WorldWideScience

Sample records for attaining ultra-high energies

  1. Ultra High Energy Cosmic Rays and Neutrinos

    CERN Document Server

    Aloisio, Roberto

    2016-01-01

    We discuss the production of ultra high energy neutrinos coming from the propagation of ultra high energy cosmic rays and in the framework of top-down models for the production of these extremely energetic particles. We show the importance of the detection of ultra high energy neutrinos that can be a fundamental diagnostic tool to solve the discrepancy in the observed chemical composition of ultra high energy cosmic rays and, at the extreme energies, can unveil new physics in connection with the recent cosmological observations of the possible presence of tensor modes in the fluctuation pattern of the cosmic microwave background.

  2. Ultra high energy cosmic ray horizons

    International Nuclear Information System (INIS)

    We calculate the horizons of ultra high energy cosmic rays assuming different primary nuclei ranging from proton to iron at ultra high energies (6.1019 eV). We show that sources of ultra high energy protons and heavy nuclei can originate from distances up to ∼180 Mpc, while low and intermediate mass nuclei can only originate in the local universe (<50 Mpc).

  3. Ultra high energy cosmic ray horizons

    Energy Technology Data Exchange (ETDEWEB)

    Busca, N.G. [Laboratoire d' Astroparticules at Cosmologie, 10, rue Alice Domon et Lonie Duquet, 75205 Paris Cedex 13 (France)

    2009-05-15

    We calculate the horizons of ultra high energy cosmic rays assuming different primary nuclei ranging from proton to iron at ultra high energies (6.10{sup 19} eV). We show that sources of ultra high energy protons and heavy nuclei can originate from distances up to approx180 Mpc, while low and intermediate mass nuclei can only originate in the local universe (<50 Mpc).

  4. Expectations for ultra-high energy interactions

    International Nuclear Information System (INIS)

    Strong interactions at ultra-high energies are discussed with emphasis on the hadrons produced in high energy collisions. Evidence is considered that quantum chromodynamics might be the right theory, and also some estimates are given of quantum chromodynamics asymptotic-freedom phenomena, the work under discussion being very preliminary. 6 references

  5. Galactic Ultra-High-Energy Cosmic Rays

    OpenAIRE

    Olinto, A. V.; Epstein, R. I.; P. Blasi(INAF Arcetri)

    1999-01-01

    The absence of the expected GZK cutoff strongly challenges the notion that the highest-energy cosmic rays are of distant extragalactic origin. We discuss the possibility that these ultra-high-energy events originate in our Galaxy and propose that they may be due to iron nuclei accelerated from young, strongly magnetic neutron stars. Newly formed pulsars accelerate ions from their surface through relativistic MHD winds. We find that pulsars whose initial spin periods are shorter than $\\sim 4 (...

  6. 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.

  7. 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.

  8. Ultra-High Energy Cosmic Rays

    Science.gov (United States)

    Colon, Rafael Antonio; Moncada, Roberto; Guerra, Juan; Anchordoqui, Luis

    2016-01-01

    The search for the origin(s) of ultra-high energy (UHE) cosmic rays (CR) remains one of the cornerstones of high energy astrophysics. The previously proposed sources of acceleration for these UHECRs were gamma-ray bursts (GRB) and active galactic nuclei (AGN) due to their energetic activity and powerful jets. However, a problem arises between the acceleration method and the observed CR spectrum. The CRs from GRBs or AGN jets are assumed to undergo Fermi acceleration and a source injection spectrum proportional to E^-2 is expected. However, the most recent fits to the spectrum and nuclear composition suggest an injection spectrum proportional to E^-1. It is well known that such a hard spectrum is characteristic of unipolar induction of rotating compact objects. When this method is applied to the AGN cores, they prove to be much too luminous to accelerate CR nuclei without photodisintegrating, thus creating significant energy losses. Instead, here we re-examine the possibility of these particles being accelerated around the much less luminous quasar remnants, or dead quasars. We compare the interaction times of curvature radiation and photodisintegration, the two primary energy loss considerations with the acceleration time scale. We show that the energy losses at the source are not significant enough as to prevent these CRs from reaching the maximum observed energies. Using data from observatories in the northern and southern sky, the Telescope Array and the Pierre Auger Observatory respectively, two hotspots have been discerned which have some associated quasar remnants that help to motivate our study.

  9. Ultra High-Energy Cosmic Ray Observations

    CERN Document Server

    Kampert, Karl-Heinz

    2008-01-01

    The year 2007 has furnished us with outstanding results about the origin of the most energetic cosmic rays: a flux suppression as expected from the GZK-effect has been observed in the data of the HiRes and Auger experiments and correlations between the positions of nearby AGN and the arrival directions of trans-GZK events have been observed by the Pierre Auger Observatory. The latter finding marks the beginning of ultra high-energy cosmic ray astronomy and is considered a major breakthrough starting to shed first light onto the sources of the most extreme particles in nature. This report summarizes those observations and includes other major advances of the field, mostly presented at the 30th International Cosmic Ray Conference held in Merida, Mexico, in July 2007. With increasing statistics becoming available from current and even terminated experiments, systematic differences amongst different experiments and techniques can be studied in detail which is hoped to improve our understanding of experimental tec...

  10. Cosmogenic neutrinos and ultra-high energy cosmic ray models

    Science.gov (United States)

    Aloisio, R.; Boncioli, D.; di Matteo, A.; Grillo, A. F.; Petrera, S.; Salamida, F.

    2015-10-01

    We use an updated version of SimProp, a Monte Carlo simulation scheme for the propagation of ultra-high energy cosmic rays, to compute cosmogenic neutrino fluxes expected on Earth in various scenarios. These fluxes are compared with the newly detected IceCube events at PeV energies and with recent experimental limits at EeV energies of the Pierre Auger Observatory. This comparison allows us to draw some interesting conclusions about the source models for ultra-high energy cosmic rays. We will show how the available experimental observations are almost at the level of constraining such models, mainly in terms of the injected chemical composition and cosmological evolution of sources. The results presented here will also be important in the evaluation of the discovery capabilities of the future planned ultra-high energy cosmic ray and neutrino observatories.

  11. Cosmogenic neutrinos and ultra-high energy cosmic ray models

    CERN Document Server

    Aloisio, R; di Matteo, A; Grillo, A F; Petrera, S; Salamida, F

    2015-01-01

    We use an updated version of SimProp, a Monte Carlo simulation scheme for the propagation of ultra-high energy cosmic rays, to compute cosmogenic neutrino fluxes expected on Earth in various scenarios. These fluxes are compared with the newly detected IceCube events at PeV energies and with recent experimental limits at EeV energies of the Pierre Auger Observatory. This comparison allows us to draw some interesting conclusions about the source models for ultra-high energy cosmic rays. We will show how the available experimental observations are almost at the level of constraining such models, mainly in terms of the injected chemical composition and cosmological evolution of sources. The results presented here will also be important in the evaluation of the discovery capabilities of the future planned ultra-high energy cosmic ray and neutrino observatories.

  12. Ultra High Energy Particle Astronomy, Neutrino Masses and Tau Airshowers

    OpenAIRE

    Fargion, D.; Khlopov, M.; Konoplich, R.; Lucentini, P. G. De Sanctis; De Santis, M.; Mele, B

    2003-01-01

    Ultra High Energy (UHE) neutrino Astronomy and relic Neutrino masses may play a key role in solving the Ultra High Energy Cosmic Ray (UHECR) puzzle within the Z-Showering model. Tau air-shower originated by UHE neutrino in matter may probe and amplify this expected UHE neutrino Astronomy. The discover of upcoming and horizontal tau air-showers (UPTAUs, HORTAUs), born by UHE, nu_tau interacting inside mount chains or along Earth Crust crown masses at the Horizons edges, will greatly amplify th...

  13. Propagation of ultra high energy cosmic rays

    CERN Document Server

    Stanev, Todor

    2008-01-01

    We briefly describe the energy loss processes of ultrahigh energy protons, heavier nuclei and gamma rays in interactions with the universal photon fields of the Universe. We then discuss the modification of the accelerated cosmic ray energy spectrum in propagation by the energy loss processes and the charged cosmic ray scattering in the extragalactic magnetic fields. The energy lost by the ultrahigh energy cosmic rays goes into gamma rays and neutrinos that carry additional information about the sources of highest energy particles. The new experimental results of the HiRes and the Auger collaborations are discussed in view of the predictions from propagation calculations.

  14. 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...

  15. A decay of the ultra-high-energy neutrino $\

    CERN Document Server

    Kuznetsov, A V; Serghienko, A V

    2010-01-01

    The width of the neutrino decay into the electron and $W$ boson in a strong external magnetic field is obtained from the imaginary part of the neutrino self-energy. This result corrects the formulae existing in the literature. The mean free path of an ultra-high energy neutrino in a strong magnetic field is calculated. An energy cutoff for neutrinos propagating in a strong field is defined.

  16. Cosmic rays at ultra high energies (Neutrinos!)

    CERN Document Server

    Ahlers, M; Tu, H; Ahlers, Markus; Ringwald, Andreas; Tu, Huitzu

    2006-01-01

    Resonant photopion production with the cosmic microwave background predicts a suppression of extragalactic protons above the famous Greisen-Zatsepin-Kuzmin cutoff at about E_{GZK} ~ 5 x 10^10 GeV. Current cosmic ray data measured by the AGASA and HiRes Collaborations do not unambiguously confirm the GZK cutoff and leave a window for speculations about the origin and chemical composition of the highest energy cosmic rays. In this work we analyze the possibility of strongly interacting neutrino primaries and derive model-independent quantitative requirements on the neutrino-nucleon inelastic cross section for a viable explanation of the cosmic ray data. Search results on weakly interacting cosmic particles from the AGASA and RICE experiments are taken into account simultaneously. Using a flexible parameterization of the inelastic neutrino-nucleon cross section we find that a combined fit of the data does not favor the Standard Model neutrino-nucleon inelastic cross section, but requires, at 90 % confidence leve...

  17. Ultra High Energy Cosmic Rays: present status and future prospects

    OpenAIRE

    Watson, A.A.

    2001-01-01

    Reasons for the current interest in cosmic rays above 10^19 eV are described. The latest results on the energy spectrum, arrival direction distribution and mass composition of cosmic rays are reviewed, including data that were reported after the meeting in Blois in June 2001. The enigma set by the existence of ultra high-energy cosmic rays remains. Ideas proposed to explain it are discussed and progress with the construction of the Pierre Auger Observatory is outlined.

  18. Ultra High Energy Cosmic Rays Propagation and Spectrum

    OpenAIRE

    Aloisio, Roberto

    2011-01-01

    The status of the observations of Ultra High Energy Cosmic Rays will be reviewed, focusing on the the latest results of HiRes and Auger observatories. A comprehensive analytical computation scheme to compute the expected UHECR spectrum on earth will be presented, applying such scheme to interpret the experimental results. The phenomenological scenarios favored by HiRes and Auger in terms of chemical composition and spectrum will be also presented.

  19. Neutrino properties from ultra-high energy cosmic neutrinos

    CERN Document Server

    Huang, Yanqi

    2015-01-01

    Neutrino properties can be constrained by the detection of ultra-high energy cosmic neutrinos (UHECNs). By using the updated global fitting results of neutrino mixing parameters, we present predictions on the neutrino flavor ratios at the Earth from three possibly astrophysical sources. Comparing with the latest IceCube data, we find that the normal hierarchy (NH) and inverted hierarchy (IH) cases from the initial ratios $\\phi_{\

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

    OpenAIRE

    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,...

  1. Ultra-high energy physics and standard basic principles

    OpenAIRE

    Gonzalez-Mestres Luis

    2014-01-01

    It has not yet been elucidated whether the observed flux suppression for ultra-high energy cosmic rays (UHECR) at energies above ≃ 4 x 1019 eV is a signature of the Greisen-Zatsepin-Kuzmin (GZK) cutoff or a consequence of other phenomena. In both cases, violations of the standard fundamental principles of Physics can be present and play a significant role. They can in particular modify cosmic-ray interactions, propagation or acceleration at very high energy. Thus, in a long-term program, UHEC...

  2. Observing Ultra-High Energy Cosmic Rays with Smartphones

    CERN Document Server

    Whiteson, Daniel; Shimmin, Chase; Brodie, Kyle; Burns, Dustin

    2014-01-01

    We propose a novel approach for observing cosmic rays at ultra-high energy ($>10^{18}$~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.

  3. 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.

  4. Observing Ultra-High Energy Cosmic Rays with Smartphones

    OpenAIRE

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

    2014-01-01

    We propose a novel approach for observing cosmic rays at ultra-high energy ($>10^{18}$~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 si...

  5. Determining neutrino absorption spectra at Ultra-High Energies

    OpenAIRE

    Scholten, Olaf; Van Vliet, Arjen

    2008-01-01

    A very efficient method to measure 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 with modern radio telescopes. In this work we investigate the sensitivity of this detection method to structures in the UHE neutrino spectrum caused by their absorption on the low-energy relic anti-neutr...

  6. 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.

  7. Radio detection of ultra-high energy cosmic neutrinos

    International Nuclear Information System (INIS)

    Ultra-high energy (UHE) neutrino astronomy constitutes a new window of observation onto the UHE universe. The detection and characterization of astrophysical neutrinos at the highest energies (E> 1018 eV) would reveal the sources of high-energy cosmic rays, the highest energy particles ever seen, and would constrain the evolution of such sources over time. UHE neutrino astrophysics also allows us to probe weak interaction couplings at energies much greater than those available at particle colliders. One promising way of detecting the highest energy neutrinos is through the radio emission created when they interact in a large volume of dielectric, such as ice. Here I discuss current results and future efforts to instrument large volumes of detector material with radio antennas to detect, point back, and characterize the energy of UHE astrophysical neutrinos

  8. The toes of the ultra high energy cosmic ray spectrum

    OpenAIRE

    Harari, Diego; Mollerach, Silvia; Roulet, Esteban

    1999-01-01

    We study the effects of the galactic magnetic field on the ultra high energy cosmic ray propagation. We show that the deflections of the cosmic ray trajectories can have many important implications such as (de)magnification of the cosmic ray fluxes by lensing effects (which can modify the spectrum of individual sources), the formation of multiple images of a source or the existence of regions of the sky to which the Earth is almost blind. The appearance of image pairs is related to the existe...

  9. Interpretation of ultra-high energy multi-messenger data

    Directory of Open Access Journals (Sweden)

    Sigl Günter

    2013-06-01

    Full Text Available Charged ultra-high energy cosmic rays above ∼1017 eV are most likely accelerated in powerful astrophysical objects that have to meet a number of requirements to reach energies beyond the highest energies observed, a few 1020 eV, among them sufficient electromagnetic power and further constraints on geometry and magnetic fields to avoid excessive energy losses during acceleration. Since charged particles are deflected in cosmic magnetic fields and do not always point back to their sources, it is challenging to identify them and to reconstruct a detailed understanding of the acceleration mechanism. Neutral secondaries such as γ−rays and neutrinos that are produced by interactions of primary cosmic rays within the source and during propagation can provide important complementary information. We provide a brief overview over how multi-messenger data can be exploited to learn more about source and propagation physics.

  10. 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.

  11. 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...

  12. 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.

  13. Simulations of ultra-high-energy cosmic rays propagation

    International Nuclear Information System (INIS)

    We compare two techniques for simulation of the propagation of ultra-high-energy cosmic rays (UHECR) in intergalactic space: the Monte Carlo approach and a method based on solving transport equations in one dimension. For the former, we adopt the publicly available tool CRPropa and for the latter, we use the code TransportCR, which has been developed by the first author and used in a number of applications, and is made available online with publishing this paper. While the CRPropa code is more universal, the transport equation solver has the advantage of a roughly 100 times higher calculation speed. We conclude that the methods give practically identical results for proton or neutron primaries if some accuracy improvements are introduced to the CRPropa code

  14. 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...

  15. 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.

  16. Origin of very high and ultra high energy cosmic rays

    CERN Document Server

    Blasi, Pasquale

    2014-01-01

    While there is some level of consensus on a Galactic origin of cosmic rays up to the knee ($E_{k}\\sim 3\\times 10^{15}$ eV) and on an extragalactic origin of cosmic rays with energy above $\\sim 10^{19}$ eV, the debate on the genesis of cosmic rays in the intermediate energy region has received much less attention, mainly because of the ambiguity intrinsic in defining such a region. The energy range between $10^{17}$ eV and $\\sim 10^{19}$ eV is likely to be the place where the transition from Galactic to extragalactic cosmic rays takes place. Hence the origin of these particles, though being of the highest importance from the physics point of view, it is also one of the most difficult aspects to investigate. Here I will illustrate some ideas concerning the sites of acceleration of these particles and the questions that their investigation may help answer, including the origin of \\underline{ultra} high energy cosmic rays.

  17. The Future of Ultra High Energy Cosmic Rays

    International Nuclear Information System (INIS)

    Contrary to earlier expectations, several cosmic ray events with energies above 1020 eV have been reported by a number of ultra-high energy cosmic ray observatories. According to the AGASA experiment, the flux of such events is well above the predicted Greisen-Zatsepin-Kuzmin cutoff due to the pion production of extragalactic cosmic ray protons off the cosmic microwave background. In addition to the relatively high flux of events, the isotropic distribution of arrival directions and an indication of small scale clustering strongly challenge all models proposed to resolve this puzzle. We discuss how the GZK cutoff is modified by the local distribution of galaxies and how astrophysical proton sources with soft injection spectra are ruled out by AGASA data. Sources with hard injection spectrum are barely allowed by the observed spectrum. If the most recent claims by AGASA that the highest energy events are due to clustered nuclei are confirmed, the most plausible explanation are astrophysical sources with very hard spectra such as extragalactic unipolar inductors. In addition, extragalactic magnetic fields need to be well below the current nano-Gauss upper limits. Alternatively, if the primaries are not nuclei, the need for new physics explanations is paramount. We present an overview of the theoretical proposals along with their most general signatures to be tested by upcoming experiments

  18. Ultra high energy photons and neutrinos with JEM-EUSO

    Science.gov (United States)

    Adams, J. H.; Ahmad, S.; Albert, J.-N.; Allard, D.; Anchordoqui, L.; Andreev, V.; Anzalone, A.; Arai, Y.; Asano, K.; Ave Pernas, M.; Baragatti, P.; Barrillon, P.; Batsch, T.; Bayer, J.; Bechini, R.; Belenguer, T.; Bellotti, R.; Belov, K.; Berlind, A. A.; Bertaina, M.; Biermann, P. L.; Biktemerova, S.; Blaksley, C.; Blanc, N.; Błȩcki, J.; Blin-Bondil, S.; Blümer, J.; Bobik, P.; Bogomilov, M.; Bonamente, M.; Briggs, M. S.; Briz, S.; Bruno, A.; Cafagna, F.; Campana, D.; Capdevielle, J.-N.; Caruso, R.; Casolino, M.; Cassardo, C.; Castellinic, G.; Catalano, C.; Catalano, G.; Cellino, A.; Chikawa, M.; Christl, M. J.; Cline, D.; Connaughton, V.; Conti, L.; Cordero, G.; Crawford, H. J.; Cremonini, R.; Csorna, S.; Dagoret-Campagne, S.; de Castro, A. J.; De Donato, C.; de la Taille, C.; De Santis, C.; del Peral, L.; Dell'Oro, A.; De Simone, N.; Di Martino, M.; Distratis, G.; Dulucq, F.; Dupieux, M.; Ebersoldt, A.; Ebisuzaki, T.; Engel, R.; Falk, S.; Fang, K.; Fenu, F.; Fernández-Gómez, I.; Ferrarese, S.; Finco, D.; Flamini, M.; Fornaro, C.; Franceschi, A.; Fujimoto, J.; Fukushima, M.; Galeotti, P.; Garipov, G.; Geary, J.; Gelmini, G.; Giraudo, G.; Gonchar, M.; González Alvarado, C.; Gorodetzky, P.; Guarino, F.; Guzmán, A.; Hachisu, Y.; Harlov, B.; Haungs, A.; Hernández Carretero, J.; Higashide, K.; Ikeda, D.; Ikeda, H.; Inoue, N.; Inoue, S.; Insolia, A.; Isgrò, F.; Itow, Y.; Joven, E.; Judd, E. G.; Jung, A.; Kajino, F.; Kajino, T.; Kaneko, I.; Karadzhov, Y.; Karczmarczyk, J.; Karus, M.; Katahira, K.; Kawai, K.; Kawasaki, Y.; Keilhauer, B.; Khrenov, B. A.; Kim, J.-S.; Kim, S.-W.; Kim, S.-W.; Kleifges, M.; Klimov, P. A.; Kolev, D.; Kreykenbohm, I.; Kudela, K.; Kurihara, Y.; Kusenko, A.; Kuznetsov, E.; Lacombe, M.; Lachaud, C.; Lee, J.; Licandro, J.; Lim, H.; López, F.; Maccarone, M. C.; Mannheim, K.; Maravilla, D.; Marcelli, L.; Marini, A.; Martinez, O.; Masciantonio, G.; Mase, K.; Matev, R.; Medina-Tanco, G.; Mernik, T.; Miyamoto, H.; Miyazaki, Y.; Mizumoto, Y.; Modestino, G.; Monaco, A.; Monnier-Ragaigne, D.; Morales de los Ríos, J. A.; Moretto, C.; Morozenko, V. S.; Mot, B.; Murakami, T.; Murakami, M. Nagano; Nagata, M.; Nagataki, S.; Nakamura, T.; Napolitano, T.; Naumov, D.; Nava, R.; Neronov, A.; Nomoto, K.; Nonaka, T.; Ogawa, T.; Ogio, S.; Ohmori, H.; Olinto, A. V.; Orleański, P.; Osteria, G.; Panasyuk, M. I.; Parizot, E.; Park, I. H.; Park, H. W.; Pastircak, B.; Patzak, T.; Paul, T.; Pennypacker, C.; Perez Cano, S.; Peter, T.; Picozza, P.; Pierog, T.; Piotrowski, L. W.; Piraino, S.; Plebaniak, Z.; Pollini, A.; Prat, P.; Prévôt, G.; Prieto, H.; Putis, M.; Reardon, P.; Reyes, M.; Ricci, M.; Rodríguez, I.; Rodríguez Frías, M. D.; Ronga, F.; Roth, M.; Rothkaehl, H.; Roudil, G.; Rusinov, I.; Rybczyński, M.; Sabau, M. D.; Sáez-Cano, G.; Sagawa, H.; Saito, A.; Sakaki, N.; Sakata, M.; Salazar, H.; Sánchez, S.; Santangelo, A.; Santiago Crúz, L.; Sanz Palomino, M.; Saprykin, O.; Sarazin, F.; Sato, H.; Sato, M.; Schanz, T.; Schieler, H.; Scotti, V.; Segreto, A.; Selmane, S.; Semikoz, D.; Serra, M.; Sharakin, S.; Shibata, T.; Shimizu, H. M.; Shinozaki, K.; Shirahama, T.; Siemieniec-Oziȩbło, G.; Silva López, H. H.; Sledd, J.; Słomińska, K.; Sobey, A.; Sugiyama, T.; Supanitsky, D.; Suzuki, M.; Szabelska, B.; Szabelski, J.; Tajima, F.; Tajima, N.; Tajima, T.; Takahashi, Y.; Takami, H.; Takeda, M.; Takizawa, Y.; Tenzer, C.; Tibolla, O.; Tkachev, L.; Tokuno, H.; Tomida, T.; Tone, N.; Toscano, S.; Trillaud, F.; Tsenov, R.; Tsunesada, Y.; Tsuno, K.; Tymieniecka, T.; Uchihori, Y.; Unger, M.; Vaduvescu, O.; Valdés-Galicia, J. F.; Vallania, P.; Valore, L.; Vankova, G.; Vigorito, C.; Villaseñor, L.; von Ballmoos, P.; Wada, S.; Watanabe, J.; Watanabe, S.; Watts, J.; Weber, M.; Weiler, T. J.; Wibig, T.; Wiencke, L.; Wille, M.; Wilms, J.; Włodarczyk, Z.; Yamamoto, T.; Yamamoto, Y.; Yang, J.; Yano, H.; Yashin, I. V.; Yonetoku, D.; Yoshida, K.; Yoshida, S.; Young, R.; Zotov, M. Yu.; Zuccaro Marchi, A.

