an axisymmetric body is analyzed, and its sound pressure spectrum is predicted. It is shown that the acoustic radiation results from the transition region and the turbulent boundary layer; and that the acoustic radiation from transition region is predominant at low frequencies; while the turbulent boundary layer has the decisive effect on acoustic radiation at high frequencies. The calculated values are in good agreement with the experimental data.

  4. Radiation Technology Against Bioterrorism

    Science.gov (United States)

    2004-10-25

    application of radiation processing: radiation crosslinking of polymers and radiation sterilization of health care products have developed into substantial...municipal waste water, • radiation inactivation of bioterrorism agents, • electron beam processing of flue gases, • radiation crosslinking , • radiation...Electron beam processing of flue gases 6. Radiation crosslinking 7. Radiation curing 3 Radiation Technology Against Bioterrorism L.G. Gazsó and G

  5. Earth's Atmospheric Electricity Parameter Response During Venus Transit

    Directory of Open Access Journals (Sweden)

    Syam Sundar De

    2015-01-01

    Full Text Available Venus transited across the Sun on 06 June 2012, introducing significant contribution to the tidal characteristics of the solar atmosphere. _ atmosphere was perturbed due to an anomalous Coronal Mass Ejection (CME and γ-radiationγ-radiation influenced by the solar tide due to Venus transit, thereby the Earth-ionosphere waveguide characteristics were changed. In this anomalous situation we measured some atmospheric electricity parameters such as Schumann resonance (SR amplitude, very low frequency (VLF sferics, subionospheric transmitted signals and the point discharge current (PDC along with the vertical electrical potential gradient (PG at the ground surface on the day of transit. The results showed some remarkable variations during the transit as well as pre- and post-transit periods. The observed anomalies in the recorded data were interpreted in terms of the anomalous solar tidal effects initiated due to Venus transit.

  6. Sm Transition Probabilities and Abundances

    CERN Document Server

    Lawler, J E; Sneden, C; Cowan, J J

    2005-01-01

    Radiative lifetimes, accurate to +/- 5%, have been measured for 212 odd-parity levels of Sm II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier-transform spectrometry to determine transition probabilities for more than 900 lines of Sm II. This work is the largest-scale laboratory study to date of Sm II transition probabilities using modern methods. This improved data set has been used to determine a new solar photospheric Sm abundance, log epsilon = 1.00 +/- 0.03, from 26 lines. The spectra of three very metal-poor, neutron-capture-rich stars also have been analyzed, employing between 55 and 72 Sm II lines per star. The abundance ratios of Sm relative to other rare earth elements in these stars are in agreement, and are consistent with ratios expected from rapid neutron-capture nucleosynthesis (the r-process).

  7. PyTransit: Transit light curve modeling

    Science.gov (United States)

    Parviainen, Hannu

    2015-05-01

    PyTransit implements optimized versions of the Giménez and Mandel & Agol transit models for exoplanet transit light-curves. The two models are implemented natively in Fortran with OpenMP parallelization, and are accessed by an object-oriented python interface. PyTransit facilitates the analysis of photometric time series of exoplanet transits consisting of hundreds of thousands of data points, and of multipassband transit light curves from spectrophotometric observations. It offers efficient model evaluation for multicolour observations and transmission spectroscopy, built-in supersampling to account for extended exposure times, and routines to calculate the projected planet-to-star distance for circular and eccentric orbits, transit durations, and more.

  8. Radiation protection

    CERN Multimedia

    Radioactive Shipping Service

    2005-01-01

    The section of the radiation protection group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tél. 73171

  9. Radiation protection

    CERN Document Server

    2005-01-01

    The section of the Radiation Protection Group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tel. 73171

  10. Radiation protection

    CERN Multimedia

    2005-01-01

    The section of the Radiation Protection Group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tél. 73171

  11. Radiatively Generated $\

    CERN Document Server

    Joshipura, A S; Joshipura, Anjan S.; Rindani, Saurabh D.

    2003-01-01

    We study the consequences of assuming that the mass scale $\\Delta_{odot}$ corresponding to the solar neutrino oscillations and mixing angle $U_{e3}$ corresponding to the electron neutrino oscillation at CHOOZ are radiatively generated through the standard electroweak gauge interactions. All the leptonic mass matrices having zero $\\Delta_{odot}$ and $U_{e3}$ at a high scale lead to a unique low energy value for the $\\Delta_{odot}$ which is determined by the (known) size of the radiative corrections, solar and the atmospheric mixing angle and the Majorana mass of the neutrino observed in neutrinoless double beta decay. This prediction leads to the following consequences: ($i$) The MSSM radiative corrections generate only the dark side of the solar neutrino solutions. ($ii$) The inverted mass hierarchy ($m,-m,0$) at the high scale fails in generating the LMA solution but it can lead to the LOW or vacuum solutions. ($iii$) The $\\Delta_{odot}$ generated in models with maximal solar mixing at a high scale is zero t...

  12. Chest radiation - discharge

    Science.gov (United States)

    Radiation - chest - discharge; Cancer - chest radiation; Lymphoma - chest radiation ... When you have radiation treatment for cancer, your body goes through changes. About 2 weeks after your first treatment: It may be hard ...

  13. Risk Factors: Radiation

    Science.gov (United States)

    Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage DNA and cause cancer. Ionizing radiation includes radon, x-rays, gamma rays, and other forms of high-energy radiation.

  14. Acute Radiation Syndrome

    Science.gov (United States)

    ... Matters Information on Specific Types of Emergencies Acute Radiation Syndrome (ARS): A Fact Sheet for the Public ... is called the radiation dose. People exposed to radiation will get ARS only if: The radiation dose ...

  15. Radiation Engineering for Designers

    Science.gov (United States)

    Pellish, Jonathan A.

    2015-01-01

    This tutorial provides an overview of the natural space radiation environment, an introduction to radiation effect types, an overview of EEE parts selection, scrubbing, and radiation mitigation, and an introduction to radiation testing.

  16. System Geometries and Transit/Eclipse Probabilities

    Directory of Open Access Journals (Sweden)

    Howard A.

    2011-02-01

    Full Text Available Transiting exoplanets provide access to data to study the mass-radius relation and internal structure of extrasolar planets. Long-period transiting planets allow insight into planetary environments similar to the Solar System where, in contrast to hot Jupiters, planets are not constantly exposed to the intense radiation of their parent stars. Observations of secondary eclipses additionally permit studies of exoplanet temperatures and large-scale exo-atmospheric properties. We show how transit and eclipse probabilities are related to planet-star system geometries, particularly for long-period, eccentric orbits. The resulting target selection and observational strategies represent the principal ingredients of our photometric survey of known radial-velocity planets with the aim of detecting transit signatures (TERMS.

  17. Space radiation protection: Destination Mars

    Science.gov (United States)

    Durante, Marco

    2014-04-01

    National space agencies are planning a human mission to Mars in the XXI century. Space radiation is generally acknowledged as a potential showstopper for this mission for two reasons: a) high uncertainty on the risk of radiation-induced morbidity, and b) lack of simple countermeasures to reduce the exposure. The need for radiation exposure mitigation tools in a mission to Mars is supported by the recent measurements of the radiation field on the Mars Science Laboratory. Shielding is the simplest physical countermeasure, but the current materials provide poor reduction of the dose deposited by high-energy cosmic rays. Accelerator-based tests of new materials can be used to assess additional protection in the spacecraft. Active shielding is very promising, but as yet not applicable in practical cases. Several studies are developing technologies based on superconducting magnetic fields in space. Reducing the transit time to Mars is arguably the best solution but novel nuclear thermal-electric propulsion systems also seem to be far from practical realization. It is likely that the first mission to Mars will employ a combination of these options to reduce radiation exposure.

  18. Search for time-dependent fluctuations in cosmic ray flux with the AMS-01 detector and construction of the AMS-02 detector

    CERN Document Server

    Paniccia, Mercedes

    La découverte au début du vingtième siècle de l’existence d’un flux de particules énergétiques provenant de l’espace a engendré un vif intérêt auprès de la communauté scientifique de l’époque, donnant naissance à de nouvelles branches d’étude, dont la physique des particules est l’exemple le plus éclatant. La formulation d’un modèle pouvant expliquer l’origine et le spectre du rayonnement cosmique et aussi décrire les mécanismes de propagation et d’accélération dans l’espace interstellaire et interplanétaire, a nécessité l’effort conjoint de différents domaines: la physique des particules, la physique des plasmas, l’astrophysique, la physique solaire et la géophysique. L’analyse de l’enorme quantité de données collectées au sujet de rayons cosmiques au moyen de détecteurs au sol, en ballon et dans l’espace, combinée avec les observations des événements astrophysiques, solaires et géophysiques, a permis d’expliquer la plupart des propriétés des...

  19. Intense terahertz radiation from relativistic laser-plasma interactions

    Science.gov (United States)

    Liao, G. Q.; Li, Y. T.; Li, C.; Liu, H.; Zhang, Y. H.; Jiang, W. M.; Yuan, X. H.; Nilsen, J.; Ozaki, T.; Wang, W. M.; Sheng, Z. M.; Neely, D.; McKenna, P.; Zhang, J.

    2017-01-01

    The development of tabletop intense terahertz (THz) radiation sources is extremely important for THz science and applications. This paper presents our measurements of intense THz radiation from relativistic laser-plasma interactions under different experimental conditions. Several THz generation mechanisms have been proposed and investigated, including coherent transition radiation (CTR) emitted by fast electrons from the target rear surface, transient current radiation at the front of the target, and mode conversion from electron plasma waves (EPWs) to THz waves. The results indicate that relativistic laser plasma is a promising driver of intense THz radiation sources.

  20. Atomic clocks with suppressed blackbody radiation shift

    CERN Document Server

    Yudin, V I; Okhapkin, M V; Bagayev, S N; Tamm, Chr; Peik, E; Huntemann, N; Mehlstaubler, T E; Riehle, F

    2011-01-01

    We develop a nonstandard concept of atomic clocks where the blackbody radiation shift (BBRS) and its temperature fluctuations can be dramatically suppressed (by one to three orders of magnitude) independent of the environmental temperature. The suppression is based on the fact that in a system with two accessible clock transitions (with frequencies $\

  1. Results of the phase II EORTC 22971 trial evaluating combined accelerated external radiation and chemotherapy with 5FU and cisplatin in patients with muscle invasive transitional cell carcinoma of the bladder

    Energy Technology Data Exchange (ETDEWEB)

    Poortmans, Philip M. (Dept. of Radiation Oncology, Dr. Bernard Verbeeten Inst., Tilburg (NL)); Van Der Hulst, Marleen; Richaud, Pierre (Dept. of Radiation Oncology, Inst. Bergonieacute, Bordeaux (France)); Collette, Laurence; Pierart, Marianne (Statistics Dept., EORTC Data Center, Brussels (Belgium)); Ho Goey, S. (Dept. of Medical Oncology, TweeSteden Hospital, Tilburg (NL)); Bolla, Michel (Dept. of Radiation Oncology, CHU, Grenoble (France))

    2008-06-15

    Introduction. We prospectively evaluated concomitant radiotherapy and chemotherapy for advanced bladder cancer in a phase II EORTC trial to test whether it could be further studied as a potential treatment of bladder cancer. Patients and methods. Patients up to 75 years of age with invasive transitional-cell carcinoma of the bladder up to 5 cm, stage pT2 to pT3b, N0M0, without residual macroscopical tumour after transurethral excision were eligible. Radiotherapy consisted of 2 fractions of 1.2 Gy daily up to 60 Gy delivered in a period of 5 weeks. During the first and the last week, cisplatin 20 mg/m2/day and 5 FU 375 mg/m2/day were given concomitantly. Results. The study was interrupted early due to poor recruitment. Nine patients of the originally 43 planned were treated. Mean age was 63 years. Five patients had tumour stage pT2, 1 stage pT3a and 3 stage pT3b. All patients completed radiotherapy and chemotherapy as scheduled. Only one grade 3 and no grade 4 toxicity was seen. All patients were evaluated 3 months after treatment: eight patients had no detectable tumour and one had para-aortic lymph nodes. During further follow-up, a second patient got lymph node metastases and two patients developed distant metastases (lung in the patient with enlarged lymph nodes at the first evaluation and abdominal in one other). Those three patients died at respectively 19, 14, and 18 months after registration. Late toxicity was limited and often temporary. After 26 to 57 months of follow-up, no local recurrences were seen. Six patients remained alive without disease. Discussion. Despite the small cohort, this combination of concomitant chemotherapy and accelerated hyperfractionated radiotherapy for invasive bladder cancer seemed to be well tolerated and to result in satisfactory local control with limited early and late toxicity. It could therefore be considered for study in further clinical trials

  2. On Hawking Radiation of 3D Rotating Hairy Black Holes

    CERN Document Server

    Belhaj, A; Moumni, H EL; Masmar, K; Sedra, M B

    2015-01-01

    We study the Hawking radiation of 3D rotating hairy black holes. More concretely, we compute the transition probability of a bosonic and fermionic particle in such backgrounds. Thew, we show that the transition probability is independent of the nature of the particle. It is observed that the charge of the scalar hair B and the rotation parameter a control such a probability.

