WorldWideScience

Sample records for attaining ultra-high energies

  1. Ultra High Energy Nuclei Propagation

    CERN Document Server

    Aloisio, Roberto

    2008-01-01

    We discuss the problem of ultra high energy nuclei propagation in astrophysical backgrounds. We present a new analytical computation scheme based on the hypothesis of continuos energy losses in a kinetic formulation of the particles propagation. This scheme enables the computation of the fluxes of ultra high energy nuclei as well as the fluxes of secondaries (nuclei and nucleons) produced by the process of photo-disintegration suffered by nuclei.

  2. Detecting ultra high energy neutrinos with LOFAR

    NARCIS (Netherlands)

    Mevius, M.; Buitink, S.; Falcke, H.; Horandel, J.; James, C. W.; McFadden, R.; Scholten, O.; Singh, K.; Stappers, B.; ter Veen, S.

    2012-01-01

    The NuMoon project aims to detect signals of Ultra High Energy (UHE) Cosmic Rays with radio telescopes on Earth using the Lunar Cherenkov technique at low frequencies (similar to 150 MHz). The advantage of using low frequencies is the much larger effective detecting volume, with as trade-off the cut

  3. Cosmic absorption of ultra high energy particles

    Science.gov (United States)

    Ruffini, R.; Vereshchagin, G. V.; Xue, S.-S.

    2016-02-01

    This paper summarizes the limits on propagation of ultra high energy particles in the Universe, set up by their interactions with cosmic background of photons and neutrinos. By taking into account cosmic evolution of these backgrounds and considering appropriate interactions we derive the mean free path for ultra high energy photons, protons and neutrinos. For photons the relevant processes are the Breit-Wheeler process as well as the double pair production process. For protons the relevant reactions are the photopion production and the Bethe-Heitler process. We discuss the interplay between the energy loss length and mean free path for the Bethe-Heitler process. Neutrino opacity is determined by its scattering off the cosmic background neutrino. We compute for the first time the high energy neutrino horizon as a function of its energy.

  4. Ultra High Energy Cosmic Rays: Strangelets?

    Institute of Scientific and Technical Information of China (English)

    徐仁新; 吴飞

    2003-01-01

    The conjecture that ultra-high-energy cosmic rays (UHECRs) are actually strangelets is discussed. Besides the reason that strangelets can do as cosmic rays beyond the Greisen-Zatsepin-Kuzmin-cutoff, another argument to support the conjecture is addressed by the study of formation of Te V-scale microscopic black holes when UHECRs bombarding bare strange stars. It is proposed that the exotic quark surface of a bare strange star could be an effective astro-laboratory in the investigations of the extra dimensions and of the detection of ultra-high-energy neutrino fluxes. The flux of neutrinos (and other point-like particles) with energy larger than 2.3 × 1020 eV could be expected to be smaller than 10-26 cm-2 s-1 if there are two extra spatial dimensions.

  5. Ultra-High-Energy Cosmic Rays

    CERN Document Server

    Dova, M T

    2015-01-01

    The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 10 17 eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a written version of a series of lectures devoted to UHECR at the 2013 CERN-Latin-American School of High-Energy Physics. We present anintroduction to acceleration mechanisms of charged particles to the highest energies in astrophysical objects, their propagation from the sources to Earth, and the experimental techniques for their detection. We also discuss some of the relevant observational results from Telescope Array and Pierre Auger Observatory. These experiments deal with particle interactions at energies orders of magnitude higher than achieved in terrestrial accelerators.

  6. Tau Air-Showers Signature of Ultra High Energy Neutrinos

    CERN Document Server

    Fargion, D

    2001-01-01

    The discover of Ultra High Energy Neutrino of astrophysical nature may be already reached. Indeed upward and horizontal tau Air-showers emerging from the Earth crust or mountain chains offer the best and most powerful signal of Ultra High Energy UHE neutrinos nu_tau}, bar\

  7. The Telescope Array Ultra High Energy Cosmic Ray Obsrevatory

    Science.gov (United States)

    Matthews, John

    2016-07-01

    The Telescope Array measures the properties of ultra high energy cosmic ray induced extensive air showers. We do this using a variety of techniques including an array of scintillator detectors to sample the footprint of the air shower when it reaches the Earth's surface and telescopes to measure the fluorescence and Cerenkov light of the air shower. From this we determine the energy spectrum and chemical composition of the primary particles. We also search for sources of cosmic rays and anisotropy. We have found evidence of a possible source of ultra high energy cosmic rays in the northern sky. The experiment and its most recent measurements will be discussed.

  8. Ultra high energy cosmic rays: the highest energy frontier

    CERN Document Server

    Neto, João R T de Mello

    2015-01-01

    Ultra-high energy cosmic rays (UHECRs) are the highest energy messengers of the present universe, with energies up to $10^{20}$ eV. Studies of astrophysical particles (nuclei, electrons, neutrinos and photons) at their highest observed energies have implications for fundamental physics as well as astrophysics. The primary particles interact in the atmosphere and generate extensive air showers. Analysis of those showers enables one not only to estimate the energy, direction and most probable mass of the primary cosmic particles, but also to obtain information about the properties of their hadronic interactions at an energy more than one order of magnitude above that accessible with the current highest energy human-made accelerator. In this contribution we will review the state-of-the-art in UHECRs detection. We will present the leading experiments Pierre Auger Observatory and Telescope Array and discuss the cosmic ray energy spectrum, searches for directional anisotropy, studies of mass composition, the determ...

  9. On Anisotropy of Ultra-High Energy Cosmic-Rays

    CERN Document Server

    Kashti, Tamar

    2009-01-01

    We briefly summarize our study on anisotropy of Ultra-High Energy Cosmic-Rays (UHECRs), in which we define a statistics that measures the correlation between UHECRs and Large Scale Structure (LSS). We also comment here on recently published paper by Koers and Tinyakov that compared our statistics to improved KS statistics.

  10. Determining neutrino absorption spectra at ultra-high energies

    NARCIS (Netherlands)

    Scholten, O.; van Vliet, A. R.

    2008-01-01

    A very efficient method for measuring the flux of ultra-high energy ( UHE) neutrinos is through the detection of radio waves which are emitted by the particle shower in the lunar regolith. The highest acceptance is reached for radio waves in the frequency band of 100 - 200 MHz which can be measured

  11. Ultra high energy cosmic rays: the highest energy frontier

    Science.gov (United States)

    de Mello Neto, João R. T.

    2016-04-01

    Ultra-high energy cosmic rays (UHECRs) are the highest energy messengers of the present universe, with energies up to 1020 eV. Studies of astrophysical particles (nuclei, electrons, neutrinos and photons) at their highest observed energies have implications for fundamental physics as well as astrophysics. The primary particles interact in the atmosphere and generate extensive air showers. Analysis of those showers enables one not only to estimate the energy, direction and most probable mass of the primary cosmic particles, but also to obtain information about the properties of their hadronic interactions at an energy more than one order of magnitude above that accessible with the current highest energy human-made accelerator. In this contribution we will review the state-of-the-art in UHECRs detection. We will present the leading experiments Pierre Auger Observatory and Telescope Array and discuss the cosmic ray energy spectrum, searches for directional anisotropy, studies of mass composition, the determination of the number of shower muons (which is sensitive to the shower hadronic interactions) and the proton-air cross section.

  12. Elastic diffractive scattering of nucleons at ultra-high energies

    Energy Technology Data Exchange (ETDEWEB)

    Godizov, A.A., E-mail: anton.godizov@gmail.com

    2014-07-30

    A simple Regge-eikonal model with the eikonal represented as a single-reggeon-exchange term is applied to description of the nucleon–nucleon elastic diffractive scattering at ultra-high energies. The range of validity of the proposed approximation is discussed. The model predictions for the proton–proton cross-sections at the collision energy 14 TeV are given.

  13. Ultra High Energy Comic Rays in the Cosmic Microwave Background

    CERN Document Server

    Hwang, W-Y Pauchy

    2011-01-01

    We consider the propagation of ultra high energy cosmic rays (UHECR), for energies greater than E > 10^{14} eV but less than E < 10^{26} eV, in the cosmic medium of the Cosmic Microwave Background (CMB). We find that the CMB plays a pivot role in this energy range. As example, the observed "knee(s)" and the "ankle" could be understood in reasonable terms. What we may observe at energy near 10^{25} eV (W^\\pm bursts or Z^0 bursts) is also briefly discussed.

  14. Searching for ultra-high energy cosmic rays with smartphones

    Science.gov (United States)

    Whiteson, Daniel; Mulhearn, Michael; Shimmin, Chase; Cranmer, Kyle; Brodie, Kyle; Burns, Dustin

    2016-06-01

    We propose a novel approach for observing cosmic rays at ultra-high energy (>1018 eV) by repurposing the existing network of smartphones as a ground detector array. Extensive air showers generated by cosmic rays produce muons and high-energy photons, which can be detected by the CMOS sensors of smartphone cameras. The small size and low efficiency of each sensor is compensated by the large number of active phones. We show that if user adoption targets are met, such a network will have significant observing power at the highest energies.

  15. The Lamb Shift and Ultra High Energy Cosmic Rays

    CERN Document Server

    Xue, S S

    2002-01-01

    On the analogy with the Lamb shift, we study the vacuum effects that a proton interacts with virtual particles when it travels through the vacuum. We find that a moving proton is accelerated by gaining the zero-point energy from the vacuum (~10^{-5} eV/cm). Such an effect possibly accounts for the mysterious origin and spectrum of ultra high-energy cosmic ray events above 10^{20}eV, and explains the puzzle why the GZK cutoff is absent. The candidates of these events could be protons from early Universe.

  16. Ultra High Energy Electrons Powered by Pulsar Rotation

    CERN Document Server

    Mahajan, Swadesh; Osmanov, Zaza; Chkheidze, Nino

    2013-01-01

    A new mechanism of particle acceleration to ultra high energies, driven by the rotational slow down of a pulsar (Crab pulsar, for example), is explored. The rotation, through the time dependent centrifugal force, can very efficiently excite unstable Langmuir waves in the e-p plasma of the star magnetosphere via a parametric process. These waves, then, Landau damp on electrons accelerating them in the process. The net transfer of energy is optimal when the wave growth and the Landau damping times are comparable and are both very short compared to the star rotation time. We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar. This highly efficient route for energy transfer allows the electrons in the primary beam to be catapulted to multiple TeV ($\\sim 100$ TeV) and even PeV energy domain. It is expected that the proposed mechanism may, partially, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

  17. Ultra High Energy Density Cathodes with Carbon Nanotubes

    Science.gov (United States)

    2013-12-10

    34Enhanced Capacity and Rate Capability of Carbon Nanotube Based Anodes with Titanium Contacts for Lithium Ion Batteries," ACS Nano, vol. 4, pp. 6121- 6131...2010/10/26 2010. [2] S. L. Chou, et al., "Silicon/Single-Walled Carbon Nanotube Composite Paper as a Flexible Anode Material for Lithium Ion...AFRL-RV-PS- AFRL-RV-PS- TR-2013-0170 TR-2013-0170 ULTRA HIGH ENERGY DENSITY CATHODES WITH CARBON NANOTUBES Brian J. Landi, et al. Rochester

  18. Ultra High Energy Neutrino Signature in Top-Down Scenario

    CERN Document Server

    Aloisio, R

    2006-01-01

    Neutrinos are the best candidates to test the extreme Universe and ideas beyond the Standard Model of particle Physics. Once produced, neutrinos do not suffer any kind of attenuation by intervening radiation fields like the Cosmic Microwave Background and are not affected by magnetic fields. In this sense neutrinos are useful messengers from the far and young Universe. In the present paper we will discuss a particular class of sources of Ultra High Energy Cosmic Rays introduced to explain the possible excess of events with energy larger than the Graisen-Zatsepin-Kuzmin cut-off. These sources, collectively called top-down, share a common feature: UHE particles are produced in the decay or annihilation of superheavy, exotic, particles. As we will review in the present paper, the largest fraction of Ultra High Energy particles produced in the top-down scenario are neutrinos. The study of these radiation offers us a unique opportunity to test the exotic mechanisms of the top-down scenario.

  19. Ultra High Energy Cosmic Rays from Compact Sources

    CERN Document Server

    Fodor, Z

    2001-01-01

    The clustering of ultra high energy (above 10^20 eV) cosmic rays (UHECR) suggests that they might be emitted by compact sources. Statistical analysis of Dubovsky et al. (astro-ph/0001317) estimated the source density. We extend their analysis to give also the confidence intervals for the number of sources using a.) no assumptions on the relationship between clustered and unclustered events; b.) nontrivial distributions for the source intensities and energies; c.) the energy dependence of the propagation. We determine the probability that a proton created at a distance r with energy E arrives at earth above a threshold E_c. The observed 14 UHECR events above 10^20 eV with one doublet gives for the source densities 6.43_-6.05^+136*10^-3 Mpc^-3 (on the 68% confidence level). We present detailed results for future experiments with larger UHECRs statistics.

  20. Active Galactic Nuclei: Sources for ultra high energy cosmic rays?

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, Peter L. [MPI for Radioastronomy, Bonn (Germany); Dept. of Phys. and Astron., Univ. of Bonn (Germany); Dept. of Phys. and Astr., Univ. of Alabama, Tuscaloosa, AL (United States); Dept. of Phys., Univ. of Alabama at Huntsville, AL (United States); Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Becker, Julia K. [Institution foer Fysik, Goeteborgs Univ. (Sweden); Dept. of Phys., Univ. Dortmund, Dortmund (Germany); Caramete, Laurentiu [MPI for Radioastronomy, Bonn (Germany); Institute for Space Studies, Bucharest (Romania); Curutiu, Alex [MPI for Radioastronomy, Bonn (Germany); Engel, Ralph [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Falcke, Heino [Dept. of Astrophys., IMAP, Radboud Univ., Nijmegen (Netherlands); ASTRON, Dwingeloo (Netherlands); Gergely, Laszlo A. [Dept. Appl. Sci., London South Bank University (United Kingdom); Dept. of Theoret. and Exp. Phys., Univ. of Szeged, Szeged (Hungary); Isar, P. Gina [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Institute for Space Studies, Bucharest (Romania); Maris, Ioana C. [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Meli, Athina [Physik. Inst. Univ. Erlangen-Nuernberg (Germany); Kampert, Karl-Heinz [Phys. Dept., Univ. Wuppertal (Germany); Stanev, Todor [Bartol Research Inst., Univ. of Delaware, Newark, DE (United States); Tascau, Oana [Phys. Dept., Univ. Wuppertal (Germany); Zier, Christian [MPI for Radioastronomy, Bonn (Germany); Raman Res. Inst., Bangalore (India)

    2009-05-15

    The origin of ultra high energy cosmic rays promises to lead us to a deeper understanding of the structure of matter. This is possible through the study of particle collisions at center-of-mass energies in interactions far larger than anything possible with the Large Hadron Collider, albeit at the substantial cost of no control over the sources and interaction sites. For the extreme energies we have to identify and understand the sources first, before trying to use them as physics laboratories. Here we describe the current stage of this exploration. The most promising contenders as sources are radio galaxies and gamma ray bursts. The sky distribution of observed events yields a hint favoring radio galaxies. Key in this quest are the intergalactic and galactic magnetic fields, whose strength and structure are not yet fully understood. Current data and statistics do not yet allow a final judgement. We outline how we may progress in the near future.

  1. Extragalactic Propagation of Ultra-High Energy Cosmic Rays

    CERN Document Server

    Kuempel, Daniel

    2014-01-01

    More than 100 years after the discovery of cosmic rays and various experimental efforts, the origin of ultra-high energies (E > 100 PeV) remains unclear. The understanding of production and propagation effects of these highest energetic particles in the universe is one of the most intense research fields of high-energy astrophysics. With the advent of advanced simulation engines developed during the last couple of years, and the increase of experimental data, we are now in a unique position to model source and propagation parameters in an unprecedented precision and compare it to measured data from large scale observatories. In this paper we revisit the most important propagation effects of cosmic rays through photon backgrounds and magnetic fields and introduce recent developments of propagation codes. Finally, by comparing the results to experimental data, possible implications on astrophysical parameters are given.

  2. Projects for ultra-high-energy circular colliders at CERN

    Science.gov (United States)

    Bogomyagkov, A. V.; Koop, I. A.; Levichev, E. B.; Piminov, P. A.; Sinyatkin, S. V.; Shatilov, D. N.; Benedict, M.; Oide, K.; Zimmermann, F.

    2016-12-01

    Within the Future Circular Collider (FCC) design study launched at CERN in 2014, it is envisaged to construct hadron (FCC-hh) and lepton (FCC-ee) ultra-high-energy machines aimed to replace the LHC upon the conclusion of its research program. The Budker Institute of Nuclear Physics is actively involved in the development of the FCC-ee electron-positron collider. The Crab Waist (CR) scheme of the collision region that has been proposed by INP and will be implemented at FCC-ee is expected to provide high luminosity over a broad energy range. The status and development of the FCC project are described, and its parameters and limitations are discussed for the lepton collider in particular.

  3. Radio Detection of Ultra-High Energy Cosmic Rays

    CERN Document Server

    Falcke, Heino

    2008-01-01

    The radio technique for the detection of cosmic particles has seen a major revival in recent years. New and planned experiments in the lab and the field, such as GLUE, Anita, LUNASKA, Codalema, LOPES as well as sophisticated Monte Carlo experiments have produced a wealth of new information and I review here briefly some of the main results with the main focus on air showers. Radio emission of ultra-high energy cosmic particles offers a number of interesting advantages. Since radio waves suffer no attenuation, radio measurements allow the detection of very distant or highly inclined showers, can be used day and night, and provide a bolometric measure of the leptonic shower component. The LOPES experiment has detected the radio emission from cosmic rays, confirmed the geosynchrotron effect for extensive air showers, and provided a good calibration fomula to convert the radio signal into primary particle energy. Moreover, Monte Carlo simulations suggest that also the shower maximum and the particle composition c...

  4. Ultra high energy density and fast discharge nanocomposite capacitors

    Science.gov (United States)

    Tang, Haixiong; Sodano, Henry A.

    2013-04-01

    Nanocomposites containing high dielectric permittivity ceramics embedded in high breakdown strength polymers are currently of considerable interest as a solution for the development of high energy density capacitors. However, the improvement of dielectric permittivity comes at expense of the breakdown strength leading to limit the final energy density. Here, an ultra-high energy density nanocomposite was fabricated based on high aspect ratio barium strontium titanate nanowires. The pyroelectric phase Ba0.2Sr0.8TiO3 was chosen for the nanowires combined with quenched PVDF to fabricate high energy density nanocomposite. The energy density with 7.5% Ba0.2Sr0.8TiO3 nanowires reached 14.86 J/cc at 450 MV/m, which represented a 42.9% increase in comparison to the PVDF with an energy density of 10.4 J/cc at the same electric field. The capacitors have 1138% greater than higher energy density than commercial biaxial oriented polypropylene capacitors (1.2 J/cc at 640). These results demonstrate that the high aspect ratio nanowires can be used to produce nanocomposite capacitors with greater performance than the neat polymers thus providing a novel process for the development of future pulsed-power capacitors.

  5. On the acceleration of Ultra-High-Energy Cosmic Rays

    CERN Document Server

    Fraschetti, Federico

    2008-01-01

    Ultra High Energy Cosmic Rays (UHECRs) hit the Earth's atmosphere with energies exceeding $10^{18}$ eV. This is the same energy as carried by a tennis ball moving at 100 km/h, but concentrated on a sub-atomic particle. UHECRs are so rare (the flux of particles with $E > 10^{20}$ eV is 0.5/km$^2$/century) that only a few such particles have been detected over the past 50 years. Recently, the HiRes and Auger experiments have reported the discovery of a high-energy cut-off in the UHECR spectrum, and Auger has found an apparent clustering of the highest energy events towards nearby active galactic nuclei. Consensus is building that the highest energy particles are accelerated within the radio-bright lobes of these objects, but it remains unclear how this actually happens, and whether the cut-off is due to propagation effects or reflects an intrinsically physical limitation of the acceleration process. The low event statistics presently allows for many different plausible models; nevertheless observations are begi...

  6. Causality, renormalizability and ultra-high energy gravitational scattering

    Science.gov (United States)

    Hollowood, Timothy J.; Shore, Graham M.

    2016-05-01

    The amplitude { A }(s,t) for ultra-high energy scattering can be found in the leading eikonal approximation by considering propagation in an Aichelburg-Sexl gravitational shockwave background. Loop corrections in the QFT describing the scattered particles are encoded for energies below the Planck scale in an effective action which in general exhibits causality violation and Shapiro time advances. In this paper, we use Penrose limit techniques to calculate the full energy dependence of the scattering phase shift {{{\\Theta }}}{{scat}}(\\hat{s}), where the single variable \\hat{s}={Gs}/{m}2{b}d-2 contains both the CM energy s and impact parameter b, for a range of scalar QFTs in d dimensions with different renormalizability properties. We evaluate the high-energy limit of {{{\\Theta }}}{{scat}}(\\hat{s}) and show in detail how causality is related to the existence of a well-defined UV completion. Similarities with graviton scattering and the corresponding resolution of causality violation in the effective action by string theory are briefly discussed.

  7. Anisotropy vs chemical composition at ultra-high energies

    CERN Document Server

    Lemoine, Martin

    2009-01-01

    This paper proposes and discusses a test of the chemical composition of ultra-high energy cosmic rays that relies on the anisotropy patterns measured as a function of energy. In particular, we show that if one records an anisotropy signal produced by heavy nuclei of charge Z above an energy E_{thr}, one should record an even stronger (possibly much stronger) anisotropy at energies >E_{thr}/Z due to the proton component that is expected to be associated with the sources of the heavy nuclei. This conclusion remains robust with respect to the parameters characterizing the sources and it does not depend at all on the modelling of astrophysical magnetic fields. As a concrete example, we apply this test to the most recent data of the Pierre Auger Observatory. Assuming that the anisotropy reported above 55EeV is not a statistical accident, and that no significant anisotropy has been observed at energies 10^{45}Z^{-2}erg/s. Using this bound in conjunction with the above conclusions, we argue that the current PAO data...

  8. Causality, Renormalizability and Ultra-High Energy Gravitational Scattering

    CERN Document Server

    Hollowood, Timothy J

    2016-01-01

    The amplitude A(s,t) for ultra-high energy scattering can be found in the leading eikonal approximation by considering propagation in an Aichelburg-Sexl gravitational shockwave background. Loop corrections in the QFT describing the scattered particles are encoded for energies below the Planck scale in an effective action which in general exhibits causality violation and Shapiro time advances. In this paper, we use Penrose limit techniques to calculate the full energy dependence of the scattering phase shift Theta_scat(hat_s},, where the single variable hat_s = Gs/m^2 b^(d-2) contains both the CM energy s and impact parameter b, for a range of scalar QFTs in d dimensions with different renormalizability properties. We evaluate the high-energy limit of Theta_scat(hat_s) and show in detail how causality is related to the existence of a well-defined UV completion. Similarities with graviton scattering and the corresponding resolution of causality violation in the effective action by string theory are briefly disc...

  9. Prospects for detecting ultra-high-energy particles with FAST

    CERN Document Server

    James, C W; Ekers, R D

    2016-01-01

    The origin of the highest-energy particles in nature, the ultra-high-energy (UHE) cosmic rays, is still unknown. In order to resolve this mystery, very large detectors are required to probe the low flux of these particles - or to detect the as-yet unobserved flux of UHE neutrinos predicted from their interactions. The `lunar Askaryan technique' is a method to do both. When energetic particles interact in a dense medium, the Askaryan effect produces intense coherent pulses of radiation in the MHz--GHz range. By using radio telescopes to observe the Moon and look for nanosecond pulses, the entire visible lunar surface ($20$ million km$^2$) can be used as an UHE particle detector. A large effective area over a broad bandwidth is the primary telescope requirement for lunar observations, which makes large single-aperture instruments such as the Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) well-suited to the technique. In this contribution, we describe the lunar Askaryan technique and its unique obs...

  10. Ultra High Energy Cosmic Rays & Super-heavy Dark Matter

    CERN Document Server

    Marzola, Luca

    2016-01-01

    We reanalyse the prospects for upcoming Ultra-High Energy Cosmic Ray experiments in connection with the phenomenology of Super-heavy Dark Matter. We identify a set of observables well suited to reveal a possible anisotropy in the High Energy Cosmic Ray flux induced by the decays of these particles, and quantify their performance via Monte Carlo simulations that mimic the outcome of near-future and next-generation experiments. The spherical and circular dipoles are able to tell isotropic and anisotropic fluxes apart at a confidence level as large as $4\\sigma$ or $5\\sigma$, depending on the Dark Matter profile. The forward-to-backward flux ratio yields a comparable result for relatively large opening angles of about 40~deg, but it is less performing once a very large number of events is considered. We also find that an actual experiment employing these observables and collecting 300~events at 60~EeV would have a $50\\%$ chance of excluding isotropy against Super-heavy Dark Matter at a significance of at least $3...

  11. On the Origin of Ultra High Energy Cosmic Rays

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, T; Colgate, S; Li, H

    2009-07-01

    Turbulence-driven plasma accelerators produced by magnetized accretion disks around black holes are proposed as the mechanism mainly responsible for observed cosmic ray protons with ultra high energies 10{sup 19}-10{sup 21} eV. The magnetized disk produces a voltage comparable to these cosmic ray energies. Here we present a Poynting model in which this voltage provides all of the energy to create the jet-like structures observed to be ejected from accretion disks, and this voltage also accelerates ions to high energies at the top of the expanding structure. Since the inductive electric field E = -v x B driving expansion has no component parallel to the magnetic field B, ion acceleration requires plasma wave generation - either a coherent wave accelerator as recently proposed, or instability-driven turbulence. We find that turbulence can tap the full inductive voltage as a quasi-steady accelerator, and even higher energies are produced by transient events on this structure. We find that both MHD modes due to the current and ion diffusion due to kinetic instability caused by the non-Maxwellian ion distribution contribute to acceleration. We apply our results to extragalactic giant radiolobes, whose synchrotron emissions serve to calibrate the model, and we discuss extrapolating to other astrophysical structures. Approximate calculations of the cosmic ray intensity and energy spectrum are in rough agreement with data and serve to motivate more extensive MHD and kinetic simulations of turbulence that could provide more accurate cosmic ray and synchrotron spectra to be compared with observations. A distinctive difference from previous models is that the cosmic ray and synchrotron emissions arise from different parts of the magnetic structure, thus providing a signature for the model.

  12. On the Origin of Ultra High Energy Cosmic Rays II

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, T K; Colgate, S; Li, H; Bulmer, R H; Pino, J

    2011-03-08

    We show that accretion disks around Active Galactic Nuclei (AGNs) could account for the enormous power in observed ultra high energy cosmic rays {approx}10{sup 20} eV (UHEs). In our model, cosmic rays are produced by quasi-steady acceleration of ions in magnetic structures previously proposed to explain jets around Active Galactic Nuclei with supermassive black holes. Steady acceleration requires that an AGN accretion disk act as a dynamo, which we show to follow from a modified Standard Model in which the magnetic torque of the dynamo replaces viscosity as the dominant mechanism accounting for angular momentum conservation during accretion. A black hole of mass M{sub BH} produces a steady dynamo voltage V {proportional_to} {radical}M{sub BH} giving V {approx} 10{sup 20} volts for M{sub BH} {approx} 10{sup 8} solar masses. The voltage V reappears as an inductive electric field at the advancing nose of a dynamo-driven jet, where plasma instability inherent in collisionless runaway acceleration allows ions to be steadily accelerated to energies {approx} V, finally ejected as cosmic rays. Transient events can produce much higher energies. The predicted disk radiation is similar to the Standard Model. Unique predictions concern the remarkable collimation of jets and emissions from the jet/radiolobe structure. Given MBH and the accretion rate, the model makes 7 predictions roughly consistent with data: (1) the jet length; (2) the jet radius; (3) the steady-state cosmic ray energy spectrum; (4) the maximum energy in this spectrum; (5) the UHE cosmic ray intensity on Earth; (6) electron synchrotron wavelengths; and (7) the power in synchrotron radiation. These qualitative successes motivate new computer simulations, experiments and data analysis to provide a quantitative verification of the model.

  13. Simulation chain for acoustic ultra-high energy neutrino detectors

    Energy Technology Data Exchange (ETDEWEB)

    Neff, M., E-mail: max.neff@physik.uni-erlangen.de [Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Anton, G.; Enzenhöfer, A.; Graf, K.; Hößl, J.; Katz, U.; Lahmann, R. [Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany)

    2013-10-11

    Acoustic neutrino detection is a promising approach for large-scale ultra-high energy neutrino detectors in water. In this paper, a Monte Carlo simulation chain for acoustic neutrino detection devices in water is presented. It is designed within the SeaTray/IceTray software framework. Its modular architecture is highly flexible and makes it easy to adapt to different environmental conditions, detector geometries, and hardware. The simulation chain covers the generation of the acoustic pulse produced by a neutrino interaction and the propagation to the sensors within the detector. In this phase of the development, ambient and transient noise models for the Mediterranean Sea and simulations of the data acquisition hardware, similar to the one used in ANTARES/AMADEUS, are implemented. A pre-selection scheme for neutrino-like signals based on matched filtering is employed, as it can be used for on-line filtering. To simulate the whole processing chain for experimental data, signal classification and acoustic source reconstruction algorithms are integrated. In this contribution, an overview of the design and capabilities of the simulation chain will be given, and some applications and preliminary studies will be presented.

  14. Simulation Chain for Acoustic Ultra-high Energy Neutrino Detectors

    CERN Document Server

    Neff, M; Enzenhöfer, A; Graf, K; Hößl, J; Katz, U; Lahmann, R; 10.1016/j.nima.2012.11.147

    2013-01-01

    Acoustic neutrino detection is a promising approach for large-scale ultra-high energy neutrino detectors in water. In this article, a Monte Carlo simulation chain for acoustic neutrino detection devices in water is presented. It is designed within the SeaTray/IceTray software framework. Its modular architecture is highly flexible and makes it easy to adapt to different environmental conditions, detector geometries, and hardware. The simulation chain covers the generation of the acoustic pulse produced by a neutrino interaction and the propagation to the sensors within the detector. In this phase of the development, ambient and transient noise models for the Mediterranean Sea and simulations of the data acquisition hardware, similar to the one used in ANTARES/AMADEUS, are implemented. A pre-selection scheme for neutrino-like signals based on matched filtering is employed, as it can be used for on-line filtering. To simulate the whole processing chain for experimental data, signal classification and acoustic so...

  15. Study of Volumetrically Heated Ultra-High Energy Density Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rocca, Jorge J. [Colorado State Univ., Fort Collins, CO (United States)

    2016-10-27

    Heating dense matter to millions of degrees is important for applications, but requires complex and expensive methods. The major goal of the project was to demonstrate using a compact laser the creation of a new ultra-high energy density plasma regime characterized by simultaneous extremely high temperature and high density, and to study it combining experimental measurements and advanced simulations. We have demonstrated that trapping of intense femtosecond laser pulses deep within ordered nanowire arrays can heat near solid density matter into a new ultra hot plasma regime. Extreme electron densities, and temperatures of several tens of million degrees were achieved using laser pulses of only 0.5 J energy from a compact laser. Our x-ray spectra and simulations showed that extremely highly ionized plasma volumes several micrometers in depth are generated by irradiation of gold and Nickel nanowire arrays with femtosecond laser pulses of relativistic intensities. We obtained extraordinarily high degrees of ionization (e.g. we peeled 52 electrons from gold atoms, and up to 26 electrons from nickel atoms). In the process we generated Gigabar pressures only exceeded in the central hot spot of highly compressed thermonuclear fusion plasmas.. The plasma created after the dissolved wires expand, collide, and thermalize, is computed to have a thermal energy density of 0.3 GJ cm-3 and a pressure of 1-2 Gigabar. These are pressures only exceeded in highly compressed thermonuclear fusion plasmas. Scaling these results to higher laser intensities promises to create plasmas with temperatures and pressures exceeding those in the center of the sun.

  16. Implications of ultra-high energy neutrino flux constraints for Lorentz-invariance violating cosmogenic neutrinos

    CERN Document Server

    Gorham, P W; Allison, P; Beatty, J J; Belov, K; Besson, D Z; Binns, W R; Chen, P; Clem, J M; Hoover, S; Israel, M H; Nam, J; Saltzberg, D; Varner, G S; Vieregg, A G

    2012-01-01

    We consider the implications of Lorentz-invariance violation (LIV) on cosmogenic neutrino observations, with particular focus on the constraints imposed on several well-developed models for ultra-high energy cosmogenic neutrino production by recent results from the Antarctic Impulsive Transient Antenna (ANITA) long-duration balloon payload, and Radio Ice Cherenkov Experiment (RICE) at the South Pole. Under a scenario proposed originally by Coleman and Glashow, each lepton family may attain maximum velocities that can exceed the speed of light, leading to energy-loss through several interaction channels during propagation. We show that future observations of cosmogenic neutrinos will provide by far the most stringent limit on LIV in the neutrino sector. We derive the implied level of LIV required to suppress observation of predicted fluxes from several mainstream cosmogenic neutrino models, and specifically those recently constrained by the ANITA and RICE experiments. We simulate via detailed Monte Carlo code ...

  17. Acoustic detection of ultra-high energy cascades in ice

    Energy Technology Data Exchange (ETDEWEB)

    Boeser, S.

    2006-12-08

    Current underwater optical neutrino telescopes are designed to detect neutrinos from astrophysical sources with energies in the TeV range. Due to the low fluxes and small cross sections, no high energy neutrinos of extraterrestrial origin have been observed so far. Only the Cherenkov neutrino detectors on the km{sup 3} scale that are currently under construction will have the necessary volume to observe these rare interactions. For the guaranteed source of neutrinos from interactions of the ultra-high energy cosmic at EeV energies rays with the ambient cosmic microwave background, event rates of only one per year are expected in these experiments. To measure the flux and verify the predicted cross sections of these cosmogenic neutrinos, an observed volume of the order of 100 km{sup 3} will be necessary, that will not be feasible with existing detection techniques. Alternative methods are required to build a detector on these scales. One promising idea is to record the acoustic waves generated in hadronic or electromagnetic cascades following the neutrino interaction. The higher amplitudes of the sonic signal and the large expected absorption length of sound favour South Polar ice instead of sea water as a medium. The prerequisites for an estimate of the potential of such a detector are suitable acoustic sensors, a verification of the model of thermo-acoustic sound generation and a determination of the acoustic properties of the ice. In a theoretical derivation the mechanism of thermo-elastic excitation of acoustic waves was shown to be equivalent for isotropic solids and liquids. Following a detailed analysis of the existing knowledge a simulation study of a hybrid optical-radio-acoustic detector has been performed. Ultrasonic sensors dedicated to in-ice application were developed and have been used to record acoustic signals from intense proton and laser beams in water and ice. With the obtained experience, the hitherto largest array of acoustic sensors and

  18. A GPU-based Calculation Method for Near Field Effects of Cherenkov Radiation Induced by Ultra High Energy Cosmic Neutrinos

    CERN Document Server

    Hu, Chia-Yu; Chen, Pisin

    2010-01-01

    The radio approach for detecting the ultra-high energy cosmic neutrinos has become a mature field. The Cherenkov signals in radio detection are originated from the charge excess of particle showers due to Askaryan effect. The conventional way of calculating the Cherenkov pulses by making Fraunhofer approximation fails when the sizes of the elongated showers become comparable with the detection distances. We present a calculation method of Cherenkov pulses based on the finite-difference time-domain (FDTD) method, and attain a satisfying effeciency via the GPU- acceleration. Our method provides a straightforward way of the near field calculation, which would be important for ultra high energy particle showers, especailly the electromagnetic showers induced by the high energy leptons produced in the neutrino charge current interactions.

  19. Ultra-high energy cosmic rays threshold in Randers-Finsler space

    Institute of Scientific and Technical Information of China (English)

    CHANG Zhe; LI Xin

    2009-01-01

    Kinematics in Finsler space is used to study the propagation of ultra high energy cosmic rays particles through the cosmic microwave background radiation. We find that the GZK threshold is lifted dramatically in Randers-Finsler space. A tiny deformation of spacetime from Minkowskian to Finslerian allows more ultra-high energy cosmic rays particles to arrive at the earth. It is suggested that the lower bound of particle mass is related with the negative second invariant speed in Randers-Finsler space.

  20. Computational Schemes for the Propagation of Ultra High Energy Cosmic Rays

    CERN Document Server

    Aloisio, R

    2012-01-01

    We discuss the problem of ultra high energy particles propagation in astrophysical backgrounds. We present two different computational schemes based on both kinetic and Monte Carlo approaches. The kinetic approach is an analytical computation scheme based on the hypothesis of continuos energy losses while the Monte Carlo scheme takes into account also the stochastic nature of particle interactions. These schemes, that give quite reliable results, enable the computation of fluxes keeping track of the different primary and secondary components, providing a fast and useful workbench to study Ultra High Energy Cosmic Rays.

  1. The moon as a detector of ultra-high-energy neutrinos

    NARCIS (Netherlands)

    Scholten, Olaf

    2012-01-01

    Cosmogenic particles at ultra-high energies (UHE, E >1020 eV, about 1 Joule) are the messengers of the most energetic processes in the universe. Their energy is orders of magnitude higher than reachable at CERN. The quest is to find their origin. Neutrinos are especially suited for this as they fly

  2. The moon as a detector of ultra-high-energy neutrinos

    NARCIS (Netherlands)

    Scholten, Olaf; Bijker, R

    2012-01-01

    Cosmogenic particles at ultra-high energies (UHE, E > 10(20) eV, about 1 Joule) are the messengers of the most energetic processes in the universe. Their energy is orders of magnitude higher than reachable at CERN. The quest is to find their origin. Neutrinos are especially suited for this as they f

  3. Ultra-high energy interaction on accelerators and in cosmic rays.

    Science.gov (United States)

    Nikolskij, S. I.

    1989-03-01

    The violations of Feinman scaling, accelerator data concerning multiproduction hadron scaling, and relations between the real and imaginary parts of the forward elastic scattering amplitude in pp collisions are discussed. Experimental cosmic ray data indicate the existence of some new energy-threshold processes of the multiproduction of photons and leptons in hadron interaction at ultra-high energies.

  4. Lunar detection of ultra-high-energy cosmic rays and neutrinos

    NARCIS (Netherlands)

    Bray, J. D.; Alvarez-Muñiz, J.; Buitink, S.; Dagkesamanskii, R. D.; Ekers, R. D.; Falcke, H.; Gayley, K. G.; Huege, T.; James, C. W.; Mevius, M.; Mutel, R. L.; Protheroe, R. J.; Scholten, O.; Spencer, R. E.; ter Veen, S.

    2014-01-01

    The origin of the most energetic particles in nature, the ultra-high-energy (UHE) cosmic rays, is still a mystery. Due to their extremely low flux, even the 3,000 km^2 Pierre Auger detector registers only about 30 cosmic rays per year with sufficiently high energy to be used for directional studies.

  5. Ultra-high-energy cosmic ray and neutrino physics using the Moon

    NARCIS (Netherlands)

    Scholten, O.; BarronPalos, L; Bijker, R; Fossion, R; Lizcano, D

    2010-01-01

    The intriguing mystery of ultra-high energy (UHE) cosmic particles is the nature of their sources. In this presentation we indicate how these UHE particles, in order to uncover their sources, can be detected using radio observations of the Moon. When high-energy cosmic rays impinge on a dielectric,

  6. Ultra high energy primary composition and interaction studies with DUMAND

    Science.gov (United States)

    Allkofer, O. C.; Grieder, P. K. F.

    It is pointed out that the addition of a 'shallow muon array' or the Fly's Eye to DUMAND would maximize the amount of information gathered and would make possible a unique interpretation of the new acquired data. In conjunction with the shallow muon array, DUMAND would make it possible to determine the fraction of high-energy muons in showers, the shape of their energy spectrum, and the primary energy dependence of these observables, as well as various correlations.

  7. Observing Ultra High Energy Cosmic Particles from Space: SEUSO, the Super Extreme Universe Space Observatory Mission

    CERN Document Server

    Santangelo, Andrea

    2009-01-01

    The experimental search for ultra high energy cosmic messengers, from $E\\sim 10^{19}$ eV to beyond $E\\sim 10^{20}$ eV, at the very end of the known energy spectrum, constitutes an extraordinary opportunity to explore a largely unknown aspect of our universe. Key scientific goals are the identification of the sources of ultra high energy particles, the measurement of their spectra and the study of galactic and local intergalactic magnetic fields. Ultra high energy particles might, also, carry evidence of unknown physics or of exotic particles relics of the early universe. To meet this challenge a significant increase in the integrated exposure is required. This implies a new class of experiments with larger acceptances and good understanding of the systematic uncertainties. Space based observatories can reach the instantaneous aperture and the integrated exposure necessary to systematically explore the ultra high energy universe. In this paper, after briefly summarising the science case of the mission, we desc...

  8. Implementation of trigger for detection of ultra high energy cosmic rays with LOFAR

    NARCIS (Netherlands)

    Singh, K.; Bähren, L.; Falcke, H.; Horneffer, A.; Kooistra, E.; Scholten, O.

    2008-01-01

    Using all stations of LOFAR we are planning to explore the possibility of using Moon as a detector of ultra high energy (>10 21 eV) cosmic rays. The idea is to cover the whole visible lunar surface and to look for short pulses of Cherenkov radiation emitted by showers induced just below the surface

  9. Can new heavy gauge bosons be observed in ultra-high energy cosmic neutrino events?

    CERN Document Server

    Ježo, T; Lyonnet, F; Montanet, F; Schienbein, I; Tartare, M

    2014-01-01

    A wide range of models beyond the Standard Model predict charged and neutral resonances, generically called $W'$- and $Z'$-bosons, respectively. In this paper we study the impact of such resonances on the deep inelastic scattering of ultra-high energy neutrinos as well as on the resonant charged current $\\bar\

  10. ULTRA-HIGH ENERGY COSMIC RAY AND NEUTRINO DETECTION USING THE MOON : FIRST RESULTS

    NARCIS (Netherlands)

    Scholten, O.; Bacelar, J.; Singh, K.; Al Yahyaoui, R.; Buitink, S.; Falcke, H.; Braun, R.; de Bruyn, A. G.; Strom, R. G.; Stappers, B.

    2009-01-01

    We show that at wavelengths comparable to the length of the shower produced by an Ultra-High Energy cosmic ray or neutrino, radio signals are an extremely efficient way to detect these particles. First results are presented of an analysis of 20 hours of observation data for NuMoon project using the

  11. Ultra-high-energy cosmic ray and neutrino detection using the Moon

    NARCIS (Netherlands)

    Scholten, Olaf; Buitink, S.; Falcke, H.; James, C. W.; Mevius, M.; Singh, K.; Stappers, B.; Ter Veen, S.

    2011-01-01

    When Ultra-high-energy (UHE) neutrinos or cosmic rays interact in the lunar surface they will initiate a particle cascade. These cascades have a sizeable negative charge excess and radiate coherent Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequency window for o

  12. Lunar detection of ultra-high-energy cosmic rays and neutrinos with the Square Kilometre Array

    NARCIS (Netherlands)

    Bray, J.; Alvarez-Muniz, J.; Buitink, S.; Dagkesamanskii, R.; Ekers, R. D.; Falcke, H. D. E.; Gayley, K.; Huege, T.; James, C. W.; Mevius, M.; Mutel, R.; Protheroe, R. J.; Scholten, O.; Schroeder, F.; Spencer, R. E.; ter Veen, S.

    2014-01-01

    The origin of the most energetic particles in nature, the ultra-high-energy (UHE) cosmic rays, is still a mystery. Only the most energetic of these have sufficiently small angular deflections to be used for directional studies, and their flux is so low that even the 3,000 km^2 Pierre Auger detector

  13. Ultra-High Energy Cosmic Rays: Results and Prospects

    CERN Document Server

    Kampert, Karl-Heinz

    2014-01-01

    Recent advances in measuring and interpreting cosmic rays from the spectral ankle to the highest energies are briefly reviewed. A knee of heavy primaries and an ankle of light primaries have been observed at about 10^{17} eV. The light component starts to dominate the flux at the ankle in the all particle spectrum at about 4x10^{18} eV and sheds light on the transition from galactic to extragalactic cosmic rays. The prime question at the highest energies is about the origin of the flux suppression observed at E > 4x10^{19} eV. Is this the long awaited GZK-effect or the exhaustion of sources? The key to answering this question is again the still largely unknown mass composition at the highest energies. Data from different observatories don't quite agree and common efforts have been started to settle that question. The high level of isotropy observed even at the highest energies challenges models of a proton dominated composition if extragalactic magnetic fields are on the order of a few nG or less. We will dis...

  14. Fossil AGN jets as ultra high energy particle accelerators

    OpenAIRE

    2007-01-01

    Remnants of AGN jets and their surrounding cocoons leave colossal magnetohydrodynamic (MHD) fossil structures storing total energies ~10^{60} erg. The original active galacic nucleus (AGN) may be dead but the fossil will retain its stable configuration resembling the reversed-field pinch (RFP) encountered in laboratory MHD experiments. In an RFP the longitudinal magnetic field changes direction at a critical distance from the axis, leading to magnetic re-connection there, and to slow decay of...

  15. New physics with ultra-high-energy neutrinos

    Directory of Open Access Journals (Sweden)

    D. Marfatia

    2015-09-01

    Full Text Available Now that PeV neutrinos have been discovered by IceCube, we optimistically entertain the possibility that neutrinos with energy above 100 PeV exist. We evaluate the dependence of event rates of such neutrinos on the neutrino-nucleon cross section at observatories that detect particles, atmospheric fluorescence, or Cherenkov radiation, initiated by neutrino interactions. We consider how (i a simple scaling of the total standard model neutrino-nucleon cross section, (ii a new elastic neutral current interaction, and (iii a new completely inelastic interaction, individually impact event rates.

  16. New physics with ultra-high-energy neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Marfatia, D., E-mail: dmarf8@hawaii.edu [Department of Physics and Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States); McKay, D.W. [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States); Weiler, T.J. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States)

    2015-09-02

    Now that PeV neutrinos have been discovered by IceCube, we optimistically entertain the possibility that neutrinos with energy above 100 PeV exist. We evaluate the dependence of event rates of such neutrinos on the neutrino-nucleon cross section at observatories that detect particles, atmospheric fluorescence, or Cherenkov radiation, initiated by neutrino interactions. We consider how (i) a simple scaling of the total standard model neutrino-nucleon cross section, (ii) a new elastic neutral current interaction, and (iii) a new completely inelastic interaction, individually impact event rates.

  17. Testing for uniformity of Ultra-High Energy Cosmic Ray arrival directions

    CERN Document Server

    Ivanov, A A

    2016-01-01

    Arrival directions of ultra-high energy cosmic rays (UHECRs) exhibit mainly an isotropic distribution with some small deviations in particular energy bins. In this paper, the Yakutsk array data are tested for circular uniformity of arrival directions in right ascension using 2 methods appropriate for the energy ranges below and above $10^{18}$ eV. No statistically significant deviation from uniformity is found in the arrival directions of cosmic rays (CRs) detected within the observation period 1974--2000.

  18. RECENT DEVELOPMENTS IN ULTRA-HIGH ENERGY NEUTRINO ASTRONOMY

    Directory of Open Access Journals (Sweden)

    Peter K. F. Grieder

    2013-12-01

    Full Text Available We outline the current situation in ultrahigh energy (UHE cosmic ray physics, pointing out the remaining problems, in particular the puzzle concerning the origin of the primary radiation and the role of neutrino astronomy for locating the sources. Various methods for the detection of UHE neutrinos are briefly described and their merits compared. We give an account of the achievements of the existing optical Cherenkov neutrino telescopes, outline the possibility of using air fluorescence and particle properties of air showers to identify neutrino induced events, and discuss various pioneering experiments employing radio and acoustic detection of extremely energetic neutrinos. The next generation of space, ground and sea based neutrino telescopes now under construction or in the planning phase are listed.

  19. Spectrum and Composition of Ultra-high Energy Cosmic Rays from Semi-relativistic Hypernovae

    CERN Document Server

    Liu, Ruo-Yu

    2011-01-01

    It has been suggested that hypernova remnants, with a substantial amount of energy in semi-relativistic ejecta, can accelerate intermediate mass or heavy nuclei to ultra-high energies and provide sufficient amount of energy in cosmic rays to account for the observed flux. We here calculate the expected energy spectrum and chemical composition of ultra-high energy cosmic rays from such semi-relativistic hypernovae. With a chemical composition equal to that of the hypernova ejecta and a flat or hard spectrum for cosmic rays at the sources, the spectrum and composition of the propagated cosmic rays observed at the Earth can be compatible with the measurements by the Pierre Auger Observatory.

  20. Propagation and Signatures of Ultra High Energy Cosmic Rays

    CERN Document Server

    Berezinsky, Vladimir; Grigorieva, S

    2004-01-01

    We study the extragalactic protons with universal spectrum, which is independent of mode of propagation, when distance between sources is less than the propagation lengths, such as energy attenuation length or diffusion length (for propagation in magnetic fields). The propagation features in this spectrum, the GZK cutoff, dip and bump, are studied with help of modification factor, which weakly depends on the generation spectrum index $\\gamma_g$. We argue that from the above features the dip is the most model-independent one. For the power-law generation spectrum with $\\gamma_g=2.7$ the dip is very well confirmed by the data of all existing detectors, which gives the strong evidence for extragalactic protons propagating through CMB. We develop the AGN model for origin of UHECR, which successfully explains the observed spectra up to $1\\times 10^{20}$ eV and transition from galactic to extragalactic cosmic rays. The calculated spectrum has the GZK cutoff, and the AGASA excess of events at $E \\gsim 1\\times 10^{20...

  1. Ultra-High Energy Astrophysical Neutrino Detection, and the Search for Lorentz Invariance Violations

    CERN Document Server

    Hanson, J C

    2016-01-01

    A growing class of ultra-high energy neutrino (UHE-nu) observatories based on the Askaryan effect and Antarctic ice is able to search for Lorentz invariance violation (LIV). The ARA, ARIANNA, ANITA and EVA collaborations have the power to constrain the Standard Model Extension (SME) by measuring the flux and energy distribution of neutrinos created through the GZK process. The future expansion of ARA, at the South Pole, pushes the discovery potential further.

  2. Ultra-high energy particle collisions in a regular spacetime without blackholes or naked singularities

    CERN Document Server

    Patil, Mandar

    2012-01-01

    We investigate here the particle acceleration and collisions with extremely large center of mass energies in a perfectly regular spacetime containing neither singularity nor an event horizon. The ultra-high energy collisions of particles near the event horizon of extremal Kerr blackhole, and also in many other examples of extremal blackholes have been investigated and reported recently. We studied an analogous particle acceleration process in the Kerr and Reissner- Nordstrom spacetimes without horizon, containing naked singularities. Further to this, we show here that the particle acceleration and collision process is in fact independent of blackholes and naked singularities, and can happen in a fully regular spacetime containing neither of these. We derive the conditions on the general static spherically symmetric metric for such a phenomena to happen. We show that in order to have ultra-high energy collisions it is necessary for the norm of the timelike Killing vector to admit a maximum with a vanishingly s...

  3. Gravitational Radiation from Ultra High Energy Cosmic Rays in Models with Large Extra Dimensions

    CERN Document Server

    Koch, B; Bleicher, M; Koch, Ben; Drescher, Hans-Joachim; Bleicher, Marcus

    2006-01-01

    The effects of classical gravitational radiation in models with large extra dimensions are investigated for ultra high energy cosmic rays (CRs). The cross sections are implemented into a simulation package (SENECA) for high energy hadron induced CR air showers. We predict that gravitational radiation from quasi-elastic scattering could be observed at incident CR energies above $10^9$ GeV for a setting with more than two extra dimensions. It is further shown that this gravitational energy loss can alter the energy reconstruction for CR energies $E_{\\rm CR}\\ge 5\\cdot 10^9$ GeV.

  4. Magnetowave Induced Plasma Wakefield Acceleration for Ultra High Energy Cosmic Rays

    CERN Document Server

    Chang, Feng-Yin; Lin, Guey-Lin; Reil, Kevin; Sydora, Richard

    2007-01-01

    Magnetowave induced plasma wakefield acceleration (MPWA) in a relativistic astrophysical outflow has been proposed as a viable mechanism for the acceleration of cosmic particles to ultra high energies. Here we present simulation results that clearly demonstrate the viability of this mechanism for the first time. We invoke the high frequency and high speed whistler mode for the driving pulse. The plasma wakefield so induced validates precisely the theoretical prediction. We show that under appropriate conditions, the plasma wakefield maintains very high coherence and can sustain high-gradient acceleration over a macroscopic distance. Invoking gamma ray burst (GRB) as the source, we show that MPWA production of ultra high energy cosmic rays (UHECR) beyond ZeV 10^21 eV is possible.

  5. A compact acoustic calibrator for ultra-high energy neutrino detection

    CERN Document Server

    Adrián-Martínez, S; Bou-Cabo, M; Larosa, G; Llorens, C D; Martínez-Mora, J A

    2012-01-01

    With the aim to optimize and test the method of acoustic detection of ultra-high energy neutrinos in underwater telescopes a compact acoustic transmitter array has been developed. The acoustic parametric effect is used to reproduce the acoustic signature of an ultra-high-energy neutrino interaction. Different reseach and development studies are presented in order to show the viability of the parametric sources technique to deal with the difficulties of the acoustic signal generation: a very directive transient bipolar signal with pancake directivity. The design, construction and characterization of the prototype are described, including simulation of the propagation of an experimental signal, measured in a pool, over a distance of 1 km. Following these studies, next steps will be testing the device in situ, in underwater neutrino telescope, or from a vessel in a sea campaign.

  6. Can new heavy gauge bosons be observed in ultra-high energy cosmic neutrino events?

    Science.gov (United States)

    Ježo, T.; Klasen, M.; Lyonnet, F.; Montanet, F.; Schienbein, I.; Tartare, M.

    2014-04-01

    A wide range of models beyond the Standard Model predict charged and neutral resonances, generically called W' and Z' bosons, respectively. In this paper we study the impact of such resonances on the deep inelastic scattering of ultra-high energy neutrinos as well as on the resonant charged current ν¯ee- scattering (Glashow resonance). We find that the effects of such resonances cannot be observed with the Pierre Auger Observatory or any foreseeable upgrade of it.

  7. Measurement of ultra-high energy cosmic rays: An experimental summary and prospects

    Directory of Open Access Journals (Sweden)

    Fukushima M.

    2013-06-01

    Full Text Available Measurements of Ultra-High Energy Cosmic Rays achieved remarkable progress in the last 10 years. Physicists, gathered from around the world in the symposium UHECR-2012 held at CERN on February 13-16 2012, reported their most up-to-date observations, discussed the meaning of their findings, and identified remaining problems and future challenges in this field. This paper is a part of the symposium proceedings on the experimental summary and future prospects of the UHECR study.

  8. Current non-conservation effects in ultra-high energy neutrino interactions

    CERN Document Server

    Fiore, R

    2010-01-01

    The overall hardness scale of the ultra-high energy neutrino-nucleon interactions is usually estimated as $Q^2\\sim m_W^2$. The effect of non-conservation of weak currents pushes this scale up to the top quark mass squared and changes dynamics of the scattering process. The Double Leading Log Approximation provides simple and numerically accurate formula for the top-bottom contribution to the total cross section $\\sigma^{\

  9. On the prospects of ultra-high energy cosmic rays detection by high altitude antennas

    CERN Document Server

    Motloch, P; Privitera, P

    2013-01-01

    Radio emission from Ultra-High Energy Cosmic Rays (UHECR) showers detected after specular reflection off the Antarctic ice surface has been recently demonstrated by the ANITA balloon-borne experiment. An antenna observing a large area of ice or water from a mountaintop, a balloon or a satellite may be competitive with more conventional techniques. We present an estimate of the exposure of a high altitude antenna, which provides insight on the prospects of this technique for UHECR detection.

  10. Estimation Prospects of the Source Number Density of Ultra-high-energy Cosmic Rays

    OpenAIRE

    Takami, Hajime; Sato, Katsuhiko

    2007-01-01

    We discuss the possibility of accurately estimating the source number density of ultra-high-energy cosmic rays (UHECRs) using small-scale anisotropy in their arrival distribution. The arrival distribution has information on their source and source distribution. We calculate the propagation of UHE protons in a structured extragalactic magnetic field (EGMF) and simulate their arrival distribution at the Earth using our previously developed method. The source number density that can best reprodu...

  11. Energy reconstruction of hadron-initiated showers of ultra-high energy cosmic rays

    CERN Document Server

    Ros, G; Supanitsky, A D; del Peral, L; Rodríguez-Frías, M D

    2015-01-01

    The current methods to determine the primary energy of ultra-high energy cosmic rays (UHECRs) are different when dealing with hadron or photon primaries. The current experiments combine two different techniques, an array of surface detectors and fluorescence telescopes. The latter allow an almost calorimetric measurement of the primary energy. Thus, hadron-initiated showers detected by both type of detectors are used to calibrate the energy estimator from the surface array (usually the interpolated signal at a certain distance from the shower core S(r0)) with the primary energy. On the other hand, this calibration is not feasible when searching for photon primaries since no high energy photon has been unambiguously detected so far. Therefore, pure Monte Carlo parametrizations are used instead. In this work, we present a new method to determine the primary energy of hadron-induced showers in a hybrid experiment based on a technique previously developed for photon primaries. It consists on a set of calibration ...

  12. Dark matter distribution in the universe and ultra-high energy cosmic rays

    CERN Document Server

    Blasi, P

    2000-01-01

    Two of the greatest mysteries of modern physics are the origin of the dark matter in the universe and the nature of the highest energy particles in the cosmic ray spectrum. We discuss here possible direct and indirect connections between these two problems, with particular attention to two cases: in the first we study the local clustering of possible sources of ultra-high energy cosmic rays (UHECRs) driven by the local dark matter overdensity. In the second case we study the possibility that UHECRs are directly generated by the decay of weakly unstable super heavy dark matter.

  13. Searching for signals of magnetic lensing in ultra-high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Golup, Geraldina; Harari, Diego; Mollerach, Silvia; Roulet, Esteban, E-mail: golupg@ib.cnea.gov.ar, E-mail: harari@cab.cnea.gov.ar, E-mail: mollerach@cab.cnea.gov.ar, E-mail: roulet@cab.cnea.gov.ar [CONICET and Centro Atómico Bariloche, Av. Bustillo 9500, 8400, S. C. de Bariloche (Argentina)

    2011-07-01

    Ultra-high energy cosmic rays are mostly charged particles and they are therefore deflected by magnetic fields on their path from their sources to Earth. An interesting phenomenon arising from these deflections is the appearance of multiple images of a source, i.e. cosmic rays with the same energy coming from the same source that can arrive to the Earth from different directions. In this work we present a technique to identify secondary images, produced by the regular component of the galactic magnetic field, benefiting from the fact that near caustics the flux is significantly magnified.

  14. The Pierre Auger Observatory: Results on Ultra-High Energy Cosmic Rays

    CERN Document Server

    Bluemer, Johannes

    2008-01-01

    The focus of this article is on recent results on ultra-high energy cosmic rays obtained with the Pierre Auger Observatory. The world's largest instrument of this type and its performance are described. The observations presented here include the energy spectrum, the primary particle composition, limits on the fluxes of photons and neutrinos and a discussion of the anisotropic distribution of the arrival directions of the most energetic particles. Finally, plans for the construction of a Northern Auger Observatory in Colorado, USA, are discussed.

  15. Features of the galactic magnetic field regarding deflections of ultra-high-energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Wirtz, Marcus; Erdmann, Martin; Mueller, Gero; Urban, Martin [III. Physikalisches Institut A, RWTH Aachen University (Germany)

    2016-07-01

    Most recent models of the galactic magnetic field have been derived from Faraday rotation measurements and imply strong deflections even for ultra-high energy cosmic rays. We investigate the characteristics of the different field parametrizations and point out similarities and interesting features. Among them are extragalactic regions which are invisible for an Earth bound observation and the transition from diffuse to ballistic behaviour in the 1 EeV energy regime. Applying this knowledge to a directional analysis, there are indications for deflection patterns by the galactic magnetic field in cosmic ray arrival directions measured by the Pierre Auger Observatory.

  16. CONSTRAINTS ON THE SOURCE OF ULTRA-HIGH-ENERGY COSMIC RAYS USING ANISOTROPY VERSUS CHEMICAL COMPOSITION

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ruo-Yu; Wang, Xiang-Yu [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Taylor, Andrew M. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Lemoine, Martin [Institut d' Astrophysique de Paris, CNRS, UPMC, 98 bis Boulevard Arago, F-75014 Paris (France); Waxman, Eli, E-mail: lemoine@iap.fr [Physics Faculty, Weizmann Institute, P.O. Box 26, Rehovot 7600 (Israel)

    2013-10-20

    The joint analysis of anisotropy signals and chemical composition of ultra-high-energy cosmic rays offers strong potential for shedding light on the sources of these particles. Following up on an earlier idea, this paper studies the anisotropies produced by protons of energy >E/Z, assuming that anisotropies at energy >E have been produced by nuclei of charge Z, which share the same magnetic rigidity. We calculate the number of secondary protons produced through photodisintegration of the primary heavy nuclei. Making the extreme assumption that the source does not inject any proton, we find that the source(s) responsible for anisotropies such as reported by the Pierre Auger Observatory should lie closer than ∼20-30, 80-100, and 180-200 Mpc if the anisotropy signal is mainly composed of oxygen, silicon, and iron nuclei, respectively. A violation of this constraint would otherwise result in the secondary protons forming a more significant anisotropy signal at lower energies. Even if the source were located closer than this distance, it would require an extraordinary metallicity ∼> 120, 1600, and 1100 times solar metallicity in the acceleration zone of the source, for oxygen, silicon, and iron, respectively, to ensure that the concomitantly injected protons do not produce a more significant low-energy anisotropy. This offers interesting prospects for constraining the nature and the source of ultra-high-energy cosmic rays with the increase in statistics expected from next-generation detectors.

  17. Radio galaxies and the origin of ultra-high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Massaglia, S. [Dipartimento di Fisica Generale dell' Universita, 10125 Torino (Italy)

    2007-03-15

    Among the possible sources of ultra-high energy cosmic rays are the hot-spots of Fanaroff-Rlley II radio galaxies. These regions meet the requirements of size, magnetic field intensity and presence of strong shocks for accelerating particles up to energies that exceed 10{sup 21} eV. On the other hand, the interaction with the photons of the Cosmic Microwave Background radiation, the Greisen-Zatsepin-Kuz'min effect, dictates that the sources of particles with energy above 4x10{sup 19} eV must be within 130 Mpc, at most. There are not very many FR II radio galaxies within this distance, i.e. 15 objects. Once the statistics of events for detection of cosmic rays at these energies will have reached reasonable levels (see the Pierre Auger Experiment [J.W. Cronin, Nucl. Phys. B 138 (2005) 465]), looking for the arrival directions will either confirm or rule out the role of FR II hot-spots as sources of ultra-high energy cosmic rays.

  18. The influence of ultra-high-energy cosmic rays on star formation in the early universe

    CERN Document Server

    Vasiliev, E O; Shchekinov, Yu.A.

    2006-01-01

    The presence of ultra-high-energy cosmic rays (UHECR) results in an increase in the degree of ionization in the post-recombination Universe, which stimulates the efficiency of the production of H$_2$ molecules and the formation of the first stellar objects. As a result, the onset of the formation of the first stars is shifted to higher redshifts, and the masses of the first stellar systems decrease. As a consequence, a sufficient increase in the ionizing radiation providing the reionization of the Universe can take place. We discuss possible observational manifestations of these effects and their dependence on the parameters of UHECR.

  19. Diffuse ultra-high energy neutrino fluxes and physics beyond the Standard Model

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Atri, E-mail: atri@hri.res.i [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Choubey, Sandhya; Gandhi, Raj [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Watanabe, Atsushi [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

    2010-06-07

    We study spectral distortions of diffuse ultra-high energy (UHE) neutrino flavour fluxes resulting due to physics beyond the Standard Model (SM). Even large spectral differences between flavours at the source are massaged into a common shape at earth by SM oscillations, thus, any significant observed spectral differences are an indicator of new physics present in the oscillation probability during propagation. Lorentz symmetry violation (LV) and neutrino decay are examples, and result in significant distortion of the fluxes and of the well-known bounds on them, which may allow UHE detectors to probe LV parameters, lifetimes and the mass hierarchy over a broad range.

  20. Diffuse Ultra-High Energy Neutrino Fluxes and Physics Beyond the Standard Model

    CERN Document Server

    Bhattacharya, Atri; Gandhi, Raj; Watanabe, Atsushi

    2009-01-01

    We study the effects of physics beyond the Standard Model on diffuse fluxes of neutrino flavours from ultra-high-energy (UHE) sources. Using neutrino decay and Lorentz symmetry violation (LV) as examples, we show that they would result in significant spectral distortion of the well-known bounds on such fluxes. This would allow UHE detectors with some flavour detection sensitivity to probe lifetimes and LV parameters over a broad range beyond present bounds and the neutrino mass hierarchy via distinctive signatures. We indicate how this method may be used to study other new physics scenarios.

  1. Ultra-high energy cosmic rays clustering, GUT scale and neutrino masses

    CERN Document Server

    Fodor, Z

    2002-01-01

    The clustering of ultra high energy (above 5\\cdot 10^{19} eV) cosmic rays (UHECR) suggests that they might be emitted by compact sources. We present a statistical analysis on the source density based on the multiplicities. The propagation of UHECR protons is studied in detail. The UHECR spectrum is consistent with the decay of GUT scale particles and/or with the Z-burst. The predicted GUT mass is m_X=10^b GeV, where b=14.6_{-1.7}^{+1.6}. Our neutrino mass prediction depends on the origin of the power part of the spectrum: m_\

  2. Connecting blazars with ultra high energy cosmic rays and astrophysical neutrinos

    CERN Document Server

    Resconi, Elisa; Padovani, Paolo; Giommi, Paolo; Caccianiga, Lorenzo

    2016-01-01

    We present evidence of a direct connection between high energy $\\gamma$-ray emitting blazars, very high energy neutrinos, and ultra high energy cosmic rays. We first identify potential hadronic sources by selecting $\\gamma$-ray emitters, that are in spatial coincidence with neutrinos detected by IceCube. These are then correlated with ultra high energy cosmic rays from the Pierre Auger Observatory and the Telescope Array scanning in $\\gamma$-ray flux $F_{\\gamma}$ and angular separation between sources and cosmic rays $\\theta$. A maximal excess of 80 cosmic rays (41.9 expected) is observed for the second catalog of hard Fermi-LAT (2FHL) objects with $F_\\gamma\\left(>50\\:\\mathrm{GeV}\\right)\\geq1.8\\times10^{-11}\\:\\mathrm{ph}\\,\\mathrm{cm}^{-2}\\,\\mathrm{s}^{-1}$ and $\\theta\\leq10^{\\circ}$. The probability for this to happen is $1.6 \\times 10^{-5}$, which translates to $5.5 \\times 10^{-4}$ ($3.26\\sigma$) after compensation for trials. No excess of cosmic rays is instead observed for $\\gamma$-ray blazars not in spati...