    2015-11-01

    Ultra high energy photons and neutrinos are carriers of very important astrophysical information. They may be produced at the sites of cosmic ray acceleration or during the propagation of the cosmic rays in the intergalactic medium. In contrast to charged cosmic rays, photon and neutrino arrival directions point to the production site because they are not deflected by the magnetic fields of the Galaxy or the intergalactic medium. In this work we study the characteristics of the longitudinal development of showers initiated by photons and neutrinos at the highest energies. These studies are relevant for development of techniques for neutrino and photon identification by the JEM-EUSO telescope. In particular, we study the possibility of observing the multi-peak structure of very deep horizontal neutrino showers with JEM-EUSO. We also discuss the possibility to determine the flavor content of the incident neutrino flux by taking advantage of the different characteristics of the longitudinal profiles generated by different type of neutrinos. This is of grate importance for the study of the fundamental properties of neutrinos at the highest energies. Regarding photons, we discuss the detectability of the cosmogenic component by JEM-EUSO and also estimate the expected upper limits on the photon fraction which can be obtained from the future JEM-EUSO data for the case in which there are no photons in the samples.

  19. Underwater acoustic detection of ultra high energy neutrinos in Antares

    International Nuclear Information System (INIS)

    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 (1020+ eV) and for a single detector we estimate the sensitivity limit of this acoustic method to be of the order of E2*φ 106 GeV cm-2 sr-1*s-1, for an astrophysical flux 0 falling as 1/E2. (author)

  20. Fossil AGN jets as ultra high energy particle accelerators

    CERN Document Server

    Benford, Gregory

    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 the large-scale RFP field. We show that this field decay induces large-scale electric fields which can accelerate cosmic rays with an E^{-2} power-law up to ultra-high energies with a cut-off depending on the fossil parameters. The cut-off is expected to be rigidity dependent, implying the observed composition would change from light to heavy close to the cut-off if one or two nearby AGN fossils dominate. Given that several percent of the universe's volume may house such slowly decaying structures, these fossils may even...

  1. 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...

  2. 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.

  3. 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.

  4. Ultra-high energy physics and standard basic principles

    Directory of Open Access Journals (Sweden)

    Gonzalez-Mestres Luis

    2014-04-01

    Full Text Available It has not yet been elucidated whether the observed flux suppression for ultra-high energy cosmic rays (UHECR at energies above ≃ 4 x 1019 eV is a signature of the Greisen-Zatsepin-Kuzmin (GZK cutoff or a consequence of other phenomena. In both cases, violations of the standard fundamental principles of Physics can be present and play a significant role. They can in particular modify cosmic-ray interactions, propagation or acceleration at very high energy. Thus, in a long-term program, UHECR data can hopefully be used to test relativity, quantum mechanics, energy and momentum conservation, vacuum properties... as well as the elementariness of standard particles. Data on cosmic rays at energies ≃ 1020 eV may also be sensitive to new physics generated well beyond Planck scale. A typical example is provided by the search for possible signatures of a Lorentz symmetry violation (LSV associated to a privileged local reference frame (the "vacuum rest frame", VRF. If a VRF exists, the internal structure of standard particles at ultra-high energy can undergo substantial modifications. Similarly, the conventional particle symmetries may cease to be valid at such energies instead of heading to a grand unification and the structure of vacuum may no longer be governed by standard quantum field theory. Then, the question whether the notion of Planck scale still makes sense clearly becomes relevant and the very grounds of Cosmology can undergo essential modifications. UHECR studies naturally interact with the interpretation of WMAP and Planck observations. Recent Planck data analyses tend to confirm the possible existence of a privileged space direction. If the observed phenomenon turns out to be a signature of the spinorial space-time (SST we suggested in 1996-97, then conventional Particle Physics may correspond to the local properties of standard matter at low enough energy and large enough distances. This would clearly strengthen the cosmological

  5. 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...

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

    Science.gov (United States)

    Neff, M.; Anton, G.; Enzenhöfer, A.; Graf, K.; Hößl, J.; Katz, U.; Lahmann, R.

    2013-10-01

    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.

  7. 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 ...

  8. 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

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

    International Nuclear Information System (INIS)

    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 km3 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 km3 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 transmitters was

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

    OpenAIRE

    Liu, Ruo-Yu; Wang, Xiang-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...

  11. SimProp: a simulation code for ultra high energy cosmic ray propagation

    International Nuclear Information System (INIS)

    A new Monte Carlo simulation code for the propagation of Ultra High Energy Cosmic Rays is presented. The results of this simulation scheme are tested by comparison with results of another Monte Carlo computation as well as with the results obtained by directly solving the kinetic equation for the propagation of Ultra High Energy Cosmic Rays. A short comparison with the latest flux published by the Pierre Auger collaboration is also presented

  12. SimProp: a simulation code for ultra high energy cosmic ray propagation

    Energy Technology Data Exchange (ETDEWEB)

    Aloisio, R.; Grillo, A.F. [INAF Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze (Italy); Boncioli, D. [INFN and Physics Department, University of Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Petrera, S.; Salamida, F., E-mail: aloisio@arcetri.astro.it, E-mail: denise.boncioli@roma2.infn.it, E-mail: grillo@lngs.infn.it, E-mail: petrera@aquila.infn.it, E-mail: salamida@ipno.in2p3.fr [INFN and Physics Department, University of L' Aquila, L' Aquila (Italy)

    2012-10-01

    A new Monte Carlo simulation code for the propagation of Ultra High Energy Cosmic Rays is presented. The results of this simulation scheme are tested by comparison with results of another Monte Carlo computation as well as with the results obtained by directly solving the kinetic equation for the propagation of Ultra High Energy Cosmic Rays. A short comparison with the latest flux published by the Pierre Auger collaboration is also presented.

  13. COMPUTATIONAL SCHEMES FOR THE PROPAGATION OF ULTRA HIGH ENERGY COSMIC RAYS

    Directory of Open Access Journals (Sweden)

    Roberto Aloisio

    2013-12-01

    Full Text Available We discuss the problem of ultra high energy particles propagation in astrophysical backgrounds. We present two different computational schemes based on 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, which give quite reliable results, enable the computation of fluxes keeping track of the different primary and secondary components, providing a fast and useful workbench for studying Ultra High Energy Cosmic Rays.

  14. High energy gamma ray counterparts of astrophysical sources of ultra-high energy cosmic rays

    OpenAIRE

    C. Ferrigno(ISDC); P. Blasi(INAF Arcetri); De Marco, D.

    2004-01-01

    If ultra-high energy cosmic rays (UHECRs) are accelerated at astrophysical point sources, the identification of such sources can be achieved if there is some kind of radiation at observable wavelengths that may be associated with the acceleration and/or propagation processes. No radiation of this type has so far been detected or at least no such connection has been claimed. The process of photopion production during the propagation of UHECRs from the sources to the Earth results in the genera...

  15. Ultra High Energy Neutrinos from Gamma-Ray Burst Afterglows Using the Swift-UVOT Data

    CERN Document Server

    Nir, Guy; Landsman, Hagar; Behar, Ehud

    2015-01-01

    We consider a sample of 107 Gamma Ray Bursts (GRBs) for which early UV emission was measured by Swift, and extrapolate the photon intensity to lower energies. Protons accelerated in the GRB jet may interact with such photons to produce charged pions and subsequently ultra high energy neutrinos $\\varepsilon_\

  16. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    Czech Academy of Sciences Publication Activity Database

    Alvarez-Muñiz, J.; Soares, E.A.; Berlin, A.; Bogdan, M.; Boháčová, Martina; Bonifazi, C.; Carvalho, W.R.; de Mello Neto, J.R.T.; San Luis, P.F.; Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.; Ramos de Castro, A.; Reyes, L.C.; Richardson, M.; Rouille D’Orfeuil, B.; Santos, E.M.; Wayne, S.; Williams, C.; Zas, E.; Zhou, J.

    2013-01-01

    Roč. 719, Aug (2013), s. 70-80. ISSN 0168-9002 Institutional support: RVO:68378271 Keywords : ultra high energy cosmic rays * radio-detection * microwave * GHz Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.316, year: 2013

  17. Ultra-High-Energy Cosmic Ray Acceleration by Magnetic Reconnection in Newborn Pulsars

    CERN Document Server

    De Gouveia dal Pino, E M

    2000-01-01

    We here investigate the possibility that the ultra-high energy cosmic ray(UHECR) events observed above the GZK limit are mostly protons accelerated ineconnection sites just above the magnetosphere of newborn millisecond pulsarswhich are originated by accretion induced collapse (AIC).

  18. Ultra-high energy neutrino interactions and compositeness

    International Nuclear Information System (INIS)

    This paper reviews the arguments leading to the suggestion that muon-rich extensive air showers (EAS) and underground muon bursts associated with point sources in the sky may be caused by neutrinos rather than photons. If quarks and leptons possess a substructure with a characteristic energy scale Λ, neutrinos are capable of interacting with cross sections much larger than predicted by the standard model, once the CMS energy exceeds Λ. The authors give estimates of the energy and angular distributions of hard anomalous neutrino interactions. Experiments are suggested in order to distinguish between photon and neutrino primaries

  19. Ultra high temperature latent heat energy storage and thermophotovoltaic energy conversion

    OpenAIRE

    Datas Medina, Alejandro; Ramos Cabal, Alba; Martí Vega, Antonio; Cañizo Nadal, Carlos del; Luque López, Antonio

    2016-01-01

    A conceptual energy storage system design that utilizes ultra high temperature phase change materials is presented. In this system, the energy is stored in the form of latent heat and converted to electricity upon demand by TPV (thermophotovoltaic) cells. Silicon is considered in this study as PCM (phase change material) due to its extremely high latent heat (1800 J/g or 500 Wh/kg), melting point (1410 C), thermal conductivity (~25 W/mK), low cost (less than $2/kg or $4/kWh) and a...

  20. Space Time Fluctuations and Ultra High Energy Cosmic Ray Interactions

    OpenAIRE

    R. AloisioINFN/LNGS; P. Blasi(INAF Arcetri); A. Galante(Univ. L'Aquila); P. L. Ghia(CNR and INFN Torino); Grillo, A. F.

    2002-01-01

    The intimate geometry of space-time is expected to suffer stochastic fluctuations as a result of quantum gravitational effects. These fluctuations may induce observable consequences on the propagation of high energy particles over large distances, so that the strength and the characteristics of these fluctuations may be constrained, mainly in the range of energies of interest for cosmic ray physics. While invoked as a possible explanation for the detection of the puzzling co...

  1. A new physical phenomenon in ultra-high energy collisions

    Directory of Open Access Journals (Sweden)

    Allen Jeffrey D.

    2013-06-01

    Full Text Available We show that combining the published Pierre Auger Observatory measurements of the longitudinal and lateral properties of UHE atmospheric showers, points to an unforeseen change in the nature of particle interactions at ultrahigh energy. A “toy model” of UHE proton-air interactions is presented which provides the first fully consistent description of air shower observations. It demonstrates that the observed energy dependence of the depth-of-shower-maximum distribution may not indicate a transition to a heavier composition, as commonly assumed. While fundamentally phenomenological, the model is based on considerations of how the normal vacuum of QCD might be vaporized and chiral symmetry restored by the extreme energy densities produced in UHE collisions. Whatever its origin, understanding this unexpected phenomenon opens exciting directions in particle physics and may impact Early Universe cosmology.

  2. Ultra High Energy Cosmic Rays: origin and propagation

    CERN Document Server

    Stanev, Todor

    2007-01-01

    We discuss the basic difficulties in understanding the origin of the highest energy particles in the Universe - the ultrahigh energy cosmic rays (UHECR). It is difficult to imagine the sources they are accelerated in. Because of the strong attenuation of UHECR on their propagation from the sources to us these sources should be at cosmologically short distance from us but are currently not identified. We also give information of the most recent experimental results including the ones reported at this conference and compare them to models of the UHECR origin.

  3. 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...

  4. 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.

  5. Advanced intermediate temperature sodium–nickel chloride batteries with ultra-high energy density

    OpenAIRE

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Y.; Meinhardt, Kerry D.; Chang, Hee Jung; Canfield, Nathan L.; Vincent L. Sprenkle

    2016-01-01

    Sodium-metal halide batteries have been considered as one of the more attractive technologies for stationary electrical energy storage, however, they are not used for broader applications despite their relatively well-known redox system. One of the roadblocks hindering market penetration is the high-operating temperature. Here we demonstrate that planar sodium–nickel chloride batteries can be operated at an intermediate temperature of 190 °C with ultra-high energy density. A specific energy d...

  6. Testing for uniformity of ultra-high energy cosmic ray arrival directions

    Science.gov (United States)

    Ivanov, A. A.

    2016-04-01

    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 (RA) using two methods appropriate for the energy ranges below and above 1018 eV. No statistically significant deviation from uniformity is found in the arrival directions of cosmic rays (CRs) detected within the observation period 1974-2000.

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

    OpenAIRE

    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 peri...

  8. New physics with ultra-high-energy neutrinos

    International Nuclear Information System (INIS)

    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

  9. On astrophysical solution to ultra high energy cosmic rays

    OpenAIRE

    Berezinsky, V.; Gazizov, A. Z.; Grigorieva, S. I.

    2002-01-01

    We argue that an astrophysical solution to UHECR problem is viable. The pectral features of extragalactic protons interacting with CMB are calculated in model-independent way. Using the power-law generation spectrum $\\propto E^{-\\gamma_g}$ as the only assumption, we analyze four features of the proton spectrum: the GZK cutoff, dip, bump and the second dip. We found the dip, induced by electron-positron production on CMB, as the most robust feature, existing in energy range $1\\times 10^{18} - ...

  10. Cosmic gamma radiation of ultra high energy of primordial origin

    International Nuclear Information System (INIS)

    The quantum mechanical effects near a collapsing black hole as shown by Stephen W.Hawking in 1974 to produce streaming particles through tunneling effect was explored in the context of cosmic gamma ray production. In this thesis, we show the possible production of gamma rays of high energies (ν approx 1041 Hz) in the initial stages of the formation of the Universe by the explosion of primordial mini black holes. These mini black hole explosions happening at 10-43 s to 10-37 s after the start perhaps may account for the existing universal cosmic background radiation of 2.70K. (Author)

  11. Towards autonomous radio detection of ultra high energy cosmic rays

    International Nuclear Information System (INIS)

    The radio-detection of extensive air showers, investigated for the first time in the 1960's, obtained promising results but plagued by the technical limitations. At that time, H.R. Allan summed up the state of the art in an extensive review article whose conclusions and predictions are still used today. Set up in 2001 at the Nancay Observatory, the CODALEMA experiment was built first as a demonstrator and successfully showed the feasibility of the radio-detection of extensive air showers. Radically modified in 2005, it allowed to obtain a clear energy correlation, and put in evidence an unambiguous signature of the geomagnetic origin of the electric field emission process associated to the air shower. The switch towards large areas is the next step of the technique's development. Therefore, the autonomy of the detectors becomes essential. After test prototypes installed in 2006 at the Pierre Auger Observatory, a generation of new autonomous detectors was developed. Their first results will be presented. This work is also dedicated to the issues related to the radio-detection technique: the antenna response, the sensitivity, the surrounding effects, the monitoring of a big array. The determination of the shower characteristics independently of other detectors such as the lateral distribution, the energy correlation and the frequency spectrum of the radio transient will be discussed. (author)

  12. 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.

  13. 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.

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

    CERN Document Server

    Healy, M D

    2007-01-01

    Data taken at the Pierre Auger Observatory are used to search for air showers initiated by ultra-high energy (UHE) photons. Results of searches are reported from hybrid observations where events are measured with both fluorescence and array detectors. Additionally, a more stringent test of the photon fluxes predicted with energies above 10^19 eV is made using a larger data set measured using only the surface detectors of the observatory.

  15. Detectability of Space-Time Fluctuations in Ultra High Energy Cosmic Ray Experiments

    OpenAIRE

    R. AloisioINFN/LNGS; P. BlasiINAF Arcetri; A. GalanteUniv. L'Aquila; P. L. GhiaCNR and INFN Torino; A. F. GrilloINFN LNGS

    2002-01-01

    It is generally expected that quantum gravity affects the structure of space-time by introducing stochastic fluctuations in the geometry, and, ultimately, in the measurements of four-distances and four-momenta.These fluctuations may induce observable consequences on the propagation of ultra high energy particles, mainly in the range of energies of interest for cosmic ray physics, over large distances, leading to their detection or constraining the underlying quantum gravitat...

  16. Absolute energy calibration of ultra-high energy cosmic telescope with a portable electron linear accelerator

    International Nuclear Information System (INIS)

    Telescope Array experiment (TA) which observes the ultra-high energy cosmic rays (UHECRs) was started from 2008 at Utah State in U.S. We will calibrate the absolute energy scale of fluorescence detector (FD) with a portable electron linear accelerator (ELS) of which typical beam intensity is 40 MeV x 109 e- per pulse. The ELS is installed at 100 m from the FD. We operated the ELS every about four months, and took data for energy calibration. The most important beam study is measurement of beam charge of each pulse. In this article, we will report about the beam charge measurement study and first results of FD absolute energy calibration with the ELS. (author)

  17. Ultra-high energy cosmic rays and the extragalactic gamma ray flux

    CERN Document Server

    Erlykin, A D

    2014-01-01

    Ultra-high energy cosmic rays interacting with the radiation fields in the universe cause electromagnetic cascades resulting in a flux of extragalactic gamma rays, detectable to some 100 GeV. Recent precise measurements of the extragalactic gamma ray flux by Fermi-LAT, coupled with estimates of the background from active galactic nuclei of various types, allows limits to be set on the cascade component. By comparison with prediction and, making various assumptions, ie taking a particular model, limits can be set on the maximum energy to which ultra-high energy particle can be accelerated. If our model is correct, it is unlikely that the maximum energy is above 100 EeV, in turn, the apparent 'GZK' cut-off in the measured ultra-high energy spectrum could instead be due to a fall-off in the intrinsic emergent particle spectrum. However, it is not plausible to be dogmatic at the present time because of uncertainty in many of the parameters involved. We have used recent estimates of the range of parameters and hav...

  18. Experimental Limit on the Cosmic Diffuse Ultra-high Energy Neutrino Flux

    CERN Document Server

    Gorham, P W; Liewer, K M; Naudet, C J; Saltzberg, D; Williams, D

    2003-01-01

    We report results from 120 hours of livetime with the Goldstone Lunar Ultra-high energy neutrino Experiment (GLUE). The experiment searches for 100 EeV neutrinos in the lunar regolith. Triggering on a timing coincidence between the two telescopes significantly reduces the terrestrial interference background, allowing operation at the thermal noise level. No candidates are yet seen. We report on limits implied by this non-detection, based on Monte Carlo estimates of the efficiency.

  19. Ultra-High Energy Cosmic Ray Probes of Large Scale Structure and Magnetic Fields

    OpenAIRE

    Sigl, Guenter; Miniati, Francesco; Ensslin, Torsten

    2004-01-01

    We study signatures of a structured universe in the multi-pole moments, auto-correlation function, and cluster statistics of ultra-high energy cosmic rays above 10^19 eV. We compare scenarios where the sources are distributed homogeneously or according to the baryon density distribution obtained from a cosmological large scale structure simulation. The influence of extragalactic magnetic fields is studied by comparing the case of negligible fields with fields expected to be produced along lar...

  20. Composition studies of Ultra High Energy Cosmic Rays using Data of the Pierre Auger Observatory

    OpenAIRE

    Caballero Mora, Karen Salomé

    2010-01-01

    The subject of this work is the estimation of the mass composition of Ultra High Energy Cosmic Rays recorded by the surface detector of the Pierre Auger Observatory. The time traces of the surface detector stations are explored to obtain a new observable sensitive to the mass composition. The new observable is calibrated with the most mass-sensitive observable of the Observatory, the depth of the shower maximum to obtain a new estimation. Results on mass composition, from this, are reported.

  1. Inverse problem for transport equation of ultra-high energy cosmic rays

    International Nuclear Information System (INIS)

    Propagation of ultra-high energy nuclei in expending universe filled with background radiation is considered. We developed numerical code for solution of inverse problem for cosmic-ray transport equation that allows determination of source spectrum from the spectrum observed at the Earth. The injection spectra of protons and iron nuclei in extragalactic sources are found assuming that these species dominate in the source composition. Data from the Auger and Telescope Array experiments are used to illustrate the method.

  2. Ultra high energy cosmic rays: implications of Auger data for source spectra and chemical composition

    OpenAIRE

    Aloisio, R.; Berezinsky, V.; P. Blasi(INAF Arcetri)

    2013-01-01

    We use a kinetic-equation approach to describe the propagation of ultra high energy cosmic ray protons and nuclei and calculate the expected spectra and mass composition at the Earth for different assumptions on the source injection spectra and chemical abundances. When compared with the spectrum, the elongation rate $X_{max}(E)$ and dispersion $\\sigma(X_{max})$ as observed with the Pierre Auger Observatory, several important consequences can be drawn: a) the injection spectra of nuclei must ...

  3. 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.

  4. Ultra-high energy neutrino dispersion in plasma and radiative transition $\

    CERN Document Server

    Kuznetsov, A V; Shitova, A M

    2011-01-01

    Qualitative analysis of additional energy of neutrino and antineutrino in plasma is performed. A general expression for the neutrino self-energy operator is obtained in the case of ultra-high energies when the local limit of the weak interaction is not valid. The neutrino and antineutrino additional energy in plasma is calculated using the dependence of the $W$ and $Z$--boson propagators on the momentum transferred. The kinematical region for the neutrino radiative transition (the so-called "neutrino spin light") is established for some important astrophysical cases. For high energy neutrino and antineutrino, dominating transition channels in plasma, $\

  5. Ultra High Energy Cosmic Ray and UHE Neutrino-Z Showering in Dark Halos

    OpenAIRE

    Fargion, Daniele; Lucentini, P. G. De Sanctis; Grossi, M; De Santis, M; Mele, Barbara

    2001-01-01

    The Ultra High Energy Cosmic Ray (UHECR), by UHE neutrino-relic neutrino--Z showering in Hot Dark Halos (HDM), shows an energy spectra, an anisotropy following the relic neutrino masses and clustering in dark halo. The lighter are the relic neutrinos masses, the higher their corresponding Z resonance energy peaks. A twin light neutrino mass splitting may reflect into a twin Z resonance and a complex UHECR spectra modulation as a twin bump at at highest GZK energy cut-off. Each possible neutri...

  6. EFFECTIVE FRACTURE ENERGY OF ULTRA-HIGH-PERFORMANCE FIBRE-REINFORCED CONCRETE UNDER INCREASED STRAIN RATES

    Directory of Open Access Journals (Sweden)

    Radoslav Sovják

    2014-10-01

    Full Text Available The main objective of this paper is to contribute to the development of ultra-high performance fibre reinforced concrete (UHPFRC with respect to its effective fracture energy. Effective fracture energy was investigated in this paper considering different fibre volume fractions and different strain rates. It was concluded that the effective fracture energy is dependent on the strain rate. In addition, it was found that higher fibre volume fractions tend to decrease the sensitivity of the UHPFRC to increased strain rates.

  7. Ultra-High Energy Cosmic Rays from Young Neutron Star Winds

    OpenAIRE

    P. Blasi(INAF Arcetri); Epstein, R. I.; Olinto, A. V.

    1999-01-01

    The long-held notion that the highest-energy cosmic rays are of distant extragalactic origin is challenged by observations that events above $\\sim 10^{20}$ eV do not exhibit the expected high-energy cutoff from photopion production off the cosmic microwave background. We suggest that these unexpected ultra-high-energy events are due to iron nuclei accelerated from young strongly magnetized neutron stars through relativistic MHD winds. We find that neutron stars whose initial spin periods are ...