  3. Atomic transition probabilities of Nd I

    Science.gov (United States)

    Stockett, M. H.; Wood, M. P.; Den Hartog, E. A.; Lawler, J. E.

    2011-12-01

    Fourier transform spectra are used to determine emission branching fractions for 236 lines of the first spectrum of neodymium (Nd i). These branching fractions are converted to absolute atomic transition probabilities using radiative lifetimes from time-resolved laser-induced fluorescence measurements (Den Hartog et al 2011 J. Phys. B: At. Mol. Opt. Phys. 44 225001). The wavelength range of the data set is from 390 to 950 nm. These transition probabilities from emission and laser measurements are compared to relative absorption measurements in order to assess the importance of unobserved infrared branches from selected upper levels.

  4. Radiation pneumonitis

    Energy Technology Data Exchange (ETDEWEB)

    Amla, T.R.; Chakravarti, R.N.; Lal, K.

    1975-07-01

    Adult healthy rhesus monkeys were exposed to a course of roentgen irradiation over the chest and back to produce pulmonary changes simulating human radiation pneumonitis. Macroscopic and morphologic changes included dense adhesions, pleural thickening and increased consistency of the lungs. Microscopically the early reaction was characterized by dilatation of pulmonary vessels, microhaemorrhages, collapse of alveoli, permeation of the interstitial tissue with a fibrinous fluid and cells. In the late stage the fibrinous interstitial matrix was replaced by hyaline eosinophilic mass, fragmentation and dissolution of the elastic tissue and thickening of the alveolar walls. The cell population in the interstitial tissue showed decline and at places radiolytic effect. There was peribronchial and perivascular fibrosis and hyalinization and pulmonary arteries revealed marked degree of arteriosclerosis. The present study opens a new field for experimental research on the development of pulmonary hypertension as a post-irradiation complication.

  5. Radiation Insulation

    Science.gov (United States)

    1995-01-01

    The Apollo and subsequent spacecraft have had highly effective radiation barriers; made of aluminized polymer film, they bar or let in heat to maintain consistent temperatures inside. Tech 2000, formerly Quantum International Corporation used the NASA technology in its insulating materials, Super "Q" Radiant Barrier, for home, industry and mobile applications. The insulation combines industrial aluminum foil overlaid around a core of another material, usually propylene or mylar. The outer layer reflects up to 97 percent of heat; the central layer creates a thermal break in the structure and thus allows low radiant energy emission. The Quantum Cool Wall, used in cars and trucks, takes up little space while providing superior insulation, thus reducing spoilage and costs. The panels can also dampen sound and engine, exhaust and solar heat.

  6. ON THE FREQUENCY SPECTRUM OF TSUNAMI RADIATION

    Directory of Open Access Journals (Sweden)

    Frank C Lin

    2015-07-01

    Full Text Available We have measured the spectrum of the tsunami radiation at the following wavelengths: 0.73 μm, 10.8μm, 12.0μm, 6.8μm and 3.8 μm (or 13,698 cm-1, 925 cm-1, 833 cm-1, 1,470 cm-1 and 2,631 cm-1 in wave numbers. By comparing with infrared spectroscopic measurements of water, we are able to identify these transitions corroborating our hypothesis that the radiation originates from the transition of vibrational quantum energy levels of water molecules in aggregate. We have also repeated our previous study of the decay rate of tsunamis for a different tsunami. An estimate of the intensity of the tsunami radiation is made.

  7. When Extrasolar Planets Transit Their Parent Stars

    CERN Document Server

    Charbonneau, D; Burrows, A; Laughlin, G; Charbonneau, David; Brown, Timothy M.; Burrows, Adam; Laughlin, Greg

    2006-01-01

    When extrasolar planets are observed to transit their parent stars, we are granted unprecedented access to their physical properties. It is only for transiting planets that we are permitted direct estimates of the planetary masses and radii, which provide the fundamental constraints on models of their physical structure. In particular, precise determination of the radius may indicate the presence (or absence) of a core of solid material, which in turn would speak to the canonical formation model of gas accretion onto a core of ice and rock embedded in a protoplanetary disk. Furthermore, the radii of planets in close proximity to their stars are affected by tidal effects and the intense stellar radiation. As a result, some of these "hot Jupiters" are significantly larger than Jupiter in radius. Precision follow-up studies of such objects (notably with the space-based platforms of the Hubble and Spitzer Space Telescopes) have enabled direct observation of their transmission spectra and emitted radiation. These ...

  8. The Managerial Transition.

    Science.gov (United States)

    Kneeland, Steven J.

    1980-01-01

    Having identified the problem of managerial transition in a previous article (CE 510 277), the author outlines a strategy for change which includes performance appraisal, definition of the management structure, and counselling for the individual in transition. (SK)

  9. Radiation physics for medical physicists

    Energy Technology Data Exchange (ETDEWEB)

    Podgorsak, E.B. [McGill Univ. Health Centre, Montreal, QC (Canada). Dept. of Medical Physics

    2006-07-01

    This book summarizes the radiation physics knowledge that professionals working in medical physics need to master for efficient and safe dealings with ionizing radiation. It contains eight chapters, each chapter covering a specific group of subjects related to radiation physics and is intended as a textbook for a course in radiation physics in medical-physics graduate programs. However, the book may also be of interest to the large number of professionals, not only medical physicists, who in their daily occupations deal with various aspects of medical physics and find a need to improve their understanding of radiation physics. The main target audience for this book is graduate students studying for M.Sc. and Ph.D. degrees in medical physics, who have to possess the necessary physics and mathematics background knowledge to be able to follow and master the complete textbook. Medical residents, technology students and biomedical engineering students may find certain sections too challenging or esoteric, yet they will find many sections interesting and useful in their studies. Candidates preparing for professional certification exams in any of the medical physics subspecialties should find the material useful, and some of the material would also help candidates preparing for certification examinations in medical dosimetry or radiation-related medical specialties. Numerous textbooks are available covering the various subspecialties of medical physics but they generally make a transition from the elementary basic physics directly into the intricacies of the given medical physics subspecialty. The intent of this textbook is to provide the missing link between the elementary physics on the one hand and the physics of the subspecialties on the other hand. (orig.)

  10. Clinical and technological transition in breast cancer

    OpenAIRE

    Poortmans, Philip; Marsiglia, Hugo; de las Heras, Manuel; Algara, Manuel

    2013-01-01

    This article is a summary of the conference “Clinical and technological transition in breast cancer” that took place in the Congress of the Spanish Society of Radiation Oncology, placed in Vigo (Spain) on June 21, 2013. Hugo Marsiglia and Philip Poortmanns were the speakers, the first discussed about “Clinical and technological transition” and the second about “EORTC clinical trials and protocols”.

  11. Electromagnetic and Weak transitions in light nuclei

    Energy Technology Data Exchange (ETDEWEB)

    M. Viviani; L.E. Marcucci; A. Kievsky; S. Rosati; R. Schiavilla

    2002-09-01

    Recent advances in the study of the p -- d radiative and mu -- {sup 3}He weak capture processes by our group are presented and discussed. The trinucleon bound and scattering states have been obtained from variational calculations by expanding the corresponding wave functions in terms of correlated hyper-spherical harmonic functions. The electromagnetic and weak transition currents include one- and two-body operators. The accuracy achieved in these calculations allows for interesting comparisons with experimental data.

  12. Transitivity of Preferences

    Science.gov (United States)

    Regenwetter, Michel; Dana, Jason; Davis-Stober, Clintin P.

    2011-01-01

    Transitivity of preferences is a fundamental principle shared by most major contemporary rational, prescriptive, and descriptive models of decision making. To have transitive preferences, a person, group, or society that prefers choice option "x" to "y" and "y" to "z" must prefer "x" to "z". Any claim of empirical violations of transitivity by…

  13. Spacesuit Radiation Shield Design Methods

    Science.gov (United States)

    Wilson, John W.; Anderson, Brooke M.; Cucinotta, Francis A.; Ware, J.; Zeitlin, Cary J.

    2006-01-01

    Meeting radiation protection requirements during EVA is predominantly an operational issue with some potential considerations for temporary shelter. The issue of spacesuit shielding is mainly guided by the potential of accidental exposure when operational and temporary shelter considerations fail to maintain exposures within operational limits. In this case, very high exposure levels are possible which could result in observable health effects and even be life threatening. Under these assumptions, potential spacesuit radiation exposures have been studied using known historical solar particle events to gain insight on the usefulness of modification of spacesuit design in which the control of skin exposure is a critical design issue and reduction of blood forming organ exposure is desirable. Transition to a new spacesuit design including soft upper-torso and reconfigured life support hardware gives an opportunity to optimize the next generation spacesuit for reduced potential health effects during an accidental exposure.

  14. Radiation and Pregnancy

    Science.gov (United States)

    ... Home > Pregnancy > Is it safe? > Radiation and pregnancy Radiation and pregnancy E-mail to a friend Please ... can you protect yourself and your baby from radiation during pregnancy? Tell any health care provider you ...

  15. Breast radiation - discharge

    Science.gov (United States)

    Radiation - breast - discharge ... away around 4 to 6 weeks after the radiation treatment is over. You may notice changes in ... breast looks or feels (if you are getting radiation after a lumpectomy). These changes include: Soreness or ...

  16. Radiation related basic cancer research

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hoon; Yoo, Young Do; Hong, Seok Il [and others

    2000-04-01

    We studied the mechanism of radiation-induced apoptosis, the factors involved signaling, and the establishment of radiation-resistant cell lines in this study. During the TGF beta-stimulated epithelial mesenchymal transition(EMT), actin rearrangement occurred first and fibronectin matrix assembly followed. These two events were considered independent since cytochalasin-D did not inhibit TGF stimulated matrix assembly and fibronectin supplementation did not induce EMT. During EMT, alpha 5 beta 1 integrin and alpha v integrin have increased but MMP activation was not accompanied, which suggest that induction of extracellular matrix and activation of integrins may be main contributor for the EMT. Serum depriving induced apoptosis of HUVECs was prevented by vascular endothelial growth factor(VEGF) and PMA. The apoptosis prevention by VEGF and PMA were conformed by DNA fragmentation assay. The p53 expression level was down regulated by VEGF and PMA compared with serum deprived HUVECs. However, VEGF and PMA induces c-Myc expression level on these cells. We made the 5 radiation-resistant clones from breast, lung and cervical cancer cells. More than 70%, 100% and 50% increased resistance was detected in breast cancer cells, lung cancer cells, and cervical cells, respectively. We carried out differential display-PCR to clone the radiation-resistant genes. 9 out of 10 genes were analyzed their sequence.

  17. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Siegel, Robert

    2016-01-01

    Further expanding on the changes made to the fifth edition, Thermal Radiation Heat Transfer, 6th Edition continues to highlight the relevance of thermal radiative transfer and focus on concepts that develop the radiative transfer equation (RTE). The book explains the fundamentals of radiative transfer, introduces the energy and radiative transfer equations, covers a variety of approaches used to gauge radiative heat exchange between different surfaces and structures, and provides solution techniques for solving the RTE.

  18. Radiation controlling reversible window

    Energy Technology Data Exchange (ETDEWEB)

    Gell, H.A. Jr.

    1980-01-01

    A coated glass glazing system is presented including a transparent glass substrate having one surface coated with a radiation absorptive film which is overcoated with a radiation reflective film by a technique which renders the radiation reflective film radiation absorptive at the surface contracting the radiating absorptive film. The coated glass system is used as glazing for storm windows which are adapted to be reversible so that the radiation reflective surface may be exposed to the outside of the dwelling during the warm seasons to prevent excessive solar radiation from entering a dwelling and reversed during cold seasons to absorb solar radiation and utilize it to aid in keeping the dwelling interior warm.

  19. Transitive spaces of operators

    CERN Document Server

    Davidson, K R; Radjavi, H

    2007-01-01

    We investigate algebraic and topological transitivity and, more generally, k-transitivity for linear spaces of operators. In finite dimensions, we determine minimal dimensions of k-transitive spaces for every k, and find relations between the degree of transitivity of a product or tensor product on the one hand and those of the factors on the other. We present counterexamples to some natural conjectures. Some infinite dimensional analogues are discussed. A simple proof is given of Arveson's result on the weak-operator density of transitive spaces that are masa bimodules.

  20. Transition Theory – Sustainable Transition of Socio-Technical Systems

    DEFF Research Database (Denmark)

    Søndergård, Bent; Holm, Jesper; Stauning, Inger

    2015-01-01

    Theories of transition management, transition studies and social practise theory Applied to studies of hosuing and construction......Theories of transition management, transition studies and social practise theory Applied to studies of hosuing and construction...