  3. FORTE satellite constraints on ultra-high energy cosmic particle fluxes

    CERN Document Server

    Lehtinen, N G; Jacobson, A R; Roussel-Dupre, R A; Lehtinen, Nikolai G.; Gorham, Peter W.; Jacobson, Abram R.; Roussel-Dupre, Robert A.

    2004-01-01

    The FORTE (Fast On-orbit Recording of Transient Events) satellite records bursts of electromagnetic waves arising from near the Earth's surface in the radio frequency (RF) range of 30 to 300 MHz with a dual polarization antenna. We investigate the possible RF signature of ultra-high energy cosmic-ray particles in the form of coherent Cherenkov radiation from cascades in ice. We calculate the sensitivity of the FORTE satellite to ultra-high energy (UHE) neutrino fluxes at different energies beyond the Greisen-Zatsepin-Kuzmin (GZK) cutoff. Some constraints on supersymmetry model parameters are also estimated due to the limits that FORTE sets on the UHE neutralino flux. The FORTE database consists of over 4 million recorded events to date, including in principle some events associated with UHE neutrinos. We search for candidate FORTE events in the period from September 1997 to December 1999. The candidate production mechanism is via coherent VHF radiation from a UHE neutrino shower in the Greenland ice sheet. We...

  4. Cosmological fast radio bursts and ultra-high energy cosmic rays

    CERN Document Server

    Li, Xiang; He, Hao-Ning; Fan, Yi-Zhong; Wei, Da-Ming

    2013-01-01

    The existence of fast radio bursts (FRBs), a new type of cosmological transients, has been established recently. The report of two FRB candidates following two long Gamma-ray Bursts (GRBs) in a search for possible connection between FRBs and GRBs, if confirmed in the future, will favor the origin of delayed collapse of supramassive neutron star (SMNS) to a black hole. The energy injected into the surrounding material by a SMNS will be in order of 1e52 erg unless the gravitational wave radiation is dominant. Energetic forward shock will be driven and ultra-high energy cosmic rays can be accelerated. Moreover, benefit from a very high rate of FRBs (i.e., 1e4 sky^-1 day^-1), these ultra-high energy cosmic rays likely contribute significantly to the observed ones. We also suggest that the mergers of double neutron stars, even if they are irrelevant to FRBs, can play an important role in producing 1e18~1e20 eV cosmic rays if SMNSs were formed in a good fraction of mergers and the merger rate is 1e3 yr^-1 Gpc^-3. S...

  5. Proposal of the Electrically Charged Stellar Black Holes as Accelerators of Ultra High Energy Cosmic Rays

    CERN Document Server

    Soto-Manriquez, Jose

    2016-01-01

    A new mechanism for the acceleration of ultra high energy cosmic rays (UHECR) is presented here. It is based on the tunnel-ionization of neutral atoms approaching electrically charged stellar black holes and on the repulsion of the resulting positively charged atomic part by huge, long-range electric fields. Energies above $10^{18}$ eV for these particles are calculated in a simple way by means of this single-shot, all-electrical model. When this acceleration mechanism is combined with the supernova explosions in the galactic halo of the massive runaway stars expelled from the galactic disk, this model predicts nearly the correct values of the measured top energy of the UHECRs and their flux in a specified EeV energy range. It also explains the near isotropy of the arrivals of these energetic particles to Earth, as has been recently measured by the Auger Observatory.

  6. Particle and astrophysical aspects of ultra-high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Sigl, G. [Observatoire de Paris, Section de Meudon (France). DARC]|[Chicago Univ., IL (United States). Dept. of Astronomy and Astrophysics

    2000-07-01

    The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the standard model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with {gamma}-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (orig.)

  7. Visualizing potential energy curves and conformations on ultra high-resolution display walls.

    Science.gov (United States)

    Kirschner, Karl N; Reith, Dirk; Jato, Oliver; Hinkenjann, André

    2015-11-01

    In this contribution, we examine how visualization on an ultra high-resolution display wall can augment force-field research in the field of molecular modeling. Accurate force fields are essential for producing reliable simulations, and subsequently important for several fields of applications (e.g. rational drug design and biomolecular modeling). We discuss how using HORNET, a recently constructed specific ultra high-resolution tiled display wall, enhances the visual analytics that are necessary for conformational-based interpretation of the raw data from molecular calculations. Simultaneously viewing multiple potential energy graphs and conformation overlays leads to an enhanced way of evaluating force fields and in their optimization. Consequently, we have integrated visual analytics into our existing Wolf2Pack workflow. We applied this workflow component to analyze how major AMBER force fields (Parm14SB, Gaff, Lipid14, Glycam06j) perform at reproducing the quantum mechanics relative energies and geometries of saturated hydrocarbons. Included in this comparison are the 1996 OPLS force field and our newly developed ExTrM force field. While we focus on atomistic force fields the ideas presented herein are generalizable to other research areas, particularly those that involve numerous representations of large data amounts and whose simultaneous visualization enhances the analysis.

  8. Energy gain and spectral tailoring of ion beams using ultra-high intensity laser beams

    Science.gov (United States)

    Prasad, Rajendra; Swantusch, Marco; Cerchez, Mirela; Spickermann, Sven; Auorand, Bastian; Wowra, Thomas; Boeker, Juergen; Willi, Oswald

    2015-11-01

    The field of laser driven ion acceleration over the past decade has produced a huge amount of research. Nowadays, several multi-beam facilities with high rep rate system, e.g. ELI, are being developed across the world for different kinds of experiments. The study of interaction dynamics of multiple beams possessing ultra-high intensity and ultra-short pulse duration is of vital importance. Here, we present the first experimental results on ion acceleration using two ultra-high intensity beams. Thanks to the unique capability of Arcturus laser at HHU Düsseldorf, two almost identical, independent beams in laser parameters such as intensity (>1020 W/cm2), pulse duration (30 fs) and contrast (>1010), could be accessed. Both beams are focused onto a 5 μm thin Ti target. While ensuring spatial overlap of the two beams, at relative temporal delay of ~ 50 ps (optimum delay), the proton and carbon ion energies were enhanced by factor of 1.5. Moreover, strong modulation in C4+ions near the high energy cut-off is observed later than the optimum delay for the proton enhancement. This offers controlled tailoring of the spectral content of heavy ions.

  9. Comparative energy consumption analyses of an ultra high frequency induction heating system for material processing applications

    Energy Technology Data Exchange (ETDEWEB)

    Tastan, M.; Gokozan, H.; Taskin, S.; Cavdar, U.

    2015-07-01

    This study compares an energy consumption results of the TI-6Al-4V based material processing under the 900 kHz induction heating for different cases. By this means, total power consumption and energy consumptions per sample and amount have been analyzed. Experiments have been conducted with 900 kHz, 2.8 kW ultra-high frequency induction system. Two cases are considered in the study. In the first case, TI-6Al-4V samples have been heated up to 900 degree centigrade with classical heating method, which is used in industrial applications, and then they have been cooled down by water. Afterwards, the samples have been heated up to 600 degree centigrade, 650 degree centigrade and 700 degree centigrade respectively and stress relieving process has been applied through natural cooling. During these processes, energy consumptions for each defined process have been measured. In the second case, unlike the first study, can be used five different samples have been heated up to the various temperatures between 600 degree centigrade and 1120 degree centigrade and energy consumptions have been measured for these processes. Thereby, the effect of temperature increase on each sample on energy cost has been analyzed. It has been seen that as a result of heating the titanium bulk materials, which have been used in the experiment, with ultra high frequency induction, temperature increase also increases the energy consumption. But it has been revealed that the increase rate in the energy consumption is more than the increase rate of the temperature. (Author)

  10. 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.

  11. Ultra high energy cosmic rays from non-relativistic quasar outflows

    CERN Document Server

    Wang, Xiawei

    2016-01-01

    It has been suggested that non-relativistic outflows from quasars can naturally account for the missing component of the extragalactic $\\gamma$-ray background and explain the cumulative neutrino background through pion decay in collisions between protons accelerated by the outflow shock and interstellar protons. Here we show that the same quasar outflows are capable of accelerating protons to energies of $\\sim 10^{20}$ eV during the early phase of their propagation. The overall quasar population is expected to produce a cumulative ultra high energy cosmic ray flux of $\\sim10^{-7}\\,\\rm GeV\\,cm^{-2}s^{-1}sr^{-1}$ at $E_{\\rm CR}\\gtrsim10^{18}$ eV. The spectral shape and amplitude is consistent with recent observations for outflow parameters constrained to fit secondary $\\gamma$-rays and neutrinos without any additional parameter tuning. This indicates that quasar outflows simultaneously account for all three messengers at their observed levels.

  12. HERMES: Simulating the Propagation of Ultra-High Energy Cosmic Rays

    CERN Document Server

    De Domenico, Manlio

    2013-01-01

    The study of ultra-high energy cosmic rays (UHECR) at Earth cannot prescind from the study of their propagation in the Universe. In this paper, we present HERMES, the \\emph{ad hoc} Monte Carlo code we have developed for the realistic simulation of UHECR propagation. We discuss the modeling adopted to simulate the cosmology, the magnetic fields, the interactions with relic photons and the production of secondary particles. In order to show the potential applications of HERMES for astroparticle studies, we provide an estimation of the surviving probability of UHE protons, the GZK horizons of nuclei and the all-particle spectrum observed at Earth in different astrophysical scenarios. Finally, we show the expected arrival direction distribution of UHECR produced from nearby candidate sources. A stable version of HERMES will be released in the next future for public use together with libraries of already propagated nuclei to allow the community to perform mass composition and energy spectrum analysis with our simu...

  13. Burst activity of the Crab Nebula and its pulsar at high and ultra-high energies

    Science.gov (United States)

    Lidvansky, A. S.

    2016-06-01

    Characteristics of the flares of gamma rays detected from the Crab Nebula by the AGILE and Fermi-LAT satellite instruments are compared with those of a gamma ray burst recorded by several air shower arrays on February 23, 1989 and with one recent observation made by ARGO-YBJ array. It is demonstrated that though pulsar-periodicity and energy spectra of emissions at 100 MeV (satellite gamma ray telescopes) and 100 TeV (EAS arrays) are different, their time structures seem to be similar. Moreover, may be the difference between "flares" and "waves" recently found in the Crab Nebula emission by AGILE team also exists at ultra-high energies.

  14. Testing the Correlation of Ultra-High Energy Cosmic Rays with High Redshift Sources

    CERN Document Server

    Sigl, G; Anchordoqui, L A; Romero, G; Sigl, Guenter; Torres, Diego; Anchordoqui, Luis; Romero, Gustavo

    2001-01-01

    We study the correlation between compact radio quasars and ultra-high energy cosmic rays using an updated list of air shower detections. We estimate the level of positional correlation between both samples and the probability of pure chance association through simulations of random sets of synthetic cosmic ray events. We find that there are no reasons to claim for a physical association and that some previous results appear to be an effect of the small size of the sample used. This is also true when, instead of compact radio quasars, 3EG gamma-ray blazars are considered. Consequently, unless somehow severely deflected, it is unlikely that the high energy CR primaries are new particles or particles with new interactions beyond the electroweak scale, produced in high-redshift active galactic nuclei.

  15. Searches for ultra-high energy neutrinos at the Pierre Auger observatory

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Muñiz, Jaime [Dept. Física de Partículas & Instituto Galego de Física de Altas Enerxías, Univ. de Santiago de Compostela (Spain); Observatorio Pierre Auger, Av. San Martín Norte 304, 5613 Malargüe (Argentina)

    2015-07-15

    Neutrinos in the sub-EeV energy range and above can be detected and identified with the Surface Detector array of the Pierre Auger Observatory. The identification can be efficiently done for neutrinos of all flavours interacting in the atmosphere, typically above 60° (downward-going), as well as for “Earth-skimming” neutrino interactions in the case of tau neutrinos (upward-going). Three sets of identification criteria were designed to search for downward-going neutrinos in the zenith angle bins 60° − 75° and 75° − 90° as well as for upward-going neutrinos. The three searches have been recently combined, providing, in the absence of candidates in data from 1 January 04 until 31 December 12, a stringent limit to the diffuse flux of ultra-high energy neutrinos.

  16. Ultra - High Energy Cosmic Rays from decay of the Super Heavy Dark Matter Relics

    CERN Document Server

    Doroshkevich, A G

    2000-01-01

    In this paper we briefly discuss the problem of the origin of Ultra High Energy Cosmic Rays in the framework of Top-Down models. We show that, for high energy of decays and in a wide range of spectra of injected protons, their extragalactic flux is consistent with the observed fluxes of cosmic rays in the energy range 0.1 E_{GZK}< E < 10E_{GZK}. For suitable energy and spectra of injected protons, the contribution of galactic sources is moderate, in this energy range, but it dominates at smaller and larger energies. In such models we can expect that at these energies the anisotropy of cosmic rays distribution over sky will be especially small. Some possible manifestations of decays of super massive particles such as, for example, primordial black holes with masses M_{pbh} ~ 10^{-5} g, are considered. In particular, we show that partial conversion of energy released during these decays at redshifts z ~ 1000 to Ly-alpha photons can delay the hydrogen recombination and distort the spectrum of fluctuations ...

  17. Development of acoustic devices for ultra-high energy neutrino detectors

    CERN Document Server

    Karg, T; Graf, K; Hoessl, J; Kappes, A; Katz, U; Lahmann, R; Naumann, C; Salomon, K; Schwemmer, S

    2005-01-01

    Acoustic neutrino detection is a promising approach to instrument the large detector volumes needed for the detection of the small neutrino fluxes expected at ultra-high energies (E > 1 EeV). We report on several studies investigating the feasibility of such an acoustic detector. High-precision lab measurements using laser and proton beams aiming at the verification of the thermo-acoustic model have been performed. Different types of acoustic sensors have been developed and characterized. An autonomous acoustic system, attached to the ANTARES prototype string "Line0", has been deployed and operated successfully at 2400 m depth, allowing for in-situ studies of the acoustic background in the Mediterranean Sea.

  18. Telescope Array Radar (TARA) observatory for Ultra-High Energy Cosmic Rays

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, R.; Othman, M. Abou Bakr [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Allen, C. [University of Kansas, Lawrence, KS 66045 (United States); Beard, L. [Purdue University, West Lafayette, IN 47907 (United States); Belz, J. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Besson, D. [University of Kansas, Lawrence, KS 66045 (United States); Moscow Engineering and Physics Institute, 31 Kashirskaya Shosse, Moscow 115409 (Russian Federation); Byrne, M.; Farhang-Boroujeny, B.; Gardner, A. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Gillman, W.H. [Gillman and Associates, Salt Lake City, UT 84106 (United States); Hanlon, W. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Hanson, J. [University of Kansas, Lawrence, KS 66045 (United States); Jayanthmurthy, C. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Kunwar, S. [University of Kansas, Lawrence, KS 66045 (United States); Larson, S.L. [Utah State University, Logan, Utah 84322 (United States); Myers, I., E-mail: isaac@cosmic.utah.edu [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Prohira, S.; Ratzlaff, K. [University of Kansas, Lawrence, KS 66045 (United States); Sokolsky, P. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Takai, H. [Brookhaven National Laboratory, Upton, NY 11973 (United States); and others

    2014-12-11

    Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

  19. Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope

    CERN Document Server

    Fujii, T; Bertaina, M; Casolino, M; Dawson, B; Horvath, P; Hrabovsky, M; Jiang, J; Mandat, D; Matalon, A; Matthews, J N; Motloch, P; Palatka, M; Pech, M; Privitera, P; Schovanek, P; Takizawa, Y; Thomas, S B; Travnicek, P; Yamazaki, K

    2015-01-01

    We present a concept for large-area, low-cost detection of ultra-high energy cosmic rays (UHECRs) with a Fluorescence detector Array of Single-pixel Tele- scopes (FAST), addressing the requirements for the next generation of UHECR experiments. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. We report first results of a FAST prototype installed at the Telescope Array site, consisting of a single 200 mm photomultiplier tube at the focal plane of a 1 m2 Fresnel lens system taken from the prototype of the JEM-EUSO experiment. The FAST prototype took data for 19 nights, demonstrating remarkable operational stability. We detected laser shots at distances of several kilometres as well as 16 highly significant UHECR shower candidates.

  20. Fluorescence resonance energy transfer of gas-phase ions under ultra high vacuum and ambient conditions.

    Science.gov (United States)

    Frankevich, Vladimir; Chagovets, Vitaliy; Widjaja, Fanny; Barylyuk, Konstantin; Yang, Zhiyi; Zenobi, Renato

    2014-05-21

    We report evidence for fluorescence resonance energy transfer (FRET) of gas-phase ions under ultra high vacuum conditions (10(-9) mbar) inside a mass spectrometer as well as under ambient conditions inside an electrospray plume. Two different FRET pairs based on carboxyrhodamine 6G (donor) and ATTO590 or Bodipy TR (acceptor) dyes were examined and their gas-phase optical properties were studied. Our measurements indicate a different behavior for the two FRET pairs, which can be attributed to their different conformations in the gas phase. Upon desolvation via electrospray ionization, one of the FRET pairs undergoes a conformational change that leads to disappearance of FRET. This study shows the promise of FRET to obtain a direct correlation between solution and gas-phase structures.

  1. Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

    CERN Document Server

    Abbasi, R; Allen, C; Beard, L; Belz, J; Besson, D; Byrne, M; Farhang-Boroujeny, B; Gardner, A; Gillman, W H; Hanlon, W; Hanson, J; Jayanthmurthy, C; Kunwar, S; Larson, S L; Myers, I; Prohyra, S; Ratzlaff, K; Sokolsky, P; Takai, H; Thomson, G B; Von Maluski, D

    2014-01-01

    Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest "conventional" cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs, extending their detection aperture far beyond what is accessible by conventional means. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

  2. The Role and Detectability of the Charm Contribution to Ultra High Energy Neutrino Fluxes

    CERN Document Server

    Gandhi, Raj; Watanabe, Atsushi

    2009-01-01

    It is widely believed that charm meson production and decay may play an important role in high energy astrophysical sources of neutrinos, especially those that are baryon-rich, providing an environment conducive to pp interactions. Using slow-jet supernovae (SJS) as an example of such a source, we study the detectability of high-energy neutrinos, paying particular attention to those produced from charmed-mesons. We highlight important distinguishing features in the ultra-high energy neutrino flux which would act as markers for the role of charm in the source. In particular, charm leads to significant event rates at higher energies, after the conventional (pi, K) neutrino fluxes fall off. We calculate event rates both for a nearby single source and for diffuse SJS fluxes for an IceCube-like detector. By comparing muon event rates for the conventional and prompt fluxes in different energy bins, we demonstrate the striking energy dependence in the rates induced by the presence of charm. We also show that it lead...

  3. Optimal radio window for the detection of ultra-high energy cosmic rays and neutrinos off the Moon

    NARCIS (Netherlands)

    Scholten, O.; Bacelar, J.; Braun, R.; de Bruyn, A. G.; Falcke, H.; Stappers, B.; Strom, R. G.

    2006-01-01

    When high-energy cosmic rays impinge on a dense dielectric medium, radio waves are produced through the Askaryan effect. We show that at wavelengths comparable to the length of the shower produced by an Ultra-High Energy cosmic ray or neutrino, radio signals are ail extremely efficient way to detect

  4. Recent Results on Ultra-High Energy Cosmic Rays from the Telescope Array

    CERN Document Server

    CERN. Geneva

    2015-01-01

    TA's recent results on Ultra-High Energy Cosmic Rays (UHECRs) are reported. The energy spectrum based on 20k events above 10^18.2 eV demonstrates a clear dip at 10^18.7 eV and a cutoff at 10^19.7 eV , the shape and the energies of which are well described by the GZK process: energy loss of extra-galactic protons by the interaction with the CMB and IR background. The primary composition obtained from the shower maximum analysis using the hybrid technique is consistent with 100% proton or light nuclei, and inconsistent with 100% iron up to 10^19.3 eV. Above the GZK cutoff energy, a large flux enhancement of medium size (radius=20deg) is observed in the direction of Ursa-Major. The chance probability of this hotspot appearing from the isotropic flux is 4.0sigma. The center of the hotspot is 19 deg off from the Super-Galactic Plane, and no obvious candidate of UHECRs is known in this direction.

  5. Detecting Local Deflection Patterns of Ultra-high Energy Cosmic Rays using the Principal Axes of the Directional Energy Distribution

    CERN Document Server

    Erdmann, Martin

    2013-01-01

    From deflections in galactic and extragalactic magnetic fields energy dependent structures in the arrival directions of ultra-high energy cosmic rays (UHECR) are expected. We propose to characterize these structures by the strength of collimation of energy along the principal axes in selected regions in the sky. While the strength of collimation are indicators of anisotropy in the arrival distribution of UHECR, the orientation of the principal system holds information about the direction of the deflections of UHECR. We discuss the method and present expected limits on the strength of deflection and density of sources using simulated scenarios of UHECR proton propagation.

  6. A strategy to unveil transient sources of ultra-high-energy cosmic rays

    Directory of Open Access Journals (Sweden)

    Takami Hajime

    2013-06-01

    Full Text Available Transient generation of ultra-high-energy cosmic rays (UHECRs has been motivated from promising candidates of UHECR sources such as gamma-ray bursts, flares of active galactic nuclei, and newly born neutron stars and magnetars. Here we propose a strategy to unveil transient sources of UHECRs from UHECR experiments. We demonstrate that the rate of UHECR bursts and/or flares is related to the apparent number density of UHECR sources, which is the number density estimated on the assumption of steady sources, and the time-profile spread of the bursts produced by cosmic magnetic fields. The apparent number density strongly depends on UHECR energies under a given rate of the bursts, which becomes observational evidence of transient sources. It is saturated at the number density of host galaxies of UHECR sources. We also derive constraints on the UHECR burst rate and/or energy budget of UHECRs per source as a function of the apparent source number density by using models of cosmic magnetic fields. In order to obtain a precise constraint of the UHECR burst rate, high event statistics above ∼ 1020 eV for evaluating the apparent source number density at the highest energies and better knowledge on cosmic magnetic fields by future observations and/or simulations to better estimate the time-profile spread of UHECR bursts are required. The estimated rate allows us to constrain transient UHECR sources by being compared with the occurrence rates of known energetic transient phenomena.

  7. Constraints on the source of ultra-high energy cosmic rays using anisotropy vs chemical composition

    CERN Document Server

    Liu, Ruo-Yu; Lemoine, Martin; Wang, Xiang-Yu; Waxman, Eli

    2013-01-01

    The joint analysis of anisotropy signals and chemical composition of ultra-high energy cosmic rays offers strong potential for shedding light on the sources of these particles. Following up on an earlier idea, this paper studies the anisotropies produced by protons of energy >E/Z, assuming that anisotropies at energy >E have been produced by nuclei of charge Z, which share the same magnetic rigidity. We calculate the number of secondary protons produced through photodisintegration of the primary heavy nuclei. Making the extreme assumption that the source does not inject any proton, we find that the source(s) responsible for anisotropies such as reported by the Pierre Auger Observatory should lie closer than ~20-30, 80-100 and 180-200 Mpc if the anisotropy signal is mainly composed of oxygen, silicon and iron nuclei respectively. A violation of this constraint would otherwise result in the secondary protons forming a more significant anisotropy signal at lower energies. Even if the source were located closer t...

  8. Are gamma-ray bursts the sources of ultra-high energy cosmic rays?

    CERN Document Server

    Baerwald, Philipp; Winter, Walter

    2014-01-01

    We reconsider the possibility that gamma-ray bursts (GRBs) are the sources of the ultra-high energy cosmic rays (UHECRs) within the internal shock model, assuming a pure proton composition of the UHECRs. For the first time, we combine the information from gamma-rays, cosmic rays, prompt neutrinos, and cosmogenic neutrinos quantitatively in a joint cosmic ray production and propagation model, and we show that the information on the cosmic energy budget can be obtained as a consequence. In addition to the neutron model, we consider alternative scenarios for the cosmic ray escape from the GRBs, i.e., that cosmic rays can leak from the sources. We find that the dip model, which describes the ankle in UHECR observations by the pair production dip, is strongly disfavored in combination with the internal shock model because a) unrealistically high baryonic loadings (energy in protons versus energy in electrons/gamma-rays) are needed for the individual GRBs and b) the prompt neutrino flux easily overshoots the corres...

  9. Graphene and carbon nanotube composite electrodes for supercapacitors with ultra-high energy density.

    Science.gov (United States)

    Cheng, Qian; Tang, Jie; Ma, Jun; Zhang, Han; Shinya, Norio; Qin, Lu-Chang

    2011-10-21

    We describe a graphene and single-walled carbon nanotube (SWCNT) composite film prepared by a blending process for use as electrodes in high energy density supercapacitors. Specific capacitances of 290.6 F g(-1) and 201.0 F g(-1) have been obtained for a single electrode in aqueous and organic electrolytes, respectively, using a more practical two-electrode testing system. In the organic electrolyte the energy density reached 62.8 Wh kg(-1) and the power density reached 58.5 kW kg(-1). The addition of single-walled carbon nanotubes raised the energy density by 23% and power density by 31% more than the graphene electrodes. The graphene/CNT electrodes exhibited an ultra-high energy density of 155.6 Wh kg(-1) in ionic liquid at room temperature. In addition, the specific capacitance increased by 29% after 1000 cycles in ionic liquid, indicating their excellent cyclicity. The SWCNTs acted as a conductive additive, spacer, and binder in the graphene/CNT supercapacitors. This work suggests that our graphene/CNT supercapacitors can be comparable to NiMH batteries in performance and are promising for applications in hybrid vehicles and electric vehicles.

  10. Search for Ultra High-Energy Neutrinos with AMANDA-II

    CERN Document Server

    Ackermann, M; Ahrens, J; Andeen, K; Auffenberg, J; Bai, X; Baret, B; Barwick, S W; Bay, R; Beattie, K; Becka, T; Becker, J K; Becker, K H; Beimforde, M; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Blaufuss, E; Boersma, D J; Bohm, C; Bolmont, J; Böser, S; Botner, O; Bouchta, A; Braun, J; Burgess, T; Castermans, T; Chirkin, D; Christy, B; Clem, J; Cowen, D F; D'Agostino, M V; Davour, A; Day, C T; De Clercq, C; Demirrs, L; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; De Young, T; Díaz-Veléz, J C; Dreyer, J; Dumm, J P; Duvoort, M R; Edwards, W R; Ehrlich, R; Eisch, J; Ellsworth, R W; Evenson, P A; Fadiran, O; Fazely, A R; Filimonov, K; Finley, C; Foerster, M M; Fox, B D; Franckowiak, A; Franke, R; Gaisser, T K; Gallagher, J; Ganugapati, R; Geenen, H; Gerhardt, L; Goldschmidt, A; Goodman, J A; Gozzini, R; Griesel, T; Gro, A; Grullon, S; Gunasingha, R M; Gurtner, M; Ha, C; Hallgren, A; Halzen, F; Han, K; Hanson, K; Hardtke, D; Hardtke, R; Hasegawa, Y; Hauschildt, T; Heise, J; Helbing, K; Hellwig, M; Herquet, P; Hill, G C; Hodges, J; Hoffman, K D; Hommez, B; Hoshina, K; Hubert, D; Hughey, B; Hul, J P; Hulth, P O; Hultqvist, K; Hundertmark, S; Inaba, M; Ishihara, A; Jacobsen, J; Japaridze, G S; Johansson, H; Joseph, J M; Kampert, K H; Kappes, A; Karg, T; Karle, A; Kawai, H; Kelley, J L; Kiryluk, J; Kislat, F; Kitamura, N; Klein, S R; Klepser, S; Kohnen, G; Kolanoski, H; Kpke, L; Kowalski, M; Kowarik, T; Krasberg, M; Kühn, K; Kuwabara, T; Labare, M; Laihem, K; Landsman, H; Lauer, R; Leich, H; Leier, D; Liubarsky, I; Lundberg, J; Lunemann, J; Madsen, J; Maruyama, R; Mase, K; Matis, H S; McCauley, T; McParland, C P; Meagher, K; Meli, A; Messarius, T; Mszros, P; Miyamoto, H; Montaruli, T; Mor, A; Morse, R; Movit, S M; Munich, K; Nahnhauer, R; Nam, J W; Nieen, P; Nygren, D R; Olivas, A; Ono, M; Patton, S; Prezdelos Heros, C; Piegsa, A; Pieloth, D; Pohl, A C; Porrata, R; Pretz, J; Price, P B; Przybylski, G T; Rawlins, K; Razzaque, S; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Rizzo, A; Robbins, S; Robbins, W J; Roth, P; Rothmaier, F; Rott, C; Roucelle, C; Rutledge, D; Ryckbosch, D; Sander, H G; Sarkar, S; Satalecka, K; Schlenstedt, S; Schmidt, T; Schneider, D; Schultz, O; Seckel, D; Semburg, B; Seo, S H; Sestayo, Y; Seunarine, S; Silvestri, A; Smith, A J; Song, C; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stezelberger, T; Stokstad, R G; Stoufer, M C; Stoyanov, S; Strahler, E A; Straszheim, T; Sulanke, K H; Sullivan, G W; Sumner, T J; Swillens, Q; Taboada, I; Tarasova; Tepe, A; Thollander, L; Tilav, S; Tluczykont, M; Toale, P A; Tosi, D; Turan, D; van Eijndhoven, N; Vandenbroucke, J; Van Overloop, A; Viscomi, V; Vogt, C; Voigt, B; Wagner, W; Walck, C; Waldmann, H; Waldenmaier, T; Walter, M; Wang, Y R; Wendt, C; Wiebusch, C H; Wiedemann, C; Wikstrm, G; Williams, D R; Wischnewski, R; Wissing, H; Woschnagg, K; Xu, X W; Yodh, G; Yoshida, S; De Dios-Zornoza-Gomez, Juan

    2007-01-01

    A search for diffuse neutrinos with energies in excess of 10^5 GeV is conducted with AMANDA-II data recorded between 2000 and 2002. Above 10^7 GeV, the Earth is essentially opaque to neutrinos. This fact, combined with the limited overburden of the AMANDA-II detector (roughly 1.5 km), concentrates these ultra high-energy neutrinos at the horizon. The primary background for this analysis is bundles of downgoing, high-energy muons from the interaction of cosmic rays in the atmosphere. No statistically significant excess above the expected background is seen in the data, and an upper limit is set on the diffuse all-flavor neutrino flux of E^{-2} $\\Phi$_{90%CL} < 2.7 $\\times$ 10^{-7} GeV cm^{-2} s^{-1} sr^{-1} valid over the energy range of 2 $\\times$ 10^5 GeV to 10^9 GeV. A number of models which predict neutrino fluxes from active galactic nuclei are excluded at the 90% confidence level.

  11. Propagation of Ultra High Energy Cosmic Rays in Extragalactic Magnetic Fields: A view from cosmological simulations

    CERN Document Server

    Hackstein, Stefan; Brueggen, Marcus; Sigl, Guenter; Dundovic, Andrej

    2016-01-01

    We use the CRPropa code to simulate the propagation of ultra high energy cosmic rays (with energy $\\geq 10^{18} \\rm eV$ and pure proton composition) through extragalactic magnetic fields that have been simulated with the cosmological ENZO code.We test both primordial and astrophysical magnetogenesis scenarios in order to investigate the impact of different magnetic field strengths in clusters, filaments and voids on the deflection of cosmic rays propagating across cosmological distances. We also study the effect of different source distributions of cosmic rays around simulated Milky-Way like observers. Our analysis shows that the arrival spectra and anisotropy of events are rather insensitive to the distribution of extragalactic magnetic fields, while they are more affected by the clustering of sources within a $\\sim 50$ Mpc distance to observers. Finally, we find that in order to reproduce the observed degree of isotropy of cosmic rays at $\\sim $ EeV energies, the average magnetic fields in cosmic voids must...

  12. Propagation of extragalactic photons at ultra-high energy with the EleCa code

    CERN Document Server

    Settimo, Mariangela

    2013-01-01

    Ultra-high energy (UHE) photons play an important role as an independent probe of the photo-pion production mechanism by UHE cosmic rays. Their observation, or non-observation, may constrain astrophysical scenarios for the origin of UHECRs and help to understand the nature of the flux suppression observed by several experiments at energies above $10^{19.5}$ eV. Whereas the interaction length of UHE photons above $10^{17}$ eV ranges from a few hundred kpc up to tenths of Mpc, photons can interact with the extragalactic background radiation initiating the development of electromagnetic cascades which affect the fluxes of photons observed at Earth. The interpretation of the current experimental results rely on the simulations of the UHE photon propagation. In this paper, we present the novel Monte Carlo code EleCa to simulate the $Ele$ctromagnetic $Ca$scading initiated by high-energy photons and electrons. We provide an estimation of the surviving probability for photons inducing electromagnetic cascades as a fu...

  13. HERMES: a Monte Carlo Code for the Propagation of Ultra-High Energy Nuclei

    CERN Document Server

    De Domenico, Manlio; Settimo, Mariangela

    2013-01-01

    Although the recent experimental efforts to improve the observation of Ultra-High Energy Cosmic Rays (UHECRs) above $10^{18}$ eV, the origin and the composition of such particles is still unknown. In this work, we present the novel Monte Carlo code (HERMES) simulating the propagation of UHE nuclei, in the energy range between $10^{16}$ and $10^{22}$ eV, accounting for propagation in the intervening extragalactic and Galactic magnetic fields and nuclear interactions with relic photons of the extragalactic background radiation. In order to show the potential applications of HERMES for astroparticle studies, we estimate the expected flux of UHE nuclei in different astrophysical scenarios, the GZK horizons and we show the expected arrival direction distributions in the presence of turbulent extragalactic magnetic fields. A stable version of HERMES will be released in the next future for public use together with libraries of already propagated nuclei to allow the community to perform mass composition and energy sp...

  14. A Measurement Of The Ultra-high Energy Cosmic Ray Flux With The Hires Fadc Detector

    CERN Document Server

    Zech, A

    2004-01-01

    We have measured the ultra-high energy cosmic ray flux with the newer one of the two detectors of the High Resolution Fly's Eye experiment (HiRes) in monocular mode. An outline of the HiRes experiment is given here, followed by a description of the trigger and Flash ADC electronics of the HiRes-2 detector. The computer simulation of the experiment, which is needed for resolution studies and the calculation of the detector acceptance, is presented in detail. Different characteristics of the simulated events are compared to real data to test the performance of the Monte Carlo simulation. The calculation of the energy spectrum is described, together with studies of systematic uncertainties due to the cosmic ray composition and aerosol content of the atmosphere that are assumed in the simulation. Data collected with the HiRes- 2 detector between December 1999 and September 2001 are included in the energy spectrum presented here. We compare our result with previous measurements by other experiments.

  15. Search for Anisotropy of Ultra-High Energy Cosmic Rays with the Telescope Array Experiment

    CERN Document Server

    Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Cheon, B G; Chiba, J; Chikawa, M; Cho, E J; Cho, W R; Fujii, H; Fujii, T; Fukuda, T; Fukushima, M; Hanlon, W; Hayashi, K; Hayashi, Y; Hayashida, N; Hibino, K; Hiyama, K; Honda, K; Iguchi, T; Ikeda, D; Ikuta, K; Inoue, N; Ishii, T; Ishimori, R; Ivanov, D; Iwamoto, S; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kanbe, T; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kido, E; Kim, H B; Kim, H K; Kim, J H; Kim, J H; Kitamoto, K; Kitamura, S; Kitamura, Y; Kobayashi, K; Kobayashi, Y; Kondo, Y; Kuramoto, K; Kuzmin, V; Kwon, Y J; Lim, S I; Machida, S; Martens, K; Martineau, J; Matsuda, T; Matsuura, T; Matsuyama, T; Matthews, J N; Minamino, M; Miyata, K; Murano, Y; Myers, I; Nagasawa, K; Nagataki, S; Nakamura, T; Nam, S W; Nonaka, T; Ogio, S; Ohnishi, M; Ohoka, H; Oki, K; Oku, D; Okuda, T; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Roh, S Y; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, J I; Shirahama, T; Smith, J D; Sokolsky, P; Sonley, T J; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T; Suzuki, S; Takahashi, Y; Takeda, M; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Tsuyuguchi, Y; Uchihori, Y; Udo, S; Ukai, H; Vasiloff, G; Wada, Y; Wong, T; Wood, M; Yamakawa, Y; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yoneda, Y; Yoshida, S; Yoshii, H; Zhou, X; Zollinger, R; Zundel, Z

    2012-01-01

    We study the anisotropy of Ultra-High Energy Cosmic Ray (UHECR) events collected by the Telescope Array (TA) detector in the first 40 months of operation. Following earlier studies, we examine event sets with energy thresholds of 10 EeV, 40 EeV, and 57 EeV. We find that the distributions of the events in right ascension and declination are compatible with an isotropic distribution in all three sets. We then compare with previously reported clustering of the UHECR events at small angular scales. No significant clustering is found in the TA data. We then check the events with E>57 EeV for correlations with nearby active galactic nuclei. No significant correlation is found. Finally, we examine all three sets for correlations with the large-scale structure of the Universe. We find that the two higher-energy sets are compatible with both an isotropic distribution and the hypothesis that UHECR sources follow the matter distribution of the Universe (the LSS hypothesis), while the event set with E>10 EeV is compatibl...

  16. Ultra-high energy neutrino fluxes as a probe for non-standard physics

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Atri; Choubey, Sandhya; Gandhi, Raj [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Watanabe, Atsushi, E-mail: atri@hri.res.in, E-mail: sandhya@hri.res.in, E-mail: nubarnu@gmail.com, E-mail: watanabe@muse.sc.niigata-u.ac.jp [Department of Physics, Niigata University, Niigata 950-2181 (Japan)

    2010-09-01

    We examine how light neutrinos coming from distant active galactic nuclei (AGN) and similar high energy sources may be used as tools to probe non-standard physics. In particular we discuss how studying the energy spectra of each neutrino flavour coming from such distant sources and their distortion relative to each other may serve as pointers to exotic physics such as neutrino decay, Lorentz symmetry violation, pseudo-Dirac effects, CP and CPT violation and quantum decoherence. This allows us to probe hitherto unexplored ranges of parameters for the above cases, for example lifetimes in the range 10{sup −3}−10{sup 4} s/eV for the case of neutrino decay. We show that standard neutrino oscillations ensure that the different flavours arrive at the earth with similar shapes even if their flavour spectra at source may differ strongly in both shape and magnitude. As a result, observed differences between the spectra of various flavours at the detector would be signatures of non-standard physics altering neutrino fluxes during propagation rather than those arising during their production at source. Since detection of ultra-high energy (UHE) neutrinos is perhaps imminent, it is possible that such differences in spectral shapes will be tested in neutrino detectors in the near future. To that end, using the IceCube detector as an example, we show how our results translate to observable shower and muon-track event rates.

  17. Predicted power in ultra high energy cosmic rays from active galaxies

    CERN Document Server

    Caramete, Laurentiu I; Biermann, Peter L; Stanev, Todor

    2011-01-01

    Context: As more and more data are collected by cosmic ray experiments such as the Pierre Auger Observatory and Telescope Array (TA), the search for the sources of the Ultra High Energy Cosmic Rays (UHECR) continues. Already we have some hints but no certain source or type of source is confirmed yet. Aims: We intend to predict the UHECR fluxes and the maximal energies of particles from two complete samples of nearby active galaxies, selected at radio and far-infrared frequencies. Also, we investigate the magnetic scattering of the UHECR path in the intervening cosmic space. Methods. We propose here a new method of searching for the sources of the UHECR in three steps, first we model the activity of the type of sources and get the flux of UHECR and a maximal energy for particle acceleration, then we model the interaction and angle deflection in the inter-galactic space and finally we get the distribution of the cosmic rays events that can be statistically compared with future data of the cosmic rays observator...

  18. Ultra-High-Energy Cosmic Rays from Low-Luminosity Active Galactic Nuclei

    CERN Document Server

    Dutan, Ioana

    2014-01-01

    We investigate the production of ultra-high-energy cosmic ray (UHECR) in relativistic jets from low-luminosity active galactic nuclei (LLAGN). We start by proposing a model for the UHECR contribution from the black holes (BHs) in LLAGN, which present a jet power $P_{\\mathrm{j}} \\leqslant 10^{46}$ erg s$^{-1}$. This is in contrast to the opinion that only high-luminosity AGN can accelerate particles to energies $ \\geqslant 50$ EeV. We rewrite the equations which describe the synchrotron self-absorbed emission of a non-thermal particle distribution to obtain the observed radio flux density from sources with a flat-spectrum core and its relationship to the jet power. We find that the UHECR flux is dependent on the {\\it observed radio flux density, the distance to the AGN, and the BH mass}, where the particle acceleration regions can be sustained by the magnetic energy extraction from the BH at the center of the AGN. We use a complete sample of 29 radio sources with a total flux density at 5 GHz greater than 0.5 ...

  19. Overview of lunar detection of ultra-high energy particles and new plans for the SKA

    Science.gov (United States)

    James, Clancy W.; Alvarez-Muñiz, Jaime; Bray, Justin D.; Buitink, Stijn; Dagkesamanskii, Rustam D.; Ekers, Ronald D.; Falcke, Heino; Gayley, Ken; Huege, Tim; Mevius, Maaijke; Mutel, Rob; Scholten, Olaf; Spencer, Ralph; ter Veen, Sander; Winchen, Tobias

    2017-03-01

    The lunar technique is a method for maximising the collection area for ultra-high-energy (UHE) cosmic ray and neutrino searches. The method uses either ground-based radio telescopes or lunar orbiters to search for Askaryan emission from particles cascading near the lunar surface. While experiments using the technique have made important advances in the detection of nanosecond-scale pulses, only at the very highest energies has the lunar technique achieved competitive limits. This is expected to change with the advent of the Square Kilometre Array (SKA), the low-frequency component of which (SKA-low) is predicted to be able to detect an unprecedented number of UHE cosmic rays. In this contribution, the status of lunar particle detection is reviewed, with particular attention paid to outstanding theoretical questions, and the technical challenges of using a giant radio array to search for nanosecond pulses. The activities of SKA's High Energy Cosmic Particles Focus Group are described, as is a roadmap by which this group plans to incorporate this detection mode into SKA-low observations. Estimates for the sensitivity of SKA-low phases 1 and 2 to UHE particles are given, along with the achievable science goals with each stage. Prospects for near-future observations with other instruments are also described.

  20. Ultra-High Energy Cosmic Particles studies from space: super-EUSO, a possible next-generation experiment

    CERN Document Server

    Petrolini, Alessandro

    2009-01-01

    After the Pierre Auger Observatory, it is likely that space-based experiments might be required for next-generation studies of Ultra-High Energy Cosmic Particles. An overview of this challenging task is presented, emphasizing the main design issues, the criticalities and the intermediate steps required to make this challenging task a reality.

  1. Optimized Trigger for Ultra-High-Energy Cosmic-Ray and Neutrino Observations with the Low Frequency Radio Array

    CERN Document Server

    Singh, K; Scholten, O; Anderson, J M; van Ardenne, A; Arts, M; Avruch, M; Asgekar, A; Bell, M; Bennema, P; Bentum, M; Bernadi, G; Best, P; Boonstra, A -J; Bregman, J; van de Brink, R; Broekema, C; Brouw, W; Brueggen, M; Buitink, S; Butcher, H; van Cappellen, W; Ciardi, B; Coolen, A; Damstra, S; Dettmar, R; van Diepen, G; Dijkstra, K; Donker, P; Doorduin, A; Drost, M; van Duin, A; Eisloeffel, J; Falcke, H; Garrett, M; Gerbers, M; Griessmeier, J; Grit, T; Gruppen, P; Gunst, A; van Haarlem, M; Hoeft, M; Holties, H; Horandel, J; Horneffer, L A; Huijgen, A; James, C; de Jong, A; Kant, D; Kooistra, E; Koopman, Y; Koopmans, L; Kuper, G; Lambropoulos, P; van Leeuwen, J; Loose, M; Maat, P; Mallary, C; McFadden, R; Meulman, H; Mol, J -D; Morawietz, J; Mulder, E; Munk, H; Nieuwenhuis, L; Nijboer, R; Norden, M; Noordam, J; Overeem, R; Paas, H; Pandey, V N; Pandey-Pommier, M; Pizzo, R; Polatidis, A; Reich, W; de Reijer, J; Renting, A; Riemers, P; Roettgering, H; Romein, J; Roosjen, J; Ruiter, M; Schoenmakers, A; Schoonderbeek, G; Sluman, J; Smirnov, O; Stappers, B; Steinmetz, M; Stiepel, H; Stuurwold, K; Tagger, M; Tang, Y; ter Veen, S; Vermeulen, R; de Vos, M; Vogt, C; van der Wal, E; Weggemans, H; Wijnholds, S; Wise, M; Wucknitz, O; Yattawatta, S; van Zwieten, J

    2011-01-01

    When an ultra-high energy neutrino or cosmic ray strikes the Lunar surface a radio-frequency pulse is emitted. We plan to use the LOFAR radio telescope to detect these pulses. In this work we propose an e?cient trigger implementation for LOFAR optimized for the observation of short radio pulses.

  2. Implications to Sources of Ultra-high-energy Cosmic Rays from their Arrival Distribution

    CERN Document Server

    Takami, Hajime

    2008-01-01

    We estimate the local number density of sources of ultra-high-energy cosmic rays (UHECRs) based on the statistical features of their arrival direction distribution. We calculate the arrival distributions of protons above $10^{19}$ eV taking into account their propagation process in the Galactic magnetic field and a structured intergalactic magnetic field, and statistically compare those with the observational result of the Pierre Auger Observatory. The anisotropy in the arrival distribution at the highest energies enables us to estimate the number density of UHECR sources as $\\sim 10^{-4} {\\rm Mpc}^{-3}$ assuming the persistent activity of UHECR sources. We compare the estimated number density of UHECR sources with the number densities of known astrophysical objects. This estimated number density is consistent with the number density of Fanaroff-Reily I galaxies. We also discuss the reproducability of the observed {\\it isotropy} in the arrival distribution above $10^{19}$ eV. We find that the estimated source...

  3. Planck-scale Lorentz violation constrained by ultra-high-energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Maccione, L. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Univ. Hamburg, II. Inst. fuer Theoretische Physik (Germany); Taylor, A.M. [Max-Planck-Inst. fuer Kernphysik, Heidelberg (Germany); Mattingly, D.M.; Liberati, S. [Scuola Internazionale Superiore di Studi Avanzati SISSA, Trieste (Italy); Istituto Nazionale di Fisica Nucleare INFN, Sezione di Trieste (Italy)

    2009-09-15

    We investigate the consequences of higher dimension Lorentz violating, CPT even kinetic operators that couple standard model fields to a non-zero vector field in an Effective Field Theory framework. Comparing the ultra-high energy cosmic ray spectrum reconstructed in the presence of such terms with data from the Pierre Auger observatory allows us to establish two sided bounds on the coefficients of the mass dimension five and six operators for the proton and pion. Our bounds imply that for both protons and pions, the energy scale of Lorentz symmetry breaking must be well above the Planck scale. In particular, the dimension five operators are constrained at the level of 10{sup -3}M{sup -1}{sub Planck}. The magnitude of the dimension six proton coefficient is bounded at the level of 10{sup -6}M{sup -2}{sub Planck} except in a narrow range where the pion and proton coefficients are both negative and nearly equal. In this small area, the magnitude of the dimension six proton coefficient must only be below 10{sup -3}M{sup -2}{sub Planck}. Constraints on the dimension six pion coefficient are found to be much weaker, but still below M{sup -2}{sub Planck}. (orig.)

  4. The Nature and Origin of Ultra-High Energy Cosmic Ray Particles

    CERN Document Server

    Biermann, Peter L; Fraschetti, Federico; Gergely, Laszlo A; Harms, Benjamin C; Kun, Emma; Lundquist, Jon Paul; Meli, Athina; Nath, Biman B; Seo, Eun-Suk; Stanev, Todor; Tjus, Julia Becker

    2016-01-01

    We outline two concepts to explain Ultra High Energy Cosmic Rays (UHECRs), one based on radio galaxies and their relativistic jets and terminal hot spots, and one based on relativistic Super-Novae (SNe) or Gamma Ray Bursts (GRBs) in starburst galaxies, one matching the arrival direction data in the South (the radio galaxy Cen A) and one in the North (the starburst galaxy M82). Ubiquitous neutrino emission follows accompanied by compact TeV photon emission, detectable more easily if the direction is towards Earth. The ejection of UHECRs is last. We have observed particles up to ZeV, neutrinos up to PeV, photons up to TeV, 30 - 300 Hz GW events, and hope to detect soon of order Hz to mHz GW events. Energy turnover in single low frequency GW events may be of order 10^63 erg. How can we further test these concepts? First of all by associating individual UHECR events, or directional groups of events, with chemical composition in both the Telescope Array (TA) Coll. and the Auger Coll. data. Second by identifying mo...

  5. A study of photons at ultra high energy using Auger surface detector

    CERN Document Server

    Decerprit, Guillaume; Parizot, E

    2016-01-01

    We present a new method to derive an upper limit on the ultra-high-energy (UHE) photon flux above a given energy, using the Auger SD events. As previous studies, it takes advantage of the fundamental differences between showers induced by hadrons and showers induced by photons (signal rise time, slope of the Lateral Distribution Function, radius of curvature), but it uses photon shower simulations adapted to the actually observed SD events, on an event-by-event basis. In particular, we find that a limited number of simulations per event allows to reach an upper limit that is very close to the ideal case that would be obtained with an infinite number of simulations. For instance, 10 simulated showers per event are sufficient to reach an upper limit only 10 percent higher than the ideal one. As an illustration, we apply this method to the SD events reconstructed above 55 EeV, which provides an optimized upper limit on the photon flux above 150 EeV, and indicate how this can be easily extended to the lower-energ...

  6. Lorentz invariance violation and chemical composition of ultra high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Saveliev, Andrey; Sigl, Guenter [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Maccione, Luca [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

    2010-12-15

    Motivated by experimental indications of a significant presence of heavy nuclei in the cosmic ray flux at ultra high energies (>or similar 10{sup 19} eV), we consider the effects of Planck scale suppressed Lorentz Invariance Violation (LIV) on the propagation of cosmic ray nuclei. In particular we focus on LIV effects on the photodisintegration of nuclei onto the background radiation fields. After a general discussion of the behavior of the relevant quantities, we apply our formalism to a simplified model where the LIV parameters of the various nuclei are assumed to kinematically result from a single LIV parameter for the constituent nucleons, {eta}, and we derive constraints on {eta}. Assuming a nucleus of a particular species to be actually present at 10{sup 20} eV the following constraints can be placed: -3 x 10{sup -2}

  7. Constraints on the Local Sources of Ultra High-Energy Cosmic Rays

    CERN Document Server

    Waxman, Eli

    2008-01-01

    Ultra high-energy cosmic rays (UHECRs) are believed to be protons accelerated in magnetized plasma outflows of extra-Galactic sources. The acceleration of protons to ~10^{20} eV requires a source power L>10^{47} erg/s. The absence of steady sources of sufficient power within the GZK horizon of 100 Mpc, implies that UHECR sources are transient. We show that UHECR "flares" should be accompanied by strong X-ray and gamma-ray emission, and that X-ray and gamma-ray surveys constrain flares which last less than a decade to satisfy at least one of the following conditions: (i) L>10^{50} erg/s; (ii) the power carried by accelerated electrons is lower by a factor >10^2 than the power carried by magnetic fields or by >10^3 than the power in accelerated protons; or (iii) the sources exist only at low redshifts, z10^{50} erg/s.

  8. Constraints on the flux of Ultra-High Energy neutrinos from WSRT observations

    Energy Technology Data Exchange (ETDEWEB)

    Scholten, O; Bacelar, J; Braun, R; de Bruyn, A G; Falcke, H; Singh, K; Stappers, B; Strom, R G; al Yahyaoui, R

    2010-04-02

    Context. Ultra-high energy (UHE) neutrinos and cosmic rays initiate particle cascades underneath the Moon's surface. These cascades have a negative charge excess and radiate Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequency window for observation of these pulses with radio telescopes on the Earth is around 150 MHz. Aims. By observing the Moon with the Westerbork Synthesis Radio Telescope array we are able to set a new limit on the UHEneutrino flux. Methods. The PuMa II backend is used to monitor the Moon in 4 frequency bands between 113 and 175 MHz with a sampling frequency of 40 MHz. The narrow band radio interference is digitally filtered out and the dispersive effect of the Earth?s ionosphere is compensated for. A trigger system is implemented to search for short pulses. By inserting simulated pulses in the raw data, the detection efficiency for pulses of various strength is calculated. Results. With 47.6 hours of observation time, we are able to set a limit on the UHE neutrino flux. This new limit is an order of magnitude lower than existing limits. In the near future, the digital radio array LOFAR will be used to achieve an even lower limit.

  9. Design of the Second-Generation ARIANNA Ultra-High-Energy Neutrino Detector Systems

    CERN Document Server

    ,

    2015-01-01

    We report on the development of the seven station ARIANNA Hexagonal Radio Array neutrino detector systems in Antarctica. The primary goal of the ARIANNA project is to observe ultra-high energy (>100 PeV) cosmogenic neutrino signatures using a large array of autonomous stations each dispersed 1 km apart on the surface of the Ross Ice Shelf. Sensing radio emissions of 100 MHz to 1 GHz, each station in the array contains RF antennas, amplifiers, a 2 G-sample/s signal acquisition and trigger circuit I.C. (the "SST"), an embedded CPU, 32 GB of solid-state data storage, a 20 Ah LiFePO4 battery with associated battery management unit, Iridium short-burst messaging satellite and long-distance WiFi communications. The new SST chip is completely synchronous, contains 4 channels of 256 samples per channel, obtains 6 orders of magnitude sample rate range up to 2 GHz acquisition speeds. It achieves 1.5 GHz bandwidth, 12 bits RMS of dynamic range, ~1 mV RMS trigger sensitivity at >600 MHz trigger bandwidth and ps-level tim...

  10. Constraints on the flux of Ultra-High Energy neutrinos from WSRT observations

    CERN Document Server

    Buitink, S; Bacelar, J; Braun, R; de Bruyn, A G; Falcke, H; Singh, K; Stappers, B; Strom, R G; Yahyaoui, R al

    2010-01-01

    Ultra-high energy (UHE) neutrinos and cosmic rays initiate particle cascades underneath the Moon's surface. These cascades have a negative charge excess and radiate Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequency window for observation of these pulses with radio telescopes on the Earth is around 150 MHz. By observing the Moon with the Westerbork Synthesis Radio Telescope array we are able to set a new limit on the UHE neutrino flux. The PuMa II backend is used to monitor the Moon in 4 frequency bands between 113 and 175 MHz with a sampling frequency of 40 MHz. The narrowband radio interference is digitally filtered out and the dispersive effect of the Earth's ionosphere is compensated for. A trigger system is implemented to search for short pulses. By inserting simulated pulses in the raw data, the detection efficiency for pulses of various strength is calculated. With 47.6 hours of observation time, we are able to set a limit on the UHE neutrino flux. This new limit ...

  11. Modeling a Kolmogorov-Type Magnetic Field in the Galaxy and its Effect on an Extragalactic Isotropic Flux of Ultra High Energy Cosmic Rays

    Science.gov (United States)

    Davoudifar, Pantea

    2016-08-01

    A model of turbulent galactic magnetic fields was developed in which, the type of turbulence were considered to be Kolmogorov. We tested the effect of this model on an isotropically distributed flux of ultra high energy cosmic ray in the extragalactic space. To do this, a giant Galactic halo (radius of ∼⃒ 100Mpc) was considered. Regular and random components of the Galactic Magnetic Fields were considered to have the mean observed relevant values and also satisfy a Kolmogorov field type. The deviation from isotropy then were calculated considering the propagation of ultra high energy protons in such a magnetic field and results were discussed to show how isotropic is the flux of ultra high energy cosmic rays in the extragalactic space. It is seen that considering an isotropic flux of ultra high energy cosmic rays in the intergalactic space for different choices of galactic magnetic field is not consistence with the distribution of observed ultra high energy events.

  12. EleCa: A Monte Carlo code for the propagation of extragalactic photons at ultra-high energy

    Energy Technology Data Exchange (ETDEWEB)

    Settimo, Mariangela [University of Siegen (Germany); De Domenico, Manlio [Laboratory of Complex Systems, Scuola Superiore di Catania and INFN (Italy); Lyberis, Haris [Federal University of Rio de Janeiro (Brazil)

    2013-06-15

    Ultra high energy photons, above 10{sup 17}–10{sup 18}eV, can interact with the extragalactic background radiation leading to the development of electromagnetic cascades. A Monte Carlo code to simulate the electromagnetic cascades initiated by high-energy photons and electrons is presented. Results from simulations and their impact on the predicted flux at Earth are discussed in different astrophysical scenarios.

  13. The sensitivity of past and near-future lunar radio experiments to ultra-high-energy cosmic rays and neutrinos

    CERN Document Server

    Bray, Justin

    2016-01-01

    Various experiments have been conducted to search for the radio emission from ultra-high-energy particles interacting in the lunar regolith. Although they have not yielded any detections, they have been successful in establishing upper limits on the flux of these particles. I present a review of these experiments in which I re-evaluate their sensitivity to radio pulses, accounting for effects which were neglected in the original reports, and compare them with prospective near-future experiments. In several cases, I find that past experiments were substantially less sensitive than previously believed. I apply existing analytic models to determine the resulting limits on the fluxes of ultra-high-energy neutrinos and cosmic rays. In the latter case, I amend the model to accurately reflect the fraction of the primary particle energy which manifests in the resulting particle cascade, resulting in a substantial improvement in the estimated sensitivity to cosmic rays. Although these models are in need of further ref...

  14. A Monte-Carlo simulation of the equilibrium beam polarization in ultra-high energy electron(positron) storage rings

    CERN Document Server

    Duan, Zhe; Barber, Desmond P; Qin, Qing

    2015-01-01

    With the recently emerging global interest in building a next generation of circular electron-positron colliders to study the properties of the Higgs boson, and other important topics in particle physics at ultra-high beam energies, it is also important to pursue the possibility of implementing polarized beams at this energy scale. It is therefore necessary to set up simulation tools to evaluate the beam polarization at these ultra-high beam energies. In this paper, a Monte-Carlo simulation of the equilibrium beam polarization based on the Polymorphic Tracking Code(PTC) is described. The simulations are for a model storage ring with parameters similar to those of proposed circular colliders in this energy range, and they are compared with the suggestion that there are different regimes for the spin dynamics underlying the polarization of a beam in the presence of synchrotron radiation at ultra-high beam energies. In particular, it has been suggested that the so-called "correlated" crossing of spin resonances ...

  15. On the Possible Association of Ultra High Energy Cosmic Rays with Nearby Active Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Moskalenko, Igor V.; Stawarz, Lukasz; Porter, Troy A.; Cheung, Chi C.

    2008-05-14

    Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of cosmic rays (CRs) with energies >57 EeV that suggests a correlation with the positions of active galactic nuclei (AGN) located within {approx}75 Mpc. However, this analysis does not take into account AGN morphology. A detailed study of the sample of AGN whose positions correlate with the CR events shows that most of them are classified as Seyfert 2 and low-ionization nuclear emission-line region (LINER) galaxies which do not differ from other local AGN of the same types. Therefore, the claimed correlation between the CR events observed by the Pierre Auger Observatory and local active galaxies should be considered as resulting from a chance coincidence, if the production of the highest energy CRs is not episodic in nature, but operates in a single object on long ({ge} Myr) timescales. Additionally, most of the selected sources do not show significant jet activity, and hence--in the framework of the jet paradigm--there are no reasons for expecting them to accelerate CRs up to the highest energies, {approx}10{sup 20} eV, at all. If the extragalactic magnetic fields and the sources of these CRs are coupled with matter, it is possible that the deflection angle is larger than expected in the case of a uniform source distribution due to effectively larger fields. A future analysis has to take into account AGN morphology and may yield a correlation with a larger deflection angle and/or more distant sources. We further argue that Cen A alone could be associated with at least 4 events due to its large radio extent, and Cen B can be associated with more than 1 event due to its proximity to the Galactic plane and, correspondingly, the stronger Galactic magnetic field the ultra high energy CRs (UHECRs) encounter during propagation. If the UHECRs associated with these events are indeed accelerated by Cen A and Cen B, their deflection angles may provide information on the

  16. Strong magnetic fields and SGRs/AXPs as white dwarf pulsar: a source of ultra-high energy cosmic rays

    Science.gov (United States)

    Lobato, Ronaldo V.; Malheiro, M.

    2016-04-01

    The origin of highest energy cosmic rays still remains a mystery in Astrophysics. In this work we consider the Soft Gamma Repeaters (SGRs) and Anomalous X-ray Pulsars (AXPs) as possible sources of ultra-high cosmic rays. These stars described as white dwarfs pulsars can achieved large electric potential differences in their surface and accelerate particles up to Lorentz factors γ ∼ 1010. Pulsars offer favorable sites for the injection of electrons and heavy nuclei, and accelerate them to ultrahigh energies. Once accelerated in the pulsar this particles can escape from the magnetosphere and produce the radiation observed. Here, we discuss the possibility of SGRs/AXPs as white dwarf pulsars to be possible sources of ultra-high energetic photons with E ∼ 1021eV.

  17. Origin of the ankle in the ultra-high energy cosmic ray spectrum and of the extragalactic protons below it

    CERN Document Server

    Farrar, Glennys R; Anchordoqui, Luis A

    2015-01-01

    The sharp change in slope of the ultra-high energy cosmic ray (UHECR) spectrum around 10^{18.6} eV (the ankle), combined with evidence of a light but extragalactic component near and below the ankle which evolves to intermediate composition above, has proved exceedingly challenging to understand theoretically. We show that for a range of source conditions, photo-disintegration of ultra-high energy nuclei in the region surrounding a UHECR accelerator naturally accounts for the observed spectrum and composition of the entire extragalactic component, which dominates above about 10^{17.5} eV. The mechanism has a clear signature in the spectrum and flavors of neutrinos.

  18. Probing physics at extreme energies with cosmic ultra-high energy radiation

    Indian Academy of Sciences (India)

    Günter Sigl

    2003-02-01

    The highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the standard model (SM) and processes taking place at the earliest moments of our universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with -ray and neutrino astrophysics will put strong constraints on these theoretical models. We give an overview over this quickly evolving research field with focus on testing new particle physics.

  19. Energy and Flux Measurements of Ultra-High Energy Cosmic Rays Observed During the First ANITA Flight

    CERN Document Server

    Schoorlemmer, H; Romero-Wolf, A; García-Fernández, D; Bugaev, V; Wissel, S A; Allison, P; Alvarez-Muñiz, J; Barwick, S W; Beatty, J J; Besson, D Z; Binns, W R; Carvalho, W R; Chen, C; Chen, P; Clem, J M; Connolly, A; Dowkontt, P F; DuVernois, M A; Field, R C; Goldstein, D; Gorham, P W; Hast, C; Heber, C L; Huege, T; Hoover, S; Israel, M H; Javaid, A; Kowalski, J; Lam, J; Learned, J G; Liewer, K M; Link, J T; Lusczek, E; Matsuno, S; Mercurio, B C; Miki, C; Miočinović, P; Mulrey, K; Nam, J; Naudet, C J; Ng, J; Nichol, R J; Palladino, K; Rauch, B F; Roberts, J; Reil, K; Rotter, B; Rosen, M; Ruckman, L; Saltzberg, D; Seckel, D; Urdaneta, D; Varner, G S; Vieregg, A G; Walz, D; Wu, F; Zas, E

    2015-01-01

    The first flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment recorded 16 radio signals that were emitted by cosmic-ray induced air showers. For 14 of these events, this radiation was reflected from the ice. The dominant contribution to the radiation from the deflection of positrons and electrons in the geomagnetic field, which is beamed in the direction of motion of the air shower. This radiation is reflected from the ice and subsequently detected by the ANITA experiment at a flight altitude of 36km. In this paper, we estimate the energy of the 14 individual events and find that the mean energy of the cosmic-ray sample is 2.9 EeV. By simulating the ANITA flight, we calculate its exposure for ultra-high energy cosmic rays. We estimate for the first time the cosmic-ray flux derived only from radio observations. In addition, we find that the Monte Carlo simulation of the ANITA data set is in agreement with the total number of observed events and with the properties of those events.

  20. Optimal Radio Window for the Detection of Ultra-High-Energy Cosmic Rays and Neutrinos off the Moon

    CERN Document Server

    Scholten, O; Braun, R; De Bruyn, A G; Falcke, H; Stappers, B; Strom, R G

    2006-01-01

    We show that at wavelengths comparable to the length of the shower produced by an Ultra-High Energy cosmic ray or neutrino, radio signals are an extremely efficient way to detect these particles. Through an example it is shown that this new approach offers, for the first time, the realistic possibility of measuring UHE neutrino fluxes below the Waxman-Bahcall limit. It is shown that in only one month of observing with the upcoming LOFAR radio telescope, cosmic-ray events can be measured beyond the GZK-limit, at a sensitivity level of two orders of magnitude below the extrapolated values.

  1. Ultra-high Energy Cosmic Rays and Neutrinos from Gamma-Ray Bursts, Hypernovae and Galactic Shocks

    CERN Document Server

    Mészáros, P

    2014-01-01

    I review gamma-ray burst models (GRBs) and observations, and discuss the possible production of ultra-high energy cosmic rays and neutrinos in both the standard internal shock models and the newer generation of photospheric and hadronic GRB models, in the light of current constraints imposed by IceCube, Auger and TA observations. I then discuss models that have been proposed to explain the recent astrophysical PeV neutrino observations, including star-forming and star-burst galaxies, hypernovae and galaxy accretion and merger shocks.

  2. Performance of two Askaryan Radio Array stations and first results in the search for ultra-high energy neutrinos

    CERN Document Server

    Allison, P; Beatty, J J; Besson, D Z; Bora, C; Chen, C -C; Chen, C -H; Chen, P; Christenson, A; Connolly, A; Davies, J; Duvernois, M; Fox, B; Gaior, R; Gorham, P W; Hanson, K; Haugen, J; Hill, B; Hoffman, K D; Hong, E; Hsu, S -Y; Hu, L; Huang, J -J; Huang, M -H A; Ishihara, A; Karle, A; Kelley, J L; Kennedy, D; Kravchenko, I; Kuwabara, T; Landsman, H; Laundrie, A; Li, C -J; Liu, T C; Lu, M -Y; Macchiarulo, L; Mase, K; Meures, T; Meyhandan, R; Miki, C; Morse, R; Nam, J; Nichol, R J; Nir, G; Novikov, A; Pfendner, C; Ratzlaff, K; Relich, M; Richman, M; Ritter, L; Rotter, B; Sandstrom, P; Schellin, P; Shultz, A; Seckel, D; Shiao, Y -S; Stockham, J; Stockham, M; Touart, J; Varner, G S; Wang, M -Z; Wang, S -H; Yang, Y; Yoshida, S; Young, R

    2015-01-01

    Ultra-high energy neutrinos are interesting messenger particles since, if detected, they can transmit exclusive information about ultra-high energy processes in the Universe. These particles, with energies above $10^{16}\\mathrm{eV}$, interact very rarely. Therefore, detectors that instrument several gigatons of matter are needed to discover them. The ARA detector is currently being constructed at South Pole. It is designed to use the Askaryan effect, the emission of radio waves from neutrino-induced cascades in the South Pole ice, to detect neutrino interactions at very high energies. With antennas distributed among 37 widely-separated stations in the ice, such interactions can be observed in a volume of several hundred cubic kilometers. Currently 3 deep ARA stations are deployed in the ice of which two have been taking data since the beginning of the year 2013. In this publication, the ARA detector "as-built" and calibrations are described. Furthermore, the data reduction methods used to distinguish the rare...