  8. 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 ...

  9. Ultra-high energy cosmic rays: a probe into new physics

    International Nuclear Information System (INIS)

    The most energetic particles ever detected exceed 1020 eV in energy. Their existence represents at the same time a great challenge for particle physics and astrophysics, and a great promise of providing us for a probe of the validity of the laws of Nature in extreme conditions. We review here the most recent data and the future perspectives for detection of cosmic rays at ultra-high energies, and discuss possible ways of using these data to test the possibility that new Physics and/or new Astrophysics may be awaiting around the corner

  10. Ultra-high energy cosmic rays a probe into New Physics

    CERN Document Server

    Blasi, P

    2002-01-01

    The most energetic particles ever detected exceed $10^{20}$ eV in energy. Their existence represents at the same time a great challenge for particle physics and astrophysics, and a great promise of providing us for a probe of the validity of the laws of Nature in extreme conditions. We review here the most recent data and the future perspectives for detection of cosmic rays at ultra-high energies, and discuss possible ways of using these data to test the possibility that new Physics and/or new Astrophsyics may be awaiting around the corner.

  11. Ultra-high Energy Cosmic Rays: a probe into New Physics

    OpenAIRE

    Blasi, Pasquale

    2002-01-01

    The most energetic particles ever detected exceed $10^{20}$ eV in energy. Their existence represents at the same time a great challenge for particle physics and astrophysics, and a great promise of providing us for a probe of the validity of the laws of Nature in extreme conditions. We review here the most recent data and the future perspectives for detection of cosmic rays at ultra-high energies, and discuss possible ways of using these data to test the possibility that new Physics and/or ne...

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

    OpenAIRE

    De Domenico, Manlio; Lyberis, Haris; 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 e...

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

    OpenAIRE

    Settimo, Mariangela; De Domenico, Manlio

    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 inter...

  14. The First Limits on the Ultra-high Energy Neutrino Fluence from Gamma-ray Bursts

    OpenAIRE

    Vieregg, A. G.; Palladino, K.; Allison, P.; Baughman, B. M.; Beatty, J. J.; Belov, K.; Besson, D. Z.; Bevan, S; Binns, W. R.; Chen, C.; Chen, P; Clem, J. M.; Connolly, A.; Detrixhe, M.; De Marco, D.

    2011-01-01

    We set the first limits on the ultra-high energy (UHE) neutrino fluence at energies greater than 10^9 GeV from gamma-ray bursts (GRBs) based on data from the second flight of the ANtarctic Impulsive Transient Antenna (ANITA). During the 31 day flight of ANITA-II, 26 GRBs were recorded by Swift or Fermi. Of these, we analyzed the 12 GRBs which occurred during quiet periods when the payload was away from anthropogenic activity. In a blind analysis, we observe 0 events on a total background of 0...

  15. Search for ultra-high energy photons and neutrinos using Telescope Array surface detector

    Directory of Open Access Journals (Sweden)

    Troitsky S.V.

    2013-06-01

    Full Text Available We search for ultra-high energy photons by analyzing geometrical properties of shower fronts of events registered by the Telescope Array surface detector. By making use of an event-by-event statistical method, we derive upper limits on the absolute flux of primary photons with energies above 1019eV, 1019.5eV and above 1020eV based on the three years data from Telescope Array surface detector (May 2008 – May 2011. We report the results of down-going neutrino search based on the analysis of very inclined events.

  16. On ultra-high energy cosmic ray acceleration at the termination shock of young pulsar winds

    CERN Document Server

    Lemoine, Martin; Pétri, Jérôme

    2014-01-01

    We examine the possibility that pulsars born with $\\sim\\,$millisecond periods can accelerate ions to ultra-high energies at the termination shock of the pulsar wind. Assuming that such pulsars inject ions into the wind, and that the wind luminosity is substantially converted into particle random kinetic energy through dissipation/acceleration processes around the termination shock, we find that the confinement energy can be as large as $4\\times10^{20}\\,$eV for protons, for a fiducial rotation period $P=1\\,$msec and a pulsar magnetic field $B_{\\star}=10^{13}\\,$G, implying a fiducial wind luminosity $L_{\\rm p}\\,\\sim\\,10^{45}\\,$erg/s and a spin-down time $t_{\\rm sd}\\,\\sim 3\\times 10^7\\,$s; the maximum energy associated to photopion interactions (for protons) is even larger, for the same fiducial parameters. Therefore, such sources could indeed populate the ultra-high energy cosmic ray range with nuclei. We derive an associated neutrino flux produced by interactions in the source region. Our maximum flux lies sli...

  17. 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.

  18. Status of Goldstone Lunar Ultra-High Energy Neutrino Experiment (GLUE)

    Science.gov (United States)

    Gorham, Peter W.; Liewer, Kurt M.; Milincic, Radovan; Naudet, Charles J.; Saltzberg, David; Williams, Dawn

    2003-02-01

    We report on results from 80 hours of livetime with the Goldstone Lunar Ultra-high energy neutrino Experiment (GLUE). The experiment searches for microwave pulses (width optical fiber. Such pulses would arise from subsurface electromagnetic cascades induced by interactions of up-coming ~ 100 EeV neutrinos in the lunar regolith. Triggering on a timing coincidence between the two telescopes significantly reduces the terrestrial interference background, allowing operation at the thermal noise level. No unambiguous candidates are yet seen. We report on limits implied by this non-detection, based on new Monte Carlo estimates of the efficiency.

  19. Search for emission of ultra high energy radiation from active galactic nuclei

    International Nuclear Information System (INIS)

    A search for emission of ultra-high energy gamma radiation from 13 active galactic nuclei that were detected by EGRET, using the CYGNUS extensive air-shower array, is described. The data set has been searched for continuous emission, emission on the time scale of one week, and for on the time scale of out day. No evidence for emission from any of the AGN on any of the time scales examined was found. The 90% C.L. upper limit to the continuous flux from Mrk 421 above 50 TeV is 7.5 x 10-14 cm-2s-1

  20. Simulation of Ultra-High Energy Photon Propagation in the Geomagnetic Field

    OpenAIRE

    Homola, P.; Gora, D.; Heck, D.; Klages, H.; Pekala, J.; Risse, M.; Wilczynska, B.; Wilczynski, H.

    2003-01-01

    The identification of primary photons or specifying stringent limits on the photon flux is of major importance for understanding the origin of ultra-high energy (UHE) cosmic rays. We present a new Monte Carlo program allowing detailed studies of conversion and cascading of UHE photons in the geomagnetic field. The program named PRESHOWER can be used both as an independent tool or together with a shower simulation code. With the stand-alone version of the code it is possible to investigate var...

  1. Search for emission of ultra high energy radiation from active galactic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    A search for emission of ultra-high energy gamma radiation from 13 active galactic nuclei that were detected by EGRET, using the CYGNUS extensive air-shower array, is described. The data set has been searched for continuous emission, emission on the time scale of one week, and for on the time scale of out day. No evidence for emission from any of the AGN on any of the time scales examined was found. The 90% C.L. upper limit to the continuous flux from Mrk 421 above 50 TeV is 7.5 [times] 10[sup [minus]14] cm[sup [minus]2]s[sup [minus]1].

  2. Search for emission of ultra high energy radiation from active galactic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    The CYGNUS Collaboration

    1993-05-01

    A search for emission of ultra-high energy gamma radiation from 13 active galactic nuclei that were detected by EGRET, using the CYGNUS extensive air-shower array, is described. The data set has been searched for continuous emission, emission on the time scale of one week, and for on the time scale of out day. No evidence for emission from any of the AGN on any of the time scales examined was found. The 90% C.L. upper limit to the continuous flux from Mrk 421 above 50 TeV is 7.5 {times} 10{sup {minus}14} cm{sup {minus}2}s{sup {minus}1}.

  3. Thermal effects on the absorption of ultra-high energy neutrinos by the cosmic neutrino background

    International Nuclear Information System (INIS)

    We use the formalism of finite-temperature field theory to study the interactions of ultra-high energy (UHE) cosmic neutrinos with the background of relic neutrinos and to derive general expressions for the UHE neutrino transmission probability. This approach allows us to take into account the thermal effects introduced by the momentum distribution of the relic neutrinos. We compare our results with the approximate expressions existing in the literature and discuss the influence of thermal effects on the absorption dips in the context of favoured neutrino mass schemes, as well as in the case of clustered relic neutrinos

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

    OpenAIRE

    Fujii, T.; Malacari, M.; 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.

    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 Telescopes (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 t...

  5. Investigation of the Galactic Magnetic Field with Ultra-High Energy Cosmic Rays

    CERN Document Server

    Erdmann, Martin; Urban, Martin

    2015-01-01

    We present a method to correct for deflections of ultra-high energy cosmic rays in the galactic magnetic field. We perform these corrections by simulating the expected arrival directions of protons using a parameterization of the field derived from Faraday rotation and synchrotron emission measurements. To evaluate the method we introduce a simulated astrophysical scenario and two observables designed for testing cosmic ray deflections. We show that protons can be identified by taking advantage of the galactic magnetic field pattern. Consequently, cosmic ray deflection in the galactic field can be verified experimentally. The method also enables searches for directional correlations of cosmic rays with source candidates.

  6. The ultra-high energy cosmic rays image of Virgo A

    CERN Document Server

    Šmída, Radomír

    2015-01-01

    Arrival directions of ultra-high energy cosmic rays from the direction of ten brightest radio sources lying within 50 Mpc from our Galaxy were studied by using recent models of the largescale Galactic magnetic field. A detailed study, where also small-scale turbulent magnetic field component was implemented, is presented for the radiogalaxy Virgo A. This radiogalaxy is located far from the Galactic plane which leads to a unique image of this UHECR source candidate, if the flux is composed from a mixture of intermediate mass nuclei. We present a method suitable for identifying cosmic rays arriving from this close-by radiogalaxy.

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

    International Nuclear Information System (INIS)

    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.

  8. 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_\

  9. Energy spectrum of ultra high energy γ-rays from supernova

    International Nuclear Information System (INIS)

    If a newly born neutron star in SN1987A is a powerful injector of ultra high energy (UHE) protons, UHE γ-rays will be emitted by bombardment of supernova ejecta with these UHE particles. We compute energy spectrum of the UHE γ-rays generated by monoenergetic protons using Monte Carlo simulations at the period of high flux when the column density is 30∼100 g/cm2. If the column density of the ejecta is less than ∼100 g/cm2, low energy γ-rays do not increase as E-2, like the case for Cyg X-3, but they have much harder spectrum close to E-1. The expected numbers of PeV and TeV region γ-rays per hour are at least 0.16 counts (Lp/1041 ergs)(S/(50 m)2)(d/56 kpc)-2 and 132 counts (Lp/1041 ergs)(S/30000 m2)(d/56 kpc)-2 where Lp, S and d are the proton luminosity, the area of detectors, and the distance to LMC, respectively. (author)

  10. Measurement of the Energy Spectrum of Ultra-High Energy Cosmic Rays using Hybrid Data of the Pierre Auger Observatory

    OpenAIRE

    Schüssler, Fabian

    2009-01-01

    The subject of this thesis is the measurement of the energy spectrum of ultra-high energy cosmic rays from simultaneous observation of fluorescence and surface detectors of the Pierre Auger Observatory. Extending the nominal energy range of the Pierre Auger Observatory to lower energy, the hybrid energy spectrum above 10^{18} eV is measured. It shows a significant break of the power-law behavior at 10^{18.7} eV.

  11. Advanced Intermediate Temperature Sodium-Nickel Chloride Batteries with Ultra-High Energy Density

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Yong; Meinhardt, Kerry D.; Chang, Hee-Jung; Canfield, Nathan L.; Sprenkle, Vincent L.

    2016-02-11

    Here we demonstrate for the first time that planar Na-NiCl2 batteries can be operated at an intermediate temperature of 190°C with ultra-high energy density. A specific energy density of 350 Wh/kg, which is 3 times higher than that of conventional tubular Na-NiCl2 batteries operated at 280°C, was obtained for planar Na-NiCl2 batteries operated at 190°C over a long-term cell test (1000 cycles). The high energy density and superior cycle stability are attributed to the slower particle growth of the cathode materials (NaCl and Ni) at 190°C. The results reported in this work demonstrate that planar Na-NiCl2 batteries operated at an intermediate temperature could greatly benefit this traditional energy storage technology by improving battery energy density, cycle life and reducing material costs.

  12. Surface free energy of ultra-high molecular weight polyethylene modified by electron and gamma irradiation

    International Nuclear Information System (INIS)

    Surface free energy of biocompatible polymers is important factor which affects the surface properties such as wetting, adhesion and biocompatibility. In the present work, the change in the surface free energy of ultra-high molecular weight polyethylene (UHMWPE) samples, which is produced by electron beam and gamma ray irradiation were, investigated. Mechanism of the changes in surface free energy induced by irradiations of doses ranging from 25 to 500 kGy was studied. FTIR technique was applied for sample analysis. Contact angle measurements showed that wettability and surface free energy of samples have increased with increasing the irradiation dose, where the values of droplet contact angle of the samples decrease gradually with increasing the radiation dose. The increase in the wettability and surface free energy of the irradiated samples are attributed to formation of hydrophilic groups on the polymer surface by the oxidation, which apparently occurs by exposure of irradiated samples to the air.

  13. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    International Nuclear Information System (INIS)

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4–4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope – to validate the telescope design, and to demonstrate a large detector duty cycle – were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory. -- Highlights: • The MIDAS objective is to detect ultra high energy cosmic rays using microwaves. • GHz radiation could provide a powerful alternative to current detection methods. • The MIDAS prototype explores the potential of the microwave technique

  14. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Muñiz, J. [Universidad de Santiago de Compostela, Departamento de Física de Partículas, Campus Sur, Universidad, E-15782 Santiago de Compostela (Spain); Amaral Soares, E. [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Berlin, A.; Bogdan, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Boháčová, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic); Bonifazi, C. [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Carvalho, W.R. [Universidad de Santiago de Compostela, Departamento de Física de Partículas, Campus Sur, Universidad, E-15782 Santiago de Compostela (Spain); Mello Neto, J.R.T. de [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Facal San Luis, P., E-mail: facal@kicp.uchicago.edu [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); and others

    2013-08-11

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4–4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope – to validate the telescope design, and to demonstrate a large detector duty cycle – were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory. -- Highlights: • The MIDAS objective is to detect ultra high energy cosmic rays using microwaves. • GHz radiation could provide a powerful alternative to current detection methods. • The MIDAS prototype explores the potential of the microwave technique.

  15. Control of proton energy in ultra-high intensity laser-matter interaction

    International Nuclear Information System (INIS)

    Recent breakthroughs in short pulse laser technology resulted in (i) generation of ultra-high intensity (2x1022 W/cm2) and (ii) ultra-high contrast (10-11) short pulses at the Hercules facility of the University of Michigan, which has created the possibility of exploring a new regime of ion acceleration - the regime of Directed Coulomb Explosion (DCE). In this regime of sufficiently high laser intensities and target thicknesses approaching the relativistic plasma skin depth it is possible to expel electrons from the target focal volume by the laser's ponderomotive force allowing for direct laser ion acceleration combined with a Coulomb explosion. That results in greater than 100 MeV protons with a quasi-monoenergetic energy spectrum. The utilization of beam shaping, namely, the use of flat-top beams, leads to more efficient proton acceleration due to the increase of the longitudinal field. According to the results of 2D PIC simulations a 500 TW laser pulse with a super-Gaussian beam profile interacting with 0.1 micron aluminium-hydrogen foil is able to produce monoenergetic protons with the energy up to 240 MeV.

  16. Control of proton energy in ultra-high intensity laser-matter interaction

    Energy Technology Data Exchange (ETDEWEB)

    Maksimchuk, A; Bulanov, S S; Chvykov, V; Dollar, F; Kalintchenko, G; Matsuoka, T; Reed, S; Yanovsky, V; Krushelnick, K [FOCUS Center and Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, 48109 (United States); Brantov, A; Bychenkov, V Yu [P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Litzenberg, D, E-mail: tolya@umich.ed [Department of Radiation Oncology, University of Michigan, Ann Arbor, 48109 (United States)

    2010-08-01

    Recent breakthroughs in short pulse laser technology resulted in (i) generation of ultra-high intensity (2x10{sup 22} W/cm{sup 2}) and (ii) ultra-high contrast (10{sup -11}) short pulses at the Hercules facility of the University of Michigan, which has created the possibility of exploring a new regime of ion acceleration - the regime of Directed Coulomb Explosion (DCE). In this regime of sufficiently high laser intensities and target thicknesses approaching the relativistic plasma skin depth it is possible to expel electrons from the target focal volume by the laser's ponderomotive force allowing for direct laser ion acceleration combined with a Coulomb explosion. That results in greater than 100 MeV protons with a quasi-monoenergetic energy spectrum. The utilization of beam shaping, namely, the use of flat-top beams, leads to more efficient proton acceleration due to the increase of the longitudinal field. According to the results of 2D PIC simulations a 500 TW laser pulse with a super-Gaussian beam profile interacting with 0.1 micron aluminium-hydrogen foil is able to produce monoenergetic protons with the energy up to 240 MeV.

  17. 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.

  18. 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.

  19. Anisotropies of ultra-high energy cosmic ray nuclei diffusing from extragalactic sources

    CERN Document Server

    Harari, Diego; Roulet, Esteban

    2015-01-01

    We obtain the dipolar anisotropies in the arrival directions of ultra-high energy cosmic ray nuclei diffusing from nearby extragalactic sources. We consider mixed-composition scenarios in which different cosmic ray nuclei are accelerated up to the same maximum rigidity, so that $Eenergy. We adopt $E_\\text{max}^p\\simeq 6$ EeV so as to account for an increasingly heavier composition above the ankle. We obtain the anisotropies through Monte Carlo simulations that implement the cosmic ray diffusion in extragalactic turbulent fields as well as the effects of photo-disintegrations and other energy losses. Dipolar anisotropies at the level of 5 to 10\\% at energies $\\sim 10$~EeV are predicted for plausible values of the source density and magnetic fields.

  20. 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)

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

    International Nuclear Information System (INIS)

    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)

  2. 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.

  3. Energy ordering effects in the arrival directions of ultra-high energy cosmic rays measured by the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    The Pierre Auger Observatory is the world's largest experiment for the measurement of ultra-high energy cosmic rays (UHECRs). These UHECRs are assumed to be to be charged particles, and thus are deflected in cosmic magnetic fields. Recent results of the Pierre Auger Observatory addressing the complex of energy ordering of the UHECRs arrival directions are reviewed in this contribution. So far no significant energy ordering has been observed. (author)

  4. New Limits on the Ultra-high Energy Cosmic Neutrino Flux from the ANITA Experiment

    CERN Document Server

    Gorham, P; Beatty, J; Besson, D; Binns, W; Chen, C; Chen, P; Clem, J; Connolly, A; Dowkontt, P; DuVernois, M; Field, R; Goldstein, D; Goodhue, A; Hast, C; Hebert, C; Hoover, S; Israel, M; Kowalski, J; Learned, J; Liewer, K; Link, J; Lusczek, E; Matsuno, S; Mercurio, B; Miki, C; Miocinovic, P; Nam, J; Naudet, C; Nichol, R; Palladino, K; Reil, K; Romero-Wolf, A; Rosen, M; Ruckman, L; Saltzberg, D; Seckel, D; Varner, G; Walz, D; Wang, Y; Wu, F

    2008-01-01

    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 3 EeV. 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 ultra-high energy extensive air showers.

  5. The MIDAS experiment: A prototype for the microwave emission of Ultra-High Energy Cosmic Rays

    Science.gov (United States)

    Monasor, M.; Alekotte, I.; Alvarez-Muñiz, J.; Berlin, A.; Bertou, X.; Bodgan, M.; Bohacova, M.; Bonifazi, C.; Carvalho, W.; de Mello Neto, J. R. T.; Genat, J. F.; Facal San Luis, P.; Mills, E.; Rouille D'Orfeuil, B.; Wayne, S.; Reyes, L. C.; Santos, E. M.; Privitera, P.; Williams, C.; Zas, E.

    2011-06-01

    Recent measurements suggest that extensive air showers initiated by ultra-high energy cosmic rays (UHECR) emit signals in the microwave band of the electromagnetic spectrum caused by the collisions of the free-electrons with the atmospheric neutral molecules in the plasma produced by the passage of the shower. Such emission is isotropic and could allow the detection of air showers with 100% duty cycle and a calorimetric-like energy measurement, a significant improvement over current detection techniques. We have built MIDAS (MIcrowave Detection of Air Showers), a prototype of microwave detector, which consists of a 4.5 m diameter antenna with a cluster of 53 feed-horns in the 4 GHz range. The details of the prototype and first results will be presented.

  6. The MIDAS experiment: A prototype for the microwave emission of Ultra-High Energy Cosmic Rays

    CERN Document Server

    Monasor, M; Alvarez-Muniz, J; Berlin, A; Bertou, X; Bodgan, M; Bohacova, M; Bonifazi, C; Carvalho, W; Neto, J R T de Mello; Genat, J F; Luis, P Facal San; Mills, E; d’Orfeuil, B Rouille; Wayne, S; Reyes, L C; Santos, E M; Privitera, P; Williams, C; Zas, E

    2010-01-01

    Recent measurements suggest that extensive air showers initiated by ultra-high energy cosmic rays (UHECR) emit signals in the microwave band of the electromagnetic spectrum caused by the collisions of the free-electrons with the atmospheric neutral molecules in the plasma produced by the passage of the shower. Such emission is isotropic and could allow the detection of air showers with 100% duty cycle and a calorimetric-like energy measurement, a significant improvement over current detection techniques. We have built MIDAS (MIcrowave Detection of Air Showers), a prototype of microwave detector, which consists of a 4.5 m diameter antenna with a cluster of 53 feed-horns in the 4 GHz range. The details of the prototype and first results will be presented.

  7. The MIDAS experiment: A prototype for the microwave emission of Ultra-High Energy Cosmic Rays

    Energy Technology Data Exchange (ETDEWEB)

    Monasor, M. [Department of Astronomy and Astrophysics and Kavli Institute for Cosmological Physics, University of Chicago, 5640 S Ellis Ave, 60637 Chicago, IL (United States); Alekotte, I. [Centro Atomico Bariloche and Instituto Balseiro, San Carlos de Bariloche (Argentina); Alvarez-Muniz, J. [Universidad de Santiago de Compostela (Spain); Berlin, A. [Department of Astronomy and Astrophysics and Kavli Institute for Cosmological Physics, University of Chicago, 5640 S Ellis Ave, 60637 Chicago, IL (United States); Bertou, X. [Centro Atomico Bariloche and Instituto Balseiro, San Carlos de Bariloche (Argentina); Bodgan, M.; Bohacova, M. [Department of Astronomy and Astrophysics and Kavli Institute for Cosmological Physics, University of Chicago, 5640 S Ellis Ave, 60637 Chicago, IL (United States); Bonifazi, C. [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro (Brazil); Carvalho, W. [Universidad de Santiago de Compostela (Spain); Mello Neto, J.R.T. de [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro (Brazil); Genat, J.F.; Facal San Luis, P.; Mills, E.; Rouille d' Orfeuil, B.; Wayne, S.; Reyes, L.C. [Department of Astronomy and Astrophysics and Kavli Institute for Cosmological Physics, University of Chicago, 5640 S Ellis Ave, 60637 Chicago, IL (United States); Santos, E.M. [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro (Brazil); Privitera, P.; Williams, C. [Department of Astronomy and Astrophysics and Kavli Institute for Cosmological Physics, University of Chicago, 5640 S Ellis Ave, 60637 Chicago, IL (United States); Zas, E. [Universidad de Santiago de Compostela (Spain)

    2011-06-15

    Recent measurements suggest that extensive air showers initiated by ultra-high energy cosmic rays (UHECR) emit signals in the microwave band of the electromagnetic spectrum caused by the collisions of the free-electrons with the atmospheric neutral molecules in the plasma produced by the passage of the shower. Such emission is isotropic and could allow the detection of air showers with 100% duty cycle and a calorimetric-like energy measurement, a significant improvement over current detection techniques. We have built MIDAS (MIcrowave Detection of Air Showers), a prototype of microwave detector, which consists of a 4.5 m diameter antenna with a cluster of 53 feed-horns in the 4 GHz range. The details of the prototype and first results will be presented.