  1. The radiation of ULTEM

    Energy Technology Data Exchange (ETDEWEB)

    Sheila, D.; Hill, D.J.; Whitaker, A.K. [The University of Queensland, Brisbane, QLD (Australia). Department of Chemistry, Polymer Material and Radiation Group

    1998-12-31

    Polyimide polymers and membranes have interesting mechanical, thermal and electrical properties, and useful for industrial applications. They are also known for their exceptional thermo-oxidative and chemical resistance. High performance linear aromatic polymers with skeletons composed primarily of aromatic units are expected to be the materials used in high energy radiation fields, such as space and fusion reactor environments. In this study the ESR technique was employed to study the radiation resistivity of ULTEM. Gamma irradiations were carried out at 77 K and the ambient temperature. The neutral and anionic free radicals produced at 52 Mrad, and 77 K were further thermally annealed to just above glass transition temperature. The annealing resulted in two decay regions, namely 130-230 K and above 250 K, corresponding to the decay of anion radicals and neutral radicals respectively. The sample was further irradiated for 20 Mrads at 77 K. Photobleaching with visible light at 610 nm and 510 nm were carried out to detrap the anionic radicals. It was observed that up to 71% of the radicals were detrapped by photobleaching. Further annealing up to 490 K, following the photobleaching, showed complete decay of the radicals. {sup 1}H and {sup 13}C NMR of the polymers irradiated at 100, 250 and 500 Mrad clearly showed the evidence of cross linking at 250 Mrad. New peaks were identified for {sup 1}H NMR at {delta} 1.60 a 7.04. GPC results of the irradiated polymer at 52, 100, and 250 Mrad showed increase in molecular weight after initial decline

  2. Radiation sources and diagnostics with ultrashort electron bunches

    Energy Technology Data Exchange (ETDEWEB)

    Catravas, P.; Esarey, E.; Leemans, W.P.

    2001-11-02

    The basic principles and design of radiation sources (transition radiation, Cerenkov radiation, radiation from periodic structures, etc.) and radiation-based diagnostics will be discussed, with emphasis on radiation from ultra-short electron bunches. Ultra-short electron bunches have the potential to produce high peak flux radiation sources that cover wavelength regimes where sources are currently not widely available (coherent THz/IR) as well as ultrashort X-ray pulses (3-100 fs). While radiation from the electron bunch contains the full signature of the electron beam and/or medium it has travelled through, the deconvolution of a single property of interest can be difficult due to a large number of contributing properties. The experimental implementation of novel solutions to this problem will be described for beams from 30 MeV to 30 GeV, including fluctuational interferometry, source imaging, phase matched cone angles and laser-based techniques, which utilize optical transition radiation, wiggler and Cerenkov radiation, and Thomson scattering. These novel diagnostic methods have the potential to resolve fs bunch durations, slice emittance on fs scales, etc. The advantages and novel features of these techniques will be discussed.

  3. Monte Carlo techniques in radiation therapy

    CERN Document Server

    Verhaegen, Frank

    2013-01-01

    Modern cancer treatment relies on Monte Carlo simulations to help radiotherapists and clinical physicists better understand and compute radiation dose from imaging devices as well as exploit four-dimensional imaging data. With Monte Carlo-based treatment planning tools now available from commercial vendors, a complete transition to Monte Carlo-based dose calculation methods in radiotherapy could likely take place in the next decade. Monte Carlo Techniques in Radiation Therapy explores the use of Monte Carlo methods for modeling various features of internal and external radiation sources, including light ion beams. The book-the first of its kind-addresses applications of the Monte Carlo particle transport simulation technique in radiation therapy, mainly focusing on external beam radiotherapy and brachytherapy. It presents the mathematical and technical aspects of the methods in particle transport simulations. The book also discusses the modeling of medical linacs and other irradiation devices; issues specific...

  4. Radiative and non-radiative processes in jet-cooled NCNO

    Science.gov (United States)

    Qian, C. X. W.; Reisler, H.; Wittig, C.

    1987-08-01

    Lifetimes of excited vibronic levels in NCNO are measured both by LIF and by monitoring excited state absorptions. Fluorescence lifetimes are longer than S 1 radiative lifetimes at all wavelengths between the band origin (11339 cm -1) and Do (17085 cm -1). In the language of radiationless transitions, the behavior below Do is characteristic of the "small or intermediate molecule lim

  5. Detection of Terahertz Radiation

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a system for detecting terahertz radiation, a camera device, and a method for detecting terahertz radiation.......The present invention relates to a system for detecting terahertz radiation, a camera device, and a method for detecting terahertz radiation....

  6. Gravitation radiation observations

    OpenAIRE

    Glass, E. N.

    2017-01-01

    The notion of gravitational radiation begins with electromagnetic radiation. In 1887 Heinrich Hertz, working in one room, generated and received electromagnetic radiation. Maxwell's equations describe the electromagnetic field. The quanta of electromagnetic radiation are spin 1 photons. They are fundamental to atomic physics and quantum electrodynamics.

  7. Measurement of 2 characteristics of metastable helium important for laser cooling: loss rates due to collisions in presence of quasi-resonant laser radiation and transition rates for 2 forbidden transitions: 2{sup 3}P{sub 1} {yields} 1{sup 1}S{sub 0} and 2{sup 3}P{sub 2} {yields} 1{sup 1}S{sub 0}; Mesure de deux caracteristiques de l'helium metastable importantes pour le refroidissement radiatif: taux de pertes par collisions en presence de lumiere quasi-resonante et taux de transition des raies interdites 2{sup 3}P{sub 1} {yields} 1{sup 1}S{sub 0} et 2{sup 3}P{sub 2} {yields} 1{sup 1}S{sub 0}

    Energy Technology Data Exchange (ETDEWEB)

    Poupard, J

    2000-11-15

    This thesis presents the study of 2 characteristics of metastable helium that are important for laser cooling. First, we measure two-body losses in a magneto-optical trap. The losses, enhanced by nearly resonant laser radiation, are mainly due to ionizing collisions. We measure the loss rate by observing the decay of the number of trapped atoms using either atomic fluorescence or ion production. We study the loss rate as a function of the trapping laser parameters. The second part of the thesis concerns experiments to measure the transition rates of the intercombination lines: 2{sup 3}P{sub 1} to 1{sup 1}S{sub 0} and 2{sup 3}P{sub 2} to 1{sup 1}S{sub 0}. The first of these rates is measured by exciting a small fraction of the atoms in a magneto-optical trap to the 2{sup 3}P{sub 1} state and observing the decrease in the trap lifetime. We then measure the ratio of the transition rates for 2{sup 3}P{sub 1} and 2{sup 3}P{sub 2} towards the 1{sup 1}S{sub 0} ground state by monitoring the flux of UV photons associated with the transition. (author)

  8. Transition wavelengths and unresolved transition array statistics of ions with Z = 72-89

    Energy Technology Data Exchange (ETDEWEB)

    Kilbane, D, E-mail: Deirdre.Kilbane@ucd.ie [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)

    2011-08-28

    Potential extreme ultraviolet and soft x-ray radiation sources have been identified, using the flexible atomic code (FAC), as emission peaks arising from the 4d-4f and 4p-4d transitions in Pd-like to Rb-like ions of hafnium through actinium. The effects of configuration interaction are investigated and for increasing nuclear charge, these strong emitters are seen to separate and move to shorter wavelengths. Each source is characterized using the unresolved transition array model. They are proposed to complement the currently used nitrogen and argon sources in the 'water window', and as possible successors to tin in next-generation lithography.

  9. Hf Transition Probabilities and Abundances

    CERN Document Server

    Lawler, J E; Labby, Z E; Sneden, C; Cowan, J J; Ivans, I I

    2006-01-01

    Radiative lifetimes from laser-induced fluorescence measurements, accurate to about +/- 5 percent, are reported for 41 odd-parity levels of Hf II. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 150 lines of Hf II. Approximately half of these new transition probabilities overlap with recent independent measurements using a similar approach. The two sets of measurements are found to be in good agreement for measurements in common. Our new laboratory data are applied to refine the hafnium photospheric solar abundance and to determine hafnium abundances in 10 metal-poor giant stars with enhanced r-process abundances. For the Sun we derive log epsilon (Hf) = 0.88 +/- 0.08 from four lines; the uncertainty is dominated by the weakness of the lines and their blending by other spectral features. Within the uncertainties of our analysis, the r-process-rich stars possess constant Hf/La and Hf/Eu abundance ratios, log epsilon (Hf...

  10. Gd Transition Probabilities and Abundances

    CERN Document Server

    Den Hartog, E A; Sneden, C; Cowan, J J

    2006-01-01

    Radiative lifetimes, accurate to +/- 5%, have been measured for 49 even-parity and 14 odd-parity levels of Gd II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 611 lines of Gd II. This work is the largest-scale laboratory study to date of Gd II transition probabilities and the first using a high performance Fourier transform spectrometer. This improved data set has been used to determine a new solar photospheric Gd abundance, log epsilon = 1.11 +/- 0.03. Revised Gd abundances have also been derived for the r-process-rich metal-poor giant stars CS 22892-052, BD+17 3248, and HD 115444. The resulting Gd/Eu abundance ratios are in very good agreement with the solar-system r-process ratio. We have employed the increasingly accurate stellar abundance determinations, resulting in large part from the more precise laboratory atomic data, to predict directly the Solar System r-process elemental...

  11. Predictability of Critical Transitions

    CERN Document Server

    Zhang, Xiaozhu; Hallerberg, Sarah

    2015-01-01

    Critical transitions in multistable systems have been discussed as models for a variety of phenomena ranging from the extinctions of species to socio-economic changes and climate transitions between ice-ages and warm-ages. From bifurcation theory we can expect certain critical transitions to be preceded by a decreased recovery from external perturbations. The consequences of this critical slowing down have been observed as an increase in variance and autocorrelation prior to the transition. However especially in the presence of noise it is not clear, whether these changes in observation variables are statistically relevant such that they could be used as indicators for critical transitions. In this contribution we investigate the predictability of critical transitions in conceptual models. We study the the quadratic integrate-and-fire model and the van der Pol model, under the influence of external noise. We focus especially on the statistical analysis of the success of predictions and the overall predictabil...

  12. Gravitationally induced quantum transitions

    Science.gov (United States)

    Landry, A.; Paranjape, M. B.

    2016-06-01

    In this paper, we calculate the probability for resonantly inducing transitions in quantum states due to time-dependent gravitational perturbations. Contrary to common wisdom, the probability of inducing transitions is not infinitesimally small. We consider a system of ultracold neutrons, which are organized according to the energy levels of the Schrödinger equation in the presence of the Earth's gravitational field. Transitions between energy levels are induced by an oscillating driving force of frequency ω . The driving force is created by oscillating a macroscopic mass in the neighborhood of the system of neutrons. The neutron lifetime is approximately 880 sec while the probability of transitions increases as t2. Hence, the optimal strategy is to drive the system for two lifetimes. The transition amplitude then is of the order of 1.06 ×10-5, and hence with a million ultracold neutrons, one should be able to observe transitions.

  13. Gravitationally induced quantum transitions

    CERN Document Server

    Landry, A

    2016-01-01

    In this letter, we calculate the probability for resonantly induced transitions in quantum states due to time dependent gravitational perturbations. Contrary to common wisdom, the probability of inducing transitions is not infinitesimally small. We consider a system of ultra cold neutrons (UCN), which are organized according to the energy levels of the Schr\\"odinger equation in the presence of the earth's gravitational field. Transitions between energy levels are induced by an oscillating driving force of frequency $\\omega$. The driving force is created by oscillating a macroscopic mass in the neighbourhood of the system of neutrons. The neutrons decay in 880 seconds while the probability of transitions increase as $t^2$. Hence the optimal strategy is to drive the system for 2 lifetimes. The transition amplitude then is of the order of $1.06\\times 10^{-5}$ hence with a million ultra cold neutrons, one should be able to observe transitions.

  14. Measuring stellar granulation during planet transits

    Science.gov (United States)

    Chiavassa, A.; Caldas, A.; Selsis, F.; Leconte, J.; Von Paris, P.; Bordé, P.; Magic, Z.; Collet, R.; Asplund, M.