  3. An improved limit to the diffuse flux of ultra-high energy neutrinos from the Pierre Auger Observatory

    CERN Document Server

    Aab, Alexander; Aglietta, Marco; Ahn, Eun-Joo; Samarai, Imen Al; Albuquerque, Ivone; Allekotte, Ingomar; Allison, Patrick; Almela, Alejandro; Castillo, Jesus Alvarez; Alvarez-Muñiz, Jaime; Batista, Rafael Alves; Ambrosio, Michelangelo; Aminaei, Amin; Anchordoqui, Luis; Andringa, Sofia; Aramo, Carla; Aranda, Victor Manuel; Arqueros, Fernando; Arsene, Nicusor; Asorey, Hernán Gonzalo; Assis, Pedro; Aublin, Julien; Ave, Maximo; Avenier, Michel; Avila, Gualberto; Awal, Nafiun; Badescu, Alina Mihaela; Barber, Kerri B; Bäuml, Julia; Baus, Colin; Beatty, Jim; Becker, Karl Heinz; Bellido, Jose A; Berat, Corinne; Bertaina, Mario Edoardo; Bertou, Xavier; Biermann, Peter; Billoir, Pierre; Blaess, Simon G; Blanco, Alberto; Blanco, Miguel; Bleve, Carla; Blümer, Hans; Boháčová, Martina; Boncioli, Denise; Bonifazi, Carla; Borodai, Nataliia; Brack, Jeffrey; Brancus, Iliana; Bridgeman, Ariel; Brogueira, Pedro; Brown, William C; Buchholz, Peter; Bueno, Antonio; Buitink, Stijn; Buscemi, Mario; Caballero-Mora, Karen S; Caccianiga, Barbara; Caccianiga, Lorenzo; Candusso, Marina; Caramete, Laurentiu; Caruso, Rossella; Castellina, Antonella; Cataldi, Gabriella; Cazon, Lorenzo; Cester, Rosanna; Chavez, Alan G; Chiavassa, Andrea; Chinellato, Jose Augusto; Chudoba, Jiri; Cilmo, Marco; Clay, Roger W; Cocciolo, Giuseppe; Colalillo, Roberta; Coleman, Alan; Collica, Laura; Coluccia, Maria Rita; Conceição, Ruben; Contreras, Fernando; Cooper, Mathew J; Cordier, Alain; Coutu, Stephane; Covault, Corbin; Cronin, James; Dallier, Richard; Daniel, Bruno; Dasso, Sergio; Daumiller, Kai; Dawson, Bruce R; de Almeida, Rogerio M; de Jong, Sijbrand J; De Mauro, Giuseppe; Neto, Joao de Mello; De Mitri, Ivan; de Oliveira, Jaime; de Souza, Vitor; del Peral, Luis; Deligny, Olivier; Dembinski, Hans; Dhital, Niraj; Di Giulio, Claudio; Di Matteo, Armando; Diaz, Johana Chirinos; Castro, Mary Lucia Díaz; Diogo, Francisco; Dobrigkeit, Carola; Docters, Wendy; D'Olivo, Juan Carlos; Dorofeev, Alexei; Hasankiadeh, Qader Dorosti; Dova, Maria Teresa; Ebr, Jan; Engel, Ralph; Erdmann, Martin; Erfani, Mona; Escobar, Carlos O; Espadanal, Joao; Etchegoyen, Alberto; Falcke, Heino; Fang, Ke; Farrar, Glennys; Fauth, Anderson; Fazzini, Norberto; Ferguson, Andrew P; Fernandes, Mateus; Fick, Brian; Figueira, Juan Manuel; Filevich, Alberto; Filipčič, Andrej; Fox, Brendan; Fratu, Octavian; Freire, Martín Miguel; Fuchs, Benjamin; Fujii, Toshihiro; García, Beatriz; Garcia-Pinto, Diego; Gate, Florian; Gemmeke, Hartmut; Gherghel-Lascu, Alexandru; Ghia, Piera Luisa; Giaccari, Ugo; Giammarchi, Marco; Giller, Maria; Głas, Dariusz; Glaser, Christian; Glass, Henry; Golup, Geraldina; Berisso, Mariano Gómez; Vitale, Primo F Gómez; González, Nicolás; Gookin, Ben; Gordon, Jacob; Gorgi, Alessio; Gorham, Peter; Gouffon, Philippe; Griffith, Nathan; Grillo, Aurelio; Grubb, Trent D; Guardincerri, Yann; Guarino, Fausto; Guedes, Germano; Hampel, Matías Rolf; Hansen, Patricia; Harari, Diego; Harrison, Thomas A; Hartmann, Sebastian; Harton, John; Haungs, Andreas; Hebbeker, Thomas; Heck, Dieter; Heimann, Philipp; Herve, Alexander E; Hill, Gary C; Hojvat, Carlos; Hollon, Nicholas; Holt, Ewa; Homola, Piotr; Hörandel, Jörg; Horvath, Pavel; Hrabovský, Miroslav; Huber, Daniel; Huege, Tim; Insolia, Antonio; Isar, Paula Gina; Jandt, Ingolf; Jansen, Stefan; Jarne, Cecilia; Johnsen, Jeffrey A; Josebachuili, Mariela; Kääpä, Alex; Kambeitz, Olga; Kampert, Karl Heinz; Kasper, Peter; Katkov, Igor; Kégl, Balazs; Keilhauer, Bianca; Keivani, Azadeh; Kemp, Ernesto; Kieckhafer, Roger; Klages, Hans; Kleifges, Matthias; Kleinfeller, Jonny; Krause, Raphael; Krohm, Nicole; Krömer, Oliver; Kuempel, Daniel; Kunka, Norbert; LaHurd, Danielle; Latronico, Luca; Lauer, Robert; Lauscher, Markus; Lautridou, Pascal; Coz, Sandra Le; Lebrun, Didier; Lebrun, Paul; de Oliveira, Marcelo Augusto Leigui; Letessier-Selvon, Antoine; Lhenry-Yvon, Isabelle; Link, Katrin; Lopes, Luis; López, Rebeca; Casado, Aida López; Louedec, Karim; Lu, Lu; Lucero, Agustin; Malacari, Max; Maldera, Simone; Mallamaci, Manuela; Maller, Jennifer; Mandat, Dusan; Mantsch, Paul; Mariazzi, Analisa; Marin, Vincent; Mariş, Ioana; Marsella, Giovanni; Martello, Daniele; Martin, Lilian; Martinez, Humberto; Bravo, Oscar Martínez; Martraire, Diane; Meza, Jimmy Masías; Mathes, Hermann-Josef; Mathys, Sebastian; Matthews, James; Matthews, John; Matthiae, Giorgio; Maurel, Detlef; Maurizio, Daniela; Mayotte, Eric; Mazur, Peter; Medina, Carlos; Medina-Tanco, Gustavo; Meissner, Rebecca; Mello, Victor; Melo, Diego; Menshikov, Alexander; Messina, Stefano; Meyhandan, Rishi; Micheletti, Maria Isabel; Middendorf, Lukas; Minaya, Ignacio A; Miramonti, Lino; Mitrica, Bogdan; Molina-Bueno, Laura; Mollerach, Silvia; Montanet, François; Morello, Carlo; Mostafá, Miguel; Moura, Celio A; Muller, Marcio Aparecido; Müller, Gero; Müller, Sarah; Mussa, Roberto; Navarra, Gianni; Navarro, Jose Luis; Navas, Sergio; Necesal, Petr; Nellen, Lukas; Nelles, Anna; Neuser, Jens; Nguyen, Phong H; Niculescu-Oglinzanu, Mihai; Niechciol, Marcus; Niemietz, Lukas; Niggemann, Tim; Nitz, Dave; Nosek, Dalibor; Novotny, Vladimir; Nožka, Lyberis; Ochilo, Livingstone; Oikonomou, Foteini; Olinto, Angela; Pacheco, Noelia; Selmi-Dei, Daniel Pakk; Palatka, Miroslav; Pallotta, Juan; Papenbreer, Philipp; Parente, Gonzalo; Parra, Alejandra; Paul, Thomas; Pech, Miroslav; Pękala, Jan; Pelayo, Rodrigo; Pepe, Iuri; Perrone, Lorenzo; Petermann, Emily; Peters, Christine; Petrera, Sergio; Petrov, Yevgeniy; Phuntsok, Jamyang; Piegaia, Ricardo; Pierog, Tanguy; Pieroni, Pablo; Pimenta, Mário; Pirronello, Valerio; Platino, Manuel; Plum, Matthias; Porcelli, Alessio; Porowski, Czeslaw; Prado, Raul Ribeiro; Privitera, Paolo; Prouza, Michael; Purrello, Victor; Quel, Eduardo J; Querchfeld, Sven; Quinn, Sean; Rautenberg, Julian; Ravel, Olivier; Ravignani, Diego; Revenu, Benoît; Ridky, Jan; Riggi, Simone; Risse, Markus; Ristori, Pablo; Rizi, Vincenzo; de Carvalho, Washington Rodrigues; Fernandez, Gonzalo Rodriguez; Rojo, Jorge Rubén Rodriguez; Rodríguez-Frías, Maria Dolores; Rogozin, Dmytro; Rosado, Jaime; Roth, Markus; Roulet, Esteban; Rovero, Adrian; Saffi, Steven J; Saftoiu, Alexandra; Salamida, Francesco; Salazar, Humberto; Saleh, Ahmed; Greus, Francisco Salesa; Salina, Gaetano; Sánchez, Federico; Sanchez-Lucas, Patricia; Santos, Edivaldo Moura; Santos, Eva; Sarazin, Fred; Sarkar, Biswaijt; Sarmento, Raul; Sato, Ricardo; Scarso, Carlos; Schauer, Markus; Scherini, Viviana; Schieler, Harald; Schiffer, Peter; Schmidt, David; Scholten, Olaf; Schoorlemmer, Harm; Schovánek, Petr; Schröder, Frank G; Schulz, Alexander; Schulz, Johannes; Schumacher, Johannes; Sciutto, Sergio; Segreto, Alberto; Settimo, Mariangela; Shadkam, Amir; Shellard, Ronald C; Sidelnik, Iván; Sigl, Guenter; Sima, Octavian; Śmiałkowski, Andrzej; Šmída, Radomir; Snow, Gregory; Sommers, Paul; Sorokin, J; Squartini, Ruben; Srivastava, Yogendra N; Stanca, Denis; Stanič, Samo; Stapleton, James; Stasielak, Jaroslaw; Stephan, Maurice; Stutz, Anne; Suarez, Federico; Suomijärvi, Tiina; Supanitsky, A Daniel; Sutherland, Michael; Swain, John; Szadkowski, Zbigniew; Taborda, Oscar Alejandro; Tapia, Alex; Tepe, Andreas; Theodoro, Vanessa Menezes; Tiffenberg, Javier; Timmermans, Charles; Peixoto, Carlos J Todero; Toma, Gabriel; Tomankova, Lenka; Tomé, Bernardo; Tonachini, Aurelio; Elipe, Guillermo Torralba; Machado, Diego Torres; Travnicek, Petr; Ulrich, Ralf; Unger, Michael; Urban, Martin; Galicia, Jose F Valdés; Valiño, Ines; Valore, Laura; van Aar, Guus; van Bodegom, Patrick; Berg, Ad M van den; van Velzen, Sjoert; van Vliet, Arjen; Varela, Enrique; Cárdenas, Bernardo Vargas; Varner, Gary; Vasquez, Rafael; Vázquez, Jose R; Vázquez, Ricardo; Veberič, Darko; Verzi, Valerio; Vicha, Jakub; Videla, Mariela; Villaseñor, Luis; Vlcek, Brian; Vorobiov, Serguei; Wahlberg, Hernan; Wainberg, Oscar; Walz, David; Watson, Alan; Weber, Marc; Weidenhaupt, Klaus; Weindl, Andreas; Werner, Felix; Widom, Allan; Wiencke, Lawrence; Wilczyński, Henryk; Winchen, Tobias; Wittkowski, David; Wundheiler, Brian; Wykes, Sarka; Yang, Lili; Yapici, Tolga; Yushkov, Alexey; Zas, Enrique; Zavrtanik, Danilo; Zavrtanik, Marko; Zepeda, Arnulfo; Zhu, Yue; Zimmermann, Benedikt; Ziolkowski, Michael; Zuccarello, Francesca

    2015-01-01

    Neutrinos in the cosmic ray flux with energies near 1 EeV and above are detectable with the Surface Detector array of the Pierre Auger Observatory. We report here on searches through Auger data from 1 January 2004 until 20 June 2013. No neutrino candidates were found, yielding a limit to the diffuse flux of ultra-high energy neutrinos that challenges the Waxman-Bahcall bound predictions. Neutrino identification is attempted using the broad time-structure of the signals expected in the SD stations, and is efficiently done for neutrinos of all flavors interacting in the atmosphere at large zenith angles, as well as for "Earth-skimming" neutrino interactions in the case of tau neutrinos. In this paper the searches for downward-going neutrinos in the zenith angle bins $60^\\circ-75^\\circ$ and $75^\\circ-90^\\circ$ as well as for upward-going neutrinos, are combined to give a single limit. The $90\\%$ C.L. single-flavor limit to the diffuse flux of ultra-high energy neutrinos with an $E^{-2}$ spectrum in the energy ra...

  4. Capability of the HAWC gamma-ray observatory for the indirect detection of ultra-high energy neutrinos

    CERN Document Server

    Vargas, Hermes León; Belmont, Ernesto; Alfaro, Rubén

    2016-01-01

    The detection of ultra-high energy neutrinos, with energies in the PeV range or above, is a topic of great interest in modern astroparticle physics. The importance comes from the fact that these neutrinos point back to the most energetic particle accelerators in the Universe, and provide information about their underlying acceleration mechanisms. Atmospheric neutrinos are a background for these challenging measurements, but their rate is expected to be negligible above $\\approx$ 1 PeV. In this work we describe the feasibility to study ultra-high energy neutrinos based on the Earth-skimming technique, by detecting the charged leptons produced in neutrino-nucleon interactions in a high mass target. We propose to detect the charged leptons, or their decay products, with the recently inaugurated High Altitude Water Cherenkov (HAWC) observatory, and use as a large mass target for the neutrino interactions the Pico de Orizaba volcano, the highest mountain in Mexico. In this work we develop an estimate of the detect...

  5. Reconstruction of Longitudinal Profiles of Ultra-High Energy Cosmic Ray Showers from Fluorescence and Cherenkov Light Measurements

    CERN Document Server

    Unger, M; Engel, R; Schüssler, F; Ulrich, R

    2008-01-01

    We present a new method for the reconstruction of the longitudinal profile of extensive air showers induced by ultra-high energy cosmic rays. In contrast to the typically considered shower size profile, this method employs directly the ionization energy deposit of the shower particles in the atmosphere. Due to universality of the energy spectra of electrons and positrons, both fluorescence and Cherenkov light can be used simultaneously as signal to infer the shower profile from the detected light. The method is based on an analytic least-square solution for the estimation of the shower profile from the observed light signal. Furthermore, the extrapolation of the observed part of the profile with a Gaisser-Hillas function is discussed and the total statistical uncertainty of shower parameters like total energy and shower maximum is calculated.

  6. Blazars as Ultra-High-Energy Cosmic-Ray Sources: Implications for TeV Gamma-Ray Observations

    CERN Document Server

    Murase, Kohta; Takami, Hajime; Migliori, Giulia

    2011-01-01

    Spectral fitting of correlated multiwavelength data of BL Lac objects and Fanaroff-Riley I radio galaxies gives the mean comoving magnetic field strength B', the bulk outflow Doppler factor Gamma, and the emission region size R' of the radiating plasma in the one-zone leptonic synchrotron self-Compton (SSC) model. From the Hillas condition, we show that only in rare cases can these sources accelerate protons to much above 10^19 eV, so >10^20 eV ultra-high-energy cosmic rays are likely to be heavy ions if powered by this type of AGN. One of the signatures of hadronic production by blazars is intergalactic cascade emission initiated by ultra-high-energy cosmic rays, which can explain TeV spectra of some extreme, apparently non-variable blazars such as 1ES 0229+200. We study this kind of cascade signal from such blazars, taking into account effects of the structured extragalactic magnetic fields in clusters and filaments in which the blazars are embedded. We demonstrate the importance of cosmic-ray deflections o...

  7. Measurement of the chemical composition of the ultra-high-energy cosmic rays with the Pierre Auger Observatory

    CERN Document Server

    Plum, Matthias

    2013-01-01

    The Pierre Auger Observatory infers the chemical composition of ultra-high-energy cosmic rays through two independent detection techniques. The Fluorescence Detector (FD) measures the longitudinal profile of high energy air showers and can determine the depth of the shower maximum $X_{max}$, which is sensitive to the chemical composition of the primary cosmic rays. Additionally, measurements by the Surface Detector (SD) provide independent experimental observables based on the muonic shower component to analyze the chemical composition. We present the results for the $X_{max}$ distributions and the mass composition results measured by the FD and the SD for the energies $E \\geq 10^{18}$\\,eV. The data will be compared with the expectations for proton and iron primaries according to different hadronic interaction models.

  8. Measurement of the mass composition of ultra-high energy cosmic rays with the Pierre Auger Observatory

    Science.gov (United States)

    Settimo, Mariangela; Pierre Auger Collaboration

    2016-05-01

    The understanding of the nature of ultra-high energy cosmic rays is one of the most intriguing open questions for current and future observatories. With its hybrid design and huge exposure, the Pierre Auger Observatory provides valuable statistical measurements of the chemical composition of cosmic rays with energies above 1017 eV, including the search for neutral primaries such as neutrinos and photons. We report on the most recent results which are based on the accurate measurement of the depth of the shower maximum, Xmax, by the fluorescence telescopes and on the shape of the signals recorded by the water-Cherenkov detectors. The interpretation of these results in terms of mass composition is also discussed related to the hadronic interaction models used to describe the development of air showers.

  9. A limit on the ultra-high-energy neutrino flux from lunar observations with the Parkes radio telescope

    CERN Document Server

    Bray, J D; Roberts, P; Reynolds, J E; James, C W; Phillips, C J; Protheroe, R J; McFadden, R A; Aartsen, M G

    2015-01-01

    We report a limit on the ultra-high-energy neutrino flux based on a non-detection of radio pulses from neutrino-initiated particle cascades in the Moon, in observations with the Parkes radio telescope undertaken as part of the LUNASKA project. Due to the improved sensitivity of these observations, which had an effective duration of 127 hours and a frequency range of 1.2-1.5 GHz, this limit extends to lower neutrino energies than those from previous lunar radio experiments, with a detection threshold below 10^20 eV. The calculation of our limit allows for the possibility of lunar-origin pulses being misidentified as local radio interference, and includes the effect of small-scale lunar surface roughness. The targeting strategy of the observations also allows us to place a directional limit on the neutrino flux from the nearby radio galaxy Centaurus A.

  10. A minimal width of the arrival direction distribution of ultra-high energy cosmic rays detected with the Yakutsk array

    CERN Document Server

    Ivanov, A A

    2015-01-01

    This paper presents the results of searches for anisotropy in arrival directions of ultra-high energy cosmic rays detected with the Yakutsk Array during the 1974--2008 observational period together with available data from other giant extensive air shower arrays working at present. A method of analysis based on a comparison of the minimal width of distributions in equatorial coordinates is applied. As a result, a hypothesis of isotropy in arrival directions is rejected at the $99.5\\%$ significance level. The observed decrease in the minimal width of distribution can be explained by the presence of cosmic ray sources in energy intervals and sky regions according to the recent indications inferred from data of the Yakutsk Array and Telescope Array experiments.

  11. THE MINIMUM WIDTH OF THE ARRIVAL DIRECTION DISTRIBUTION OF ULTRA-HIGH-ENERGY COSMIC RAYS DETECTED WITH THE YAKUTSK ARRAY

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A. A., E-mail: ivanov@ikfia.ysn.ru [Shafer Institute for Cosmophysical Research and Aeronomy, 31 Lenin Avenue, Yakutsk 677980 (Russian Federation)

    2015-05-10

    This paper presents the results of searches for anisotropy in the arrival directions of ultra-high-energy cosmic rays (CRs) detected with the Yakutsk Array during the 1974–2008 observational period as well as searches in available data from other giant extensive air shower arrays working at present. A method of analysis based on a comparison of the minimum width of distributions in equatorial coordinates is used. As a result, a hypothesis of isotropy in arrival directions is rejected at the 99.5% significance level. The observed decrease in the minimum width of the distribution can be explained by the presence of CR sources in energy intervals and sky regions according to recent indications inferred from data of the Yakutsk Array and Telescope Array experiments.

  12. Implications of a Electroweak Triplet Scalar Leptoquark on the Ultra-High Energy Neutrino Events at IceCube

    CERN Document Server

    Mileo, Nicolas; Szynkman, Alejandro

    2016-01-01

    We study the production of scalar leptoquarks at IceCube, in particular, a particle transforming as a triplet under the weak interaction. The existence of electroweak-triplet scalars is highly motivated by models of grand unification and also within radiative seesaw models for neutrino mass generation. In our framework, we extend the Standard Model by a single colored electroweak-triplet scalar leptoquark and analyze its implications on the excess of ultra-high energy neutrino events observed by the IceCube collaboration. We consider only couplings between the leptoquark to first generation leptons and quarks and carry out a statistical analysis to determine the parameters that best describe the IceCube data as well as set $95\\%$ CL upper bounds. We analyze whether this study is still consistent with most up-to-date LHC data and various low energy observables.

  13. Ultra high energy photons as probes of Lorentz symmetry violations in stringy space-time foam models

    Energy Technology Data Exchange (ETDEWEB)

    Maccione, Luca [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Liberati, Stefano [SISSA, Trieste (Italy); INFN, Trieste (Italy); Sigl, Guenter [Hamburg Univ. (Germany). Inst. fuer Theoretische Physik

    2010-03-15

    The time delays between gamma-rays of different energies from extragalactic sources have often been used to probe quantum gravity models in which Lorentz symmetry is violated. It has been claimed that these time delays can be explained by or at least put the strongest available constraints on quantum gravity scenarios that cannot be cast within an effective field theory framework, such as the space-time foam, D-brane model. Here we show that this model would predict too many photons in the ultra-high energy cosmic ray flux to be consistent with observations. The resulting constraints on the space-time foam model are much stronger than limits from time delays and allow for Lorentz violations effects way too small for explaining the observed time delays. (orig.)

  14. Detection of ultra high energy neutrinos with an underwater very large volume array of acoustic sensors: A simulation study

    CERN Document Server

    Karg, T

    2006-01-01

    This thesis investigates the detection of ultra high energy (E > 1 EeV) cosmic neutrinos using acoustic sensors immersed in water. The method is based on the thermoacoustic model describing the production of microsecond bipolar acoustic pulses by neutrino-induced particle cascades. These cascades locally heat the medium which leads to rapid expansion and a short sonic pulse detectable in water with hydrophones over distances of several kilometres. This makes acoustic detection an approach complementary to todays optical Cerenkov and radio Cerenkov detectors, and could help to reduce the respective systematic uncertainties. In this work a complete simulation / reconstruction chain for a submarine acoustic neutrino telescope is developed, and the sensitivity of such a detector to a diffuse flux of ultra highenergy cosmic neutrinos is estimated.

  15. Photodetection Aspects of JEM-EUSO and Studies of the Ultra-High Energy Cosmic Ray Sky

    CERN Document Server

    Blaksley, Carl

    2014-01-01

    In this thesis, an introduction to the Ultra-High Energy Cosmic Ray (UHECR) field is given, including air shower physics, UHECR astrophysics, and experimental techniques. The current questions in UHECR physics are mentioned, along with the experimental challenges encountered in the field. The physics of air fluorescence is also presented, and the JEM-EUSO experiment is introduced in detail. The original contributions in this thesis are divided into experimental work on photodetection aspects of JEM-EUSO and phenomenological studies of UHECR composition and source statistics. A comprehensive introduction to photomultiplier tubes (PMTs) and single photoelectron counting are given, and the measurement of PMT efficiency with an uncertainty of a few percent is discussed in detail. An experimental setup for measuring the air fluorescence yield is also introduced, and tests of the EUSO-Balloon high voltage power supply prototype are presented. A setup for sorting the JEM-EUSO PMTs is developed, including the assembl...

  16. First Constraints on the Ultra-High Energy Neutrino Flux from a Prototype Station of the Askaryan Radio Array

    CERN Document Server

    Allison, P; Beatty, J J; Besson, D Z; Bora, C; Chen, Chih-Ching; Chen, Pisin; Li, Chuan-Jui; Connolly, A; Davies, J P; Duvernois, M; Fox, B; Gorham, P W; Hanson, K; Hill, B; Hoffman, K D; Hong, E; Hu, Li-Ce; Ishihara, A; Karle, A; Kelley, J; Kravchenko, I; Landsman, H; Laundrie, A; Liu, Tsungche; Lu, M -Y; Manau, R; Mase, K; Meures, T; Miki, C; Murchadha, A; Nam, Jiwoo; Nichol, R J; Nir, G; Pfendner, C G; Ratzlaff, K; Richman, M; Rotter, B; Sandstrom, P; Seckel, D; Shultz, A; Stockham, J; Stockham, M; Sullivan, M; Touart, J; Tu, Hsin-Yi; Varner, G S; Yoshida, S; Young, R

    2014-01-01

    The Askaryan Radio Array (ARA) is an ultra-high energy ($>10^{17}$ eV) cosmic neutrino detector in phased construction near the South Pole. ARA searches for radio Cherenkov emission from particle cascades induced by neutrino interactions in the ice using radio frequency antennas ($\\sim150-800$ MHz) deployed at a design depth of 200 m in the Antarctic ice. A prototype ARA Testbed station was deployed at $\\sim30$ m depth in the 2010-2011 season and the first three full ARA stations were deployed in the 2011-2012 and 2012-2013 seasons. We present the first neutrino search with ARA using data taken in 2011 and 2012 with the ARA Testbed and the resulting constraints on the neutrino flux from $10^{17}-10^{21}$ eV.

  17. Constraints from the first LHC data on hadronic event generators for ultra-high energy cosmic-ray physics

    CERN Document Server

    d'Enterria, David; Pierog, Tanguy; Ostapchenko, Sergey; Werner, Klaus

    2011-01-01

    The determination of the primary energy and mass of ultra-high-energy cosmic-rays (UHECR) generating extensive air-showers in the Earth's atmosphere, relies on the detailed modeling of hadronic multiparticle production at center-of-mass (c.m.) collision energies up to two orders of magnitude higher than those studied at particle colliders. The first Large Hadron Collider (LHC) data have extended by more than a factor of three the c.m. energies in which we have direct proton-proton measurements available to compare to hadronic models. In this work we compare LHC results on inclusive particle production at energies sqrt(s) = 0.9, 2.36, and 7 TeV to predictions of various hadronic Monte Carlo (MC) models used commonly in cosmic-ray (CR) physics (QGSJET, EPOS and SIBYLL). As a benchmark with a standard collider physics model we also show PYTHIA (and PHOJET) predictions with various parameter settings. While reasonable overall agreement is found for some of the MC, none of them reproduces consistently the sqrt(s) ...

  18. Measurement of the ultra high energy cosmic ray flux from data of very inclined showers at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Dembinski, Hans Peter

    2009-12-03

    This work describes the derivation of the energy dependent flux of ultra-high energy cosmic rays from data of very inclined air showers observed with the Pierre Auger Observatory. It focuses on the event class of very inclined air showers with zenith angles larger than 60 . The lateral ground profile of these showers is muon dominated and not radially symmetric around the shower axis due to geomagnetic deflections and other effects. The dependency of this profile on the direction, energy and mass of the cosmic ray is discussed with a mixture of detailed Monte-Carlo simulations and a simplified analytical model of the air shower cascade. It is found in agreement with other studies that the normalized shape of the muon density profile is approximately universal over the range of cosmic ray energies and masses measured at the Pierre Auger Observatory, that the amplitude of the profile is almost proportional to the cosmic ray energy, and that its shower-to-shower fluctuations are sensitive to the mass composition of the cosmic rays. (orig.)

  19. The Lateral Trigger Probability function for the ultra-high energy cosmic ray showers detected by the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, P.; /Lisbon, IST /Lisbon, LIFEP; Aglietta, M.; /INFN, Turin /Turin Observ. /Turin U.; Ahn, E.J.; /Fermilab; Albuquerque, I.F.M.; /Sao Paulo U.; Allard, D.; /APC, Paris; Allekotte, I.; /Centro Atomico Bariloche /Balseiro Inst., San Carlos de Bariloche; Allen, J.; /New York U.; Allison, P.; /Ohio State U.; Alvarez Castillo, J.; /Mexico U.; Alvarez-Muniz, J.; /Santiago de Compostela U.; Ambrosio, M.; /INFN, Naples /Naples U. /Nijmegen U., IMAPP

    2011-01-01

    In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10{sup 17} and 10{sup 19} eV and zenith angles up to 65{sup o}. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations.

  20. The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray showers detected by the Pierre Auger Observatory

    Science.gov (United States)

    Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Anzalone, A.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bäcker, T.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; Benzvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Domenico, M.; de Donato, C.; de Jong, S. J.; de La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; de Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; Del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; di Giulio, C.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filipčič, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gonçalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Góra, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Hrabovský, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lautridou, P.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mićanović, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafá, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Nhung, P. T.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parsons, R. D.; Pastor, S.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Phan, N.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Robledo, C.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-D'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schröder, F.; Schulte, S.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Stapleton, J.; Stasielak, J.; Stephan, M.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tamashiro, A.; Tapia, A.; Tartare, M.; Taşcău, O.; Tavera Ruiz, C. G.; Tcaciuc, R.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tiwari, D. K.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Varela, E.; Vargas Cárdenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Winders, L.; Winnick, M. G.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.

    2011-12-01

    In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 1017 and 1019 eV and zenith angles up to 65°. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations.

  1. The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray Showers detected by the Pierre Auger Observatory

    CERN Document Server

    Abreu, P; Ahn, E J; Albuquerque, I F M; Allard, D; Allekotte, I; Allen, J; Allison, P; Castillo, J Alvarez; Alvarez-Muñiz, J; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Antičić, T; Anzalone, A; Aramo, C; Arganda, E; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avenier, M; Avila, G; Bäcker, T; Balzer, M; Barber, K B; Barbosa, A F; Bardenet, R; Barroso, S L C; Baughman, B; Bäuml, J; Beatty, J J; Becker, B R; Becker, K H; Bellétoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blümer, H; Boháčová, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brogueira, P; Brown, W C; Bruijn, R; Buchholz, P; Bueno, A; Burton, R E; Caballero-Mora, K S; Caramete, L; Caruso, R; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Cheng, S H; Chiavassa, A; Chinellato, J A; Chou, A; Chudoba, J; Clay, R W; Coluccia, M R; Conceição, R; Contreras, F; Cook, H; Cooper, M J; Coppens, J; Cordier, A; Coutu, S; Covault, C E; Creusot, A; Criss, A; Cronin, J; Curutiu, A; Dagoret-Campagne, S; Dallier, R; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; De Domenico, M; De Donato, C; de Jong, S J; De La Vega, G; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; de Vries, K D; Decerprit, G; del Peral, L; del Río, M; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Diaz, J C; Castro, M L Díaz; Diep, P N; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dong, P N; Dorofeev, A; Anjos, J C dos; Dova, M T; D'Urso, D; Dutan, I; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Luis, P Facal San; Tapia, I Fajardo; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Ferrero, A; Fick, B; Filevich, A; Filipčič, A; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Fröhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; García, B; Gámez, D García; Garcia-Pinto, D; Gascon, A; Gemmeke, H; Gesterling, K; Ghia, P L; Giaccari, U; Giller, M; Glass, H; Gold, M S; Golup, G; Albarracin, F Gomez; Berisso, M Gómez; Gonçalves, P; Gonzalez, D; Gonzalez, J G; Gookin, B; Góra, D; Gorgi, A; Gouffon, P; Gozzini, S R; Grashorn, E; Grebe, S; Griffith, N; Grigat, M; Grillo, A F; Guardincerri, Y; Guarino, F; Guedes, G P; Guzman, A; Hague, J D; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hojvat, C; Hollon, N; Holmes, V C; Homola, P; Hörandel, J R; Horneffer, A; Hrabovský, M; Huege, T; Insolia, A; Ionita, F; Italiano, A; Jarne, C; Jiraskova, S; Josebachuili, M; Kadija, K; Kampert, K H; Karhan, P; Kasper, P; Kégl, B; Keilhauer, B; Keivani, A; Kelley, J L; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapp, J; Koang, D -H; Kotera, K; Krohm, N; Krömer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; Lautridou, P; Leão, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; López, R; Agüera, A Lopez; Louedec, K; Bahilo, J Lozano; Lu, L; Lucero, A; Ludwig, M; Lyberis, H; Maccarone, M C; Macolino, C; Maldera, S; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, J; Marin, V; Maris, I C; Falcon, H R Marquez; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martínez; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Mertsch, P; Meurer, C; Mićanović, S; Micheletti, M I; Miller, W; Miramonti, L; Molina-Bueno, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Morris, C; Mostafá, M; Moura, C A; Mueller, S; Muller, M A; Müller, G; Münchmeyer, M; Mussa, R; ‡, G Navarra; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nhung, P T; Niemietz, L; Nierstenhoefer, N; Nitz, D; Nosek, D; Nožka, L; Nyklicek, M; Oehlschläger, J; Olinto, A; Oliva, P; Olmos-Gilbaja, V M; Ortiz, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parra, A; Parsons, R D; Pastor, S; Paul, T; Pech, M; Pękala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrinca, P; Petrolini, A; Petrov, Y; Petrovic, J; Pfendner, C; Phan, N; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Ponce, V H; Pontz, M; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Rautenberg, J; Ravel, O; Ravignani, D; Revenu, B; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rivera, H; Rizi, V; Roberts, J; Robledo, C; de Carvalho, W Rodrigues; Rodriguez, G; Martino, J Rodriguez; Rojo, J Rodriguez; Rodriguez-Cabo, I; Rodríguez-Frías, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Rühle, C; Salamida, F; Salazar, H; Salina, G; Sánchez, F; Santo, C E; Santos, E; Santos, E M; Sarazin, F; Sarkar, B; Sarkar, S; Sato, R; Scharf, N; Scherini, V; Schieler, H; Schiffer, P; Schmidt, A; Schmidt, F; Scholten, O; Schoorlemmer, H; Schovancova, J; Schovánek, P; Schröder, F; Schulte, S; Schuster, D; Sciutto, S J; Scuderi, M; Segreto, A; Settimo, M; Shadkam, A; Shellard, R C; Sidelnik, I; Sigl, G; Lopez, H H Silva; Śmiałkowski, A; Šmída, R; Snow, G R; Sommers, P; Sorokin, J; Spinka, H; Squartini, R; Stanic, S; Stapleton, J; Stasielak, J; Stephan, M; Strazzeri, E; Stutz, A; Suarez, F; Suomijärvi, T; Supanitsky, A D; Šuša, T; Sutherland, M S; Swain, J; Szadkowski, Z; Szuba, M; Tamashiro, A; Tapia, A; Tartare, M; Taşcău, O; Ruiz, C G Tavera; Tcaciuc, R; Tegolo, D; Thao, N T; Thomas, D; Tiffenberg, J; Timmermans, C; Tiwari, D K; Tkaczyk, W; Peixoto, C J Todero; Tomé, B; Tonachini, A; Travnicek, P; Tridapalli, D B; Tristram, G; Trovato, E; Tueros, M; Ulrich, R; Unger, M; Urban, M; Galicia, J F Valdés; Valiño, I; Valore, L; Berg, A M van den; Varela, E; Cárdenas, B Vargas; Vázquez, J R; Vázquez, R A; Veberič, D; Verzi, V; Vicha, J; Videla, M; Villaseñor, L; Wahlberg, H; Wahrlich, P; Wainberg, O; Warner, D; Watson, A A; Weber, M; Weidenhaupt, K; Weindl, A; Westerhoff, S; Whelan, B J; Wieczorek, G; Wiencke, L; Wilczyńska, B; Wilczyński, H; Will, M; Williams, C; Winchen, T; Winnick, M G; Wommer, M; Wundheiler, B; Yamamoto, T; Yapici, T; Younk, P; Yuan, G; Yushkov, A; Zamorano, B; Zas, E; Zavrtanik, D; Zavrtanik, M; Zaw, I; Zepeda, A; Silva, M Zimbres; Ziolkowski, M

    2011-01-01

    In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an extensive air shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10^{17} and 10^{19} eV and zenith angles up to 65 degs. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte-Carlo results sho...

  2. Search for ultra high energy primary photons at the Pierre Auger Observatory

    Science.gov (United States)

    Colalillo, Roberta

    2016-07-01

    The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture in the search for primary photons with energy above 1017 eV over a large portion of the southern sky. Such photons can be detected in principle via the air showers they initiate at such energies, using the complement of Auger Observatory detectors. We discuss the results obtained in diffuse and directional searches for primary photons in the EeV energy range.

  3. Search for ultra high energy primary photons at the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Colalillo Roberta

    2016-01-01

    Full Text Available The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture in the search for primary photons with energy above 1017 eV over a large portion of the southern sky. Such photons can be detected in principle via the air showers they initiate at such energies, using the complement of Auger Observatory detectors. We discuss the results obtained in diffuse and directional searches for primary photons in the EeV energy range.

  4. Acceleration and radiation of ultra-high energy protons in galaxy clusters

    CERN Document Server

    Vannoni, G; Gabici, S; Kelner, S R; Prosekin, A

    2009-01-01

    Clusters of galaxies are believed to be capable to accelerate protons at accretion shocks to energies exceeding 10^18 eV. At these energies, the losses caused by interactions of cosmic rays with photons of the Cosmic Microwave Background Radiation (CMBR) become effective and determine the maximum energy of protons and the shape of the energy spectrum in the cutoff region. The aim of this work is the study of the formation of the energy spectrum of accelerated protons at accretion shocks of galaxy clusters and of the characteristics of their broad band emission. The proton energy distribution is calculated self-consistently via a time-dependent numerical treatment of the shock acceleration process which takes into account the proton energy losses due to interactions with the CMBR. We calculate the energy distribution of accelerated protons, as well as the flux of broad-band emission produced by secondary electrons and positrons via synchrotron and inverse Compton scattering processes. We find that the downstre...

  5. Ultra-High-Energy Cosmic Rays from a Magnetized Strange Star Central Engine for Gamma-Ray Bursts

    CERN Document Server

    Esquivel, O

    2008-01-01

    Ultra-high-energy cosmic rays (UHECRs) have been tried to be related to the most varied and powerful sources known in the universe. Gamma-ray bursts (GRBs) are natural candidates. Here, we argue that cosmic rays can be accelerated by large amplitude electromagnetic waves (LAEMWs) when the MHD approximation of the field in the wind generated by the GRB's magnetized central engine breaks down. The central engine considered here is a strange star born with differential rotation from the accretion induced conversion of a neutron star into a strange star in a low-mass X-ray binary system. The LAEMWs generated this way accelerate light ions to the highest energies $E = q\\eta\\Delta\\Phi_{max}$ with an efficiency $\\eta \\sim 10^{-1}$ that accounts for all plausible energy losses. Alternatively, we also consider the possibility that, once formed, the LAEMWs are unstable to creation of a relativistically strong electromagnetic turbulence due to an overturn instability. Under this assumption, a lower limit to the efficien...

  6. EleCa: a Monte Carlo code for the propagation of extragalactic photons at ultra-high energy

    CERN Document Server

    Settimo, Mariangela

    2013-01-01

    Ultra high energy photons play an important role as an independent probe of the photo-pion production mechanism by UHE cosmic rays. Their observation, or non-observation, may constrain astrophysical scenarios for the origin of UHECRs and help to understand the nature of the flux suppression observed by several experiments at energies above 10$^{19.5}$ eV. Whereas the interaction length of UHE photons above 10$^{17}$ eV is only of a few hundred kpc up to tenths of Mpc, photons can interact with the extragalactic background radiation leading to the development of electromagnetic cascades which affect the fluxes of photons observed at Earth. The interpretation of the current experimental results rely on the simulations of the UHE photon propagation. In this contribution, we present the novel Monte Carlo code "EleCa" to simulate the \\emph{Ele}ctromagnetic \\emph{Ca}scading initiated by high-energy photons and electrons. The distance within which we expect to observe UHE photons is discussed and the flux of GZK pho...

  7. Hard X-ray and Gamma-ray Emission Induced by Ultra-High Energy Protons in Cluster Accretion Shocks

    CERN Document Server

    Inoue, S; Sugiyama, N; Inoue, Susumu; Aharonian, Felix A.; Sugiyama, Naoshi

    2005-01-01

    All sufficiently massive clusters of galaxies are expected to be surrounded by strong accretion shocks, where protons can be accelerated to $\\sim 10^{18}$-$10^{19}$ eV under plausible conditions. Such protons interact with the cosmic microwave background and efficiently produce very high energy electron-positron pairs, which then radiate synchrotron and inverse Compton emission, peaking respectively at hard X-ray and TeV gamma-ray energies. Characterized by hard spectra (photon indices $\\sim 1.5$) and spatial distribution tracing the accretion shock, these can dominate over other nonthermal components depending on the shock magnetic field. HESS and other Cerenkov telescopes may detect the TeV emission from nearby clusters, notwithstanding its extended nature. The hard X-rays may be observable by future imaging facilities such as NeXT, and possibly also by ASTRO-E2/HXD. Such detections will not only provide a clear signature of ultra-high energy proton acceleration, but also an important probe of the accretion...

  8. Ultra High Energy Solid-State Batteries for Next Generation Space Power Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The use of lithium (Li) metal as an anode material has emerged as one highly attractive option for achieving high specific energy due to lithium having the highest...

  9. Increasing durability and lowering the overall cost of wave energy converters using Ultra High Performance Concrete

    DEFF Research Database (Denmark)

    Jepsen, Michael S.; Damkilde, Lars; Hansen, Niels A.

    2013-01-01

    Lowering the overall cost of wave energy converters is a necessity for creating a feasible solution to renewable energy. The design of wave energy converters is in general based on traditional steel design methods. In the design of steel structures subjected to significant dynamical loading...... and a harsh environment issues such fatigue resistance and durability are of major concern. The welded joints in steel structures significantly reduce the fatigue resistance and give a low utilization ratio of the steel material. Furthermore is coating of all exposed steel surfaces a necessity to secure...... as primary material in the design of wave energy converters is a feasible and promising solution, which reduce the overall cost of the structure significantly. This will be illustrated by means of a feasibility study carried out on the Wavestar project, where special attention is pointed at the arm and float...

  10. Advanced Nanostructured Cathode for Ultra High Specific Energy Lithium Ion Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Integrate advanced nanotechnology with energy storage technology to develop advanced cathode materials for use in Li-ion batteries while maintaining a high level of...

  11. Bubbler: A Novel Ultra-High Power Density Energy Harvesting Method Based on Reverse Electrowetting

    OpenAIRE

    Tsung-Hsing Hsu; Supone Manakasettharn; J. Ashley Taylor; Tom Krupenkin

    2015-01-01

    We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse. Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alon...

  12. Bubbler: A Novel Ultra-High Power Density Energy Harvesting Method Based on Reverse Electrowetting.

    Science.gov (United States)

    Hsu, Tsung-Hsing; Manakasettharn, Supone; Taylor, J Ashley; Krupenkin, Tom

    2015-11-16

    We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse. Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alone. This energy conversion approach is particularly well suited for energy harvesting applications and can enable effective coupling to a broad array of mechanical systems including such ubiquitous but difficult to utilize low-frequency energy sources as human and machine motion. The method can be scaled from a single micro cell with 10(-6) W output to power cell arrays with a total power output in excess of 10 W. This makes the fabrication of small light-weight energy harvesting devices capable of producing a wide range of power outputs feasible.

  13. Bubbler---A Novel Ultra High Power Density Energy Harvesting Method Based on Reverse Electrowetting

    Science.gov (United States)

    Hsu, Tsung-Hsing

    A novel approach to direct conversion of mechanical energy into electrical energy has been proposed and experimentally and theoretically investigated. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse inside a conductive liquid placed in contact with a dielectric-covered electrode. Fast bubble dynamics, used in conjunction with REWOD, can enable extremely high power densities, in excess of 10 kW/m2. The method can be scaled in power from microwatts to tens of watts, and can enable direct coupling to a wide range of mechanical energy sources, which make it particularly attractive for energy harvesting applications. We believe that this approach can enable extraction of useful energy from various non-traditional sources including thermal expansion of buildings, human motion, and vehicle and machinery movement. Also, this makes the fabrication of small light-weight energy harvesting devices capable of producing a wide range of power outputs feasible.

  14. Sensitivity of the IceCube detector for ultra-high energy electron neutrino events

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, Bernhard

    2008-07-16

    IceCube is a neutrino telescope currently under construction in the glacial ice at South Pole. At the moment half of the detector is installed, when completed it will instrument 1 km{sup 3} of ice providing a unique experimental setup to detect high energy neutrinos from astrophysical sources. In this work the sensitivity of the complete IceCube detector for a diffuse electron-neutrino flux is analyzed, with a focus on energies above 1 PeV. Emphasis is put on the correct simulation of the energy deposit of electromagnetic cascades from charged-current electron-neutrino interactions. Since existing parameterizations lack the description of suppression effects at high energies, a simulation of the energy deposit of electromagnetic cascades with energies above 1 PeV is developed, including cross sections which account for the LPM suppression of bremsstrahlung and pair creation. An attempt is made to reconstruct the direction of these elongated showers. The analysis presented here makes use of the full charge waveform recorded with the data acquisition system of the IceCube detector. It introduces new methods to discriminate efficiently between the background of atmospheric muons, including muon bundles, and cascade signal events from electron-neutrino interactions. Within one year of operation of the complete detector a sensitivity of 1.5.10{sup -8}E{sup -2} GeVs{sup -1}sr{sup -1}cm{sup -2} is reached, which is valid for a diffuse electron neutrino flux proportional to E{sup -2} in the energy range from 16 TeV to 13 PeV. Sensitivity is defined as the upper limit that could be set in absence of a signal at 90% confidence level. Including all neutrino flavors in this analysis, an improvement of at least one order of magnitude is expected, reaching the anticipated performance of a diffuse muon analysis. (orig.)

  15. Ultra-high energy cosmic rays: from GeV to ZeV

    CERN Document Server

    Medina-Tanco, G A

    2006-01-01

    Cosmic ray (CR) particles arrive at the top of the Earth's atmosphere at a rate of around 1000 per square meter per second. They are mostly ionized nuclei - about 90% protons, 9% alpha particles traces of heavier nuclei and approximately 1% electrons. CRs are characterized by their high energies: most cosmic rays are relativistic, having kinetic energies comparable to or somewhat greater than their rest masses. A very few of them have ultra-relativistic energies extending beyond 100 EeV (tens of joules). In this series of lectures, delivered at the 2005 Mexican School of Astrophysics, an overview of the main experimental characteristics of the CR flux and their astrophysical significance is given. Particular emphasis is given to the upper end of the CR energy spectrum. Unfortunately, due to space limitations, only a fraction of the original content of the lectures is included in the present manuscript. In particular, the production mechanisms are not included and the fundamental topic of anisotropies is only ...

  16. Macroscopic modelling of radio emission from ultra-high-energy-cosmic-ray-induced air showers

    NARCIS (Netherlands)

    de Vries, Krijn Dominique

    2012-01-01

    De aarde wordt dagelijks vanuit de ruimte gebombardeerd door kosmische deeltjes met extreem hoge energieën. Tijdens botsingen in onze atmosfeer ontstaat een lawine van secundaire deeltjes, typisch een miljoen tot een miljard in aantal, welke met de snelheid van het licht richting aarde beweegt. Een

  17. The sensitivity of past and near-future lunar radio experiments to ultra-high-energy cosmic rays and neutrinos

    Science.gov (United States)

    Bray, J. D.

    2016-04-01

    Various experiments have been conducted to search for the radio emission from ultra-high-energy (UHE) particles interacting in the lunar regolith. Although they have not yielded any detections, they have been successful in establishing upper limits on the flux of these particles. I present a review of these experiments in which I re-evaluate their sensitivity to radio pulses, accounting for effects which were neglected in the original reports, and compare them with prospective near-future experiments. In several cases, I find that past experiments were substantially less sensitive than previously believed. I apply existing analytic models to determine the resulting limits on the fluxes of UHE neutrinos and cosmic rays (CRs). In the latter case, I amend the model to accurately reflect the fraction of the primary particle energy which manifests in the resulting particle cascade, resulting in a substantial improvement in the estimated sensitivity to CRs. Although these models are in need of further refinement, in particular to incorporate the effects of small-scale lunar surface roughness, their application here indicates that a proposed experiment with the LOFAR telescope would test predictions of the neutrino flux from exotic-physics models, and an experiment with a phased-array feed on a large single-dish telescope such as the Parkes radio telescope would allow the first detection of CRs with this technique, with an expected rate of one detection per 140 h.

  18. Limits on the Transient Ultra-High Energy Neutrino Flux from Gamma-Ray Bursts (GRB) Derived from RICE Data

    CERN Document Server

    Hussain, S; al, et

    2006-01-01

    We present limits on ultra-high energy (UHE; E(nu)>1 PeV) neutrino fluxes from gamma-ray bursts (GRB), based on recently presented data, limits, and simulations from the RICE experiment. We use data from five recorded transients with sufficient photon spectral shape and redshift information to derive an expected neutrino flux, assuming that the observed photons are linked to neutrino production through pion decay via the well-known 'Waxman-Bahcall' prescription. Knowing the declination of the observed burst, as well as the RICE sensitivity as a function of polar angle and the previously published non-observation of any neutrino events allows an estimate of the sensitivity to a given neutrino flux. Although several orders of magnitude weaker than the expected fluxes, our GRB neutrino flux limits are nevertheless the first in the PeV--EeV energy regime. For completeness, we also provide a listing of other bursts, recorded at times when the RICE experiment was active, but requiring some assumptions regarding lum...

  19. Model-dependent estimate on the connection between fast radio bursts and ultra high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang; Zhou, Bei; He, Hao-Ning; Fan, Yi-Zhong; Wei, Da-Ming, E-mail: yzfan@pmo.ac.cn [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Science, Nanjing 210008 (China)

    2014-12-10

    The existence of fast radio bursts (FRBs), a new type of extragalatic transient, has recently been established, and quite a few models have been proposed. In this work, we discuss the possible connection between the FRB sources and ultra high energy (>10{sup 18} eV) cosmic rays. We show that in the blitzar model and the model of merging binary neutron stars, which includes the huge energy release of each FRB central engine together with the rather high rate of FRBs, the accelerated EeV cosmic rays may contribute significantly to the observed ones. In other FRB models, including, for example, the merger of double white dwarfs and the energetic magnetar radio flares, no significant EeV cosmic ray is expected. We also suggest that the mergers of double neutron stars, even if they are irrelevant to FRBs, may play a nonignorable role in producing EeV cosmic ray protons if supramassive neutron stars are formed in a sufficient fraction of mergers and the merger rate is ≳ 10{sup 3} yr{sup –1} Gpc{sup –3}. Such a possibility will be unambiguously tested in the era of gravitational wave astronomy.

  20. A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, P.; Andringa, S. [LIP and Instituto Superior Técnico, Technical University of Lisbon (Portugal); Aglietta, M. [Istituto di Fisica dello Spazio Interplanetario (INAF), Università di Torino and Sezione INFN, Torino (Italy); Ahlers, M. [University of Wisconsin, Madison, WI (United States); Ahn, E.J. [Fermilab, Batavia, IL (United States); Albuquerque, I.F.M. [Universidade de São Paulo, Instituto de Física, São Paulo, SP (Brazil); Allard, D. [Laboratoire AstroParticule et Cosmologie (APC), Université Paris 7, CNRS-IN2P3, Paris (France); Allekotte, I. [Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina); Allen, J. [New York University, New York, NY (United States); Allison, P. [Ohio State University, Columbus, OH (United States); Almela, A. [Universidad Tecnológica Nacional - Facultad Regional Buenos Aires, Buenos Aires (Argentina); Castillo, J. Alvarez [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Alvarez-Muñiz, J. [Universidad de Santiago de Compostela (Spain); Ambrosio, M.; Aramo, C. [Università di Napoli ' Federico II' and Sezione INFN, Napoli (Italy); Aminaei, A. [IMAPP, Radboud University Nijmegen (Netherlands); Anchordoqui, L. [University of Wisconsin, Milwaukee, WI (United States); Antici' c, T. [Rudjer Boškovi' c Institute, 10000 Zagreb (Croatia); Arganda, E. [IFLP, Universidad Nacional de La Plata and CONICET, La Plata (Argentina); Arqueros, F., E-mail: auger_spokesperson@fnal.gov [Universidad Complutense de Madrid, Madrid (Spain); Collaboration: Pierre Auger Collaboration; and others

    2012-04-01

    Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Véron-Cetty Véron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt–L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three methods can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. Using data taken from January 1, 2004 to July 31, 2010 we examined the 20,30,...,110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.

  1. A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory

    Science.gov (United States)

    Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antici'c, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bäcker, T.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Bohácová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; del Río, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Filevich, A.; Filipcic, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Horvath, P.; Hrabovský, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mi'canovi'c, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Porcelli, A.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schröder, F.; Schulte, S.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Sima, O.; 'Smiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Taşcău, O.; Tavera Ruiz, C. G.; Tcaciuc, R.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Varela, E.; Vargas Cárdenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.

    2012-04-01

    Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Véron-Cetty Véron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three methods can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. Using data taken from January 1, 2004 to July 31, 2010 we examined the 20,30,...,110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.

  2. A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, P.

    2012-01-01

    Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three methods can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. Using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ..., 110 highest energy events with a corresponding minimum energy threshold of about 51 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.

  3. New detection technologies for ultra-high energy cosmic rays and neutrinos

    Directory of Open Access Journals (Sweden)

    Böser Sebastian

    2013-06-01

    Full Text Available Even with an accumulated data set from an integrated six years of lifetime from the Auger experiment, no point sources of charged cosmic rays have be identified at the highest energies. Significantly increased apertures such as promised by the JEMEUSO mission will be required to identify these sources from the cosmic ray signatures themselves. However, in employing water-cherenkov surface detectors as well as fluorescence telescopes, Auger has demonstrated the power provided by the hybrid technology approach. New detection technologies thus provide a valuable tool, in particular for the study of systematic effects. Over the past decade, in particular radio detection of cosmic ray air-showers has become a viable future detection technology to enhance and complement existing air-shower experiments. Following the proof-of-principle provided by the Lopes experiment, this technology is now being pursued in all major air-shower detectors. In the MHz regime, the radio signal is dominated by geomagnetic emission from the electrons deflected in the earth magnetic field, with secondary contributions from a global charge excess. As the majority of the energy in the shower is carried by these electron and the radio signal traverses the atmosphere basically unattenuated, this approach not only promises superior energy resolution but may also provide an independent handle on the longitudinal shower development and hence the primary composition. Theoretical signal predictions provided by detailed Monte-Carlo simulations as well as analytic shower parametrizations are in good agreement with measurements provided by the AERA and Codalema experiments. Recent efforts also include studies of the radio emission in the GHz regime, where the ambient noise is significantly reduced, yet the emission mechanism in this regime has not been firmly established yet. As neutrinos are not deflected in the intergalactic magnetic fields, the detection of neutrino-induced cascades

  4. Magnetowave Induced Plasma Wakefield Acceleration for Ultra High Energy Cosmic Rays

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Feng-Yin; /Taiwan, Natl. Chiao Tung U. /Taiwan, Natl. Taiwan U.; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC; Lin, Guey-Lin; /Taiwan, Natl. Chiao Tung U. /Taiwan, Natl. Taiwan U.; Noble, Robert; /SLAC; Sydora, Richard; /Alberta U.

    2009-10-17

    Magnetowave induced plasma wakefield acceleration (MPWA) in a relativistic astrophysical outflow has been proposed as a viable mechanism for the acceleration of cosmic particles to ultrahigh energies. Here we present simulation results that clearly demonstrate the viability of this mechanism for the first time. We invoke the high frequency and high speed whistler mode for the driving pulse. The plasma wakefield obtained in the simulations compares favorably with our newly developed relativistic theory of the MPWA. We show that, under appropriate conditions, the plasma wakefield maintains very high coherence and can sustain high-gradient acceleration over hundreds of plasma skin depths. Invoking active galactic nuclei as the site, we show that MPWA production of ultrahigh energy cosmic rays beyond ZeV (10{sup 21} eV) is possible.

  5. New Limits on the Ultra-High Energy Cosmic Neutrino Flux from the ANITA Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gorham, P.W.; Allison, P.; /Hawaii U.; Barwick, S.W.; /UC, Irvine; Beatty, J.J.; /Ohio State U.; Besson, D.Z.; /Kansas U.; Binns, W.R.; /Washington U., St. Louis; Chen, C.; /Taiwan, Natl. Taiwan U.; Chen, P.; /SLAC; Clem, J.M.; /Delaware U.; Connolly, A.; /University Coll. London; Dowkontt, P.F.; /Washington U., St. Louis; DuVernois, M.A.; /Minnesota U.; Field, R.C.; /SLAC; Goldstein, D.; /UC, Irvine; Goodhue, A.; /UCLA; Hast, C.; /SLAC; Hebert, C.L.; /Hawaii U.; Hoover, S.; /UCLA; Israel, M.H.; /Washington U., St. Louis; Kowalski, J.; Learned, J.G.; /Hawaii U. /Caltech, JPL /Hawaii U. /Minnesota U. /Hawaii U. /Ohio State U. /Hawaii U. /UC, Irvine /Taiwan, Natl. Taiwan U. /Caltech, JPL /SLAC /University Coll. London /Ohio State U. /SLAC /Hawaii U. /UCLA /Delaware U. /Hawaii U. /SLAC /Taiwan, Natl. Taiwan U.

    2011-12-01

    We report initial results of the first flight of the Antarctic Impulsive Transient Antenna (ANITA-1) 2006-2007 Long Duration Balloon flight, which searched for evidence of a diffuse flux of cosmic neutrinos above energies of E{sub v} = 3 x 10{sup 18} eV. ANITA-1 flew for 35 days looking for radio impulses due to the Askaryan effect in neutrino-induced electromagnetic showers within the Antarctic ice sheets. We report here on our initial analysis, which was performed as a blind search of the data. No neutrino candidates are seen, with no detected physics background. We set model-independent limits based on this result. Upper limits derived from our analysis rule out the highest cosmogenic neutrino models. In a background horizontal-polarization channel, we also detect six events consistent with radio impulses from ultrahigh energy extensive air showers.

  6. A Model for Pseudo-Dirac Neutrinos: Leptogenesis and Ultra-High Energy Neutrinos

    CERN Document Server

    Ahn, Y H; Kim, C S

    2016-01-01

    We propose a model where sterile neutrinos are introduced to make light neutrinos to be pseudo-Dirac particles. It is shown how tiny mass splitting necessary for realizing pseudo-Dirac neutrinos can be achieved. Within the model, we show how leptogenesis can be successfully generated. Motivated by the recent observation of very high energy neutrino events at IceCube, we study a possibility to observe the effects of the pseudo-Dirac property of neutrinos by performing astronomical-scale baseline experiments to uncover the oscillation effects of very tiny mass splitting. Using the result of global fit to neutrino data for the input of neutrino mixing angles and CP phase at $1\\sigma$ C.L. and fixing neutrino energy and mass splittings, we study how the oscillation effects induced by pseudo-Dirac neutrinos may affect the track-to-shower ratio obtained from IceCube data. We also discuss future prospect to observe the effects of the pseudo-Dirac property of neutrinos at high energy neutrino experiments.

  7. Overview of lunar detection of ultra-high energy particles and new plans for the SKA

    Directory of Open Access Journals (Sweden)

    James Clancy W.

    2017-01-01

    In this contribution, the status of lunar particle detection is reviewed, with particular attention paid to outstanding theoretical questions, and the technical challenges of using a giant radio array to search for nanosecond pulses. The activities of SKA’s High Energy Cosmic Particles Focus Group are described, as is a roadmap by which this group plans to incorporate this detection mode into SKA-low observations. Estimates for the sensitivity of SKA-low phases 1 and 2 to UHE particles are given, along with the achievable science goals with each stage. Prospects for near-future observations with other instruments are also described.

  8. Sterile neutrinos, dark matter, and resonant effects in ultra high energy regimes

    Directory of Open Access Journals (Sweden)

    O.G. Miranda

    2015-05-01

    Full Text Available Interest in light dark matter candidates has recently increased in the literature; some of these works consider the role of additional neutrinos, either active or sterile. Furthermore, extragalactic neutrinos have been detected with energies higher than have ever been reported before. This opens a new window of opportunities to the study of neutrino properties that were unreachable up to now. We investigate how an interaction potential between neutrinos and dark matter might induce a resonant enhancement in the oscillation probability, an effect that may be tested with future neutrino data.

  9. Plasma effects on extragalactic ultra-high-energy cosmic ray hadron beams in cosmic voids

    Energy Technology Data Exchange (ETDEWEB)

    Krakau, Steffen; Schlickeiser, Reinhard [Institut fur Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitaet Bochum (Germany)

    2015-05-01

    The linear instability of an ultrarelativistic hadron beam (Γ{sub b} ∼ 10{sup 6}) in the unmagnetized intergalactic medium is investigated with respect to the excitation of collective electrostatic and aperiodic electromagnetic fluctuations. This analysis is important for the propagation of extragalactic ultrarelativistic cosmic rays (E > 10{sup 15} eV) from their distant sources to Earth. We calculate minimum instability growth times which are orders of magnitude shorter than the cosmic ray propagation time in the IGM. Due to nonlinear effects, especially the modulation instability, the cosmic ray beam stabilize and can propagate with nearly no energy loss through the intergalactic medium.

  10. Sterile neutrinos, dark matter, and resonant effects in ultra high energy regimes

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, O.G., E-mail: omr@fis.cinvestav.mx [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740 07000 México, D.F. (Mexico); Moura, C.A., E-mail: celio.moura@ufabc.edu.br [Universidade Federal do ABC (UFABC), Centro de Ciências Naturais e Humanas, Rua Santa Adélia, 166, 09210-170 Santo André, SP (Brazil); Parada, A., E-mail: alexander.parada00@usc.edu.co [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740 07000 México, D.F. (Mexico)

    2015-05-11

    Interest in light dark matter candidates has recently increased in the literature; some of these works consider the role of additional neutrinos, either active or sterile. Furthermore, extragalactic neutrinos have been detected with energies higher than have ever been reported before. This opens a new window of opportunities to the study of neutrino properties that were unreachable up to now. We investigate how an interaction potential between neutrinos and dark matter might induce a resonant enhancement in the oscillation probability, an effect that may be tested with future neutrino data.

  11. Experiment to search for ultra high energy. gamma. -ray sources from the South Pole

    Energy Technology Data Exchange (ETDEWEB)

    Smith, N.J.T.; Perrett, J.C.; Pomerantz, M.A.; Hillas, A.M.; Ogden, P.A.; Patel, M.; Reid, R.J.O.; Watson, A.A.

    1989-04-01

    We describe the construction and performance characteristics of an extensive air shower array which has been established at the geographic South Pole. The experiment has been designed to search for sources for cosmic rays with primary energies above 50 TeV with an angular resolution of about 1/sup 0/. The array has an enclosed area of 6235 m/sup 2/ and is at an altitude of 2835 m (695 g cm/sup -2/). The unique advantage of the site is the circumpolar nature of all candidate sources, including SN1987A, which lie at a constant zenith angle.

  12. Extensive Air Showers and Ultra High-Energy Cosmic Rays: A Historical Review

    CERN Document Server

    Kampert, Karl-Heinz

    2012-01-01

    The discovery of extensive air showers by Rossi, Schmeiser, Bothe, Kolh\\"orster and Auger at the end of the 1930s, facilitated by the coincidence technique of Bothe and Rossi, led to fundamental contributions in the field of cosmic ray physics and laid the foundation for high-energy particle physics. Soon after World War II a cosmic ray group at MIT in the USA pioneered detailed investigations of air shower phenomena and their experimental skill laid the foundation for many of the methods and much of the instrumentation used today. Soon interests focussed on the highest energies requiring much larger detectors to be operated. The first detection of air fluorescence light by Japanese and US groups in the early 1970s marked an important experimental breakthrough towards this end as it allowed huge volumes of atmosphere to be monitored by optical telescopes. Radio observations of air showers, pioneered in the 1960s, are presently experiencing a renaissance and may revolutionise the field again. In the last 7 dec...

  13. Permafrost - An Alternative Target Material for Ultra High Energy Neutrino Detection?

    CERN Document Server

    Nahnhauer, R; Tosi, D

    2007-01-01

    The detection of cosmic neutrinos with energies above 1017 eV got growing interest during recent years. Possible target materials for in-matter arrays of ~100 km3 size under discussion are water, ice and rock salt. Here we propose to investigate permafrost as an additional alternative, covering ~20% of Earth land surface and reaching down to more than 1000 m depth at certain locations. If sufficiently large attenuation lengths for radio and acoustic signals can be demonstrated by in-situ measurements, the construction of a large hybrid array within this material may be possible in the Northern hemisphere. Properties and problems of a possible location in Siberia are discussed below. Some acoustic data are compared to laboratory measurements using "artificial" permafrost.

  14. Neutrinos from active black holes, sources of ultra high energy cosmic rays

    CERN Document Server

    Becker, Julia K

    2008-01-01

    A correlation between the highest energy Cosmic Rays (above ~60 EeV) and the distribution of Active Galactic Nuclei (AGN) gives rise to a prediction of neutrino production in the same sources. In this paper, we present a detailed AGN model, predicting neutrino production near the foot of the jet, where the photon field from the disk creates a high optical depth for proton-photon interactions. The protons escape from later shocks where the emission region is optically thin for proton-photon interactions. Consequently, Cosmic Rays are predicted to come from FR-I galaxies, independent of the orientation of the source. Neutrinos, on the other hand, are only observable from sources directing their jet towards Earth, i.e. flat spectrum radio quasars, due to the strongly beamed neutrino emission.

  15. Search for Ultra-High Energy Photons with the Pierre Auger Observatory

    CERN Document Server

    Kuempel, Daniel

    2016-01-01

    The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture for the search of photons with energy above 100 PeV. In this contribution recent results are presented including the diffuse search for photons and the directional search for photon point sources. The derived limits are of considerable astrophysical interest: Diffuse limits place severe constraints on top-down models and start to touch the predicted GZK photon flux range while directional limits can exclude the continuation of the electromagnetic flux from measured TeV sources with a significance of more than 5$\\sigma$. Finally, prospects of neutral particle searches for the upcoming detector upgrade AugerPrime are highlighted.