  8. 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...

  9. HERMES: Simulating the propagation of ultra-high energy cosmic rays

    Science.gov (United States)

    De Domenico, Manlio

    2013-08-01

    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 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 simulator.

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

    International Nuclear Information System (INIS)

    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

  11. Isotropy of ultra-high-energy cosmic rays and multiple supernova I galactic source

    Energy Technology Data Exchange (ETDEWEB)

    Colgate, S.A.

    1983-04-07

    Ultra-high-energy cosmic rays are usually associated with an extragalactic origin. Active galactic nuclei are an unlikely source because of photon drag. Here the possibility of supernova events are considered. The time spread of arrival of 10/sup 20/ eV protons is 100 to 400 years at 10 to 20 kpc and the angular spread is +-15 to +-30/sup 0/ depending upon the Galactic field configuration. The time spread is sufficient to include several to a dozen type I SN. This is enough events and angular spread to include the observed data. The concentration of the observed events at the galactic poles is contradictory. The flux is reasonable if the observed flux and slope at 10/sup 12/ to 10/sup 15/ eV is characteristic of the source(s) and confined at this energy for roughly 100 traversals of the Galaxy, or 3 x 10/sup 6/ years.

  12. Simulation of the Event Reconstruction of Ultra High Energy Cosmic Neutrinos with Askaryan Radio Array

    CERN Document Server

    Sun, Shang-Yu; Huang, Melin

    2010-01-01

    Askaryan Radio Array (ARA), a large-scale radio Cherenkov observatory which scientists propose to develop in Antarctica, aims at discovering the origin and evolution of the cosmic accelerators that produce the highest energy cosmic rays by means of observing the ultra high energy (UHE) cosmogenic neutrinos. To optimize ARA's angular resolution of the incoming UHE neutrinos, which is essential for pointing pack to its source, the relation between the reconstruction capabilities of ARA and its design is studied. It is found that with the noise effect taken into account, in order to make this neutrino angular resolution as good as possible and detection efficiency as high as possible, the optimal choice for ARA geometry would be the station spacing of 1.6 km and the antenna spacing of 40 m.

  13. Development and data analysis of a radio-detection of ultra high energy cosmic rays experiment

    International Nuclear Information System (INIS)

    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)

  14. Contribution to the identification of primary ultra high energy cosmic rays using the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    This research thesis focuses on an apparent mismatch noticed during experiments performed by the Pierre Auger Observatory on ultra-high energy cosmic rays (UHECR) and mass composition. Surface detectors are used to detect the Cherenkov light emitted by particle flurry, and record data in fast analog/digital converters in order to identify the presence of sudden jumps with that of muons. The author studied the separation between light (protons) and heavy (iron) primers which can be expected from the total jump value. An energy analysis in then applied to the study of detected flurries which confirmed the mismatch with the predictions of flurry development models. The jump method is applied to UHECRs pointing towards Cen A. The second part of the thesis reports the development of a simplified simulation code (simulation of electromagnetic and hadronic showers)

  15. On ultra-high energy cosmic ray acceleration at the termination shock of young pulsar winds

    Science.gov (United States)

    Lemoine, Martin; Kotera, Kumiko; Pétri, Jérôme

    2015-07-01

    Pulsar wind nebulae (PWNe) are outstanding accelerators in Nature, in the sense that they accelerate electrons up to the radiation reaction limit. Motivated by this observation, this paper examines the possibility that young pulsar wind nebulae can accelerate ions to ultra-high energies at the termination shock of the pulsar wind. We consider here powerful PWNe, fed by pulsars born with ~ millisecond periods. Assuming that such pulsars exist, at least during a few years after the birth of the neutron star, and that they inject ions into the wind, we find that protons could be accelerated up to energies of the order of the Greisen-Zatsepin-Kuzmin cut-off, for a fiducial rotation period P ~ 1 msec and a pulsar magnetic field Bstar ~ 1013 G, implying a fiducial wind luminosity Lp ~ 1045 erg/s and a spin-down time tsd ~ 3× 107 s. The main limiting factor is set by synchrotron losses in the nebula and by the size of the termination shock; ions with Z>= 1 may therefore be accelerated to even higher energies. We derive an associated neutrino flux produced by interactions in the source region. For a proton-dominated composition, our maximum flux lies slightly below the 5-year sensitivity of IceCube-86 and above the 3-year sensitivity of the projected Askaryan Radio Array. It might thus become detectable in the next decade, depending on the exact level of contribution of these millisecond pulsar wind nebulae to the ultra-high energy cosmic ray flux.

  16. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    Science.gov (United States)

    Alvarez-Muñiz, J.; Amaral Soares, E.; Berlin, A.; Bogdan, M.; Boháčová, M.; Bonifazi, C.; Carvalho, W. R.; de Mello Neto, J. R. T.; Facal San Luis, P.; Genat, J. F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.; Ramos de Castro, A.; Reyes, L. C.; Richardson, M.; Rouille d'Orfeuil, B.; Santos, E. M.; Wayne, S.; Williams, C.; Zas, E.; Zhou, J.

    2013-08-01

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4-4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope - to validate the telescope design, and to demonstrate a large detector duty cycle - were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory.

  17. Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic Ray Propagation

    International Nuclear Information System (INIS)

    We discuss the influence of large scale cosmic magnetic fields on the propagation of hadronic cosmic rays above 1019 eV based on large scale structure simulations. Our simulations suggest that rather substantial deflection up to several tens of degrees at 1020 eV are possible for nucleon primaries. Further, spectra and composition of cosmic rays from individual sources can depend on magnetic fields surrounding these sources in intrinsically unpredictable ways. This is true even if deflection from such individual sources is small. We conclude that the influence of large scale cosmic magnetic fields on ultra-high energy cosmic ray propagation is currently hard to quantify. We discuss possible reasons for discrepant results of simulations by Dolag et al. which predict deflections of at most a few degrees for nucleons. We finally point out that even in these latter simulations a possible heavy component would in general suffer substantial deflection

  18. Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic Ray Propagation

    Energy Technology Data Exchange (ETDEWEB)

    Sigl, Guenter [GReCO, Institut d' Astrophysique de Paris, C.N.R.S., 98 bis boulevard Arago, F-75014 Paris (France); Federation de Recherche Astroparticule et Cosmologie, Universite Paris 7, 2 place Jussieu, 75251 Paris, Cedex 05 (France); Miniati, Francesco; Ensslin, Torsten A. [Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany)

    2004-11-15

    We discuss the influence of large scale cosmic magnetic fields on the propagation of hadronic cosmic rays above 10{sup 19} eV based on large scale structure simulations. Our simulations suggest that rather substantial deflection up to several tens of degrees at 10{sup 20} eV are possible for nucleon primaries. Further, spectra and composition of cosmic rays from individual sources can depend on magnetic fields surrounding these sources in intrinsically unpredictable ways. This is true even if deflection from such individual sources is small. We conclude that the influence of large scale cosmic magnetic fields on ultra-high energy cosmic ray propagation is currently hard to quantify. We discuss possible reasons for discrepant results of simulations by Dolag et al. which predict deflections of at most a few degrees for nucleons. We finally point out that even in these latter simulations a possible heavy component would in general suffer substantial deflection.

  19. Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic Ray Propagation

    Science.gov (United States)

    Sigl, Günter; Miniati, Francesco; Enßlin, Torsten A.

    2004-11-01

    We discuss the influence of large scale cosmic magnetic fields on the propagation of hadronic cosmic rays above 1019 eV based on large scale structure simulations. Our simulations suggest that rather substantial deflection up to several tens of degrees at 1020 eV are possible for nucleon primaries. Further, spectra and composition of cosmic rays from individual sources can depend on magnetic fields surrounding these sources in intrinsically unpredictable ways. This is true even if deflection from such individual sources is small. We conclude that the influence of large scale cosmic magnetic fields on ultra-high energy cosmic ray propagation is currently hard to quantify. We discuss possible reasons for discrepant results of simulations by Dolag et al. which predict deflections of at most a few degrees for nucleons. We finally point out that even in these latter simulations a possible heavy component would in general suffer substantial deflection.

  20. Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic Ray Propagation

    CERN Document Server

    Sigl, G; Ensslin, T A; Sigl, Guenter; Miniati, Francesco; Ensslin, Torsten

    2004-01-01

    We discuss the influence of large scale cosmic magnetic fields on the propagation of hadronic cosmic rays above 10^19 eV based on large scale structure simulations. Our simulations suggest that rather substantial deflection up to several tens of degrees at 10^20 eV are possible for nucleon primaries. Further, spectra and composition of cosmic rays from individual sources can depend on magnetic fields surrounding these sources in intrinsically unpredictable ways. This is true even if deflection from such individual sources is small. We conclude that the influence of large scale cosmic magnetic fields on ultra-high energy cosmic ray propagation is currently hard to quantify. We discuss possible reasons for discrepant results of simulations by Dolag et al. which predict deflections of at most a few degrees for nucleons. We finally point out that even in these latter simulations a possible heavy component would in general suffer substantial deflection.

  1. 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.

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

    Science.gov (United States)

    Fujii, T.; Malacari, M.; 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.

    2016-02-01

    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 Telescopes (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 kilometers as well as 16 highly significant UHECR shower candidates.

  3. Search for Cross-Correlations of Ultra--High-Energy Cosmic Rays with BL Lacertae Objects

    CERN Document Server

    Abbasi, R U; Amman, J F; Archbold, G; Atkins, R; Bellido, J A; Belov, K; Belz, J W; Ben-Zvi, S Y; Bergman, D R; Burt, G W; Cao, Z; Clay, R W; Connolly, B C; Deng, W; Dawson, B R; Fedorova, Y; Findlay, J; Finley, C B; Hanlon, W F; Hoffman, C M; Hughes, G A; Holzscheiter, M H; Hüntemeyer, P; Jui, C C H; Kim, K; Kirn, M A; Loh, E C; Maestas, M M; Manago, N; Marek, L J; Martens, K; Matthews, J A J; Matthews, J N; O'Neill, A; Painter, C A; Perera, L P; Reil, K; Riehle, R; Roberts, M; Sasaki, M; Schnetzer, S R; Simpson, K M; Sinnis, G; Smith, J D; Snow, R; Sokolsky, P; Song, C; Springer, R W; Stokes, B T; Thomas, J R; Thomas, S B; Thomson, G B; Tupa, D; Westerhoff, S; Wiencke, L R; Zech, A

    2005-01-01

    Data taken in stereo mode by the High Resolution Fly's Eye (HiRes) air fluorescence experiment are analyzed to search for correlations between the arrival directions of ultra--high-energy cosmic rays with the positions of BL Lacertae objects. Several previous claims of significant correlations between BL Lacs and cosmic rays observed by other experiments are tested. These claims are not supported by the HiRes data. However, we verify a recent analysis of correlations between HiRes events and a subset of confirmed BL Lacs from the 10th Veron Catalog, and we study this correlation in detail. Due to the a posteriori nature of the search, the significance level cannot be reliably estimated and the correlation must be tested independently before any claim can be made. We identify the precise hypotheses that will be tested with statistically independent data.

  4. 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.

  5. 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.

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

    International Nuclear Information System (INIS)

    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

  7. CRPropa 3 - a Public Astrophysical Simulation Framework for Propagating Extraterrestrial Ultra-High Energy Particles

    CERN Document Server

    Batista, Rafael Alves; Erdmann, Martin; Kampert, Karl-Heinz; Kuempel, Daniel; Müller, Gero; Sigl, Guenter; van Vliet, Arjen; Walz, David; Winchen, Tobias

    2016-01-01

    We present the simulation framework CRPropa version 3 designed for efficient development of astrophysical predictions for ultra-high energy particles. Users can assemble modules of the most relevant propagation effects in galactic and extragalactic space, include their own physics modules with new features, and receive on output primary and secondary cosmic messengers including nuclei, neutrinos and photons. In extension to the propagation physics contained in a previous CRPropa version, the new version facilitates high-performance computing and comprises new physical features such as an interface for galactic propagation using lensing techniques, an improved photonuclear interaction calculation, and propagation in time dependent environments to take into account cosmic evolution effects in anisotropy studies and variable sources. First applications using highlighted features are presented as well.

  8. Search for ultra-high-energy radiation from γ-ray bursts

    International Nuclear Information System (INIS)

    Using data from the CYGNUS extensive air shower array, we have searched for evidence of emission of ultra-high-energy radiation coincident with γ-ray bursts observed by the BATSE instrument on the Compton Gamma-Ray Observatory. No statistically significant excess was found for any point in the sky within 4σ of BATSE's best location coordinates for any of the 56 bursts examined. Furthermore, no events were seen in the 2.2 degree radius circular bin surrounding γ-ray burst GRB 920720, whose location was determined accurately by the Compton/Ulysses/PVO Interplanetary Network of satellites. Flux upper limits depend greatly on the actual zenith angle of the burst. Typical fluence upper limits above 100 TeV are ∼10-6 erg cm-2. The fluence upper limits for GRB 920720 is 2 x 10-6 erg cm-2

  9. 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.

  10. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    CERN Document Server

    Alvarez-Muñiz, J; Berlin, A; Bogdan, M; Boháčová, M; Bonifazi, C; Carvalho, W R; Neto, J R T de Mello; Luis, P Facal San; Genat, J F; Hollon, N; Mills, E; Monasor, M; Privitera, P; de Castro, A Ramos; Reyes, L C; d'Orfeuil, B Rouille; Santos, E M; Wayne, S; Williams, C; Zas, E; Zhou, J

    2012-01-01

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4 -- 4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope - to validate the telescope design, and to demonstrate a large detector duty cycle - were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory.

  11. High energy mechanical milling of ultra-high molecular weight polyethylene (UHMWPE)

    International Nuclear Information System (INIS)

    Ultra-high molecular weight polyethylene (UHMWPE) is a polyethylene with a very long chain, which provides excellent features, but makes the processing difficult due to high melt viscosity. Many studies intend to found out means to make its processing easier. Recently, the high energy mechanical milling has been used for polymeric materials and it was detected that physical and chemical changes occur during milling. In such case, powder of UHMWPE was milled in three types of mills: SPEX, attritor e planetary, in different times of milling. The milling temperatures were measured during processing. The polymer was characterized by SEM, DSC and XRD, and the deconvolution of x-ray diffractograms was made. Thus, it was observed that the material processed in attritor mill showed larger phase transformation from orthorhombic to monoclinic. This is most likely due to the smaller milling temperature of attritor mill when compared with the other two mills and the high shear force generated during milling. (author)

  12. Complementary research ability of ground- and space-based detectors of ultra high energy cosmic rays

    International Nuclear Information System (INIS)

    In comparison of ground- and space-based optical detectors of ultra high energy cosmic rays (UHECR) the space-based detectors have the advantage of registering EAS, initiated by UHECR particles, at a much larger area of the atmosphere. They also have the advantages of observing EAS in a wide range of atmosphere depth including near-horizontal EAS, initiated by neutrino at depths >1000 g cm-2. Ground-based particle detector arrays have the advantages of taking data on EAS parameters, sensitive to a primary particle mass, not determined by space detectors. Particle detectors having 100% duty cycle observe a specific UHECR source longer than the space detector with the same geometrical factor

  13. Ultra-high energy cosmic rays: The annihilation of super-heavy relics

    International Nuclear Information System (INIS)

    We investigate the possibility that ultra-high energy cosmic rays (UHECRs) originate from the annihilation of relic superheavy (SH) dark matter in the Galactic halo. In order to fit the data on UHECRs, a cross section of Aν> ∼ 10-26cm2(Mx/1012 GeV)((3)/(2)) is required if the SH dark matter follows a Navarro-Frenk-White (NFW) density profile. This would require extremely large-l contributions to the annihilation cross section. An interesting finding of our calculation is that the annihilation in sub-galactic clumps of dark matter dominates over the annihilations in the smooth dark matter halo, thus implying much smaller values of the cross section needed to explain the observed fluxes of UHECRs

  14. A search for ultra-high energy counterparts to gamma-ray bursts

    CERN Document Server

    Plunkett, S P; McBreen, B; Hurley, K J; O'Sullivan, C T

    1995-01-01

    A small air shower array operating over many years has been used to search for ultra-high energy (UHE) gamma radiation (\\geq 50 TeV) associated with gamma-ray bursts (GRBs) detected by the BATSE instrument on the Compton Gamma-Ray Observatory (CGRO). Upper limits for a one minute interval after each burst are presented for seven GRBs located with zenith angles \\theta < 20^{\\circ}. A 4.3\\sigma excess over background was observed between 10 and 20 minutes following the onset of a GRB on 11 May 1991. The confidence level that this is due to a real effect and not a background fluctuation is 99.8\\%. If this effect is real then cosmological models are excluded for this burst because of absorption of UHE gamma rays by the intergalactic radiation fields.

  15. Design of ultra-high-energy, high-resolution and high-sensitivity collimators for gamma cameras

    International Nuclear Information System (INIS)

    Recently, small object imaging using positron emitters, such as fluorine-18-2-deoxyglucose, has focused on basic nuclear medicine techniques. We have designed and developed ultra-high-energy high-resolution collimators for small object imaging. Firstly, we produced an ultra-high-energy pinhole collimator. The thickness of the lead shielding was 30 mm. The pinhole diameter of knife-edge aperture was 0.6 mm. The acceptance angle was 13 deg. This cylinder was equipped with a non-collimator gamma camera at a distance of 30.5 cm. The radius of rotation was 6 cm and the magnification was 5.1 times. In simulation calculations, as the pinhole-object distance decreased, geometric sensitivity increased geometrically. However, as the pinhole-object-distance decreased, field-of-view (FOV) decreased linearly. Spatial resolution was measured using a line source of 18F and was 2.4 mm at full-width-at-half-maximum and 9.5 mm at full-width-at-tenth-maximum. The sensitivity of the system was 6.8 counts sec-1 MBq-1 using a point source of 18F. In addition, sensitivity at the rim of FOV was lower than that at the center. Next, we designed an ultra-high-energy converging collimator. It was found that the converging collimator had uniform sensitivity over the FOV. Also, the FOV at smaller collimator-object distances was not as restricted as the ultra-high-energy pinhole collimator. Thus, we demonstrated that high-resolution images for ultra-high-energy imaging could be acquired using the pinhole collimator. Moreover, we believe that the ultra-high-energy converging collimator could be available for a clinical study. (author)

  16. 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...

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

    International Nuclear Information System (INIS)

    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) (Schmidt et al., 2002) 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 (Derbenev et al., 1978) 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 during synchrotron oscillations at current energies, evolves into ''uncorrelated'' crossing of spin resonances at ultra-high energies.

  18. Advanced intermediate temperature sodium-nickel chloride batteries with ultra-high energy density.

    Science.gov (United States)

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Y; Meinhardt, Kerry D; Chang, Hee Jung; Canfield, Nathan L; Sprenkle, Vincent L

    2016-01-01

    Sodium-metal halide batteries have been considered as one of the more attractive technologies for stationary electrical energy storage, however, they are not used for broader applications despite their relatively well-known redox system. One of the roadblocks hindering market penetration is the high-operating temperature. Here we demonstrate that planar sodium-nickel chloride batteries can be operated at an intermediate temperature of 190 °C with ultra-high energy density. A specific energy density of 350 Wh kg(-1), higher than that of conventional tubular sodium-nickel chloride batteries (280 °C), is obtained for planar sodium-nickel chloride batteries operated at 190 °C over a long-term cell test (1,000 cycles), and it attributed to the slower particle growth of the cathode materials at the lower operating temperature. Results reported here demonstrate that planar sodium-nickel chloride batteries operated at an intermediate temperature could greatly benefit this traditional energy storage technology by improving battery energy density, cycle life and reducing material costs. PMID:26864635

  19. Advanced intermediate temperature sodium-nickel chloride batteries with ultra-high energy density

    Science.gov (United States)

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Y.; Meinhardt, Kerry D.; Chang, Hee Jung; Canfield, Nathan L.; Sprenkle, Vincent L.

    2016-02-01

    Sodium-metal halide batteries have been considered as one of the more attractive technologies for stationary electrical energy storage, however, they are not used for broader applications despite their relatively well-known redox system. One of the roadblocks hindering market penetration is the high-operating temperature. Here we demonstrate that planar sodium-nickel chloride batteries can be operated at an intermediate temperature of 190 °C with ultra-high energy density. A specific energy density of 350 Wh kg-1, higher than that of conventional tubular sodium-nickel chloride batteries (280 °C), is obtained for planar sodium-nickel chloride batteries operated at 190 °C over a long-term cell test (1,000 cycles), and it attributed to the slower particle growth of the cathode materials at the lower operating temperature. Results reported here demonstrate that planar sodium-nickel chloride batteries operated at an intermediate temperature could greatly benefit this traditional energy storage technology by improving battery energy density, cycle life and reducing material costs.

  20. 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.

  1. Advanced intermediate temperature sodium–nickel chloride batteries with ultra-high energy density

    Science.gov (United States)

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Y.; Meinhardt, Kerry D.; Chang, Hee Jung; Canfield, Nathan L.; Sprenkle, Vincent L.

    2016-01-01

    Sodium-metal halide batteries have been considered as one of the more attractive technologies for stationary electrical energy storage, however, they are not used for broader applications despite their relatively well-known redox system. One of the roadblocks hindering market penetration is the high-operating temperature. Here we demonstrate that planar sodium–nickel chloride batteries can be operated at an intermediate temperature of 190 °C with ultra-high energy density. A specific energy density of 350 Wh kg−1, higher than that of conventional tubular sodium–nickel chloride batteries (280 °C), is obtained for planar sodium–nickel chloride batteries operated at 190 °C over a long-term cell test (1,000 cycles), and it attributed to the slower particle growth of the cathode materials at the lower operating temperature. Results reported here demonstrate that planar sodium–nickel chloride batteries operated at an intermediate temperature could greatly benefit this traditional energy storage technology by improving battery energy density, cycle life and reducing material costs. PMID:26864635

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

    Energy Technology Data Exchange (ETDEWEB)

    Baerwald, Philipp [Wuerzburg Univ. (Germany). Inst. fuer Theoretische Physik und Astrophysik; Pennsylvania State Univ., University Park, PA (United States). Dept. of Astronomy and Astrophysics; Pennsylvania State Univ., University Park, PA (United States). Dept. of Physics; Pennsylvania State Univ., University Park, PA (United States). Center for Particle and Gravitational Astrophysics; Pennsylvania State Univ., University Park, PA (United States). Inst. for Gravitation and the Cosmos; Bustamante, Mauricio; Winter, Walter [Wuerzburg Univ. (Germany). Inst. fuer Theoretische Physik und Astrophysik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2014-07-15

    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 corresponding neutrino bound. On the other hand, GRBs may account for the UHECRs in the ankle transition model if cosmic rays leak out from the source at the highest energies. In that case, we demonstrate that future neutrino observations can efficiently test most of the parameter space - unless the baryonic loading is much larger than previously anticipated.

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

    International Nuclear Information System (INIS)

    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 corresponding neutrino bound. On the other hand, GRBs may account for the UHECRs in the ankle transition model if cosmic rays leak out from the source at the highest energies. In that case, we demonstrate that future neutrino observations can efficiently test most of the parameter space - unless the baryonic loading is much larger than previously anticipated.