    2017-01-01

    Context. Stellar activity and convection-related surface structures might cause bias in planet detection and characterization that use these transits. Surface convection simulations help to quantify the granulation signal. Aims: We used realistic three-dimensional (3D) radiative hydrodynamical (RHD) simulations from the Stagger grid and synthetic images computed with the radiative transfer code Optim3D to model the transits of three prototype planets: a hot Jupiter, a hot Neptune, and a terrestrial planet. Methods: We computed intensity maps from RHD simulations of the Sun and a K-dwarf star at different wavelength bands from optical to far-infrared that cover the range of several ground- and space-based telescopes which observe exoplanet transits. We modeled the transit using synthetic stellar-disk images obtained with a spherical-tile imaging method and emulated the temporal variation of the granulation intensity generating random images covering a granulation time-series of 13.3 h. We measured the contribution of the stellar granulation on the light curves during the planet transit. Results: We identified two types of granulation noise that act simultaneously during the planet transit: (i) the intrinsic change in the granulation pattern with timescale (e.g., 10 min for solar-type stars assumed in this work) is smaller than the usual planet transit ( hours as in our prototype cases); and (ii) the fact that the transiting planet occults isolated regions of the photosphere that differ in local surface brightness as a result of convective-related surface structures. First, we showed that our modeling approach returns granulation timescale fluctuations that are comparable with what has been observed for the Sun. Then, our statistical approach shows that the granulation pattern of solar and K-dwarf-type stars have a non-negligible effect of the light curve depth during the transit, and, consequentially on the determination of the planet transit parameters such as the

  15. Turning Forbidden Transitions into Dominant Transitions

    CERN Document Server

    Rivera, Nicholas; Soljacic, Marin

    2016-01-01

    Surface phonon polaritons are hybrid modes of photons and optical phonons that can propagate on the surface of a polar dielectric. In this work, we show that the precise combination of confinement and bandwidth offered by surface phonon polaritons allows for the ability to take forbidden transitions and turn them into the primary means by which an electron emits light. We show that high-order multipolar transitions and two-photon emission processes can be over an order of magnitude faster than competing dipole transitions, as opposed to being as much as eight to ten orders of magnitude slower in free space. Our results have direct implications for the design of fundamentally new types of emitters in the mid and far IR: ones which prefer to change their angular momentum by large amounts and also ones that prefer to emit a relatively broad spectrum of entangled photons - potentially allowing for new sources of both single and multiple photons.

  16. Wireless radiation sensor

    Science.gov (United States)

    Lamberti, Vincent E.; Howell, Jr, Layton N.; Mee, David K.; Kress, Reid L.

    2016-08-09

    Disclosed is a sensor for detecting radiation. The sensor includes a ferromagnetic metal and a radiation sensitive material coupled to the ferromagnetic metal. The radiation sensitive material is operable to change a tensile stress of the ferromagnetic metal upon exposure to radiation. The radiation is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the changes in the tensile stress.

  17. Phase-change radiative thermal diode

    CERN Document Server

    Ben-Abdallah, Philippe

    2013-01-01

    A thermal diode transports heat mainly in one preferential direction rather than in the opposite direction. This behavior is generally due to the non-linear dependence of certain physical properties with respect to the temperature. Here we introduce a radiative thermal diode which rectifies heat transport thanks to the phase transitions of materials. Rectification coefficients greater than 70% and up to 90% are shown, even for small temperature differences. This result could have important applications in the development of futur contactless thermal circuits or in the conception of radiative coatings for thermal management.

  18. Transit Benefit Program Data -

    Data.gov (United States)

    Department of Transportation — This data set contains information about any US government agency participating in the transit benefits program, funding agreements, individual participating Federal...

  19. Installation of one supermodule of the ALICE Transition Radiation Detector.

    CERN Multimedia

    Saba, A.

    2006-01-01

    In order to be installed in the correct position, the TRD supermodule is placed in a special rotating frame. The space to fit the module is very tight, so the insertion is monitored from outside but also from inside the space frame.

  20. Time expansion chambers of the ALICE Transition Radiation Detector (TRD)

    CERN Multimedia

    2003-01-01

    The TRD is segmented into 18 sectors in the azimuthal angle. Each sector consists of 6 layers in the radial direction and is composed of 5 stacks in the longitudinal direction. This amounts to 540 individual detector modules with a total active area of roughly 750 m2 and 1.2 million readout channels. The largest module is 159 cm long and 120 cm wide.

  1. Manipulation of Terahertz Radiation Using Vanadium Dioxide

    Institute of Scientific and Technical Information of China (English)

    Qi-Ye Wen

    2014-01-01

    Vanadium dioxide (VO2) is a phase transition material which undergoes a reversible metal-insulator transition (MIT) when triggered by thermal, photo, electrical, and even stress. The huge conduction change of VO2 renders it a promising material for terahertz (THz) manipulation. In this paper, some interesting works concerning the growth and characteristics of the VO2 film are selectively reviewed. A switching of THz radiation by photo-driven VO2 film is demonstrated. Experiments indicate an ultrafast optical switching to THz transmission within 8 picoseconds, and a switching ratio reaches to over 80%during a wide frequency range from 0.3 THz to 2.5 THz.

  2. Gravitational waves from cosmological first order phase transitions

    CERN Document Server

    Hindmarsh, Mark; Rummukainen, Kari; Weir, David

    2015-01-01

    First order phase transitions in the early Universe generate gravitational waves, which may be observable in future space-based gravitational wave observatiories, e.g. the European eLISA satellite constellation. The gravitational waves provide an unprecedented direct view of the Universe at the time of their creation. We study the generation of the gravitational waves during a first order phase transition using large-scale simulations of a model consisting of relativistic fluid and an order parameter field. We observe that the dominant source of gravitational waves is the sound generated by the transition, resulting in considerably stronger radiation than earlier calculations have indicated.

  3. Nuclear clocks based on resonant excitation of gamma-transitions

    CERN Document Server

    Peik, Ekkehard

    2015-01-01

    We review the ideas and concepts for a clock that is based on a radiative transition in the nucleus rather than in the electron shell. This type of clock offers advantages like an insensitivity against field-induced systematic frequency shifts and the opportunity to obtain high stability from interrogating many nuclei in the solid state. Experimental work concentrates on the low-energy (about 8 eV) isomeric transition in Th-229. We review the status of the experiments that aim at a direct optical observation of this transition and outline the plans for high-resolution laser spectroscopy experiments.

  4. Electronic transitions of fluorene, dibenzofuran, carbazole, and dibenzothiophene

    DEFF Research Database (Denmark)

    Nguyen, Duy Duc; Trunk, John; Nakhimovsky, Lina;

    2010-01-01

    A comparative study of the electronic transitions of fluorene and its hetero-analogues dibenzofuran, carbazole, and dibenzothiophene was performed in a wide energy range. Gas phase, crystal phase, and linear dichroism electronic transmittance spectra were measured with synchrotron radiation....... Prediction of electronic transitions to excited singlet states was performed by using time-dependent density functional theory TD-B3LYP/6-31+G(d,p). Based on the experimental and theoretical results, symmetry assignments of electronic transitions in the vacuum and near-UV region are suggested...

  5. Origins of evolutionary transitions

    Indian Academy of Sciences (India)

    Ellen Clarke

    2014-04-01

    An `evolutionary transition in individuality’ or `major transition’ is a transformation in the hierarchical level at which natural selection operates on a population. In this article I give an abstract (i.e. level-neutral and substrate-neutral) articulation of the transition process in order to precisely understand how such processes can happen, especially how they can get started.

  6. Matter in transition

    Science.gov (United States)

    Anderson, Lara B.; Gray, James; Raghuram, Nikhil; Taylor, Washington

    2016-04-01

    We explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, where a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU( N) require Weierstrass models that cannot be realized from the standard SU( N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.

  7. Transition Texture Synthesis

    Institute of Scientific and Technical Information of China (English)

    Yueh-Yi Lai; Wen-Kai Tai

    2008-01-01

    Synthesis of transition textures is essential for displaying visually acceptable appearances on a terrain. This investigation presents a modified method for synthesizing the transition texture to be tiled on a terrain. All transition pattern types are recognized for a number of input textures. The proposed modified patch-based sampling texture synthesis approach, using the extra feature map of the input source and target textures for patch matching, can synthesize any transition texture on a succession pattern by initializing the output texture using a portion of the source texture enclosed in a transition cut. The transition boundary is further enhanced to improve the visual effect by tracing out the integral texture elements. Either the Game of Life model or Wang tiles method are exploited to present a good-looking profile of successions on a terrain for tiling transition textures. Experimental results indicate that the proposed method requires few input textures, yet synthesizes numerous tileable transition textures, which are useful for obtaining a vivid appearance of a terrain.

  8. Classical electromagnetic radiation of the Dirac electron

    Science.gov (United States)

    Lanyi, G.

    1973-01-01

    A wave-function-dependent four-vector potential is added to the Dirac equation in order to achieve conservation of energy and momentum for a Dirac electron and its emitted electromagnetic field. The resultant equation contains solutions which describe transitions between different energy states of the electron. As a consequence it is possible to follow the space-time evolution of such a process. This evolution is shown in the case of the spontaneous emission of an electromagnetic field by an electron bound in a hydrogen-like atom. The intensity of the radiation and the spectral distribution are calculated for transitions between two eigenstates. The theory gives a self-consistent deterministic description of some simple radiation processes without using quantum electrodynamics or the correspondence principle.

  9. Radiation from structured-ring resonators

    CERN Document Server

    Maling, B; Craster, R V

    2016-01-01

    We investigate the scalar-wave resonances of systems composed of identical Neumann-type inclusions arranged periodically around a circular ring. Drawing on natural similarities with the undamped Rayleigh-Bloch waves supported by infinite linear arrays, we deduce asymptotically the exponentially small radiative damping in the limit where the ring radius is large relative to the periodicity. In our asymptotic approach, locally linear Rayleigh-Bloch waves that attenuate exponentially away from the ring are matched to a ring-scale WKB-type wave field. The latter provides a descriptive physical picture of how the mode energy is transferred via tunnelling to a circular evanescent-to-propagating transition region a finite distance away from the ring, from where radiative grazing rays emanate to the far field. Excluding the zeroth-order standing-wave modes, the position of the transition circle bifurcates with respect to clockwise and anti-clockwise contributions, resulting in striking spiral wavefronts.

  10. Coherent forward and backward diffraction radiation of relativistic electrons in a dielectric targets

    Science.gov (United States)

    Naumenko, G. A.; Shevelev, M. V.; Popov, Yu A.

    2016-08-01

    During the interaction of the relativistic electrons field with a dielectric target various types of electromagnetic radiation, such as Cerenkov radiation, diffraction radiation, transition radiation can be generated. In this report we present the results of experimental studies of the diffraction radiation generated by relativistic electrons in a dielectric target at the interface vacuum-insulator and insulator-conductor in the millimeter wavelength range. The experimental results show that the component of the diffraction radiation of relativistic electrons at the interface insulator-conductor, for any significant refractive index of insulator, is suppressed. The analysis of the results from different points of view was done.

  11. Plutonium radiation surrogate

    Science.gov (United States)

    Frank, Michael I.

    2010-02-02

    A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

  12. Giant modification of atomic transitions probabilities induced by magnetic field: forbidden transitions become predominant

    CERN Document Server

    Sargsyan, A; Hakhumyan, G; Papoyan, A; Mariotti, E; Sarkisyan, D

    2014-01-01

    Magnetic field-induced giant modification of probabilities for seven components of 6S1/2 (Fg=3) - 6P3/2 (Fe=5) transition of Cs D2 line forbidden by selection rules is observed experimentally for the first time. For the case of excitation with circularly-polarized laser radiation, the probability of Fg=3,mF=-3 - Fe=5,mF=-2 transition becomes the largest among 25 transitions of Fg=3 - Fe=2,3,4,5 group in a wide range of magnetic field 200 - 3200 G. Moreover, the modification is the largest among D2 lines of alkali metals. A half-wave-thick cell (length along the beam propagation axis L=426 nm) filled with Cs has been used in order to achieve sub-Doppler resolution which allows for separating the large number of atomic transitions that appear in the absorption spectrum when an external magnetic field is applied. For B > 3 kG the group of seven transitions Fg=3 - Fe=5 is completely resolved and is located at the high frequency wing of Fg=3 - Fe=2,3,4 transitions. The applied theoretical model very well describes...

  13. Radiation protection at synchrotron radiation facilities.

    Science.gov (United States)

    Liu, J C; Vylet, V

    2001-01-01

    A synchrotron radiation (SR) facility typically consists of an injector, a storage ring, and SR beamlines. The latter two features are unique to SR facilities, when compared to other types of accelerator facilities. The SR facilities have the characteristics of low injection beam power, but high stored beam power. The storage ring is generally above ground with people occupying the experimental floor around a normally thin concrete ring wall. This paper addresses the radiation issues, in particular the shielding design, associated with the storage ring and SR beamlines. Normal and abnormal beam losses for injection and stored beams, as well as typical storage ring operation, are described. Ring shielding design for photons and neutrons from beam losses in the ring is discussed. Radiation safety issues and shielding design for SR beamlines, considering gas bremsstrahlung and synchrotron radiation, are reviewed. Radiation source terms and the methodologies for shielding calculations are presented.

  14. Predictability of critical transitions

    Science.gov (United States)

    Zhang, Xiaozhu; Kuehn, Christian; Hallerberg, Sarah

    2015-11-01

    Critical transitions in multistable systems have been discussed as models for a variety of phenomena ranging from the extinctions of species to socioeconomic changes and climate transitions between ice ages and warm ages. From bifurcation theory we can expect certain critical transitions to be preceded by a decreased recovery from external perturbations. The consequences of this critical slowing down have been observed as an increase in variance and autocorrelation prior to the transition. However, especially in the presence of noise, it is not clear whether these changes in observation variables are statistically relevant such that they could be used as indicators for critical transitions. In this contribution we investigate the predictability of critical transitions in conceptual models. We study the quadratic integrate-and-fire model and the van der Pol model under the influence of external noise. We focus especially on the statistical analysis of the success of predictions and the overall predictability of the system. The performance of different indicator variables turns out to be dependent on the specific model under study and the conditions of accessing it. Furthermore, we study the influence of the magnitude of transitions on the predictive performance.