  16. Layered water Cherenkov detector for the study of ultra high energy cosmic rays

    CERN Document Server

    Letessier-Selvon, Antoine; Blanco, Miguel; Maris, Ioana C; Settimo, Mariangela

    2014-01-01

    We present a new design for the water Cherenkov detectors that are in use in various cosmic ray observatories. This novel design can provide a significant improvement in the independent measurement of the muonic and electromagnetic component of extensive air showers. From such multi-component data an event by event classification of the primary cosmic ray mass becomes possible. According to popular hadronic interaction models, such as EPOS-LHC or QGSJetII-04, the discriminating power between iron and hydrogen primaries reaches Fisher values of $\\sim$ 2 or above for energies in excess of $10^{19}$ eV with a detector array layout similar to that of the Pierre Auger Observatory.

  17. Tidal disruption flares as the source of ultra-high energy cosmic rays

    Directory of Open Access Journals (Sweden)

    Farrar G.R.

    2012-12-01

    Full Text Available The optical spectral energy distributions of two tidal disruption flares identified by van Velzen et al. (2011 in archival SDSS data, are found to be well-fit by a thin-accretion-disk model. Furthermore, the inferred Supermassive Black Hole mass values agree well with the SMBH masses estimated from the host galaxy properties. Integrating the model SEDs to include shorter wavelength contributions provides an estimate of the bolometric luminosities of the accretion disks. The resultant bolometric luminosities are well in excess of the minimum required for accelerating UHECR protons. In combination with the recent observational estimate of the TDF rate (van Velzen and Farrar, these Proceedings, the results presented here strengthen the case that transient jets formed in tidal disruption events may be responsible for accelerating all or most UHECRs.

  18. The importance of muon information on primary mass discrimination of ultra-high energy cosmic rays

    CERN Document Server

    Supanitsky, D; Medina-Tanco, G; Etchegoyen, A; Allekotte, I; Berisso, M G; De Souza, V; Medina, C; Ortiz, J A; Shellard, R

    2005-01-01

    Several methods can be used to perform statistical inference of primary composition of cosmic rays measured with water Cerenkov detectors as those in use at the Pierre Auger Southern Observatory. In the present work we assess the impact of additional information about the number of muons in the air shower, on the problem of statistical primary mass discrimination. Several tools are studied, including neural networks, principal component analysis and traditional methods in current use in the field. For our case study we use hypothetical plastic scintillators as muon counters, buried at the side and outside the shade of the water Cerenkov tanks. The study is extended to protons and Fe nuclei impinging on an array with two different spacings, 750 and 1500 m and, therefore, suitable to the 1-10 EeV energy range. A prototype of such a detector is under construction.

  19. Innermost stable circular orbit near dirty black holes in magnetic field and ultra-high energy particle collisions

    CERN Document Server

    Zaslavskii, O B

    2014-01-01

    We consider the behavior of the innermost stable circular orbit (ISCO) in the magnetic field $B$ near "dirty" (surrounded by matter) axially-symmetric black holes. The cases of near-extremal, extremal and nonextremal black holes is analyzed. For nonrotating extremal or nonextremal black holes, in the strong magnetic field ISCO approaches the horizon. Rotation destroys this phenomenon. For near-extremal dirty black holes, the ISCO radius depends on $B$ in the main approximation in contrast to the Kerr case where such dependence appears in the next correction with respect to the small surface gravity. In terms of the dimensionless variables, the angular momentum and radius of ISCO look model-independent in the main approximation in $B^{-1}$. We also study the collisions between two particles which result in the ultra-high energy $E_{c.m.}$ in the centre of mass frame. Two scenarios are considered - when one particle moves on the near-horizon ISCO or when collision occurs on the horizon, one particle having the ...

  20. Pilot study of ultra-high energy Cosmic rays through their Space – Atmospheric interactions – COSAT

    Directory of Open Access Journals (Sweden)

    Isar Paula Gina

    2015-01-01

    Full Text Available One hundred years after the discovery of cosmic rays, the study of charged ultra-high energy cosmic rays remains a vital activity in fundamental physics. While primary cosmic rays could not be measured directly until it was possible to get the detectors high in the atmosphere using balloons or spacecraft, nowadays very energetic cosmic rays are detected indirectly by ground-based experiments measuring their Extensive Air Showers (EAS induced Cherenkov and fluorescent light, or radio waves. Moreover, all cosmic ray measurements (performed either from space or ground rely on accurate understandings of atmospheric phenomena. The concept of the COSAT project is the inter-link between Astroparticle Physics, Remote Sensing and Atmospheric Environment, willing to investigate the energetic cosmic rays physical processes using the atmosphere as a detector in order to identify potential scientific niches in the field of space sciences. A short introduction on the current status and perspectives of the national partnership COSAT project will be given.

  1. The ExaVolt Antenna: A Large-Aperture, Balloon-embedded Antenna for Ultra-high Energy Particle Detection

    CERN Document Server

    Gorham, P W; Allison, P; Liewer, K M; Miki, C; Hill, B; Varner, G S

    2011-01-01

    We describe the scientific motivation, experimental basis, design methodology, and simulated performance of the ExaVolt Antenna (EVA) mission, and planned ultra-high energy (UHE) particle observatory under development for NASA's suborbital super-pressure balloon program in Antarctica. EVA will improve over ANITA's integrated totals - the current state-of-the-art in UHE suborbital payloads - by 1-2 orders of magnitude in a single flight. The design is based on a novel application of toroidal reflector optics which utilizes a super-pressure balloon surface, along with a feed-array mounted on an inner membrane, to create an ultra-large radio antenna system with a synoptic view of the Antarctic ice sheet below it. Radio impulses arise via the Askaryan effect when UHE neutrinos interact within the ice, or via geosynchrotron emission when UHE cosmic rays interact in the atmosphere above the continent. EVA's instantaneous antenna aperture is estimated to be several hundred square meters for detection of these events...

  2. Extended clustering analyses to constrain the deflection angular scale and source density of the ultra-high-energy cosmic rays

    CERN Document Server

    Decerprit, Guillaume; Parizot, Etienne

    2011-01-01

    The search of a clustering signal in the arrival directions of ultra-high-energy cosmic rays (UHECRs) is a standard method to assess the level of anisotropy of the data sets under investigation. Here, we first show how to quantify the sensitivity of a UHECR detector to the detection of anisotropy, and then propose a new method that pushes forward the study of the two-point auto-correlation function, enabling one to put astrophysically meaningful constraints on both the effective UHECR source density and the angular deflections that these charged particles suffer while they propagate through the galactic and intergalactic magnetic fields. We apply the method to simulated data sets obtained under various astrophysical conditions, and show how the input model parameters can be estimated through our analysis, introducing the notion of "clustering similarity" (between data sets), to which we give a precise statistical meaning. We also study how the constraining power of the method is influenced by the size of the ...

  3. Detection of ultra high energy neutrinos by IceCube: Sterile neutrino scenario

    CERN Document Server

    Rajpoot, Subhash; Wang, Hsi Ching

    2013-01-01

    The short-baseline neutrino oscillation experiments, the excess of radiation from the measurement of the cosmic microwave background radiation, the necessity of the nonbaryonic dark matter candidate and the depletion of the neutrino flux in IceCube all seem to hint at new physics beyond the standard model. An economical way to address these issues is to invoke the existence of sterile neutrinos. We present simple extensions of the standard model with sterile neutrinos and discuss the corresponding PMNS like neutrino flavor mixing matrix. The noteworthy features of the sterile neutrino scenario advocated here is that the lightest one is almost degenerate with one of the active neutrinos, the second sterile has mass of order eV and the heaviest one is in the keV range. Our proposed mixing matrix is also compatible with the observed neutrino oscillation data. We show that the high energy muon and the tau neutrino fluxes from Gamma Ray Bursts can be depleted in IceCube by as much as 38% and 26% respectively. Thes...

  4. Testing large-scale (an)isotropy of ultra-high energy cosmic rays

    CERN Document Server

    Koers, Hylke B J

    2008-01-01

    We present a simple yet powerful method to test models of cosmic-ray (CR) origin using the distribution of CR arrival directions. The method is statistically unambiguous in the sense that it is binless and does not invoke scanning over unknown parameters, and general in the sense that it can be applied to any model that predicts a continuous distribution of CRs over the sky. We show that it provides a powerful discrimination between an isotropic distribution and predictions from the "matter tracer" model, a benchmark model that assumes small CR deflections and a continuous distribution of sources tracing the distribution of matter in the Universe. Our method is competitive or superior in statistical power to existing methods, and is especially sensitive in the case of relatively few high energy events. Applying the method to the present data we find that neither an isotropic distribution nor the matter tracer model can be excluded. Based on estimates of its statistical power, we expect that the proposed test ...

  5. Collider Experiment with Kerr Naked Singularities to probe Ultra-high Energy Physics

    CERN Document Server

    Patil, Mandar

    2011-01-01

    We investigate here the particle acceleration by Kerr naked singularities and propose an efficient mechanism to construct a collider experiment to study the beyond standard model physics all the way upto Planck scale, in their environment. In this work we show that the center of mass energy of collision between two particles, dropped in from a finite but arbitrary large distance along the axis of symmetry,is arbitrarily large, provided the deviation of the angular momentum parameter from the mass is very small for a Kerr naked singularity. The collisions considered here are between particles, one of them ingoing and the other one being initially an ingoing particle, which later emerges as an outgoing particle, after it suffers a reflection from a spatial region with repulsive gravity in the vicinity of the naked singularity. The chosen location for collisions marks a transition between attractive and repulsive regimes of gravity. Thus we argue that this would be an ideal site for the construction of a particl...

  6. Ultra high-energy neutrinos via heavy-meson synchrotron emission in strong magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, Toshitaka; Tokuhisa, Akira; Mathews, Grant J. [National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Yoshida, Takashi [Yukawa Institute of Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Famiano, Michael A. [Physics Department, Western Michigan University, 1903 W. Michigan Avenue, Kalamazoo, MI 49008-5252 (United States)

    2014-02-20

    We explore the generation and possibility for the detection of heavy-meson synchrotron emission due to the acceleration of ultra-relativistic protons (and possibly nuclei) in the presence of strong magnetic fields (H ≳ 10{sup 15} G) in transient astrophysical environments such as magnetar flares. We show that, in addition to the well-known pion synchrotron emission, heavy vector mesons like ρ, D{sub S} , J/Ψ, and Y could be generated. For high enough energies and magnetic field strengths, such heavy vector mesons can be formed with high intensity (∼10{sup 3} times the photon intensity) through strong couplings to the ultra-relativistic nucleons. We examine in particular the synchrotron emission and subsequent cooling and decay of the heavy ρ{sup 0} and Y(1S) mesons, e.g., via p → p' + Y(1S), Y(1S) → τ{sup +} + τ{sup –}, τ{sup −}→μ{sup −}+ ν-bar {sub μ}+ν{sub τ} and e{sup −}+ ν-bar {sub e}+ν{sub τ}. We evaluate the spectra of escaping ν {sub e}, ν{sub μ}, and ν{sub τ} due to the decay of short-lived τ mesons. We deduce the possible event rate in a terrestrial TeV neutrino detector. We estimate that neutrinos produced from the heavy vector-meson synchrotron radiation from a strong magnetar soft gamma repeater burst will only be detectable with the current generation of detectors if the source is very nearby (<30 pc). Nevertheless, if ever detected, the existence of heavy meson synchrotron emission might be identifiable by the unique signature of energetic tau neutrinos emanating from the source.

  7. Monte Carlo simulation for radio detection of Ultra High Energy air shower cores by ANITA-II

    Science.gov (United States)

    Javaid, Amir

    ANITA is a balloon borne radio interferometer, originally built for detection of Ultra High Energy (UHE) neutrinos through Askaryan pulses induced by neutrinos in the deep ice. Besides searching for neutrinos, ANITA has successfully detected geomagnetic radiation from UHE cosmic ray air showers. The present work checks for the possibility of an additional method of UHE cosmic ray detection by ANITA. Highly vertical showers have shower maximum near the ice surface in Antarctica. The compact cores of these shower produce particle cascades inside the ice and consequently Askaryan radio pulses which may be detected by ANITA. A new Monte Carlo simulation SAM (SADE ANITA Monte Carlo) was developed to study this process. SAM includes a full ANITA instrument and flight model as well as two unique components required for the cosmic ray core simulation. 1) A simple model for radio emission by core initiated cascades in the Antarctic firn, including scaling of the RF emission with the shower and medium properties and a CORSIKA derived parametrization for the energy contained inside the core. 2) Due to the different event geometry, cosmic ray core induced RF signals are reflected from the bedrock and suffer more attenuation than the neutrino induced signals. Accordingly a Pan- Antarctic geo-statistical frequency dependent 3D RF attenuation model was developed based on temperature, chemistry and other physical properties of Antarctic ice. Using the aperture determined from SAM, an Auger UHE cosmic ray flux is expected to produce 7.4×10 -4 < 0.13 < 0.44 events during an ANITA-II flight exposure. There are considerable uncertainties in this estimate.

  8. BLAZARS AS ULTRA-HIGH-ENERGY COSMIC-RAY SOURCES: IMPLICATIONS FOR TeV GAMMA-RAY OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Murase, Kohta [Department of Physics, Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Dermer, Charles D. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Takami, Hajime [Max Planck Institute for Physics, Foehringer Ring 6, 80805 Munich (Germany); Migliori, Giulia [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2012-04-10

    The spectra of BL Lac objects and Fanaroff-Riley I radio galaxies are commonly explained by the one-zone leptonic synchrotron self-Compton (SSC) model. Spectral modeling of correlated multiwavelength data gives the comoving magnetic field strength, the bulk outflow Lorentz factor, and the emission region size. Assuming the validity of the SSC model, the Hillas condition shows that only in rare cases such sources accelerate protons to much above 10{sup 19} eV, so {approx}> 10{sup 20} eV ultra-high-energy cosmic rays (UHECRs) are likely to be heavy ions if powered by this type of radio-loud active galactic nuclei (AGNs). Survival of nuclei is shown to be possible in TeV BL Lacs and misaligned counterparts with weak photohadronic emissions. Another signature of hadronic production is intergalactic UHECR-induced cascade emission, which is an alternative explanation of the TeV spectra of some extreme non-variable blazars such as 1ES 0229+200 or 1ES 1101-232. We study this kind of cascade signal, taking into account effects of the structured extragalactic magnetic fields in which the sources should be embedded. We demonstrate the importance of cosmic-ray deflections on the {gamma}-ray flux, and show that required absolute cosmic-ray luminosities are larger than the average UHECR luminosity inferred from UHECR observations and can even be comparable to the Eddington luminosity of supermassive black holes. Future TeV {gamma}-ray observations using the Cerenkov Telescope Array and the High Altitude Water Cerenkov detector array can test for UHECR acceleration by observing >25 TeV photons from relatively low redshift sources such as 1ES 0229+200, and {approx}>TeV photons from more distant radio-loud AGNs.

  9. The Energy Spectrum of Ultra-High-Energy Cosmic Rays Measured by the Telescope Array FADC Fluorescence Detectors in Monocular Mode

    CERN Document Server

    Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Cheon, B G; Chiba, J; Chikawa, M; Cho, E J; Cho, W R; Fujii, H; Fujii, T; Fukuda, T; Fukushima, M; Hanlon, W; Hayashi, K; Hayashi, Y; Hayashida, N; Hibino, K; Hiyama, K; Honda, K; Iguchi, T; Ikeda, D; Ikuta, K; Inoue, N; Ishii, T; Ishimori, R; Ito, H; Ivanov, D; Iwamoto, S; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kanbe, T; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kido, E; Kim, H B; Kim, H K; Kim, J H; Kitamoto, K; Kitamura, S; Kitamura, Y; Kobayashi, K; Kobayashi, Y; Kondo, Y; Kuramoto, K; Kuzmin, V; Kwon, Y J; Lan, J; Lim, S I; Lundquist, J P; Machida, S; Martens, K; Matsuda, T; Matsuura, T; Matsuyama, T; Matthews, J N; Myers, I; Minamino, M; Miyata, K; Murano, Y; Nagataki, S; Nakamura, T; Nam, S W; Nonaka, T; Ogio, S; Ogura, J; Ohnishi, M; Ohoka, H; Oki, K; Oku, D; Okuda, T; Ono, M; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Roh, S Y; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, J I; Shirahama, T; Smith, J D; Sokolsky, P; Sonley, T J; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T A; Suzuki, S; Takahashi, Y; Takeda, M; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Tsuyuguchi, Y; Uchihori, Y; Udo, S; Ukai, H; Vasiloff, G; Wada, Y; Wong, T; Yamakawa, Y; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yoneda, Y; Yoshida, S; Yoshii, H; Zollinger, R; Zundel, Z

    2013-01-01

    We present a measurement of the energy spectrum of ultra-high-energy cosmic rays performed by the Telescope Array experiment using monocular observations from its two new FADC-based fluorescence detectors. After a short description of the experiment, we describe the data analysis and event reconstruction procedures. Since the aperture of the experiment must be calculated by Monte Carlo simulation, we describe this calculation and the comparisons of simulated and real data used to verify the validity of the aperture calculation. Finally, we present the energy spectrum calculated from the merged monocular data sets of the two FADC-based detectors, and also the combination of this merged spectrum with an independent, previously published monocular spectrum measurement performed by Telescope Array's third fluorescence detector (Abu-Zayyad {\\it et al.}, {Astropart. Phys.} 39 (2012), 109). This combined spectrum corroborates the recently published Telescope Array surface detector spectrum (Abu-Zayyad {\\it et al.}, ...

  10. Constraints on secondary 10-100 EeV gamma ray flux in the minimal bottom-up model of Ultra High Energy Cosmic Rays

    CERN Document Server

    Kalashev, O; Semikoz, Dmitry V

    2007-01-01

    In a recently proposed model the cosmic rays spectrum at energies above EeV can be fitted with a minimal number of unknown parameters assuming that the extragalactic cosmic rays are only protons with a power law source spectrum. Within this minimal model, after fitting the observed HiRes spectrum with four parameters (proton injection spectrum power law index, maximum energy, minimum distance to sources and evolution parameter) we compute the flux of ultra-high energy photons due to photon-pion production and e+e- pair production by protons for several radio background models and a range of average extragalactic magnetic fields.

  11. Constraining Dark Matter and Ultra-High Energy Cosmic Ray Sources with Fermi-LAT Diffuse Gamma Ray Background

    CERN Document Server

    Kalashev, Oleg

    2016-01-01

    We use the recent measurement of the isotropic $\\gamma$-ray background (IGRB) by Fermi LAT and analysis of the contribution of unresolved point $\\gamma$-ray sources to IGRB to build constraints on the models of ultra-high cosmic rays (UHECR) origin. We also calculate the minimal expected diffuse $\\gamma$-ray flux produced by UHECR interactions with an interstellar photon background. Finally, for the subclass of dark matter (DM) models with decaying weakly interacting massive particles (WIMP), we build constraints on the particle decay time using minimal expected contributions to the IGRB from unresolved point $\\gamma$-ray sources and UHECR.

  12. Energy Spectrum of Ultra-High Energy Cosmic Rays Observed with the Telescope Array Using a Hybrid Technique

    CERN Document Server

    Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Cheon, B G; Chiba, J; Chikawa, M; Cho, E J; Cho, W R; Fujii, H; Fujii, T; Fukuda, T; Fukushima, M; Hanlon, W; Hayashi, K; Hayashi, Y; Hayashida, N; Hibino, K; Hiyama, K; Honda, K; Iguchi, T; Ikeda, D; Ikuta, K; Inoue, N; Ishii, T; Ishimori, R; Ito, H; Ivanov, D; Iwamoto, S; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kanbe, T; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kido, E; Kim, H B; Kim, H K; Kim, J H; Kitamoto, K; Kitamura, S; Kitamura, Y; Kobayashi, K; Kobayashi, Y; Kondo, Y; Kuramoto, K; Kuzmin, V; Kwon, Y J; Lan, J; Lim, S I; Lundquist, J P; Machida, S; Martens, K; Matsuda, T; Matsuura, T; Matsuyama, T; Matthews, J N; Minamino, M; Miyata, K; Murano, Y; Myers, I; Nagasawa, K; Nagataki, S; Nakamura, T; Nam, S W; Nonaka, T; Ogio, S; Ohnishi, M; Ohoka, H; Oki, K; Oku, D; Okuda, T; Ono, M; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Roh, S Y; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, J I; Shirahama, T; Smith, J D; Sokolsky, P; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T; Suzuki, S; Takahashi, Y; Takeda, M; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Tsuyuguchi, Y; Uchihori, Y; Udo, S; Ukai, H; Urban, F; Vasiloff, G; Wada, Y; Wong, T; Yamakawa, Y; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yoneda, Y; Yoshida, S; Yoshii, H; Zhou, X; Zollinger, R; Zundel, Z

    2013-01-01

    We measure the spectrum of cosmic rays with energies greater than $10^{18.2}$ eV with the Fluorescence Detectors (FDs) and the Surface Detectors (SDs) of the Telescope Array Experiment using the data taken in our first 2.3-year observation from May 27 2008 to September 7 2010. A hybrid air shower reconstruction technique is employed to improve accuracies in determination of arrival directions and primary energies of cosmic rays using both FD and SD data. The energy spectrum presented here is in agreement with our previously published spectra and the HiRes results.

  13. First results from the microwave air yield beam experiment (MAYBE: Measurement of GHz radiation for ultra-high energy cosmic ray detection

    Directory of Open Access Journals (Sweden)

    Verzi V.

    2013-06-01

    Full Text Available We present measurements of microwave emission from an electron-beam induced air plasma performed at the 3 MeV electron Van de Graaff facility of the Argonne National Laboratory. Results include the emission spectrum between 1 and 15 GHz, the polarization of the microwave radiation and the scaling of the emitted power with respect to beam intensity. MAYBE measurements provide further insight on microwave emission from extensive air showers as a novel detection technique for Ultra-High Energy Cosmic Rays.

  14. Ultra high energy density nanocomposite capacitors with fast discharge using Ba0.2Sr0.8TiO3 nanowires.

    Science.gov (United States)

    Tang, Haixiong; Sodano, Henry A

    2013-04-10

    Nanocomposites combining a high breakdown strength polymer and high dielectric permittivity ceramic filler have shown great potential for pulsed power applications. However, while current nanocomposites improve the dielectric permittivity of the capacitor, the gains come at the expense of the breakdown strength, which limits the ultimate performance of the capacitor. Here, we develop a new synthesis method for the growth of barium strontium titanate nanowires and demonstrate their use in ultra high energy density nanocomposites. This new synthesis process provides a facile approach to the growth of high aspect ratio nanowires with high yield and control over the stoichiometry of the solid solution. The nanowires are grown in the cubic phase with a Ba0.2Sr0.8TiO3 composition and have not been demonstrated prior to this report. The poly(vinylidene fluoride) nanocomposites resulting from this approach have high breakdown strength and high dielectric permittivity which results from the use of high aspect ratio fillers rather than equiaxial particles. The nanocomposites are shown to have an ultra high energy density of 14.86 J/cc at 450 MV/m and provide microsecond discharge time quicker than commercial biaxial oriented polypropylene capacitors. The energy density of our nanocomposites exceeds those reported in the literature for ceramic/polymer composites and is 1138% greater than the reported commercial capacitor with energy density of 1.2 J/cc at 640 MV/m for the current state of the art biaxial oriented polypropylene.

  15. On Gamma Ray Burst and Blazar AGN Origins of the Ultra-High Energy Cosmic Rays in Light of First Results from Auger

    CERN Document Server

    Dermer, Charles D

    2007-01-01

    The discoveries of the GZK cutoff with the HiRes and Auger Observatories and the discovery by Auger of clustering of >~60 EeV ultra-high energy cosmic rays (UHECRs) towards nearby <~75 Mpc) AGNs along the supergalactic plane establishes the astrophysical origin of the UHECRs. The likely sources of the UHECRs are gamma-ray bursts and radio-loud AGNs because: (1) they are extragalactic; (2) they are sufficiently powerful; (3) acceleration to ultra-high energies can be achieved in their relativistic ejecta; (4) anomalous X-ray and $\\gamma$-ray features can be explained by nonthermal hadron acceleration in relativistic blast waves; and (5) sources reside within the GZK radius. Two arguments for acceleration to UHE are presented, and limits on UHECR ion acceleration are set. UHECR ions are shown to be able to survive without photodisintegrating while passing through the AGN scattered radiation field, even if launched deep in the broad line region. UHECR injection throughout cosmic time fits the measured energy ...

  16. Ultra high resolution tomography

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, W.S.

    1994-11-15

    Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

  17. A compact Ultra-High Vacuum (UHV) compatible instrument for time of flight-energy measurements of slow heavy reaction products

    CERN Document Server

    Kuznetsov, A V; Westerberg, L; Lyapin, V G; Aleklett, K; Loveland, W; Bondorf, J P; Jakobsson, B; Whitlow, H J; El-Bouanani, M

    2000-01-01

    A compact Ultra-High Vacuum (UHV) compatible instrument for time of flight-energy measurements of slow heavy reaction products from nuclear reactions has been designed and tested at the CELSIUS storage ring in Uppsala. The construction is based on MicroChannel Plate (MCP) time detectors of the electron mirror type and silicon p-i-n diodes, and permits the detectors to be stacked side-by-side to achieve large solid angle coverage. This kind of telescope measures the Time of Flight (ToF) and Energy (E) of the particle from which one can reconstruct mass. The combination of an ultra-thin cluster gas-jet target and thin carbon emitter foils allows one to measure heavy residues down to an energy of approx 35 keV/nucleon from the interactions of 400 MeV/nucleon sup 1 sup 6 O with sup n sup a sup t Xe gas targets.

  18. Search for correlations of the arrival directions of ultra-high energy cosmic ray with extragalactic objects as observed by the telescope array experiment

    CERN Document Server

    Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Cheon, B G; Chiba, J; Chikawa, M; Cho, E J; Cho, W R; Fujii, H; Fujii, T; Fukuda, T; Fukushima, M; Hanlon, W; Hayashi, K; Hayashi, Y; Hayashida, N; Hibino, K; Hiyama, K; Honda, K; Iguchi, T; Ikeda, D; Ikuta, K; Inoue, N; Ishii, T; Ishimori, R; Ito, H; Ivanov, D; Iwamoto, S; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kanbe, T; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kido, E; Kim, H B; Kim, H K; Kim, J H; Kitamoto, K; Kitamura, S; Kitamura, Y; Kobayashi, K; Kobayashi, Y; Kondo, Y; Kuramoto, K; Kuzmin, V; Kwon, Y J; Lan, J; Lim, S I; Lundquist, J P; Machida, S; Martens, K; Matsuda, T; Matsuura, T; Matsuyama, T; Matthews, J N; Minamino, M; Miyata, K; Murano, Y; Myers, I; Nagasawa, K; Nagataki, S; Nakamura, T; Nam, S W; Nonaka, T; Ogio, S; Ohnishi, M; Ohoka, H; Oki, K; Oku, D; Okuda, T; Ono, M; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Roh, S Y; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, J I; Shirahama, T; Smith, J D; Sokolsky, P; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T; Suzuki, S; Takahashi, Y; Takeda, M; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Tsuyuguchi, Y; Uchihori, Y; Udo, S; Ukai, H; Urban, F; Vasiloff, G; Wada, Y; Wong, T; Yamakawa, Y; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yoneda, Y; Yoshida, S; Yoshii, H; Zhou, X; Zollinger, R; Zundel, Z

    2013-01-01

    We search for correlations between positions of extragalactic objects and arrival directions of Ultra-High Energy Cosmic Rays (UHECRs) with primary energy $E \\ge 40$ EeV as observed by the surface detector array of the Telescope Array (TA) experiment during the first 40 months of operation. We examined several public astronomical object catalogs, including the Veron-Cetty and Veron catalog of active galactic nuclei. We counted the number of TA events correlated with objects in each catalog as a function of three parameters: the maximum angular separation between a TA event and an object, the minimum energy of the events, and the maximum redshift of the objects. We determine combinations of these parameters which maximize the correlations, and calculate the chance probabilities of having the same levels of correlations from an isotropic distribution of UHECR arrival directions. No statistically significant correlations are found when penalties for scanning over the above parameters and for searching in several...

  19. Mass composition studies of Ultra High Energy cosmic rays through the measurement of the Muon Production Depths at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Collica, Laura [Univ. of Milan (Italy); Paris Diderot Univ. (France)

    2014-01-01

    The Pierre Auger Observatory (Auger) in Argentina studies Ultra High Energy Cosmic Rays (UHECRs) physics. The flux of cosmic rays at these energies (above 1018 eV) is very low (less than 100 particle/km2-year) and UHECR properties must be inferred from the measurements of the secondary particles that the cosmic ray primary produces in the atmosphere. These particles cascades are called Extensive Air Showers (EAS) and can be studied at ground by deploying detectors covering large areas. The EAS physics is complex, and the properties of secondary particles depend strongly on the first interaction, which takes place at an energy beyond the ones reached at accelerators. As a consequence, the analysis of UHECRs is subject to large uncertainties and hence many of their properties, in particular their composition, are still unclear. Two complementary techniques are used at Auger to detect EAS initiated by UHE- CRs: a 3000 km2 surface detector (SD) array of water Cherenkov tanks which samples particles at ground level and fluorescence detectors (FD) which collect the ultraviolet light emitted by the de-excitation of nitrogen nuclei in the atmosphere, and can operate only in clear, moonless nights. Auger is the largest cosmic rays detector ever built and it provides high-quality data together with unprecedented statistics. The main goal of this thesis is the measurement of UHECR mass composition using data from the SD of the Pierre Auger Observatory. Measuring the cosmic ray composition at the highest energies is of fundamental importance from the astrophysical point of view, since it could discriminate between different scenarios of origin and propagation of cosmic rays. Moreover, mass composition studies are of utmost importance for particle physics. As a matter of fact, knowing the composition helps in exploring the hadronic interactions at ultra-high energies, inaccessible to present accelerator experiments.

  20. Constraints on the Ultra-High Energy Neutrino Flux from Gamma-Ray Bursts from a Prototype Station of the Askaryan Radio Array

    CERN Document Server

    Allison, P; Bard, R; Beatty, J J; Besson, D Z; Bora, C; Chen, C -C; Chen, P; Connolly, A; Davies, J P; DuVernois, M A; Fox, B; Gorham, P W; Hanson, K; Hill, B; Hoffman, K D; Hong, E; Hu, L -C; Ishihara, A; Karle, A; Kelley, J; Kravchenko, I; Landsman, H; Laundrie, A; Li, C -J; Liu, T; Lu, M -Y; Maunu, R; Mase, K; Meures, T; Miki, C; Nam, J; Nichol, R J; Nir, G; O'Murchadha, A; Pfendner, C G; Ratzlaff, K; Richman, M; Rotter, B; Sandstrom, P; Seckel, D; Shultz, A; Song, M; Stockham, J; Stockham, M; Sullivan, M; Touart, J; Tu, H -Y; Varner, G S; Yoshida, S; Young, R; Guetta, D

    2015-01-01

    We searched for ultra-high energy (UHE) neutrinos from Gamma-Ray Bursts (GRBs) with the Askaryan Radio Array (ARA) Testbed station's 2011-2012 data set. Among 589 GRBs monitored by the Gamma Ray Coordinate Network (GCN) catalog from Jan. 2011 to Dec. 2012 over the entire sky, 57 GRBs were selected for analysis. These GRBs were chosen because they occurred during a period of low anthropogenic background and high stability of the station and fell within our geometric acceptance. We searched for UHE neutrinos from 57 GRBs and observed 0 events, which is consistent with 0.11 expected background events. With this result, we set the limits on the UHE GRB neutrino fluence and quasi-diffuse flux from $10^{16}$ to $10^{19}$~eV. This is the first limit on the UHE GRB neutrino quasi-diffuse flux at energies above $10^{16}$~eV.

  1. Inferring Average Ground Profiles of the Muon Density of Inclined Air Showers from Monte-Carlo Simulations at Ultra-High Energy

    CERN Document Server

    Dembinski, Hans; Deligny, Olivier; Hebbeker, Thomas

    2009-01-01

    A standard method to measure ultra-high energy cosmic rays is the sampling of the ground particle profile of the extensive air shower that is produced in the atmosphere with an array of surface detectors. The primary energy of inclined air showers with zenith angles >60 Deg can be reconstructed by using simulated 2-D profiles of the ground density of muons. We will present an effective way to extract such profiles from a library of Monte-Carlo simulated air showers. Also, we will demonstrate a way to speed up the simulation of ground profiles of the muon density in very inclined showers by three orders of magnitude, if only the muon component in the shower is of interest.

  2. Determination of the proton-to-helium ratio in cosmic rays at ultra-high energies from the tail of the Xmax distribution

    Science.gov (United States)

    Yushkov, A.; Risse, M.; Werner, M.; Krieg, J.

    2016-12-01

    We present a method to determine the proton-to-helium ratio in cosmic rays at ultra-high energies. It makes use of the exponential slope, Λ, of the tail of the Xmax distribution measured by an air shower experiment. The method is quite robust with respect to uncertainties from modeling hadronic interactions and to systematic errors on Xmax and energy, and to the possible presence of primary nuclei heavier than helium. Obtaining the proton-to-helium ratio with air shower experiments would be a remarkable achievement. To quantify the applicability of a particular mass-sensitive variable for mass composition analysis despite hadronic uncertainties we introduce as a metric the 'analysis indicator' and find an improved performance of the Λ method compared to other variables currently used in the literature. The fraction of events in the tail of the Xmax distribution can provide additional information on the presence of nuclei heavier than helium in the primary beam.

  3. Study of Ultra-High Energy Cosmic Ray Composition Using Telescope Array's Middle Drum Detector and Surface Array in Hybrid Mode

    CERN Document Server

    Abbasi, R U; Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Chae, M J; Cheon, B G; Chiba, J; Chikawa, M; Cho, W R; Fujii, T; Fukushima, M; Goto, T; Hanlon, W; Hayashi, Y; Hayashida, N; Hibino, K; Honda, K; Ikeda, D; Inoue, N; Ishii, T; Ishimori, R; Ito, H; Ivanov, D; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kawata, K; Kido, E; Kim, H B; Kim, J H; Kitamura, S; Kitamura, Y; Kuzmin, V; Kwon, Y J; Lan, J; Lim, S I; Lundquist, J P; Machida, K; Martens, K; Matsuda, T; Matsuyama, T; Matthews, J N; Minamino, M; Mukai, Y; Myers, I; Nagasawa, K; Nagataki, S; Nakamura, T; Nonaka, T; Nozato, A; Ogio, S; Ogura, J; Ohnishi, M; Ohoka, H; Oki, K; Okuda, T; Ono, M; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, H S; Smith, J D; Sokolsky, P; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T; Suzawa, T; Takamura, M; Takeda, M; Takeishi, R; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Uchihori, Y; Udo, S; Urban, F; Vasiloff, G; Wong, T; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yashiro, K; Yoneda, Y; Yoshida, S; Yoshiia, H; Zollinger, R; Zundel, Z

    2014-01-01

    Previous measurements of the composition of Ultra-High energy Cosmic Rays (UHECRs) made by the High Resolution Fly's Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory but utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in methodology to PAO, and good agreement is evident between data and a light, largely protonic composition using simulations from a variety of hadronic models for the comparison of both elongation rate and shower fluctuations. This is in good agreement with the HiRes results. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.

  4. Comprehensive metabolite profiling of Plantaginis Semen using ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry coupled with elevated energy technique.

    Science.gov (United States)

    Wang, Dandan; Qi, Meng; Yang, Qiming; Tong, Renchao; Wang, Rui; Bligh, S W Annie; Yang, Li; Wang, Zhengtao

    2016-05-01

    Plantaginis Semen is commonly used in traditional medicine to treat edema, hypertension, and diabetes. The commercially available Plantaginis Semen in China mainly comes from three species. To clarify the chemical composition and distinct different species of Plantaginis Semen, we established a metabolite profiling method based on ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry coupled with elevated energy technique. A total of 108 compounds, including phenylethanoid glycosides, flavonoids, guanidine derivatives, terpenoids, organic acids, and fatty acids, were identified from Plantago asiatica L., P. depressa Willd., and P. major L. Results showed significant differences in chemical components among the three species, particularly flavonoids. This study is the first to provide a comprehensive chemical profile of Plantaginis Semen, which could be involved into the quality control, medication guide, and developing new drug of Plantago seeds.

  5. Constraints on the ultra-high-energy neutrino flux from Gamma-Ray bursts from a prototype station of the Askaryan radio array

    Science.gov (United States)

    Allison, P.; Auffenberg, J.; Bard, R.; Beatty, J. J.; Besson, D. Z.; Bora, C.; Chen, C.-C.; Chen, P.; Connolly, A.; Davies, J. P.; DuVernois, M. A.; Fox, B.; Gorham, P. W.; Hanson, K.; Hill, B.; Hoffman, K. D.; Hong, E.; Hu, L.-C.; Ishihara, A.; Karle, A.; Kelley, J.; Kravchenko, I.; Landsman, H.; Laundrie, A.; Li, C.-J.; Liu, T.; Lu, M.-Y.; Maunu, R.; Mase, K.; Meures, T.; Miki, C.; Nam, J.; Nichol, R. J.; Nir, G.; Ó Murchadha, A.; Pfendner, C. G.; Ratzlaff, K.; Rotter, B.; Sandstrom, P.; Seckel, D.; Shultz, A.; Song, M.; Stockham, J.; Stockham, M.; Sullivan, M.; Touart, J.; Tu, H.-Y.; Varner, G. S.; Yoshida, S.; Young, R.; Bustamante, M.; Guetta, D.

    2017-02-01

    We report on a search for ultra-high-energy (UHE) neutrinos from gamma-ray bursts (GRBs) in the data set collected by the Testbed station of the Askaryan Radio Array (ARA) in 2011 and 2012. From 57 selected GRBs, we observed no events that survive our cuts, which is consistent with 0.12 expected background events. Using NeuCosmA as a numerical GRB reference emission model, we estimate upper limits on the prompt UHE GRB neutrino fluence and quasi-diffuse flux from 107 to 1010 GeV. This is the first limit on the prompt UHE GRB neutrino quasi-diffuse flux above 107 GeV.

  6. Constraints on ultra-high-energy cosmic ray sources from a search for neutrinos above 10 PeV with IceCube

    CERN Document Server

    Aartsen, M G; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Ahrens, M; Altmann, D; Andeen, K; Anderson, T; Ansseau, I; Anton, G; Archinger, M; Argüelles, C; Auffenberg, J; Axani, S; Bai, X; Barwick, S W; Baum, V; Bay, R; Beatty, J J; Tjus, J Becker; Becker, K -H; BenZvi, S; Berghaus, P; Berley, D; Bernardini, E; Bernhard, A; Besson, D Z; Binder, G; Bindig, D; Bissok, M; Blaufuss, E; Blot, S; Bohm, C; Börner, M; Bos, F; Bose, D; Böser, S; Botner, O; Braun, J; Brayeur, L; Bretz, H -P; Burgman, A; Carver, T; Casier, M; Cheung, E; Chirkin, D; Christov, A; Clark, K; Classen, L; Coenders, S; Collin, G H; Conrad, J M; Cowen, D F; Cross, R; Day, M; de André, J P A M; De Clercq, C; Rosendo, E del Pino; Dembinski, H; De Ridder, S; Desiati, P; de Vries, K D; de Wasseige, G; de With, M; DeYoung, T; Díaz-Vélez, J C; di Lorenzo, V; Dujmovic, H; Dumm, J P; Dunkman, M; Eberhardt, B; Ehrhardt, T; Eichmann, B; Eller, P; Euler, S; Evenson, P A; Fahey, S; Fazely, A R; Feintzeig, J; Felde, J; Filimonov, K; Finley, C; Flis, S; Fösig, C -C; Franckowiak, A; Friedman, E; Fuchs, T; Gaisser, T K; Gallagher, J; Gerhardt, L; Ghorbani, K; Giang, W; Gladstone, L; Glagla, M; Glüsenkamp, T; Goldschmidt, A; Golup, G; Gonzalez, J G; Grant, D; Griffith, Z; Haack, C; Ismail, A Haj; Hallgren, A; Halzen, F; Hansen, E; Hansmann, B; Hansmann, T; Hanson, K; Hebecker, D; Heereman, D; Helbing, K; Hellauer, R; Hickford, S; Hignight, J; Hill, G C; Hoffman, K D; Hoffmann, R; Holzapfel, K; Hoshina, K; Huang, F; Huber, M; Hultqvist, K; In, S; Ishihara, A; Jacobi, E; Japaridze, G S; Jeong, M; Jero, K; Jones, B J P; Jurkovic, M; Kappes, A; Karg, T; Karle, A; Katz, U; Kauer, M; Keivani, A; Kelley, J L; Kemp, J; Kheirandish, A; Kim, M; Kintscher, T; Kiryluk, J; Kittler, T; Klein, S R; Kohnen, G; Koirala, R; Kolanoski, H; Konietz, R; Köpke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Krings, K; Kroll, M; Krückl, G; Krüger, C; Kunnen, J; Kunwar, S; Kurahashi, N; Kuwabara, T; Labare, M; Lanfranchi, J L; Larson, M J; Lauber, F; Lennarz, D; Lesiak-Bzdak, M; Leuermann, M; Leuner, J; Lu, L; Lünemann, J; Madsen, J; Maggi, G; Mahn, K B M; Mancina, S; Mandelartz, M; Maruyama, R; Mase, K; Maunu, R; McNally, F; Meagher, K; Medici, M; Meier, M; Meli, A; Menne, T; Merino, G; Meures, T; Miarecki, S; Mohrmann, L; Montaruli, T; Moulai, M; Nahnhauer, R; Naumann, U; Neer, G; Niederhausen, H; Nowicki, S C; Nygren, D R; Pollmann, A Obertacke; Olivas, A; O'Murchadha, A; Palczewski, T; Pandya, H; Pankova, D V; Peiffer, P; Penek, Ö; Pepper, J A; Heros, C Pérez de los; Pieloth, D; Pinat, E; Price, P B; Przybylski, G T; Quinnan, M; Raab, C; Rädel, L; Rameez, M; Rawlins, K; Reimann, R; Relethford, B; Relich, M; Resconi, E; Rhode, W; Richman, M; Riedel, B; Robertson, S; Rongen, M; Rott, C; Ruhe, T; Ryckbosch, D; Rysewyk, D; Sabbatini, L; Herrera, S E Sanchez; Sandrock, A; Sandroos, J; Sarkar, S; Satalecka, K; Schimp, M; Schlunder, P; Schmidt, T; Schoenen, S; Schöneberg, S; Schumacher, L; Seckel, D; Seunarine, S; Soldin, D; Song, M; Spiczak, G M; Spiering, C; Stahlberg, M; Stanev, T; Stasik, A; Steuer, A; Stezelberger, T; Stokstad, R G; Stößl, A; Ström, R; Strotjohann, N L; Sullivan, G W; Sutherland, M; Taavola, H; Taboada, I; Tatar, J; Tenholt, F; Ter-Antonyan, S; Terliuk, A; Tešić, G; Tilav, S; Toale, P A; Tobin, M N; Toscano, S; Tosi, D; Tselengidou, M; Turcati, A; Unger, E; Usner, M; Vandenbroucke, J; van Eijndhoven, N; Vanheule, S; van Rossem, M; van Santen, J; Veenkamp, J; Vehring, M; Voge, M; Vraeghe, M; Walck, C; Wallace, A; Wallraff, M; Wandkowsky, N; Weaver, Ch; Weiss, M J; Wendt, C; Westerhoff, S; Whelan, B J; Wickmann, S; Wiebe, K; Wiebusch, C H; Wille, L; Williams, D R; Wills, L; Wolf, M; Wood, T R; Woolsey, E; Woschnagg, K; Xu, D L; Xu, X W; Xu, Y; Yanez, J P; Yodh, G; Yoshida, S; Zoll, M

    2016-01-01

    We report constraints on the sources of ultra-high-energy cosmic ray (UHECR) above $10^{9}$ GeV, based on an analysis of seven years of IceCube data. This analysis efficiently selects very high energy neutrino-induced events which have deposited energies from $\\sim 10^6$ GeV to above $10^{11}$ GeV. Two neutrino-induced events with an estimated deposited energy of $(2.6 \\pm 0.3) \\times 10^6$ GeV, the highest neutrino energies observed so far, and $(7.7 \\pm 2.0) \\times 10^5$ GeV were detected. The atmospheric background-only hypothesis of detecting these events is rejected at 3.6$\\sigma$. The hypothesis that the observed events are of cosmogenic origin is also rejected at $>$99% CL because of the limited deposited energy and the non-observation of events at higher energy, while their observation is consistent with an astrophysical origin. Our limits on cosmogenic neutrino fluxes disfavor the UHECR sources having cosmological evolution stronger than the star formation rate, e.g., active galactic nuclei and $\\gam...

  7. The all-diode-pumped laser system POLARIS——an experimentalist’s tool generating ultra-high contrast pulses with high energy

    Institute of Scientific and Technical Information of China (English)

    Marco; Hornung; Hartmut; Liebetrau; Andreas; Seidel; Sebastian; Keppler; Alexander; Kessler; Jrg; Krner; Marco; Hellwing; Frank; Schorcht; Diethard; Klpfel; Ajay; K.Arunachalam; Georg; A.Becker; Alexander; Svert; Jens; Polz; Joachim; Hein; Malte; C.Kaluza

    2014-01-01

    The development,the underlying technology and the current status of the fully diode-pumped solid-state laser system POLARIS is reviewed.Currently,the POLARIS system delivers 4 J energy,144 fs long laser pulses with an ultra-high temporal contrast of 5 × 1012 for the ASE,which is achieved using a so-called double chirped-pulse amplification scheme and cross-polarized wave generation pulse cleaning.By tightly focusing,the peak intensity exceeds 3.5 × 1020 W cm-2.These parameters predestine POLARIS as a scientific tool well suited for sophisticated experiments,as exemplified by presenting measurements of accelerated proton energies.Recently,an additional amplifier has been added to the laser chain.In the ramp-up phase,pulses from this amplifier are not yet compressed and have not yet reached the anticipated energy.Nevertheless,an output energy of 16.6 J has been achieved so far.

  8. Search for Diffuse Astrophysical Neutrino Flux Using Ultra-High Energy Upward-Going Muons in Super-Kamiokande I

    CERN Document Server

    Swanson, M E C; Hosaka, J; Iida, T; Ishihara, K; Kameda, J; Koshio, Y; Minamino, A; Mitsuda, C; Miura, M; Moriyama, S; Nakahata, M; Obayashi, Y; Ogawa, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takeuchi, Y; Ueshima, K; Higuchi, I; Ishihara, C; Ishitsuka, M; Kajita, T; Kaneyuki, K; Mitsuka, G; Nakayama, S; Nishino, H; Okada, A; Okumura, K; Saji, C; Takenaga, Y; Clark, S; Desai, S; Dufour, F; Kearns, E; Likhoded, S; Litos, M; Raaf, Jennifer L; Stone, J L; Sulak, L R; Wang, W; Goldhaber, M; Casper, D; Cravens, J P; Dunmore, J; Kropp, W R; Liu, D W; Mine, S; Regis, C; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Hill, J E; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Scholberg, K; Tanimoto, N; Walter, C W; Wendell, R; Ellsworth, R W; Tasaka, S; Guillian, G; Learned, J G; Matsuno, S; Messier, M D; Hayato, Y; Ichikawa, A K; Ishida, T; Ishii, T; Iwashita, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nitta, K; Oyama, Y; Totsuka, Y; Suzuki, A T; Hasegawa, M; Hiraide, K; Kato, I; Maesaka, H; Nakaya, T; Nishikawa, K; Sasaki, T; Sato, H; Yamamoto, S; Yokoyama, M; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Sullivan, G W; Turcan, D; Cooley, J; Mahn, K B M; Habig, A; Fukuda, Y; Sato, T; Itow, Y; Koike, T; Jung, C K; Kato, T; Kobayashi, K; Malek, M; McGrew, C; Sarrat, A; Terri, R; Yanagisawa, C; Tamura, N; Sakuda, M; Sugihara, M; Kuno, Y; Yoshida, M; Kim, S B; Yang, B S; Yoo, J; Ishizuka, T; Okazawa, H; Choi, Y; Seo, H K; Gando, Y; Hasegawa, T; Inoue, K; Ishii, H; Nishijima, K; Ishino, H; Watanabe, Y; Koshiba, M; Kielczewska, D; Zalipska, J; Berns, H G; Gran, R; Shiraishi, K K; Stachyra, A; Thrane, E; Washburn, K; Wilkes, R J002626770 100 L; Adams, J

    2006-01-01

    Many astrophysical models predict a diffuse flux of high energy neutrinos from active galactic nuclei and other extra-galactic sources. At muon energies above a TeV, the upward-going muon flux induced by neutrinos from active galactic nuclei is expected to exceed the flux due to atmospheric neutrinos. We have performed a search for this astrophysical neutrino flux by looking for upward-going muons in the highest energy data sample from the Super-Kamiokande detector using 1679.6 live days of data. We found 1 extremely high energy upward-going muon event, compared with an expected atmospheric neutrino background of 0.46 plus or minus 0.23 events. Using this result, we set an upper limit on the diffuse flux of upward-going muons due to neutrinos from astrophysical sources in the muon energy range 3.16-100 TeV.

  9. Measurement of a Phase of a Radio Wave Reflected from Rock Salt and Ice Irradiated by an Electron Beam for Detection of Ultra-High-Energy Neutrinos

    CERN Document Server

    Chiba, Masami; Tanikawa, Takahiro; Yano, Hiroyuki; Yabuki, Fumiaki; Yasuda, Osamu; Chikashige, Yuichi; Kon, Tadashi; Shimizu, Yutaka; Watanabe, Souichirou; Utsumi, Michiaki; Fujii, Masatoshi

    2013-01-01

    We have found a radio-wave-reflection effect in rock salt for the detection of ultra-high energy neutrinos which are expected to be generated in Greisen, Zatsepin, and Kuzmin (GZK) processes in the universe. When an UHE neutrino interacts with rock salt or ice as a detection medium, a shower is generated. That shower is formed by hadronic and electromagnetic avalanche processes. The energy of the UHE neutrino shower converts to thermal energy through ionization processes. Consequently, the temperature rises along the shower produced by the UHE neutrino. The refractive index of the medium rises with temperature. The irregularity of the refractive index in the medium leads to a reflection of radio waves. This reflection effect combined with the long attenuation length of radio waves in rock salt and ice would yield a new method to detect UHE neutrinos. We measured the phase of the reflected radio wave under irradiation with an electron beam on ice and rock salt powder. The measured phase showed excellent consis...

  10. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

    Science.gov (United States)

    Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Anzalone, A.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bäcker, T.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filipčič, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gonçalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Góra, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Hrabovský, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lautridou, P.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Aüera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mićanović, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafá, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Nhung, P. T.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parsons, R. D.; Pastor, S.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Phan, N.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Robledo, C.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schöder, F.; Schulte, S.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Stapleton, J.; Stasielak, J.; Stephan, M.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tamashiro, A.; Tapia, A.; Tartare, M.; Taşcąu, O.; Tavera Ruiz, C. G.; Tcaciuc, R.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tiwari, D. K.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Varela, E.; Vargas Cáardenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Winders, L.; Winnick, M. G.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.

    2011-06-01

    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 × 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

  11. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

    CERN Document Server

    Abreu, P; Ahn, E J; Albuquerque, I F M; Allard, D; Allekotte, I; Allen, J; Allison, P; Castillo, J Alvarez; Alvarez-Muñiz, J; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Antičić, T; Anzalone, A; Aramo, C; Arganda, E; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avenier, M; Avila, G; Bäcker, T; Balzer, M; Barber, K B; Barbosa, A F; Bardenet, R; Barroso, S L C; Baughman, B; Bäuml, J; Beatty, J J; Becker, B R; Becker, K H; Bellétoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blümer, H; Boháčová, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brogueira, P; Brown, W C; Bruijn, R; Buchholz, P; Bueno, A; Burton, R E; Caballero-Mora, K S; Caramete, L; Caruso, R; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Cheng, S H; Chiavassa, A; Chinellato, J A; Chou, A; Chudoba, J; Clay, R W; Coluccia, M R; Conceição, R; Contreras, F; Cook, H; Cooper, M J; Coppens, J; Cordier, A; Cotti, U; Coutu, S; Covault, C E; Creusot, A; Criss, A; Cronin, J; Curutiu, A; Dagoret-Campagne, S; Dallier, R; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; De Domenico, M; De Donato, C; de Jong, S J; De La Vega, G; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; de Vries, K D; Decerprit, G; del Peral, L; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Diaz, J C; Castro, M L Díaz; Diep, P N; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dong, P N; Dorofeev, A; Anjos, J C dos; Dova, M T; D'Urso, D; Dutan, I; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Etchegoyen, A; Luis, P Facal San; Tapia, I Fajardo; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Ferrero, A; Fick, B; Filevich, A; Filipčič, A; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Fröhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; García, B; Gámez, D García; Garcia-Pinto, D; Gascon, A; Gemmeke, H; Gesterling, K; Ghia, P L; Giaccari, U; Giller, M; Glass, H; Gold, M S; Golup, G; Albarracin, F Gomez; Berisso, M Gómez; Gonçalves, P; Gonzalez, D; Gonzalez, J G; Gookin, B; Góra, D; Gorgi, A; Gouffon, P; Gozzini, S R; Grashorn, E; Grebe, S; Griffith, N; Grigat, M; Grillo, A F; Guardincerri, Y; Guarino, F; Guedes, G P; Guzman, A; Hague, J D; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hojvat, C; Hollon, N; Holmes, V C; Homola, P; Hörandel, J R; Horneffer, A; Hrabovský, M; Huege, T; Insolia, A; Ionita, F; Italiano, A; Jarne, C; Jiraskova, S; Kadija, K; Kampert, K H; Karhan, P; Kasper, P; Kégl, B; Keilhauer, B; Keivani, A; Kelley, J L; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapp, J; Koang, D -H; Kotera, K; Krohm, N; Krömer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; Lautridou, P; Leão, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; López, K Link R; Agüera, A Lopez; Louedec, K; Bahilo, J Lozano; Lucero, A; Ludwig, M; Lyberis, H; Maccarone, M C; Macolino, C; Maldera, S; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, J; Marin, V; Maris, I C; Falcon, H R Marquez; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martínez; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Mertsch, P; Meurer, C; Mićanović, S; Micheletti, M I; Miller, W; Miramonti, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Morris, C; Mostafá, M; Moura, C A; Mueller, S; Muller, M A; Müller, G; Münchmeyer, M; Mussa, R; Navarra, G; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nelles, A; Nhung, P T; Niemietz, L; Nierstenhoefer, N; Nitz, D; Nosek, D; Nožka, L; Nyklicek, M; Oehlschläger, J; Olinto, A; Oliva, P; Olmos-Gilbaja, V M; Ortiz, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parra, A; Parsons, R D; Pastor, S; Paul, T; Pech, M; Pȩkala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrinca, P; Petrolini, A; Petrov, Y; Petrovic, J; Pfendner, C; Phan, N; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Ponce, V H; Pontz, M; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Rautenberg, J; Ravel, O; Ravignani, D; Revenu, B; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rivera, H; Rizi, V; Roberts, J; Robledo, C; de Carvalho, W Rodrigues; Rodriguez, G; Martino, J Rodriguez; Rojo, J Rodriguez; Rodriguez-Cabo, I; Rodríguez-Frías, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Rühle, C; Salamida, F; Salazar, H; Salina, G; Sánchez, F; Santander, M; Santo, C E; Santos, E; Santos, E M; Sarazin, F; Sarkar, B; Sarkar, S; Sato, R; Scharf, N; Scherini, V; Schieler, H; Schiffer, P; Schmidt, A; Schmidt, F; Schmidt, T; Scholten, O; Schoorlemmer, H; Schovancova, J; Schovánek, P; Schröder, F; Schulte, S; Schuster, D; Sciutto, S J; Scuderi, M; Segreto, A; Settimo, M; Shadkam, A; Shellard, R C; Sidelnik, I; Sigl, G; Lopez, H H Silva; Śmiałkowski, A; Šmída, R; Snow, G R; Sommers, P; Sorokin, J; Spinka, H; Squartini, R; Stapleton, J; Stasielak, J; Stephan, M; Strazzeri, E; Stutz, A; Suarez, F; Suomijärvi, T; Supanitsky, A D; Šuša, T; Sutherland, M S; Swain, J; Szadkowski, Z; Szuba, M; Tamashiro, A; Tapia, A; Tartare, M; Taşcău, O; Ruiz, C G Tavera; Tcaciuc, R; Tegolo, D; Thao, N T; Thomas, D; Tiffenberg, J; Timmermans, C; Tiwari, D K; Tkaczyk, W; Peixoto, C J Todero; Tomé, B; Tonachini, A; Travnicek, P; Tridapalli, D B; Tristram, G; Trovato, E; Tueros, M; Ulrich, R; Unger, M; Urban, M; Galicia, J F Valdés; Valiño, I; Valore, L; Berg, A M van den; Varela, E; Cárdenas, B Vargas; Vázquez, J R; Vázquez, R A; Veberič, D; Verzi, V; Vicha, J; Videla, M; Villaseñor, L; Wahlberg, H; Wahrlich, P; Wainberg, O; Warner, D; Watson, A A; Weber, M; Weidenhaupt, K; Weindl, A; Westerhoff, S; Whelan, B J; Wieczorek, G; Wiencke, L; Wilczyńska, B; Wilczyński, H; Will, M; Williams, C; Winchen, T; Winders, L; Winnick, M G; Wommer, M; Wundheiler, B; Yamamoto, T; Yapici, T; Younk, P; Yuan, G; Yushkov, A; Zamorano, B; Zas, E; Zavrtanik, D; Zavrtanik, M; Zaw, I; Zepeda, A; Ziolkowski, M

    2011-01-01

    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\\ 13,\\ 26$). If the anisotropies above $E_{th}$ are due to nuclei with charge $Z$, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

  12. Graphene-wrapped sulfur nanospheres with ultra-high sulfur loading for high energy density lithium-sulfur batteries

    Science.gov (United States)

    Liu, Ya; Guo, Jinxin; Zhang, Jun; Su, Qingmei; Du, Gaohui

    2015-01-01

    Lithium-sulfur (Li-S) battery with high theoretical energy density is one of the most promising energy storage systems for electric vehicles and intermittent renewable energy. However, due to the poor conductivity of the active material, considerable weight of the electrode is occupied by the conductive additives. Here we report a graphene-wrapped sulfur nanospheres composite (S-nanosphere@G) with sulfur content up to 91 wt% as the high energy density cathode material for Li-S battery. The sulfur nanospheres with diameter of 400-500 nm are synthesized through a solution-based approach with the existence of polyvinylpyrrolidone (PVP). Then the sulfur nanospheres are uniformly wrapped by conductive graphene sheets through the electrostatic interaction between graphene oxide and PVP, followed by reducing of graphene oxide with hydrazine. The design of graphene wrapped sulfur nanoarchitecture provides flexible conductive graphene coating with void space to accommodate the volume expansion of sulfur and to minimize polysulfide dissolution. As a result, the S-nanosphere@G nanocomposite with 91 wt% sulfur shows a reversible initial capacity of 970 mA h g-1 and an average columbic efficiency > 96% over 100 cycles at a rate of 0.2 C. Taking the total mass of electrode into account, the S-nanosphere@G composite is a promising cathode material for high energy density Li-S batteries.

  13. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

    NARCIS (Netherlands)

    Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, J. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castilo, J.; Alvarez-Muniz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anticic, T.; Anzalone, A.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, Ni.; Avila, G.; Baecker, T.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Baeuml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Belletoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Diaz, J. C.; Diaz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Luis, P. Facal San; Tapia, I. Fajardo; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filipcic, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Froehlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garcia, B.; Garcia Gamez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gomez Berisso, M.; Goncalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Gora, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hoerandel, J. R.; Horneffer, A.; Hrabovsky, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D. -H.; Kotera, K.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lautridou, P.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Agueera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martinez, H.; Martinez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Micanovic, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafa, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Mueller, G.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Nhung, P. T.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nozka, L.; Nyklicek, M.; Oehlschlaeger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parsons, R. D.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Phan, N.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Robledo, C.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Ruehle, C.; Salamida, F.; Salazar, H.; Salina, G.; Sanchez, F.; Santander, M.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovanek, P.; Schroeder, F.; Schulte, S.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Stapleton, J.; Stasielak, J.; Stephan, M.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijaervi, T.; Supanitsky, A. D.; Susa, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tamashiro, A.; Tapia, A.; Tartare, M.; Tascau, O.; Ruiz, C. G. Tavera; Tcaciuc, R.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tiwari, D. K.; Tkaczyk, W.; Todero Peixoto, C. J.; Tome, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van den Berg, A. M.; Varela, E.; Vargas Cardenas, B.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Winders, L.; Winnick, M. G.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.; Martin, L.

    2011-01-01

    The Pierre Auger Collaboration has reported. evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > E(th) = 5.5 x 10(19) eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the directi

  14. A Search for Correlation of Ultra-High Energy Cosmic Rays with IRAS-PSCz and 2MASS-6dF Galaxies

    CERN Document Server

    Oikonomou, Foteini; Abdalla, Filipe B; Lahav, Ofer; Thomas, Shaun A; Waters, David; Waxman, Eli

    2014-01-01

    We study the arrival directions of 69 ultra-high energy cosmic rays (UHECRs) observed at the Pierre Auger Observatory (PAO) with energies exceeding 55 EeV. We investigate whether the UHECRs exhibit the anisotropy signal expected if the primary particles are protons that originate in galaxies in the local universe, or in sources correlated with these galaxies. We cross-correlate the UHECR angular positions with the positions of IRAS-PSCz and 2MASS-6dF galaxies (with median depth of 120 and 225 Mpc respectively) weighted for GZK and other particle propagation effects. This is the first time that the 6dF survey is used for a study of this type and the first time that the PSCz survey is used with the full 69 publicly released PAO events. We find the probability that the observed UHECR events are consistent with an isotropic hypothesis to be less than 5% for most of the parameter space considered. The observed correlation is consistent with the mean of the model distribution of UHECRs associated with PSCz and 6dF ...

  15. Determination of the proton-to-helium ratio in cosmic rays at ultra-high energies from the tail of the $X_{\\rm max}$ distribution

    CERN Document Server

    Yushkov, Alexey; Werner, Marek; Krieg, Julius

    2016-01-01

    We present a method to determine the proton-to-helium ratio in cosmic rays at ultra-high energies. It makes use of the exponential slope, $\\Lambda$, of the tail of the $X_{\\rm max}$ distribution measured by an air shower experiment. The method is quite robust with respect to uncertainties from modeling hadronic interactions and to systematic errors on $X_{\\rm max}$ and energy, and to the possible presence of primary nuclei heavier than helium. Obtaining the proton-to-helium ratio with air shower experiments would be a remarkable achievement. To quantify the applicability of a particular mass-sensitive variable for mass composition analysis despite hadronic uncertainties we introduce as a metric the `analysis indicator' and find an improved performance of the $\\Lambda$ method compared to other variables currently used in the literature. The fraction of events in the tail of the $X_{\\rm max}$ distribution can provide additional information on the presence of nuclei heavier than helium in the primary beam.

  16. Graphene-wrapped sulfur nanospheres with ultra-high sulfur loading for high energy density lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ya; Guo, Jinxin; Zhang, Jun, E-mail: zhangjun@zjnu.cn; Su, Qingmei; Du, Gaohui, E-mail: gaohuidu@zjnu.edu.cn

    2015-01-01

    Graphical abstract: - Highlights: • A graphene-wrapped sulfur nanospheres composite with 91 wt% S is prepared. • It shows highly improved electrochemical performance as cathode for Li–S cell. • The PVP coating and conductive graphene minimize polysulfides dissolution. • The flexible coatings with void space accommodate the volume expansion of sulfur. - Abstract: Lithium–sulfur (Li–S) battery with high theoretical energy density is one of the most promising energy storage systems for electric vehicles and intermittent renewable energy. However, due to the poor conductivity of the active material, considerable weight of the electrode is occupied by the conductive additives. Here we report a graphene-wrapped sulfur nanospheres composite (S-nanosphere@G) with sulfur content up to 91 wt% as the high energy density cathode material for Li–S battery. The sulfur nanospheres with diameter of 400–500 nm are synthesized through a solution-based approach with the existence of polyvinylpyrrolidone (PVP). Then the sulfur nanospheres are uniformly wrapped by conductive graphene sheets through the electrostatic interaction between graphene oxide and PVP, followed by reducing of graphene oxide with hydrazine. The design of graphene wrapped sulfur nanoarchitecture provides flexible conductive graphene coating with void space to accommodate the volume expansion of sulfur and to minimize polysulfide dissolution. As a result, the S-nanosphere@G nanocomposite with 91 wt% sulfur shows a reversible initial capacity of 970 mA h g{sup −1} and an average columbic efficiency > 96% over 100 cycles at a rate of 0.2 C. Taking the total mass of electrode into account, the S-nanosphere@G composite is a promising cathode material for high energy density Li–S batteries.