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. Search for Ultra-High Energy Tau Neutrinos in IceCube

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dawn

    2014-08-15

    The IceCube Neutrino Observatory at the geographic South Pole was designed with the primary goal of discovering high energy neutrinos from astrophysical objects such as active galactic nuclei and gamma ray bursts. IceCube completed construction in 2010 and has been collecting data throughout the construction phase. IceCube is sensitive to all three flavors of neutrinos, each of which has a distinct topological signature within the detector. At sufficiently high energies, the tau neutrino signature is a “double bang” from the charged current interaction of the neutrino and the decay of the tau lepton. At high energies, the tau neutrino has negligible background and would be an intriguing astrophysical signature. A dedicated search for ultra-high energy tau neutrinos (340 TeV–200 PeV) was performed using data from the partial IceCube detector, yielding a 90% CL upper limit of E{sub ν}{sup 2}Φ{sub 90}(ν{sub x})<16.3×10{sup −8}GeVcm{sup −2}sr{sup −1}s{sup −1} on a diffuse astrophysical flux of UHE neutrinos.

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

    Science.gov (United States)

    Ackermann, M.; Adams, J.; 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.; Demirörs, L.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Diaz-Velez, 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.; Groß, 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.; Hülß, 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.; Köpke, L.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Kuehn, K.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Lauer, R.; Leich, H.; Leier, D.; Liubarsky, I.; Lundberg, J.; Lünemann, J.; Madsen, J.; Maruyama, R.; Mase, K.; Matis, H. S.; McCauley, T.; McParland, C. P.; Meagher, K.; Meli, A.; Messarius, T.; Mészáros, P.; Miyamoto, H.; Montaruli, T.; Morey, A.; Morse, R.; Movit, S. M.; Münich, K.; Nahnhauer, R.; Nam, J. W.; Nießen, P.; Nygren, D. R.; Olivas, A.; Ono, M.; Patton, S.; Pérez de los 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, O.; Tepe, A.; Thollander, L.; Tilav, S.; Tluczykont, M.; Toale, P. A.; Tosi, D.; Turčan, 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.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, X. W.; Yodh, G.; Yoshida, S.; Zornoza, J. D.; IceCube Collaboration

    2008-03-01

    A search for diffuse neutrinos with energies in excess of 105 GeV is conducted with AMANDA-II data recorded between 2000 and 2002. Above 107 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 E2Φ90% CL < 2.7 × 10-7 GeV cm-2 s-1 sr-1 valid over the energy range of 2 × 105 to 109 GeV. A number of models that predict neutrino fluxes from active galactic nuclei are excluded at the 90% confidence level.

  10. Ultra High Energy Cosmic Ray and UHE Neutrino-Z Showering in Dark Halos

    CERN Document Server

    Fargion, D; Grossi, M; De Santis, M; Melé, Barbara; Fargion, Daniele; Mele, Barbara

    2001-01-01

    he Ultra High Energy Cosmic Ray (UHECR), by UHE neutrino-relic neutrino--Z showering in Hot Dark Halos (HDM), shows an energy spectra, an anisotropy following the relic neutrino masses and clustering in dark halo. The lighter are the relic neutrinos masses, the higher their corresponding Z resonance energy peaks. A twin light neutrino mass splitting may reflect a twin Z resonance and a complex UHECR spectra modulation a twin bump at at highest GZK energy cut-off. Each possible neutrino mass associates a characteristic dark halo size (galactic, local, super cluster) and its anisotropy due to our peculiar position within that dark matter distribution. The expected Z or WW,ZZ showering into proton-anti proton and neutron-anti neutron should correspond to peculiar clustering in observed UHECR at 10^{19},2 10^{19}, 4 10^{19}. A neutrino light HDM halo around a Mpc will allow to the UHECR n - bar{n} secondary component at E_n> 10^{20} eV (due to Z decay) to arise playing a role comparable with the charged p-bar{p} ...

  11. Search for Ultra-High Energy Tau Neutrinos in IceCube

    International Nuclear Information System (INIS)

    The IceCube Neutrino Observatory at the geographic South Pole was designed with the primary goal of discovering high energy neutrinos from astrophysical objects such as active galactic nuclei and gamma ray bursts. IceCube completed construction in 2010 and has been collecting data throughout the construction phase. IceCube is sensitive to all three flavors of neutrinos, each of which has a distinct topological signature within the detector. At sufficiently high energies, the tau neutrino signature is a “double bang” from the charged current interaction of the neutrino and the decay of the tau lepton. At high energies, the tau neutrino has negligible background and would be an intriguing astrophysical signature. A dedicated search for ultra-high energy tau neutrinos (340 TeV–200 PeV) was performed using data from the partial IceCube detector, yielding a 90% CL upper limit of Eν2Φ90(νx)<16.3×10−8GeVcm−2sr−1s−1 on a diffuse astrophysical flux of UHE neutrinos

  12. Cuts and penalties: comment on "The clustering of ultra-high energy cosmic rays and their sources"

    OpenAIRE

    Tinyakov, P.; I. Tkachev(CERN)

    2003-01-01

    In a series of papers we have found statistically significant correlations between arrival directions of ultra-high energy cosmic rays and BL Lacertae objects. Recently, our calculations were partly repeated by Evans, Ferrer and Sarkar with different conclusions. We demonstrate that the criticism of Evans, Ferrer and Sarkar is incorrect. We also present the details of our method.

  13. Small-x Parton Densities from HERA and the Ultra-High Energy Neutrino-Nucleon Cross Sections

    OpenAIRE

    Gandhi, Raj; Quigg, Chris; Reno, M. H.; Sarcevic, Ina

    1995-01-01

    In light of recent measurements of the nucleon structure function in the small-$x$ deep-inelastic regime at HERA and the consequently improved theoretical understanding of the quark distributions in this range of parton fractional momentum, we present new results for the neutrino-nucleon cross section at ultra high energies, up to $ E_{\

  14. Optimized trigger for ultra-high-energy cosmic-ray and neutrino observations with the low frequency radio array

    International Nuclear Information System (INIS)

    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 efficient trigger implementation for LOFAR optimized for the observation of short radio pulses.

  15. 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.

  16. The construction, characterization and use of a low-energy, ultra-high vacuum compatible, metal ion source

    International Nuclear Information System (INIS)

    The design, operation, and use of a low-cost, single grid, electron impact, ultra-high vacuum (UHV) compatible, low-to-medium energy (50-500 eV) ion source capable of operating with medium vapour pressure source material such as Indium is described. (author)

  17. 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...

  18. 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...

  19. 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 ...

  20. Ultra high energy cosmic rays: implications of Auger data for source spectra and chemical composition

    International Nuclear Information System (INIS)

    We use a kinetic-equation approach to describe the propagation of ultra high energy cosmic ray protons and nuclei and calculate the expected spectra and mass composition at the Earth for different assumptions on the source injection spectra and chemical abundances. When compared with the spectrum, the elongation rate Xmax(E) and dispersion σ(Xmax) as observed with the Pierre Auger Observatory, several important consequences can be drawn: a) the injection spectra of nuclei must be very hard, ∼ E-γ with γ∼ 1- 1.6; b) the maximum energy of nuclei of charge Z in the sources must be ∼ 5Z× 1018 eV, thereby not requiring acceleration to extremely high energies; c) the fit to the Auger spectrum can be obtained only at the price of adding an ad hoc light extragalactic component with a steep injection spectrum ∼ E-2.7). In this sense, at the ankle EA≈ 5× 1018 eV) all the components are of extragalactic origin, thereby suggesting that the transition from Galactic to extragalactic cosmic rays occurs below the ankle. Interestingly, the additional light extragalactic component postulated above compares well, in terms of spectrum and normalization, with the one recently measured by KASCADE-Grande

  1. SEN Ultra-High Energy Implanter (UHE) Developed for Next Generation Image Sensors

    International Nuclear Information System (INIS)

    The UHE is an ultra-high energy implanter developed by SEN Corporation. It was derived from the NV-GSD-HE3 by adding six RF resonators to the beam line. This extends performance so that singly charged boron ions can reach 2 MeV with beam current of 0.75 mA. The maximum energy for triple charged boron is 5 MeV with beam current of 1pμA. For phosphorus ions, the UHE can accelerate doubly charged ions up to 4.4 MeV with beam current of 0.35 mA and quadruply charged ions up to 8 MeV with beam current of 1 pμA. The primary application of the UHE is the image sensor market where it is used to increase the depth of CCD photodiodes into the surface of the wafer and thereby permit higher pixel density for image sensors. The second purpose is to improve productivity for relatively high boron doses at energies around 3 MeV. In order to address certain CCD defects, the system includes a state-of-the-art beam profile controller which allows optimization of implant damage and micro-uniformity. The ULE is currently used in production of high-end CCD's.

  2. 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...

  3. Ultra high energy cosmic rays: implications of Auger data for source spectra and chemical composition

    Energy Technology Data Exchange (ETDEWEB)

    Aloisio, R.; Blasi, P. [INAF/Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5—50125 Firenze (Italy); Berezinsky, V., E-mail: aloisio@arcetri.astro.it, E-mail: berezinsky@lngs.infn.it, E-mail: blasi@arcetri.astro.it [Gran Sasso Science Institute (INFN), viale F. Crispi 7, 67100 L' Aquila (Italy)

    2014-10-01

    We use a kinetic-equation approach to describe the propagation of ultra high energy cosmic ray protons and nuclei and calculate the expected spectra and mass composition at the Earth for different assumptions on the source injection spectra and chemical abundances. When compared with the spectrum, the elongation rate X{sub max}(E) and dispersion σ(X{sub max}) as observed with the Pierre Auger Observatory, several important consequences can be drawn: a) the injection spectra of nuclei must be very hard, ∼ E{sup -γ} with γ∼ 1- 1.6; b) the maximum energy of nuclei of charge Z in the sources must be ∼ 5Z× 10{sup 18} eV, thereby not requiring acceleration to extremely high energies; c) the fit to the Auger spectrum can be obtained only at the price of adding an ad hoc light extragalactic component with a steep injection spectrum ∼ E{sup -2.7}). In this sense, at the ankle E{sub A}≈ 5× 10{sup 18} eV) all the components are of extragalactic origin, thereby suggesting that the transition from Galactic to extragalactic cosmic rays occurs below the ankle. Interestingly, the additional light extragalactic component postulated above compares well, in terms of spectrum and normalization, with the one recently measured by KASCADE-Grande.

  4. The First Limits on the Ultra-high Energy Neutrino Fluence from Gamma-ray Bursts

    CERN Document Server

    Vieregg, A G; Allison, P; Baughman, B M; Beatty, J J; Belov, K; Besson, D Z; Bevan, S; Binns, W R; Chen, C; Chen, P; Clem, J M; Connolly, A; Detrixhe, M; De Marco, D; Dowkontt, P F; DuVernois, M; Gorham, P W; Grashorn, E W; Hill, B; Hoover, S; Huang, M; Israel, M H; Javaid, A; Liewer, K M; Matsuno, S; Mercurio, B C; Miki, C; Mottram, M; Nam, J; Nichol, R J; Romero-Wolf, A; Ruckman, L; Saltzberg, D; Seckel, D; Varner, G S; Wang, Y

    2011-01-01

    We set the first limits on the ultra-high energy (UHE) neutrino fluence at energies greater than 10^9 GeV from gamma-ray bursts (GRBs) based on data from the second flight of the ANtarctic Impulsive Transient Antenna (ANITA). During the 31 day flight of ANITA-II, 26 GRBs were recorded by Swift or Fermi. Of these, we analyzed the 12 GRBs which occurred during quiet periods when the payload was away from anthropogenic activity. In a blind analysis, we observe 0 events on a total background of 0.0044 events in the combined prompt window for all 12 low-background bursts. We also observe 0 events from the remaining 14 bursts. We place a 90% confidence level limit on the E^-4 prompt neutrino fluence of 2.5x10^17 GeV^3/cm^2 between 10^8 and 10^12 GeV from GRB090107A. This is the first reported limit on the UHE neutrino fluence from GRBs above 10^9 GeV, and the strongest limit above 10^8 GeV.

  5. 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.)

  6. Magnetic Deflections of Ultra-High Energy Cosmic Rays from Centaurus A

    CERN Document Server

    Keivani, Azadeh; Sutherland, Michael

    2014-01-01

    We present the results of a study that simulates trajectories of ultra-high energy cosmic rays from Centaurus A to Earth, for particle rigidities from $E/Z = 2$ EV to 100 EV, i.e., covering the possibility of primary particles as heavy as Fe nuclei with energies exceeding 50 EeV. The Galactic magnetic field is modeled using the recent work of Jansson and Farrar (JF12) which fitted its parameters to match extragalactic Faraday rotation measures and WMAP7 synchrotron emission maps. We include the random component of the GMF using the JF12 3D model for $B_{\\rm rand}(\\vec{r})$ and explore the impact of different random realizations, coherence length and other features on cosmic ray deflections. Gross aspects of the arrival direction distribution such as mean deflection and the RMS dispersion depend mainly on rigidity and differ relatively little from one realization to another. However different realizations exhibit non-trivial substructure whose specific features vary considerably from one realization to another...

  7. Photon air showers at ultra-high energy and the photonuclear cross-section

    CERN Document Server

    Risse, M; Engel, R; Gora, D; Heck, D; Pekala, J; Wilczynska, B; Wilczynski, H

    2006-01-01

    Experimental conclusions from air shower observations on cosmic-ray photons above 10^19 eV are based on the comparison to detailed shower simulations. For the calculations, the photonuclear cross-section needs to be extrapolated over several orders of magnitude in energy. The uncertainty from the cross-section extrapolation translates into an uncertainty of the predicted shower features for primary photons and, thus, into uncertainties for a possible data interpretation. After briefly reviewing the current status of ultra-high energy photon studies, the impact of the uncertainty of the photonuclear cross-section for shower calculations is investigated. Estimates for the uncertainties in the main shower observables are provided. Photon discrimination is shown to be possible even for rapidly rising cross-sections. When photon-initiated showers are identified, it is argued that the sensitivity of photon shower observables to the photonuclear cross-section can in turn be exploited to constrain the cross-section a...

  8. Statistical Significance of Small Scale Anisotropy in Arrival Directions of Ultra-High Energy Cosmic Rays

    CERN Document Server

    Yoshiguchi, H; Sato, K; Yoshiguchi, Hiroyuki; Nagataki, Shigehiro; Sato, Katsuhiko

    2004-01-01

    Recently, the High Resolution Fly's Eye (HiRes) experiment claims that there is no small scale anisotropy in the arrival distribution of ultra-high energy cosmic rays (UHECRs) above $E>10^{19}$ eV contrary to the Akeno Giant Air Shower Array (AGASA) observation. In this paper, we discuss the statistical significance of this discrepancy between the two experiments. We calculate arrival distribution of UHECRs above $10^{19}$ eV predicted by the source models constructed using the Optical Redshift Survey galaxy sample. We apply the new method developed by us for calculating arrival distribution in the presence of the galactic magnetic field. The great advantage of this method is that it enables us to calculate UHECR arrival distribution with lower energy ($\\sim 10^{19}$ eV) than previous studies within reasonable time by following only the trajectories of UHECRs actually reaching the earth. It has been realized that the small scale anisotropy observed by the AGASA can be explained with the source number density ...

  9. Ultra-High-Energy Cosmic Ray Acceleration by Magnetic Reconnection in Newborn Accretion Induced Collapse Pulsars

    CERN Document Server

    De Gouveia dal Pino, E M

    2000-01-01

    We here investigate the possibility that the ultra-high energy cosmic ray(UHECR) events observed above the GZK limit are mostly protons accelerated inreconnection sites just above the magnetosphere of newborn millisecond pulsarswhich are originated by accretion induced collapse (AIC). We find thatAIC-pulsars with surface magnetic fields $10^{12} G < B_{\\star} \\lesssim10^{15}$ G and spin periods $1 ms \\lesssim P_{\\star} < 60 ms$, are able toaccelerate particles to energies $\\geq 10^{20}$ eV. Because the expected rateof AIC sources in our Galaxy is very small (\\sim 10^{-5} yr^{-1}), thecorresponding contribution to the flux of UHECRs is neglegible, and the totalflux is given by the integrated contribution from AIC sources produced by thedistribution of galaxies located within the distance which is unaffected by theGZK cutoff ($\\sim 50 $ Mpc). We find that the reconnection efficiency factorneeds to be only $ \\xi \\gtrsim 3.6 \\times 10^{-3}$ in order to reproduce theobserved flux of UHECRs.

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

    CERN Document Server

    Bray, J D; 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. A method to provide a vast increase in collecting area is to use the lunar technique, in which ground-based radio telescopes search for the nanosecond radio flashes produced when a cosmic ray interacts with the Moon's surface. The technique is also sensitive to the associated flux of UHE neutrinos, which are expected from cosmic ray interactions during production and propagation, and the detection of which can also be used to identify the UHE cosmic ray source(s). An additional flux of UHE neutrinos may also be produced in the decays of topological defects from the early Universe. Observations with existing radio telescopes have shown that this technique is technically feasible, and established the required proced...

  11. Ultra-high energy physics and standard basic principles. Do Planck units really make sense?

    Science.gov (United States)

    Gonzalez-Mestres, Luis

    2014-04-01

    It has not yet been elucidated whether the observed flux suppression for ultra-high energy cosmic rays (UHECR) at energies above ≃ 4 x 1019 eV is a signature of the Greisen-Zatsepin-Kuzmin (GZK) cutoff or a consequence of other phenomena. In both cases, violations of the standard fundamental principles of Physics can be present and play a significant role. They can in particular modify cosmic-ray interactions, propagation or acceleration at very high energy. Thus, in a long-term program, UHECR data can hopefully be used to test relativity, quantum mechanics, energy and momentum conservation, vacuum properties... as well as the elementariness of standard particles. Data on cosmic rays at energies ≃ 1020 eV may also be sensitive to new physics generated well beyond Planck scale. A typical example is provided by the search for possible signatures of a Lorentz symmetry violation (LSV) associated to a privileged local reference frame (the "vacuum rest frame", VRF). If a VRF exists, the internal structure of standard particles at ultra-high energy can undergo substantial modifications. Similarly, the conventional particle symmetries may cease to be valid at such energies instead of heading to a grand unification and the structure of vacuum may no longer be governed by standard quantum field theory. Then, the question whether the notion of Planck scale still makes sense clearly becomes relevant and the very grounds of Cosmology can undergo essential modifications. UHECR studies naturally interact with the interpretation of WMAP and Planck observations. Recent Planck data analyses tend to confirm the possible existence of a privileged space direction. If the observed phenomenon turns out to be a signature of the spinorial space-time (SST) we suggested in 1996-97, then conventional Particle Physics may correspond to the local properties of standard matter at low enough energy and large enough distances. This would clearly strengthen the cosmological relevance of UHECR

  12. Clustering, Anisotropy, Spectra of Ultra High Energy Cosmic Ray: Finger-prints of Relic Neutrinos Masses in Dark Halos

    OpenAIRE

    Fargion, Daniele; Grossi, Marco; Lucentini, P. G. De Sanctis; Di Troia, C

    2001-01-01

    The Ultra High Energy Cosmic Ray UHECR, by UHE neutrino-relic neutrino Z showering in Hot Dark Halos HDM, should exhibits an energy spectra and an anisotropy reflecting (also) the relic neutrino masses and their hierarchical HDM halo clustering. A twin light neutrino mass splitting may reflect to twin Z resonance and into a complex UHECR spectra modulation, a twin bump, at the edge at highest GZK energy cut-off. Each possible neutrino mass associates a characteristic dark halo size (galactic,...

  13. Ultra-High Energy Cosmic Ray Probes of Large Scale Structure and Magnetic Fields

    CERN Document Server

    Sigl, G; Ensslin, T A; Sigl, Guenter; Miniati, Francesco; Ensslin, Torsten

    2004-01-01

    We study signatures of a structured universe in the multi-pole moments, auto-correlation function, and cluster statistics of ultra-high energy cosmic rays above $10**19 eV. We compare scenarios where the sources are distributed homogeneously or according to the baryon density distribution obtained from a cosmological large scale structure simulation. The influence of extragalactic magnetic fields is studied by comparing the case of negligible fields with fields expected to be produced along large scale shocks with a maximal strength consistent with observations. We confirm that strongly magnetized observers would predict considerable anisotropy on large scales, which is already in conflict with current data. In the best fit scenario only the sources are strongly magnetized, although deflection can still be considerable, of order 20 degrees up to 10**20 eV, and a pronounced GZK cutoff is predicted. We then discuss signatures for future large scale full-sky detectors such as the Pierre Auger and EUSO projects. ...

  14. Ultra-high-energy-cosmic-ray hot spots from tidal disruption events

    CERN Document Server

    Pfeffer, Daniel N; Kamionkowski, Marc

    2015-01-01

    We consider the possibility that tidal disruption events (TDEs) caused by supermassive black holes (SMBHs) in nearby galaxies can account for the ultra-high-energy cosmic-ray (UHECR) hot spot reported recently by the Telescope Array (TA) and the warm spot by Pierre Auger Observatory (PAO). We describe the expected cosmic-ray signal from a TDE and derive the constraints set by the timescale for dispersion due to intergalactic magnetic fields and the accretion time of the SMBH. We demonstrate that TDEs in M82 can explain the hot spot detected by the TA. Based on data-driven assumptions regarding the SMBH mass function, the luminosity scaling of the TDEs and the mass dependence of their rate, we then analyze the full parameter space of the model to search for consistency with the full-sky isotropic signal. Doing so, we show that TDEs can account for both the TA hot spot and full-sky UHECR observations. Using our model we show that the warm spot in the PAO data in the direction of Centaurus A (Cen A) can also be ...

  15. 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 ...

  16. Ultra-High Energy Cosmic Rays in a Structured and Magnetized Universe

    CERN Document Server

    Sigl, G; Ensslin, T A; Sigl, Guenter; Miniati, Francesco; Ensslin, Torsten

    2003-01-01

    The interpretation of observed sky distributions of ultra high energy cosmic rays may be affected non-trivially by considerable deflection by cosmic magnetic fields in the local large scale structure of the universe. We simulate propagation of cosmic ray nucleons above 10^{19} eV in scenarios where both the source distribution and magnetic fields within about 50 Mpc from us are obtained from an unconstrained large scale structure simulation. We find that consistency of predicted sky distributions with current data above 4 x 10^{19} eV favors magnetic fields of ~0.1 microGauss in our immediate environment, and a nearby source density of ~10^{-4}-10^{-3} Mpc^{-3}. At ~10^{19} eV an additional isotropic, presumably cosmological flux component should dominate the local component by about a factor three to be consistent with isotropy. We also discuss how future large scale full-sky detectors such as the Pierre Auger project will allow to put much more stringent constraints on source and magnetic field distribution...

  17. Large doppler shift in radar detection of ultra-high energy cosmic rays.

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, D. G.; High Energy Physics

    2008-01-01

    Radar detection of cosmic ray air showers has been discussed for 60 years, but never clearly observed. The topic was reexamined by Gorham in 2001 and some serious simulations were done by Takai, who also initiated the Mariachi project utilizing commercial television transmissions as a signal source. The air showers from ultra-high energy cosmic rays are expected to generate a plasma with plasma frequency in the high VHF region. One factor limiting the received signal strength is the short ion recombination time in air at low altitude. However, a major factor which has not been the center of attention so far is the possible large Doppler shifts for non-specular reflection, and the soft transition between specular and diffuse for small objects and short time scales. We discuss recent work on receivers, and simulations of the Doppler shift. These simulations assume a very short ion recombination time in the lower atmosphere, and use an extremely simple mathematical model. A central feature of our simulations is large Doppler shift from non-moving material.