  15. Radiation therapy -- skin care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000735.htm Radiation therapy - skin care To use the sharing features ... this page, please enable JavaScript. When you have radiation treatment for cancer, you may have some changes ...

  16. Environmental Radiation Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Environmental Radiation Data (ERD) is an electronic and print journal compiled and distributed quarterly by the Office of Radiation and Indoor Air's National Air...

  17. Hendee's radiation therapy physics

    CERN Document Server

    Pawlicki, Todd; Starkschall, George

    2016-01-01

    The publication of this fourth edition, more than ten years on from the publication of Radiation Therapy Physics third edition, provides a comprehensive and valuable update to the educational offerings in this field. Led by a new team of highly esteemed authors, building on Dr Hendee’s tradition, Hendee’s Radiation Therapy Physics offers a succinctly written, fully modernised update. Radiation physics has undergone many changes in the past ten years: intensity-modulated radiation therapy (IMRT) has become a routine method of radiation treatment delivery, digital imaging has replaced film-screen imaging for localization and verification, image-guided radiation therapy (IGRT) is frequently used, in many centers proton therapy has become a viable mode of radiation therapy, new approaches have been introduced to radiation therapy quality assurance and safety that focus more on process analysis rather than specific performance testing, and the explosion in patient-and machine-related data has necessitated an ...

  18. Radiation processing in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Economic scale of radiation application in the field of industry, agriculture and medicine in Japan in 1997 was investigated to compare its economic impacts with that of nuclear energy industry. Total production value of radiation application accounted for 54% of nuclear industry including nuclear energy industry and radiation applications in three fields above. Industrial radiation applications were further divided into five groups, namely nondestructive test, RI instruments, radiation facilities, radiation processing and ion beam processing. More than 70% of the total production value was brought about by ion beam processing for use with IC and semiconductors. Future economic prospect of radiation processing of polymers, for example cross-linking, EB curing, graft polymerization and degradation, is reviewed. Particular attention was paid to radiation vulcanization of natural rubber latex and also to degradation of natural polymers. (S. Ohno)

  19. Cell Radiation Experiment System

    Science.gov (United States)

    Morrison, Dennis R.

    2010-01-01

    The cell radiation experiment system (CRES) is a perfused-cell culture apparatus, within which cells from humans or other animals can (1) be maintained in homeostasis while (2) being exposed to ionizing radiation during controlled intervals and (3) being monitored to determine the effects of radiation and the repair of radiation damage. The CRES can be used, for example, to determine effects of drug, radiation, and combined drug and radiation treatments on both normal and tumor cells. The CRES can also be used to analyze the effects of radiosensitive or radioprotectant drugs on cells subjected to radiation. The knowledge gained by use of the CRES is expected to contribute to the development of better cancer treatments and of better protection for astronauts, medical-equipment operators, and nuclear-power-plant workers, and others exposed frequently to ionizing radiation.

  20. Environmental Radiation Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Environmental Radiation Data (ERD) is an electronic and print journal compiled and distributed quarterly by the Office of Radiation and Indoor Air's National Air and...

  1. External radiation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  2. Radiation effects in semiconductors

    CERN Document Server

    2011-01-01

    There is a need to understand and combat potential radiation damage problems in semiconductor devices and circuits. Written by international experts, this book explains the effects of radiation on semiconductor devices, radiation detectors, and electronic devices and components. These contributors explore emerging applications, detector technologies, circuit design techniques, new materials, and innovative system approaches. The text focuses on how the technology is being used rather than the mathematical foundations behind it. It covers CMOS radiation-tolerant circuit implementations, CMOS pr

  3. Heart and radiation

    Directory of Open Access Journals (Sweden)

    Lauro Martins Júnior

    2011-12-01

    Full Text Available ABSTRATC The heart exposition to ionizing radiation may produce lesions in cardiac structures, acute (in most of cases benign and reversible, or months and even years later. There is a direct relationship of severity of lesions with radiation doses. The clinical picture receives a new denomination: radiation induced cardiopathy. The more frequent use of radiation in diagnosis and therapeutics increases the importance of their knowledge and especially their prevention.

  4. Synchrotron radiation facilities

    CERN Multimedia

    1972-01-01

    Particularly in the past few years, interest in using the synchrotron radiation emanating from high energy, circular electron machines has grown considerably. In our February issue we included an article on the synchrotron radiation facility at Frascati. This month we are spreading the net wider — saying something about the properties of the radiation, listing the centres where synchrotron radiation facilities exist, adding a brief description of three of them and mentioning areas of physics in which the facilities are used.

  5. Hybrid radiator cooling system

    Science.gov (United States)

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  6. Scintigraphic evaluation of oesophageal transit during radiotherapy to the mediastinum

    Directory of Open Access Journals (Sweden)

    Cuccurullo Vincenzo

    2008-11-01

    Full Text Available Abstract Background To quantitatively evaluate radiation-induced impaired oesophageal transit with oesophageal transit scintigraphy and to assess the relationships between acute oesophagitis symptoms and dysmotility. Methods Between January 1996 and November 1998, 11 patients affected by non-small-cell carcinoma of the lung not directly involving the oesophagus, requiring adjuvant external beam radiotherapy (RT to the mediastinum were enrolled. Oesophageal transit scans with liquid and semisolid bolus were performed at three pre-defined times: before (T0 and during radiation at 10 Gy (T1 and 30 Gy (T2. Two parameters were obtained for evaluation: 1 mean transit time (MTT; and 2 ratio between peak activity and residual activity at 40 seconds (ER-40s. Acute radiation toxicity was scored according to the joint EORTC-RTOG criteria. Mean values with standard deviation were calculated for all parameters. Analysis of variance (ANOVA tests and paired t-Tests for all values were performed. Results An increase in the ER-40s from T0 to T1 or T2 was seen in 9 of 11 patients (82%. The mean ER-40s value for all patients increased from 0.8306 (T0 to 0.8612 (T1 and 0.8658 (T2. These differences were statistically significant (p 0.05. Conclusion Using oesophageal scintigraphy we were able to detect early alterations of oesophageal transit during the third week of thoracic RT.

  7. Martensitic phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Petry, W.; Neuhaus, J. [Techn. Universitaet Muenchen, Physik Department E13, Munich (Germany)

    1996-11-01

    Many elements transform from a high temperature bcc phase to a more dense packed temperature phase. The great majority of these transitions are of 1st order, displacive and reconstructive. The lattice potentials which govern these martensitic transitions can be probed by inelastic neutron scattering, thereby answering fundamental questions like : Will the transition be announced by dynamical or static fluctuations? What are the trajectories for the displacements needed for the transformation? Does the vibrational entropy stabilize the high temperature phase? Are the unusual transport properties in these materials related to their ability to transform? (author) 17 figs., 1 tab., 46 refs.

  8. Transition nozzle combustion system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Wook; McMahan, Kevin Weston; Maldonado, Jaime Javier

    2016-11-29

    The present application provides a combustion system for use with a cooling flow. The combustion system may include a head end, an aft end, a transition nozzle extending from the head end to the aft end, and an impingement sleeve surrounding the transition nozzle. The impingement sleeve may define a first cavity in communication with the head end for a first portion of the cooling flow and a second cavity in communication with the aft end for a second portion of the cooling flow. The transition nozzle may include a number of cooling holes thereon in communication with the second portion of the cooling flow.

  9. Variational Transition State Theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, Donald G. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-09-29

    This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

  10. Radiative transfer effects in primordial hydrogen recombination

    CERN Document Server

    Ali-Haïmoud, Yacine; Hirata, Christopher M

    2010-01-01

    The calculation of a highly accurate cosmological recombination history has been the object of particular attention recently, as it constitutes the major theoretical uncertainty when predicting the angular power spectrum of Cosmic Microwave Background anisotropies. Lyman transitions, in particular the Lyman-alpha line, have long been recognized as one of the bottlenecks of recombination, due to their very low escape probabilities. The Sobolev approximation does not describe radiative transfer in the vicinity of Lyman lines to a sufficient degree of accuracy, and several corrections have already been computed in other works. In this paper, the impact of some previously ignored radiative transfer effects is calculated. First, the effect of Thomson scattering in the vicinity of the Lyman-alpha line is evaluated, using a full redistribution kernel incorporated into a radiative transfer code. The effect of feedback of distortions generated by the optically thick deuterium Lyman-alpha line blueward of the hydrogen ...

  11. Ultraviolet radiation and immunosuppression.

    LENUS (Irish Health Repository)

    Murphy, G M

    2009-11-01

    Ultraviolet (UV) radiation is a complete carcinogen. The effects of UV radiation are mediated via direct damage to cellular DNA in the skin and suppression of image surveillance mechanisms. In the context of organ transplantation, addiction of drugs which suppress the immune system add greatly to the carcinogenicity of UV radiation. This review considers the mechanisms of such effects.

  12. (Mis)Understanding Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, Stephen Bruce [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-10

    This set of slides discusses radiation and fears concerning it at a non-technical level. Included are some misconceptions and practical consequences resulting from these. The concept of radiation hormesis is explained. The author concludes that a number of significant societal benefits are being foregone because of overly cautious concerns about low-level radiation.

  13. Radiation bioengineering; Bioinzynieria radiacyjna

    Energy Technology Data Exchange (ETDEWEB)

    Rosiak, J.M. [Politechnika Lodzka, Lodz (Poland). Inst. Techniki Radiacynej

    1997-10-01

    Radiation processing for modification of different properties of materials being designed for medical use have been described. Especially the polymers as very often used for medical equipment production have been modified by radiation. The different medical applications of biomaterials based on radiation modified polymers have been presented. 13 refs.

  14. Biological implications of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bond, V.P.

    1977-01-01

    Some topics discussed are as follows: effects of diagnostic and therapeutic radiation on dividing cells, DNA, and blood cells; radiation sickness in relation to dose; early and late effects of radiation; effects of low dose irradiation; dose-effect curves; radioinduction of tumors in animals; and incidence of cancer in children following in utero exposure to diagnostic x rays. (HLW)

  15. Constraints on new physics from radiative $B$ decays

    CERN Document Server

    Paul, Ayan

    2016-01-01

    A new phase for the measurements of radiative decay modes in $b \\to s$ transitions has started with new measurements of exclusive modes by LHCb and with Belle-II showing distinctive promises in both inclusive and exclusive channels. After critically reviewing the hadronic uncertainties in exclusive radiative decays, we analyze the impact of recent measurements of the branching ratio and mass-eigenstate rate asymmetry in $B_s\\to\\phi\\gamma$ and of the angular distribution of $B\\to K^*e^+e^-$ at low $q^2$ on new physics in the $b\\to s\\gamma$ transition.

  16. Canonical Entropy and Phase Transition of Rotating Black Hole

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ren; WU Yue-Qin; ZHANG Li-Chun

    2008-01-01

    Recently, the Hawking radiation of a black hole has been studied using the tunnel effect method. The radiation spectrum of a black hole is derived. By discussing the correction to spectrum of the rotating black hole, we obtain the canonical entropy. The derived canonical entropy is equal to the sum of Bekenstein-Hawking entropy and correction term. The correction term near the critical point is different from the one near others. This difference plays an important role in studying the phase transition of the black hole. The black hole thermal capacity diverges at the critical point. However, the canonical entropy is not a complex number at this point. Thus we think that the phase transition created by this critical point is the second order phase transition. The discussed black hole is a five-dimensional Kerr-AdS black hole. We provide a basis for discussing thermodynamic properties of a higher-dimensional rotating black hole.

  17. Transition feeding of sows

    DEFF Research Database (Denmark)

    Theil, Peter Kappel

    2015-01-01

    becomes catabolic due to the high priority of milk production and to current feeding practices. Indeed, feed is changed from a gestation to a lactation diet for most sows and the feed supply typically goes from a restricted supply to an ad libitum allowance. In addition, transition sows are often exposed...... the first few days of lactation, and milk yield increases throughout the transition period and becomes the most important determinant of nutrient requirements. Thus, nutrient requirements of transition sows are affected by many intrinsic factors and these requirements change rapidly, yet, sow feeding...... practices do not acknowledge these changes. Development of new feeding strategies specifically adapted for the transition sow is likely of importance to match the rapid changes in nutrient requirements....

  18. Melting of Transition Metals

    Energy Technology Data Exchange (ETDEWEB)

    Ross, M; Japel, S; Boehler, R

    2005-04-11

    We review the transition melting studies carried out at Mainz, and describe a recently developed model used to explain that the relatively low melting slopes are due to the partially filled d-bands, and the persistence of the pressure induced s-d transition. The basic tenets of the model have now been reconfirmed by new measurements for Cu and Ni. The measurements show that Cu which has a filled 3d-band, has a melt slope that is about 2.5 greater than its neighbor Ni. In the case of Mo, the apparent discrepancy of DAC melting measurements with shock melting can be explained by accounting for the change in melt slope due to the bcc-cp transition observed in the shock studies. The Fe melt curve is revisited. The possible relevance of the Jahn-Teller effect and recently observed transition metal melts with Icosahedral Short-Range Order (ISRO) is discussed.