  17. A search for ultra-high energy neutrinos in highly inclined events at the Pierre Auger Observatory

    CERN Document Server

    Abreu, P; Ahlers, M; Ahn, E J; Albuquerque, I F M; Allard, D; Allekotte, I; Allen, J; Allison, P; Almela, A; Castillo, J Alvarez; Alvarez-Muñiz, J; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Anticic, T; Aramo, C; Arganda, E; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avenier, M; Avila, G; Bäcker, T; Badescu, A M; Balzer, M; Barber, K B; Barbosa, A F; Bardenet, R; Barroso, S L C; Baughman, B; Bäuml, J; Beatty, J J; Becker, B R; Becker, K H; Bellétoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blümer, H; Bohácová, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brancus, I; Brogueira, P; Brown, W C; Bruijn, R; Buchholz, P; Bueno, A; Burton, R E; Caballero-Mora, K S; Caccianiga, B; Caramete, L; Caruso, R; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Cheng, S H; Chiavassa, A; Chinellato, J A; Diaz, J Chirinos; Chudoba, J; Clay, R W; Coluccia, M R; Concei\\ccão, R; Contreras, F; Cook, H; Cooper, M J; Coppens, J; Cordier, A; Coutu, S; Covault, C E; Creusot, A; Criss, A; Cronin, J; Curutiu, A; Dagoret-Campagne, S; Dallier, R; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; De Domenico, M; De Donato, C; de Jong, S J; De La Vega, G; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; de Vries, K D; del Peral, L; del R\\'\\io, M; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Castro, M L D\\'\\iaz; Diep, P N; Diogo, F; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dong, P N; Dorofeev, A; Anjos, J C dos; Dova, M T; D'Urso, D; Dutan, I; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Luis, P Facal San; Tapia, I Fajardo; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Fick, B; Filevich, A; Filipcic, A; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Fratu, O; Fröhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; García, B; Roca, S T Garcia; Garcia-Gamez, D; Garcia-Pinto, D; Gascon, A; Gemmeke, H; Ghia, P L; Giaccari, U; Giller, M; Glass, H; Gold, M S; Golup, G; Albarracin, F Gomez; Berisso, M Gómez; Vitale, P F Gómez; Gonçalves, P; Gonzalez, D; Gonzalez, J G; Gookin, B; Gorgi, A; Gouffon, P; Grashorn, E; Grebe, S; Griffith, N; Grigat, M; Grillo, A F; Guardincerri, Y; Guarino, F; Guedes, G P; Guzman, A; Hansen, P; Harari, D; Harmsma, S; Harrison, T A; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hojvat, C; Hollon, N; Holmes, V C; Homola, P; Hörandel, J R; Horneffer, A; Horvath, P; Hrabovský, M; Huber, D; Huege, T; Insolia, A; Ionita, F; Italiano, A; Jarne, C; Jiraskova, S; Josebachuili, M; Kadija, K; Kampert, K H; Karhan, P; Kasper, P; Kégl, B; Keilhauer, B; Keivani, A; Kelley, J L; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapp, J; Koang, D -H; Kotera, K; Krohm, N; Krömer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; Lauer, R; Lautridou, P; Coz, S Le; Leão, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; López, R; Agüera, A Lopez; Louedec, K; Bahilo, J Lozano; Lu, L; Lucero, A; Ludwig, M; Lyberis, H; Macolino, C; Maldera, S; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, J; Marin, V; Maris, I C; Falcon, H R Marquez; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martínez; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurel, D; Maurizio, D; Mazur, P O; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Mertsch, P; Meurer, C; Micanovic, S; Micheletti, M I; Miramonti, L; Molina-Bueno, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Mostafá, M; Moura, C A; Muller, M A; Müller, G; Münchmeyer, M; Mussa, R; Navarra, G; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Newton, D; Nhung, P T; Niechciol, M; Niemietz, L; Nierstenhoefer, N; Nitz, D; Nosek, D; Nožka, L; Nyklicek, M; Oehlschläger, J; Olinto, A; Ortiz, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parra, A; Pastor, S; Paul, T; Pech, M; Pekala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrinca, P; Petrolini, A; Petrov, Y; Pfendner, C; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Ponce, V H; Pontz, M; Porcelli, A; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Rautenberg, J; Ravel, O; Ravignani, D; Revenu, B; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rivera, H; Rizi, V; Roberts, J; de Carvalho, W Rodrigues; Rodriguez, G; Martino, J Rodriguez; Rojo, J Rodriguez; Rodriguez-Cabo, I; Rodríguez-Frías, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Rühle, C; Saftoiu, A; Salamida, F; Salazar, H; Greus, F Salesa; Salina, G; Sánchez, F; Santo, C E; Santos, E; Santos, E M; Sarazin, F; Sarkar, B; Sarkar, S; Sato, R; Scharf, N; Scherini, V; Schieler, H; Schiffer, P; Schmidt, A; Scholten, O; Schoorlemmer, H; Schovancova, J; Schovánek, P; Schröder, F; Schulte, S; Schuster, D; Sciutto, S J; Scuderi, M; Segreto, A; Settimo, M; Shadkam, A; Shellard, R C; Sidelnik, I; Sigl, G; Lopez, H H Silva; Sima, O; Smialkowski, A; Šmída, R; Snow, G R; Sommers, P; Sorokin, J; Spinka, H; Squartini, R; Srivastava, Y N; Stanic, S; Stapleton, J; Stasielak, J; Stephan, M; Stutz, A; Suarez, F; Suomijärvi, T; Supanitsky, A D; Šuša, T; Sutherland, M S; Swain, J; Szadkowski, Z; Szuba, M; Tapia, A; Tartare, M; Tascau, O; Ruiz, C G Tavera; Tcaciuc, R; Tegolo, D; Thao, N T; Thomas, D; Tiffenberg, J; Timmermans, C; Tkaczyk, W; Peixoto, C J Todero; Toma, G; Tomé, B; Tonachini, A; Travnicek, P; Tridapalli, D B; Tristram, G; Trovato, E; Tueros, M; Ulrich, R; Unger, M; Urban, M; Galicia, J F Valdés; Valiño, I; Valore, L; Berg, A M van den; Varela, E; Cárdenas, B Vargas; Vázquez, J R; Vázquez, R A; Veberic, D; Verzi, V; Vicha, J; Videla, M; Villaseñor, L; Wahlberg, H; Wahrlich, P; Wainberg, O; Walz, D; Watson, A A; Weber, M; Weidenhaupt, K; Weindl, A; Werner, F; Westerhoff, S; Whelan, B J; Widom, A; Wieczorek, G; Wiencke, L; Wilczynska, B; Wilczynski, H; Will, M; Williams, C; Winchen, T; Wommer, M; Wundheiler, B; Yamamoto, T; Yapici, T; Younk, P; Yuan, G; Yushkov, A; Zamorano, B; Zas, E; Zavrtanik, D; Zavrtanik, M; Zaw, I; Zepeda, A; Zhu, Y; Silva, M Zimbres; Ziolkowski, M

    2012-01-01

    The Surface Detector of the Pierre Auger Observatory is sensitive to neutrinos of all flavours above 0.1 EeV. These interact through charged and neutral currents in the atmosphere giving rise to extensive air showers. When interacting deeply in the atmosphere at nearly horizontal incidence, neutrinos can be distinguished from regular hadronic cosmic rays by the broad time structure of their shower signals in the water-Cherenkov detectors. In this paper we present for the first time an analysis based on down-going neutrinos. We describe the search procedure, the possible sources of background, the method to compute the exposure and the associated systematic uncertainties. No candidate neutrinos have been found in data collected from 1 January 2004 to 31 May 2010. Assuming an E^-2 differential energy spectrum the limit on the single flavour neutrino is (E^2 * dN/dE) < 1.74x10^-7 GeV cm^-2 s^-1 sr^-1 at 90% C.L. in the energy range 1x10^17 eV < E < 1x10^20 eV.

  18. Analysis of large-scale anisotropy of ultra-high energy cosmic rays in HiRes data

    CERN Document Server

    Abbasi, R U; Allen, M; Amann, J F; Archbold, G; Belov, K; Belz, J W; Bergman, D R; Blake, S A; Brusova, O A; Burt, G W; Cannon, C; Cao, Z; Deng, W; Fedorova, Y; Findlay, J; Finley, C B; Gray, R C; Hanlon, W F; Hoffman, C M; Holzscheiter, M H; Hughes, G; Hüntemeyer, P; Ivanov, D; Jones, B F; Jui, C C H; Kim, K; Kirn, M A; Koers, H; Loh, E C; Maestas, M M; Manago, N; Marek, L J; Martens, K; Matthews, J A J; Matthews, J N; Moore, S A; O'Neill, A; Painter, C A; Perera, L; Reil, K; Riehle, R; Roberts, M D; Rodriguez, D; Sasaki, M; Schnetzer, S R; Scott, L M; Sinnis, G; Smith, J D; Sokolsky, P; Song, C; Springer, R W; Stokes, B T; Stratton, S R; Thomas, J R; Thomas, S B; Thomson, G B; Tinyakov, P; Tupa, D; Wiencke, L R; Zech, A; Zhang, X

    2010-01-01

    Stereo data collected by the HiRes experiment over a six year period are examined for large-scale anisotropy related to the inhomogeneous distribution of matter in the nearby Universe. We consider the generic case of small cosmic-ray deflections and a large number of sources tracing the matter distribution. In this matter tracer model the expected cosmic ray flux depends essentially on a single free parameter, the typical deflection angle theta. We find that the HiRes data with threshold energies of 40 EeV and 57 EeV are incompatible with the matter tracer model at a 95% confidence level unless theta is larger than 10 degrees and are compatible with an isotropic flux. The data set above 10 EeV is compatible with both the matter tracer model and an isotropic flux.

  19. Ultra-high energy collisions in static space-times: single versus multi-black hole cases

    CERN Document Server

    Zaslavskii, O B

    2014-01-01

    We consider collision of two particles near static electrically charged extremal black holes and elucidate the conditions under which the energy in the centre of mass frame E_{c.m.} grows unbounded. For a single black hole, we generalize the results obtained earlier for the Reissner-Nordstr\\"om metric, to distorted black holes. In the multi-black hole space-time, qualitatively new features appear. If the point of collision is close to at least two horizons simultaneously, unbounded E_{c.m.} are possible (i) without fine-tuning of particles' parameters, (ii) for an arbitrary mutual orientation of two velocities. Such a combination of properties (i) and (ii) has no analogues in the single black hole case and facilitates the condition of getting unbounded E_{c.m.}. Collisions in the electro-vacuum Majumdar-Papapetrou metric (several extremal black holes in equilibrium) is analyzed explicitly.

  20. A METHOD TO SEARCH FOR CORRELATIONS OF ULTRA-HIGH ENERGY COSMIC-RAY MASSES WITH THE LARGE-SCALE STRUCTURES IN THE LOCAL GALAXY DENSITY FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A. A., E-mail: ivanov@ikfia.ysn.ru [Shafer Institute for Cosmophysical Research and Aeronomy, 31 Lenin Avenue, Yakutsk 677980 (Russian Federation)

    2013-02-15

    One of the main goals of investigations using present and future giant extensive air shower (EAS) arrays is the mass composition of ultra-high energy cosmic rays (UHECRs). A new approach to the problem is presented, combining the analysis of arrival directions with the statistical test of the paired EAS samples. One of the ideas of the method is to search for possible correlations between UHECR masses and their separate sources; for instance, if there are two sources in different areas of the celestial sphere injecting different nuclei, but the fluxes are comparable so that arrival directions are isotropic, then the aim is to reveal a difference in the mass composition of cosmic-ray fluxes. The method is based on a non-parametric statistical test-the Wilcoxon signed-rank routine-which does not depend on the populations fitting any parameterized distributions. Two particular algorithms are proposed: first, using measurements of the depth of the EAS maximum position in the atmosphere; and second, relying on the age variance of air showers initiated by different primary particles. The formulated method is applied to the Yakutsk array data, in order to demonstrate the possibility of searching for a difference in average mass composition between the two UHECR sets, arriving particularly from the supergalactic plane and a complementary region.

  1. Detection of the ultra-high z short GRB 080913 and its implications on progenitors and energy extraction mechanisms

    CERN Document Server

    Pérez-Ramírez, D; Gorosabel, J; Aloy, M A; Guerrero, M A; Osborne, J P; Page, K L; Warwick, R S; Horváth, I; Veres, P; Jelinek, M; Kubánek, P; Guziy, S; Bremer, M; Winters, J M; Castro-Tirado, A J

    2008-01-01

    Aims: We present multiwavelength observations of the most distant gamma-ray burst detected so far GRB 080913 and study whether it can be considered a short-duration GRB and the implications for the progenitor nature and energy extraction mechanisms. Methods: Multiwavelength (X-ray/nIR/millimetre) observations were made between 20.7 hours and ~16.8 days after the event. Results: Whereas a very faint afterglow was seen at the 3.5m CAHA telescope in the nIR, the X-ray afterglow was clearly detected in our XMM-Newton observations. An upper limit is reported in the mm range. At typical redshifts of other bursts, GRB 080913 would be found in the locus of short-duration GRBs on a hardness-duration diagram, thus strengthening its membership of this class. We also report that GRB 080913 shows lower isotropic luminosities than GRB 060121, another likely member of the short-duration class of GRB at z~4.6. Regarding the nature of the progenitor, we find that a NS+BH is slightly preferred over a double NS merger, with the...

  2. A search for correlation of ultra-high energy cosmic rays with IRAS-PSCz and 2MASS-6dF galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Oikonomou, Foteini; Abdalla, Filipe B.; Lahav, Ofer; Thomas, Shaun A. [Astrophysics Group, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Connolly, Amy [Department of Physics and CCAPP, The Ohio State University, 191 West Woodruff Avenue, Colombus, Ohio 43210 (United States); Waters, David [High Energy Physics Group, Department of Physics and Astronomy, University College London (United Kingdom); Waxman, Eli, E-mail: fotini@star.ucl.ac.uk, E-mail: connolly@physics.osu.edu, E-mail: fba@star.ucl.ac.uk, E-mail: o.lahav@ucl.ac.uk, E-mail: sat@star.ucl.ac.uk, E-mail: d.waters@ucl.ac.uk, E-mail: eli.waxman@weizmann.ac.il [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2013-05-01

    We study the arrival directions of 69 ultra-high energy cosmic rays (UHECRs) observed at the Pierre Auger Observatory (PAO) with energies exceeding 55 EeV. We investigate whether the UHECRs exhibit the anisotropy signal expected if the primary particles are protons that originate in galaxies in the local universe, or in sources correlated with these galaxies. We cross-correlate the UHECR arrival directions with the positions of IRAS-PSCz and 2MASS-6dF galaxies taking into account particle energy losses during propagation. This is the first time that the 6dF survey is used in a search for the sources of UHECRs and the first time that the PSCz survey is used with the full 69 PAO events. The observed cross-correlation signal is larger for the PAO UHECRs than for 94% (98%) of realisations from an isotropic distribution when cross-correlated with the PSCz (6dF). On the other hand the observed cross-correlation signal is lower than that expected from ∼>85% of realisations, had the UHECRs originated in galaxies in either survey. The observed cross-correlation signal does exceed that expected by 50% of the realisations if the UHECRs are randomly deflected by intervening magnetic fields by 5° or more. We propose a new method of analysing the expected anisotropy signal, by dividing the predicted UHECR source distribution into equal predicted flux radial shells, which can help localise and constrain the properties of UHECR sources. We find that the 69 PAO events are consistent with isotropy in the nearest of three shells we define, whereas there is weak evidence for correlation with the predicted source distribution in the two more distant shells in which the galaxy distribution is less anisotropic.

  3. Comment on "The Lamb Shift and Ultra High Energy Cosmic Rays" and Comment on "Vacuum Polarization Energy Losses of High Energy Cosmic Rays"

    CERN Document Server

    Deligny, O

    2002-01-01

    The cosmic rays spectrum has been shown to extend well beyond 10^20 eV. With nearly 20 events observed in the last 40 years, it is now established that particles with energies near or above 10^21 eV. No nearby astrophysical object has been shown to correlate with the arrival directions of the highest energy events, yet the exponential cut-off in the high energy end of the spectrum one expects to see in the case of far sources is not visible. It was recently pointed out that the influence of the vacuum of quantum electrodynamics on particle propagation could explain qualitatively this mystery. This note is a critic to these ideas.

  4. Development and data analysis of a radio-detection of ultra high energy cosmic rays experiment; Developpement et analyse des donnees d'une experience de radiodetection des rayons cosmiques d'ultra haute energie

    Energy Technology Data Exchange (ETDEWEB)

    Belletoile, A

    2007-10-15

    The radio-detection of cosmic rays was first attempted in the sixties. Unfortunately at that time, the results suffered from poor reproducibility and the technique was abandoned in favour of direct particle and fluorescence detection. Taking advantage of recent technological improvements the radio-detection of ultra high energy cosmic rays is being reinvestigated. In this document, first, we remind the reader of the global problematic of cosmic rays. Then, the several mechanisms involved in the emission of an electric field associated with extensive air showers are discussed. The CODALEMA (cosmic detection array with logarithmic electro magnetic antenna) experiment that aims to demonstrate the feasibility of cosmic ray radio-detection, is extensively described along with the first experimental results. A radio-detection test experiment implanted at the giant detector Pierre Auger is presented. It should provide inputs to design the future detector using this technique at extreme energies. (author)

  5. Ultra-High Temperature Gratings

    Institute of Scientific and Technical Information of China (English)

    John Canning; Somnath Bandyopadhyay; Michael Stevenson; Kevin Cook

    2008-01-01

    Regenerated gratings seeded by type-Ⅰ gratings are shown to withstand temperatures beyond 1000 ℃. The method of regeneration offers a new approach to increasing temperature resistance of stable fibre Bragg and other gratings. These ultra-high temperature (UHT) gratings extend the applicability of silicate based components to high temperature applications such as monitoring of smelters and vehicle and aircraft engines to high power fibre lasers.

  6. Radiation Pressure Acceleration: the factors limiting maximum attainable ion energy

    CERN Document Server

    Bulanov, S S; Schroeder, C B; Bulanov, S V; Esirkepov, T Zh; Kando, M; Pegoraro, F; Leemans, W P

    2016-01-01

    Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it trans...

  7. An investigation of mass composition of ultra-high energy cosmic rays with energies above 1019 eV via the study of extensive air showers

    Directory of Open Access Journals (Sweden)

    Doostmohammadi S.

    2012-01-01

    Full Text Available The electron and muon components of extensive air shower (EAS with energies above 1019 eV are analyzed via various giant EAS arrays. A varying property of showers is observed for two energy ranges; higher and lower than (3 − 4 x 1019 eV. The age parameter, zenith angle, shower size dependence on muon size and shower size dependence on primary energy show an increment of mass composition (MC above (3−4x 1019eV. Comparison of the observed EAS results with the simulations of Capdevielle et al. (2000 and Shinozaki et al. (2005 gives at most 20% photon fraction for primary energies above 1019 eV. The arrival directions of showers above 4x1019 eV indicate an increasing concentration towards the super galactic plane.

  8. Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation.

    Science.gov (United States)

    Schroeder, J L; Thomson, W; Howard, B; Schell, N; Näslund, L-Å; Rogström, L; Johansson-Jõesaar, M P; Ghafoor, N; Odén, M; Nothnagel, E; Shepard, A; Greer, J; Birch, J

    2015-09-01

    We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (>50 keV), high photon flux (>10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (<1 s) two-dimensional (2D) detector, permits time-resolved in situ structural analysis of thin film formation processes. The high-energy synchrotron-radiation based x-rays result in small scattering angles (<11°), allowing large areas of reciprocal space to be imaged with a 2D detector. The system has been designed for use on the 1-tonne, ultra-high load, high-resolution hexapod at the P07 High Energy Materials Science beamline at PETRA III at the Deutsches Elektronen-Synchrotron in Hamburg, Germany. The deposition system includes standard features of a typical UHV deposition system plus a range of special features suited for synchrotron radiation studies and industry-relevant processes. We openly encourage the materials research community to contact us for collaborative opportunities using this unique and versatile scientific instrument.

  9. Underwater acoustic detection of ultra high energy neutrinos in Antares; Detection acoustique sous-marine de neutrinos de ultra haute energie dans le cadre de l'experience ANTARES

    Energy Technology Data Exchange (ETDEWEB)

    Niess, V

    2005-09-15

    We investigate the possibility to detect ultra high energy neutrinos (UHE, 1018+ eV) by the mean of underwater acoustic methods. This study is based on experimental measurements and, when none of those are available, on numerical simulations. The sea water acts as a target for neutrinos of cosmic origin. The electroweak interaction of high energy neutrinos with water molecules leads to a cascade of secondary particles resulting in the emission of an ultra-sonic impulse by a thermo-acoustic coupling mechanism. This mechanism is little efficient, however the generated signal has good propagation properties. Ambient sea noise, as well as the self noise of the ceramic transducers used for the detection, restrict the method to UHE. In addition, the strong directivity of the signal implies that location methods, by the detection in coincidence on multiple detectors, are little efficient. At extremely high energies (10{sup 20}+ eV) and for a single detector we estimate the sensitivity limit of this acoustic method to be of the order of E{sup 2}*{phi} 10{sup 6} GeV cm{sup -2} sr{sup -1}*s{sup -1}, for an astrophysical flux 0 falling as 1/E{sup 2}. (author)

  10. UH-FLUX: Compact, Energy Efficient Superconducting Asymmetric Energy Recovery LINAC for Ultra-high Fluxes of X-ray and THz Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Konoplev, Ivan [Univ. of Oxford (United Kingdom). JAI, Dept. of Physics; Ainsworth, Robert [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Burt, Graeme [Lancaster Univ. (United Kingdom). Cockcroft Inst.; Seryi, Andrei [Univ. of Oxford (United Kingdom). JAI, Dept. of Physics

    2016-06-01

    The conventional ERLs have limited peak beam current because increasing the beam charge and repetition rate leads to appearance of the beam break-up instabilities. At this stage the highest current, from the SRF ERL, is around 300 mA. A single-turn (the beam will be transported through the accelerating section, interaction point and deceleration section of the AERL only once) Asymmetric Energy Recovery LINAC (AERL) is proposed. The RF cells in different sections of the cavity are tuned in such a way that only operating mode is uniform inside all of the cells. The AERL will drive the electron beams with typical energies of 10 - 30 MeV and peak currents above 1 A, enabling the generation of high flux UV/X-rays and high power coherent THz radiation. We aim to build a copper prototype of the RF cavity for a compact AERL to study its EM properties. The final goal is to build AERL based on the superconducting RF cavity. Preliminary design for AERL's cavity has been developed and will be presented. The results of numerical and analytical models and the next steps toward the AERL operation will also be discussed.

  11. UH-FLUX: Compact, Energy Efficient Superconducting Asymmetric Energy Recovery LINAC for Ultra-high Fluxes of X-ray and THz Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Konoplev, Ivan [JAI, UK; Ainsworth, Robert [Fermilab; Burt, Graeme [Lancaster U.; Seryi, Andrei [JAI, UK

    2016-06-01

    The conventional ERLs have limited peak beam current because increasing the beam charge and repetition rate leads to appearance of the beam break-up instabilities. At this stage the highest current, from the SRF ERL, is around 300 mA. A single turn (the beam will be transported through the accelerating section, interaction point and deceleration section of the AERL only once) Asymmetric Energy Recovery LINAC (AERL) is proposed. The RF cells in different sections of the cavity are tuned in such a way that only operating mode is uniform inside all of the cells. The AERL will drive the electron beams with typical energies of 10 - 30 MeV and peak currents above 1 A, enabling the generation of high flux UV/X-rays and high power coherent THz radiation. We aim to build a copper prototype of the RF cavity for a compact AERL to study its EM properties. The final goal is to build AERL based on the superconducting RF cavity. Preliminary design for AERL's cavity has been developed and will be presented. The results of numerical and analytical models and the next steps toward the AERL operation will also be discussed.

  12. Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Seletskiy, Sergei M. [Univ. of Rochester, NY (United States)

    2005-01-01

    Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the ¯rst cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cool- ing. The Recycler Electron Cooler (REC) is the key component of the Teva- tron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV car- rying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 ¹rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible.

  13. Influence of the atmosphere on the space detection of ultra-high energy cosmic rays; Influence de l'atmosphere sur la detection spatiale des rayons cosmiques d'ultra-haute energie

    Energy Technology Data Exchange (ETDEWEB)

    Moreggia, S

    2007-06-15

    EUSO (Extreme Universe Space Observatory) is a project of ultra-high energy (> 10{sup 20} eV) cosmic rays detection from space. Its concept relies on the observation of fluorescence and Cerenkov photons emitted by extensive air showers from a telescope located on the International Space Station. A simulation software has been developed to study the characteristics of this innovative concept of detection. It deals with the different steps of the detection chain: extensive air shower development, emission of fluorescence and Cerenkov light, and radiative transfer to the telescope. A Monte-Carlo code has been implemented to simulate the propagation of photons through the atmosphere, dealing with multiple scattering in clear sky conditions as well as in presence of aerosols and clouds. With this simulation program, the impact of atmospheric conditions on the performance of a space-located detector has been studied. The precise treatment of photons propagation through the atmosphere has permitted to quantify the scattered light contribution to the detected signal. (author)

  14. Ultra-high resolution computed tomography imaging

    Energy Technology Data Exchange (ETDEWEB)

    Paulus, Michael J. (Knoxville, TN); Sari-Sarraf, Hamed (Knoxville, TN); Tobin, Jr., Kenneth William (Harriman, TN); Gleason, Shaun S. (Knoxville, TN); Thomas, Jr., Clarence E. (Knoxville, TN)

    2002-01-01

    A method for ultra-high resolution computed tomography imaging, comprising the steps of: focusing a high energy particle beam, for example x-rays or gamma-rays, onto a target object; acquiring a 2-dimensional projection data set representative of the target object; generating a corrected projection data set by applying a deconvolution algorithm, having an experimentally determined a transfer function, to the 2-dimensional data set; storing the corrected projection data set; incrementally rotating the target object through an angle of approximately 180.degree., and after each the incremental rotation, repeating the radiating, acquiring, generating and storing steps; and, after the rotating step, applying a cone-beam algorithm, for example a modified tomographic reconstruction algorithm, to the corrected projection data sets to generate a 3-dimensional image. The size of the spot focus of the beam is reduced to not greater than approximately 1 micron, and even to not greater than approximately 0.5 microns.

  15. Propagation and sky distribution of ultra-high energy cosmic rays; Propagation et distribution sur le ciel des rayons cosmiques d'ultra-haute energie dans le cadre de l'Observatoire Pierre Auger

    Energy Technology Data Exchange (ETDEWEB)

    Armengaud, E

    2006-05-15

    The origin of ultra-high energy cosmic rays remains an enigma of modern physics, which the Pierre Auger Observatory, a detector with a hybrid detection mode and an unprecedented size, will try to solve. The direct observation of the sources of those particles, or of large-scale structures in the sky associated to the sources, is one of the main goals of the observatory. Such observations should also allow to constrain cosmic ray propagation between their sources and the Earth, which is complicated by interactions with low-energy photon backgrounds and deflections in astrophysical magnetic fields. This thesis is made of two parts, in order to observe and simulate the sources of cosmic rays within the Auger Observatory. We begin with an extensive description of the Pierre Auger Observatory, and study the acceptance of its surface detector in order to build accurate sky exposure maps, an essential tool in order to study anisotropies. Then we present methods to search for anisotropies in the sky, and analyze the first two years of Auger data. After a description of the phenomena that can influence the propagation and observation of ultrahigh energy cosmic ray sources, we present numerical simulations aiming at predicting observables such as the spectrum, anisotropies and composition measurable by Auger as a function of various astrophysical models. We show that extragalactic magnetic fields can play a crucial role in particular if cosmic rays are partly heavy nuclei. Finally, we show that the propagation of these particles from a nearby source generates secondary fluxes of gamma-rays that could be detected by TeV gamma-ray telescopes. (author)

  16. ULTRA HIGH POWER TRANSMISSION LINE TECHNIQUES

    Science.gov (United States)

    The ultra-high power transmission line techniques including both failure mechanisms and component design are discussed. Failures resulting from...a waveguide. In view of the many advantages of the low loss mode in circular waveguide for ultra-high power levels, a mode transducer and a two...percent of the peak power of a standard rectangular wave guide. Water cooling is provided for high average power operation. Analysis of mode sup pression

  17. Large Scale Distribution of Ultra High Energy Cosmic Rays Detected at the Pierre Auger Observatory with Zenith Angles up to 80°

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D’Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Freire, M. M.; Fröhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; García, B.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Müller, S.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.

    2015-01-01

    We present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60° and 80°. We perform two Rayleigh analyses, one in

  18. Large scale anisotropy studies of ultra high energy cosmic rays using data taken with the surface detector of the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Grigat, Marius

    2011-06-10

    The distribution of arrival directions of cosmic rays is remarkably uniform over the complete spectrum of energies. At large angular scales only tiny deviations from isotropy have been observed and huge statistics are required to quantify the corresponding amplitudes. The measurement of cosmic rays with energies above 10{sup 15} eV is only feasible with large, earthbound observatories: The cosmic ray primary particles initiate cascades of secondary particles in the Earth's atmosphere. Every aspect of the development of these air showers down to the measurement of the resulting particles at ground level needs to be well understood and controlled in order to precisely reconstruct the properties of the primary particle. The development of air showers is subject to systematic distortions caused by the magnetic field of the Earth. Both this and other local effects are capable of inducing false anisotropy into the distribution of arrival directions. In this thesis, the effect of the geomagnetic field on the energy measurement is modelled and quantified; consequently, a correction of the energy estimator is derived. Furthermore, a method is introduced to fit dipolar patterns to the distribution of arrival directions of cosmic rays as observed from the field of view of the surface detector of the Pierre Auger Observatory. After correcting for all relevant local effects the method is applied to data and the parameters of a potentially underlying dipole are determined and evaluated. (orig.)

  19. LARGE SCALE DISTRIBUTION OF ULTRA HIGH ENERGY COSMIC RAYS DETECTED AT THE PIERRE AUGER OBSERVATORY WITH ZENITH ANGLES UP TO 80 degrees

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Batista, R. Alves; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Diaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Hasankiadeh, Q. Dorosti; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Fox, B. D.; Fratu, O.; Freire, M. M.; Froehlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; Garcia, B.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Berisso, M.; Gomez Vitale, P. F.; Goncalves, P.; Gonzalez, J. G.; Gonzalez, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Horandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kaeaepae, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Masias Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Micanovic, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morello, C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Mueller, G.; Mueller, S.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nozka, L.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Fernandez, G. Rodriguez; Rodriguez Rojo, J.; Rodriguez-Frias, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Greus, F. Salesa; Salina, G.; Sanchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovanek, P.; Schroeder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijaervi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Ulrich, R.; Unger, M.; Urban, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.

    2015-01-01

    We present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60 degrees and 80 degrees. We perform two Rayleigh ana

  20. SEARCH FOR POINT-LIKE SOURCES OF ULTRA-HIGH ENERGY NEUTRINOS AT THE PIERRE AUGER OBSERVATORY AND IMPROVED LIMIT ON THE DIFFUSE FLUX OF TAU NEUTRINOS

    NARCIS (Netherlands)

    Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antici'c, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Belletoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De la Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; del Rio, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Diaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Froehlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garcia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gomez Berisso, M.; Gomez Vitale, P. F.; Goncalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hoerandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D. -H.; Kotera, K.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; LaHurd, D.; Latronico, L.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Agueera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Falcon, H. R. Marquez; Marsella, G.; Martello, D.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Meza, J. J. Masias; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Meyhandan, R.; Mi'canovi'c, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Mueller, G.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nozka, L.; Oehlschlaeger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.

    2012-01-01

    The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E-nu between 10(17) eV and 10(20) eV from point-like sources across the sky south of +55 degrees and north of -65 degrees declinations. A search has been performed for highly inclined extensive air showers pr

  1. Asymmetric Dual Axis Energy Recovery Linac for Ultra-High Flux sources of coherent X-ray/THz radiation: Investigations Towards its Ultimate Performance

    CERN Document Server

    Ainsworth, R; Konoplev, I V; Seryi, A

    2015-01-01

    Truly compact and high current, efficient particle accelerators are required for sources of coherent high brightness and intensity THz and X-Ray radiation to be accepted by university or industrial R&D laboratories. The demand for compactness and efficiency can be satisfied by superconducting RF energy recovery linear accelerators (SRF ERL) allowing effectively minimising the footprint and maximising the efficiency of the system. However such set-ups are affected by regenerative beam-break up (BBU) instabilities which limit the beam current and may terminate the beam transport as well as energy recuperation. In this paper we suggest and discuss a SRF ERL with asymmetric configuration of accelerating and decelerating cavities resonantly coupled. In this model of SRF ERL we propose an electron bunch passing through accelerating and decelerating cavities each once and we show that in this case the regenerative BBU instability can be minimised allowing high currents to be achieved. We study the BBU start curr...

  2. High energy-resolution x-ray spectroscopy at ultra-high dilution with spherically bent crystal analyzers of 0.5 m radius

    CERN Document Server

    Rovezzi, Mauro; Manceau, Alain; Glatzel, Pieter; Verbeni, Roberto

    2016-01-01

    We present the development, manufacturing and performance of spherically bent crystal analyzers (SBCAs) of 100 mm diameter and 0.5 m bending radius. The elastic strain in the crystal wafer is partially released by a "strip-bent" method where the crystal wafer is cut in strips prior to the anodic bonding process. Compared to standard 1 m SBCAs, a gain in intensity is obtained without loss of energy resolution. The gain ranges between 2.5 and 7, depending on the experimental conditions and the width of the emission line measured. This reduces the acquisition times required to perform high energy-resolution x-ray absorption and emission spectroscopy on ultra-dilute species, accessing concentrations of the element of interest down to, or below, the ppm (ng/mg) level.

  3. Simultaneous determination of taurine, glucuronolactone and glucuronic acid in energy drinks by ultra high performance liquid chromatography-tandem mass spectrometry (triple quadrupole).

    Science.gov (United States)

    Ricciutelli, Massimo; Caprioli, Giovanni; Cortese, Manuela; Lombardozzi, Antonietta; Strano, Morela; Vittori, Sauro; Sagratini, Gianni

    2014-10-17

    In this work, we present for the first time a rapid and robust UHPLC-MS/MS method for analyzing taurine, GlcLA and GlcA in energy drinks simultaneously and without derivatization. The separation of three analytes was achieved using a Kinetex Hilic analytical column (100 mm × 4.6 mm i.d.) and a mobile phase formed by water (A) and acetonitrile (B) both with formic acid 0.1% at a flow rate of 0.8 ml min(-1) with isocratic elution in 3.5 min. Calibration curves were calculated using the method of standard addition in a concentration range from 2 to 6 mg/100 ml for taurine (R(2)>0.987), from 0.4 to 1.2 mg/100 ml for GlcLa (R(2)>0.997), and from 0.2 to 0.6 mg/100 ml for GlcA acid (R(2)>0.998). The validated method was applied to the analysis of nine commercial energy drinks. The level of taurine found ranged from 0.01 to 0.45 g/100 ml, and it matched with that reported in the labels of the analyzed energy drink samples.

  4. SEARCH FOR POINT-LIKE SOURCES OF ULTRA-HIGH ENERGY NEUTRINOS AT THE PIERRE AUGER OBSERVATORY AND IMPROVED LIMIT ON THE DIFFUSE FLUX OF TAU NEUTRINOS

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, P.; Andringa, S. [LIP and Instituto Superior Tecnico, Technical University of Lisbon (Portugal); Aglietta, M. [Istituto di Fisica dello Spazio Interplanetario (INAF), Universita di Torino and Sezione INFN, Torino (Italy); Ahlers, M. [University of Wisconsin, Madison, WI (United States); Ahn, E. J. [Fermilab, Batavia, IL (United States); Albuquerque, I. F. M. [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo, SP (Brazil); Allard, D. [Laboratoire AstroParticule et Cosmologie (APC), Universite Paris 7, CNRS-IN2P3, Paris (France); Allekotte, I. [Centro Atomico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina); Allen, J. [New York University, New York, NY (United States); Allison, P. [Ohio State University, Columbus, OH (United States); Almela, A. [Universidad Tecnologica Nacional - Facultad Regional Buenos Aires, Buenos Aires (Argentina); Alvarez Castillo, J. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Alvarez-Muniz, J. [Universidad de Santiago de Compostela (Spain); Alves Batista, R. [Universidade Estadual de Campinas, IFGW, Campinas, SP (Brazil); Ambrosio, M.; Aramo, C. [Universita di Napoli ' Federico II' and Sezione INFN, Napoli (Italy); Aminaei, A. [IMAPP, Radboud University Nijmegen (Netherlands); Anchordoqui, L. [University of Wisconsin, Milwaukee, WI (United States); Antici' c, T. [Rudjer Boskovi' c Institute, 10000 Zagreb (Croatia); Collaboration: Pierre Auger Collaboration; and others

    2012-08-10

    The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E{sub {nu}} between 10{sup 17} eV and 10{sup 20} eV from point-like sources across the sky south of +55 Degree-Sign and north of -65 Degree-Sign declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth's crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of {approx}3.5 years of a full surface detector array for the Earth-skimming channel and {approx}2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. Assuming a differential neutrino flux k{sub PS} {center_dot} E {sup -2}{sub {nu}} from a point-like source, 90% confidence level upper limits for k{sub PS} at the level of Almost-Equal-To 5 Multiplication-Sign 10{sup -7} and 2.5 Multiplication-Sign 10{sup -6} GeV cm{sup -2} s{sup -1} have been obtained over a broad range of declinations from the searches for Earth-skimming and downward-going neutrinos, respectively.

  5. Fiscal 1996 survey report. `Ultra high electronic technology development promotion project` under consignment from NEDO; 1996 nendo kenkyu seika hokokusho. Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku jigyo `chosentan denshi gijutsu kaihatsu sokushin jigyo`

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    For the purpose of establishing ultra high technology of a next next generation level which is a basic technology in the electronic information field, a key to the realization of the high grade information society and a common technology base giving marked influences to the wide range industrial field, the R and D was started of ultra fine processing process technology, technologies on limit measuring/analysis/control and new functional electronic materials. Themes of the R and D are electronic beam direct picture drawing system technology, ultra short wavelength electromagnetic radiation patterning/system technology, ultra fine sensitizing technology to draw pictures on metal and crystal surfaces using ultra short wavelength laser beams, shading system technology of shading mask to be used to the process of drawing ultra high accuracy and complicated figures, ultra high tech plasma reactive measuring/analysis/control technologies which become the base of ultra thin films and ultra fine etching using plasma, ultra high tech cleaning base technology, ultra high sensitivity medium technology, new functional element/film formation technology, etc. 137 refs., 358 figs., 38 tabs.

  6. Fiscal 1997 survey report. `Ultra high electronic technology development promotion project` under consignment from NEDO; 1997 nendo kenkyu seika hokokusho. Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku jigyo `Chosentan denshi gijutsu kaihatsu sokushin jigyo`

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    For the purpose of establishing ultra high technology of a next next generation level, the R and D was conducted of ultra fine processing process technology, technologies on limit measuring/analysis/control and new functional electronic materials. Themes of the R and D are electronic beam direct picture drawing system technology, ultra short wavelength electromagnetic radiation patterning/system technology, ultra fine sensitizing technology, ultra high accuracy shading system technology, ultra high tech plasma reactive measuring/analysis/control technology, ultra high tech cleaning basic technology, ultra high sensitivity medium technology, new functional element/film formation technology, etc. This R and D is a greatly influential basic research in the whole industrial field, and therefore, it is necessary that researchers standing foremost in each field of industry/university/government join the project and that various R and D infrastructures are made the most of. For this, the concentrated joint research method and the dispersed joint research method are combined, and the R and D is being conduced by equal partnership of each researcher. 421 refs., 823 figs., 91 tabs.

  7. Ultra High Energy Cosmology with POLARBEAR

    CERN Document Server

    Keating, B; Boettger, D; Edwards, J; Fuller, G; Matsuda, F; Miller, N; Paar, H; Rebeiz, G; Schanning, I; Shimon, M; Stebor, N; Arnold, K; Flanigan, D; Holzapfel, W; Howard, J; Kermish, Z; Lee, A; Lungu, M; Myers, M; Nishino, H; O'Brient, R; Quealy, E; Reichardt, C; Richards, P; Shimmin, C; Steinbach, B; Suzuki, A; Zahn, O; Borrill, J; Cantalupo, C; Kisner, E; Linder, E; Sholl, M; Spieler, H; Anthony, A; Halverson, N; Errard, J; Fabbian, G; Jeune, M Le; Stompor, R; Jaffe, A; O'Dea, D; Chinone, Y; Hasegawa, M; Hazumi, M; Matsumura, T; Morii, H; Shimizu, A; Tomaru, T; Hyland, P; Dobbs, M; Ade, P; Grainger, W; Tucker, C

    2011-01-01

    Observations of the temperature anisotropy of the Cosmic Microwave Background (CMB) lend support to an inflationary origin of the universe, yet no direct evidence verifying inflation exists. Many current experiments are focussing on the CMB's polarization anisotropy, specifically its curl component (called "B-mode" polarization), which remains undetected. The inflationary paradigm predicts the existence of a primordial gravitational wave background that imprints a unique B-mode signature on the CMB's polarization at large angular scales. The CMB B-mode signal also encodes gravitational lensing information at smaller angular scales, bearing the imprint of cosmological large scale structures (LSS) which in turn may elucidate the properties of cosmological neutrinos. The quest for detection of these signals; each of which is orders of magnitude smaller than the CMB temperature anisotropy signal, has motivated the development of background-limited detectors with precise control of systematic effects. The POLARBEA...

  8. Recipe for attaining optimal energy resolution in inorganic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai; Koblov, Alexander [School of Engineering and IT, B-purple-12, Faculty of EHSE, Charles Darwin University, Darwin, NT 0909 (Australia)

    2012-12-15

    Using an approximate form of the density of excitation created within the track initiated by an incident {gamma} - photon on a scintillator, the light yield is derived as a function of linear, bimolecular and Auger radiative and quenching recombination rates. The non-proportionality in the yield is analysed as a function of the bimolecular and Auger quenching rates and also its dependence on the track radius is studied. An optimal combination of these quenching rates and track radius is presented to obtain a recipe for inventing a scintillator material with optimal energy resolution. The importance of the mobility of charge carriers in minimising the non-proportionality in a scintillator is also discussed (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Ultra High Temperature Ceramics for aerospace applications

    OpenAIRE

    Jankowiak, A.; Justin, J.F.

    2014-01-01

    Après relecture une erreur est apparue dans le document et doit être retiré; International audience; The Ultra High Temperature Ceramics (UHTCs) are of great interest for different engineering sectors and notably the aerospace industry. Indeed, hypersonic flights, re-entry vehicles, propulsion applications and so on, require new materials that can perform in oxidizing or corrosive atmospheres at temperatures higher than 2000°C and sometimes, for long life-time. To fulfil these requirements, U...

  10. Springback analysis of ultra high strength steel

    Science.gov (United States)

    Tenma, Kenji; Kina, Futoshi; Suzuki, Wataru

    2013-12-01

    It is an inevitable trend in the automotive industry to apply more and more high strength steels and even ultra-high strength steels. Even though these materials are more difficult to process the development time of forming tools must be reduced. In order to keep the development time under control, simulation tools are used to verify the forming process in advance. At Aoi Machine Industry a project has been executed to accurately simulate springback of ultra-high strength steels in order to reduce the tool tryout time. In the first phase of the project the simulation settings were optimized based on B-Pillar model A made of Dual Phase 980. In the second phase, it was verified with B-Pillar model B whether these simulation settings were usable as general setting. Results showed that with the right settings it is very well possible to accurately simulate springback of ultra-high strength steels. In the third phase the project the stamping of a B-Pillar of Dual Phase 1180 was studied.

  11. Design of Ultra High Performance Fiber Reinforced Concrete Shells

    DEFF Research Database (Denmark)

    Jepsen, Michael S.; Lambertsen, Søren Heide; Damkilde, Lars

    2013-01-01

    Fiber Reinforced Concrete shell. The major challenge in the design phase has been securing sufficient stiffness of the structure while keeping the weight at a minimum. The weight/stiffness issue has been investigated by means of the finite element method, to optimize the structure regarding overall......The paper treats the redesign of the float structure of the Wavestar wave energy converter. Previously it was designed as a glass fiber structure, but due to cost reduction requirements a redesign has been initiated. The new float structure will be designed as a double curved Ultra High Performance...

  12. Multi-Scale Porous Ultra High Temperature Ceramics

    Science.gov (United States)

    2015-01-08

    Final 3. DATES COVERED (From - To) 28-Mar-2013 - 27-Sep-2015 4. TITLE AND SUBTITLE Multi-Scale Porous Ultra High Temperature Ceramics ...report summarizes the main outcomes of research to develop multi-scale porosity Ultra High Temperature Ceramic materials. Processing conditions were...flights. 15. SUBJECT TERMS Ultra High Temperature Ceramics , Colloidal Powder Processing, Multi-scale Porous Materials, Lattice Monte

  13. Sintering of ultra high molecular weight polyethylene

    Indian Academy of Sciences (India)

    Sangeeta Hambir; J P Jog

    2000-06-01

    Ultra high molecular weight polyethylene (UHMWPE) is a high performance polymer having low coefficient of friction, good abrasion resistance, good chemical resistance etc. It is used in shipbuilding, textile industries and also in biomedical applications. UHMWPE is processed by powder processing technique because of its high melt viscosity at the processing temperature. Powder processing technique involves compaction of polymeric powder under pressure and sintering of the preforms at temperature above its melting point. In this study, we report our results on compaction and sintering behaviour of two grades of UHMWPE with reference to the powder morphology, sintering temperatures and strength development.

  14. The Bendability of Ultra High strength Steels

    Science.gov (United States)

    Hazra, S. K.; Efthymiadis, P.; Alamoudi, A.; Kumar, R. L. V.; Shollock, B.; Dashwood, R.

    2016-08-01

    Automotive manufacturers have been reducing the weight of their vehicles to meet increasingly stringent environmental legislation that reflects public demand. A strategy is to use higher strength materials for parts with reduced cross-sections. However, such materials are less formable than traditional grades. The frequent result is increased processing and piece costs. 3D roll forming is a novel and flexible process: it is estimated that a quarter of the structure of a vehicle can be made with a single set of tooling. Unlike stamping, this process requires material with low work hardening rates. In this paper, we present results of ultra high strength steels that have low elongation in a tension but display high formability in bending through the suppression of the necking response.

  15. Attainability and minimum energy of multiple-stage cascade membrane Systems

    KAUST Repository

    Alshehri, Ali

    2015-08-12

    Process design and simulation of multi-stage membrane systems have been widely studied in many gas separation systems. However, general guidelines have not been developed yet for the attainability and the minimum energy consumption of a multi-stage membrane system. Such information is important for conceptual process design and thus it is the topic of this work. Using a well-mixed membrane model, it was determined that the attainability curve of multi-stage systems is defined by the pressure ratio and membrane selectivity. Using the constant recycle ratio scheme, the recycle ratio can shift the attainability behavior between single-stage and multi-stage membrane systems. When the recycle ratio is zero, all of the multi-stage membrane processes will decay to a single-stage membrane process. When the recycle ratio approaches infinity, the required selectivity and pressure ratio reach their absolute minimum values, which have a simple relationship with that of a single-stage membrane process, as follows: View the MathML sourceSn=S1, View the MathML sourceγn=γ1, where n is the number of stages. The minimum energy consumption of a multi-stage membrane process is primarily determined by the membrane selectivity and recycle ratio. A low recycle ratio can significantly reduce the required membrane selectivity without substantial energy penalty. The energy envelope curve can provide a guideline from an energy perspective to determine the minimum required membrane selectivity in membrane process designs to compete with conventional separation processes, such as distillation.

  16. Mid-infrared ultra-high-Q resonators based on fluoride crystalline materials

    Science.gov (United States)

    Lecaplain, C.; Javerzac-Galy, C.; Gorodetsky, M. L.; Kippenberg, T. J.

    2016-11-01

    The unavailability of highly transparent materials in the mid-infrared has been the main limitation in the development of ultra-sensitive molecular sensors or cavity-based spectroscopy applications. Whispering gallery mode microresonators have attained ultra-high-quality (Q) factor resonances in the near-infrared and visible. Here we report ultra-high Q factors in the mid-infrared using polished alkaline earth metal fluoride crystals. Using an uncoated chalcogenide tapered fibre as a high-ideality coupler in the mid-infrared, we study via cavity ringdown technique the losses of BaF2, CaF2, MgF2 and SrF2 microresonators. We show that MgF2 is limited by multiphonon absorption by studying the temperature dependence of the Q factor. In contrast, in SrF2 and BaF2 the lower multiphonon absorption leads to ultra-high Q factors at 4.5 μm. These values correspond to an optical finesse of , the highest value achieved for any type of mid-infrared resonator to date.

  17. Delamination toughness of ultra high molecular weight polyethylene (UHMWPE composites

    Directory of Open Access Journals (Sweden)

    Casas-Rodriguez J.P.

    2012-08-01

    Full Text Available Ultra high molecular weight polyethylene (UHMWPE fibre reinforced composites are an important group of material for armours solutions, where their unique combination of properties could be utilized. A commonly observed failure mode in this kind of unidirectional laminated composites under impact ballistic is delamination between the composite layers. In the present study, an investigation on the delamination toughness behaviour exhibited by UHMWPE composites laminated was made. The interlaminar Mode II critical strain energy release rates of (UHMWPE fibre reinforced composites were characterized using the End Notch Flexural (ENF test. Critical strain energy release rate was obtained from the load – deflection test data using the beam theory expression. It was found that the energy release rate of the composite exhibited a very low value of around 60J/m2 using a moulding pressure of approximately 1200 psi. In order to analyse the delamination resistance of composite, the effects of changing the manufacture process variables and the use of a thermoplastic adhesive film in the composites were investigated. The composite laminates were produced by hot compressing moulding using a film-stacking procedure. It was found that the damage resistance of the UHMWPE composite was influenced by the manufacture method, which affects the Mode II interlaminar fracture toughness and the ballistic response of composites.

  18. Precise measurement of the absolute fluorescence yield of nitrogen in air. Consequences on the detection of ultra-high energy cosmic rays; Mesure precise du rendement absolu de la fluorescence de l'azote dans l'air. Consequences sur la detection des rayons cosmiques d'ultra-haute energie

    Energy Technology Data Exchange (ETDEWEB)

    Lefeuvre, G

    2006-07-15

    The study of the energy spectrum of ultra-high energy cosmic rays (E > 10{sup 20} eV) requires to determine the energy with much more precision than what is currently achieved. The shower of particles created in the atmosphere can be detected either by sampling particle on the ground, or by detecting the fluorescence induced by the excitation of nitrogen by shower electrons. At present, the measurement of the fluorescence is the simplest and the most reliable method, since it does not call upon hadronic physics laws at extreme energies, a field still inaccessible to accelerators. The precise knowledge of the conversion factor between deposited energy and the number of fluorescence photons produced (the yield) is thus essential. Up to now, it has been determined with an accuracy of 15 % only. This main goal of this work is to measure this yield to better than 5 per cent. To do this, 1 MeV electrons from a radioactive source excite nitrogen of the air. The accuracy has been reached thanks to the implementation of a new method for the absolute calibration of the photomultipliers detecting the photons, to better than 2 per cent. The fluorescence yield, measured and normalized to 0.85 MeV, 760 mmHg and 15 Celsius degrees, is (4.23 {+-} 0.20) photons per meter, or (20.46 {+-} 0.98) photons per deposited MeV. In addition, and for the first time, the absolute fluorescence spectrum of nitrogen excited by a source has been measured with an optical grating spectrometer. (author)

  19. Attainability and minimum energy of single-stage membrane and membrane/distillation hybrid processes

    KAUST Repository

    Alshehri, Ali

    2014-12-01

    As an energy-efficient separation method, membrane technology has attracted more and more attentions in many challenging separation processes. The attainability and the energy consumption of a membrane process are the two basic fundamental questions that need to be answered. This report aims to use process simulations to find: (1) at what conditions a single-stage membrane process can meet the separation task that is defined by product purity and recovery ratio and (2) what are the most important parameters that determine the energy consumption. To perform a certain separation task, it was found that both membrane selectivity and pressure ratio exhibit a minimum value that is defined only by product purity and recovery ratio. The membrane/distillation hybrid system was used to study the energy consumption. A shortcut method was developed to calculate the minimum practical separation energy (MPSE) of the membrane process and the distillation process. It was found that the MPSE of the hybrid system is only determined by the membrane selectivity and the applied transmembrane pressure ratio in three stages. At the first stage when selectivity is low, the membrane process is not competitive to the distillation process. Adding a membrane unit to a distillation tower will not help in reducing energy. At the second medium selectivity stage, the membrane/distillation hybrid system can help reduce the energy consumption, and the higher the membrane selectivity, the lower is the energy. The energy conservation is further improved as pressure ratio increases. At the third stage when both selectivity and pressure ratio are high, the hybrid system will change to a single-stage membrane unit and this change will cause significant reduction in energy consumption. The energy at this stage keeps decreasing with selectivity at slow rate, but slightly increases with pressure ratio. Overall, the higher the membrane selectivity, the more the energy is saved. Therefore, the two

  20. Uniaxial Compressive Properties of Ultra High Toughness Cementitious Composite

    Institute of Scientific and Technical Information of China (English)

    CAI Xiangrong; XU Shilang

    2011-01-01

    Uniaxial compression tests were conducted to characterize the main compressive performance of ultra high toughness cementitious composite(UHTCC)in terms of strength and toughness and to obtain its stress-strain relationships.The compressive strength investigated ranges from 30 MPa to 60 MPa.Complete stress-strain curves were directly obtained,and the strength indexes,including uniaxial compressive strength,compressive strain at peak stress,elastic modulus and Poisson's ratio,were calculated.The comparisons between UHTCC and matrix were also carried out to understand the fiber effect on the compressive strength indexes.Three dimensionless toughness indexes were calculated,which either represent its relative improvement in energy absorption capacity because of fiber addition or provide an indication of its behavior relative to a rigid-plastic material.Moreover,two new toughness indexes,which were named as post-crack deformation energy and equivalent compressive strength,were proposed and calculated with the aim at linking up the compressive toughness of UHTCC with the existing design concept of concrete.The failure mode was also given.The study production provides material characteristics for the practical engineering application of UHTCC.

  1. Fibrous Fillers to Manufacture Ultra High Ash/Performance Paper

    Energy Technology Data Exchange (ETDEWEB)

    Dr. VIjay K. Mathur

    2009-04-30

    The paper industry is one of the largest users of energy and emitters of CO2 in the US manufacturing industry. In addition to that, it is facing tremendous financial pressure due to lower cost imports. The fine paper industry has shrunk from 15 million tons per year production to 10 million tons per year in the last 5 years. This has resulted in mill closures and job loses. The AF&PA and the DOE formed a program called Agenda 2020 to help in funding to develop breakthrough technologies to provide help in meeting these challenges. The objectives of this project were to optimize and scale-up Fibrous Fillers technology, ready for commercial deployment and to develop ultra high ash/high performance paper using Fibrous Fillers. The goal was to reduce energy consumption, carbon footprint, and cost of manufacturing paper and related industries. GRI International (GRI) has been able to demonstrate the techno - economic feasibility and economic advantages of using its various products in both handsheets as well as in commercial paper mills. GRI has also been able to develop sophisticated models that demonstrate the effect of combinations of GRI's fillers at multiple filler levels. GRI has also been able to develop, optimize, and successfully scale-up new products for use in commercial paper mills.

  2. Biocompatibility of modified ultra-high-molecular-weight polyethylene

    Science.gov (United States)

    Novotná, Z.; Lacmanová, V.; Rimpelová, S.; Juřik, P.; Polívková, M.; Å vorčik, V.

    2016-09-01

    Ultra-high-molecular-weight polyethylene (UHMWPE, PE) is a synthetic polymer used for biomedical applications because of its high impact resistance, ductility and stability in contact with physiological fluids. Therefore this material is being used in human orthopedic implants such as total joint replacements. Surface modification of this material relates to changes of its surface hydrophilicity, energy, microstructure, roughness, and morphology, all influencing its biological response. In our recent work, PE was treated by an Ar+ plasma discharge and then grafted with biologically active polyethylene glycol in order to enhance adhesion and proliferation of mouse fibroblast (L929). The surface properties of pristine PE and its grafted counterparts were studied by goniometry (surface wettability). Furthermore, Atomic Force Microscopy was used to determine the surface morphology and roughness. The biological response of the L929 cell lines seeded on untreated and plasma treated PE matrices was quantified in terms of the cell adhesion, density, and metabolic activity. Plasma treatment leads to the ablation of the polymer surface layers. Plasma treatment and subsequent poly(ethylene glycol) grafting lead to dramatic changes in the polymer surface morphology and roughness. Biological tests, performed in vitro, show increased adhesion and proliferation of cells on modified polymers. Grafting with poly(ethylene glycol) increases cell proliferation compared to plasma treatment.

  3. Tensile and Flexural Properties of Ultra High Toughness Cemontious Composite

    Institute of Scientific and Technical Information of China (English)

    LI Hedong; XU Shilang; Christopher K Y Leung

    2009-01-01

    The tensile and flexural properties of polyvinyl alcohol(PVA)fiber reinforced ultra high toughness cementitious composite(UHTCC)were investigated.The composite,tested at the age of 14 d,28 d and 56 d,shows extremely remarkable pseudo strain hardening behavior,saturated mul-tiple cracking and ultra high ultimate strain capacity above 4%under uniaxial loading.Also,the cor-responding crack widths are controlled under 50 μm even at 56 days age.In the third point bending tests on thin plate specimens,the composite shows ultra high flexural ductility and multiple cracking on the tension surface.The high ultimate flexural strength/first tensile strength ratio of about 5 verifies the pseudo strain hardening behavior of UHTCC.SEM observation on fracture surfaces provides in-direct evidence of optimal design for the composite.

  4. Ultra-high Efficiency DC-DC Converter using GaN Devices

    DEFF Research Database (Denmark)

    Ramachandran, Rakesh

    2016-01-01

    The demands for high efficiency dc-dc power converters are increasing day by day in various applications such as telecommunication, data-centers, electric vehicles and various renewable energy systems. Silicon (Si) has been used as the semiconductor material in majority of the power devices...... properties of GaN devices can be utilized in power converters to make them more compact and highly efficient. This thesis entitled “Ultra-high Efficiency DC-DC Converter using GaN devices” focuses on achieving ultra-high conversion efficiency in an isolated dc-dc converter by the optimal utilization of Ga......N devices. Simple replacement of Si or SiC devices with GaN devices in the converter will not give an expected increase in efficiency or any improvement in the performance of the converter. The use of GaN devices has defined another dimension in the design of power converters, which mainly deals...

  5. Preliminary evaluation of ultra-high pitch computed tomography enterography

    Energy Technology Data Exchange (ETDEWEB)

    Hardie, Andrew D.; Horst, Nicole D.; Mayes, Nicholas [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston (United States)], E-mail: andrewdhardie@gmail.com

    2012-12-15

    Background. CT enterography (CTE) is a valuable tool in the management of patients with inflammatory bowel disease. Reducing imaging time, reduced motion artifacts, and decreased radiation exposure are important goals for optimizing CTE examinations. Purpose. To assess the potential impact of new CT technology (ultra-high pitch CTE) for the ability to reduce scan time and also potentially reduce radiation exposure while maintaining image quality. Material and Methods. This retrospective study compared 13 patients who underwent ultra-high pitch CTE with 25 patients who underwent routine CTE on the same CT scanner with identical radiation emission settings. Total scan time and radiation exposure were recorded for each patient. Image quality was assessed by measurement of image noise and also qualitatively by two independent observers. Results. Total scan time was significantly lower for patients who underwent ultra-high pitch CTE (2.1 s {+-} 0.2) than by routine CTE (18.6 s {+-} 0.9) (P < 0.0001). The mean radiation exposure for ultra-high pitch CTE was also significantly lower (10.1 mGy {+-} 1.0) than routine CTE (15.8 mGy {+-} 4.5) (P < 0.0001). No significant difference in image noise was found between ultra-high pitch CTE (16.0 HU {+-} 2.5) and routine CTE (15.5 HU {+-} 3.7) (P > 0.74). There was also no significant difference in image quality noted by either of the two readers. Conclusion. Ultra-high pitch CTE can be performed more rapidly than standard CTE and offers the potential for radiation exposure reduction while maintaining image quality.

  6. An Asymmetric Supercapacitor with Both Ultra-High Gravimetric and Volumetric Energy Density Based on 3D Ni(OH)2/MnO2@Carbon Nanotube and Activated Polyaniline-Derived Carbon.

    Science.gov (United States)

    Shen, Juanjuan; Li, Xiaocheng; Wan, Liu; Liang, Kun; Tay, Beng Kang; Kong, Lingbin; Yan, Xingbin

    2017-01-11

    Development of a supercapacitor device with both high gravimetric and volumetric energy density is one of the most important requirements for their practical application in energy storage/conversion systems. Currently, improvement of the gravimetric/volumetric energy density of a supercapacitor is restricted by the insufficient utilization of positive materials at high loading density and the inferior capacitive behavior of negative electrodes. To solve these problems, we elaborately designed and prepared a 3D core-shell structured Ni(OH)2/MnO2@carbon nanotube (CNT) composite via a facile solvothermal process by using the thermal chemical vapor deposition grown-CNTs as support. Owing to the superiorities of core-shell architecture in improving the service efficiency of pseudocapacitive materials at high loading density, the prepared Ni(OH)2/MnO2@CNT electrode demonstrated a high capacitance value of 2648 F g(-1) (1 A g(-1)) at a high loading density of 6.52 mg cm(-2). Coupled with high-performance activated polyaniline-derived carbon (APDC, 400 F g(-1) at 1 A g(-1)), the assembled Ni(OH)2/MnO2@CNT//APDC asymmetric device delivered both high gravimetric and volumetric energy density (126.4 Wh kg(-1) and 10.9 mWh cm(-3), respectively), together with superb rate performance and cycling lifetime. Moreover, we demonstrate an effective approach for building a high-performance supercapacitor with high gravimetric/volumetric energy density.

  7. Mid-Infrared ultra-high-Q resonators based on fluoride crystalline materials

    CERN Document Server

    Lecaplain, C; Gorodetsky, M L; Kippenberg, T J

    2016-01-01

    Decades ago, the losses of glasses in the near infrared (near-IR) were investigated in views of developments for optical telecommunications. Today, properties in the mid-infrared (mid-IR) are of interest for molecular spectroscopy applications. In particular, high-sensitivity spectroscopic techniques based on high-finesse mid-IR cavities hold high promise for medical applications. Due to exceptional purity and low losses, whispering gallery mode microresonators based on polished alkaline earth metal fluoride crystals (i.e the $\\mathrm{XF_2}$ family, where X $=$ Ca, Mg, Ba, Sr,...) have attained ultra-high quality (Q) factor resonances (Q$>$10$^{8}$) in the near-IR and visible spectral ranges. Here we report for the first time ultra-high Q factors in the mid-IR using crystalline microresonators. Using an uncoated chalcogenide (ChG) tapered fiber, light from a continuous wave quantum cascade laser (QCL) is efficiently coupled to several crystalline microresonators at 4.4 $\\mu$m wavelength. We measure the optica...

  8. MOF-derived crumpled-sheet-assembled perforated carbon cuboids as highly effective cathode active materials for ultra-high energy density Li-ion hybrid electrochemical capacitors (Li-HECs).

    Science.gov (United States)

    Banerjee, Abhik; Upadhyay, Kush Kumar; Puthusseri, Dhanya; Aravindan, Vanchiappan; Madhavi, Srinivasan; Ogale, Satishchandra

    2014-04-21

    Lithium ion hybrid capacitors (Li-HECs) have attracted significant attention for use in next generation advanced energy storage technologies to satisfy the demand of both high power density as well as energy density. Herein we demonstrate the use of very high surface area 3D carbon cuboids synthesized from a metal-organic framework (MOF) as a cathode material with Li₄Ti₅O₁₂ as the anode for high performance Li-HECs. The energy density of the cell is ∼65 W h kg(-1) which is significantly higher than that achievable with commercially available activated carbon (∼36 W h kg(-1)) and a symmetric supercapacitor based on the same MOF-derived carbon (MOF-DC ∼20 W h kg(-1)). The MOF-DC/Li₄Ti₅O₁₂ Li-HEC assembly also shows good cyclic performance with ∼82% of the initial value (∼25 W h kg(-1)) retained after 10,000 galvanostatic cycles under high rate cyclic conditions. This result clearly indicates that MOF-DC is a very promising candidate for future P-HEVs in a Li-HEC configuration.

  9. Ultra high performance liquid chromatography of seized drugs

    NARCIS (Netherlands)

    Lurie, I.S.

    2010-01-01

    The primary goal of this thesis is to investigate the use of ultra high performance liquid chromatography (UHPLC) for the analysis of seized drugs. This goal was largely achieved and significant progress was made in achieving improved separation and detection of drugs of forensic interest.

  10. Fact or friction: jumps at ultra high frequency

    NARCIS (Netherlands)

    K. Christensen; R. Oomen; M. Podolskij

    2011-01-01

    In this paper, we demonstrate that jumps in financial asset prices are not nearly as common as generally thought, and that they account for only a very small proportion of total return variation. We base our investigation on an extensive set of ultra high-frequency equity and foreign exchange rate d

  11. Ultra-high-resolution small-animal SPECT imaging

    NARCIS (Netherlands)

    Have, F. van der

    2007-01-01

    The main subject of this thesis is the development of the first two in a series of dedicated ultra-high resolution Single Photon Emission Computed Tomography (SPECT) systems (U-SPECT-I and II) for the imaging of distributions of radio-isotope labeled tracers in small laboratory animals such as mice

  12. Recent Advances in Ultra-High-Speed Optical Signal Processing

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Palushani, Evarist; Hu, Hao;

    2012-01-01

    We review recent advances in the optical signal processing of ultra-high-speed serial data signals up to 1.28 Tbit/s, with focus on applications of time-domain optical Fourier transformation. Experimental methods for the generation of symbol rates up to 1.28 Tbaud are also described....

  13. Ultra-high-speed serial optical communications: Enabling technologies

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen;

    2008-01-01

    This paper will present recently identified and demonstrated key technologies for ultra-high-speed serial communications. Certain key components such as stabilised highly non-linear fibre switches, periodically poled Lithium Niobate devices and semiconductor optical amplifiers will be described w...

  14. Ultra-high resolution electron microscopy

    Science.gov (United States)

    Oxley, Mark P.; Lupini, Andrew R.; Pennycook, Stephen J.

    2017-02-01

    The last two decades have seen dramatic advances in the resolution of the electron microscope brought about by the successful correction of lens aberrations that previously limited resolution for most of its history. We briefly review these advances, the achievement of sub-Ångstrom resolution and the ability to identify individual atoms, their bonding configurations and even their dynamics and diffusion pathways. We then present a review of the basic physics of electron scattering, lens aberrations and their correction, and an approximate imaging theory for thin crystals which provides physical insight into the various different imaging modes. Then we proceed to describe a more exact imaging theory starting from Yoshioka’s formulation and covering full image simulation methods using Bloch waves, the multislice formulation and the frozen phonon/quantum excitation of phonons models. Delocalization of inelastic scattering has become an important limiting factor at atomic resolution. We therefore discuss this issue extensively, showing how the full-width-half-maximum is the appropriate measure for predicting image contrast, but the diameter containing 50% of the excitation is an important measure of the range of the interaction. These two measures can differ by a factor of 5, are not a simple function of binding energy, and full image simulations are required to match to experiment. The Z-dependence of annular dark field images is also discussed extensively, both for single atoms and for crystals, and we show that temporal incoherence must be included accurately if atomic species are to be identified through matching experimental intensities to simulations. Finally we mention a few promising directions for future investigation.

  15. Soliton-based ultra-high speed optical communications

    Indian Academy of Sciences (India)

    Akira Hasegawa

    2001-11-01

    Multi-terabit/s, ultra-high speed optical transmissions over several thousands kilometers on fibers are becoming a reality. Most use RZ (Return to Zero) format in dispersion-managed fibers. This format is the only stable waveform in the presence of fiber Kerr nonlinearity and dispersion in all optical transmission lines with loss compensated by periodic amplifications. The nonlinear Schrödinger equation assisted by the split step numerical solutions is commonly used as the master equation to describe the information transfer in optical fibers. All these facts are the outcome of research on optical solitons in fibers in spite of the fact that the commonly used RZ format is not always called a soliton format. The overview presented here attempts to incorporate the role of soliton-based communications research in present day ultra-high speed communications.

  16. Ultra-high-speed Optical Signal Processing using Silicon Photonics

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Jensen, Asger Sellerup

    on silicon photonics. In particular we use nano-engineered silicon waveguides (nanowires) [1] enabling efficient phasematched four-wave mixing (FWM), cross-phase modulation (XPM) or self-phase modulation (SPM) for ultra-high-speed optical signal processing of ultra-high bit rate serial data signals. We show......— In supercomputers, the optical inter-connects are getting closer and closer to the processing cores. Today, a single supercomputer system has as many optical links as the whole worldwide web together, and it is envisaged that future computing chips will contain multiple electronic processor cores...... with a photonic layer on top to interconnect them. For such systems, silicon is an attractive candidate enabling both electronic and photonic control. For some network scenarios, it may be beneficial to use optical on-chip packet switching, and for high data-density environments one may take advantage...