  18. Full sky harmonic analysis hints at large ultra-high energy cosmic ray deflections

    International Nuclear Information System (INIS)

    The full-sky multipole coefficients of the ultra-high energy cosmic ray (UHECR) flux have been measured for the first time by the Pierre Auger and Telescope Array collaborations using a joint data set with E > 10 EeV. We calculate these harmonic coefficients in the model where UHECR are protons and sources trace the local matter distribution, and compare our results with observations. We find that the expected power for low multipoles (dipole and quadrupole, in particular) is sytematically higher than in the data: the observed flux is too isotropic. We then investigate to which degree our predictions are influenced by UHECR deflections in the regular Galactic magnetic field. It turns out that the UHECR power spectrum coefficients Cl are quite insensitive to the effects of the Galactic magnetic field, so it is unlikely that the discordance can be reconciled by tuning the Galactic magnetic field model. On the contrary, a sizeable fraction of uniformly distributed flux (representing for instance an admixture of heavy nuclei with considerably larger deflections) can bring simulations and observations to an accord

  19. Simulation of Ultra-High Energy Photon Propagation in the Geomagnetic Field

    CERN Document Server

    Homola, P; Heck, D; Klages, H; Pekala, J; Risse, M; Wilczynska, B; Wilczynski, H

    2003-01-01

    The identification of primary photons or specifying stringent limits on the photon flux is of major importance for understanding the origin of ultra-high energy (UHE) cosmic rays. We present a new Monte Carlo program allowing detailed studies of conversion and cascading of UHE photons in the geomagnetic field. The program named PRESHOWER can be used both as an independent tool or together with a shower simulation code. With the stand-alone version of the code it is possible to investigate various properties of the particle cascade induced by UHE photons interacting in the Earth's magnetic field before entering the Earth's atmosphere. Combining this program with an extensive air shower simulation code such as CORSIKA offers the possibility of investigating signatures of photon-initiated showers. In particular, features can be studied that help to discern such showers from the ones induced by hadrons. As an illustration, calculations for the conditions of the southern part of the Pierre Auger Observatory are pr...

  20. 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...

  1. The isotropy problem of sub-ankle ultra high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rahul; Eichler, David [Physics Department, Ben-Gurion University, Be' er-Sheba 84105 (Israel)

    2014-01-20

    We study the time dependent propagation of sub-ankle ultra high energy cosmic rays (UHECRs) originating from point-like Galactic sources. We show that drift in the Galactic magnetic field (GMF) may play an important role in the propagation of UHECRs and their measured anisotropy, particularly when the transport is anisotropic. To fully account for the discreteness of UHECR sources in space and time, a Monte Carlo method is used to randomly place sources in the Galaxy. The low anisotropy measured by Auger is not generally characteristic of the theoretical models, given that the sources are distributed in proportion to the star formation rate, but it can possibly be understood as (1) intermittency effects due to the discrete nature of the sources or, with extreme parameters, (2) a cancellation of drift current along a current sheet with outward radial diffusive flux. We conclude that it is possible to interpret the Galactic sub-ankle CR flux as being due entirely to intermittent discrete Galactic sources distributed in proportion to star formation, but only with a probability of roughly 35%, of which the spectrum is in accord with observations about 30% of the time. An alternative explanation for the low anisotropy may be that they are mostly extragalactic and/or heavy.

  2. 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.

  3. Propagation of ultra-high-energy cosmic rays and their secondaries with CRPropa

    International Nuclear Information System (INIS)

    Due to experiments like the Pierre Auger Observatory (Auger) and the Telescope Array (TA), high-statistics data is becoming available on the energy spectrum, the composition and the arrival directions of ultra-high-energy cosmic rays (UHECRs, cosmic rays with energies above ∝ 1017 eV). To interpret this data in terms of actual astrophysical parameters, or to test astrophysical models against the measured data, dedicated simulations of the propagation of UHECRs from their sources to Earth are needed. To this end, the UHECR propagation code called CRPropa has been developed. It can take into account all relevant interactions with ambient photon backgrounds (pair production, photodisintegration and photopion production) as well as nuclear decay, cosmological evolution effects and deflections in extragalactic and galactic magnetic fields. CRPropa, including its newest features, is described in this thesis. When considering the propagation of ultra-high-energy nuclei, the dominant interaction for most isotopes and energies is photodisintegration. Photodisintegration has been implemented in CRPropa for all relevant isotopes (up to iron) and all relevant photodisintegration channels using cross-section calculations with the publicly-available code called TALYS, including extensions for the low mass numbers. This photodisintegration setup is compared here extensively with the photodisintegration scheme developed by Puget, Stecker and Bredekamp, leading to several improvements on the cross sections implemented in CRPropa. In the interactions of UHECRs with background photon fields, secondary neutrinos and photons, so-called cosmogenic neutrinos and photons, can be created. CRPropa can simulate the production and propagation of these secondary particles as well. The IceCube Neutrino Observatory (IceCube) has recently reported the first observation of extraterrestrial neutrinos in the PeV energy range. In this work is investigated whether these neutrinos could have

  4. Simulation of ultra-high energy photon propagation with PRESHOWER 2.0

    Science.gov (United States)

    Homola, P.; Engel, R.; Pysz, A.; Wilczyński, H.

    2013-05-01

    In this paper we describe a new release of the PRESHOWER program, a tool for Monte Carlo simulation of propagation of ultra-high energy photons in the magnetic field of the Earth. The PRESHOWER program is designed to calculate magnetic pair production and bremsstrahlung and should be used together with other programs to simulate extensive air showers induced by photons. The main new features of the PRESHOWER code include a much faster algorithm applied in the procedures of simulating the processes of gamma conversion and bremsstrahlung, update of the geomagnetic field model, and a minor correction. The new simulation procedure increases the flexibility of the code so that it can also be applied to other magnetic field configurations such as, for example, encountered in the vicinity of the sun or neutron stars. Program summaryProgram title: PRESHOWER 2.0 Catalog identifier: ADWG_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWG_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3968 No. of bytes in distributed program, including test data, etc.: 37198 Distribution format: tar.gz Programming language: C, FORTRAN 77. Computer: Intel-Pentium based PC. Operating system: Linux or Unix. RAM:package, IGRF [1, 2], DBSKA [3], ran2 [4] Running time: 100 preshower events with primary energy 1020 eV require a 2.66 GHz CPU time of about 200 sec.; at the energy of 1021 eV, 600 sec.

  5. Propagation and sky distribution of ultra-high energy cosmic rays

    International Nuclear Information System (INIS)

    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)

  6. On Ultra-high-energy Cosmic Rays and Their Resultant Gamma-Rays

    Science.gov (United States)

    Gavish, Eyal; Eichler, David

    2016-05-01

    The Fermi Large Area Telescope collaboration has recently reported on 50 months of measurements of the isotropic extragalactic gamma-ray background (EGRB) spectrum between 100 MeV and 820 GeV. Ultra-high-energy cosmic ray (UHECR) protons interact with the cosmic microwave background photons and produce cascade photons of energies 10 MeV–1 TeV that contribute to the EGRB flux. We examine seven possible evolution models for UHECRs and find that UHECR sources that evolve as the star formation rate (SFR), medium low luminosity active galactic nuclei type-1 (L = 1043.5 erg s‑1 in the [0.5–2] KeV band), and BL Lacertae objects (BL Lacs) are the most acceptable given the constraints imposed by the observed EGRB. Other possibilities produce too much secondary γ-radiation. In all cases, the decaying dark matter (DM) contribution improves the fit at high energy, but the contribution of still unresolved blazars, which would leave the smallest role for decaying DM, may yet provide an alternative improvement. The possibility that the entire EGRB can be fitted with resolvable but not-yet-resolved blazars, as recently claimed by Ajello et al., would leave little room in the EGRB to accommodate γ-rays from extragalactic UHECR production, even for many source evolution rates that would otherwise be acceptable. We find that under the assumption of UHECRs being mostly protons, there is not enough room for producing extragalactic UHECRs with active galactic nucleus, gamma-ray burst, or even SFR source evolution. Sources that evolve as BL Lacs, on the other hand, would produce much less secondary γ-radiation and would remain a viable source of UHECRs, provided that they dominate.

  7. 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...

  8. A new limit on the Ultra-High-Energy Cosmic-Ray flux with the Westerbork Synthesis Radio Telescope

    CERN Document Server

    ter Veen, S; Falcke, H; James, C W; Mevius, M; Scholten, O; Singh, K; Stappers, B; de Vries, K D

    2010-01-01

    A particle cascade (shower) in a dielectric, for example as initiated by an ultra-high energy cosmic ray, will have an excess of electrons which will emit coherent \\v{C}erenkov radiation, known as the Askaryan effect. In this work we study the case in which such a particle shower occurs in a medium just below its surface. We show, for the first time, that the radiation transmitted through the surface is independent of the depth of the shower below the surface when observed from far away, apart from trivial absorption effects. As a direct application we use the recent results of the NuMoon project, where a limit on the neutrino flux for energies above $10^{22}$\\,eV was set using the Westerbork Synthesis Radio Telescope by measuring pulsed radio emission from the Moon, to set a limit on the flux of ultra-high-energy cosmic rays.

  9. Present status and future prospect of the ultra-high intensity physics experiments and high-energy ion generation

    International Nuclear Information System (INIS)

    Recently, ultra-high intensity short pulse lasers have been applied to the fields of hard x-ray generation and high energy particle generation [1, 2]. The essence of the laser-produced plasma is that a laser can feed its ultra-high energy density into the matter via the ponderomotive heating of electrons. Then the electron energy is transferred into the atoms and ions, which include excitation, ionization by collisions. The electron energy is also converted into the energy of energetic ions by electro-static potential driven by charge separation field which is caused by electron ejection from a plasma. Subsequently, high flux few tens of MeV x-ray can drive nuclear reactions, which open up the new fields of plasma physics and applications. The ultra-high intensity short pulse lasers will also contribute to the cancer therapy as a source of energetic particles. We are now characterizing laser-driven ion source [3] in collaboration with several domestic Institutes and Universities. The basic laser-plasma interaction study with a practical point of view opens up the new attractive fields not only the practical applications but also the new aspects of the basic sciences such as control of a high temperature and high-density relativistic plasma. The high intensity physics experiments of this project are schematically shown in Fig. 1. (author)

  10. Future use of silicon photomultipliers for the fluorescence detection of ultra-high-energy cosmic rays

    Science.gov (United States)

    Stephan, Maurice; Hebbeker, Thomas; Lauscher, Markus; Meurer, Christine; Niggemann, Tim; Schumacher, Johannes

    2011-10-01

    A sophisticated technique to measure extensive air showers initiated by ultra-high-energy cosmic rays is by means of fluorescence telescopes. Secondary particles of the air shower excite nitrogen molecules of the atmosphere, which emit fluorescence light when they de-excite. Due to their high photon detection efficiency (PDE) silicon photomultipliers (SiPMs) promise to increase the sensitivity of todays fluorescence telescopes which use photomultiplier tubes - for example the fluorescence detector of the Pierre Auger Observatory. On the other hand drawbacks like a small sensitive area, a strong temperature dependency and a high noise rate have to be managed. We present plans for a prototype fluorescence telescope using SiPMs and a special light collecting optical system of Winston cones to increase the sensitive area. In this context we made measurements of the relative PDE of SiPMs depending on the incident angle of light. The results agree with calculations based on the Fresnel equations. Furthermore, measurements of the brightness of the night sky are presented since this photon flux is the main background to the fluorescence signals of the extensive air showers. To compensate the temperature dependency of the SiPM, frontend electronics make use of temperature sensors and microcontrollers to directly adjust the bias-voltage according to the thermal conditions. To reduce the noise rate we study the coincidence of several SiPMs signals triggered by cosmic ray events. By summing up these signals the SiPMs will constitute a single pixel of the fluorescence telescope.

  11. INTERGALACTIC MAGNETIC FIELD AND ARRIVAL DIRECTION OF ULTRA-HIGH-ENERGY PROTONS

    International Nuclear Information System (INIS)

    We studied how the intergalactic magnetic field (IGMF) affects the propagation of super-Greisen-Zatsepin-Kuz'min (GZK) protons that originate from extragalactic sources within the local GZK sphere. To this end, we set up hypothetical sources of ultra-high-energy cosmic rays (UHECRs), virtual observers, and the magnetized cosmic web in a model universe constructed from cosmological structure formation simulations. We then arranged a set of reference objects mimicking active galactic nuclei (AGNs) in the local universe, with which correlations of simulated UHECR events are analyzed. With our model IGMF, the deflection angle between the arrival direction of super-GZK protons and the sky position of their actual sources is quite large with a mean value of (θ) ∼ 15 deg. and a median value of Θ-tilde∼7 deg. - 10 deg. On the other hand, the separation angle between the arrival direction and the sky position of nearest reference objects is substantially smaller with (S) ∼ 3.05-40, which is similar to the mean angular distance in the sky to nearest neighbors among the reference objects. This is a direct consequence of our model that the sources, observers, reference objects, and the IGMF all trace the matter distribution of the universe. The result implies that extragalactic objects lying closest to the arrival direction of UHECRs are not necessarily their actual sources. With our model for the distribution of reference objects, the fraction of super-GZK proton events, whose closest AGNs are true sources, is less than 1/3. We discussed implications of our findings for correlation studies of real UHECR events.

  12. Bounds on Direct Couplings of Superheavy Metastable Particles to the Inflaton Field from Ultra High Energy Cosmic Ray Events

    CERN Document Server

    Campos, A H; Reis, H C; Rosenfeld, R; Sato, R

    2001-01-01

    Top-down models for the origin of ultra high energy cosmic rays (UHECR's) propose that these events are the decay products of relic superheavy metastable particles, usually called $X$ particles. These particles can be produced in the reheating period following the inflationary epoch of the early Universe. We obtain constraints on some parameters such as the lifetime and direct couplings of the $X$-particle to the inflaton field from the requirement that they are responsible for the observed UHECR flux.

  13. Observational Constraints on the Ultra-high Energy Cosmic Neutrino Flux from the Second Flight of the ANITA Experiment

    OpenAIRE

    The ANITA Collaboration; Gorham, P. W.; Allison, P.; Baughman, B. M.; Beatty, J. J.; Belov, K.; Besson, D. Z.; Bevan, S; Binns, W. R.; Chen, C.; Chen, P; Clem, J. M.; Connolly, A.; Detrixhe, M.; De Marco, D.

    2010-01-01

    The Antarctic Impulsive Transient Antenna (ANITA) completed its second long-duration balloon flight in January 2009, with 31 days aloft (28.5 live days) over Antarctica. ANITA searches for impulsive coherent radio Cherenkov emission from 200 to 1200 MHz, arising from the Askaryan charge excess in ultra-high energy neutrino-induced cascades within Antarctic ice. This flight included significant improvements over the first flight in the payload sensitivity, efficiency, and a flight trajectory o...

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

    OpenAIRE

    Karg, Timo

    2006-01-01

    This thesis investigates a new approach towards 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 acoustic pulses from 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 detectio...

  15. Ultra-high Energy Neutrinos from Gamma-Ray Burst Afterglows Using the Swift-UVOT Data

    Science.gov (United States)

    Nir, Guy; Guetta, Dafne; Landsman, Hagar; Behar, Ehud

    2016-02-01

    We consider a sample of 107 gamma-ray bursts (GRBs) for which early ultra-violet emission was measured by Swift and extrapolate the photon intensity to lower energies. Protons accelerated in the GRB jet may interact with such photons to produce charged pions and subsequently ultra high energy neutrinos {\\varepsilon }ν ≥slant {10}16 eV. We use simple energy conversion efficiency arguments to predict the maximal neutrino flux expected from each GRB. We estimate the neutrino detection rate at large area radio based neutrino detectors and conclude that the early afterglow neutrino emission is too weak to be detected even by next generation neutrino observatories.

  16. Examination of a proposed technique for the economical detection and analysis of ultra-high energy cosmic ray showers

    International Nuclear Information System (INIS)

    A version of a ultra-high energy cosmic ray detection and analysis technique suggested by Linsley has been found to be both feasible and economical. Linsley proposed a coventional arrangement consisting of four scintillators each of area 1 m2 placed at the corners of a 30 m square. It was suggested that by measuring the spread in arrival times of shower particles within each detector, one should be able to estimate the lateral distance to the core of the triggering shower. It is possible to avoid poor particle statistics if a detector specifically sensitive to low energy gamma rays is used

  17. Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory

    Czech Academy of Sciences Publication Activity Database

    Abreu, P.; Aglietta, M.; Ahlers, M.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Mandát, Dušan; Nečesal, Petr; Nožka, Libor; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovancová, Jaroslava; Schovánek, Petr; Tománková, L.; Trávníček, Petr; Vícha, Jakub

    2013-01-01

    Roč. 2013, č. 5 (2013), s. 1-20. ISSN 1475-7516 R&D Projects: GA MŠk LA08015; GA TA ČR TA01010517; GA MŠk(CZ) MEB111003; GA AV ČR KJB100100904; GA MŠk(CZ) LA08016 Institutional research plan: CEZ:AV0Z10100502; CEZ:AV0Z10100522 Keywords : ultra high energy cosmic rays * cosmic ray experiments Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.877, year: 2013 http://iopscience.iop.org/1475-7516/2013/05/009/pdf/1475-7516_2013_05_009.pdf

  18. Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory

    OpenAIRE

    PIERRE AUGER Collaboration; Abreu, P; Pastor, Sergio

    2013-01-01

    We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack of significant clustering in the arrival directions of the highest energy events detected at the Pierre Auger Observatory. The density of uniformly distributed sources of equal intrinsic intensity was found to be larger than similar to (0.06 – 5) x 10(-4) Mpc(-3) at 95% CL, depending on the magnitude of the magnetic defections. Similar bounds, in the range (0.2 – 7) x 10(-4) Mpc(-3), were obtained ...

  19. 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.

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

    International Nuclear Information System (INIS)

    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

  1. 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...

  2. 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.

  3. Energy and flux measurements of ultra-high energy cosmic rays observed during the first ANITA flight

    Science.gov (United States)

    Schoorlemmer, H.; Belov, K.; 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., Jr.; 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.; Huege, T.; Heber, C. L.; Hoover, S.; Israel, M. H.; Javaid, A.; Kowalski, J.; Lam, J.; Learned, J. G.; 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.

    2016-04-01

    The first flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment recorded 16 radio signals that were emitted by cosmic-ray induced air showers. The dominant contribution to the radiation comes from the deflection of positrons and electrons in the geomagnetic field, which is beamed in the direction of motion of the air shower. For 14 of these events, this radiation is reflected from the ice and subsequently detected by the ANITA experiment at a flight altitude of ∼36 km. 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 × 1018 eV, which is significantly lower than the previous estimate. 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 and find agreement with measurements performed at other observatories. In addition, we find that the ANITA data set is consistent with Monte Carlo simulations for the total number of observed events and with the properties of those events.

  4. 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.

  5. 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...

  6. On the burst activity of the Crab Nebula and pulsar at high and ultra-high energies

    International Nuclear Information System (INIS)

    Recent experiments with satellite gamma-ray telescopes Fermi-LAT and AGILE in which bursts of gamma-rays from the Crab Nebula were detected in the energy range around 100 MeV have aroused keen interest, if not sensation. However, as long ago as more than 20 years from now the data on a possible burst in the Crab Nebula at much higher energies, about 100 TeV, were published. Characteristics of transient and stationary fluxes of gamma rays from the Crab Nebula in various energy ranges are discussed in this paper, and it is shown that the old data obtained at ultra-high energy can be reasonably consistent with the modern pattern of burst activity of the source.

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

    International Nuclear Information System (INIS)

    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 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 ∼ 35 keV/nucleon from the interactions of 400 MeV/nucleon 16O with nat Xe gas targets

  8. 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.

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

    International Nuclear Information System (INIS)

    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.)

  10. The optical depth of the Universe for ultra-high energy cosmic ray scattering in the magnetized large scale structure

    CERN Document Server

    Kotera, Kumiko

    2008-01-01

    This paper provides an analytical description of the transport of ultra-high energy cosmic rays in an inhomogeneously magnetized intergalactic medium. This latter is modeled as a collection of magnetized scattering centers such as radio cocoons, magnetized galactic winds, clusters or magnetized filaments of large scale structure, with negligible magnetic fields in between. Magnetic deflection is no longer a continuous process, it is rather dominated by scattering events. We study the interaction between high energy cosmic rays and the scattering agents. We then compute the optical depth of the Universe to cosmic ray scattering and discuss the phenomological consequences for various source scenarios. For typical parameters of the scattering centers, the optical depth is greater than unity at 5.10^{19}eV, but the total angular deflection is smaller than unity. One important consequence of this scenario is the possibility that the last scattering center encountered by a cosmic ray be mistaken with the source of ...

  11. Global anisotropy of arrival directions of ultra-high-energy cosmic rays: capabilities of space-based detectors

    International Nuclear Information System (INIS)

    Planned space-based ultra-high-energy cosmic-ray detectors (TUS, JEM-EUSO and S-EUSO) are best suited for searches of global anisotropies in the distribution of arrival directions of cosmic-ray particles because they will be able to observe the full sky with a single instrument. We calculate quantitatively the strength of anisotropies associated with two models of the origin of the highest-energy particles: the extragalactic model (sources follow the distribution of galaxies in the Universe) and the superheavy dark matter model (sources follow the distribution of dark matter in the Galactic halo). Based on the expected exposure of the experiments, we estimate the optimal strategy for efficient search of these effects

  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. Observational Constraints on the Ultra-high Energy Cosmic Neutrino Flux from the Second Flight of the ANITA Experiment

    CERN Document Server

    Gorham, P W; Baughman, B M; Beatty, J J; Belov, K; Besson, D Z; Bevan, S; Binn, W R; Chen, C; Chen, P; Clem, J M; Connolly, A; Detrixhe, M; DeMarco, D; Dowkontt, P F; DuVernois, M; Grashorn, E W; Hill, B; Hoover, S; Huang, M; Israel, M H; Javaid, A; Liewer, K M; Matsuno, S; Mercurio, B C; Miki, C; Mottram, M; Nam, J; Nichol, R J; Palladino, K; Romero-Wolf, A; Ruckman, L; Saltzberg, D; Seckel, D; Varner, G S; Vieregg, A G; Wang, Y

    2010-01-01

    The Antarctic Impulsive Transient Antenna (ANITA) completed its second long-duration balloon flight in January 2009, with 31 days aloft over Antarctica. ANITA searches for impulsive coherent radio Cherenkov emission from 200 to 1200 MHz, arising from the Askaryan charge excess in ultra-high energy neutrino-induced cascades within Antarctic ice. This flight included significant improvements over the first flight in the payload sensitivity, efficiency, and a flight trajectory over deeper ice. Analysis of in-flight calibration pulses from surface and sub-surface locations verifies the expected sensitivity. In a blind analysis, we find 2 surviving events on a background, mostly anthropogenic, of 0.97+-0.39 events. We set the strongest limit to date for 1-1000 EeV cosmic neutrinos, excluding several current cosmogenic neutrino models.

  14. Ultra-high energy cosmic rays: analysis of extensive air showers and their associated electromagnetic signal in the MHz domain

    International Nuclear Information System (INIS)

    In this HDR (accreditation to supervise research) report, the author proposes a review of the present results in the field of ultra-high energy cosmic rays. After a presentation of some results about the Fermi mechanism to accelerate cosmic rays, the author more particularly addresses the reconstruction of air showers, and the search for sources. He also addresses the radio signal emitted by air shower secondary positrons and electrons. He proposes an overview of the present knowledge on the basis of present experiments. Data show that the electric field is mainly due to the influence of the Earth magnetic field which acts on electrons and positrons, but more recently, the contribution due to electrons in excess seems to appear in data. The author reports the last advances in the field of simulation of the electric field, with notably the prediction of new signal produced by the disappearance of the air shower during its absorption by the soil

  15. The JEM-EUSO mission: a space observatory to study the origin of Ultra-High Energy Cosmic Rays

    Science.gov (United States)

    Bertaina, M.; Parizot, E.

    2014-11-01

    The Extreme Universe Space Observatory (EUSO) onboard the Japanese Experiment Module (JEM-EUSO) of the International Space Station (ISS) is an innovative space-based mission with the aim of detecting Ultra-High Energy Cosmic Rays (UHECRs) from the ISS, by using the Earth's atmosphere as a calorimeter viewed by a fluorescence telescope. An observatory able to produce an arrival direction map with more than several hundreds events above 5 × 1019 eV would give important information on the origin of the UHECRs and identify structures in the sky map that contain information about the source density and/or distribution. This is likely to lead to an understanding of the acceleration mechanisms with a high potential for producing discoveries in astrophysics and/or fundamental physics. The scientific motivations of the mission as well as the current development status of the instrument and its performance are reviewed.