  19. Transitivity on Weierstrass points

    CERN Document Server

    Laing, Zoe

    2010-01-01

    We look for Riemann surfaces whose automorphism group acts transitively on the Weierstrass points. We concentrate on hyperelliptic surfaces, surfaces with PSL(2, q) as automorphism group, Platonic surfaces and Fermat curves.

  20. Transiting Exoplanets with JWST

    CERN Document Server

    Seager, S; Valenti, J A

    2008-01-01

    The era of exoplanet characterization is upon us. For a subset of exoplanets -- the transiting planets -- physical properties can be measured, including mass, radius, and atmosphere characteristics. Indeed, measuring the atmospheres of a further subset of transiting planets, the hot Jupiters, is now routine with the Spitzer Space Telescope. The James Webb Space Telescope (JWST) will continue Spitzer's legacy with its large mirror size and precise thermal stability. JWST is poised for the significant achievement of identifying habitable planets around bright M through G stars--rocky planets lacking extensive gas envelopes, with water vapor and signs of chemical disequilibrium in their atmospheres. Favorable transiting planet systems, are, however, anticipated to be rare and their atmosphere observations will require tens to hundreds of hours of JWST time per planet. We review what is known about the physical characteristics of transiting planets, summarize lessons learned from Spitzer high-contrast exoplanet m...

  1. Phase transitions modern applications

    CERN Document Server

    Gitterman, Moshe

    2014-01-01

    This book provides a comprehensive review of the theory of phase transitions and its modern applications, based on the five pillars of the modern theory of phase transitions i.e. the Ising model, mean field, scaling, renormalization group and universality. This expanded second edition includes, along with a description of vortices and high temperature superconductivity, a discussion of phase transitions in chemical reaction and moving systems. The book covers a close connection between phase transitions and small world phenomena as well as scale-free systems such as the stock market and the Internet. Readership: Scientists working in different fields of physics, chemistry, biology and economics as well as teaching material for undergraduate and graduate courses.

  2. Oligocyclopentadienyl transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    de Azevedo, Cristina G.; Vollhardt, K. Peter C.

    2002-01-18

    Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

  3. Superconductivity in transition metals.

    Science.gov (United States)

    Slocombe, Daniel R; Kuznetsov, Vladimir L; Grochala, Wojciech; Williams, Robert J P; Edwards, Peter P

    2015-03-13

    A qualitative account of the occurrence and magnitude of superconductivity in the transition metals is presented, with a primary emphasis on elements of the first row. Correlations of the important parameters of the Bardeen-Cooper-Schrieffer theory of superconductivity are highlighted with respect to the number of d-shell electrons per atom of the transition elements. The relation between the systematics of superconductivity in the transition metals and the periodic table high-lights the importance of short-range or chemical bonding on the remarkable natural phenomenon of superconductivity in the chemical elements. A relationship between superconductivity and lattice instability appears naturally as a balance and competition between localized covalent bonding and so-called broken covalency, which favours d-electron delocalization and superconductivity. In this manner, the systematics of superconductivity and various other physical properties of the transition elements are related and unified.

  4. Topics in radiation dosimetry radiation dosimetry

    CERN Document Server

    1972-01-01

    Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

  5. Purcell effect at the percolation transition

    Science.gov (United States)

    Szilard, D.; Kort-Kamp, W. J. M.; Rosa, F. S. S.; Pinheiro, F. A.; Farina, C.

    2016-10-01

    We investigate the spontaneous emission rate of a two-level quantum emitter next to a composite medium made of randomly distributed metallic inclusions embedded in a dielectric host matrix. In the near field, the Purcell factor can be enhanced by two orders of magnitude relative to the case of a homogeneous metallic medium and reaches its maximum precisely at the insulator-metal transition. By unveiling the role of the decay pathways in the emitter's lifetime, we demonstrate that, close to the percolation threshold, the radiation emission process is dictated by electromagnetic absorption in the heterogeneous medium. We show that our findings are robust against change in material properties and shape of inclusions and apply for different effective-medium theories as well as for a wide range of transition frequencies.

  6. Transitions in Energy Use

    OpenAIRE

    Grubler, A.

    2004-01-01

    Patterns of energy use have changed dramatically since the onset of the industrial revolution in terms of both energy quantities and energy quality. These changing patterns of energy use, where energy quantities and quality interact in numerous important ways, are referred to in this article as energy transitions and are described from a historical perspective as well as through future scenarios. Far from being completed, many of these transitions are continuing to unfold in industrial and de...

  7. The SAT phase transition

    Institute of Scientific and Technical Information of China (English)

    许可; 李未

    1999-01-01

    Phase transition is an important feature of SAT problem. For random k-SAT model, it is proved that as r(ratio of clauses to variables) increases, the structure of solutions will undergo a sudden change like satisfiability phase transition when r reaches a threshold point (r=rcr). This phenomenon shows that the satisfying truth assignments suddenly shift from being relatively different from each other to being very similar to each other.##属性不符

  8. The WFCAM Transit Survey

    Directory of Open Access Journals (Sweden)

    Hodgkin S.

    2011-02-01

    Full Text Available The WFCAM Transit Survey (WTS has been obtaining data on the United Kingdom Infrared Telescope since 2007. The WTS targets about 8,000 M dwarfs over several square degrees of sky, and aims to find low-mass eclipsing binaries and planets, down to the size of the Earth, transiting M dwarf stars with periods up to a few days.

  9. Stateless Transitive Signature Schemes

    Institute of Scientific and Technical Information of China (English)

    MA Chun-guang; CAI Man-chun; YANG Yi-xian

    2004-01-01

    A new practical method is introduced to transform the stateful transitive signature scheme to stateless one without the loss of security. According to the approach, two concrete stateless transitive signature schemes based on Factoring and RSA are presented respectively. Under the assumption of the hardness of factoring and one-more- RSA-inversion problem, both two schemes are secure under the adaptive chosen-message attacks in random oracle model.

  10. Atomic transition probabilities of Gd i

    Science.gov (United States)

    Lawler, J. E.; Bilty, K. A.; Den Hartog, E. A.

    2011-05-01

    Fourier transform spectra are used to determine emission branching fractions for 1290 lines of the first spectrum of gadolinium (Gd i). These branching fractions are converted to absolute atomic transition probabilities using previously reported radiative lifetimes from time-resolved laser-induced-fluorescence measurements (Den Hartog et al 2011 J. Phys. B: At. Mol. Opt. Phys. 44 055001). The wavelength range of the data set is from 300 to 1850 nm. A least squares technique for separating blends of the first and second spectra lines is also described and demonstrated in this work.

  11. Atomic transition probabilities of Er i

    Science.gov (United States)

    Lawler, J. E.; Wyart, J.-F.; Den Hartog, E. A.

    2010-12-01

    Atomic transition probabilities for 562 lines of the first spectrum of erbium (Er i) are reported. These data are from new branching fraction measurements on Fourier transform spectra normalized with previously reported radiative lifetimes from time-resolved laser-induced fluorescence measurements (Den Hartog et al 2010 J. Phys. B: At. Mol. Opt. Phys. 43 155004). The wavelength range of the data set is from 298 to 1981 nm. In this work we explore the utility of parametric fits based on the Cowan code in assessing branching fraction errors due to lines connecting to unobserved lower levels.

  12. Nanorod optical antennas for dipolar transitions

    CERN Document Server

    Taminiau, Tim H; van Hulst, Niek F

    2009-01-01

    Optical antennas link objects to light. Here, we analyze metal nanorod antennas as cavities with variable reflection coefficients to derive the interaction of dipolar transitions with radiation through the antenna modes. The presented analytical model accurately describes the complete emission process, and is summarized in a phase-matching equation. We show how antenna modes evolve as they become increasingly more bound, i.e. plasmonic. The results illustrate why efficient antennas should not be too plasmonic, and how subradiant even modes can evolve into weakly-interacting dark modes. Our description is valid for the interaction of nanorods with light in general, and is thus widely applicable.

  13. Monitoring of radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service.

  14. Matter in transition

    CERN Document Server

    Anderson, Lara B; Raghuram, Nikhil; Taylor, Washington

    2015-01-01

    We explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, where a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU(N) require Weierstrass models...

  15. Radiation curing of epoxies

    Science.gov (United States)

    Dickson, Lawrence W.; Singh, Ajit

    The literature on radiation polymerization of epoxy compounds has been reviewed to assess the potential use of radiation for curing these industrially important monomers. Chemical curing of epoxies may proceed by either cationic or anionic mechanisms depending on the nature of the curing agent, but most epoxies polymerize by cationic mechanisms under the influence of high-energy radiation. Radiation-induced cationic polymerization of epoxy compounds is inhibited by trace quantities of water because of proton transfer from the chain-propagating epoxy cation to water. Several different methods with potential for obtaining high molecular weight polymers by curing epoxies with high-energy radiation have been studied. Polymeric products with epoxy-like properties have been produced by radiation curing of epoxy oligomers with terminal acrylate groups and mixtures of epoxies with vinyl monomers. Both of these types of resin have good potential for industrial-scale curing by radiation treatment.

  16. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Mengüç, M Pinar

    2011-01-01

    Providing a comprehensive overview of the radiative behavior and properties of materials, the fifth edition of this classic textbook describes the physics of radiative heat transfer, development of relevant analysis methods, and associated mathematical and numerical techniques. Retaining the salient features and fundamental coverage that have made it popular, Thermal Radiation Heat Transfer, Fifth Edition has been carefully streamlined to omit superfluous material, yet enhanced to update information with extensive references. Includes four new chapters on Inverse Methods, Electromagnetic Theory, Scattering and Absorption by Particles, and Near-Field Radiative Transfer Keeping pace with significant developments, this book begins by addressing the radiative properties of blackbody and opaque materials, and how they are predicted using electromagnetic theory and obtained through measurements. It discusses radiative exchange in enclosures without any radiating medium between the surfaces-and where heat conduction...

  17. Biological improvement of radiation resistance

    Energy Technology Data Exchange (ETDEWEB)

    Chun, K. J.; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J

    2000-08-01

    To investigate the mechanisms of gene action related to the radiation resistance in microorganisms could be essentially helpful for the development of radiation protectants and hormeric effects of low dose radiation. This book described isolation of radiation-resistant microorganisms, induction of radiation-resistant and functionally improved mutants by gamma-ray radiation, cloning and analysis of the radiation resistance related genes and analysis of the expressed proteins of the radiation resistant related genes.

  18. Hawking Radiation and Classical Tunneling

    CERN Document Server

    Tracy, Eugene R

    2015-01-01

    Acoustic waves in fluids undergoing the transition from sub- to supersonic flow satisfy governing equations similar to those for light waves in the immediate vicinity of a black hole event horizon. This acoustic analogy has been used by Unruh and others as a conceptual model for `Hawking radiation.' Here we use variational methods, originally introduced by Brizard for the study of linearized MHD, and ray phase space methods, to analyze linearized acoustics in the presence of background flows. The variational formulation endows the evolution equations with natural Hermitian and symplectic structures that prove useful for later analysis. We derive a $2\\times 2$ normal form governing the wave evolution in the vicinity of the `event horizon.' This shows that the acoustic model can be reduced locally (in ray phase space) to a standard (scalar) tunneling process weakly coupled to a unidirectional non-dispersive wave (the `incoming wave'). Given the normal form, the Hawking `thermal spectrum' can be derived by invok...

  19. Spectral Brilliance of Channeling Radiation at the ASTA Photoinjector

    CERN Document Server

    Sen, Tanaji

    2014-01-01

    We study channeling radiation from electron beams with energies under 100 MeV. We introduce a phenomenological model of dechanneling, correct non-radiative transition rates from thermal scattering and discuss in detail the population dynamics in low order bound states. These are used to revisit the measured X-ray properties at the ELBE facility, extract parameters for dechanneling states and obtain satisfactory agreement with measured photon yields. The importance of rechanneling phenomena in thick crystals is emphasized. The model is then used to calculate the expected X-ray energies, linewidths and the brilliance for forthcoming channeling radiations experiments at Fermilab's ASTA photo-injector.

  20. Radiation processing of polyethylene

    Science.gov (United States)

    Barlow, A.; Biggs, J. W.; Meeks, L. A.

    This paper covers two areas (a) the use of high energy radiation for the synthesis and improvement of polymer properties and (b) the formulation of radiation curable compounds for automotive/appliance wire applications and high voltage insulation. The first part discusses the use of gamma radiation for the bulk polymerization of ethylene and the properties of the polymer produced. The use of low dose radiation to increase polymer molecular weight and modify polydispersity is also described together with its projected operational cost. An update is provided of the cost savings that can be realized when using radiation crosslinked heavy duty film, which expands its applications, compared with noncrosslinked materials. The second section of the paper considers the advantages and disadvantages of radiation vs. peroxide curing of wire and cable compounds. The formulation of a radiation curable, automotive/appliance wire compound is discussed together with the interactions between the various ingredients; i.e., base resin, antioxidants, flame retardant filler, coupling agents, processing aids and radiation to achieve the desired product. In addition, the general property requirements of a radiation curable polyethylene for high voltage insulation are discussed; these include crosslinking efficiency, thermal stability, wet tree resistance and satisfactory dielectric properties. Preliminary data generated in the development of a 230KV radiation crosslinked polyethylene insulation are included.