  17. Photonic Technologies for Ultra-High-Speed Information Highways

    DEFF Research Database (Denmark)

    Bouchoule, S; Lèfevre, R.; Legros, E.;

    1999-01-01

    The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbed....... This paper reviews the current status of 40 Gbit/s TDM components and subsystem technologies achieved in HIGHWAY. The results of HIGHWAY 40 Gbit/s TDM systems and field tests will be reported in a subsequent paper. (C) 1999 Academic Press.......The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbeds...

  18. Boron Rich Solids Sensors, Ultra High Temperature Ceramics, Thermoelectrics, Armor

    CERN Document Server

    Orlovskaya, Nina

    2011-01-01

    The objective of this book is to discuss the current status of research and development of boron-rich solids as sensors, ultra-high temperature ceramics, thermoelectrics, and armor. Novel biological and chemical sensors made of stiff and light-weight boron-rich solids are very exciting and efficient for applications in medical diagnoses, environmental surveillance and the detection of pathogen and biological/chemical terrorism agents. Ultra-high temperature ceramic composites exhibit excellent oxidation and corrosion resistance for hypersonic vehicle applications. Boron-rich solids are also promising candidates for high-temperature thermoelectric conversion. Armor is another very important application of boron-rich solids, since most of them exhibit very high hardness, which makes them perfect candidates with high resistance to ballistic impact. The following topical areas are presented: •boron-rich solids: science and technology; •synthesis and sintering strategies of boron rich solids; •microcantileve...

  19. Ultra high frequency induction welding of powder metal compacts

    Energy Technology Data Exchange (ETDEWEB)

    Cavdar, U.; Gulsahin, I.

    2014-10-01

    The application of the iron based Powder Metal (PM) compacts in Ultra High Frequency Induction Welding (UHFIW) were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined. (Author)

  20. Ultra High-Energy Interaction of CR protons

    CERN Document Server

    Wibig, Tadeusz

    2008-01-01

    The recent Auger results suggest that although coincidences of arrival directions with 'nearby' AGN and HiRes discovery of the GZK cut-off indicate protons, the measured longitudinal propagation characteristics indicate heavy nuclei, if the conventional interaction model is correct. Something has to change! Our own view is that it is possible that the AGN -implied proton identification is not correct and that the extra galactic particles are, in fact, mainly 'heavies', in which case the interaction problem goes away. However, here we assume that the particles ARE protons and examine the possible consequences. Parameters discussed include the interaction mean-free-path, inelasticities and 'exotic' possibilities.

  1. EPOS Model and Ultra High Energy Cosmic Rays

    CERN Document Server

    Pierog, T

    2009-01-01

    Interpretation of extensive air showers (EAS) experiments results is strongly based on air shower simulations. The latter being based on hadronic interaction models, any new model can help for the understanding of the nature of cosmic rays. The EPOS model reproducing all major results of existing accelerator data (including detailed data of RHIC experiments) has been introduced in air shower simulation programs CORSIKA and CONEX few years ago. The new EPOS 1.99 has recently been updated taking into account the problem seen in EAS development using EPOS 1.61. We will show in details the relationship between some EPOS hadronic properties and EAS development, as well as the consequences on the model and finally on cosmic ray analysis.

  2. A focusable, convergent fast-electron beam from ultra-high-intensity laser-solid interactions

    CERN Document Server

    Scott, R H H

    2015-01-01

    A novel scheme for the creation of a convergent, or focussing, fast-electron beam generated from ultra-high-intensity laser-solid interactions is described. Self-consistent particle-in-cell simulations are used to demonstrate the efficacy of this scheme in two dimensions. It is shown that a beam of fast-electrons of energy 500 keV - 3 MeV propagates within a solid-density plasma, focussing at depth. The depth of focus of the fast-electron beam is controlled via the target dimensions and focussing optics.

  3. Ultra-High Performance ‘Ductile’ Concrete Technology Toward Sustainable Construction

    Directory of Open Access Journals (Sweden)

    Yen Lei Voo

    2011-07-01

    Full Text Available This paper briefly presents an overview of the material characteristics of a Malaysia blend of ultra-high performance ductile concrete (UHPdC know as DURA®. Examples of the environmental impact calculations of UHPdC structures compared to that of conventional reinforced concrete design are presented. The comparison studies show that many structures constructed from UHPdC are generally more environmentally sustainable than built of the conventional reinforced concrete with respect to the reduction of CO2 emissions and embodied energy. The enhanced durability of UHPdC also provides for significant improvements in the design life, which further supporting the concept of sustainable construction.

  4. Ultra-High-Contrast Laser Acceleration of Relativistic Electrons in Solid Targets

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, Drew Pitney [Univ. of California, San Diego, CA (United States)

    2013-01-01

    The cone-guided fast ignition approach to Inertial Con nement Fusion requires laser-accelerated relativistic electrons to deposit kilojoules of energy within an imploded fuel core to initiate fusion burn. One obstacle to coupling electron energy into the core is the ablation of material, known as preplasma, by laser energy proceeding nanoseconds prior to the main pulse. This causes the laser-absorption surface to be pushed back hundreds of microns from the initial target surface; thus increasing the distance that electrons must travel to reach the imploded core. Previous experiments have shown an order of magnitude decrease in coupling into surrogate targets when intentionally increasing the amount of preplasma. Additionally, for electrons to deposit energy within the core, they should have kinetic energies on the order of a few MeV, as less energetic electrons will be stopped prior to the core and more energetic electrons will pass through the core without depositing much energy. Thus a quantitative understanding of the electron energy spectrum and how it responds to varied laser parameters is paramount for fast ignition. For the rst time, this dissertation quantitatively investigates the acceleration of electrons using an ultra-high-contrast laser. Ultra-high-contrast lasers reduce the laser energy that reaches the target prior to the main pulse; drastically reducing the amount of preplasma. Experiments were performed in a cone-wire geometry relevant to fast ignition. These experiments irradiated the inner-tip of a Au cone with the laser and observed electrons that passed through a Cu wire attached to the outer-tip of the cone. The total emission of K x-rays is used as a diagnostic to infer the electron energy coupled into the wire. Imaging the x-ray emission allowed an e ective path-length of electrons within the wire to be determined, which constrained the electron energy spectrum. Experiments were carried out on the ultra-high-contrast Trident laser at Los

  5. Design Strategies for Ultra-high Efficiency Photovoltaics

    Science.gov (United States)

    Warmann, Emily Cathryn

    While concentrator photovoltaic cells have shown significant improvements in efficiency in the past ten years, once these cells are integrated into concentrating optics, connected to a power conditioning system and deployed in the field, the overall module efficiency drops to only 34 to 36%. This efficiency is impressive compared to conventional flat plate modules, but it is far short of the theoretical limits for solar energy conversion. Designing a system capable of achieving ultra high efficiency of 50% or greater cannot be achieved by refinement and iteration of current design approaches. This thesis takes a systems approach to designing a photovoltaic system capable of 50% efficient performance using conventional diode-based solar cells. The effort began with an exploration of the limiting efficiency of spectrum splitting ensembles with 2 to 20 sub cells in different electrical configurations. Incorporating realistic non-ideal performance with the computationally simple detailed balance approach resulted in practical limits that are useful to identify specific cell performance requirements. This effort quantified the relative benefit of additional cells and concentration for system efficiency, which will help in designing practical optical systems. Efforts to improve the quality of the solar cells themselves focused on the development of tunable lattice constant epitaxial templates. Initially intended to enable lattice matched multijunction solar cells, these templates would enable increased flexibility in band gap selection for spectrum splitting ensembles and enhanced radiative quality relative to metamorphic growth. The III-V material family is commonly used for multijunction solar cells both for its high radiative quality and for the ease of integrating multiple band gaps into one monolithic growth. The band gap flexibility is limited by the lattice constant of available growth templates. The virtual substrate consists of a thin III-V film with the desired

  6. Preparation for Ultra High Pure Indium Metal for Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Shashwat V. Joshi

    2014-11-01

    Full Text Available Ultra high pure Indium metal is extensively used in optoelectronic devices. Indium and its alloys become potential candidates in aerospace, defense and communication sectors. Purification of Indium has been done by Instrolec-200 Refiner followed by Directional Melting/ Freezing and Solidification Systems. Major targeted impurities are Metallic impurities Ag, Al, As, Bi, Ca, Cu, Fe, Ga, Ge, Mg, Pb, Sb, Si, Sn, and Zn. Purified Indium is characterized by analytical techniques Inductively Coupled Plasma- Optical Emission Spectrophotometry and Inductively Coupled Plasma- Mass Spectrometry.

  7. Design of Ultra-High Temperature Ceramics for Improved Performance

    Science.gov (United States)

    2009-02-28

    Hilmas, S. Zhu, J. Ridge, D.G. Fletcher, CO. Asma , O. Chazot, and J. Thomel, "Oxidation of ZrB2-SiC Ultra-High Temperature Ceramic Composites in...American Ceramic Society, elected September 2007 3. Univ. of New Mexico School of Engineering Distinguished Young Alumnus, October 2006 4. Faculty...Verona, Italy. 4. J. Marschall, D.A. Pejakovi, W.G. Fahrenholtz, G.E. Hilmas, S. Zhu, J. Ridge, D.G. Fletcher, CO. Asma , O. Chazot, and J. Thomel

  8. TRIAXIAL COMPRESSIVE STRENGTH OF ULTRA HIGH PERFORMANCE CONCRETE

    Directory of Open Access Journals (Sweden)

    Radoslav Sovják

    2013-12-01

    Full Text Available The aim of this work is to describe the strength of Ultra High Performance Concrete (UHPC under triaxial compression. The main goal is to find a trend in the triaxial compressive strength development under various values of confinement pressure. The importance of triaxial tests lies in the spatial loading of the sample, which simulates the real loading of the material in the structure better than conventional uniaxial strength tests. In addition, the authors describe a formulation process for UHPC that has been developed without using heat treatment, pressure or a special mixer. Only ordinary materials available commercially in the Czech Republic were utilized throughout the material design process.

  9. Systematic Calibration for Ultra-High Accuracy Inertial Measurement Units.

    Science.gov (United States)

    Cai, Qingzhong; Yang, Gongliu; Song, Ningfang; Liu, Yiliang

    2016-06-22

    An inertial navigation system (INS) has been widely used in challenging GPS environments. With the rapid development of modern physics, an atomic gyroscope will come into use in the near future with a predicted accuracy of 5 × 10(-6)°/h or better. However, existing calibration methods and devices can not satisfy the accuracy requirements of future ultra-high accuracy inertial sensors. In this paper, an improved calibration model is established by introducing gyro g-sensitivity errors, accelerometer cross-coupling errors and lever arm errors. A systematic calibration method is proposed based on a 51-state Kalman filter and smoother. Simulation results show that the proposed calibration method can realize the estimation of all the parameters using a common dual-axis turntable. Laboratory and sailing tests prove that the position accuracy in a five-day inertial navigation can be improved about 8% by the proposed calibration method. The accuracy can be improved at least 20% when the position accuracy of the atomic gyro INS can reach a level of 0.1 nautical miles/5 d. Compared with the existing calibration methods, the proposed method, with more error sources and high order small error parameters calibrated for ultra-high accuracy inertial measurement units (IMUs) using common turntables, has a great application potential in future atomic gyro INSs.

  10. Systematic Calibration for Ultra-High Accuracy Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Qingzhong Cai

    2016-06-01

    Full Text Available An inertial navigation system (INS has been widely used in challenging GPS environments. With the rapid development of modern physics, an atomic gyroscope will come into use in the near future with a predicted accuracy of 5 × 10−6°/h or better. However, existing calibration methods and devices can not satisfy the accuracy requirements of future ultra-high accuracy inertial sensors. In this paper, an improved calibration model is established by introducing gyro g-sensitivity errors, accelerometer cross-coupling errors and lever arm errors. A systematic calibration method is proposed based on a 51-state Kalman filter and smoother. Simulation results show that the proposed calibration method can realize the estimation of all the parameters using a common dual-axis turntable. Laboratory and sailing tests prove that the position accuracy in a five-day inertial navigation can be improved about 8% by the proposed calibration method. The accuracy can be improved at least 20% when the position accuracy of the atomic gyro INS can reach a level of 0.1 nautical miles/5 d. Compared with the existing calibration methods, the proposed method, with more error sources and high order small error parameters calibrated for ultra-high accuracy inertial measurement units (IMUs using common turntables, has a great application potential in future atomic gyro INSs.

  11. Ultra-high pressure water jet: Baseline report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-31

    The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of the outdoor environment where the testing demonstration took place. In addition, other areas of concern found were arm-hand vibration, ergonomics, heat stress, tripping hazards, electrical hazards, lockout/tagout, fall hazards, slipping hazards, hazards associated with the high pressure water, and hazards associated with air pressure systems.

  12. Nonresonant Metamaterials with an Ultra-High Permittivity

    Institute of Scientific and Technical Information of China (English)

    HE Xiao-Yang; CHEN Qi; LI Lin-Cui; YANG Chun; LI Biao; ZHOU Bang-Hua; TANG Chuan-Xiang

    2011-01-01

    @@ A nonresonant structure composed of metal cut-wires for realization of metamaterials is proposed.This kind of metamaterial works at an ultra broad bandwidth with uniform permittivity.Theoretical analysis and numerical simulations are carried out to study this inclusion and expression for the effective permittivity is given.Several methods are studied to enhance the permittivity and a nonresonant metamaterial with an ultra-high permittivity is obtained.A demonstration shows that the permittivity of this metamaterial can be as high as 145.%A nonresonant structure composed of metal cut-wires for realization of metamaterials is proposed. This kind of metamaterial works at an ultra broad bandwidth with uniform permittivity. Theoretical analysis and numerical simulations are carried out to study this inclusion and expression for the effective permittivity is given. Several methods are studied to enhance the permittivity and a nonresonant metamaterial with an ultra-high permittivity is obtained. A demonstration shows that the permittivity of this metamaterial can be as high as 145.

  13. Challenges and prospects for wind energy to attain 20% grid penetration by 2020 in India

    DEFF Research Database (Denmark)

    Madsen, Peter Hauge; Natarajan, Anand

    2011-01-01

    With wind energy being the most realistic large-scale renewable energy source in the near future, we examine the target for wind energy penetration in India for 2020. Achieving the target set by the Indian Wind Power Association of 20% wind power grid penetration by 2020 will act as a lighthouse......-scale integration of wind power. In the article, we discuss the trends in the development of wind energy and the factors which we consider decisive for the development of wind power in India. Experiences and policies from Europe and Denmark, where wind power already today contributes 20% to the total electricity...

  14. Improving distillation method and device of tritiated water analysis for ultra high decontamination efficiency.

    Science.gov (United States)

    Fang, Hsin-Fa; Wang, Chu-Fang; Lin, Chien-Kung

    2015-12-01

    It is important that monitoring environmental tritiated water for understanding the contamination dispersion of the nuclear facilities. Tritium is a pure beta radionuclide which is usually measured by Liquid Scintillation Counting (LSC). The average energy of tritum beta is only 5.658 keV that makes the LSC counting of tritium easily be interfered by the beta emitted by other radionuclides. Environmental tritiated water samples usually need to be decontaminated by distillation for reducing the interference. After Fukushima Nucleaer Accident, the highest gross beta concentration of groundwater samples obtained around Fukushima Daiichi Nuclear Power Station is over 1,000,000 Bq/l. There is a need for a distillation with ultra-high decontamination efficiency for environmental tritiated water analysis. This study is intended to improve the heating temperature control for better sub-boiling distillation control and modify the height of the container of the air cooling distillation device for better fractional distillation effect. The DF of Cs-137 of the distillation may reach 450,000 which is far better than the prior study. The average loss rate of the improved method and device is about 2.6% which is better than the bias value listed in the ASTM D4107-08. It is proven that the modified air cooling distillation device can provide an easy-handling, water-saving, low cost and effective way of purifying water samples for higher beta radionuclides contaminated water samples which need ultra-high decontamination treatment.

  15. Magnetic resonance imaging and spectroscopy at ultra high fields

    Energy Technology Data Exchange (ETDEWEB)

    Neuberger, Thomas

    2009-06-23

    The goal of the work presented in this thesis was to explore the possibilities and limitations of MRI / MRS using an ultra high field of 17.6 tesla. A broad range of specific applications and MR methods, from MRI to MRSI and MRS were investigated. The main foci were on sodium magnetic resonance spectroscopic imaging of rodents, magnetic resonance spectroscopy of the mouse brain, and the detection of small amounts of iron labeled stem cells in the rat brain using MRI Sodium spectroscopic imaging was explored since it benefits tremendously from the high magnetic field. Due to the intrinsically low signal in vivo, originating from the low concentrations and short transverse relaxation times, only limited results have been achieved by other researchers until now. Results in the literature include studies conducted on large animals such as dogs to animals as small as rats. No studies performed on mice have been reported, despite the fact that the mouse is the most important laboratory animal due to the ready availability of transgenic strains. Hence, this study concentrated on sodium MRSI of small rodents, mostly mice (brain, heart, and kidney), and in the case of the brain on young rats. The second part of this work concentrated on proton magnetic resonance spectroscopy of the rodent brain. Due to the high magnetic field strength not only the increasing signal but also the extended spectral resolution was advantageous for such kind of studies. The difficulties/limitations of ultra high field MRS were also investigated. In the last part of the presented work detection limits of iron labeled stem cells in vivo using magnetic resonance imaging were explored. The studies provided very useful benchmarks for future researchers in terms of the number of labeled stem cells that are required for high-field MRI studies. Overall this work has shown many of the benefits and the areas that need special attention of ultra high fields in MR. Three topics in MRI, MRS and MRSI were

  16. Ultra-high current density thin-film Si diode

    Science.gov (United States)

    Wang, Qi

    2008-04-22

    A combination of a thin-film .mu.c-Si and a-Si:H containing diode structure characterized by an ultra-high current density that exceeds 1000 A/cm.sup.2, comprising: a substrate; a bottom metal layer disposed on the substrate; an n-layer of .mu.c-Si deposited the bottom metal layer; an i-layer of .mu.c-Si deposited on the n-layer; a buffer layer of a-Si:H deposited on the i-layer, a p-layer of .mu.c-Si deposited on the buffer layer; and a top metal layer deposited on the p-layer.

  17. Ultra-high-speed optical and electronic distributed devices

    Energy Technology Data Exchange (ETDEWEB)

    Hietala, V.M.; Plut, T.A.; Kravitz, S.H.; Vawter, G.A.; Wendt, J.R.; Armendariz, M.G.

    1995-08-01

    This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

  18. Ultra-high-Q nanobeam cavity design in Diamond

    CERN Document Server

    Bayn, Igal; Kalish, Rafi

    2010-01-01

    A novel nanobeam design with a triangular cross-section is proposed. This design makes possible implementing nanocavities with improved optical properties. The dependence of a diamond-based cavity quality factor Q and mode volume Vm on geometry parameter space are studied via 3D FDTD computations. An ultra-high-Q cavity with Q\\aprox 2.51 \\times 10^6 and Vm=1.06 \\times ({\\lambda}/n)^3 is predicted. The mode preferential radiation is upward. The implications on the potential applications are discussed. The proposed nanobeam enables fabrication of the cavity without relying on a pre-existing free-standing diamond membrane as required in most previous approaches.

  19. Low velocity impact behaviour of ultra high strength concrete panels

    Indian Academy of Sciences (India)

    Smitha Gopinath; R Ayashwarya; V Ramesh Kumar; Prabhat Ranjan Prem; A Rama Chandra Murthy; C K Madheswaran; R Nagesh Iyer

    2014-12-01

    This paper presents the results of an investigation carried out on Ultra High Strength Concrete (UHSC) panels subjected to low velocity projectile impact to assess impact resistance. UHSC panel of size 350 × 350 mm and thickness 15 mm is studied under drop weight impact loading for three different pre-determined drop heights ranging from 100 mm to 300 mm. The response of UHSC panel in terms of acceleration vs time is obtained experimentally. Numerical model has been developed to simulate the impact behaviour of UHSC panel. The Brittle cracking model is used to simulate the behaviour of UHSC panel under impact loading and to perform parametric studies by varying the volume fraction of steel fibres.

  20. Achieving Mixtures of Ultra-High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Mircea POPA

    2013-07-01

    Full Text Available Ultra-High Performance Concrete (UHPC is a relatively new concrete. According to [11] UHPC is that concrete which features compressive strength over C100/115 class. Up to this point standards for this type of concrete were not adopted, although its characteristic strength exceeds those specified in [33]. Its main property is high compressive strength. This provides the possibility of reducing the section of elements (beams or columns made of this type of concrete, while the load capacity remains high. The study consists in blending mixtures of UHPC made of varying proportions of materials. The authors have obtained strengths of up to 160 MPa. The materials used are: Portland cement, silica fume, quartz powder, steel fibers, superplasticiser, sand and crushed aggregate for concrete - andesite.

  1. Physicochemical features of ultra-high viscosity alginates.

    Science.gov (United States)

    Storz, Henning; Müller, Kilian J; Ehrhart, Friederike; Gómez, Ivan; Shirley, Stephen G; Gessner, Petra; Zimmermann, Gertraud; Weyand, Esther; Sukhorukov, Vladimir L; Forst, Thomas; Weber, Matthias M; Zimmermann, Heiko; Kulicke, Werner-Michael; Zimmermann, Ulrich

    2009-05-26

    The physicochemical characteristics of the ultra-high viscosity and highly biocompatible alginates extracted from Lessonia nigrescens (UHV(N)) and Lessonia trabeculata (UHV(T)) were analyzed. Fluorescence and (1)H NMR spectroscopies, viscometry, and multi-angle light scattering (MALS) were used for elucidation of the chemical structure, molar mass, and coil size. The sequential structures from NMR spectroscopy showed high guluronate content for UHV(T), but low for UHV(N). Intrinsic viscosity [eta] measurements exhibited unusual high values (up to 2750 mL/g), whereas [eta] of a commercial alginate was only about 970 mL/g. MALS batch measurements of the UHV-alginates yielded ultra-high values of the weight average molar mass (M(w) up to 1.1x10(6) g/mol) and of the z-average gyration radius (R(G)(z) up to 191 nm). The M(w) and R(G)(z) distributions of UHV-alginates and of ultrasonically degraded fractions were determined using size exclusion chromatography combined with MALS and asymmetrical flow-field-flow fractionation. The M(w) dependency of [eta] and R(G)(z) could be described by [eta]=0.059xM(w)(0.78) and R(G)(z)=0.103xM(w)(x). (UHV(N): x=0.52; UHV(T): x=0.53) indicating that the monomer composition has no effect on coil expansion. Therefore, the equations can be used to calculate M(w) and R(G)(z) values of UHV(T)- and UHV(N)-alginate mixtures as used in immunoisolation. Furthermore, the simple and inexpensive capillary viscometry can be used for real-time validation of the extraction and purification process of the UHV-alginates.

  2. An Ultra-High Gradient Cherenkov Wakefield Acceleration Experiment at SLAC FFTB

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, J.B.; Hoover, S.; Hogan, M.J.; Muggli, P.; Thompson, M.; Travish, G.; Yoder, R.; /UCLA /SLAC /Southern California U.

    2005-08-02

    The creation of ultra-high current, ultra-short pulse beams Q=3 nC, {sigma}{sub z} = 20{micro}m at the SLAC FFTB has opened the way for very high gradient plasma wakefield acceleration experiments. We study here the use of these beams in a proposed Cherenkov wakefield experiment, where one may excite electromagnetic wakes in a simple dielectric tube with inner diameter of few 100 microns that exceed the GV/m level. We discuss the scaling of the fields with design geometric design parameters, and choice of dielectric. We also examine measurable aspects of the experiment, such as the total coherent Cerenkov radiation energy one may collect, and the expected aspects of dielectric breakdown at high fields.

  3. Monte Carlo simulations of ultra high vacuum and synchrotron radiation for particle accelerators

    CERN Document Server

    AUTHOR|(CDS)2082330; Leonid, Rivkin

    With preparation of Hi-Lumi LHC fully underway, and the FCC machines under study, accelerators will reach unprecedented energies and along with it very large amount of synchrotron radiation (SR). This will desorb photoelectrons and molecules from accelerator walls, which contribute to electron cloud buildup and increase the residual pressure - both effects reducing the beam lifetime. In current accelerators these two effects are among the principal limiting factors, therefore precise calculation of synchrotron radiation and pressure properties are very important, desirably in the early design phase. This PhD project shows the modernization and a major upgrade of two codes, Molflow and Synrad, originally written by R. Kersevan in the 1990s, which are based on the test-particle Monte Carlo method and allow ultra-high vacuum and synchrotron radiation calculations. The new versions contain new physics, and are built as an all-in-one package - available to the public. Existing vacuum calculation methods are overvi...

  4. Single and Multiple Dynamic Impacts Behaviour of Ultra-high Performance Cementitious Composite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wenhua; ZHANG Yunsheng; ZHANG Guorong

    2011-01-01

    Single and multiple dynamic impacts tests were conducted on ultra-high performance cementitious composite (UHPCC) with various volume fractions of steel fibers (0,1%,2%,3%,4%) by using the split hopkinson pressure bar (SHPB).Besides,the ultrasonic velocity method was used to test the damage on specimens caused by dynamic impacts.For single dynamic impact,the data suggest that UHPCC obviously presents dynamic strength enhancement.With increasing of strain rate,the peak stress and peak strain increase rapidly.For multiple dynamic impacts,the results show that addition of steel fibers can obviously enhance the properties of UHPCC to resist the repeated dynamic impacts.Firstly,the number of impacts sharply increases with the increasing of volume fraction of steel fibers.Secondly,the energy absorption ability linearly increases with addition of steel fibers.Thirdly,the steel fibers can prevent the disruption phenomenon and maintain the integrity of specimen.

  5. An Efficient, Movable Single-Particle Detector for Use in Cryogenic Ultra-High Vacuum Environments

    CERN Document Server

    Spruck, Kaija; Fellenberger, Florian; Grieser, Manfred; von Hahn, Robert; Klinkhamer, Vincent; Novotný, Oldřich; Schippers, Stefan; Vogel, Stephen; Wolf, Andreas; Krantz, Claude

    2014-01-01

    A compact, highly efficient single-particle counting detector for ions of keV/u kinetic energy, movable by a long-stroke mechanical translation stage, has been developed at the Max-Planck-Institut f\\"ur Kernphysik (Max Planck Institute for Nuclear Physics, MPIK). Both, detector and translation mechanics, can operate at ambient temperatures down to $\\sim$ 10 K and consist fully of ultra-high vacuum (UHV) compatible, high-temperature bakeable and non-magnetic materials. The set-up is designed to meet the technical demands of MPIK's Cryogenic Storage Ring (CSR). We present a series of functional tests that demonstrate full suitability for this application and characterise the set-up with regard to its particle detection efficiency.

  6. Silicon-graphene conductive photodetector with ultra-high responsivity

    Science.gov (United States)

    Liu, Jingjing; Yin, Yanlong; Yu, Longhai; Shi, Yaocheng; Liang, Di; Dai, Daoxin

    2017-01-01

    Graphene is attractive for realizing optoelectronic devices, including photodetectors because of the unique advantages. It can easily co-work with other semiconductors to form a Schottky junction, in which the photo-carrier generated by light absorption in the semiconductor might be transported to the graphene layer efficiently by the build-in field. It changes the graphene conduction greatly and provides the possibility of realizing a graphene-based conductive-mode photodetector. Here we design and demonstrate a silicon-graphene conductive photodetector with improved responsivity and response speed. An electrical-circuit model is established and the graphene-sheet pattern is designed optimally for maximizing the responsivity. The fabricated silicon-graphene conductive photodetector shows a responsivity of up to ~105 A/W at room temperature (27 °C) and the response time is as short as ~30 μs. The temperature dependence of the silicon-graphene conductive photodetector is studied for the first time. It is shown that the silicon-graphene conductive photodetector has ultra-high responsivity when operating at low temperature, which provides the possibility to detect extremely weak optical power. For example, the device can detect an input optical power as low as 6.2 pW with the responsivity as high as 2.4 × 107 A/W when operating at ‑25 °C in our experiment.

  7. Nano-porous ultra-high specific surface ultrafine fibers

    Institute of Scientific and Technical Information of China (English)

    LI Xinsong; NIE Guangyu

    2004-01-01

    Nano-porous ultra-high specific surface ultrafine fibers are created by the method of "electrospinning-phase separation-leaching" (EPL) for the first time. First of all, polymer solutions of polyacrylonitrile (PAN) and polyvinylpyrrolidone (PVP) blends dissolved in co-solvent are electrospun to make ultrafine fibers when charged to high voltages. The incompatibility of PAN and PVP induces phase separation to form microdomains of PVP in the polymer blend ultrafine fibers. Then, PVP microdomains in the blend fibers are leached out in water, and porous PAN ultrafine fibers are obtained. Lastly, the surface and cross-section of the porous ultrafine fibers are observed in detail by field emission scanning electron microscope (FESEM), and the specific surface of the ultrafine fibers is measured by means of nitrogen absorption. With increasing the content of PVP, the specific surface area of the ultrafine fibers increases apparently. The specific surface area of the porous ultrafine fibers with the diameter of 2130 nm is more than 70 m2·g-1. The cross-section of the PAN porous ultrafine fibers after leaching of PVP microdomains from polymer blend fibers with the feed ratio of PAN/PVP of 10/20 shows the characteristic of porous structure with pore diameter of ca 30 nm according to FESEM photo.

  8. Ultra-high Burst Strength of CVD Graphene Membranes

    Science.gov (United States)

    Wang, Luda; Boutilier, Michael; Kidambi, Piran; Karnik, Rohit; Microfluidics; Nanofluidics Research Lab Team

    2015-11-01

    Porous graphene membranes have significant potential in gas separation, water desalination and nanofiltration. Understanding the mechanical strength of porous graphene is crucial because membrane separations can involve high pressures. We studied the burst strength of CVD graphene membrane placed on porous support at applied pressures up to 100 bar by monitoring the gas flow rate across the membrane as a function of pressure. Increase of gas flow rate with pressure allowed for extraction of the burst fraction of graphene as it failed under increasing pressure. We also studied the effect of sub-nanometer pores on the ability of graphene to withstand pressure. The results showed that porous graphene membranes can withstand pressures comparable to or even higher than the >50 bar pressures encountered in water desalination, with non-porous CVD graphene exhibiting even higher mechanical strength. Our study shows that porous polycrystalline CVD graphene has ultra-high burst strength under applied pressure, suggesting the possibility for its use in high-pressure membrane separations. Principal Investigator

  9. Silicon-graphene conductive photodetector with ultra-high responsivity

    Science.gov (United States)

    Liu, Jingjing; Yin, Yanlong; Yu, Longhai; Shi, Yaocheng; Liang, Di; Dai, Daoxin

    2017-01-01

    Graphene is attractive for realizing optoelectronic devices, including photodetectors because of the unique advantages. It can easily co-work with other semiconductors to form a Schottky junction, in which the photo-carrier generated by light absorption in the semiconductor might be transported to the graphene layer efficiently by the build-in field. It changes the graphene conduction greatly and provides the possibility of realizing a graphene-based conductive-mode photodetector. Here we design and demonstrate a silicon-graphene conductive photodetector with improved responsivity and response speed. An electrical-circuit model is established and the graphene-sheet pattern is designed optimally for maximizing the responsivity. The fabricated silicon-graphene conductive photodetector shows a responsivity of up to ~105 A/W at room temperature (27 °C) and the response time is as short as ~30 μs. The temperature dependence of the silicon-graphene conductive photodetector is studied for the first time. It is shown that the silicon-graphene conductive photodetector has ultra-high responsivity when operating at low temperature, which provides the possibility to detect extremely weak optical power. For example, the device can detect an input optical power as low as 6.2 pW with the responsivity as high as 2.4 × 107 A/W when operating at −25 °C in our experiment. PMID:28106084

  10. Ultra High Temperature Ceramics' Processing Routes and Microstructures Compared

    Science.gov (United States)

    Gusman, Michael; Stackpoole, Mairead; Johnson, Sylvia; Gasch, Matt; Lau, Kai-Hung; Sanjurjo, Angel

    2009-01-01

    Ultra High Temperature Ceramics (UHTCs), such as HfB2 and ZrB2 composites containing SiC, are known to have good thermal shock resistance and high thermal conductivity at elevated temperatures. These UHTCs have been proposed for a number of structural applications in hypersonic vehicles, nozzles, and sharp leading edges. NASA Ames is working on controlling UHTC properties (especially, mechanical properties, thermal conductivity, and oxidation resistance) through processing, composition, and microstructure. In addition to using traditional methods of combining additives to boride powders, we are preparing UHTCs using coat ing powders to produce both borides and additives. These coatings and additions to the powders are used to manipulate and control grain-boundary composition and second- and third-phase variations within the UHTCs. Controlling the composition of high temperature oxidation by-products is also an important consideration. The powders are consolidated by hot-pressing or field-assisted sintering (FAS). Comparisons of microstructures and hardness data will be presented.

  11. Nanoporous ultra-high specific surface inorganic fibres

    Science.gov (United States)

    Kanehata, Masaki; Ding, Bin; Shiratori, Seimei

    2007-08-01

    Nanoporous inorganic (silica) nanofibres with ultra-high specific surface have been fabricated by electrospinning the blend solutions of poly(vinyl alcohol) (PVA) and colloidal silica nanoparticles, followed by selective removal of the PVA component. The configurations of the composite and inorganic nanofibres were investigated by changing the average silica particle diameters and the concentrations of colloidal silica particles in polymer solutions. After the removal of PVA by calcination, the fibre shape of pure silica particle assembly was maintained. The nanoporous silica fibres were assembled as a porous membrane with a high surface roughness. From the results of Brunauer-Emmett-Teller (BET) measurements, the BET surface area of inorganic silica nanofibrous membranes was increased with the decrease of the particle diameters. The membrane composed of silica particles with diameters of 15 nm showed the largest BET surface area of 270.3 m2 g-1 and total pore volume of 0.66 cm3 g-1. The physical absorption of methylene blue dye molecules by nanoporous silica membranes was examined using UV-vis spectrometry. Additionally, the porous silica membranes modified with fluoroalkylsilane showed super-hydrophobicity due to their porous structures.

  12. Nanoporous ultra-high specific surface inorganic fibres

    Energy Technology Data Exchange (ETDEWEB)

    Kanehata, Masaki [Faculty of Science and Technology, Keio University, Yokohama 223-8522 (Japan); Ding Bin [Fiber and Polymer Science, University of California, Davis, CA 95616 (United States); Shiratori, Seimei [Faculty of Science and Technology, Keio University, Yokohama 223-8522 (Japan)

    2007-08-08

    Nanoporous inorganic (silica) nanofibres with ultra-high specific surface have been fabricated by electrospinning the blend solutions of poly(vinyl alcohol) (PVA) and colloidal silica nanoparticles, followed by selective removal of the PVA component. The configurations of the composite and inorganic nanofibres were investigated by changing the average silica particle diameters and the concentrations of colloidal silica particles in polymer solutions. After the removal of PVA by calcination, the fibre shape of pure silica particle assembly was maintained. The nanoporous silica fibres were assembled as a porous membrane with a high surface roughness. From the results of Brunauer-Emmett-Teller (BET) measurements, the BET surface area of inorganic silica nanofibrous membranes was increased with the decrease of the particle diameters. The membrane composed of silica particles with diameters of 15 nm showed the largest BET surface area of 270.3 m{sup 2} g{sup -1} and total pore volume of 0.66 cm{sup 3} g{sup -1}. The physical absorption of methylene blue dye molecules by nanoporous silica membranes was examined using UV-vis spectrometry. Additionally, the porous silica membranes modified with fluoroalkylsilane showed super-hydrophobicity due to their porous structures.

  13. Minimax risks for sparse regressions: Ultra-high-dimensional phenomenons

    CERN Document Server

    Verzelen, Nicolas

    2010-01-01

    Consider the standard linear regression model $Y=X\\theta+\\epsilon$, where $Y\\in R^n$ is a response vector, $X\\in R^{n\\times p}$ is a design matrix, $\\theta\\in R^p$ is the unknown regression vector, and $\\epsilon\\sim N(0_p,\\sigma^2I_p)$ is a Gaussian noise. Numerous work have been devoted to building efficient estimators of $\\theta$ when $p$ is much larger than $n$. In such a situation, a classical approach amounts to assume that $\\theta$ is approximately sparse. This paper studies the minimax risks of estimation and testing over $k$-sparse vectors $\\theta$. These bounds shed light on the limitations due to high-dimensionality. The results encompass the problem of prediction (estimation of $X\\theta$), the inverse problem (estimation of $\\theta$) and linear testing (test of a linear hypothesis on $\\theta$). Interestingly, an elbow effect occurs when the number of variables $p$ becomes larger than $k\\exp(n/k)$. Indeed, the minimax risks and hypothesis separation distances blow up in this ultra-high dimensional s...

  14. Radiation crosslinking of ultra high molecular weigh polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Phil Hyun; Nho, Young Chang [KAERI, Taejon (Korea, Republic of)

    2000-05-01

    The effect of {gamma}-irradiation on the thermal and mechanical properties of ultra high molecular weight polyethylene (UHMWPE) used in orthopedic implants was investigated. UHMWPE was recrystallized with different cooling conditions for the purpose of enhancing the crosslinking extent of the polymer after {gamma}-irradiation. UHMWPE was irradiated with gamma ray to a dosage of 10 kGy to 500 kGy in air and nitrogen atmosphere. Differential scanning calorimetry, tensile characterization, creep deformity and wear were examined to determine the mechanical properties of the irradiated UHMWPE specimens. The crystallinity of the irradiated samples was increased with irradiation dose. The irradiated UHMWPE after recrystallization in a quenching condition had a higher crosslinking extent compared with the irradiated UHMWPE after slowly cooling. The irradiated UHMWPE after quenching had a lower wear rate than the irradiated UHMWPE after recrystallization in a slowly cooling condition, and the wear rate of UHMWPE decreased with irradiation dose up to 250kGy, which showed about 40% of the wear rate of nonirradiated UHMWPE.

  15. Tecnologia radio cognitiva en la banda ultra high frequency (UHF

    Directory of Open Access Journals (Sweden)

    Hernán Paz Penagos

    2014-01-01

    Full Text Available Mobile cellular communication companies in Colombia require more spectrum resources to expand their portfolio of services. However, additional frequency bands for that particular purpose are scarce, yet it is well known that there are many underutilized licensed bands. Therefore new radio technologies are being studied in order to solve this problem, e.g. Software Defined Radio SDR Cognitive Radio CR and Dynamic Spectrum Access DSA. These strategies recommend mobility across the radio spectrum to meet various needs and achieve greater efficiency when managing such a scarce resource. In this context, a case study is presented in an attempt to examine the require¬ments that must be met for the implementation of cognitive radio networks in Bogota. The case study includes evaluation for the possibility of migration from cellular communications to cognitive radio since the bands assigned to UltraHigh Frequency UHF television offer possible free-of-interference coexistence between the two services (i.e. Cellular and TV. The study shows feasibility to migration; however, the implementations of cognitive radio need availability of hardware, software and flexible radio platforms.

  16. Achieving ultra-high temperatures with a resistive emitter array

    Science.gov (United States)

    Danielson, Tom; Franks, Greg; Holmes, Nicholas; LaVeigne, Joe; Matis, Greg; McHugh, Steve; Norton, Dennis; Vengel, Tony; Lannon, John; Goodwin, Scott

    2016-05-01

    The rapid development of very-large format infrared detector arrays has challenged the IR scene projector community to also develop larger-format infrared emitter arrays to support the testing of systems incorporating these detectors. In addition to larger formats, many scene projector users require much higher simulated temperatures than can be generated with current technology in order to fully evaluate the performance of their systems and associated processing algorithms. Under the Ultra High Temperature (UHT) development program, Santa Barbara Infrared Inc. (SBIR) is developing a new infrared scene projector architecture capable of producing both very large format (>1024 x 1024) resistive emitter arrays and improved emitter pixel technology capable of simulating very high apparent temperatures. During earlier phases of the program, SBIR demonstrated materials with MWIR apparent temperatures in excess of 1400 K. New emitter materials have subsequently been selected to produce pixels that achieve even higher apparent temperatures. Test results from pixels fabricated using the new material set will be presented and discussed. A 'scalable' Read In Integrated Circuit (RIIC) is also being developed under the same UHT program to drive the high temperature pixels. This RIIC will utilize through-silicon via (TSV) and Quilt Packaging (QP) technologies to allow seamless tiling of multiple chips to fabricate very large arrays, and thus overcome the yield limitations inherent in large-scale integrated circuits. Results of design verification testing of the completed RIIC will be presented and discussed.

  17. Ultra high frequency induction welding of powder metal compacts

    Directory of Open Access Journals (Sweden)

    Çavdar, Uǧur

    2014-06-01

    Full Text Available The application of the iron based Powder Metal (PM compacts in Ultra High Frequency Induction Welding (UHFIW were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined.Soldadura por inducción de ultra alta frecuencia de polvos de metal compactados. Se ha realizado un estudio de la aplicación de polvos de metal (PM de base hierro compactados por soldadura por inducción de ultra alta frecuencia (UHFIW. Estos polvos de metal compactados se utilizan para producir engranajes. Este estudio investiga los métodos de uni.n de los materiales de PM con UHFIW en su aplicación en la industria. La máxima tensión y la máxima deformación de los polvos de metal compactados soldados fueron determinadas por flexión en tres puntos y prueba de resistencia. Se determinó la microdureza y la microestructura de los polvos compactados por soldadura por inducción.

  18. Ultra-high vacuum compatible preparation chain for intermetallic compounds

    Science.gov (United States)

    Bauer, A.; Benka, G.; Regnat, A.; Franz, C.; Pfleiderer, C.

    2016-11-01

    We report the development of a versatile material preparation chain for intermetallic compounds, which focuses on the realization of a high-purity growth environment. The preparation chain comprises an argon glovebox, an inductively heated horizontal cold boat furnace, an arc melting furnace, an inductively heated rod casting furnace, an optically heated floating-zone furnace, a resistively heated annealing furnace, and an inductively heated annealing furnace. The cold boat furnace and the arc melting furnace may be loaded from the glovebox by means of a load-lock permitting to synthesize compounds starting with air-sensitive elements while handling the constituents exclusively in an inert gas atmosphere. All furnaces are all-metal sealed, bakeable, and may be pumped to ultra-high vacuum. We find that the latter represents an important prerequisite for handling compounds with high vapor pressure under high-purity argon atmosphere. We illustrate the operational aspects of the preparation chain in terms of the single-crystal growth of the heavy-fermion compound CeNi2Ge2.

  19. Ultra-high vacuum in superconducting accelerator rings

    Science.gov (United States)

    Bazanov, A. M.; Butenko, A. V.; Galimov, A. R.; Lugovnin, A. K.; Smirnov, A. V.

    2016-12-01

    Achieving the ultra-high vacuum (UHV) in the collider and booster of the NICA project is one of the main challenges when creating this device. It determines the need for a serious approach to this issue and conducting research in this direction. First, it is necessary to understand the effect of the various components of the vacuum systems on the degree of vacuum. It is also necessary to carry out studies of pumping devices for producing the required vacuum (10-9 Pa) in the beam chamber and choose the most optimal pumping scheme. At the same time, it is necessary to figure out how various operations are carried out with the vacuum chamber: preparation of vacuum surfaces, letting in the atmosphere, and warming the chamber after closing the influence on the degree of vacuum and the composition of the residual gas. The temperature may vary from room temperature to liquid helium temperature due to the difficulty of keeping the beam-chamber walls at a constant temperature, including the inner components. This complicates the processes taking place within it. Additional complexity arises due the heating of the chamber walls by various processes during the operation of the accelerator (for example, cycling the magnetic field).

  20. Generalized OFDM (GOFDM) for ultra-high-speed optical transmission.

    Science.gov (United States)

    Djordjevic, Ivan; Arabaci, Murat; Xu, Lei; Wang, Ting

    2011-03-28

    We propose a coded N-dimensional modulation scheme suitable for ultra-high-speed serial optical transport. The proposed scheme can be considered as a generalization of OFDM, and hence, we call it as generalized OFDM (GOFDM). In this scheme, the orthogonal subcarriers are used as basis functions and the signal constellation points are defined over this N-dimensional linear space. To facilitate implementation, we propose using N-dimensional pulse-amplitude modulation (ND-PAM) as the signal constellation diagram, which is obtained as the N-ary Cartesian product of one-dimensional PAM. In conventional OFDM, QAM/PSK signal constellation points are transmitted over orthogonal subcarriers and then they are multiplexed together in an OFDM stream. Individual subcarriers, therefore, carry N parallel QAM/PSK streams. In the proposed GOFDM scheme instead, an N-dimensional signal constellation point is transmitted over all N subcarriers simultaneously. When some of the subcarriers are severely affected by channel impairments, the constellation points carried by those subcarriers may be lost in the conventional OFDM. In comparison, under such conditions, the overall signal constellation point will face only small distortion in GOFDM and it can be recovered successfully using the information on the other high fidelity subcarriers. Furthermore, because the channel capacity is a logarithmic function of signal-to-noise ratio but a linear function of the number of dimensions, the spectral efficiency of optical transmission systems can be improved with GOFDM.

  1. Advanced Ultra-High Speed Motor for Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Impact Technologies LLC; University of Texas at Arlington

    2007-03-31

    Three (3) designs have been made for two sizes, 6.91 cm (2.72 inch) and 4.29 cm (1.69 inch) outer diameters, of a patented inverted configured Permanent Magnet Synchronous Machines (PMSM) electric motor specifically for drilling at ultra-high rotational speeds (10,000 rpm) and that can utilize advanced drilling methods. Benefits of these motors are stackable power sections, full control (speed and direction) of downhole motors, flow hydraulics independent of motor operation, application of advanced drilling methods (water jetting and abrasive slurry jetting), and the ability of signal/power electric wires through motor(s). Key features of the final designed motors are: fixed non-rotating shaft with stator coils attached; rotating housing with permanent magnet (PM) rotor attached; bit attached to rotating housing; internal channel(s) in a nonrotating shaft; electric components that are hydrostatically isolated from high internal pressure circulating fluids ('muds') by static metal to metal seals; liquid filled motor with smoothed features for minimized turbulence in the motor during operation; and new inverted coated metal-metal hydrodynamic bearings and seals. PMSM, Induction and Switched Reluctance Machines (SRM), all pulse modulated, were considered, but PMSM were determined to provide the highest power density for the shortest motors. Both radial and axial electric PMSM driven motors were designed with axial designs deemed more rugged for ultra-high speed, drilling applications. The 6.91 cm (2.72 inch) OD axial inverted motor can generate 4.18KW (5.61 Hp) power at 10,000 rpm with a 4 Nm (2.95 ft-lbs) of torque for every 30.48 cm (12 inches) of power section. The 6.91 cm (2.72 inch) OD radial inverted motor can generate 5.03 KW (6.74 Hp) with 4.8 Nm (3.54 ft-lb) torque at 10,000 rpm for every 30.48 cm (12 inches) of power section. The 4.29 cm (1.69 inch) OD radial inverted motor can generate 2.56 KW (3.43 Hp) power with 2.44 Nm (1.8 ft-lb) torque at

  2. Ultra-high field magnets for whole-body MRI

    Science.gov (United States)

    Warner, Rory

    2016-09-01

    For whole-body MRI, an ultra-high field (UHF) magnet is currently defined as a system operating at 7 T or above. Over 70 UHF magnets have been built, all with the same technical approach originally developed by Magnex Scientific Ltd. The preferred coil configuration is a compensated solenoid. In this case, the majority of the field is generated by a simple long solenoid that stretches the entire length of the magnet. Additional coils are wound on a separate former outside the main windings with the purpose of balancing the homogeneity. Most of the magnets currently in operation are passively shielded systems where the magnet is surrounded by a steel box of 200-870 tonnes of carbon steel. More recently actively shielded magnets have been built for operation at 7 T; in this case the stray field is controlled by with reverse turns wound on a separate former outside the primary coils. Protection against quench damage is much more complex with an actively shielded magnet design due to the requirement to prevent the stray field from increasing during a quench. In the case of the 7 T 900 magnet this controlled by combining some of the screening coils into each section of the protection circuit. Correction of the field variations caused by manufacturing tolerances and environmental effects are made with a combination of superconducting shims and passive shims. Modern UHF magnets operate in zero boil-off mode with the use of cryocoolers with cooling capacity at 4.2 K. Although there are no cryogen costs associated with normal operation UHF magnets require a significant volume (10 000-20 000 l) of liquid helium for the cool-down. Liquid helium is expensive therefore new methods of cool-down using high-power cryocoolers are being implemented to reduce the requirement.

  3. Ultra-high Density SNParray in Neuroblastoma Molecular Diagnostics

    Directory of Open Access Journals (Sweden)

    Inge M. Ambros

    2014-08-01

    Full Text Available Neuroblastoma serves as a paradigm for applying tumor genomic data for determining patient prognosis and thus for treatment allocation. MYCN status, i.e. amplified vs. non-amplified, was one of the very first biomarkers in oncology to discriminate aggressive from less aggressive or even favorable clinical courses of neuroblastoma. However, MYCN amplification is by far not the only genetic change associated with unfavorable clinical courses: so called segmental chromosomal aberrations, i.e. gains or losses of chromosomal fragments, can also indicate tumor aggressiveness. The clinical use of these genomic aberrations has, however, been hampered for many years by methodical and interpretational problems. Only after reaching worldwide consensus on markers, methodology, and data interpretation, information on SCAs has recently been implemented in clinical studies. Now, a number of collaborative studies within COG, GPOH and SIOPEN use genomic information to stratify therapy for patients with localized and metastatic disease. Recently, new types of DNA based aberrations influencing the clinical behavior of neuroblastomas have been described. Deletions or mutations of genes like ATRX and a phenomenon referred to as chromothripsis are all assumed to correlate with an unfavorable clinical behavior. However, these genomic aberrations need to be scrutinized in larger studies applying the most appropriate techniques. Single nucleotide polymorphism (SNP arrays have proven successful in deciphering genomic aberrations of cancer cells; these techniques, however, are usually not applied in the daily routine. Here, we present an ultra-high density (UHD SNParray technique which is, because of its high specificity and sensitivity and the combined copy number and allele information, highly appropriate for the genomic diagnosis of neuroblastoma and other malignancies.

  4. Photoionization study of doubly-excited helium at ultra-high resolution

    Energy Technology Data Exchange (ETDEWEB)

    Kaindl, G.; Schulz, K.; Domke, M. [Freie Universitaet Berlin (Germany)] [and others

    1997-04-01

    Ever since the pioneering work of Madden & Codling and Cooper, Fano & Prats on doubly-excited helium in the early sixties, this system may be considered as prototypical for the study of electron-electron correlations. More detailed insight into these states could be reached only much later, when improved theoretical calculations of the optically-excited {sup 1}P{sup 0} double-excitation states became available and sufficiently high energy resolution ({delta}E=4.0 meV) was achieved. This allowed a systematic investigation of the double-excitation resonances of He up to excitation energies close to the double-ionization threshold, I{sub infinity}=79.003 eV, which stimulated renewed theoretical interest into these correlated electron states. The authors report here on striking progress in energy resolution in this grazing-incidence photon-energy range of grating monochromators and its application to hitherto unobservable states of doubly-excited He. By monitoring an extremely narrow double-excitation resonance of He, with a theoretical lifetime width of less than or equal to 5 {mu}eV, a resolution of {delta}E=1.0 meV (FWHM) at 64.1 eV could be achieved. This ultra-high spectral resolution, combined with high photon flux, allowed the investigation of new Rydberg resonances below the N=3 ionization threshold, I{sub 3}, as well as a detailed comparison with ab-initio calculations.

  5. Design of a Multi-Channel Ultra-High Resolution Superconducting Gamma-Ray Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, S; Terracol, S F; Miyazaki, T; Drury, O B; Ali, Z A; Cunningham, M F; Niedermayr, T R; Barbee Jr., T W; Batteux, J D; Labov, S E

    2004-11-29

    Superconducting Gamma-ray microcalorimeters operated at temperatures around {approx}0.1 K offer an order of magnitude improvement in energy resolution over conventional high-purity Germanium spectrometers. The calorimeters consist of a {approx}1 mm{sup 3} superconducting or insulating absorber and a sensitive thermistor, which are weakly coupled to a cold bath. Gamma-ray capture increases the absorber temperature in proportion to the Gamma-ray energy, this is measured by the thermistor, and both subsequently cool back down to the base temperature through the weak link. We are developing ultra-high-resolution Gamma-ray spectrometers based on Sn absorbers and superconducting Mo/Cu multilayer thermistors for nuclear non-proliferation applications. They have achieved an energy resolution between 60 and 90 eV for Gamma-rays up to 100 keV. We also build two-stage adiabatic demagnetization refrigerators for user-friendly detector operation at 0.1 K. We present recent results on the performance of single pixel Gamma-ray spectrometers, and discuss the design of a large detector array for increased sensitivity.

  6. Ultra-high contrast frontend for high peak power fs-lasers at 1030 nm.

    Science.gov (United States)

    Liebetrau, Hartmut; Hornung, Marco; Seidel, Andreas; Hellwing, Marco; Kessler, Alexander; Keppler, Sebastian; Schorcht, Frank; Hein, Joachim; Kaluza, Malte C

    2014-10-01

    We present the results from a new frontend within a double-chirped pulse amplification architecture (DCPA) utilizing crossed-polarized wave generation (XPW) for generating ultra-high contrast, 150 μJ-level, femtosecond seed pulses at 1030 nm. These pulses are used in the high energy class diode-pumped laser system Polaris at the Helmholtz Institute in Jena. Within this frontend, laser pulses from a 75 MHz oscillator-pulse train are extracted at a repetition rate of 1 Hz, temporally stretched, amplified and then recompressed reaching a pulse energy of 2 mJ, a bandwidth of 12 nm and 112 fs pulse duration at a center wavelength of 1030 nm. These pulses are temporally filtered via XPW in a holographic-cut BaF₂ crystal, resulting in 150 μJ pulse energy with an efficiency of 13 %. Due to this non-linear filtering, the relative intensity of the amplified spontaneous emission preceding the main pulse is suppressed to 2×10⁻¹³. This is, to the best of our knowledge, the lowest value achieved in a high peak power laser system operating at 1030 nm center wavelength.

  7. Ultra High Temperature (UHT) SiC Fiber (Phase 2)

    Science.gov (United States)

    Dicarlo, James A.; Jacobson, Nathan S.; Lizcano, Maricela; Bhatt, Ramakrishna T.

    2015-01-01

    Silicon-carbide fiber-reinforced silicon-carbide ceramic matrix composites (SiCSiC CMC) are emerginglightweight re-usable structural materials not only for hot section components in gas turbine engines, but also for controlsurfaces and leading edges of reusable hypersonic vehicles as well as for nuclear propulsion and reactor components. Ithas been shown that when these CMC are employed in engine hot-section components, the higher the upper usetemperature (UUT) of the SiC fiber, the more performance benefits are accrued, such as higher operating temperatures,reduced component cooling air, reduced fuel consumption, and reduced emissions. The first generation of SiCSiC CMC with a temperature capability of 2200-2400F are on the verge of being introduced into the hot-section components ofcommercial and military gas turbine engines.Today the SiC fiber type currently recognized as the worlds best in terms ofthermo-mechanical performance is the Sylramic-iBN fiber. This fiber was previously developed by the PI at NASA GRC using patented processes to improve the high-cost commercial Sylramic fiber, which in turn was derived from anotherlow-cost low-performance commercial fiber. Although the Sylramic-iBN fiber shows state-of-the art creep and rupture resistance for use temperatures above 2550oF, NASA has shown by fundamental creep studies and model developmentthat its microstructure and creep resistance could theoretically be significantly improved to produce an Ultra HighTemperature (UHT) SiC fiber.This Phase II Seedling Fund effort has been focused on the key objective of effectively repeating the similar processes used for producing the Sylramic-iBN fiber using a design of experiments approach to first understand the cause of the less than optimum Sylramic-iBN microstructure and then attempting to develop processconditions that eliminate or minimize these key microstructural issues. In so doing, it is predicted that that theseadvanced process could result in an UHT Si

  8. High Baryon Densities in Heavy Ion Collisions at Energies Attainable at the Relativistic Heavy Ion Collider and the Large Hadron Collider

    CERN Document Server

    Li, Ming

    2016-01-01

    In very high energy collisions nuclei are practically tranparent to each other but produce very hot, nearly baryon-free, matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei at the highest energy attainable at the Relativistic Heavy Ion Collider, for example, we find baryon densities more than ten times that of atomic nuclei over a large volume.

  9. High baryon densities in heavy ion collisions at energies attainable at the BNL Relativistic Heavy-Ion Collider and the CERN Large Hadron Collider

    Science.gov (United States)

    Li, Ming; Kapusta, Joseph I.

    2017-01-01

    In very high-energy collisions nuclei are practically transparent to each other but produce very hot nearly baryon-free matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei at the highest energy attainable at the Relativistic Heavy-Ion Collider, for example, we find baryon densities more than ten times that of atomic nuclei over a large volume.

  10. Intervention in individuals at ultra high risk for psychosis: a review and future directions

    DEFF Research Database (Denmark)

    McGorry, Patrick D; Nelson, Barnaby; Amminger, G Paul;

    2009-01-01

    that neuroprotective agents, such as essential fatty acids, may be a suitable form of intervention for the ultra-high-risk phase of psychotic disorders, with a positive risk-benefit balance. Ethical aspects have become more salient given the recently observed declining transition rate in ultra-high-risk samples. We......OBJECTIVE: Over the last 15 years, a focus on early intervention in psychotic disorders has emerged. Initially, the early psychosis movement focused on timely recognition and phase-specific treatment of first-episode psychosis. However, early psychosis researchers suspected that pushing the point...... of intervention even further back to the prodromal phase of psychotic disorders may result in even better outcomes. This article reviews intervention research in the ultra-high-risk phase of psychotic disorders. DATA SOURCES: A literature search of intervention trials with ultra-high-risk cohorts published after...

  11. Intervention in individuals at ultra-high risk for psychosis: a review and future directions

    DEFF Research Database (Denmark)

    McGorry, Patrick D; Nelson, Barnaby; Amminger, G Paul;

    2009-01-01

    that neuroprotective agents, such as essential fatty acids, may be a suitable form of intervention for the ultra-high-risk phase of psychotic disorders, with a positive risk-benefit balance. Ethical aspects have become more salient given the recently observed declining transition rate in ultra-high-risk samples. We......OBJECTIVE: Over the last 15 years, a focus on early intervention in psychotic disorders has emerged. Initially, the early psychosis movement focused on timely recognition and phase-specific treatment of first-episode psychosis. However, early psychosis researchers suspected that pushing the point...... of intervention even further back to the prodromal phase of psychotic disorders may result in even better outcomes. This article reviews intervention research in the ultra-high-risk phase of psychotic disorders. DATA SOURCES: A literature search of intervention trials with ultra-high-risk cohorts published after...

  12. Press and Dryer Roll Surgaces and Web Transfer Systems for Ultra High Paper Maching Speeds

    Energy Technology Data Exchange (ETDEWEB)

    T. F. Patterson

    2004-03-15

    The objective of the project was to provide fundamental knowledge and diagnostic tools needed to design new technologies that will allow ultra high speed web transfer from press rolls and dryer cylinders.

  13. The Time Lens Concept Applied to Ultra-High-Speed OTDM Signal Processing

    DEFF Research Database (Denmark)

    Clausen, Anders; Palushani, Evarist; Mulvad, Hans Christian Hansen;

    2013-01-01

    This survey paper presents some of the applications where the versatile time-lens concept successfully can be applied to ultra-high-speed serial systems by offering expected needed functionalities for future optical communication networks....

  14. Premorbid adjustment in individuals at ultra-high risk for developing psychosis

    DEFF Research Database (Denmark)

    Dannevang, Anders; Randers, Lasse; Gondan, Matthias

    2016-01-01

    Objective: Deterioration in premorbid adjustment is related to ultra-high risk (UHR) individuals developing psychosis, but it has not been examined how UHR individuals’ development differs compared to healthy controls. This study investigates differences in premorbid adjustment between UHR...

  15. Seismic performance of steel reinforced ultra high-strength concrete composite frame joints

    Institute of Scientific and Technical Information of China (English)

    Yan Changwang; Jia Jinqing

    2010-01-01

    To investigate the seismic performance of a composite frame comprised of steel reinforced ultra high-strength concrete (SRUHSC) columns and steel reinforced concrete (SR.C) beams, six interior frame joint specimens were designed and tested under low cyclically lateral load. The effects of the axial load ratio and volumetric stirrup ratio were studied on the characteristics of the frame joint performance including crack pattern, failure mode, ductility, energy dissipation capacity, strength degradation and rigidity degradation. It was found that all joint specimens behaved in a ductile manner with flexural-shear failure in the joint core region while plastic hinges appeared at the beam ends. The ductility and energy absorption capacity of joints increased as the axial load ratio decreased and the volumetric stirrup ratio increased. The displacement ductility coefficient and equivalent damping coefficient of the joints fell between the corresponding coefficients of the steel reinforced concrete (SRC) frame joint and R.C frame joint. The axial load ratio and volumetric stirrup ratio have less influence on the strength degradation and more influence on the stiffness degradation. The stiffness of the joint degrades more significantly for a low volumetric stirrup ratio and high axial load ratio. The characteristics obtained from the SRUHSC composite frame joint specimens with better seismic performance may be a useful reference in future engineering applications.

  16. Seismic performance of steel reinforced ultra high-strength concrete composite frame joints

    Science.gov (United States)

    Yan, Changwang; Jia, Jinqing

    2010-09-01

    To investigate the seismic performance of a composite frame comprised of steel reinforced ultra high-strength concrete (SRUHSC) columns and steel reinforced concrete (SRC) beams, six interior frame joint specimens were designed and tested under low cyclically lateral load. The effects of the axial load ratio and volumetric stirrup ratio were studied on the characteristics of the frame joint performance including crack pattern, failure mode, ductility, energy dissipation capacity, strength degradation and rigidity degradation. It was found that all joint specimens behaved in a ductile manner with flexural-shear failure in the joint core region while plastic hinges appeared at the beam ends. The ductility and energy absorption capacity of joints increased as the axial load ratio decreased and the volumetric stirrup ratio increased. The displacement ductility coefficient and equivalent damping coefficient of the joints fell between the corresponding coefficients of the steel reinforced concrete (SRC) frame joint and RC frame joint. The axial load ratio and volumetric stirrup ratio have less influence on the strength degradation and more influence on the stiffness degradation. The stiffness of the joint degrades more significantly for a low volumetric stirrup ratio and high axial load ratio. The characteristics obtained from the SRUHSC composite frame joint specimens with better seismic performance may be a useful reference in future engineering applications.

  17. Direct tension and fracture resistance curves of ultra high performance marine composite materials

    Institute of Scientific and Technical Information of China (English)

    WU Xiang-guo; HAN Sang-mook

    2008-01-01

    Fracture behavior is one of the most important, yet still little understood properties of ultra-high performance cementitious composites (UHPCC), a new marine structural engineering material.Research on the fracture and direct tension behavior of UHPCC was carried out. The constitution law of UHPCC was divided into three phases: pre-partial debonding, partial debonding, and pullout phases. A direct tension constitution law was constructed based on the proposed fiber reinforcing parameter as a function of fiber volume fraction, fiber diameter and length, and fiber bonding strength. With the definition of linear crack shape, the energy release rate of UHPCC was derived and the R-curve equation was calculated from this. Loading tests of UHPCC using a three-point bending beam with an initial notch were carried out. The predictions from the proposed R-curve were in good agreement with the test results,indicating that the proposed R-curve accurately describes the fracture resistance of UHPCC. Introductionof a fiber reinforcement parameter bridges the fracture property R-curve and micro-composites mechanics parameters together. This has laid the foundation for further research into fracture properties based on micro-mechanics. The proposed tension constitution law and R-curve can be references for future UHPCC fracture evaluation.

  18. Sustainability Assessment of Precast Ultra-High Performance Fiber Reinforced Concrete (UHPFRC Cantilever Retaining Walls

    Directory of Open Access Journals (Sweden)

    Behzad Nematollahi

    2014-05-01

    Full Text Available This study evaluates the environmental impacts of a newly designed precast Ultra-High Performance Fiber Reinforced Concrete (UHPFRC cantilever retaining wall as a sustainable alternative approach compared with the conventional precast Reinforced Concrete (RC cantilever retaining wall. Nowadays, according to the shocking reports of many researchers worldwide global warming is one of the most devastating problems of human being. To date, lots of research has been undertaken in the concrete industry to tackle this issue through reducing the environmental footprints of our structural designs. In this regard, UHPFRC technology offers substantial benefits through efficient use of materials as well as optimization of the structural designs resulting less CO2 emissions, Embodied Energy (EE and Global Warming Potential (GWP. UHPFRC as a sustainable construction material is mostly appropriate for the use in the fabrication of precast members such as precast concrete cantilever retaining walls. This study demonstrates the overview of the designed precast concrete cantilever retaining wall manufactured from UHPFRC and its Environmental Impact Calculations (EIC versus the conventional precast RC cantilever retaining walls. Based on the EIC results, the precast UHPFRC cantilever retaining walls are generally more environmentally sustainable than those built of the conventional RC with respect to the reduction of CO2 emissions, EE and GWP. In summary, the precast UHPFRC cantilever retaining wall proposed in this study is an alternative sustainable solution compared with the conventional precast RC cantilever retaining wall which can be used in many civil engineering projects.

  19. Isoflavone Profiles and Kinetic Changes during Ultra-High Temperature Processing of Soymilk.

    Science.gov (United States)

    Zhang, Yan; Chang, Sam K C

    2016-03-01

    Isoflavone profile is greatly affected by heating process. However, kinetic analyses of isoflavone conversion and degradation using a continuous industry processing method have never been characterized. In this study, Proto soybean was soaked and blanched at 80 °C for 2 min and then processed into soymilk, which underwent UHT (ultra-high temperature) at 135 to 150 °C for 10 to 50 s with a pilot plant-scale Microthermics processor. The isoflavone profile was determined at different time/temperature combinations. The results showed that all isoflavone forms exhibited distinct changing patterns over time. In the soymilk under UHT conditions, the degradation (disappearance) of malonyldaizin and malonylgenistin exhibited first-order kinetics with activation energies of 59 and 84 kj/mole, respectively. At all UHT temperatures, malonylgenistin showed higher rate constants than malonyldaidzin. However, malonylglycitin changed irregularly under these UHT temperatures. The increase of genistin, daidzin, glycitein and acetlydaidzin during heating demonstrated zero-order kinetics and the rate constants increased with temperature except for the conditions of 145 to 150 °C for 50 s. Overall, genistein series exhibited higher stability than daidzein series. Under all UHT conditions, total isoflavone decreased from 12% to 24%.