  16. The JEM-EUSO mission: a space observatory to study the origin of Ultra-High Energy Cosmic Rays

    International Nuclear Information System (INIS)

    The Extreme Universe Space Observatory (EUSO) onboard the Japanese Experiment Module (JEM-EUSO) of the International Space Station (ISS) is an innovative space-based mission with the aim of detecting Ultra-High Energy Cosmic Rays (UHECRs) from the ISS, by using the Earth's atmosphere as a calorimeter viewed by a fluorescence telescope. An observatory able to produce an arrival direction map with more than several hundreds events above 5 × 1019 eV would give important information on the origin of the UHECRs and identify structures in the sky map that contain information about the source density and/or distribution. This is likely to lead to an understanding of the acceleration mechanisms with a high potential for producing discoveries in astrophysics and/or fundamental physics. The scientific motivations of the mission as well as the current development status of the instrument and its performance are reviewed

  17. Small-x parton densities from HERA and the ultra-high energy neutrino-nucleon cross sections

    International Nuclear Information System (INIS)

    In light of recent measurements of the nucleon structure function in the small-x deep-inelastic regime at HERA and the consequently improved theoretical understanding of the quark distributions in this range of parton fractional momentum, new results for the neutrino-nucleon cross section at ultra high energies are presented up to Eν ∼ 1021 eV. The results are relevant to deep underground muon detectors looking for such neutrinos. For ∼ 1020 eV neutrinos, our cross sections are about a factor of 4 to 10 times larger than the previously reported results by Reno, Quigg and Walker. Implications of this new neutrino-nucleon cross section for a variety of current and future neutrino detectors are also discussed. (author)

  18. 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.

  19. Study of dispersion of mass distribution of ultra-high energy cosmic rays using a surface array of muon and electromagnetic detectors

    Czech Academy of Sciences Publication Activity Database

    Vícha, Jakub; Trávníček, Petr; Nosek, D.; Ebr, Jan

    2015-01-01

    Roč. 67, Sep (2015), 11-17. ISSN 0927-6505 R&D Projects: GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : ultra-high energy cosmic rays * extensive air showers * surface detectors * CIC method * mass composition Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.584, year: 2014

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

    International Nuclear Information System (INIS)

    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.)

  1. 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.)

  2. Ultra High-Energy Cosmic Ray Production by Turbulence in Gamma-Ray Burst Jets and Cosmogenic Neutrinos

    CERN Document Server

    Asano, Katsuaki

    2016-01-01

    We propose a novel model to produce ultra-high-energy cosmic-rays (UHECRs) in gamma-ray burst (GRB) jets. After the prompt gamma-ray emission, hydrodynamical turbulence is excited in the GRB jets at or before the afterglow phase. The mildly relativistic turbulence stochastically accelerates protons. The acceleration rate is much slower than the usual first-order shock acceleration rate, but in this case it can be energy-independent. The resultant UHECR spectrum is so hard that the bulk energy is concentrated in the highest energy range, resulting in a moderate requirement for the typical cosmic ray luminosity of $\\sim 10^{53.5}~\\mbox{erg}~\\mbox{s}^{-1}$. In this model, the secondary gamma-ray and neutrino emissions initiated by photopion production are significantly suppressed. Although the UHECR spectrum at injection shows a curved feature, this does not conflict with the observed UHECR spectral shape. The cosmogenic neutrino spectrum in the $10^{17}$--$10^{18}$ eV range becomes distinctively hard in this mo...

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

    International Nuclear Information System (INIS)

    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 65o. 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.

  4. 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...

  5. 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.

  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. Clustering, Anisotropy, Spectra of Ultra High Energy Cosmic Ray Finger-prints of Relic Neutrinos Masses in Dark Halos

    CERN Document Server

    Fargion, D; De Sanctis-Lucentini, P G; Troia, C D; Fargion, Daniele; Grossi, Marco

    2001-01-01

    The Ultra High Energy Cosmic Ray UHECR, by UHE neutrino-relic neutrino Z showering in Hot Dark Halos HDM, should exhibits an energy spectra and an anisotropy reflecting (also) the relic neutrino masses and their hierarchical HDM halo clustering. A twin light neutrino mass splitting may reflect to twin Z resonance and into a complex UHECR spectra modulation, a twin bump, at the edge at highest GZK energy cut-off. Each possible neutrino mass associates a characteristic dark halo size (galactic, local, Super Cluster) and its local anisotropy due to our peculiar position within that dark matter distribution. A neutrino HDM halo around a Mpc will allow to the UHECR neutron secondary component at E_n> 10^{20} eV (due to Z decay) to arise playing a role comparable with the charged p- anti{p} ones. Their un-deflected n-anti{n} (or decayed p-anti{p}) flight is shorter leading to a prompt and hard UHECR trace pointing toward the original UHECR source direction. The direct p -anti{p} pairs are split and spread by random...

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

    International Nuclear Information System (INIS)

    We consider the behavior of the innermost stable circular orbit (ISCO) in the magnetic field near ''dirty'' (surrounded by matter) axially symmetric black holes. The cases of near-extremal, extremal, and nonextremal black holes are analyzed. For nonrotating black holes, in the strong magnetic field ISCO approaches the horizon (when backreaction of the field on the geometry is neglected). Rotation destroys this phenomenon. The angular momentum and radius of ISCO look model-independent in the main approximation. We also study the collisions between two particles that results in the ultra-high energy Ec.m. in the center-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 energy and angular momentum typical of ISCO. If the magnetic field is strong enough and a black hole is slowly rotating, Ec.m. can become arbitrarily large. The kinematics of the high-energy collision is discussed. As an example, we consider the magnetized Schwarzschild black hole for an arbitrary strength of the field (the Ernst solution). It is shown that backreaction of the magnetic field on the geometry can bound the growth of Ec.m. (orig.)

  9. Ultra-high frequency induction energy effects on refractory oxides as applied to processing and immobilization of radioactive waste

    Science.gov (United States)

    Roach, Jay A.

    The application of ultra-high frequency induction melting of refractory oxides (i.e. borosilicate glass [BSG]) has been extensively investigated to determine the feasibility of developing and implementing an innovative inductively heated draining technique that is reliable and predictable. The primary purpose is for immobilizing highly radioactive waste streams resulting from reprocessing of spent nuclear fuel. This work has included development and validation of a numerical model, using ANSYS MultiPhysics software, as well as numerous proof-of-concept and pilot-scale experimental tests. The model is a steady state axially-symmetric geometry for a cylindrical water-cooled crucible that includes two separate induction energy sources operating at different frequencies. It accounts for the induction energy interactions, thermal conduction, convection, and radiation effects, as well as hydrodynamic phenomenon due to buoyancy effects. The material property models incorporated into the numerical model include temperature dependence up to 2,000°C of key parameters including density, specific heat, thermal conductivity, and electrical conductivity, which can vary by several orders of magnitude within the temperature variations seen. The model has been experimentally validated, and shown to provide excellent representation of steady state temperature distributions, convection cell configurations, and flow field velocities for molten low conductivity materials. Thus, it provides the capability to conduct parametric studies to understand operational sensitivities and geometry effects that determine the performance of the inductively heated draining device, including scale-up effects. Complementary experimental work has also been conducted to test the model predictions, and iteratively used to improve the model accuracy. However, the primary focus of the experimental efforts was to demonstrate the feasibility of the inductively heated draining technique for application to

  10. Planet-sized Detectors for Ultra-high Energy Neutrinos & Cosmic Rays

    OpenAIRE

    Gorham, Peter W.

    2004-01-01

    Extragalactic astronomy with photons ends at ~0.1 PeV, but we know there are astrophysical sources for seven more decades of energy beyond this. To probe the highest energy sources and particles in the universe, new messengers, such as neutrinos, and detectors with planet-sized areas are required. This note provides a glimpse of the possibilities.

  11. Ultra-high energy physics and standard basic principles : Do Planck units really make sense ?

    OpenAIRE

    Gonzalez-Mestres, Luis

    2013-01-01

    International audience It has not yet been elucidated whether the observed flux suppression for ultrahigh energy cosmic rays (UHECR) at energies above 4 x 10E19 eV is a signature of the Greisen-Zatsepin-Kuzmin (GZK) cutoff or a consequence of other phenomena. In both cases, violations of the standard fundamental principles of Physics can be present and play a significant role. They can in particular modify cosmic-ray interactions, propagation or acceleration at very high energy. Thus, in a...

  12. 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...

  13. 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...

  14. The Ultra-High Energy Cosmic Ray Spectrum Measured by the Telescope Array's Middle Drum Detector

    OpenAIRE

    Rodriguez, Douglas; Collaboration, Matt Wood for the Telescope Array

    2011-01-01

    The Telescope Array's Middle Drum fluorescence detector was constructed using refurbished telescopes from the High Resolution Fly's Eye (HiRes) experiment. As such, there is a direct comparison between these two experiments' fluorescence energy spectra. An energy spectrum has been calculated based on one year of collected data by the Middle Drum site of Telescope Array and agrees well with the HiRes monocular spectra. The quality of the Middle Drum results has also been determined to show goo...

  15. 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...

  16. 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

    2015-11-01

    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 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.

  17. 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.

  18. 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.

  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. Method for calculating arrival distribution of ultra-high-energy cosmic rays with modifications by the galactic magnetic field

    International Nuclear Information System (INIS)

    We present a method for calculating arrival distribution of Ultra-High Energy Cosmic Rays (UHECRs) including modifications by the galactic magnetic field. We perform numerical simulations of UHE anti-protons, which are injected isotropically at the earth, in the Galaxy and record the directions of velocities at the earth and outside the Galaxy for all of the trajectories. We then select some of them so that the resultant mapping of the velocity directions outside the Galaxy of the selected trajectories corresponds to a given source location scenario, applying Liouville's theorem. Using this method for our source location scenario which is adopted in our recent study and can explain the AGASA observation above 4 x 1019 eV, we calculate the arrival distribution of UHECRs including lower energy (E > 1019 eV) ones. We find that our source model can reproduce the AGASA experiment. We also demonstrate the UHECR arrival distribution with the event number expected by future experiments in the next few years

  1. Patterns in ultra-high energy cosmic ray arrival directions: a possible footprint of large scale cosmic structures

    International Nuclear Information System (INIS)

    The public available data of cosmic ray arrival directions with energies above 4 x 1019 eV present a broad maximum in the cumulative two-point autocorrelation function around 25 degrees. This has been interpreted as the first imprint of the filamentary pattern of large scale structures (LSS) of matter in the near universe. We analyze this suggestion in light of the clustering properties expected from a catalogue of galaxies of the local universe (redshift z ∼< 0:06). The data reproduce particularly well the clustering properties of the nearby universe within z ∼< 0:02. There is no statistically significant cross-correlation between data and structures, although intriguingly the nominal cross-correlation chance probability for displacements within ∼50 degree drops from O(50%) to O(10%) using the catalogue with a smaller horizon. Our results suggest a relevant role of magnetic fields (possibly extragalactic ones, too) and/or possibly some heavy nuclei fraction in the ultra-high energy cosmic rays

  2. 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.)

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

    International Nuclear Information System (INIS)

    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 km3 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 1.5.10-8E-2 GeVs-1sr-1cm-2 is reached, which is valid for a diffuse electron neutrino flux proportional to E-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.)

  4. Superconducting ultra-high energy resolution Gamma spectrometers for nuclear safeguards applications

    International Nuclear Information System (INIS)

    Superconducting Gamma-ray spectrometers offer an order of magnitude improvement in energy resolution over conventional germanium or scintillator detectors, and can improve the precision of non-destructive isotope analysis accordingly. We are developing spectrometers based on bulk tin absorbers and molybdenum-copper multilayer sensors operated at the transition between their superconducting and normal state. They are cooled to their operating temperature of ∼0.1K in an adiabatic demagnetization refrigerator, and have achieved an energy resolution between 50 and 90 eV FWHM at 100 keV. We discuss the performance of the instruments in the context of nuclear safeguards applications. (author)

  5. Core, Mantle, Crust Imaging the Earth's Interior with Ultra-High Energy Neutrino Tomography

    CERN Document Server

    Ralston, J P; Jain, P L; Frichter, George M.; Jain, Pankaj; Ralston, John P.

    1999-01-01

    We report on the feasibility of using an isotropic flux of cosmic neutrinos in the energy range of 10 to 10,000 TeV to study the interior geophysical structure of the Earth. The angular distribution of events in a $\\sim {\\rm km}^3$-scale neutrino telescope can be inverted to yield the Earth's nucleon density distribution. The approach is independent of previous seismic methods. The energy spectrum of the neutrino primaries can also be determined from consistency with the angular distribution. Depending on neutrino flux, a reasonable density determination can be obtained with a few hundred receivers operating for a few years.

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

    International Nuclear Information System (INIS)

    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

  7. 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.

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

    Science.gov (United States)

    Böser, Sebastian

    2013-06-01

    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 in dense media

  9. 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

  10. Symmetric inertial confinement fusion implosions at ultra-high laser energies

    International Nuclear Information System (INIS)

    The first indirect-drive hohlraum experiments at the National Ignition Facility have demonstrated symmetric capsule implosions at unprecedented laser drive energies of 0.7 MJ. 192 simultaneously fired laser beams heat ignition hohlraums to radiation temperatures of 3.3 million Kelvin compressing 1.8-millimeter capsules by the soft x rays produced by the hohlraum. Self-generated plasma-optics gratings on either end of the hohlraum tune the laser power distribution in the hohlraum producing symmetric x-ray drive as inferred from capsule self-emission measurements. These experiments indicate conditions suitable for compressing deuterium-tritium filled capsules with the goal to achieve burning fusion plasmas and energy gain in the laboratory.

  11. Ultra high energy gamma rays and observations with CYGNUS/MILAGRO

    International Nuclear Information System (INIS)

    This talk discusses high-energy observations of the Crab pulsar/nebula and the pulsar in the X-ray binary, Hercules X-1, and makes the case for continued observations with ground-based γ-ray detectors. The CYGNUS Air Shower Array has a wide field of view on monitors several astrophysical γ-ray sources at the same time, many of which are prime objects observed by the Compton Gamma Ray Observatory (GRO) and air Cerenkov telescopes. This array and the future MILAGRO Water Cerenkov Detector can perform observations that are simultaneous with similar experiments to provide confirmation of emission, and can measure source spectra at a range of high energies previously unexplored

  12. Search for single sources of ultra high energy cosmic rays on the sky

    CERN Document Server

    Giacinti, G; Semikoz, D V

    2009-01-01

    In this paper we suggest a new way to identify single bright sources of UHECR on sky on top of background. We look for doublets of events at the highest energies, E > 6 X 10^19 eV, and identify low energy tails, mainly deflected by the regular Galactic Magnetic Field (GMF). With the parameters adopted in this paper, for 68% of reconstructed sources, angular position is less than one degree from real one. Reconstruction of the deflection power of magnetic field is strongly affected by the turbulent component of the GMF and for typical values of 4 muG near the Earth, one can reconstruct deflection power with 25% precision in 68% of cases.

  13. 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.

  14. Photon air showers at ultra-high energy and the photonuclear cross-section

    OpenAIRE

    Risse, M.; Homola, P.; Engel, R.; Gora, D.; Heck, D.; Pekala, J.; Wilczynska, B.; Wilczynski, H.

    2005-01-01

    Experimental conclusions from air shower observations on cosmic-ray photons above 10^19 eV are based on the comparison to detailed shower simulations. For the calculations, the photonuclear cross-section needs to be extrapolated over several orders of magnitude in energy. The uncertainty from the cross-section extrapolation translates into an uncertainty of the predicted shower features for primary photons and, thus, into uncertainties for a possible data interpretation. After briefly reviewi...

  15. On the interpretation of the cosmic-ray anisotropy at ultra-high energies

    OpenAIRE

    Gorbunov, D.S.; Tinyakov, P. G.; Tkachev, I. I.; Troitsky, S. V.

    2008-01-01

    A natural interpretation of the correlation between nearby Active Galactic Nuclei (AGN) and the highest-energy cosmic rays observed recently by the Pierre Auger Collaboration is that the sources of the cosmic rays are either AGN or other objects with a similar spatial distribution (the ``AGN hypothesis''). We question this interpretation. We calculate the expected distribution of the arrival directions of cosmic rays under the AGN hypothesis and argue that it is not supported by the data, one...

  16. Engine-driven Relativistic Supernovae as Sources of Ultra High Energy Cosmic Rays

    International Nuclear Information System (INIS)

    Understanding the origin of the highest energy cosmic rays is a crucial step in probing new physics at energies unattainable by terrestrial accelerators. Their sources remain an enigma half a century after their discovery. They must be accelerated in the local universe as otherwise interaction with cosmic background radiations would severely deplete the flux of protons and nuclei at energies above the Greisen-Zatsepin-Kuzmin (GZK) limit. Hypernovae, nearby GRBs, AGNs and their flares have all been suggested and debated in the literature as possible sources. Type Ibc supernovae have a local sub-population with mildly relativistic ejecta which are known to be sub-energetic GRBs or X-Ray Flashes for sometime and more recently as those with radio afterglows but without detected GRB counterparts, such as SN 2009bb. In this work we measure the size-magnetic field evolution, baryon loading and energetics of SN 2009bb using its radio spectra obtained with VLA and GMRT. We show that the engine-driven SNe lie above the Hillas line and they can explain the characteristics of post-GZK UHECRs.

  17. On ultra high energy cosmic rays and their resultant gamma rays

    CERN Document Server

    Gavish, Eyal

    2016-01-01

    The Fermi Large Area Telescope (Fermi LAT) collaboration has recently reported on 50 months of measurements of the isotropic Extragalactic Gamma Ray Background (EGRB) spectrum between $100\\mbox{MeV}$ and $820\\mbox{GeV}$. Ultrahigh Energy Cosmic Ray (UHECR) protons interact with the Cosmic Microwave Background (CMB) photons and produce cascade photons of energies $10\\mbox{MeV}\\mbox{-}1\\mbox{TeV}$ that contribute to the EGRB flux. We examine seven possible evolution models for UHECRs and find that UHECR sources that evolve as the Star Formation Rate (SFR), medium low luminosity active galactic nuclei type-1 ($L = 10^{43.5}\\mbox{erg sec}^{-1}$ in the $[0.5\\mbox{-}2]\\mbox{KeV}$ band), and BL Lacertae objects (BL Lacs) are the most acceptable given the constraints imposed by the observed EGRB. Other possibilities produce too much secondary $\\gamma$-radiation. In all cases, the decaying dark matter contribution improves the fit at high energy, but the contribution of still unresolved blazars, which would leave the ...

  18. 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.

  19. Ultra High Energy Cosmic Ray Acceleration in Engine-driven Relativistic Supernovae

    CERN Document Server

    Chakraborti, Sayan; Soderberg, Alicia; Loeb, Abraham; Chandra, Poonam

    2010-01-01

    The origin of the highest energy cosmic rays remains an enigma. They offer a window to new physics, including tests of physical laws relevant to their propagation and interactions, at energies unattainable by terrestrial accelerators. They must be accelerated locally, as otherwise background radiations would severely suppress the flux of protons and nuclei, at energies above the Greisen-Zatsepin-Kuzmin (GZK) limit. Nearby Gamma Ray Bursts (GRBs), Hypernovae, Active Galactic Nuclei (AGNs) and their flares, have all been suggested and debated as possible sources. A local sub-population of type Ibc supernovae (SNe) with mildly relativistic outflows have been detected as sub-energetic GRBs or X-Ray Flashes (XRFs) and recently as radio afterglows without detected GRB counterparts. We measure the size-magnetic field evolution, baryon loading and energetics, using the observed radio spectra of SN 2009bb. We place such engine-driven SNe above the Hillas line and establish that they can readily explain the post-GZK UH...

  20. Engine-driven Relativistic Supernovae as Sources of Ultra High Energy Cosmic Rays

    CERN Document Server

    Ray, Alak

    2011-01-01

    Understanding the origin of the highest energy cosmic rays is a crucial step in probing new physics at energies unattainable by terrestrial accelerators. Their sources remain an enigma half a century after their discovery. They must be accelerated in the local universe as otherwise interaction with cosmic background radiations would severely deplete the flux of protons and nuclei at energies above the Greisen-Zatsepin-Kuzmin (GZK) limit. Hypernovae, nearby GRBs, AGNs and their flares have all been suggested and debated in the literature as possible sources. Type Ibc supernovae have a local sub-population with mildly relativistic ejecta which are known to be sub-energetic GRBs or X-Ray Flashes for sometime and more recently as those with radio afterglows but without detected GRB counterparts, such as SN 2009bb. In this work we measure the size-magnetic field evolution, baryon loading and energetics of SN 2009bb using its radio spectra obtained with VLA and GMRT. We show that the engine-driven SNe lie above the...

  1. Ultra High Energy Cosmic Rays Spectra in Top-Down models

    International Nuclear Information System (INIS)

    In this work we present a detailed computation of the spectra of UHECR in the top-down scenario. We compare the spectra of hadrons obtained by two different methods in QCD and supersymmetric (SUSY) QCD with large primary energies s up to 1016 GeV. The two methods discussed are a Monte Carlo (MC) simulation and the evolution of the hadron fragmentation functions as described by the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equations. The hadron spectra obtained by the two methods agree fairly well in the interesting energy range 10-5MX X (MX is the energy scale of the process MX >= 1012 GeV). We have also computed the spectra of photons, neutrinos and nucleons obtaining a good agreement with other published results. The consistency of the spectra computed by different methods allows us to consider the spectral shape as a signature of the production model for UHECR, such as the decay of super heavy relic particles or topological defects

  2. 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...

  3. Mass entrainment and turbulence-driven acceleration of ultra-high energy cosmic rays in Centaurus A

    CERN Document Server

    Wykes, Sarka; Hardcastle, Martin J; Eilek, Jean A; Biermann, Peter L; Achterberg, Abraham; Bray, Justin D; Bicknell, Geoffrey V; Lazarian, Alex; Haverkorn, Marijke; Protheroe, Ray J; Bromberg, Omer

    2013-01-01

    Observations of the FR I radio galaxy Centaurus A in radio, X-ray and gamma-ray bands provide evidence for lepton acceleration up to several TeV and clues about hadron acceleration to tens of EeV. Synthesising the available observational constraints on the physical conditions and particle content in the jets, inner lobes and giant lobes of Centaurus A, we aim to evaluate its feasibility as an ultra-high-energy cosmic-ray source. We apply several methods of determining jet power and affirm the consistency of various power estimates of ~ 1 x 10^43 erg s^-1. Employing scaling relations based on the results of Laing & Bridle (2002), we estimate particle number densities in the jets, encompassing available radio through X-ray observations. Our model is compatible with the jets ingesting ~ 3 x 10^21 g s^-1 of matter via external entrainment from hot gas and ~ 7 x 10^22 g s^-1 via internal entrainment from jet-contained stars. This leads to an imbalance between the internal lobe pressure securable from radiating...

  4. 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.

  5. 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.

  6. Full-Sky Search for Ultra High Energy Cosmic Ray Anisotropies

    CERN Document Server

    Anchordoqui, L A; McCauley, T; Paul, T; Reucroft, S; Swain, J D; Widom, A; Anchordoqui, Luis A.; Hojvat, Carlos; McCauley, Thomas; Paul, Thomas; Reucroft, Stephen; Swain, John D.; Widom, Allan

    2003-01-01

    Using data from the SUGAR and the AGASA experiments taken during a 10 yr period with nearly uniform exposure to the entire sky, we search for anisotropy patterns in the arrival directions of cosmic rays with energies > 10^{19.6} eV. We determine the angular power spectrum from an expansion in spherical harmonics for modes out to \\ell=5. Based on available statistics, we find no significant deviation from isotropy. We compare the rather modest results which can be extracted from existing data samples with the results that should be forthcoming as new full-sky observatories begin operation.