  1. Uzbekistan Radiation Portal Monnitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, J; Knapp, R; Loshak, A; Yuldashev, B; Petrenko, V

    2005-06-10

    The work proposed in this presentation builds on the foundation set by the DTRA funded demonstration project begun in 2000 and completed in December of 2003. This previous work consisted of two phases whose overall objective was to install portal radiation monitors at four select ports-of-entry in Uzbekistan (Tashkent International Airport, Gisht-Kuprik (Kazakhstan border), Alat (Turkmenistan border), and Termez (Afghanistan border)) in order to demonstrate their effectiveness in preventing the illicit trafficking of nuclear materials. The objectives also included developing and demonstrating capabilities in the design, installation, operation, training, and maintenance of a radiation portal monitoring system. The system and demonstration project has proved successful in many ways. An effective working relationship among the Uzbekistan Customs Services, Uzbekistan Border Guards, and Uzbekistan Institute of Nuclear Physics has been developed. There has been unprecedented openness with the sharing of portal monitor data with Lawrence Livermore National Laboratory. The system has proved to be effective, with detection of illicit trafficking, and, at Alat, an arrest of three persons illegally transporting radioactive materials into Turkmenistan. The demonstration project has made Uzbekistan a model nonproliferation state in Central Asia and, with an expanded program, places them in a position to seal a likely transit route for illicit nuclear materials. These results will be described. In addition, this work is currently being expanded to include additional ports-of-entry in Uzbekistan. The process for deciding on which additional ports-of-entry to equip will also be described.

  2. Examining hydrogen transitions.

    Energy Technology Data Exchange (ETDEWEB)

    Plotkin, S. E.; Energy Systems

    2007-03-01

    This report describes the results of an effort to identify key analytic issues associated with modeling a transition to hydrogen as a fuel for light duty vehicles, and using insights gained from this effort to suggest ways to improve ongoing modeling efforts. The study reported on here examined multiple hydrogen scenarios reported in the literature, identified modeling issues associated with those scenario analyses, and examined three DOE-sponsored hydrogen transition models in the context of those modeling issues. The three hydrogen transition models are HyTrans (contractor: Oak Ridge National Laboratory), MARKAL/DOE* (Brookhaven National Laboratory), and NEMS-H2 (OnLocation, Inc). The goals of these models are (1) to help DOE improve its R&D effort by identifying key technology and other roadblocks to a transition and testing its technical program goals to determine whether they are likely to lead to the market success of hydrogen technologies, (2) to evaluate alternative policies to promote a transition, and (3) to estimate the costs and benefits of alternative pathways to hydrogen development.

  3. Probing the π -π* transitions in conjugated compounds with an infrared femtosecond laser

    Science.gov (United States)

    Liu, Xi; Li, Pengcheng; Zhu, Xiaosong; Lan, Pengfei; Zhang, Qingbin; Lu, Peixiang

    2017-03-01

    We show that the processes of π -π* transitions imprint themselves on the high-harmonic spectra when conjugated molecules interact with intense femtosecond laser pulses. It is found that a noninteger order peak appears in the harmonic spectrum with the photon energy equaling the excitation energy of the π -π* excitation. Further studies prove that this radiation is caused by the π -π* transition. The transition signals are prominent and can be easily measured as the corresponding radiation intensities are comparable to those of integer order harmonics. Our results pave the way for the study of excited-state electron-ion dynamics using high-harmonic spectroscopy. In comparison to the traditional absorption spectroscopy method relying on the synchrotron radiation source, the present approach is easily accessible for the use of a tabletop laser-based source. Furthermore, our study also provides a potential tool to probe the π -π* transition processes in femtosecond resolution.

  4. Radiation physics, biophysics, and radiation biology

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  5. Parametric modal transition systems

    DEFF Research Database (Denmark)

    Beneš, Nikola; Křetínský, Jan; Larsen, Kim Guldstrand;

    2011-01-01

    Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects in the refin......Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects...... in the refinement process like exclusive, conditional and persistent choices. We introduce a new model called parametric modal transition systems (PMTS) together with a general modal refinement notion that overcome many of the limitations and we investigate the computational complexity of modal refinement checking....

  6. Citizens in sustainable transitions

    DEFF Research Database (Denmark)

    Hoffmann, Birgitte; Agger, Annika

    2013-01-01

    The paper explores how local public authorities can support and facilitate citizens’ participa-tion and learning in sustainable transition in urban neighbourhoods, by supporting local in-termediaries. The role of intermediaries can be performed by a variety of actors such as public housing...... associations; NGO´s, or semi public institutions. Our claim is that intermediary actors have the potential to facilitate new platforms for citizens’ participation in urban sustainable transition due to their particular role in between public authorities and civil society. The key question of the paper is how...... the intermediary actors facilitate citizens' participatory processes in sustainable urban transitions, and the paper explores the concept of institutional capacity building as a way to develop learning processes and new practises? The aim is to analyse approaches of creating platforms for involving citizens...

  7. Radiation hardness of indium oxide films in the Cooper-pair insulator state

    Directory of Open Access Journals (Sweden)

    Lazarević Đorđe R.

    2012-01-01

    Full Text Available This paper investigates possible radiation effects in the Cooper-pair insulator state of indium oxide films. Radiation effects are predicted on the basis of Monte Carlo simulations. Results of a combined theoretical and numerical analysis suggest that radiation-induced changes in the investigated films could significantly affect their current-voltage characteristics, and that a transition to a metallic state is possible, due to radiation-induced disruption of the fine-tuned granular structure. Dissociation of Cooper pairs, caused by both the incident radiation and the ions displaced within InOx films, can also destroy the conditions for this specific insulating state to subsist.

  8. Internal and external radiative widths in the combined R-matrix and potential model formalism

    CERN Document Server

    Mukhamedzhanov, A M; Bertulani, C A; Hao, T V Nhan

    2016-01-01

    Using the $R$-matrix approach we calculate the radiative width for a resonance decaying to a bound state through electric dipole, $E1$, transitions. The total radiative width is determined by the interference of the nuclear internal and external radiative width amplitudes. For a given channel radius the external radiative width amplitude is model independent and is determined by the asymptotic normalization coefficient (ANC) of the bound state to which the resonance decays. It also depends on the partial resonance width. To calculate the internal radiative width amplitude we show that a single particle potential model is appropriate. We compare our results with a few experimental data.

  9. Solar radiation models - review

    Directory of Open Access Journals (Sweden)

    M. Jamil Ahmad, G.N. Tiwari

    2010-05-01

    Full Text Available In the design and study of solar energy, information on solar radiation and its components at a given location is very essential. Solar radiation data are required by solar engineers, architects, agriculturists and hydrologists for many applications such as solar heating, cooking, drying and interior illumination of buildings. For this purpose, in the past, several empirical correlations have been developed in order to estimate the solar radiation around the world. The main objective of this study is to review the global solar radiation models available in the literature. There are several formulae which relate global radiation to other climatic parameters such as sunshine hours, relative humidity and maximum temperature. The most commonly used parameter for estimating global solar radiation is sunshine duration. Sunshine duration can be easily and reliably measured and data are widely available.

  10. China's urban transition.

    Science.gov (United States)

    Pannell, C

    1995-01-01

    This article describes recent changes in urban patterns in Shanghai-Nanjing, Beijing-Tianjin-Tangshan, Canton-Hong Kong, and Dalian-Shenyang. The urban patterns in these metropolitan areas are viewed as part of an urban transition that is responding to population growth, a structural shift in employment, relaxed rules on migration and household registration, and foreign investment and trade. It is argued that these metropolitan coastal areas will form the key growth centers and will lead China's economic development. Urban transition is defined as the shift from rural to urban and from agricultural employment to industrial, commercial, or service employment. China's large cities always dominated as important centers of politics and trade. The recent shift is from interior to coastal cities due to a new world view and a movement away from the isolationism of prior centuries. It is assumed that cities are formed to take advantage of economies of scale in production, consumption, and distribution and to conform to regional specialization. Governments can intervene in growth processes. China's development of cities reflects state controls and market forces. The size and scale of China's population influenced the development process, which resulted in differences in the shape and process of the urban transition. It was under Chinese communism that cities became more than a set of discrete regional urban systems. Reference is made to Oshima's model of change that is specific to monsoon countries. Oshima argues that monsoon agricultural conditions require a distinct strategy based on full employment in order to achieve industrial transition. Rice cultivation requires a large and disciplined labor force. The discussion focuses on other models as well, such as the McGee's model of the extended metropolis and its extension by Zhou Yixing to China. China's changes may not follow Skeldon's models of urbanization in developing countries, because of state control of migration

  11. Radiation | Smokefree.gov

    Science.gov (United States)

    About half of all cancer patients get radiation therapy. This treatment can damage healthy cells, which can cause uncomfortable side effects. Use this action deck to get information on common symptoms that affect people going through radiation and learn how to manage them. The side effects of radiation may depend on the part of your body being treated. If you don’t see the symptom cards that describe what you are going through, try building your own deck.

  12. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  13. RHOBOT: Radiation hardened robotics

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, P.C.; Posey, L.D. [Sandia National Labs., Albuquerque, NM (United States)

    1997-10-01

    A survey of robotic applications in radioactive environments has been conducted, and analysis of robotic system components and their response to the varying types and strengths of radiation has been completed. Two specific robotic systems for accident recovery and nuclear fuel movement have been analyzed in detail for radiation hardness. Finally, a general design approach for radiation-hardened robotics systems has been developed and is presented. This report completes this project which was funded under the Laboratory Directed Research and Development program.

  14. Transgenerational Radiation Epigenetics

    Science.gov (United States)

    2014-11-01

    showed altered expression in normal lung from F3 mice. Thus, traces of the effects of a single dose of radiation during development persist into...radiation showed a loss of global cytosine methylation in DNA from thymus , implicating profound epigenetic dysregulation (Tawa et al., 1998; Pogribny...for the carcinogenic and transgenerational effects of radiation. It is also anticipated that these epigenetic signatures will be developed as

  15. Electronic phase transitions

    CERN Document Server

    Kopaev, YuV

    1992-01-01

    Electronic Phase Transitions deals with topics, which are presently at the forefront of scientific research in modern solid-state theory. Anderson localization, which has fundamental implications in many areas of solid-state physics as well as spin glasses, with its influence on quite different research activities such as neural networks, are two examples that are reviewed in this book. The ab initio statistical mechanics of structural phase transitions is another prime example, where the interplay and connection of two unrelated disciplines of solid-state theory - first principle ele

  16. Spin transition in [Fe

    Science.gov (United States)

    Garcia, Y.; Ksenofontov, V.; Campbell, S. J.; Lord, J. S.; Boland, Y.; Gütlich, P.

    2004-12-01

    The reversible thermal spin transition which occurs in [Fe(phen)2(NCS)2] around T1/2 177 K has been investigated by muon spin relaxation (μSR) (10-280 K). The depolarisation curves are well described by two Lorentzian lines represent fast and slow components in the decay curves, with the initial asymmetry parameter of the fast component found to track the spin transition in [Fe(phen)2(NCS)2]. Comparison of zero-field and transverse field (20 Oe) μSR measurements shows that diamagnetic muonic species occur over the entire temperature range.

  17. Lost in Transit

    DEFF Research Database (Denmark)

    Lange, Ida Sofie Gøtzsche; Laursen, Lea Louise Holst; Lassen, Claus

    Thinking of Transit Places, the first sites that comes to mind will probably be airports, train stations and motorways. Such places are overall mono-functional with the embedded rationales of people's desires to move (themselves or goods) from one place to another. Often different service functions...... how a town primarily characterized by ferry transit is being challenged on its capacity to be a 'place' of meaning and social importance to its inhabitants. The paper raises the key question: Can a place become too well connected and this in such a manner that its identity and key character becomes...

  18. Pinocchio: Geppetto's transitional object

    Directory of Open Access Journals (Sweden)

    Gabriele Zeloni

    2015-01-01

    Full Text Available The literature has been considered by Freud and others after him, a form of unaware exploration of mind that can leads to discoveries similar to psychoanalysis’s discoveries. From this perspective, the author puts forward the following hypothesis: Pinocchio is a puppet who comes to life and is therefore, from a child's perception, a transitional object according to Winnicott. Consequently Geppetto is nothing more than the involuntary representation of any child interacting with the transitional object. The author explains the results of the analysis of the text in support of the hypothesis and reflects on the impact of The adventure of Pinocchio on the reader.