  20. Nanocomposites of TiO₂/cyanoethylated cellulose with ultra high dielectric constants.

    Science.gov (United States)

    Madusanka, Nadeesh; Shivareddy, Sai G; Hiralal, Pritesh; Eddleston, Mark D; Choi, Youngjin; Oliver, Rachel A; Amaratunga, Gehan A J

    2016-05-13

    A novel dielectric nanocomposite containing a high permittivity polymer, cyanoethylated cellulose (CRS) and TiO2 nanoparticles was successfully prepared with different weight percentages (10%, 20% and 30%) of TiO2. The intermolecular interactions and morphology within the polymer nanocomposites were analysed. TiO2/CRS nanofilms on SiO2/Si wafers were used to form metal-insulator-metal type capacitors. Capacitances and loss factors in the frequency range of 1 kHz-1 MHz were measured. At 1 kHz CRS-TiO2 nanocomposites exhibited ultra high dielectric constants of 118, 176 and 207 for nanocomposites with 10%, 20% and 30% weight of TiO2 respectively, significantly higher than reported values of pure CRS (21), TiO2 (41) and other dielectric polymer-TiO2 nanocomposite films. Furthermore, all three CRS-TiO2 nanocomposites show a loss factor dielectric constant hybrids using nanoscale inorganic dielectrics dispersed in a high permittivity polymer suitable for energy management applications is reported.

  1. Nanocomposites of TiO2/cyanoethylated cellulose with ultra high dielectric constants

    Science.gov (United States)

    Madusanka, Nadeesh; Shivareddy, Sai G.; Hiralal, Pritesh; Eddleston, Mark D.; Choi, Youngjin; Oliver, Rachel A.; Amaratunga, Gehan A. J.

    2016-05-01

    A novel dielectric nanocomposite containing a high permittivity polymer, cyanoethylated cellulose (CRS) and TiO2 nanoparticles was successfully prepared with different weight percentages (10%, 20% and 30%) of TiO2. The intermolecular interactions and morphology within the polymer nanocomposites were analysed. TiO2/CRS nanofilms on SiO2/Si wafers were used to form metal-insulator-metal type capacitors. Capacitances and loss factors in the frequency range of 1 kHz-1 MHz were measured. At 1 kHz CRS-TiO2 nanocomposites exhibited ultra high dielectric constants of 118, 176 and 207 for nanocomposites with 10%, 20% and 30% weight of TiO2 respectively, significantly higher than reported values of pure CRS (21), TiO2 (41) and other dielectric polymer-TiO2 nanocomposite films. Furthermore, all three CRS-TiO2 nanocomposites show a loss factor dielectric constant hybrids using nanoscale inorganic dielectrics dispersed in a high permittivity polymer suitable for energy management applications is reported.

  2. Ultra high molecular weight polyethylene as a base material for shielding cosmic radiation in aerospace applications

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Marlon A., E-mail: marlon@ieav.cta.br [Instituto de Estudos Avancados (IEAv), Sao Jose dos Campos, SP (Brazil). Divisao de Fisica Aplicada; Goncalez, Odair L. [Instituto Tecnologico de Aeronautica (PG/CTE/ITA), Sao Jose dos Campos, SP (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnologias Espaciais

    2013-07-01

    Materials with high content of hydrogen have good properties of shielding against the effects of cosmic rays (CR) because are less effective than materials with high nuclear masses in the generation of secondary radiation. Beside the Aluminum, Polyethylene has been used as a reference and as a base material for composites applied in structures and in shielding of ionizing radiation for aerospace applications. Ultra high molecular weight polyethylene (UHMWPE), pure and doped 10% by mass with cadmium chloride, had its shielding properties for CR evaluated in this paper. Methodology used was based in conventional radioactive sources employed on simple geometries experiments and then computational simulation for isotropic fluxes of cosmic-ray high energy particles. Transmission experiments were performed with a3.7GBq (100 mCi){sup 241}Am-Be neutron source and a set of conventional calibration gamma radiation sources. Samples were characterized according to their gamma total attenuation coefficients from 59 to 1,408 keV, dose deposition curve for {sup 60}Co gamma-rays, fast neutron transmission coefficient, generation and self-absorption of thermal neutrons as well as their generation of internal cascades of secondary electrons and gamma-rays by nuclear interactions of fast neutrons with shielding material. Main effects of the additive in the polyethylene base were the most effective removal of gamma radiation and of secondary electrons with energies below 200 keV, the reduction of the albedo as well as the thermal neutrons transmission. Dose reduction due to primary CR were not significant, since the largest contribution to the doses due to high energy ionizing particles transmitted and, also, due to secondary radiation with energy above 1 MeV produced in shielding. (author)

  3. On LiF:Mg,Cu,P and LiF:Mg,Ti phosphors high & ultra-high dose features

    CERN Document Server

    Obryk, Barbara; de Barros, Vinicius S; Guzzo, Pedro L; Bilski, Paweł

    2013-01-01

    LiF:Mg,Ti and LiF:Mg,Cu,P are well known thermoluminescence (TL) dosimetry materials since many years. A few years ago their properties seemed well known and it was widely believed that they are not suitable for the measurement of doses above the saturation level of the TL signal, which for both materials occur at about 1 kGy. The high-dose high-temperature TL emission of LiF:Mg,Cu,P observed at the IFJ in 2006, which above 30 kGy takes the form of the so-called TL peak B, opened the way to use this material for measuring the dose in the high and ultra-high range, in particular for the monitoring of ionizing radiation around the essential electronic elements of high-energy accelerators, also fission and fusion facilities, as well as for emergency dosimetry. This discovery initiated studies of high and ultra-high dose characteristics of both of these phosphors, which turned out to be significantly different in many aspects. These studies not only strive to refine the method for measuring high doses based on th...

  4. SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Alan Black; Arnis Judzis

    2004-10-01

    The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high (greater than 10,000 rpm) rotational speeds. The work includes a feasibility of concept research effort aimed at development and test results that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with rigs having a smaller footprint to be more mobile. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration rock cutting with substantially lower inputs of energy and loads. The project draws on TerraTek results submitted to NASA's ''Drilling on Mars'' program. The objective of that program was to demonstrate miniaturization of a robust and mobile drilling system that expends small amounts of energy. TerraTek successfully tested ultrahigh speed ({approx}40,000 rpm) small kerf diamond coring. Adaptation to the oilfield will require innovative bit designs for full hole drilling or continuous coring and the eventual development of downhole ultra-high speed drives. For domestic operations involving hard rock and deep oil and gas plays, improvements in penetration rates is an opportunity to reduce well costs and make viable certain field developments. An estimate of North American hard rock drilling costs is in excess of $1,200 MM. Thus potential savings of $200 MM to $600 MM are possible if drilling rates are doubled [assuming bit life is reasonable]. The net result for operators is improved profit margin as well as an improved position on reserves. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology

  5. SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Alan Black; Arnis Judzis

    2004-10-01

    The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high (greater than 10,000 rpm) rotational speeds. The work includes a feasibility of concept research effort aimed at development and test results that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with rigs having a smaller footprint to be more mobile. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration rock cutting with substantially lower inputs of energy and loads. The project draws on TerraTek results submitted to NASA's ''Drilling on Mars'' program. The objective of that program was to demonstrate miniaturization of a robust and mobile drilling system that expends small amounts of energy. TerraTek successfully tested ultrahigh speed ({approx}40,000 rpm) small kerf diamond coring. Adaptation to the oilfield will require innovative bit designs for full hole drilling or continuous coring and the eventual development of downhole ultra-high speed drives. For domestic operations involving hard rock and deep oil and gas plays, improvements in penetration rates is an opportunity to reduce well costs and make viable certain field developments. An estimate of North American hard rock drilling costs is in excess of $1,200 MM. Thus potential savings of $200 MM to $600 MM are possible if drilling rates are doubled [assuming bit life is reasonable]. The net result for operators is improved profit margin as well as an improved position on reserves. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology

  6. Ultra-High Intensity Magnetic Field Generation in Dense Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Fisch, Nathaniel J

    2014-01-08

    I. Grant Objective The main objective of this grant proposal was to explore the efficient generation of intense currents. Whereasthefficient generation of electric current in low-­energy-­density plasma has occupied the attention of the magnetic fusion community for several decades, scant attention has been paid to carrying over to high-­energy-­density plasma the ideas for steady-­state current drive developed for low-­energy-­density plasma, or, for that matter, to inventing new methodologies for generating electric current in high-­energy-­density plasma. What we proposed to do was to identify new mechanisms to accomplish current generation, and to assess the operation, physics, and engineering basis of new forms of current drive in regimes appropriate for new fusion concepts.

  7. Is Ultra-High Reynolds Number Necessary for Comprehensive Log Scaling in a Turbulent Boundary Layer?

    CERN Document Server

    Dixit, Shivsai Ajit

    2015-01-01

    Experiments in an extraordinary turbulent boundary layer called the sink flow, displaying a perfect streamwise invariance, show a wide extent of logarithmic scaling for moments of streamwise velocity up to order 12, even at moderate Reynolds numbers. This is in striking contrast to canonical constant-pressure turbulent boundary layers that show such comprehensive log scaling only at ultra-high Reynolds numbers. This suggests that for comprehensive log scaling, ultra-high-Reynolds-number is not a necessary condition; while specific details of the sink flow are special, the relevance to general turbulent boundary layers is that the sink flow underscores the importance of the streamwise invariance condition that needs to be met in a general flow for obtaining log scaling. Indeed, a simple theory shows that, for log scaling in the inertial sublayer, the invariance of dimensionless mean velocity and higher-order moments along a mean streamline is a necessary and sufficient condition. Ultra-high Reynolds number pri...

  8. Laser beam welding of new ultra-high strength and supra-ductile steels

    Science.gov (United States)

    Dahmen, Martin

    2015-03-01

    Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting the weld microstructure the Q+P and the QT steels require weld heat treatment. The HSD steel is weldable without. Due to their applications the ultra-high strength steels are welded in as-rolled and strengthened condition. Also the reaction of the weld on hot stamping is reflected for the martensitic grades. The supra-ductile steels are welded as solution annealed and work hardened by 50%. The results show the general suitability for laser beam welding.

  9. Field Evaluation of Ultra-High Pressure Water Systems for Runway Rubber Removal

    Science.gov (United States)

    2014-04-01

    ER D C/ G SL T R- 14 -1 1 Field Evaluation of Ultra-High Pressure Water Systems for Runway Rubber Removal G eo te ch ni ca l a nd S tr...Field Evaluation of Ultra-High Pressure Water Systems for Runway Rubber Removal Aaron B. Pullen Applied Research Associates, Inc. 421 Oak Avenue...Engineer Center Tyndall Air Force Base, FL 32403-5319 ERDC/GSL TR-14-11 ii Abstract Runway rubber removal is a maintenance function employed to

  10. Design and Implementation of Wideband Exciter for an Ultra-high Resolution Airborne SAR System

    Directory of Open Access Journals (Sweden)

    Jia Ying-xin

    2013-03-01

    Full Text Available According to an ultra-high resolution airborne SAR system with better than 0.1 m resolution, a wideband Linear Frequency Modulated (LFM pulse compression exciter with 14.8 GHz carrier and 3.2 GHz bandwidth is designed and implemented. The selection of signal generation scheme and some key technique points for wideband LFM waveform is presented in detail. Then, an acute test and analysis of the LFM signal is performed. The final airborne experiments demonstrate the validity of the LFM source which is one of the subsystems in an ultra-high resolution airborne SAR system.

  11. A DFB Fiber Laser Sensor System with Ultra-High Resolution and Its Noise Analysis

    Institute of Scientific and Technical Information of China (English)

    Hao Xiao; Fang Li; Jun He; Yu-Liang Liu

    2008-01-01

    A distributed feedback fiber laser (DFB FL) sensor system with ultra-high resolution is described. The sensor is made by writing distributed feedback structures into a high gain active fiber, and the system employs an unbalanced Michelson interferometer to translate laser wavelength shifts induced by weak measurands into phase shifts. A digital phase generated carrier demodulation scheme is introduced to achieve ultra-high resolution interrogation. A detailed noise analysis of the system is presented, and it is shown that the system resolution is limited by the frequency noise of the DFB FL.

  12. Novel Routes for Sintering of Ultra-high Temperature Ceramics and their Properties

    Science.gov (United States)

    2014-10-31

    AFRL-AFOSR-UK-TR-2015-0017 Novel Routes for Sintering of Ultra-high Temperature Ceramics and their Properties Oleg...Ultra-high Temperature Ceramics and their Properties  5a. CONTRACT NUMBER STCU P-511 5b. GRANT NUMBER STCU 11-8002 5c. PROGRAM ELEMENT NUMBER...it defines the elevated diffusion activity at sintering. 2. In the ZrB2-SiC-5% Cr3C2 system, hot pressing allows to obtain porous free ceramics at

  13. All-optical ultra-high-speed OFDM to Nyquist-WDM conversion

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen

    2015-01-01

    We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER <10−9 performance for all channels.......We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER

  14. Ultra high temperature ceramics (UHTCs) for severe environment

    OpenAIRE

    Sciti, Diletta; Bellosi, Alida; Guicciardi, Stefano; Monteverde, Frederic; Medri, Valentina; Silvestroni, Laura

    2010-01-01

    Borides and carbides of Hf, Ta, Zr and related composites are materials of great interest. These groups of ceramics, combining outstanding levels of robustness and refractoriness, are currently widely recognized as the unique materials for harsh service environnients, especially for aerospace, rocket propulsion and energy applications

  15. Development of the ultra high efficiency thermal power generation facility

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Toshihiro

    2010-09-15

    In order to prevent global warming, attention is focused on nuclear power generation and renewable energy such as wind and solar power generation. The electric power suppliers of Japan are aiming to increase the amount of nuclear and non-fossil fuel power generation over 50% of the total power generation by 2020. But this means that the remaining half will still be of thermal power generation using fossil fuel and will still play an important role. Under such circumstances, further efficiency improvement of the thermal power generation and its aggressive implementation is ongoing in Japan.

  16. Design and performance of a soft-x-ray interferometer for ultra-high-resolution fourier transform spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Moler, E.J.; Hussain, Z.; Duarte, R.M.; Howells, M.R. [Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    A Fourier Transform Soft X-ray spectrometer (FT-SX) has been designed and is under construction for the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory as a branch of beamline 9.3.2. The spectrometer is a novel soft x-ray interferometer designed for ultra-high resolution (theoretical resolving power E/{delta}E{approximately}10{sup 6}) spectroscopy in the photon energy region of 60-120 eV. This instrument is expected to provide experimental results which sensitively test models of correlated electron processes in atomic and molecular physics. The design criteria and consequent technical challenges posed by the short wavelengths of x-rays and desired resolving power are discussed. The fundamental and practical aspects of soft x-ray interferometry are also explored.

  17. Characterization of Impact Damage in Ultra-High Performance Concrete Using Spatially Correlated Nanoindentation/SEM/EDX

    Science.gov (United States)

    Moser, R. D.; Allison, P. G.; Chandler, M. Q.

    2013-12-01

    Little work has been done to study the fundamental material behaviors and failure mechanisms of cement-based materials including ordinary Portland cement concrete and ultra-high performance concretes (UHPCs) under high strain impact and penetration loads at lower length scales. These high strain rate loadings have many possible effects on UHPCs at the microscale and nanoscale, including alterations in the hydration state and bonding present in phases such as calcium silicate hydrate, in addition to fracture and debonding. In this work, the possible chemical and physical changes in UHPCs subjected to high strain rate impact and penetration loads were investigated using a novel technique wherein nanoindentation measurements were spatially correlated with images using scanning electron microscopy and chemical composition using energy dispersive x-ray microanalysis. Results indicate that impact degrades both the elastic modulus and indentation hardness of UHPCs, and in particular hydrated phases, with damage likely occurring due to microfracturing and debonding.

  18. High-speed spinning of ultra-high molecular weight polyethylene fibres

    NARCIS (Netherlands)

    Roukema, Mees

    1991-01-01

    This thesis deals with the spinning of ultra-high molecular weight polyethylene ( UHMWPE ) fibres at high speeds, and the effects of the spinning parameters on the fibre properties. Polyethylene fibres with strengths up to 7.2 GPa can be produced in a gel-spinning and hot-drawing procedure. In this

  19. Multi-modal ultra-high resolution structural 7-Tesla MRI data repository

    NARCIS (Netherlands)

    B.U. Forstmann; M.C. Keuken; A Schafer; P.-L. Bazin; A. Alkemade; R. Turner

    2014-01-01

    Structural brain data is key for the understanding of brain function and networks, i.e., connectomics. Here we present data sets available from the ‘atlasing of the basal ganglia (ATAG)’ project, which provides ultra-high resolution 7 Tesla (T) magnetic resonance imaging (MRI) scans from young, midd

  20. Childhood trauma and clinical outcome in patients at ultra-high risk of transition to psychosis

    NARCIS (Netherlands)

    Kraan, Tamar; van Dam, Daniella S.; Velthorst, Eva; de Ruigh, Esther L.; Nieman, Dorien H.; Durston, Sarah; Schothorst, Patricia; van der Gaag, Mark; de Haan, Lieuwe

    2015-01-01

    Background: Although transition rates in 'ultra-high risk' (UHR) for psychosis samples are declining,many young individuals at UHR still experience attenuated positive symptoms and impaired functioning at follow-up. The present study examined the association between a history of childhood trauma and

  1. Wear behaviour of discontinuous aramid fibre reinforced ultra-high molecular weight polyethylene

    NARCIS (Netherlands)

    Hofste, JM; Smit, HHG; Pennings, AJ

    1996-01-01

    The wear of Ultra-High Molecular Weight Polyethylene has generated new concern regarding the long-term clinical performance of total joint replacements. To extend the lifetime of artificial joints, it is necessary to decrease tt-le wear rate of UHMWPE. One possible solution is the incorporation of a

  2. Short aramid-fiber reinforced ultra-high molecular weight polyethylene

    NARCIS (Netherlands)

    Hofste, JM; Bergmans, KJR; deBoer, J; Wevers, R; Pennings, AJ

    1996-01-01

    Ultra-High Molecular Weight Polyethylene (UHMWPE) is frequently used in artificial joints because of its high wear resistance. To extend the lifetime of these joints even further, it is necessary to decrease the wear rate. The wear rate may be decreased by blending UHMWPE with short aramid fibers. O

  3. Deformation and degradation of polymers in ultra-high-pressure liquid chromatography

    NARCIS (Netherlands)

    Uliyanchenko, E.; van der Wal, S.; Schoenmakers, P.J.

    2011-01-01

    Ultra-high-pressure liquid chromatography (UHPLC) using columns packed with sub-2 μm particles has great potential for separations of many types of complex samples, including polymers. However, the application of UHPLC for the analysis of polymers meets some fundamental obstacles. Small particles an

  4. Brain development in adolescents at ultra-high risk for psychosis : Longitudinal changes related to resilience

    NARCIS (Netherlands)

    de Wit, Sanne; Wierenga, Lara M; Oranje, Bob; Ziermans, Tim B; Schothorst, Patricia F; van Engeland, Herman; Kahn, René S; Durston, Sarah

    2016-01-01

    BACKGROUND: The main focus of studies of individuals at ultra-high risk for psychosis (UHR) has been on identifying brain changes in those individuals who will develop psychosis. However, longitudinal studies have shown that up to half of UHR individuals are resilient, with symptomatic remission and

  5. Connections in Precast Buildings using Ultra High-Strength Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Hansen, Lars Pilegaard

    1995-01-01

    Ultra high-strength concrete adds new dimensions to the design of concrete structures. It is a brittle material but introducing fibres into the matrix changes the material into a highly ductile material. Furthermore, the fibre reinforcement increases the anchorage of traditional reinforcement bars...

  6. 78 FR 70567 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final...

    Science.gov (United States)

    2013-11-26

    ...] [FR Doc No: 2013-28337] DEPARTMENT OF HOMELAND SECURITY Coast Guard [Docket No. USCG-2009-0166... Programmatic Environmental Assessment (PEA) for the Nationwide Use of High Frequency (HF) and Ultra High..., recreational boating, or other maritime activities. The use of HF (50 to 999 kHz) and UHF (1,000 kHz and...

  7. Solutions for ultra-high speed optical wavelength conversion and clock recovery

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen

    2006-01-01

    This paper reports on our recent advances in ultra-fast optical communications relying on ultra-short pulses densely stacked in ultra-high bit rate serial data signals at a single wavelength. The paper describes details in solutions for the network functionalities of wavelength conversion and clock...... recovery at bit rates up to 320 Gb/s...

  8. Multiphysics Modeling of a Novel Photoelastic Modulator for Ultra-High Performance FT Spectrometry

    Science.gov (United States)

    2008-12-01

    1 MULTIPHYSICS MODELING OF A NOVEL PHOTOELASTIC MODULATOR FOR ULTRA-HIGH PERFORMANCE FT SPECTROMETRY Tudor N. Buican* Semiotic Engineering...NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Semiotic

  9. Ultra-high-speed optical signal processing of serial data signals

    DEFF Research Database (Denmark)

    Clausen, Anders; Mulvad, Hans Christian Hansen; Palushani, Evarist;

    2012-01-01

    To ensure that ultra high-speed serial data signals can be utilised in future optical communication networks, it is indispensable to have all-optical signal processing elements at our disposal. In this paper, the most recent advances in our use of non-linear materials incorporated in different...

  10. Ultra-High Temperature Metallic Seal/Energizer Development for Aero Propulsion and Gas Turbine Applications

    Science.gov (United States)

    Cornett, Ken; Newman, Jesse; Datta, Amit

    2009-01-01

    The industry is requiring seals to operate at higher and higher temperatures. Traditional static seal designs and materials experience stress relaxation, losing their ability to maintain contact with moving flanges. Ultra High Temperature seal development program is a multiphase program with incremental increases in seal operating temperatures.

  11. Toward nanofluids of ultra-high thermal conductivity.

    Science.gov (United States)

    Wang, Liqiu; Fan, Jing

    2011-02-18

    The assessment of proposed origins for thermal conductivity enhancement in nanofluids signifies the importance of particle morphology and coupled transport in determining nanofluid heat conduction and thermal conductivity. The success of developing nanofluids of superior conductivity depends thus very much on our understanding and manipulation of the morphology and the coupled transport. Nanofluids with conductivity of upper Hashin-Shtrikman (H-S) bound can be obtained by manipulating particles into an interconnected configuration that disperses the base fluid and thus significantly enhancing the particle-fluid interfacial energy transport. Nanofluids with conductivity higher than the upper H-S bound could also be developed by manipulating the coupled transport among various transport processes, and thus the nature of heat conduction in nanofluids. While the direct contributions of ordered liquid layer and particle Brownian motion to the nanofluid conductivity are negligible, their indirect effects can be significant via their influence on the particle morphology and/or the coupled transport.

  12. Ultra-High-Performance Concrete And Advanced Manufacturing Methods For Modular Construction

    Energy Technology Data Exchange (ETDEWEB)

    Sawab, Jamshaid [Univ. of Houston, Houston, TX (United States); Lim, Ing [Univ. of Houston, Houston, TX (United States); Mo, Yi-Lung [Univ. of Houston, Houston, TX (United States); Li, Mo [Univ. of Houston, Houston, TX (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Guimaraes, Maria [Electric Power Research Inst. (EPRI), Knoxville, TN (United States)

    2016-04-13

    Small modular reactors (SMR) allow for less onsite construction, increase nuclear material security, and provide a flexible and cost-effective energy alternative. SMR can be factory-built as modular components, and shipped to desired locations for fast assembly. This project successfully developed a new class of ultra-high performance concrete (UHPC), which features a compressive strength greater than 22 ksi (150 MPa) without special treatment and self-consolidating characteristics desired for SMR modular construction. With an ultra-high strength and dense microstructure, it will facilitate rapid construction of steel plate-concrete (SC) beams and walls with thinner and lighter modules, and can withstand harsh environments and mechanical loads anticipated during the service life of nuclear power plants. In addition, the self-consolidating characteristics are crucial for the fast construction and assembly of SC modules with reduced labor costs and improved quality. Following the UHPC material development, the capacity of producing self-consolidating UHPC in mass quantities was investigated and compared to accepted self-consolidating concrete standards. With slightly adjusted mixing procedure using large-scale gravity-based mixers (compared with small-scale force-based mixer), the self-consolidating UHPC has been successfully processed at six cubic yards; the product met both minimum compressive strength requirements and self-consolidating concrete standards. Steel plate-UHPC beams (15 ft. long, 12 in. wide and 16 in. deep) and wall panels (40 in. X 40 in. X 3 in.) were then constructed using the self-consolidating UHPC without any external vibration. Quality control guidelines for producing UHPC in large scale were developed. When the concrete is replaced by UHPC in a steel plate concrete (SC) beam, it is critical to evaluate its structural behavior with both flexure and shear-governed failure modes. In recent years, SC has been widely used for buildings and nuclear

  13. Advanced Production Surface Preparation Technology Development for Ultra-High Pressure Diesel Injection

    Energy Technology Data Exchange (ETDEWEB)

    Grant, Marion B.

    2012-04-30

    In 2007, An Ultra High Injection Pressure (UHIP) fueling method has been demonstrated by Caterpillar Fuel Systems - Product Development, demonstrating ability to deliver U.S. Environment Protection Agency (EPA) Tier 4 Final diesel engine emission performance with greatly reduced emissions handling components on the engine, such as without NOx reduction after-treatment and with only a through-flow 50% effective diesel particulate trap (DPT). They have shown this capability using multiple multi-cylinder engine tests of an Ultra High Pressure Common Rail (UHPCR) fuel system with higher than traditional levels of CEGR and an advanced injector nozzle design. The system delivered better atomization of the fuel, for more complete burn, to greatly reduce diesel particulates, while CEGR or high efficiency NOx reduction after-treatment handles the NOx. With the reduced back pressure of a traditional DPT, and with the more complete fuel burn, the system reduced levels of fuel consumption by 2.4% for similar delivery of torque and horsepower over the best Tier 4 Interim levels of fuel consumption in the diesel power industry. The challenge is to manufacture the components in high-volume production that can withstand the required higher pressure injection. Production processes must be developed to increase the toughness of the injector steel to withstand the UHIP pulsations and generate near perfect form and finish in the sub-millimeter size geometries within the injector. This project resulted in two developments in 2011. The first development was a process and a machine specification by which a high target of compressive residual stress (CRS) can be consistently imparted to key surfaces of the fuel system to increase the toughness of the steel, and a demonstration of the feasibility of further refinement of the process for use in volume production. The second development was the demonstration of the feasibility of a process for imparting near perfect, durable geometry to

  14. Chemical fingerprint of Ganmaoling granule by double-wavelength ultra high performance liquid chromatography and ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Lou, Qiong; Ye, Xiaolan; Zhou, Yingyi; Li, Hua; Song, Fenyun

    2015-06-01

    A method incorporating double-wavelength ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry was developed for the investigation of the chemical fingerprint of Ganmaoling granule. The chromatographic separations were performed on an ACQUITY UPLC HSS C18 column (2.1 × 50 mm, 1.8 μm) at 30°C using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. A total of 11 chemical constituents of Ganmaoling granule were identified from their molecular weight, UV spectra, tandem mass spectrometry data, and retention behavior by comparing the results with those of the reference standards or literature. And 25 peaks were selected as the common peaks for fingerprint analysis to evaluate the similarities among 25 batches of Ganmaoling granule. The results of principal component analysis and orthogonal projection to latent structures discriminant analysis showed that the important chemical markers that could distinguish the different batches were revealed as 4,5-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4-O-caffeoylquinic acid. This is the first report of the ultra high performance liquid chromatography chemical fingerprint and component identification of Ganmaoling granule, which could lay a foundation for further studies of Ganmaoling granule.

  15. Sterilization of liquid foods by pulsed electric fields – an innovative ultra-high temperature process

    Directory of Open Access Journals (Sweden)

    Kai eReineke

    2015-05-01

    Full Text Available The intention of this study was to investigate the inactivation of endospores by a combined thermal and pulsed electric field (PEF treatment. Therefore, self-cultivated spores of Bacillus subtilis and commercial Geobacillus stearothermophilus spores with certified heat resistance were utilized. Spores of both strains were suspended in saline water (5.3 mS cm-1, skim milk (0.3% fat; 5.3 mS cm-1 and fresh prepared carrot juice (7.73 mS cm-1. The combination of moderate preheating (70-90 °C and an insulated PEF-chamber, combined with a holding tube (65 cm and a heat exchanger for cooling, enabled a rapid heat up to 105-140 °C (measured above the PEF chamber within 92.2-368.9 µs. To compare the PEF process with a pure thermal inactivation, each spore suspension was heat treated in thin glass capillaries and D-values from 90 to 130°C and its corresponding z-values were calculated. For a comparison of the inactivation data, F-values for the temperature fields of both processes were calculated by using Comsol Multiphysics combined with a Matlab routine.A preheating of saline water to 70 °C with a flow rate of 5 l h-1, a frequency of 150 Hz and an energy input of 226.5 kJ kg-1, resulted in a measured outlet temperature of 117 °C and a 4.67 log10 inactivation of Bacillus subtilis. The thermal process with identical F-value caused only a 3.71 log10 inactivation. This synergism of moderate preheating and PEF was even more pronounced for Geobacillus stearothermophilus spores in saline water. A preheating to 95 °C and an energy input of 144 kJ kg-1 resulted in an outlet temperature of 126 °C and a 3.28 log10 inactivation, whereas nearly no inactivation (0.2 log10 was achieved during the thermal treatment.Hence, the PEF technology was evaluated as an alternative ultra-high temperature process. However, for an industrial scale application of this process for sterilization, optimization of the treatment chamber design is needed to reduce the occurring

  16. Direct imaging of rf waveguide modes via ultra-high field NMR

    CERN Document Server

    Tonyushkin, A; Van de Moortele, P -F; Adriany, G; Kiruluta, A

    2016-01-01

    We demonstrate an experimental method for direct 2D and 3D imaging of magnetic rf field distribution in metal waveguides based on traveling wave (TW) nuclear-magnetic resonance (NMR) imaging at ultra-high field (>7T). The typical apparatus would include an ultra-high field whole body or small bore NMR scanner, waveguide elements filled with NMR active dielectrics with predefined electric and magnetic properties, and TW rf transmit-receive probes. We validated the technique by obtaining TW magnetic-resonance (MR) images of the magnetic field distribution of the rf modes of circular waveguide filled with deionized water in a 16.4 T small-bore NMR scanner and compared the MR images with numerical simulations. Our NMR technique opens up a practical way of imaging of previously inaccessible rf field distribution of modes inside of various shapes metal waveguides with inserted dielectric objects, including waveguide mode converters and transformers.

  17. Enhancing ultra-high CPV passive cooling using least-material finned heat sinks

    Science.gov (United States)

    Micheli, Leonardo; Fernandez, Eduardo F.; Almonacid, Florencia; Reddy, K. S.; Mallick, Tapas K.

    2015-09-01

    Ultra-high concentrating photovoltaic (CPV) systems aim to increase the cost-competiveness of CPV by increasing the concentrations over 2000 suns. In this work, the design of a heat sink for ultra-high concentrating photovoltaic (CPV) applications is presented. For the first time, the least-material approach, widely used in electronics to maximize the thermal dissipation while minimizing the weight of the heat sink, has been applied in CPV. This method has the potential to further decrease the cost of this technology and to keep the multijunction cell within the operative temperature range. The designing procedure is described in the paper and the results of a thermal simulation are shown to prove the reliability of the solution. A prediction of the costs is also reported: a cost of 0.151/Wp is expected for a passive least-material heat sink developed for 4000x applications.

  18. Application of cold drawn lamellar microstructure for developing ultra-high strength wires

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Composite materials having lamellar structure are known to have a good combination of high strength and ductility. They are widely used in the fields of automobiles, civil engineering and construction, machines and many other industries. An application of lamellar microstructure for developing ultra-high strength steel wires was studied and discussed. Based on the experimental results,the relationships between the strength increase and microstructure development during the cold wire drawing were studied to reveal the strengthening mechanism. As cold drawing proceeds, the wire strength extremely increases, the microstructure changes from large single crystal lamellar structure to very fine polycrystalline lamellar one which has nano-sized grains, high dislocation density and amorphous regions. From the results obtained, it is concluded that heavy cold drawing technique is an effective method for lamellar composite to get high strength wires. Furthermore, formation process of the best microstructure for producing the ultra-high strength wires was also discussed.

  19. Lipid and Glycolipid Isomer Analyses Using Ultra-High Resolution Ion Mobility Spectrometry Separations

    Energy Technology Data Exchange (ETDEWEB)

    Wojcik, Roza; Webb, Ian; Deng, Liulin; Garimella, Sandilya; Prost, Spencer; Ibrahim, Yehia; Baker, Erin; Smith, Richard

    2017-01-01

    Understanding the biological mechanisms related to lipids and glycolipids is challenging due to the vast number of possible isomers. Mass spectrometry (MS) measurements are currently the dominant approach for studying and providing detailed information on lipid and glycolipid structures. However, difficulties in distinguishing many structural isomers (e.g. distinct acyl chain positions, double bond locations, as well as glycan isomers) inhibit the understanding of their biological roles. Here we utilized ultra-high resolution ion mobility spectrometry (IMS) separations based upon the use of traveling waves in a serpentine long path length multi-pass Structures for Lossless Manipulations (SLIM) to enhance isomer resolution. The multi-pass arrangement allowed separations ranging from ~16 m (1 pass) to ~470 m (32 passes) to be investigated for the distinction of lipids and glycolipids with extremely small structural differences. These ultra-high resolution SLIM IMS-MS analyses provide a foundation for exploring and better understanding isomer specific biological and disease processes.

  20. Temperature stability and microstructure of ultra-high intrinsic coercivity Nd-Fe-B magnets

    Institute of Scientific and Technical Information of China (English)

    HU Zhihua; CHENG Xinghua; ZHU Minggang; LI Wei; LIAN Fazeng

    2008-01-01

    The variations of intrinsic coercivity and remanence of sintered Nd-Fe-B magnets with ultra-high intrinsic coercivity were investigated.The results showed that the intrinsic coercivity and remanence declined simultaneously with increasing temperature,but the squareness of the magnets has hardly been changed.The temperature coefficients of remanence (α) and coercivity (β) for the magnets were calculated by two different methods,and the variations of the temperature coefficients and the microstructure of sintered Nd-Fe-B magnets were analyzed.The temperature coefficients of remanence (α) and coercivity (β) for the sintered magnets are very small,and the existence of free microstructure is necessary to obtain sintered Nd-Fe-B magnets with ultra-high intrinsic coercivity.

  1. Design of Ultra-High-Power-Density Machine Optimized for Future Aircraft

    Science.gov (United States)

    Choi, Benjamin B.

    2004-01-01

    The NASA Glenn Research Center's Structural Mechanics and Dynamics Branch is developing a compact, nonpolluting, bearingless electric machine with electric power supplied by fuel cells for future "more-electric" aircraft with specific power in the projected range of 50 hp/lb, whereas conventional electric machines generate usually 0.2 hp/lb. The use of such electric drives for propulsive fans or propellers depends on the successful development of ultra-high-power-density machines. One possible candidate for such ultra-high-power-density machines, a round-rotor synchronous machine with an engineering current density as high as 20,000 A/sq cm, was selected to investigate how much torque and power can be produced.

  2. Study of application technology of ultra-high speed computer to the elucidation of complex phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, Tomotsugu [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)

    1996-06-01

    The basic design of numerical information library in the decentralized computer network was explained at the first step of constructing the application technology of ultra-high speed computer to the elucidation of complex phenomena. Establishment of the system makes possible to construct the efficient application environment of ultra-high speed computer system to be scalable with the different computing systems. We named the system Ninf (Network Information Library for High Performance Computing). The summary of application technology of library was described as follows: the application technology of library under the distributed environment, numeric constants, retrieval of value, library of special functions, computing library, Ninf library interface, Ninf remote library and registration. By the system, user is able to use the program concentrating the analyzing technology of numerical value with high precision, reliability and speed. (S.Y.)

  3. Widespread inflammation in CLIPPERS syndrome indicated by autopsy and ultra-high-field 7T MRI

    DEFF Research Database (Denmark)

    Blaabjerg, Morten; Ruprecht, Klemens; Sinnecker, Tim

    2016-01-01

    OBJECTIVE: To examine if there is widespread inflammation in the brain of patients with chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome by using histology and ultra-high-field MRI at 7.0T. METHODS: We performed a detailed neuropath......OBJECTIVE: To examine if there is widespread inflammation in the brain of patients with chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome by using histology and ultra-high-field MRI at 7.0T. METHODS: We performed a detailed...... in the brainstem, which were not seen on 3.0T MRI. This corresponded to neuropathologic detection of axonal injury in the autopsy case. CONCLUSION: Our findings suggest more widespread perivascular inflammation and postinflammatory axonal injury in patients with CLIPPERS....

  4. Design and performance of ultra-high-density optical fiber cable with rollable optical fiber ribbons

    Science.gov (United States)

    Hogari, Kazuo; Yamada, Yusuke; Toge, Kunihiro

    2010-08-01

    This paper proposes a novel ultra-high-density optical fiber cable that employs rollable optical fiber ribbons. The cable has great advantages in terms of cable weight and diameter, and fiber splicing workability. Moreover, it will be easy to install in a small space in underground ducts and on residential and business premises. The structural design of the rollable optical fiber ribbon is evaluated theoretically and experimentally, and an optimum adhesion pitch P in the longitudinal direction is obtained. In addition, we examined the performance of ultra-high-density cables with a small diameter that employ rollable optical fiber ribbons and bending-loss insensitive optical fibers. The transmission, mechanical and mid-span access performance of these cables was confirmed to be excellent.

  5. Enhancing ultra-high CPV passive cooling using least-material finned heat sinks

    Energy Technology Data Exchange (ETDEWEB)

    Micheli, Leonardo, E-mail: lm409@exeter.ac.uk; Mallick, Tapas K., E-mail: T.K.Mallick@exeter.ac.uk [Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE (United Kingdom); Fernandez, Eduardo F., E-mail: E.Fernandez-Fernandez2@exeter.ac.uk [Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE (United Kingdom); Centre of Advanced Studies in Energy and Environment, University of Jaen, Jaen 23071 (Spain); Almonacid, Florencia, E-mail: facruz@ujaen.es [Centre of Advanced Studies in Energy and Environment, University of Jaen, Jaen 23071 (Spain); Reddy, K. S., E-mail: ksreddy@iitm.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, 600036 (India)

    2015-09-28

    Ultra-high concentrating photovoltaic (CPV) systems aim to increase the cost-competiveness of CPV by increasing the concentrations over 2000 suns. In this work, the design of a heat sink for ultra-high concentrating photovoltaic (CPV) applications is presented. For the first time, the least-material approach, widely used in electronics to maximize the thermal dissipation while minimizing the weight of the heat sink, has been applied in CPV. This method has the potential to further decrease the cost of this technology and to keep the multijunction cell within the operative temperature range. The designing procedure is described in the paper and the results of a thermal simulation are shown to prove the reliability of the solution. A prediction of the costs is also reported: a cost of 0.151$/W{sub p} is expected for a passive least-material heat sink developed for 4000x applications.

  6. Quality of silicon convex lenses fabricated by ultra-high precision diamond machining

    Directory of Open Access Journals (Sweden)

    Abou-El-Hossein, K.

    2013-05-01

    Full Text Available Infra-red optical components are made mainly from hard and brittle materials such as germanium and silicon. Silicon machining is characterised by some difficulties when ultra-high precision machined by mono-crystalline single-point diamond. Accelerated tool wear and machined-surface deterioration may take place if the machining parameters are not properly selected. In this study, we conducted a machining test on an ultra-high precision machine tool, using ductile regime cutting conditions when fabricating a convex surface on a silicon lens of aperture of 60 mm diameter, and using a mono-crystalline diamond. It was found that the cutting conditions for shaping a convex surface of 500 mm radius resulted in good form accuracy. However, more attention should be paid to optimising the holding force of the vacuum chuck employed.

  7. Plasma Wind Tunnel Testing of Ultra High Temperature Ceramics: Experiments And Numerical Correlation

    OpenAIRE

    Di Maso, Andrea

    2009-01-01

    The thesis is focused on the aerothermodynamic and oxidation behaviour of ultra-high-temperature Ceramic (UHTC) for aerospace applications. UHTC are very high temperature resistant (>2000K) materials, with good chemical inertness and mechanical properties. These materials could be used for next generation aerospace and hypersonic vehicles. The arc jet plasma wind tunnel available at the Department of Aerospace Engineering of Naples (DIAS) is able to reproduce specific total enthalpies and sta...

  8. Synthesis and Processing of Ultra-High Temperature Metal Carbide and Metal Diboride Nanocomposite Materials

    Science.gov (United States)

    2008-04-15

    Synthesis and Processing of Ultra-High Temperature Metal Carbide and Metal Diboride Nanocomposite Materials Final Performance Report Contract Number...sintered commercially-available powders. Each project is summarized below: Synthesis : Zirconium diboride and a zirconium diboride/tantalum diboride...mixture were synthesized by solution-based processing. Zirconium n-propoxide was refluxed with 2,4-pentanedione to form zirconium diketonate . This compound

  9. Ultra-High Performance ‘Ductile’ Concrete Technology Toward Sustainable Construction

    OpenAIRE

    2011-01-01

    This paper briefly presents an overview of the material characteristics of a Malaysia blend of ultra-high performance ductile concrete (UHPdC) know as DURA®. Examples of the environmental impact calculations of UHPdC structures compared to that of conventional reinforced concrete design are presented. The comparison studies show that many structures constructed from UHPdC are generally more environmentally sustainable than built of the conventional reinforced concrete with respect to the redu...

  10. Sintering and properties of Ultra High Temperature Ceramics for aerospace applications

    OpenAIRE

    Justin, J.F.

    2013-01-01

    The Ultra High Temperature Ceramics (UHTCs) represent a very interesting family of materials and therefore they are the subject of increasing attention from different engineering sectors and notably the aerospace industry. Indeed, hypersonic flights, re-entry vehicles, propulsion applications and so on, require new materials that can perform in oxidizing or corrosive atmospheres at temperatures higher than 2000°C and sometimes, for long life-time. To fulfil these requirements, UHTCs seems to ...

  11. Development of UHTC- Ultra-high-temperature ceramics for aerospace and industrial applications

    OpenAIRE

    Bellosi, Alida

    2009-01-01

    Zirconium and Hafnium diborides and carbides belong to the class of Ultra-High-Temperature Ceramics (UHTC) for their high melting point (2700-3900?C). The interest on these materials is due to the unique combination of properties 8High hardness, high electrical and thermal conductivity, chemical inertness). They constitute a clss of promising materials for HT applications in industrial secors like foundry, refractory or nuclear plants. Applications are also found in aerospace industry: leadin...

  12. Ultra-High-Temperature-Ceramics: potentialities and barriers to the application in hot structures

    OpenAIRE

    Bellosi, Alida

    2009-01-01

    High performance Ultra-High-Temperature Composites (based on zirconium-, hafnium-, tantalum- borides and carbides) are characterized by relevant and unique thermo-physical and thermo-mechanical properties, suitable for applications in thermo-protection systems for aerospace applications. In spite of the difficult sinterability of borides and carbides of Zr, Hf, Ta, recent results highlighted that UHTC ceramics can be successfully produced with full density, fine and uniform microstructure and...

  13. Inactivation of Bacillus spores inoculated in milk by Ultra High Pressure Homogenization.

    Science.gov (United States)

    Amador Espejo, Genaro Gustavo; Hernández-Herrero, M M; Juan, B; Trujillo, A J

    2014-12-01

    Ultra High-Pressure Homogenization treatments at 300 MPa with inlet temperatures (Ti) of 55, 65, 75 and 85 °C were applied to commercial Ultra High Temperature treated whole milk inoculated with Bacillus cereus, Bacillus licheniformis, Bacillus sporothermodurans, Bacillus coagulans, Geobacillus stearothermophilus and Bacillus subtilis spores in order to evaluate the inactivation level achieved. Ultra High-Pressure Homogenization conditions at 300 MPa with Ti = 75 and 85 °C were capable of a spore inactivation of ∼5 log CFU/mL. Furthermore, under these processing conditions, commercial sterility (evaluated as the complete inactivation of the inoculated spores) was obtained in milk, with the exception of G. stearothermophilus and B. subtilis treated at 300 MPa with Ti = 75 °C. The results showed that G. stearothermophilus and B. subtilis have higher resistance to the Ultra High-Pressure Homogenization treatments applied than the other microorganisms inoculated and that a treatment performed at 300 MPa with Ti = 85 °C was necessary to completely inactivate these microorganisms at the spore level inoculated (∼1 × 10(6) CFU/mL). Besides, a change in the resistance of B. licheniformis, B. sporothermodurans, G. stearothermophilus and B. subtilis spores was observed as the inactivation obtained increased remarkably in treatments performed with Ti between 65 and 75 °C. This study provides important evidence of the suitability of UHPH technology for the inactivation of spores in high numbers, leading to the possibility of obtaining commercially sterile milk.

  14. Horizontal Shear Transfer Between Ultra High Performance Concrete And Lightweight Concrete

    OpenAIRE

    Banta, Timothy E.

    2005-01-01

    Ultra high performance concrete, specifically Ductal® concrete, has begun to revolutionize the bridge design industry. This extremely high strength material has given smaller composite sections the ability to carry larger loads. As the forces being transferred through composite members are increasing in magnitude, it is vital that the equations being used for design are applicable for use with the new materials. Of particular importance is the design of the horizontal shear reinforcement ...

  15. Surface modification of ultra-high molecular weight polyethylene for joint prosthesis and sports applications

    Institute of Scientific and Technical Information of China (English)

    H.Dong

    2004-01-01

    The recent progresses in the surfaee modification of ultra high molecular weight polyethylene (UHMWPE) using such advanced surface modification technologies as conventional ion implantation (CⅡ), new plasma immersion ion implantation (PⅢ) and novel active screen plasma (ASP), were all reported. Significantly improved wear resistance was achieved, which has great potential for extending the life-span of joint replacement prostheses and enhancing the performance of such sports equipment as skis and snowboards.

  16. Increasing the wear resistance of ultra-high molecular weight polyethylene by adding solid lubricating fillers

    Energy Technology Data Exchange (ETDEWEB)

    Panin, S. V., E-mail: svp@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Kornienko, L. A.; Poltaranin, M. A.; Ivanova, L. R. [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Suan, T. Nguen [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2014-11-14

    In order to compare effectiveness of adding solid lubricating fillers for polymeric composites based on ultra-high molecular weight polyethylene (UHMWPE) with graphite, molybdenum disulfide and polytetrafluoroethylene, their tribotechnical characteristics under dry friction, boundary lubrication and abrasive wearing were investigated. The optimal weight fractions of fillers in terms of improving wear resistance have been determined. The supramolecular structure and topography of wear track surfaces of UHMWPE-based composites with different content of fillers have been studied.

  17. Radiation cross-linking in ultra-high molecular weight polyethylene for orthopaedic applications

    OpenAIRE

    Oral, Ebru; Muratoglu, Orhun K.

    2007-01-01

    The motivation for radiation cross-linking of ultra-high molecular weight polyethylene (UHMWPE) is to increase its wear resistance to be used as bearing surfaces for total joint arthroplasty. However, radiation also leaves behind long-lived residual free radicals in this polymer, the reactions of which can detrimentally affect mechanical properties. In this review, we focus on the radiation cross-linking and oxidative stability of first and second generation highly cross-linked UHMWPEs develo...

  18. Ultra-high aspect ratio replaceable AFM tips using deformation-suppressed focused ion beam milling

    DEFF Research Database (Denmark)

    Savenko, Alexey; Yildiz, Izzet; Petersen, Dirch Hjorth;

    2013-01-01

    Fabrication of ultra-high aspect ratio exchangeable and customizable tips for atomic force microscopy (AFM) using lateral focused ion beam (FIB) milling is presented. While on-axis FIB milling does allow high aspect ratio (HAR) AFM tips to be defined, lateral milling gives far better flexibility...... FIB milling strategies for obtaining sharper tips are discussed. Finally, assembly of the HAR tips on a custom-designed probe as well as the first AFM scanning is shown....

  19. Research and Application of WCF Technology in Data Acquisition of Ultra-high Speed Packaging Machine

    Directory of Open Access Journals (Sweden)

    Qian Jie

    2016-01-01

    Full Text Available By introducing WCF technology on data acquisition of ultra-high speed packaging machine, data acquisition system reads dates of machine in polling mode through the WCF client, which can achieve accurate data collection, and effectively isolate the data acquisition system and the machine control system. It enhances the security of data interaction between systems, but also reduces the coupling degree between systems.

  20. Ultra High Molecular Weight Polyethylene/Graphene Oxide Nanocomposites: Thermal, Mechanical and Wettability Characterisation

    OpenAIRE

    2015-01-01

    Ultra high molecular weight polyethylene (UHMWPE) is the material most commonly used among hard-on-soft bearings in artificial joints. However, the eventual failure of joint implants has been directly related to the wear and oxidation resistance of UHMWPE. The development of novel materials with improved wear and oxidative characteristics has generated great interest in the orthopaedic community and numerous carbon nanostructures have been investigated in the last years due to their excellent...

  1. Single Straight Steel Fiber Pullout Characterization in Ultra-High Performance Concrete

    OpenAIRE

    Black, Valerie Mills

    2014-01-01

    This thesis presents results of an experimental investigation to characterize single straight steel fiber pullout in Ultra-High Performance Concrete (UHPC). Several parameters were explored including the distance of fibers to the edge of specimen, distance between fibers, and fiber volume in the matrix. The pullout load versus slip curve was recorded, from which the pullout work and maximum pullout load for each series of parameters were obtained. The curves were fitted to an e...

  2. Ultra-high degree spectral modelling of Earth and planetary topography

    Science.gov (United States)

    Rexer, Moritz; Hirt, Christian

    2016-04-01

    New methods for ultra-high degree spherical harmonic analyses and syntheses have been developed and studied over the past years. The focus group "High-resolution Gravity Modelling", established in 2013 at TU Munich, has implemented ultra-high degree spectral modelling techniques and used successfully to transform high-resolution topography grids of Earth, Moon and Mars into spherical harmonics. For Earth, a new set of 1 arc-min topography models, developed by our group and released under the name Earth2014, was expanded into a spherical harmonic series to degree 10,800. For the 15 arc-sec resolution SRTM15_plus topography and bathymetry, a spectral resolution of degree 43,200 was achieved. For Moon and Mars, topography grids from laser altimetry were harmonically analysed up to degree ~46,000. The spectral representations of the topography grids presented in this contribution are required in the context of spectral gravity forward modelling with ultra-high degree, where the topographic potential is computed as a function of the spherical harmonic series of the topography and its integer powers. References: Hirt, C., and M. Rexer (2015) Earth2014: 1 arc-min shape, topography, bedrock and ice-sheet models - available as gridded data and degree-10,800 spherical harmonics, International Journal of Applied Earth Observation and Geoinformation 39, 103-112, doi:10.1016/j.jag.2015.03.001. Rexer, M. and C. Hirt (2015), Ultra-high degree surface spherical harmonic analysis using the Gauss-Legendre and the Driscoll/Healy quadrature theorem and application to planetary topography models of Earth, Moon and Mars. Surveys in Geophysics 36(6), 803-830, doi: 10.1007/s10712-015-9345-z.

  3. Reactive Fusion Welding for Ultra-High Temperature Ceramic Composite Joining

    Science.gov (United States)

    2015-03-16

    INTRODUCTION Zirconium diboride (ZrB2) is ceramic material belonging to the group of materials known as ultra-high temperature ceramics (UHTCs), where UHTCs...expended during the diffusion of C from the graphite spacer. This occurs as the enthalpy of fusion (Hf) and mixing (Hmix) are expected to be positive...ZrB2 Ceramics ( Contributed Oral Presentation) Authors: Derek King, Greg E. Hilmas, and William G. Fahrenholtz Plasma arc welding was used to join

  4. Ultra High Bypass Ratio Engine Research for Reducing Noise, Emissions, and Fuel Consumption

    Science.gov (United States)

    Hughes, Christopher E.; Schweitzer, Jeff

    2007-01-01

    A pictorial history of NASA development of advanced engine technologies for reducing environmental emissions and increasing performance from the 1970s to 2000s is presented. The goals of the Subsonic Fixed Wing Program portion of the NASA Fundamental Aeronautics Program are discussed, along with the areas of investigation currently being pursued by the Ultra High Bypass Partnership Element of the Subsonic Fixed Wing Program.

  5. Simulation of press-forming for automobile part using ultra high tension steel

    Directory of Open Access Journals (Sweden)

    Tanabe I.

    2012-08-01

    Full Text Available In recent years, ultra high tension steel has gradually been used in the automobile industry. The development of press-forming technology is now essential by reason of its high productivity and high product quality. In this study, tensile tests were performed with a view to understanding the material properties. Press-forming tests were then carried out with regard to the behaviors of spring back and deep-drawability, and manufacturing a real product. The ultra high tension steel used in the experiments had a thickness of 1 mm and a tensile strength of 1000 MPa. Finally, simulations of spring back, deep-drawability and manufacturing a real product in ultra high tension steel were conducted and evaluated in order to calculate the optimum-press-forming conditions and the optimum shape of the die. FEM with non-linear and dynamic analysis using Euler-Lagrange’s element was used for the simulations. It is concluded from the results that (1 the simulations conformed to the results of the experiments (2 the simulations proved very effective for calculating the optimum press conditions and die shape.

  6. Interpersonal sensitivity and functioning impairment in youth at ultra-high risk for psychosis.

    Science.gov (United States)

    Masillo, A; Valmaggia, L R; Saba, R; Brandizzi, M; Lindau, J F; Solfanelli, A; Curto, M; Narilli, F; Telesforo, L; Kotzalidis, G D; Di Pietro, D; D'Alema, M; Girardi, P; Fiori Nastro, P

    2016-01-01

    A personality trait that often elicits poor and uneasy interpersonal relationships is interpersonal sensitivity. The aim of the present study was to explore the relationship between interpersonal sensitivity and psychosocial functioning in individuals at ultra-high risk for psychosis as compared to help-seeking individuals who screened negative for an ultra-high risk of psychosis. A total sample of 147 adolescents and young adult who were help seeking for emerging mental health problems participated in the study. The sample was divided into two groups: 39 individuals who met criteria for an ultra-high-risk mental state (UHR), and 108 (NS). The whole sample completed the Interpersonal Sensitivity Measure (IPSM) and the Global Functioning: Social and Role Scale (GF:SS; GF:RS). Mediation analysis was used to explore whether attenuated negative symptoms mediated the relationship between interpersonal sensitivity and social functioning. Individuals with UHR state showed higher IPSM scores and lower GF:SS and GF:RS scores than NS participants. A statistically negative significant correlation between two IPSM subscales (Interpersonal Awareness and Timidity) and GF:SS was found in both groups. Our results also suggest that the relationship between the aforementioned aspects of interpersonal sensitivity and social functioning was not mediated by negative prodromal symptoms. This study suggests that some aspects of interpersonal sensitivity were associated with low level of social functioning. Assessing and treating interpersonal sensitivity may be a promising therapeutic target to improve social functioning in young help-seeking individuals.

  7. Plasmonic metamaterial for electromagnetically induced transparency analogue and ultra-high figure of merit sensor

    Science.gov (United States)

    Wu, Dong; Liu, Yumin; Yu, Li; Yu, Zhongyuan; Chen, Lei; Li, Ruifang; Ma, Rui; Liu, Chang; Zhang, Jinqiannan; Ye, Han

    2017-03-01

    In this work, using finite-difference time-domain method, we propose and numerically demonstrate a novel way to achieve electromagnetically induced transparency (EIT) phenomenon in the reflection spectrum by stacking two different types of coupling effect among different elements of the designed metamaterial. Compared with the conventional EIT-like analogues coming from only one type of coupling effect between bright and dark meta-atoms on the same plane, to our knowledge the novel approach is the first to realize the optically active and precise control of the wavelength position of EIT-like phenomenon using optical metamaterials. An on-to-off dynamic control of the EIT-like phenomenon also can be achieved by changing the refractive index of the dielectric substrate via adjusting an optical pump pulse. Furthermore, in near infrared region, the metamaterial structure can be operated as an ultra-high resolution refractive index sensor with an ultra-high figure of merit (FOM) reaching 3200, which remarkably improve the FOM value of plasmonic refractive index sensors. The novel approach realizing EIT-like spectral shape with easy adjustment to the working wavelengths will open up new avenues for future research and practical application of active plasmonic switch, ultra-high resolution sensors and active slow-light devices.

  8. Properties and Microstructural Characteristic of Kaolin Geopolymer Ceramics with Addition of Ultra High Molecular Weight Polyethylene

    Science.gov (United States)

    Ahmad, Romisuhani; Bakri Abdullah, Mohd Mustafa Al; Hussin, Kamarudin; Sandu, Andrei Victor; Binhussain, Mohammed; Ain Jaya, Nur

    2016-06-01

    In this paper, the mechanical properties and microstructure of kaolin geopolymer ceramics with addition of Ultra High Molecular Weight Polyethylene were studied. Inorganic polymers based on alumina and silica polysialate units were synthesized at room temperature from kaolin and sodium silicate in a highly alkaline medium, followed by curing and drying at 80 °C. Alkaline activator was formed by mixing the 12 M NaOH solution with sodium silicate at a ratio of 0.24. Addition of Ultra High Molecular Weight Polyethylene to the kaolin geopolymer are fabricated with Ultra High Molecular Weight Polyethylene content of 2, 4, 6 and 8 (wt. %) by using powder metallurgy method. The samples were heated at 1200 °C and the strength and morphological were tested. It was found that the flexural strength for the kaolin geopolymer ceramics with addition of UHMWPE were improved and generally increased with the increasing of UHMWPE loading. The result revealed that the optimum flexural strength was obtained at UHMWPE loading of 4 wt. % (92.1 MPa) and the flexural strength started to decrease. Microstructural analysis showed the samples appeared to have more number of pores and connected of pores increased with the increasing of UHMWPE content.

  9. Flexural Strength Evaluation of Reinforced Concrete Members with Ultra High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Baek-Il Bae

    2016-01-01

    Full Text Available Flexural strength evaluation models for steel fiber reinforced ultra high strength concrete were suggested and evaluated with test results. Suggested flexural strength models were composed of compression stress blocks and tension stress blocks. Rectangular stress block, triangular stress block, and real distribution shape of stress were used on compression side. Under tension, rectangular stress block distributed to whole area of tension side and partial area of tension side was used. The last model for tension side is realistic stress distribution. All these models were verified with test result which was carried out in this study. Test was conducted by four-point loading with 2,000 kN actuator for slender beam specimen. Additional verifications were carried out with previous researches on flexural strength of steel fiber reinforced concrete or ultra high strength concrete. Total of 21 test specimens were evaluated. As a result of comparison for flexural strength of section, neutral axis depth at ultimate state, models with triangular compression stress block, and strain-softening type tension stress block can be used as exact solution for ultra high performance concrete. For the conservative and convenient design of section, modified rectangular stress block model can be used with strain softening type tension stress block.

  10. Comparison of ultra-high performance supercritical fluid chromatography and ultra-high performance liquid chromatography for the separation of spirostanol saponins.

    Science.gov (United States)

    Zhu, Ling-Ling; Zhao, Yang; Xu, Yong-Wei; Sun, Qing-Long; Sun, Xin-Guang; Kang, Li-Ping; Yan, Ren-Yi; Zhang, Jie; Liu, Chao; Ma, Bai-Ping

    2016-02-20

    Spirostanol saponins are important active components of some herb medicines, and their isolation and purification are crucial for the research and development of traditional Chinese medicines. We aimed to compare the separation of spirostanol saponins by ultra-high performance supercritical fluid chromatography (UHPSFC) and ultra-high performance liquid chromatography (UHPLC). Four groups of spirostanol saponins were separated respectively by UHPSFC and UHPLC. After optimization, UHPSFC was performed with a HSS C18 SB column or a Diol column and with methanol as the co-solvent. A BEH C18 column and mobile phase containing water (with 0.1% formic acid) and acetonitrile were used in UHPLC. We found that UHPSFC could be performed automatically and quickly. It is effective in separating the spirostanol saponins which share the same aglycone and vary in sugar chains, and is very sensitive to the number and the position of hydroxyl groups in aglycones. However, the resolution of spirostanol saponins with different aglycones and the same sugar moiety by UHPSFC was not ideal and could be resolved by UHPLC instead. UHPLC is good at differentiating the variation in aglycones, and is influenced by double bonds in aglycones. Therefore, UHPLC and UHPSFC are complementary in separating spirostanol saponins. Considering the naturally produced spirostanol saponins in herb medicines are different both in aglycones and in sugar chains, a better separation can be achieved by combination of UHPLC and UHPSFC. UHPSFC is a powerful technique for improving the resolution when UHPLC cannot resolve a mixture of spirostanol saponins and vice versa.

  11. Smaller Footprint Drilling System for Deep and Hard Rock Environments; Feasibility of Ultra-High-Speed Diamond Drilling

    Energy Technology Data Exchange (ETDEWEB)

    TerraTek, A Schlumberger Company

    2008-12-31

    The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high rotational speeds (greater than 10,000 rpm). The work includes a feasibility of concept research effort aimed at development that will ultimately result in the ability to reliably drill 'faster and deeper' possibly with smaller, more mobile rigs. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration (ROP) rock cutting with substantially lower inputs of energy and loads. The significance of the 'ultra-high rotary speed drilling system' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm - usually well below 5,000 rpm. This document provides the progress through two phases of the program entitled 'Smaller Footprint Drilling System for Deep and Hard Rock Environments: Feasibility of Ultra-High-Speed Diamond Drilling' for the period starting 30 June 2003 and concluding 31 March 2009. The accomplishments of Phases 1 and 2 are summarized as follows: (1) TerraTek reviewed applicable literature and documentation and convened a project kick-off meeting with Industry Advisors in attendance (see Black and Judzis); (2) TerraTek designed and planned Phase I bench scale experiments (See Black and Judzis). Improvements were made to the loading mechanism and the rotational speed monitoring instrumentation. New drill bit designs were developed to provided a more consistent product with consistent performance. A test matrix for the final core bit testing program was completed; (3) TerraTek concluded small-scale cutting performance tests; (4

  12. Surface Anchoring of Nematic Phase on Carbon Nanotubes: Nanostructure of Ultra-High Temperature Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ogale, Amod A

    2012-04-27

    Nuclear energy is a dependable and economical source of electricity. Because fuel supply sources are available domestically, nuclear energy can be a strong domestic industry that can reduce dependence on foreign energy sources. Commercial nuclear power plants have extensive security measures to protect the facility from intruders [1]. However, additional research efforts are needed to increase the inherent process safety of nuclear energy plants to protect the public in the event of a reactor malfunction. The next generation nuclear plant (NGNP) is envisioned to utilize a very high temperature reactor (VHTR) design with an operating temperature of 650-1000°C [2]. One of the most important safety design requirements for this reactor is that it must be inherently safe, i.e., the reactor must shut down safely in the event that the coolant flow is interrupted [2]. This next-generation Gen IV reactor must operate in an inherently safe mode where the off-normal temperatures may reach 1500°C due to coolant-flow interruption. Metallic alloys used currently in reactor internals will melt at such temperatures. Structural materials that will not melt at such ultra-high temperatures are carbon/graphtic fibers and carbon-matrix composites. Graphite does not have a measurable melting point; it is known to sublime starting about 3300°C. However, neutron radiation-damage effects on carbon fibers are poorly understood. Therefore, the goal of this project is to obtain a fundamental understanding of the role of nanotexture on the properties of resulting carbon fibers and their neutron-damage characteristics. Although polygranular graphite has been used in nuclear environment for almost fifty years, it is not suitable for structural applications because it do not possess adequate strength, stiffness, or toughness that is required of structural components such as reaction control-rods, upper plenum shroud, and lower core-support plate [2,3]. For structural purposes, composites

  13. Laser Beam Welding of Ultra-high Strength Chromium Steel with Martensitic Microstructure

    Science.gov (United States)

    Dahmen, Martin; Janzen, Vitalij; Lindner, Stefan; Wagener, Rainer

    A new class of steels is going to be introduced into sheet manufacturing. Stainless ferritic and martensitic steels open up opportunities for sheet metal fabrication including hot stamping. Strengths of up to 2 GPa at fracture elongations of 15% can be attained through this. Welding of these materials, as a result, became a challenge. Energy-reduced welding methods with in-situ heat treatment are required in order to ensure the delicate and complex heat control. Laser beam welding is the joining technique of choice to supply minimum heat input to the fusion process and to apply efficient heat control. For two application cases, tailored blank production in as-rolled condition and welding during assembly in hot stamped condition, welding processes have been developed. The welding suitability is shown through metallurgical investigations of the welds. Crash tests based on the KS-II concept as well as fatigue tests prove the applicability of the joining method.

  14. FLOAT - development of new flexible UHPC. Final report. [Ultra High Performance Fibre Reinforced Concrete

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    The current project is a preliminary study intended to clarify the background and give a better basis for an evaluation of the risks and possible rewards of funding a full project with the overall purpose of developing and testing a new concept for wave energy floaters, made of Ultra High Performance Fibre Reinforced Concrete (UHPC), as an enabling technology for the establishment of competitive wave energy production (FLOAT). As an initial step for this preliminary study of FLOAT an investigation has been undertaken in relation to preliminary design of 2 types of floaters, essential properties of UHPFRC - and identification of necessary developments, compilation of existing data from off shore applications and analysis of effect on Cost Of Energy. Preliminary float design and economical considerations - is a theoretical and numerical study including preliminary float designs and cost estimates. It aims at making a first comparison between the different materials options for DEXA and Wave Star floats and giving a first judgement about the suitability of CRC concrete. This is done through a qualitative assessment of pros and cons of different materials for both types of floats and a design study of the Dexa Wave float. It is concluded that the requirements for the Dexa Wave float are so that CRC is not able to compete with conventional concrete for the best and most cost effective solution. The good durability (leading to low maintenance costs), the mechanical properties and the ductility of CRC are not important enough to offset the increased cost for this float. For Wave Star on the other hand, there are significant advantages in using CRC as the only other option in this case is fibre glass, which is a much more expensive product. An investigation was made of methods of optimizing the properties of CRC - customizing them for particular applications in WEC's. The method of optimization has been to change the types of fibres in the mix, and it is demonstrated

  15. Ultra-High Efficiency and Low-Emissions Combustion Technology for Manufacturing Industries

    Energy Technology Data Exchange (ETDEWEB)

    Atreya, Arvind

    2013-04-15

    -dimensional parameters controlling RFC in furnaces were identified. These are: (i) The Boltzmann number; (ii) The Damkohler number, (iii) The dimensionless Arrhenius number, and (iv) The equivalence ratio. Together they define the parameter space where RFC is possible. It was also found that the Damkohler number must be small for RFC to exist and that the Boltzmann number expands the RFC domain. The experimental data obtained during the course of this work agrees well with the predictions made by the theoretical analysis. Interestingly, the equivalence ratio dependence shows that it is easier to establish RFC for rich mixtures than for lean mixtures. This was also experimentally observed. Identifying the parameter space for RFC is necessary for controlling the RFC furnace operation. It is hoped that future work will enable the methodology developed here to be applied to the operation of real furnaces, with consequent improvement in efficiency and pollutant reduction. To reiterate, the new furnace combustion technology developed enables intense radiation from combustion products and has many benefits: (i) Ultra-High Efficiency and Low-Emissions; (ii) Uniform and intense radiation to substantially increase productivity; (iii) Oxygen-free atmosphere to reduce dross/scale formation; (iv) Provides multi-fuel capability; and (v) Enables carbon sequestration if pure oxygen is used for combustion.

  16. Ultra high risk of psychosis on committal to a young offender prison: an unrecognised opportunity for early intervention

    OpenAIRE

    Flynn Darran; Smith Damian; Quirke Luke; Monks Stephen; Kennedy Harry G

    2012-01-01

    Abstract Background The ultra high risk state for psychosis has not been studied in young offender populations. Prison populations have higher rates of psychiatric morbidity and substance use disorders. Due to the age profile of young offenders one would expect to find a high prevalence of individuals with pre-psychotic or ultra-high risk mental states for psychosis (UHR). Accordingly young offender institutions offer an opportunity for early interventions which could result in improved long ...

  17. Detection of ultra-high-energy cosmic radiation at the Pierre Auger Observatory, theoretical study of its propagation through extragalactic space; Detection des rayons cosmiques ultra-energetiques avec l'observatoire Pierre Auger et etude theorique de leur propagation dans le milieu extragalactique

    Energy Technology Data Exchange (ETDEWEB)

    Allard, D

    2004-10-01

    The Pierre Auger observatory's main aim is to observe the ultra-energetic cosmic ray spectrum with high statistics. Indeed, the spectrum around 10{sup 20} eV is so far only poorly known, due to low statistics and the expected GZK (Gneisen-Zatsepin-Kuzmin) cut-off is for the time being not clearly observed. The first part will deal with propagation of charged (protons and nuclei) ultra-energetic cosmic rays in the extragalactic medium. We will investigate the influence of physical parameters, such as the composition of cosmic ray fluxes, on the highest energy spectrum shape. The influence of the turbulent extragalactic magnetic fields on the spectrum of the clusters will also be studied. We will also investigate the possibility to observe gamma ray bursts with the Pierre Auger Observatory by using the single particle technique. We will show how galactic gamma ray bursts could become a persistent and quasi-isotropic source due to the 'Compton trail' induced by Compton scattering of the primary photon beam in the interstellar medium. In the section devoted to simulations, we will develop methods to reconstruct air showers and identify primary cosmic rays. We will also study the aperture of the Surface Detector of the Pierre Auger observatory. Finally, we will use the methods developed in the previous chapters to analyze the data of the year 2004 and will give preliminary results. (author)

  18. Ultra-high-resolution inelastic X-ray scattering at high-repetition-rate self-seeded X-ray free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Chubar, Oleg [Brookhaven National Laboratory, Upton, NY 11973 (United States); Geloni, Gianluca [European X-ray Free-Electron Laser, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Kocharyan, Vitali [Deutsches Elektronen-Synchrotron, 22761 Hamburg (Germany); Madsen, Anders [European X-ray Free-Electron Laser, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Saldin, Evgeni; Serkez, Svitozar [Deutsches Elektronen-Synchrotron, 22761 Hamburg (Germany); Shvyd’ko, Yuri, E-mail: shvydko@aps.anl.gov [Argonne National Laboratory, Argonne, IL 60439 (United States); Sutter, John [Diamond Light Source Ltd, Didcot OX11 0DE (United Kingdom)

    2016-02-12

    This article explores novel opportunities for ultra-high-resolution inelastic X-ray scattering (IXS) at high-repetition-rate self-seeded XFELs. These next-generation light sources are promising a more than three orders of magnitude increase in average spectral flux compared with what is possible with storage-ring-based radiation sources. In combination with the advanced IXS spectrometer described here, this may become a real game-changer for ultra-high-resolution X-ray spectroscopies, and hence for the studies of dynamics in condensed matter systems. Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm{sup −1} spectral and momentum-transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm{sup −1} are required to close the gap in energy–momentum space between high- and low-frequency probes. It is shown that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a 100-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than what is possible with storage-ring-based radiation sources. Wave-optics calculations show that about 7 × 10{sup 12} photons s{sup −1} in a 90 µeV bandwidth can be achieved on the sample. This will provide unique new possibilities for dynamics studies by IXS.

  19. Ultra-high vacuum surface analysis study of rhodopsin incorporation into supported lipid bilayers.

    Science.gov (United States)

    Michel, Roger; Subramaniam, Varuni; McArthur, Sally L; Bondurant, Bruce; D'Ambruoso, Gemma D; Hall, Henry K; Brown, Michael F; Ross, Eric E; Saavedra, S Scott; Castner, David G

    2008-05-06

    Planar supported lipid bilayers that are stable under ambient atmospheric and ultra-high-vacuum conditions were prepared by cross-linking polymerization of bis-sorbylphosphatidylcholine (bis-SorbPC). X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to investigate bilayers that were cross-linked using either redox-initiated radical polymerization or ultraviolet photopolymerization. The redox method yields a more structurally intact bilayer; however, the UV method is more compatible with incorporation of transmembrane proteins. UV polymerization was therefore used to prepare cross-linked bilayers with incorporated bovine rhodopsin, a light-activated, G-protein-coupled receptor (GPCR). A previous study (Subramaniam, V.; Alves, I. D.; Salgado, G. F. J.; Lau, P. W.; Wysocki, R. J.; Salamon, Z.; Tollin, G.; Hruby, V. J.; Brown, M. F.; Saavedra, S. S. J. Am. Chem. Soc. 2005, 127, 5320-5321) showed that rhodopsin retains photoactivity after incorporation into UV-polymerized bis-SorbPC, but did not address how the protein is associated with the bilayer. In this study, we show that rhodopsin is retained in supported bilayers of poly(bis-SorbPC) under ultra-high-vacuum conditions, on the basis of the increase in the XPS nitrogen concentration and the presence of characteristic amino acid peaks in the ToF-SIMS data. Angle-resolved XPS data show that the protein is inserted into the bilayer, rather than adsorbed on the bilayer surface. This is the first study to demonstrate the use of ultra-high-vacuum techniques for structural studies of supported proteolipid bilayers.

  20. Kernel based methods for accelerated failure time model with ultra-high dimensional data

    Directory of Open Access Journals (Sweden)

    Jiang Feng

    2010-12-01

    Full Text Available Abstract Background Most genomic data have ultra-high dimensions with more than 10,000 genes (probes. Regularization methods with L1 and Lp penalty have been extensively studied in survival analysis with high-dimensional genomic data. However, when the sample size n ≪ m (the number of genes, directly identifying a small subset of genes from ultra-high (m > 10, 000 dimensional data is time-consuming and not computationally efficient. In current microarray analysis, what people really do is select a couple of thousands (or hundreds of genes using univariate analysis or statistical tests, and then apply the LASSO-type penalty to further reduce the number of disease associated genes. This two-step procedure may introduce bias and inaccuracy and lead us to miss biologically important genes. Results The accelerated failure time (AFT model is a linear regression model and a useful alternative to the Cox model for survival analysis. In this paper, we propose a nonlinear kernel based AFT model and an efficient variable selection method with adaptive kernel ridge regression. Our proposed variable selection method is based on the kernel matrix and dual problem with a much smaller n × n matrix. It is very efficient when the number of unknown variables (genes is much larger than the number of samples. Moreover, the primal variables are explicitly updated and the sparsity in the solution is exploited. Conclusions Our proposed methods can simultaneously identify survival associated prognostic factors and predict survival outcomes with ultra-high dimensional genomic data. We have demonstrated the performance of our methods with both simulation and real data. The proposed method performs superbly with limited computational studies.

  1. Convergence of Sample Eigenvalues, Eigenvectors, and Principal Component Scores for Ultra-High Dimensional Data.

    Science.gov (United States)

    Lee, Seunggeun; Zou, Fei; Wright, Fred A

    2014-06-01

    The development of high-throughput biomedical technologies has led to increased interest in the analysis of high-dimensional data where the number of features is much larger than the sample size. In this paper, we investigate principal component analysis under the ultra-high dimensional regime, where both the number of features and the sample size increase as the ratio of the two quantities also increases. We bridge the existing results from the finite and the high-dimension low sample size regimes, embedding the two regimes in a more general framework. We also numerically demonstrate the universal application of the results from the finite regime.

  2. Laser-Machined Ultra-High-Q Microrod Resonators for Nonlinear Optics

    CERN Document Server

    Del'Haye, Pascal; Papp, Scott B

    2013-01-01

    Optical whispering-gallery microresonators are useful tools in microphotonics, and nonlinear optics at very low threshold powers. Here, we present details about the fabrication of ultra-high-Q whispering-gallery-mode resonators made by CO2-laser lathe machining of fused-quartz rods. The resonators can be fabricated in less than one minute and the obtained optical quality factors exceed Q = 10^9. Demonstrated resonator diameters are in the range between 170 {\\mu}m and 8 mm (free spectral ranges between 390 GHz and 8 GHz). Using these microresonators, a variety of optical nonlinearities are observed, including Raman scattering, Brillouin scattering and four-wave mixing.

  3. World′s first telepathology experiments employing WINDS ultra-high-speed internet satellite, nicknamed "KIZUNA"

    Directory of Open Access Journals (Sweden)

    Takashi Sawai

    2013-01-01

    Full Text Available Background: Recent advances in information technology have allowed the development of a telepathology system involving high-speed transfer of high-volume histological figures via fiber optic landlines. However, at present there are geographical limits to landlines. The Japan Aerospace Exploration Agency (JAXA has developed the "Kizuna" ultra-high speed internet satellite and has pursued its various applications. In this study we experimented with telepathology in collaboration with JAXA using Kizuna. To measure the functionality of the Wideband InterNet working engineering test and Demonstration Satellite (WINDS ultra-high speed internet satellite in remote pathological diagnosis and consultation, we examined the adequate data transfer speed and stability to conduct telepathology (both diagnosis and conferencing with functionality, and ease similar or equal to telepathology using fiber-optic landlines. Materials and Methods: We performed experiments for 2 years. In year 1, we tested the usability of the WINDS for telepathology with real-time video and virtual slide systems. These are state-of-the-art technologies requiring massive volumes of data transfer. In year 2, we tested the usability of the WINDS for three-way teleconferencing with virtual slides. Facilities in Iwate (northern Japan, Tokyo, and Okinawa were connected via the WINDS and voice conferenced while remotely examining and manipulating virtual slides. Results: Network function parameters measured using ping and Iperf were within acceptable limits. However; stage movement, zoom, and conversation suffered a lag of approximately 0.8 s when using real-time video, and a delay of 60-90 s was experienced when accessing the first virtual slide in a session. No significant lag or inconvenience was experienced during diagnosis and conferencing, and the results were satisfactory. Our hypothesis was confirmed for both remote diagnosis using real-time video and virtual slide systems, and also

  4. Microstructure-Fibre-Based Optical Parametric Amplification in Telecom Band with Ultra-High Gain Slope

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; XIAO Li; ZHANG Lei; HUANG Yi-Dong; PENG Jiang-De

    2006-01-01

    @@ We report a microstructure-fibre-based parametric amplification experiment in telecom band with ultra-high gain slope. A peak on-off gain of 52.3 dB is achieved using 25 m high nonlinear microstructure fibre (MF) and only 5.3 W pump power. The parametric gain slope is up to 580dBW-1 km-1. From the experimental data, the linear coefficient of the MF is estimated to be about 66. 7 W-1 km-1. The experiment shows the great potential of MFs in practical fibre parametric amplifiers.

  5. Mechanism of Austenite Evolution During Deformation of Ultra-High Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-lan; SUN Xin-jun; DONG Han

    2008-01-01

    The mechanism of transformation of austenite to cementite and pearlite during the deformation of ultra-high carbon steel was discussed. The results indicate that the pearlite and cementite can be induced by deformation be-tween Acm to Arcm. The transformation during deformation is still considered as a diffusion-controlled process. With the increase of time and reduction, the pearlite fraction increased. At the beginning of the transformation, the pearli- te was lamelliform. When the rate of reduction was increased to 70%, some of the induced lamellar pearlite was bro-ken up under deformation.

  6. The evaluation of different environments in ultra-high frequency induction sintered powder metal compacts

    Energy Technology Data Exchange (ETDEWEB)

    Cavdar, P. S.; Cavdar, U.

    2015-03-30

    The application of the iron based Powder Metal (PM) compacts in Ultra-High Frequency Induction Sintering (UHFIS) was reviewed for different environments. The three different environments: atmosphere, argon and vacuum were applied to the PM compacts. Iron based PM compacts were sintered at 1120 degree centigrade for a total of 550 seconds by using induction sintering machines with 2.8 kW power and 900 kHz frequency. Micro structural properties, densities, roughness and micro hardness values were obtained for all environments. The results were compared with each other. (Author)

  7. Microscopic description of rotation: From ground states to the extremes of ultra-high spin

    CERN Document Server

    Afanasjev, A V

    2013-01-01

    Recent progress in the microscopic description of rotational properties within covariant density functional theory (CDFT) is presented. It is shown that it provides an accurate description of rotational bands both in the paired regime at low spin and in the unpaired regime at ultra-high spins. The predictive power of CDFT is verified by comparing the CDFT predictions for band crossing features in the $A\\geq 242$ actinides with new experimental data. In addition, possible role of the Coulomb antipairing effect for proton pairing is discussed.

  8. Systems and methods for advanced ultra-high-performance InP solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wanlass, Mark

    2017-03-07

    Systems and Methods for Advanced Ultra-High-Performance InP Solar Cells are provided. In one embodiment, an InP photovoltaic device comprises: a p-n junction absorber layer comprising at least one InP layer; a front surface confinement layer; and a back surface confinement layer; wherein either the front surface confinement layer or the back surface confinement layer forms part of a High-Low (HL) doping architecture; and wherein either the front surface confinement layer or the back surface confinement layer forms part of a heterointerface system architecture.

  9. Exploratory visualization of astronomical data on ultra-high-resolution wall displays

    Science.gov (United States)

    Pietriga, Emmanuel; del Campo, Fernando; Ibsen, Amanda; Primet, Romain; Appert, Caroline; Chapuis, Olivier; Hempel, Maren; Muñoz, Roberto; Eyheramendy, Susana; Jordan, Andres; Dole, Hervé

    2016-07-01

    Ultra-high-resolution wall displays feature a very high pixel density over a large physical surface, which makes them well-suited to the collaborative, exploratory visualization of large datasets. We introduce FITS-OW, an application designed for such wall displays, that enables astronomers to navigate in large collections of FITS images, query astronomical databases, and display detailed, complementary data and documents about multiple sources simultaneously. We describe how astronomers interact with their data using both the wall's touchsensitive surface and handheld devices. We also report on the technical challenges we addressed in terms of distributed graphics rendering and data sharing over the computer clusters that drive wall displays.

  10. Widespread inflammation in CLIPPERS syndrome indicated by autopsy and ultra-high-field 7T MRI

    OpenAIRE

    Blaabjerg, M.; Ruprecht, K.; Sinnecker, T.; Kondziella, D.; Niendorf, T; Kerrn-Jespersen, B.M.; Lindelof, M.; Lassmann, H; Kristensen, B.W.; Paul, F; Illes, Z.

    2016-01-01

    OBJECTIVE: To examine if there is widespread inflammation in the brain of patients with chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome by using histology and ultra-high-field MRI at 7.0T. METHODS: We performed a detailed neuropathologic examination in 4 cases, including 1 autopsy case, and studied 2 additional patients by MRI at 7.0T to examine (1) extension of inflammation to areas appearing normal on 3.0T MRI, (2) potential ...

  11. Assessment of the State of the Art of Ultra High Temperature Ceramics

    Science.gov (United States)

    Johnson, Sylvia; Gasch, Matt; Stackpoole, Mairead

    2009-01-01

    Ultra High Temperature Ceramics (UHTCs) are a family of materials that includes the borides, carbides and nitrides of hafnium-, zirconium- and titanium-based systems. UHTCs are famous for possessing some of the highest melting points of known materials. In addition, they are very hard, have good wear resistance, mechanical strength, and relatively high thermal conductivities (compared to other ceramic materials). Because of these attributes, UHTCs are ideal for thermal protection systems, especially those that require chemical and structural stability at extremely high operating temperatures. UHTCs have the potential to revolutionize the aerospace industry by enabling the development of sharp hypersonic vehicles or atmospheric entry probes capable of the most extreme entry conditions.

  12. O-Ring sealing arrangements for ultra-high vacuum systems

    Science.gov (United States)

    Kim, Chang-Kyo; Flaherty, Robert

    1981-01-01

    An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

  13. Gas and RRR Distribution in High Purity Niobium EB Welded in Ultra-High Vacuum.

    OpenAIRE

    Anakhov, S.; Singer, X.; W. Singer; Wen, H.

    2006-01-01

    Electron beam (EB) welding in UHV (ultra-high vacuum, 10(-5) divided by 10(-8) mbar) is applied in the standard fabrication of high gradient niobium superconducting radio frequency (SRF) cavities of TESLA design. The quality of EB welding is critical for cavity performance. Experimental data of gas content (H-2, O-2, N-2) and RRR (residual resistivity ratio) measurements in niobium (Nb) welding seams are presented. EB welding in UHV conditions allow to preserve low gas content (1 divided by 3...

  14. Enabling ultra high precision on hard steels using surface defect machining

    OpenAIRE

    2014-01-01

    This paper is an extension to an idea coined during the 13th EUSPEN Conference (P6.23) named "surface defect machining" (SDM). The objective of this work was to demonstrate how a conventional CNC turret lathe can be used to obtain ultra high precision machined surface finish on hard steels without recourse to a sophisticated ultra precision machine tool. An AISI 4340 hard steel (69 HRC) workpiece was machined using a CBN cutting tool with and without SDM. Post-machining measurements by a Form...

  15. New Spheroidizing Technique of Ultra-High Carbon Steel With Aluminum Addition

    Institute of Scientific and Technical Information of China (English)

    LI Hong-juan; WANG Bao-qi; SONG Xiao-yan; GUO Su-zhen; GU Nan-ju

    2006-01-01

    A new spheroidizing process of ultra-high carbon steel (UHCS) containing C 1.55%, Cr 1.45%, and Al 1.5% in mass percent has been proposed. The effect of processing parameters on the microstructure was analyzed. The UHCS produced by this new process has a microstructure with recrystallized ferrite matrix and fine and uniform carbide particles. After this spheroidizing, the UHCS exhibits good mechanical properties at ambient temperature, for example σb=1 100 MPa, σs=915 MPa, δ=8% and high ratio of σs/σb.

  16. Ultra high frequency-electromagnetic field irradiation during pregnancy leads to an increase in erythrocytes micronuclei incidence in rat offspring.

    Science.gov (United States)

    Ferreira, Amâncio Romanelli; Knakievicz, Tanise; Pasquali, Matheus Augusto de Bittencourt; Gelain, Daniel Pens; Dal-Pizzol, Felipe; Fernández, Claudio Enrique Rodriguez; de Salles, Alvaro Augusto de Almeida; Ferreira, Henrique Bunselmeyer; Moreira, José Cláudio Fonseca

    2006-12-03

    Mobile telephones and their base stations are an important ultra high frequency-electromagnetic field (UHF-EMF) source and their utilization is increasing all over the world. Epidemiological studies suggested that low energy UHF-EMF emitted from a cellular telephone may cause biological effects, such as DNA damage and changes on oxidative metabolism. An in vivo mammalian cytogenetic test, the micronucleus (MN) assay, was used to investigate the occurrence of chromosomal damage in erythrocytes from rat offspring exposed to a non-thermal UHF-EMF from a cellular phone during their embryogenesis; the irradiated group showed a significant increase in MN occurrence. In order to investigate if UHF-EMF could also alter oxidative parameters in the peripheral blood and in the liver - an important hematopoietic tissue in rat embryos and newborns - we also measured the activity of antioxidant enzymes, quantified total sulfhydryl content, protein carbonyl groups, thiobarbituric acid-reactive species and total non-enzymatic antioxidant defense. No significant differences were found in any oxidative parameter of offspring blood and liver. The average number of pups in each litter has also not been significantly altered. Our results suggest that, under our experimental conditions, UHF-EMF is able to induce a genotoxic response in hematopoietic tissue during the embryogenesis through an unknown mechanism.

  17. Design and analysis of a direct-drive wind power generator with ultra-high torque density

    Science.gov (United States)

    Jian, Linni; Shi, Yujun; Wei, Jin; Zheng, Yanchong

    2015-05-01

    In order to get rid of the nuisances caused by mechanical gearboxes, generators with low rated speed, which can be directly connected to wind turbines, are attracting increasing attention. The purpose of this paper is to propose a new direct-drive wind power generator (DWPG), which can offer ultra-high torque density. First, magnetic gear (MG) is integrated to achieve non-contact torque transmission and speed variation. Second, armature windings are engaged to achieve electromechanical energy conversion. Interior permanent magnet (PM) design on the inner rotor is adopted to boost the torque transmission capability of the integrated MG. Nevertheless, due to lack of back iron on the stator, the proposed generator does not exhibit prominent salient feature, which usually exists in traditional interior PM (IPM) machines. This makes it with good controllability and high power factor as the surface-mounted permanent magnet machines. The performance is analyzed using finite element method. Investigation on the magnetic field harmonics demonstrates that the permanent-magnetic torque offered by the MG can work together with the electromagnetic torque offered by the armature windings to balance the driving torque captured by the wind turbine. This allows the proposed generator having the potential to offer even higher torque density than its integrated MG.

  18. Concrete Materials with Ultra-High Damage Resistance and Self- Sensing Capacity for Extended Nuclear Fuel Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mo [Univ. of California, Irvine, CA (United States); Nakshatrala, Kalyana [Univ. of Houston, TX (United States); William, Kasper [Univ. of Houston, TX (United States); Xi, Yungping [Univ. of Colorado, Boulder, CO (United States)

    2017-02-08

    The objective of this project is to develop a new class of multifunctional concrete materials (MSCs) for extended spent nuclear fuel (SNF) storage systems, which combine ultra-high damage resistance through strain-hardening behavior with distributed multi-dimensional damage self-sensing capacity. The beauty of multifunctional concrete materials is two-fold: First, it serves as a major material component for the SNF pool, dry cask shielding and foundation pad with greatly improved resistance to cracking, reinforcement corrosion, and other common deterioration mechanisms under service conditions, and prevention from fracture failure under extreme events (e.g. impact, earthquake). This will be achieved by designing multiple levels of protection mechanisms into the material (i.e., ultrahigh ductility that provides thousands of times greater fracture energy than concrete and normal fiber reinforced concrete; intrinsic cracking control, electrochemical properties modification, reduced chemical and radionuclide transport properties, and crack-healing properties). Second, it offers capacity for distributed and direct sensing of cracking, strain, and corrosion wherever the material is located. This will be achieved by establishing the changes in electrical properties due to mechanical and electrochemical stimulus. The project will combine nano-, micro- and composite technologies, computational mechanics, durability characterization, and structural health monitoring methods, to realize new MSCs for very long-term (greater than 120 years) SNF storage systems.

  19. Discharging a Li-S battery with ultra-high sulphur content cathode using a redox mediator

    Science.gov (United States)

    Kim, Kwi Ryong; Lee, Kug-Seung; Ahn, Chi-Yeong; Yu, Seung-Ho; Sung, Yung-Eun

    2016-08-01

    Lithium-sulphur batteries are under intense research due to the high specific capacity and low cost. However, several problems limit their commercialization. One of them is the insulating nature of sulphur, which necessitates a large amount of conductive agent and binder in the cathode, reducing the effective sulphur load as well as the energy density. Here we introduce a redox mediator, cobaltocene, which acts as an electron transfer agent between the conductive surface and the polysulphides in the electrolyte. We confirmed that cobaltocene could effectively convert polysulphides to Li2S using scanning electron microscope, X-ray absorption near-edge structure and in-situ X-ray diffraction studies. This redox mediator enabled excellent electrochemical performance in a cathode with ultra-high sulphur content (80 wt%). It delivered 400 mAh g-1cathode capacity after 50 cycles, which is equivalent to 800 mAh g-1S in a typical cathode with 50 wt% sulphur. Furthermore, the volumetric capacity was also dramatically improved.

  20. Hot deformation mechanism and microstructure evolution of an ultra-high nitrogen austenitic steel containing Nb and V

    Institute of Scientific and Technical Information of China (English)

    Rong-hua Zhang; Ze-an Zhou; Ming-wei Guo; Jian-jun Qi; Shu-hua Sun; Wan-tang Fu

    2015-01-01

    The flow curves of an ultra-high nitrogen austenitic steel containing niobium (Nb) and vanadium (V) were obtained by hot com-pression deformation at temperatures ranging from 1000℃ to 1200℃ and strain rates ranging from 0.001 s?1 to 10 s?1. The mechanical be-havior during hot deformation was discussed on the basis of flow curves and hot processing maps. The microstructures were analyzed via scanning electron microscopy and electron backscatter diffraction. The relationship between deformation conditions and grain size after dy-namic recrystallization was obtained. The results show that the flow stress and peak strain both increase with decreasing temperature and in-creasing strain rate. The hot deformation activation energy is approximately 631 kJ/mol, and a hot deformation equation is proposed. (Nb,V)N precipitates with either round, square, or irregular shapes are observed at the grain boundaries and in the matrix after deformation. According to the discussion, the hot working should be processed in the temperature range of 1050℃ to 1150℃ and in the strain rate range of 0.01 to 1 s?1.

  1. Microfluidic pumping through miniaturized channels driven by ultra-high frequency surface acoustic waves

    Energy Technology Data Exchange (ETDEWEB)

    Shilton, Richie J., E-mail: richard.shilton@iit.it [Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy); Travagliati, Marco [Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy); NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa (Italy); Beltram, Fabio [NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa (Italy); Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy); Cecchini, Marco, E-mail: marco.cecchini@nano.cnr.it [NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa (Italy)

    2014-08-18

    Surface acoustic waves (SAWs) are an effective means to pump fluids through microchannel arrays within fully portable systems. The SAW-driven acoustic counterflow pumping process relies on a cascade phenomenon consisting of SAW transmission through the microchannel, SAW-driven fluid atomization, and subsequent coalescence. Here, we investigate miniaturization of device design, and study both SAW transmission through microchannels and the onset of SAW-driven atomization up to the ultra-high-frequency regime. Within the frequency range from 47.8 MHz to 754 MHz, we show that the acoustic power required to initiate SAW atomization remains constant, while transmission through microchannels is most effective when the channel widths w ≳ 10 λ, where λ is the SAW wavelength. By exploiting the enhanced SAW transmission through narrower channels at ultra-high frequencies, we discuss the relevant frequency-dependent length scales and demonstrate the scaling down of internal flow patterns and discuss their impact on device miniaturization strategies.

  2. Gas-Enhanced Ultra-High Shear Mixing: A Concept and Applications

    Science.gov (United States)

    Czerwinski, Frank; Birsan, Gabriel

    2017-04-01

    The processes of mixing, homogenizing, and deagglomeration are of paramount importance in many industries for modifying properties of liquids or liquid-based dispersions at room temperature and treatment of molten or semi-molten alloys at high temperatures, prior to their solidification. To implement treatments, a variety of technologies based on mechanical, electromagnetic, and ultrasonic principles are used commercially or tested at the laboratory scale. In a large number of techniques, especially those tailored toward metallurgical applications, the vital role is played by cavitation, generation of gas bubbles, and their interaction with the melt. This paper describes a novel concept exploring an integration of gas injection into the shear zone with ultra-high shear mixing. As revealed via experiments with a prototype of the cylindrical rotor-stator apparatus and transparent media, gases injected radially through the high-speed rotor generate highly refined bubbles of high concentration directly in the shear zone of the mixer. It is believed that an interaction of large volume of fine gas bubbles with the liquid, superimposed on ultra-high shear, will enhance mixing capabilities and cause superior refining and homogenizing of the liquids or solid-liquid slurries, thus allowing their effective property modification.

  3. Concept of modular flexure-based mechanisms for ultra-high precision robot design

    Directory of Open Access Journals (Sweden)

    M. Richard

    2011-05-01

    Full Text Available This paper introduces a new concept of modular flexure-based mechanisms to design industrial ultra-high precision robots, which aims at significantly reducing both the complexity of their design and their development time. This modular concept can be considered as a robotic Lego, where a finite number of building bricks is used to quickly build a high-precision robot. The core of the concept is the transformation of a 3-D design problem into several 2-D ones, which are simpler and well-mastered. This paper will first briefly present the theoretical bases of this methodology and the requirements of both types of building bricks: the active and the passive bricks. The section dedicated to the design of the active bricks will detail the current research directions, mainly the maximisation of the strokes and the development of an actuation sub-brick. As for the passive bricks, some examples will be presented, and a discussion regarding the establishment of a mechanical solution catalogue will conclude the section. Last, this modular concept will be illustrated with a practical example, consisting in the design of a 5-degree of freedom ultra-high precision robot.

  4. Quality of Experience for Large Ultra-High-Resolution Tiled Displays with Synchronization Mismatch

    Directory of Open Access Journals (Sweden)

    Deshpande Sachin

    2011-01-01

    Full Text Available This paper relates to quality of experience when viewing images, video, or other content on large ultra-high-resolution displays made from individual display tiles. We define experiments to measure vernier acuity caused by synchronization mismatch for moving images. The experiments are used to obtain synchronization mismatch acuity threshold as a function of object velocity and as a function of occlusion or gap width. Our main motivation for measuring the synchronization mismatch vernier acuity is its relevance in the application of tiled display systems, which create a single contiguous image using individual discrete panels arranged in a matrix with each panel utilizing a distributed synchronization algorithm to display parts of the overall image. We also propose a subjective assessment method for perception evaluation of synchronization mismatch for large ultra-high-resolution tiled displays. For this, we design a synchronization mismatch measurement test video set for various tile configurations for various interpanel synchronization mismatch values. The proposed method for synchronization mismatch perception can evaluate tiled displays with or without tile bezels. The results from this work can help during design of low-cost tiled display systems, which utilize distributed synchronization mechanisms for a contiguous or bezeled image display.

  5. Improvement of performance of ultra-high performance concrete based composite material added with nano materials

    Directory of Open Access Journals (Sweden)

    Pang Jinchang

    2016-03-01

    Full Text Available Ultra-high performance concrete (UHPC, a kind of composite material characterized by ultra high strength, high toughness and high durability. It has a wide application prospect in engineering practice. But there are some defects in concrete. How to improve strength and toughness of UHPC remains to be the target of researchers. To obtain UHPC with better performance, this study introduced nano-SiO2 and nano-CaCO3 into UHPC. Moreover, hydration heat analysis, X-Ray Diffraction (XRD, mercury intrusion porosimetry (MIP and nanoindentation tests were used to explore hydration process and microstructure. Double-doped nanomaterials can further enhance various mechanical performances of materials. Nano-SiO2 can promote early progress of cement hydration due to its high reaction activity and C-S-H gel generates when it reacts with cement hydration product Ca(OH2. Nano-CaCO3 mainly plays the role of crystal nucleus effect and filling effect. Under the combined action of the two, the composite structure is denser, which provides a way to improve the performance of UHPC in practical engineering.

  6. Approaches for springback reduction when forming ultra high-strength sheet metals

    Science.gov (United States)

    Radonjic, R.; Liewald, M.

    2016-11-01

    Nowadays, the automotive industry is challenged constantly by increasing environmental regulations and the continuous enhancement of standards with regard to passenger's safety (NCAP, Part 1). In order to fulfil the aforementioned requirements, the use of ultra high-strength steels in research and industrial applications is of high interest. When forming such materials, the main problem results from the large amount of springback which occurs after the release of the part. This paper shows the applicability of several approaches for the reduction of springback amount by forming of one hat channel shaped component. A novel approach for springack reduction which is based on forming with an alternating blank draw-in is presented as well. In this investigation an ultra high-strength steel of the grade DP 980 was used. The part's measurements were taken at significant cross-sections in order to provide a qualitative comparison between the reference geometry and the part's released shape. The obtained results were analysed and used in order to quantify the success of particular approaches for springback reduction. When taking a curved hat channel shaped component as an example, the results achieved in the investigations showed that it is possible to reduce part shape deviations significantly when using DP 980 as workpiece material.

  7. Ultra-high vacuum compatible induction-heated rod casting furnace

    CERN Document Server

    Bauer, Andreas; Münzer, Wolfgang; Regnat, Alexander; Benka, Georg; Meven, Martin; Pedersen, Björn; Pfleiderer, Christian

    2016-01-01

    We report the design of a radio-frequency induction-heated rod casting furnace that permits the preparation of polycrystalline ingots of intermetallic compounds under ultra-high vacuum compatible conditions. The central part of the system is a bespoke water-cooled Hukin crucible supporting a casting mold. Depending on the choice of mold, typical rods have a diameter between 6 mm and 10 mm and a length up to 90 mm, suitable for single-crystal growth by means of float-zoning. The setup is all-metal sealed and may be baked out. We find that the resulting ultra-high vacuum represents an important precondition for processing compounds with high vapor pressures under a high-purity argon atmosphere up to 3 bar. Using the rod casting furnace, we succeeded to prepare large high-quality single crystals of two half-Heusler compounds, namely the itinerant antiferromagnet CuMnSb and the half-metallic ferromagnet NiMnSb.

  8. Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Luisa Ciobanu

    Full Text Available During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T(2*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7T and 17.2T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine. We showed that the brain/vessels contrast in T(2*-weighted images at 17.2T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation.

  9. Ultra-high-throughput Production of III-V/Si Wafer for Electronic and Photonic Applications.

    Science.gov (United States)

    Geum, Dae-Myeong; Park, Min-Su; Lim, Ju Young; Yang, Hyun-Duk; Song, Jin Dong; Kim, Chang Zoo; Yoon, Euijoon; Kim, SangHyeon; Choi, Won Jun

    2016-02-11

    Si-based integrated circuits have been intensively developed over the past several decades through ultimate device scaling. However, the Si technology has reached the physical limitations of the scaling. These limitations have fuelled the search for alternative active materials (for transistors) and the introduction of optical interconnects (called "Si photonics"). A series of attempts to circumvent the Si technology limits are based on the use of III-V compound semiconductor due to their superior benefits, such as high electron mobility and direct bandgap. To use their physical properties on a Si platform, the formation of high-quality III-V films on the Si (III-V/Si) is the basic technology ; however, implementing this technology using a high-throughput process is not easy. Here, we report new concepts for an ultra-high-throughput heterogeneous integration of high-quality III-V films on the Si using the wafer bonding and epitaxial lift off (ELO) technique. We describe the ultra-fast ELO and also the re-use of the III-V donor wafer after III-V/Si formation. These approaches provide an ultra-high-throughput fabrication of III-V/Si substrates with a high-quality film, which leads to a dramatic cost reduction. As proof-of-concept devices, this paper demonstrates GaAs-based high electron mobility transistors (HEMTs), solar cells, and hetero-junction phototransistors on Si substrates.

  10. Enhanced antioxidant and antityrosinase activities of longan fruit pericarp by ultra-high-pressure-assisted extraction.

    Science.gov (United States)

    Prasad, K Nagendra; Yang, Bao; Shi, John; Yu, Chunyan; Zhao, Mouming; Xue, Sophia; Jiang, Yueming

    2010-01-20

    The health benefits of fruits acting against chronic diseases are ascribed to their antioxidant activities which are mainly responsible due to the presence of phenolic compounds. The use of ultra-high-pressure-assisted extraction (UHPE) has shown great advantages for the extraction of these phenolic compounds from longan fruit pericarp (LFP). Studies were carried out to investigate the effects of UHPE at pressures of 200, 300, 400 and 500 MPa on total phenolic contents, extraction yield, antioxidant and antityrosinase activities from LFP. The antioxidant activities of these extracts were analyzed, using various antioxidant models like 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, total antioxidant capacity and superoxide anion radical scavenging activity. Extract from ultra-high-pressure-assisted extraction at 500MPa (UHPE-500) showed the highest antioxidant activities of all the tested models. In addition, it also showed moderate tyrosinase inhibitory activity. Three phenolic acids, namely gallic acid, ellagic acid, and corilagin were identified and quantified by HPLC. Corilagin content was the highest compared to other phenolic acids identified. UHPE-500 obtained the higher phenolic acid contents compared to other high pressure processing and conventional extractions (CE). Compared with CE, UHPE-500 exhibited good extraction effectiveness in terms of higher extraction yields with high phenolic contents and also with higher antioxidant and antityrosinase activities.

  11. 信息动态%Size Effect on Strength of Ultra-high Strength Concrete RPC

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Reactive Powder Concrete (RPC)is a new kind of ultra-high strength cement based composite with excellent mechanics performance and durability. In order to make RPC used in structural engineering effectively,size effect on strength of the ultra high strength concrete RPC specimen is experimental studied and the mechanism is analyzed in this paper. Test results show that if the 4 cm cube compressive strength is the control strength,conversion coefficients of 10 em cube compressive strength at 150 MPa and 200 MPa grade are 0.81 and 0.76 respectively; conversion coefficients of 10 cm× 10 cm× 30 cm prism compressive strength at 150 MPa and 200 MPa grade are 0.71 and 0. 63 respectively; the size effect conversion coefficient tends to decrease with the increase of control strength, the larger the specimen size, the lower the compressive strength. RPC is a typical brittle material. It extends instability quickly after cracking;damage concentrated in the local area,and therefore appears higher size effect.

  12. Gas-Enhanced Ultra-High Shear Mixing: A Concept and Applications

    Science.gov (United States)

    Czerwinski, Frank; Birsan, Gabriel

    2016-12-01

    The processes of mixing, homogenizing, and deagglomeration are of paramount importance in many industries for modifying properties of liquids or liquid-based dispersions at room temperature and treatment of molten or semi-molten alloys at high temperatures, prior to their solidification. To implement treatments, a variety of technologies based on mechanical, electromagnetic, and ultrasonic principles are used commercially or tested at the laboratory scale. In a large number of techniques, especially those tailored toward metallurgical applications, the vital role is played by cavitation, generation of gas bubbles, and their interaction with the melt. This paper describes a novel concept exploring an integration of gas injection into the shear zone with ultra-high shear mixing. As revealed via experiments with a prototype of the cylindrical rotor-stator apparatus and transparent media, gases injected radially through the high-speed rotor generate highly refined bubbles of high concentration directly in the shear zone of the mixer. It is believed that an interaction of large volume of fine gas bubbles with the liquid, superimposed on ultra-high shear, will enhance mixing capabilities and cause superior refining and homogenizing of the liquids or solid-liquid slurries, thus allowing their effective property modification.

  13. Simulation about hot stamping of ultra-high strength steel on the basis of lightweight technology

    Institute of Scientific and Technical Information of China (English)

    Liu Qiang; Ma Fangwu; Wang Xiaona; Yao Zaiqi; Song Wei; Zhao Fuquan; Ma Mingttu; Song Leifeng

    2012-01-01

    With the development of automobile lightweight, it is very necessary to apply the ultra-high strength steel parts manufactured by hot stamping, which offers the possibility to reduce the weight of automobiles and maintain the safety requirement. In order to complete hot stamping, it is important to design the structure of parts reasonably, which is related with reasonable matching of strength. The objective of this paper is to guide the design of parts manufactured by hot stamping and find the forming technical requirements of vehicle performance. Through experiments, the paper obtains the stress and strain curves at different deformation temperatures and strain rates. Based on experimental data, the constitutive relationship model is established which can reflect the deformation capacity of ultra-high strength steel during the process of hot stamping. Combined with finite element simulation results of hot stamping by commercial soft- ware AUTOFORM, transfer path of load and matching law of strength, the paper determines the design criteria and forming technical requirements of parts manufactured by hot stamping. At the same time, the impact performance of front cross member internal plate is taken into consideration.

  14. Aspects of ultra-high-precision diamond machining of RSA 443 optical aluminium

    Science.gov (United States)

    Mkoko, Z.; Abou-El-Hossein, K.

    2015-08-01

    Optical aluminium alloys such as 6061-T6 are traditionally used in ultra-high precision manufacturing for making optical mirrors for aerospace and other applications. However, the optics industry has recently witnessed the development of more advanced optical aluminium grades that are capable of addressing some of the issues encountered when turning with single-point natural monocrystalline diamond cutters. The advent of rapidly solidified aluminium (RSA) grades has generally opened up new possibilities for ultra-high precision manufacturing of optical components. In this study, experiments were conducted with single-point diamond cutters on rapidly solidified aluminium RSA 443 material. The objective of this study is to observe the effects of depth of cut and feed rate at a fixed rotational speed on the tool wear rate and resulting surface roughness of diamond turned specimens. This is done to gain further understanding of the rate of wear on the diamond cutters versus the surface texture generated on the RSA 443 material. The diamond machining experiments yielded machined surfaces which are less reflective but with consistent surface roughness values. Cutting tools were observed for wear through scanning microscopy; relatively low wear pattern was evident on the diamond tool edge. The highest tool wear were obtained at higher depth of cut and increased feed rate.

  15. Dynamic tensile behavior of AZ31B magnesium alloy at ultra-high strain rates

    Directory of Open Access Journals (Sweden)

    Geng Changjian

    2015-04-01

    Full Text Available The samples having {0001} parallel to extruding direction (ED present a typical true stress–true strain curve with concave-down shape under tension at low strain rate. Ultra-rapid tensile tests were conducted at room temperature on a textured AZ31B magnesium alloy. The dynamic tensile behavior was investigated. The results show that at ultra-high strain rates of 1.93 × 102 s−1 and 1.70 × 103 s−1, the alloy behaves with a linear stress–strain response in most strain range and exhibits a brittle fracture. In this case, {10-12}  extension twinning is basic deformation mode. The brittleness is due to the macroscopic viscosity at ultra-high strain rate, for which the external critical shear stress rapidly gets high to result in a cleavage fracture before large amounts of dislocations are activated. Because {10-12} tension twinning, {10-11} compressive twinning, basal slip, prismatic slip and pyramidal slip have different critical shear stresses (CRSS, their contributions to the degree of deformation are very differential. In addition, Schmid factor plays an important role in the activity of various deformation modes and it is the key factor for the samples with different strain rates exhibit various mechanical behavior under dynamic tensile loading.

  16. Ultra High Energy Cosmic Ray, Neutrino, and Photon Propagation and the Multi-Messenger Approach

    CERN Document Server

    Taylor, Andrew M; Castillo-Ruiz, Edith

    2009-01-01

    The propagation of UHECR nuclei for A=1 (protons) to A=56 (iron) from cosmological sources through extragalactic space is discussed in the first lecture. This is followed in the second and third lectures by a consideration of the generation and propagation of secondary particles produced via the UHECR loss interactions. In the second lecture we focus on the generation of the diffuse cosmogenic UHE-neutrino flux. In the third lecture we investigate the arriving flux of UHE-photon flux at Earth. In the final lecture the results of the previous lectures are put together in order to provide new insights into UHECR sources. The first of these providing a means with which to investigate the local population of UHECR sources through the measurement of the UHECR spectrum and their photon fraction at Earth. The second of these providing contraints on the UHECR source radiation fields through the possible observation at Earth of UHECR nuclei.

  17. Relation between hadronic interactions and ultra-high energy extensive air showers

    Directory of Open Access Journals (Sweden)

    Ulrich Ralf

    2015-01-01

    Full Text Available The simulation of hadronic interactions is of fundamental importance for the analysis of extensive air showers. The details of the relation between the measurement of hadronic interactions at accelerators and the impact on the air shower development is very difficult to evaluate. Several possibilities to study this relation are presented here.

  18. Development of sensors for the acoustic detection of ultra high energy neutrinos in the deep sea

    Energy Technology Data Exchange (ETDEWEB)

    Naumann, C.L.

    2007-09-17

    In addition to the optical detection system used by the ANTARES detector, a proposal was made to include an acoustic system consisting of several modified ANTARES storeys to investigate the feasibility of building and operating an acoustic particle detection system in the deep sea and at the same time perform an extensive study of the acoustic properties of the deep sea environment. The directional characteristics of the sensors and their placement within the ANTARES detector had to be optimised for the study of the correlation properties of the acoustic noise at different length scales - from below a metre to above 100 metres. The so-called 'equivalent circuit diagram (=ECD) model' - was applied to predict the acoustic properties of piezo elements, such as sensitivity and intrinsic noise, and was extended by including effects resulting from the geometrical shape of the sensors. A procedure was devised to gain the relevant ECD parameters from electrical impedance measurements of the piezo elements, both free and coupled to a surrounding medium. Based on the findings of this ECD model, intensive design studies were performed with prototype hydrophones using piezo elements as active sensors. The design best suited for the construction of acoustic sensors for ANTARES was determined, and a total of twelve hydrophones were built with a sensitivity of -145 to -140 dB re 1V/{mu}Pa between 5 and 50 kHz and an intrinsic noise power density around -90 dB re 1 V/{radical}(Hz), giving a total noise rms of 7 mV in this frequency range. The hydrophones were pressure tested and calibrated for integration into the ANTARES acoustic system. In addition, three so-called Acoustic Modules, sensors in pressure resistant glass spheres with a sensitive bandwidth of about 80 kHz, were developed and built. The calibration procedure employed during the sensor design studies as well as for the final sensors to be installed in the ANTARES framework is presented, together with exemplary results for both commercial and self-made hydrophones. An absolute calibration procedure employed for the acoustic senders is described, as is a parametrisation for the receiving characteristics of hydrophones independent of their interior design, together with an application of this model for the prediction of signal shapes for reconstruction purposes. (orig.)

  19. Arcsecond-Scale Radio Jets of Ultra-High-Energy Synchrotron Peak BL Lacs (UHBLs)

    Indian Academy of Sciences (India)

    Zhongzu Wu; Shengxu Yang; Minfeng Gu

    2014-09-01

    We present the arcsecond-scale jet structure and related radio properties for a sample of 9 UHBLs selected from Nieppola et al. (2006) with log(peak/Hz) > 20. Our preliminary results show that most of the UHBLs have compact structures, and their core dominance parameters are much larger than FR-I radio galaxies, suggesting that beaming may be prevalent in the jets of these sources.

  20. Particle physics explanations for ultra-high energy cosmic ray events

    Indian Academy of Sciences (India)

    Manuel Dress

    2004-02-01

    The origin of cosmic ray events with $E\\gtrsim 10^{11}$ GeV remains mysterious. In this talk I briefly summarize several proposed particle physics explanations: a breakdown of Lorentz invariance, the `$Z$-burst' scenario, new hadrons with masses of several GeV as primaries, and magnetic monopoles with mass below 1010 GeV as primaries. I then describe in a little more detail the idea that these events are due to the decays of very massive, long-lived exotic particles.

  1. Analysis of the extensive air showers of ultra-high energy

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, Aleksei A. [Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, 31 Lenin Ave., 677980 Yakutsk (Russian Federation)

    2011-03-15

    When we study extensive air showers (EAS), which correlate with pulsars, we had been found showers without a muon component. Here we analyzed the arrival directions of EAS with poor and without a muon component. We find that the arrival directions of these showers correlate with some pulsars which are distributed more isotropy. Among these pulsars with the short period of rotation around their axis are prevailed than it is expected by the catalogue of pulsars. In this connection the data of world arrays are considered.

  2. Invisible Un-removable Field: A Search by Ultra-High Energy Cosmic Rays

    OpenAIRE

    Sato, Humitaka

    2003-01-01

    A Toy model which introduces the different limiting velocities for each particleis discussed: the differentiation of the universal limiting velocity is implemented throgh the coupling with external tensor or vector field, something like Higgs scalar field. GZK cut-off discussion could be altered due to the violation of Lorentz symmetry.

  3. Simulation and Analysis Chain for Acoustic Ultra-high Energy Neutrino Detectors in Water

    CERN Document Server

    Neff, M; Enzenhöfer, A; Graf, K; Hößl, J; Katz, U; Lahmann, R; Sieger, C

    2013-01-01

    Acousticneutrinodetectionisapromisingapproachforlarge-scaleultra-highenergyneutrinodetectorsinwater.In this article, a Monte Carlo simulation chain for acoustic neutrino detection devices in water will be presented. The simulation chain covers the generation of the acoustic pulse produced by a neutrino interaction and its propagation to the sensors within the detector. Currently, ambient and transient noise models for the Mediterranean Sea and simulations of the data acquisition hardware, equivalent to the one used in ANTARES/AMADEUS, are implemented. A pre-selection scheme for neutrino-like signals based on matched filtering is employed, as it is used for on-line filtering. To simulate the whole processing chain for experimental data, signal classification and acoustic source reconstruction algorithms are integrated in an analysis chain. An overview of design and capabilities of the simulation and analysis chain will be presented and preliminary studies will be discussed.

  4. Nuclear Physics Meets the Sources of the Ultra-High Energy Cosmic Rays

    CERN Document Server

    Boncioli, Denise; Winter, Walter

    2016-01-01

    We study the implications of nuclear data and models for cosmic-ray astrophysics, which involves the photodisintegration of nuclei up to iron in astrophysical environments. We demonstrate that data on photo-absorption cross sections are sparse in that mass range by screening nuclear databases, such as EXFOR; these cross sections are needed to compute the photodisintegration rates. We also test the prediction power of models, such as TALYS, and find uncertainties of the order of a factor two. If however the radiation fields are strong enough such that the nuclear cascade in the astrophysical source can develop, we find that differences among different models average out -- unless there is a systematic offset in the interaction model. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions, supported by simulating the entire disintegration chain in a gamma-ray burst. We also point out that a first consistency check may be the measurement of the a...

  5. Advanced Cathode for Ultra-High Energy Li-Ion Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced lithium-ion (Li-ion) batteries are currently under development for Extravehicular Activity Suits, Altair Lunar Landers, and Lunar Mobility Systems. However,...

  6. PREFACE: Rheology and Elasticity Studies at Ultra-High Pressures and Temperatures

    Science.gov (United States)

    Liu, Haozhe; Wenk, Hans-Rudolf; Duffy, Thomas S.

    2006-06-01

    One of the major goals of geophysical research is to understand deformation in the deep Earth. The COMPRES (Consortium for Materials Properties Research in Earth Sciences) workshop on `Rheology and Elasticity Studies at Ultra-High Pressures and Temperatures' was held on 21-23 October 2005 at the Advanced Photon Source, Argonne National Laboratory, organized by Haozhe Liu, Hans-Rudolf Wenk and Thomas S Duffy, and provided an opportunity to assemble more than 50 scientists from six countries. Experts in diamond anvil cell (DAC) design, large-volume high-pressure apparatus and data analysis defined the current state of ultra-high pressure deformation studies and explored initiatives to push the technological frontier. The DAC, when used in radial diffraction geometry, emerges as a powerful tool for investigation of plasticity and elasticity of materials at high pressures. More information regarding this workshop can be found at the website: http://www.hpcat.aps.anl.gov/Hliu/Workshop/Index1.htm. In this special issue of Journal of Physics: Condensed Matter, 17 manuscripts review the state-of-the-art and we hope they will stimulate researchers to participate in this field and take it forward to a new level. A major incentive for high-pressure research has been the need of geophysicists to understand composition, physical properties and deformation in the deep Earth in order to interpret the macroscopically observed seismic anisotropy. In the mantle and core, materials deform largely in a ductile manner at low stresses and strain rates. From observational inferences and experiments at lower pressures, it is considered plausible that deformation occurs in the field of dislocation creep or diffusion creep and deformation mechanisms depend in a complex way on stress, strain rate, pressure, temperature, grain size and hydration state. With novel apparatus such as the rotational Drickamer press or deformation DIA (D-DIA) multianvil apparatus, large volumes (approximately 10

  7. Spray pyrolysis-deposited nanoengineered TiO2 thick films for ultra-high areal and volumetric capacity lithium ion battery applications

    Science.gov (United States)

    Haridas, Anupriya K.; Gangaja, Binitha; Srikrishnarka, Pillalamarri; Unni, Gautam E.; Nair, A. Sreekumaran; Nair, Shantikumar V.; Santhanagopalan, Dhamodaran

    2017-03-01

    Energy storage technologies are sensitively dependent on electrode film quality, thickness and process scalability. In Li-ion batteries, using additive-free titania (TiO2) as electrodes, we sought to show the potential of spray pyrolysis-deposited nanoengineered films with thicknesses up to 135 μm exhibiting ultra-high areal capacities. Detailed electron microscopic characterization indicated that the achieved thick films are composed of highly crystalline anatase TiO2 particles with sizes on the order of 10-12 nm and porous as well. A 135 μm thick film yielded ultra-high areal and volumetric capacities of 3.7 mAh cm-2 and 274 mAh cm-3, respectively, at 1C rate. Also the present work recorded high Coulombic efficiency and good cycling stability. The best previously achieved capacities for additive-free TiO2 films have been less than 0.25 mAh cm-2 and With additives, best reported areal capacity in the literature has been 2.5 mAh cm-2 at 1C rate, but only with electrode thickness as high as 1400 μm. Formation of through-the-thickness percolation of Ti3+ conductive network upon lithiation contributed substantially for the superior performance. Spray pyrolysis deposition of nanoparticulate TiO2 electrodes have the potential to yield volumetric capacities an order of magnitude higher than the other processes previously reported without sacrificing performance and process scalability.

  8. Mechanical Properties of Laser Beam Welded Ultra-high Strength Chromium Steel with Martensitic Microstructure

    Science.gov (United States)

    Dahmen, Martin; Janzen, Vitalij; Lindner, Stefan; Wagener, Rainer

    A new class of steels is going to be introduced into sheet manufacturing. Stainless ferritic and martensitic steels open up opportunities for sheet metal fabrication including hot stamping. A strength of up to 2 GPa at a fracture strain of 15% can be attained. Welding of these materials became apparently a challenge. Energy-reduced welding methods with in-situ heat treatment are required in order to ensure the delicate and complex heat control. Laser beam welding is the joining technique of choice to supply minimum heat input to the fusion process and to apply an efficient heat control. For two application cases, production of tailored blanks in as-rolled condition and welding in assembly in hot stamped conditions, welding processes have been developed. The welding suitability is shown in metallurgical investigations of the welds. Crash tests based on the KSII concept as well as fatigue tests prove the applicability of the joining method. For the case of assembly also joining with deep drawing and manganese boron steel was taken into consideration. The strength of the joint is determined by the weaker partner but can benefit from its ductility.

  9. Social Cognition in Individuals at Ultra-High Risk for Psychosis: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    R J M van Donkersgoed

    Full Text Available Treatment in the ultra-high risk stage for a psychotic episode is critical to the course of symptoms. Markers for the development of psychosis have been studied, to optimize the detection of people at risk of psychosis. One possible marker for the transition to psychosis is social cognition. To estimate effect sizes for social cognition based on a quantitative integration of the published evidence, we conducted a meta-analysis of social cognitive performance in people at ultra high risk (UHR.A literature search (1970-July 2015 was performed in PubMed, PsychINFO, Medline, Embase, and ISI Web of Science, using the search terms 'social cognition', 'theory of mind', 'emotion recognition', 'attributional style', 'social knowledge', 'social perception', 'empathy', 'at risk mental state', 'clinical high risk', 'psychosis prodrome', and 'ultra high risk'. The pooled effect size (Cohen's D and the effect sizes for each domain of social cognition were calculated. A random effects model with 95% confidence intervals was used.Seventeen studies were included in the analysis. The overall significant effect was of medium magnitude (d = 0.52, 95% Cl = 0.38-0.65. No moderator effects were found for age, gender and sample size. Sub-analyses demonstrated that individuals in the UHR phase show significant moderate deficits in affect recognition and affect discrimination in faces as well as in voices and in verbal Theory of Mind (TOM. Due to an insufficient amount of studies, we did not calculate an effect size for attributional bias and social perception/ knowledge. A majority of studies did not find a correlation between social cognition deficits and transition to psychosis, which may suggest that social cognition in general is not a useful marker for the development of psychosis. However some studies suggest the possible predictive value of verbal TOM and the recognition of specific emotions in faces for the transition into psychosis. More research is needed on

  10. Analyses of acute kidney injury biomarkers by ultra-high performance liquid chromatography with mass spectrometry.

    Science.gov (United States)

    Al Za'abi, Mohammed; Ali, Badreldin H; ALOthman, Zeid A; Ali, Imran

    2016-01-01

    The newly developed acute kidney injury biomarkers are very important for the early and timely detection of kidney diseases. This review contains details of the analyses of several acute kidney injury biomarkers using ultra-high performance liquid chromatography-mass spectrometry in urine and plasma samples. In this review we attempt to discuss some aspects of the types of the biomarkers, patents, sample preparation, and the analyses. Besides, efforts were also made to discuss the possible uses of superficially porous (core-shell) columns in traditional and inexpensive high-performance liquid chromatography instruments. Additionally, the challenges and the future prospects are also highlighted. The present review will be useful for the academicians, scientists, and clinicians for the early detection of acute kidney injury biomarkers.

  11. Surface modification of ultra high molecular weight polyethylene fibers via the sequential photoinduced graft polymerization

    Science.gov (United States)

    Li, Zhi; Zhang, Wei; Wang, Xinwei; Mai, Yongyi; Zhang, Yumei

    2011-06-01

    In this study, a sequential photoinduced graft polymerization process was proposed to improve the poor interfacial bonding property of ultra high molecular weight polyethylene (UHMWPE) fibers. The polymerization was initiated by dormant semipinacol (SP) groups and carried out in a thin liquid layer. Methacrylic acid (MAA) and acryl amide (AM) were grafted stepwise onto the surface of UHMWPE fibers. Attenuated total reflectance infrared spectroscopy (ATR-IR) and thermo gravimetric analysis (TGA) confirmed the grafting. The analysis result of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) indicated the structure of grafted chains. Scanning electron microscopy (SEM) images and atomic force microscopy (AFM) images revealed the apparent morphology changing, and the grafted layers were observed. Interfacial shear stress (IFSS) test of the modified fibers showed an extensively improved interfacial bonding property. The active groups grafted onto the fibers would supply enough anchor points for the chemical bonding with various resins or further reactions.

  12. Controlled Rolling and Controlled Cooling Technology of Ultra-High Strength Steel with 700 Mpa Grade

    Institute of Scientific and Technical Information of China (English)

    QI Shi-ze; ZHANG Pi-jun; DU Lin-xiu; LIU Xiang-hua; WANG Guo-dong

    2004-01-01

    With Gleeble-1500 system, the influences of rolling temperature, finishing temperature and cooling rate on the mechanical properties of two ultra-high strength steels were analyzed. The microstructure of the hot rolled specimens was observed by optical microscope, TEM and SEM. The TRIP of HSLA steels was studied. The results show that the yield stress of 700 Mpa can be reached for two steels. The controlled rolling and controlled cooling technology has different effects on two steels, but it is rational to adopt finishing temperature 800 ℃ for both of them. The microstructure of the steels is mainly bainite, and the influence factors of mechanical properties are the size of bainite, and the size, distribution, composition and morphology of secondary phases. The deformation of high molybdenum steels at a high temperature with a high cooling rate would promote TRIP.

  13. Nonparametric Independence Screening in Sparse Ultra-High Dimensional Additive Models

    CERN Document Server

    Fan, Jianqing; Song, Rui

    2011-01-01

    A variable screening procedure via correlation learning was proposed Fan and Lv (2008) to reduce dimensionality in sparse ultra-high dimensional models. Even when the true model is linear, the marginal regression can be highly nonlinear. To address this issue, we further extend the correlation learning to marginal nonparametric learning. Our nonparametric independence screening is called NIS, a specific member of the sure independence screening. Several closely related variable screening procedures are proposed. Under the nonparametric additive models, it is shown that under some mild technical conditions, the proposed independence screening methods enjoy a sure screening property. The extent to which the dimensionality can be reduced by independence screening is also explicitly quantified. As a methodological extension, an iterative nonparametric independence screening (INIS) is also proposed to enhance the finite sample performance for fitting sparse additive models. The simulation results and a real data a...

  14. Investigation of Plasma Eects in Ultra High Molecular Weight Polyethylene (UHMWPE) Cords

    DEFF Research Database (Denmark)

    Teodoru, Steluta; Kusano, Yukihiro; Rozlosnik, Noemi

    modication for improved wetting and/or adhesion with other polymeric materials. Atmospheric pressure plasma treatment is promising for this purpose due to its environmental compatibility, high treatment eects without aecting the textural characteristics of the bulk material, its applicability to a variety......Ultra-high-molecular-weight polyethylene (UHMWPE) has been widely used because of its high chemical stabil- ity, high impact strength, exibility and low cost. Its eld of applications includes use in composites, packing for microelectronic components and biomaterials, usually requiring its surface...... of shapes, and easy up-scaling and construction of in-line production processes. An atmospheric pressure dielectric barrier discharge (DBD) plasma is used to study surface modication eect on UHMWPE cords, operated at a frequency of ca. 40 kHz in He, He/O2, O2 and N2 gases. The cords were continuously...

  15. (Ultra high pressure homogenization for continuous high pressure sterilization of pumpable foods - a review

    Directory of Open Access Journals (Sweden)

    Erika eGeorget

    2014-08-01

    Full Text Available Bacterial spores have a strong resistance to both chemical and physical hurdles and create a risk for food industry which has been tackled by applying high thermal intensity treatments to sterilize food. These strong thermal treatments lead to reduction of the organoleptic and nutritional properties of food and alternative are actively searched for. Innovative hurdles offer an alternative to inactivate bacterial spores. In particular, recent technological developments have enabled a new generation of high pressure homogenizer working at pressures up to 400 MPa and thus opening new opportunities for high pressure sterilization of foods. In this short review, we summarize the work conducted on (ultra-high pressure homogenization (UHPH to inactivate endospores in model and food systems. Specific attention is given to process parameters (pressure, inlet and valve temperatures. This review gathers the current state of the art and underlines the potential of UHPH sterilization of pumpable foods while highlighting the needs for future work.

  16. Demonstration of ultra-high-Q small mode volume toroid microcavities on a chip

    CERN Document Server

    Kippenberg, T J; Vahala, K J

    2004-01-01

    Optical microcavities confine light spatially and temporally and find application in a wide range of fundamental and applied studies. In many areas, the microcavity figure of merit is not only determined by photon lifetime (or the equivalent quality-factor, Q), but also by simultaneous achievement of small mode volume V . Here we demonstrate ultra-high Q-factor small mode volume toroid microcavities on-a-chip, which exhibit a Q/V factor of more than $10^{6}(\\lambda/n)^{-3}$. These values are the highest reported to date for any chip-based microcavity. A corresponding Purcell factor in excess of 200 000 and a cavity finesse of $2.8\\times10^{6}$ is achieved, demonstrating that toroid microcavities are promising candidates for studies of the Purcell effect, cavity QED or biochemical sensing

  17. Demonstration of ultra-high-Q small mode volume toroid microcavities on a chip

    Science.gov (United States)

    Kippenberg, T. J.; Spillane, S. M.; Vahala, K. J.

    2004-12-01

    Optical microcavities confine light spatially and temporally and find application in a wide range of fundamental and applied studies. In many areas, the microcavity figure of merit is not only determined by photon lifetime (or the equivalent quality-factor, Q), but also by simultaneous achievement of small mode volume (V). Here we demonstrate ultra-high Q-factor small mode volume toroid microcavities on-a-chip, which exhibit a Q/V factor of more than 106(λ/n)-3. These values are the highest reported to date for any chip-based microcavity. A corresponding Purcell factor in excess of 200 000 and a cavity finesse of >2.8×106 is achieved, demonstrating that toroid microcavities are promising candidates for studies of the Purcell effect, cavity QED or biochemical sensing.

  18. Influence of amorphous silica on the hydration in ultra-high performance concrete

    Energy Technology Data Exchange (ETDEWEB)

    Oertel, Tina, E-mail: tina.oertel@isc.fraunhofer.de [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Inorganic Chemistry I, Universität Bayreuth, Universitätsstr. 30, 95440 Bayreuth (Germany); Helbig, Uta, E-mail: uta.helbig@th-nuernberg.de [Crystallography and X-ray Methods, Technische Hochschule Nürnberg Georg Simon Ohm, Wassertorstraße 10, 90489 Nürnberg (Germany); Hutter, Frank [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Kletti, Holger [Building Materials, Bauhaus–Universität Weimar, Coudraystr. 11, 99423 Weimar (Germany); Sextl, Gerhard [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Chemical Technology of Advanced Materials, Julius Maximilian Universität, Röntgenring 11, 97070 Würzburg (Germany)

    2014-04-01

    Amorphous silica particles (silica) are used in ultra-high performance concretes to densify the microstructure and accelerate the clinker hydration. It is still unclear whether silica predominantly increases the surface for the nucleation of C–S–H phases or dissolves and reacts pozzolanically. Furthermore, varying types of silica may have different and time dependent effects on the clinker hydration. The effects of different silica types were compared in this study by calorimetric analysis, scanning and transmission electron microscopy, in situ X-ray diffraction and compressive strength measurements. The silica component was silica fume, pyrogenic silica or silica synthesized by a wet-chemical route (Stoeber particles). Water-to-cement ratios were 0.23. Differences are observed between the silica for short reaction times (up to 3 days). Results indicate that silica fume and pyrogenic silica accelerate alite hydration by increasing the surface for nucleation of C–S–H phases whereas Stoeber particles show no accelerating effect.

  19. Droplet-based microfluidics platform for ultra-high-throughput bioprospecting of cellulolytic microorganisms.

    Science.gov (United States)

    Najah, Majdi; Calbrix, Raphaël; Mahendra-Wijaya, I Putu; Beneyton, Thomas; Griffiths, Andrew D; Drevelle, Antoine

    2014-12-18

    Discovery of microorganisms producing enzymes that can efficiently hydrolyze cellulosic biomass is of great importance for biofuel production. To date, however, only a miniscule fraction of natural biodiversity has been tested because of the relatively low throughput of screening systems and their limitation to screening only culturable microorganisms. Here, we describe an ultra-high-throughput droplet-based microfluidic system that allowed the screening of over 100,000 cells in less than 20 min. Uncultured bacteria from a wheat stubble field were screened directly by compartmentalization of single bacteria in 20 pl droplets containing a fluorogenic cellobiohydrolase substrate. Sorting of droplets based on cellobiohydrolase activity resulted in a bacterial population with 17- and 7-fold higher cellobiohydrolase and endogluconase activity, respectively, and very different taxonomic diversity than when selected for growth on medium containing starch and carboxymethylcellulose as carbon source.

  20. Effect of ultra high pressure homogenization treatment on the bioactive compounds of soya milk.

    Science.gov (United States)

    Toro-Funes, N; Bosch-Fusté, J; Veciana-Nogués, M T; Vidal-Carou, M C

    2014-01-01

    Ultra high pressure homogenization (UHPH) is a useful novel technology to obtain safe and high-quality liquid foods. The effect of UHPH at 200 and 300 MPa in combination with different inlet temperatures (Tin) (55, 65 and 75 °C) on the bioactive compounds of soya milk was studied. Total phytosterols increased with the higher combination of pressure and temperature. The main phytosterol was β-sitosterol, followed by stigmasterol and campesterol. Total tocopherols in UHPH-treated soya milks decreased as the temperature and pressure increased. UHPH treatment also affected the different chemical forms of tocopherols. No biogenic amines were detected in any of the analyzed soya milks. Meanwhile, the polyamines SPD and SPM were found in all soya milks, being stable to the UHPH treatment. Total isoflavones increased with the higher combination of pressure and temperature. No differences in the isoflavone profile were found, with β-glucoside conjugates being the predominant form.