  19. Transition to the Cloud

    DEFF Research Database (Denmark)

    Hedman, Jonas; Xiao, Xiao

    2016-01-01

    companies operate. In this paper, we present a case study of an ERP vendor for SMB (small and mediumsize business) in making a transition towards a cloud-based business model. Through the theoretical lens of ecosystem, we are able to analyze the evolution of the vendor and its business network as a whole......The rising of cloud computing has dramatically changed the way software companies provide and distribute their IT product and related services over the last decades. Today, most software is bought offthe-shelf and distributed over the Internet. This transition is greatly influencing how software...

  20. 3D Gray Radiative Properties of a Radiation Hydrodynamic Model of a YSO Accretion Shock

    Science.gov (United States)

    Ibgui, L.; de Sá, L.; Stehlé, C.; Chièze, J.-P.; Orlando, S.; Hubeny, I.; Lanz, T.; Matsakos, T.; González, M.; Bonito, R.

    2014-09-01

    We present preliminary results of radiative properties of a 1D gray radiation hydrodynamic (RHD) model of an accretion shock on a young stellar object (YSO). This model takes into account the transition between the collisional equilibrium regime (local thermodynamic equilibrium, LTE), and the coronal equilibrium regime. Based on the 1D planar structure, we built a 3D cylindrical one. Most notably, the post-shock region obtained in our case is far less extended (by a factor of 10 000) than the typical one obtained with models that assume gray optically thin radiative losses. Moreover, we find that the column is optically thin in its longitudinal dimension, and in the transverse dimension, except over an extremely narrow region (≲ 700 m). Consequently, still under the gray assumption, the photons emitted by the hot slab can propagate through the column and escape freely in all directions, including towards the chromosphere. The radiation flux has therefore components that are perpendicular to the accretion column, which demonstrates that a multidimensional (2D or 3D) radiative model is necessary for such a cylindrical structure. This study needs to be taken forward and expanded, by improving the radiative treatment of the RHD model, through relaxation of both the gray and the LTE approximations for the calculation of opacities, in order to clarify the structure of the post-shock region, which is a major source of emission probed by observations.

  1. Potential theory of radiation

    Science.gov (United States)

    Chiu, Huei-Huang

    1989-01-01

    A theoretical method is being developed by which the structure of a radiation field can be predicted by a radiation potential theory, similar to a classical potential theory. The introduction of a scalar potential is justified on the grounds that the spectral intensity vector is irrotational. The vector is also solenoidal in the limits of a radiation field in complete radiative equilibrium or in a vacuum. This method provides an exact, elliptic type equation that will upgrade the accuracy and the efficiency of the current CFD programs required for the prediction of radiation and flow fields. A number of interesting results emerge from the present study. First, a steady state radiation field exhibits an optically modulated inverse square law distribution character. Secondly, the unsteady radiation field is structured with two conjugate scalar potentials. Each is governed by a Klein-Gordon equation with a frictional force and a restoring force. This steady potential field structure and the propagation of radiation potentials are consistent with the well known results of classical electromagnetic theory. The extension of the radiation potential theory for spray combustion and hypersonic flow is also recommended.

  2. Radiation hormesis in plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Lee, Byung Hun; Shin, In Chul; Lim, Young Taek

    2000-04-01

    This research was performed to investigate the effects of low dose {gamma}-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as subsequent high doses of radiation or Phytophthora blight of pepper could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant (POD) were accomplished in the plant irradiated with different dose of {gamma}-ray. (author)

  3. [Thyroid and radiation].

    Science.gov (United States)

    Yamashita, S; Namba, H; Nagataki, S

    1993-11-20

    The topic "Thyroid and Radiation" is both an old and a new area to be solved by human beings. The thyroid is an organ that is usually susceptible to exposure to ionizing radiation, both by virtue of its ability to concentrate radioiodine (internal radiation) and by routine medical examination: Chest X-ray, Dental X-ray, X-irradiation of cervical lymphnodes etc. (external radiation). Iodine-131 is widely used for the therapy of Graves' disease and thyroid cancers, of which the disadvantage is radiation-induced hypothyroidism but not complications of thyroid tumor. The thyroid gland is comparatively radioresistant, however, the data obtained from Hiroshima, Nagasaki and Marshall islands indicates a high incidence of external radiation-induced thyroid tumors as well as hypothyroidism. The different biological effects of internal and external radiation remains to be further clarified. Interestingly, recent reports demonstrate the increased number of thyroid cancer in children around Chernobyl in Belarus. In this review, we would like to introduce the effect of radiation on the thyroid gland at the molecular, cellular and tissue levels. Furthermore the clinical usefulness of iodine-131, including the safety-control for radiation exposure will be discussed.

  4. Optically pumped infrared stimulated radiation in pr3+:Y2SiO5

    Institute of Scientific and Technical Information of China (English)

    Yanliang Zhang(张衍亮); Zhenrong Sun(孙真荣); Yuqiong Li(李玉琼); Liang'en Ding(丁良恩); Zugeng Wang(王祖赓)

    2003-01-01

    The infrared stimulated radiation of 1D2 → 3F.2 and 1D2 → 3H6 transitions in Pr3+:Y2SiO5 (YSO) viapulsed laser pumping has been observed. The threshold energy, temperature dependence and divergenceangle for the stimulated radiation are also measured.

  5. Numerical study of acoustic streaming and radiation forces on micro particles

    DEFF Research Database (Denmark)

    Jensen, Mads Jakob Herring; Muller, Peter Barkholt; Barnkob, Rune;

    2012-01-01

    , and 2) Stokes drag from the induced acoustic streaming flow. Both effects are second order and require the solution of the full linearized Navier-Stokes equation in order to be captured correctly. The model shows the transition from streaming drag to radiation force dominated regimes. The transition...

  6. Families in Transition.

    Science.gov (United States)

    Britton, Patti O., Ed.; McGee, Michael, Ed.

    1987-01-01

    This issue of "Emphasis" deals with families in transition, providing some model programs for the new family and some historical perspectives on how families have developed over time. Articles include: (1) "Nostalgia on the Right" (Nancy Theriot); (2) "Heart to Heart" (Nancy Harrington-MacLennan); (3) "The Media Get the Message" (Janet Alyn); (4)…

  7. Administrative Theory in Transition.

    Science.gov (United States)

    Griffiths, Daniel E.

    This monograph analyzes transition in educational administrative theory. A brief introductory section describes the theoretical movement, the substance and repercussions of Thomas Greenfield's critique of educational administrative theory in 1974, and emerging qualitative approaches. Seven readings, all written by the volume's author, view…

  8. Photoinduced phase transitions

    CERN Document Server

    Nasu, K

    2004-01-01

    A new class of insulating solids was recently discovered. Whenirradiated by a few visible photons, these solids give rise to amacroscopic excited domain that has new structural and electronicorders quite different from the starting ground state. This occurrenceis called "photoinduced phase transition", and this multi-authoredbook reviews recent theoretical and experimental studies of this newphenomenon.

  9. eta ' transition form factors

    NARCIS (Netherlands)

    Amo Sanchez, del P.; Raven, H.G.; Snoek, H.; BaBar, Collaboration

    2011-01-01

    eta((')) transition form factors in the momentum-transfer range from 4 to 40 GeV(2). The analysis is based on 469 fb(-1) of integrated luminosity collected at PEP-II with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV.

  10. A Transiting Jupiter Analog

    CERN Document Server

    Kipping, David M; Henze, Chris; Teachey, Alex; Isaacson, Howard T; Petigura, Erik A; Marcy, Geoffrey W; Buchhave, Lars A; Chen, Jingjing; Bryson, Steve T; Sandford, Emily

    2016-01-01

    Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of $(0.91\\pm0.02)$ $R_{\\mathrm{Jup}}$, a low orbital eccentricity ($0.06_{-0.04}^{+0.10}$) and an equilibrium temperature of $(131\\pm3)$ K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric ...

  11. Variational transition state theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, D.G. [Univ. of Minnesota, Minneapolis (United States)

    1993-12-01

    This research program involves the development of variational transition state theory (VTST) and semiclassical tunneling methods for the calculation of gas-phase reaction rates and selected applications. The applications are selected for their fundamental interest and/or their relevance to combustion.

  12. Learning for Life Transitions

    Science.gov (United States)

    Varmecky, Jane Hyde

    2012-01-01

    Many adults return to formal learning situations to pursue lifelong learning goals because their lives are in transition from dealing with real-life problems such as divorce and re-marriage. The purpose of this study was to describe what couples learned that contributed to the success of their subsequent marriages and how they learned it. The…

  13. Outplacement as Transition Counseling.

    Science.gov (United States)

    Mirabile, Richard J.

    1985-01-01

    Describes outplacement counseling as a process that enables management to deal with the problem of the employee who must be released or the staff that must be reduced. Discusses the process of outplacement counseling, the stages of transition counseling, and techniques to be implemented. (BH)

  14. Families in Transition .

    Science.gov (United States)

    Bundy, Michael L., Ed.; Gumaer, James, Ed.

    1984-01-01

    Focuses on disrupted families and the role of the school counselor in helping children adjust. Describes characteristics of healthy families, and discusses the transition to the blended family, effects of divorce groups on children's classroom behavior, counseling children in stepfamilies, single-parent families, and parenting strengths of single…

  15. Transition and Financial Collapse

    NARCIS (Netherlands)

    Uhlig, H.F.H.V.S.

    1995-01-01

    One of the many problems facing the countries in transition from socialism to capitalism after the initial phase of privatization and restructuring is the lack of proven entrepreneurial talent in addition to a low initial level of capital. New entrepreneurs might find it hard to finance their start-

  16. Topological Transitions in Metamaterials

    CERN Document Server

    Krishnamoorthy, Harish N S; Narimanov, Evgenii; Kretzschmar, Ilona; Menon, Vinod M

    2011-01-01

    The ideas of mathematical topology play an important role in many aspects of modern physics - from phase transitions to field theory to nonlinear dynamics (1, 2). An important example of this is the Lifshitz transition (3), where the transformation of the Fermi surface of a metal from a closed to an open geometry (due to e.g. external pressure) leads to a dramatic effect on the electron magneto-transport (4). Here, we present the optical equivalent of the Lifshitz transition in strongly anisotropic metamaterials. When one of the components of the dielectric permittivity tensor of such a composite changes sign, the corresponding iso-frequency surface transforms from an ellipsoid to a hyperboloid. Since the photonic density of states can be related to the volume enclosed by the iso-frequency surface (5), such a topological transition in a metamaterial leads to a dramatic change in the photonic density of states, with a resulting effect on every single physical parameter related to the metamaterial - from thermo...

  17. Conceptions of Topological Transitivity

    CERN Document Server

    Akin, Ethan

    2011-01-01

    There are several different common definitions of a property in topological dynamics called "topological transitivity," and it is part of the folklore of dynamical systems that under reasonable hypotheses, they are equivalent. Various equivalences are proved in different places, but the full story is difficult to find. This note provides a complete description of the relationships among the different properties.

  18. Nursing Role Transition Preceptorship

    Science.gov (United States)

    Batory, Susan M.

    2014-01-01

    The preceptorship clinical experience in a practical nursing (PN) program at a Midwestern community college is considered crucial to the PN students' transition from novice nurse to professional nurse. However, no research has been available to determine whether the preceptorship clinical accomplishes its purpose. A case study was conducted to…

  19. Blackbody radiation shift in 87Rb frequency standard

    CERN Document Server

    Safronova, M S; Safronova, U I

    2010-01-01

    The operation of atomic clocks is generally carried out at room temperature, whereas the definition of the second refers to the clock transition in an atom at absolute zero. This implies that the clock transition frequency should be corrected in practice for the effect of finite temperature of which the leading contributor is the blackbody radiation (BBR) shift. Experimental measurements of the BBR shifts are difficult. In this work, we have calculated the blackbody radiation shift of the ground-state hyperfine microwave transition in 87Rb using the relativistic all-order method and carried out detailed evaluation of the accuracy of our final value. Particular care is taken to accurately account for the contributions from highly-excited states. Our predicted value for the Stark coefficient, k_S=-1.240(4)\\times 10^{-10}\\text{Hz/(V/m)}^{2} is three times more accurate than the previous calculation [1].

  20. Blackbody radiation shift in ^87Rb frequency standard

    Science.gov (United States)

    Safronova, Marianna; Safronova, U. I.

    2010-03-01

    The operation of atomic clocks is generally carried out at room temperature, whereas the definition of the second refers to the clock transition in an atom at absolute zero. This implies that the clock transition frequency should be corrected in practice for the effect of finite temperature of which the leading contributor is the blackbody radiation (BBR) shift. Experimental measurements of the BBR shifts are difficult. In this work, we have calculated the blackbody radiation shift of the ground-state hyperfine microwave transition in ^87Rb using the relativistic all-order method and evaluated the accuracy of our final value. Particular care is taken to accurately account for the contributions from highly-excited states. Various Rb atomic properties, including E1, E2, and E3 ground state polarizabilities, np and nd E1 polarizabilities, and hyperfine constants are also calculated. The results are compared with experiment and other theory where available.