  7. New Limits on the Ultra-high Energy Cosmic Neutrino Flux from the ANITA Experiment

    OpenAIRE

    ANITA collaboration; Gorham, P.; Allison, P.; Barwick, S.; Beatty, J; Besson, D; Binns, W; Chen, C.; Chen, P; Clem, J.; Connolly, A.; Dowkontt, P.; Duvernois, M.; Field, R.; Goldstein, D

    2008-01-01

    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 3 EeV. 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 candid...

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

    International Nuclear Information System (INIS)

    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. 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...

  10. Radio-detection of ultra-high energy cosmic rays. Analysis, simulation and interpretation

    International Nuclear Information System (INIS)

    Despite the use of giant detectors suitable for low flux beyond 1018 eV, the origin of ultra energy cosmic rays, remains unclear. In the 60', the radio-detection of air shower is proposed as a complementary technique to the ground particle detection and to the fluorescence method. A revival of this technique took place in the 2000's in particular with CODALEMA experiment. The first results show both a strong dependence of the signal to the geomagnetic field and a strong correlation between energy estimated by the radio-detectors and by particle detectors. The new generation of autonomous detectors created by the CODALEMA collaboration indicates that it is now possible to detect air showers autonomously. Due to the expected performances (a nearly 100% duty cycle, a signal generated by the complete shower, simplicity and low cost of a detector), it is possible to consider to deploy this technique for the future large arrays. In order to interpret experimental data, a simulation tool, SELFAS, is developed in this wok. This simulation code allowed us to highlight the existence of a second radio-emission mechanism. A first interpretation of the longitudinal profile as an observable of a privileged instant of the shower development is also proposed, which could give an estimation of the nature of the primary. (author)

  11. Observation of Ultra-high-energy Cosmic Rays with the ANITA Balloon-borne Radio Interferometer

    CERN Document Server

    Hoover, S; Gorham, P W; Grashorn, E; Allison, P; Barwick, S W; Beatty, J J; Belov, K; Besson, D Z; Binns, W R; Chen, C; Chen, P; Clem, J M; Connolly, A; Dowkontt, P F; DuVernois, M A; Field, R C; Goldstein, D; Vieregg, A G; Hast, C; Hebert, C L; Israel, M H; Javaid, A; Kowalski, J; Learned, J G; Liewer, K M; Link, J T; Lusczek, E; Matsuno, S; Mercurio, B C; Miki, C; Miočinović, P; Naudet, C J; Ng, J; Nichol, R J; Palladino, K; Reil, K; Romero-Wolf, A; Rosen, M; Ruckman, L; Saltzberg, D; Seckel, D; Varner, G S; Walz, D; Wu, F

    2010-01-01

    We report the observation of sixteen cosmic ray events of mean energy of $1.5 \\times 10^{19}$ eV, via radio pulses originating from the interaction of the cosmic ray air shower with the Antarctic geomagnetic field, a process known as geosynchrotron emission. We present the first ultra-wideband, far-field measurements of the radio spectral density of geosynchrotron emission in the range from 300-1000 MHz. The emission is 100% linearly polarized in the plane perpendicular to the projected geomagnetic field. Fourteen of our observed events are seen to have a phase-inversion due to reflection of the radio beam off the ice surface, and two additional events are seen directly from above the horizon.

  12. A cryogenically cooled, ultra-high-energy-resolution, trap-based positron beam

    International Nuclear Information System (INIS)

    A technique is described to produce a pulsed, magnetically guided positron beam with significantly improved beam characteristics over those available previously. A pulsed, room-temperature positron beam from a buffer gas trap is used as input to a trap that captures the positrons, compresses them both radially and axially, and cools them to 50 K on a cryogenic CO buffer gas before ejecting them as a pulsed beam. The total energy spread of the beam formed using this technique is 6.9 ± 0.7 meV FWHM, which is a factor of ∼5 better than the previous state-of-the-art, while simultaneously having sub-microsecond temporal resolution and millimeter spatial resolution. Possible further improvements in beam quality are discussed

  13. Ultra-high energy gamma-ray astronomy. From Tunka-HiSCORE to TAIGA

    Energy Technology Data Exchange (ETDEWEB)

    Tluczykont, Martin [Hamburg Univ., Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Collaboration: TAIGA collaboration

    2015-07-01

    In the past 3 years, the Tunka-HiSCORE collaboration has installed HiSCORE timing air Cherenkov detectors in the Tunka valley in Siberia. Since October 2013, a 9-station prototype array is in operation. These activities have merged into the recently founded TAIGA collaboration, which is currently building a non-imaging air Cherenkov array consisting today of 29 stations, which will be upgraded to 1 square-km. Furthermore, the deployment of a 4m diameter imaging air Cherenkov telescope is planned within 2015. Our aim is to combine the timing and imaging techniques on a large scale in order to optimize the air Cherenkov detection technique for energies above 10 TeV and up to several 100 TeV. Simulations show a clear potential of the planned hybrid event reconstruction. The status of our experiment and our future plans are presented.

  14. A cryogenically cooled, ultra-high-energy-resolution, trap-based positron beam

    Energy Technology Data Exchange (ETDEWEB)

    Natisin, M. R., E-mail: mnatisin@physics.ucsd.edu; Danielson, J. R.; Surko, C. M. [Department of Physics, University of California, San Diego, La Jolla, California 92093 (United States)

    2016-01-11

    A technique is described to produce a pulsed, magnetically guided positron beam with significantly improved beam characteristics over those available previously. A pulsed, room-temperature positron beam from a buffer gas trap is used as input to a trap that captures the positrons, compresses them both radially and axially, and cools them to 50 K on a cryogenic CO buffer gas before ejecting them as a pulsed beam. The total energy spread of the beam formed using this technique is 6.9 ± 0.7 meV FWHM, which is a factor of ∼5 better than the previous state-of-the-art, while simultaneously having sub-microsecond temporal resolution and millimeter spatial resolution. Possible further improvements in beam quality are discussed.

  15. 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.

  16. Magnetized target fusion: An ultra high energy approach in an unexplored parameter space

    International Nuclear Information System (INIS)

    Magnetized target fusion is a concept that may lead to practical fusion applications in a variety of settings. However, the crucial first step is to demonstrate that it works as advertised. Among the possibilities for doing this is an ultrahigh energy approach to magnetized target fusion, one powered by explosive pulsed power generators that have become available for application to thermonuclear fusion research. In a collaborative effort between Los Alamos and the All-Russian Scientific Institute for Experimental Physics (VNIIEF) a very powerful helical generator with explosive power switching has been used to produce an energetic magnetized plasma. Several diagnostics have been fielded to ascertain the properties of this plasma. We are intensively studying the results of the experiments and calculationally analyzing the performance of this experiment

  17. 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.

  18. Propagation of ultra-high energy neutrinos in the cosmic neutrino background

    International Nuclear Information System (INIS)

    UHE cosmic neutrino interaction with the cosmic neutrino background (CνB) is expected to produce absorption dips in the UHE neutrino flux at energies above the threshold for Z-boson resonant production. The observation of these dips would constitute an evidence for the existence of the CnuB; they could also be used to determine the value of the relic neutrino masses as well as some features of the population of UHE neutrino sources. After breafly discussing the current prospects for relic neutrino spectroscopy, we present a calculation of the UHE neutrino transmission probability based on finite-temperature field theory which takes into account the thermal motion of the relic neutrinos. We then compare our results with the approximate expressions existing in the literature and discuss the influence of thermal effects on the absorption dips in the context of realistic UHE neutrino fluxes and favoured neutrino mass schemes

  19. Report of the Working Group on the Composition of Ultra High Energy Cosmic Rays

    CERN Document Server

    Abbasi, R; Belz, J; de Souza, V; Hanlon, W; Ikeda, D; Lundquist, J P; Sokolsky, P; Stroman, T; Tameda, Y; Tsunesada, Y; Unger, M

    2015-01-01

    For the first time a proper comparison of the average depth of shower maximum ($X_{\\rm max}$) published by the Pierre Auger and Telescope Array Observatories is presented. The $X_{\\rm max}$ distributions measured by the Pierre Auger Observatory were fit using simulated events initiated by four primaries (proton, helium, nitrogen and iron). The primary abundances which best describe the Auger data were simulated through the Telescope Array (TA) Middle Drum (MD) fluorescence and surface detector array. The simulated events were analyzed by the TA Collaboration using the same procedure as applied to their data. The result is a simulated version of the Auger data as it would be observed by TA. This analysis allows a direct comparison of the evolution of $\\langle X_{\\rm max} \\rangle$ with energy of both data sets. The $\\langle X_{\\rm max} \\rangle$ measured by TA-MD is consistent with a preliminary simulation of the Auger data through the TA detector and the average difference between the two data sets was found to...

  20. Infinite efficiency of collisional Penrose process: Can over-spinning Kerr geometry be the source of ultra-high-energy cosmic rays and neutrinos ?

    CERN Document Server

    Patil, Mandar

    2015-01-01

    The origin of the ultra-high-energy particles we receive on the Earth from the outer space such as EeV cosmic rays and PeV neutrinos remains an enigma. All mechanisms known to us currently make use of electromagnetic interaction to accelerate charged particles. In this paper we propose a mechanism exclusively based on gravity rather than electromagnetic interaction. We show that it is possible to generate ultra-high-energy particles starting from particles with moderate energies using the collisional Penrose process in an overspinning Kerr spacetime transcending the Kerr bound only by an infinitesimal amount, i.e., with the Kerr parameter $a=M(1+\\epsilon)$, where we take the limit $\\epsilon \\rightarrow 0^+$. We consider two massive particles starting from rest at infinity that collide at $r=M$ with divergent center-of-mass energy and produce two massless particles. We show that massless particles produced in the collision can escape to infinity with the ultra-high energies exploiting the collisional Penrose p...

  1. Evidence for long-term variability in the ultra high energy photon flux from Cygnus X-3

    International Nuclear Information System (INIS)

    A time-correlation analysis of atmospheric Cerenkov pulses by a wide-angle photomultiplier system was previously shown to have present in it a nonrandom component which seemed associated with the Right Ascension (RA) range approx. 20+or-04h. A recent examination of multi-muon events recorded by a photon-decay detector shows a similar time-dependent effect, closely matching the previous results, supporting the suggestion that the effect is of cosmic origin. However, even though Cyg. X-3 lies well inside the region of peak intensity, it does not seem possible to ascribe to it the whole effect, for the implied photon flux appears too large to be reconciled to various gamma-ray measurements of Cyg. X-3. The original data were subjected to a phase-histogram analysis and it as found that only 2.5% of overall recorded data are compatible with a phase-dependent emission from Cyg. X-3. Assuming these events to be gamma rays yields a detected flux of (2.6 + or - 0.3) x 10 to the minus 12th power gamma cm -2s-1 above 5 x 10 to the 14th power eV. Comparing this value with more recent ultra high energy (UHE) photon data from the same source, it is suggested that the available data generally favor a long-term reduction in the Cyg. X-3 inferred luminosity ( 10 to the 13th power eV) by a factor of (1.8 + or - 0.3) per year

  2. Ultra-high-energy neutrinos and cosmic rays from gamma-ray bursts. Exploring and updating the connection

    International Nuclear Information System (INIS)

    It is natural to consider the possibility that the most energetic particles detected (>1018 eV), ultra-high-energy cosmic rays (UHECRs), are originated at the most luminous transient events observed (>1052 erg s-1), gamma-ray bursts (GRBs). As a result of the interaction of highly-accelerated, magnetically-confined protons and ions with the photon field inside the burst, both neutrons and UHE neutrinos are expected to be created: the former escape the source and beta-decay into protons which propagate to Earth, where they are detected as UHECRs, while the latter, if detected, would constitute the smoking gun of hadronic acceleration in the sources. Recently, km-scale neutrino telescopes such as IceCube have finally reached the sensitivities required to probe the neutrino predictions of some of the existing GRB models. On that account, we present here a revised, self-consistent model of joint UHE proton and neutrino production at GRBs that includes a state-of-the-art, improved numerical calculation of the neutrino flux (NeuCosmA); that uses a generalised UHECR emission model where some of the protons in the sources are able to ''leak out'' of their magnetic confinement before having interacted; and that takes into account the energy losses of the protons during their propagation to Earth. We use our predictions to take a close look at the cosmic ray-neutrino connection and find that the current UHECR observations by giant air shower detectors, together with the upper bounds on the flux of neutrinos from GRBs, are already sufficient to put tension on several possibilities of particle emission and propagation, and to point us towards some requirements that should be fulfilled by GRBs if they are to be the sources of the UHECRs. We further refine our analysis by studying a dynamical burst model, where we find that the different particle species originate at distinct stages of the expanding GRB, each under particular conditions. Finally, we consider

  3. The energy spectrum observed by the AGASA experiment and the spatial distribution of the sources of ultra-high energy cosmic rays

    CERN Document Server

    Medina-Tanco, G A

    1999-01-01

    Seven and a half years of continuous monitoring of giant air showers triggered by ultra high-energy cosmic rays have been recently summarized by the AGASA collaboration. The resulting energy spectrum indicates clearly that the cosmic ray spectrum extends well beyond the Greisen-Zatsepin-Kuzmin (GZK) cut-off at $\\sim 5 \\times 10^{19}$ eV. Furthermore, despite the small number statistics involved, some structure in the spectrum may be emerging. Using numerical simulations, it is demonstrated in the present work that these features are consistent with a spatial distribution of sources that follows the distribution of luminous matter in the local Universe. Therefore, from this point of view, there is no need for a second high-energy component of cosmic rays dominating the spectrum beyond the GZK cut-off.

  4. 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.

  5. 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.

  6. Propagation of Ultra-High Energy Cosmic Rays above $10^{19}$ eV in a Structured Extragalactic Magnetic Field and Galactic Magnetic Field

    OpenAIRE

    Takami, Hajime; Yoshiguchi, Hiroyuki; Sato, Katsuhiko

    2005-01-01

    We present numerical simulations on propagation of Ultra-High Energy Cosmic Rays (UHECRs) above $10^{19}$ eV in a structured extragalactic magnetic field (EGMF) and simulate their arrival distributions at the earth. We use the IRAS PSCz catalogue in order to construct a model of the EGMF and source models of UHECRs, both of which reproduce the local structures observed around the Milky Way. We also consider modifications of UHECR arrival directions by the galactic magnetic field. We follow an...

  7. The Search for Anisotropy in the Arrival Directions of Ultra-High Energy Cosmic Rays Observed by the High Resolution Fly's Eye Detector in Monocular Mode

    International Nuclear Information System (INIS)

    The High Resolution Fly's Eye HiRes-I detector has now been in operation in monocular mode for over six years. During that time span, HiRes-I has accumulated a larger exposure to Ultra-High Energy Cosmic Rays (UHECRs) above 1019 eV than any other experiment built to date. This presents an unprecedented opportunity to search for anisotropy in the arrival directions of UHECRs. We present results of a search for dipole distributions oriented towards major astrophysical landmarks and a search for small-scale clustering. We conclude that the HiRes-I data set is, in fact, consistent with an isotropic source model

  8. 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 ...

  9. Ultra-high vacuum

    CERN Document Server

    Fischer, E

    1974-01-01

    This paper mentions first the requirement of ultra-high vacuum (UHV) for storage rings with colliding beams, and then describes how, in the mid-1950's, the fast development of UHV technology made the construction of the Intersecting Storage Rings (ISR) possible with their 2 km of vacuum pipes at 10/sup -11/ Torr. The performance features are discussed with special emphasis on the problem of stimulated gas desorption from chamber walls. The placing of contracts for sputter-ion pumps and the need for developing sector valves at CERN is mentioned to illustrate that there was some feedback from these constructions to the general development of UHV. Finally, some problems and solutions are listed which are common to other fields where UHV is used: namely in thermonuclear fusion, space research, and manufacturing of integrated circuits.

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

    OpenAIRE

    Abu-Zayyad, T.; Aida, R.; Allen, M.; Anderson, R; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; B.G. Cheon; Chiba, J.; Chikawa, M.; Cho, E. J.; Cho, W. R.

    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 ...

  11. 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.

  12. A search for sources of ultra high energy gamma rays at air shower energies with Ooty EAS array

    Science.gov (United States)

    Tonwar, S. C.; Gopalakrishnan, N. V.; Sreekantan, B. V.

    1985-01-01

    A 24 detector extensive air shower array is being operated at Ootacamund (2200 m altitude, 11.4 deg N latitude) in southern India to search for sources of Cosmic gamma rays of energies greater then 5 x 10 to the 13th power eV. The angular resolution of the array has been experimentally estimated to be better than about 2 deg. Since June '84, nearly 2.5 million showers have been collected and their arrival directions determined. These showers are being studied to search for very high energy gamma ray emission from interesting astrophysical objects such as Cygnus X-3, Crab pulsar and Geminga.

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

    International Nuclear Information System (INIS)

    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 ∼35 keV/nucleon from the interactions of 400 MeV/nucleon 16O with natXe gas targets

  14. Microstructure of X210Cr12 steel after the forming in semi-solid state visualized by very low energy SEM in ultra high vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Mikmeková, Š., E-mail: sarka@isibrno.cz [Institute of the Scientific Instruments of the ASCR, v.v.i., Královopolská 147, Brno 612 64 (Czech Republic); Mašek, B.; Jirková, H.; Aišman, D. [University of West Bohemia in Pilsen, Research Centre of Forming Technology – FORTECH, Univerzitni 22, 306 14 Pilsen (Czech Republic); Müllerová, I.; Frank, L. [Institute of the Scientific Instruments of the ASCR, v.v.i., Královopolská 147, Brno 612 64 (Czech Republic)

    2013-06-15

    Progress in materials science is inseparably connected with development of new analytical methods which make possible to observe the materials microstructure with high sensitivity. The aim of the present study is shown that scanning low energy electron microscopy (SLEEM) has a significant impact in advance of a fundamental understanding of the evolution of microstructure upon semi-solid processing. This paper deals with the application of the ultra high vacuum scanning low energy electron microscopy (UHV SLEEM) to the study of microstructure of X210Cr12 steel after the formation in semi-solid state and the study of the annealing of deformed metastable austenite. Examples from these specimens show that the contrast between differently oriented grains in polycrystalline materials is very sensitive to the parameters such as energy of the primary beam, working distance and detection of high angle backscattered electrons.

  15. 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.

  16. High energy mechanical milling of ultra-high molecular weight polyethylene (UHMWPE);Processamento de polietileno de ultra-alta massa molar (PEUAMM) por moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Melina C.; Mendes, Luciana B.; Carvalho, Benjamim M.; Pinheiro, Luis A.; Cintho, Osvaldo M., E-mail: melina152000@yahoo.com.b [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil); Capocchi, Jose D.T.; Kubaski, Evaldo T. [Universidade de Sao Paulo (USP), SP (Brazil)

    2009-07-01

    Ultra-high molecular weight polyethylene (UHMWPE) is a polyethylene with a very long chain, which provides excellent features, but makes the processing difficult due to high melt viscosity. Many studies intend to found out means to make its processing easier. Recently, the high energy mechanical milling has been used for polymeric materials and it was detected that physical and chemical changes occur during milling. In such case, powder of UHMWPE was milled in three types of mills: SPEX, attritor e planetary, in different times of milling. The milling temperatures were measured during processing. The polymer was characterized by SEM, DSC and XRD, and the deconvolution of x-ray diffractograms was made. Thus, it was observed that the material processed in attritor mill showed larger phase transformation from orthorhombic to monoclinic. This is most likely due to the smaller milling temperature of attritor mill when compared with the other two mills and the high shear force generated during milling. (author)

  17. 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.

  18. 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. PMID:27030316

  19. Atmospheric aerosols at the Pierre Auger Observatory: characterization and effect on the energy estimation for ultra-high energy cosmic rays

    International Nuclear Information System (INIS)

    The Pierre Auger Observatory, located in the Province of Mendoza in Argentina, is making good progress in understanding the nature and origin of the ultra-high energy cosmic rays. Using a hybrid detection technique, based on surface detectors and fluorescence telescopes, it provides large statistics, good mass and energy resolution, and solid control of systematic uncertainties. One of the main challenges for the fluorescence detection technique is the understanding of the atmosphere, used as a giant calorimeter. To minimize as much as possible the systematic uncertainties in fluorescence measurements, the Auger Collaboration has developed an extensive atmospheric monitoring program. The purpose of this work is to improve our knowledge of the atmospheric aerosols, and their effect on fluorescence light propagation. Using a modelling program computing air mass displacements, it has been shown that nights with low aerosol concentrations have air masses coming much more directly from the Pacific Ocean. For the first time, the effect of the aerosol size on the light propagation has been estimated. Indeed, according to the Ramsauer approach, large aerosols have the largest effect on the light scattering. Thus, the dependence on the aerosol size has been added to the light scattering parameterizations used by the Auger Collaboration. A systematic overestimation of the energy and of the maximum air shower development Xmax is observed. Finally, a method based on the very inclined laser shots fired by the Auger central laser has been developed to estimate the aerosol size. Large aerosol sizes ever estimated at the Pierre Auger Observatory can now be probed. First preliminary results using laser-shot data collected in the past have identified a population of large aerosols. (author)

  20. 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...

  1. Estimating Ultra-High Energy Cosmic Ray Data as seen from the JEM-EUSO Fluorescence Detector for the planned space based JEM-EUSO detector

    Science.gov (United States)

    Fenn, Jeremy; Wiencke, Lawrence

    2014-03-01

    Ultra-high energy cosmic rays (UHECRs) are subatomic particles with energies above 1018 eV. UHECRs are of interest because they are the highest energy particles known to exist. Their source(s), compositions, and the acceleration mechanisms to produce them with energies beyond 1020 eV remain unknown. The Pierre Auger Observatory, located in Argentina, is the world's largest UHECR observatory. It is one of the few a hybrid detectors in the world that combines surface (SD) and fluorescence (FD) detectors. The hybrid detection system is advantageous as it provides a more accurate reconstruction of the incoming cosmic ray's energy and trajectory as it travels through the atmosphere. However, even with the advantage of a hybrid detector, the Pierre Auger has limitations being a ground based observatory. The next generation in UHECR detection is the planned JEM-EUSO mission. The JEM-EUSO mission will consist of a fluorescence detector telescope attached to the International Space Station (ISS). The JEM-EUSO detector is expected to receive an exposure level to UHECRs many times that of the Pierre Auger Observatory by viewing a much larger volume of the atmosphere. In this presentation, I will discuss how data from specific UHECRs collected by the Pierre Auger Observatory is analyzed and altered to estimate what their signatures would look like from space at the planned JEM-EUSO detector. Research advisor

  2. Near-threshold production of $W^\\pm$, $Z^0$ and $H^0$ at a fixed-target experiment at the future ultra-high-energy proton colliders

    CERN Document Server

    Lansberg, J P; Uggerhøj, U I

    2015-01-01

    We outline the opportunities to study the production of the Standard Model bosons, $W^\\pm$, $Z^0$ and $H^0$ at "low" energies at fixed-target experiments based at possible future ultra-high-energy proton colliders, \\ie\\ the High-Energy LHC, the Super proton-proton Collider and the Future Circular Collider -- hadron-hadron. These can be indeed made in conjunction with the proposed future colliders designed to reach up to $\\sqrt{s}=100$ TeV by using bent crystals to extract part of the halo of the beam which would then impinge on a fixed target. Without disturbing the collider operation, this technique allows for the extraction of a substantial amount of particles in addition to serve for a beam-cleaning purpose. With this method, high-luminosity fixed-target studies at centre-of-mass energies above the $W^\\pm$, $Z^0$ and $H^0$ masses, $\\sqrt{s} \\simeq 170-300$ GeV, are possible. We also discuss the possibility offered by an internal gas target, which can also be used as luminosity monitor by studying the beam ...

  3. Characteristics of geomagnetic cascading of ultra-high energy photons at the southern and northern sites of the Pierre Auger Observatory

    CERN Document Server

    Homola, P; Engel, R; Gora, D; Pekala, J; Wilczynska, B; Wilczynski, H

    2006-01-01

    Cosmic-ray photons above 10^19 eV can convert in the geomagnetic field and initiate a preshower, i.e. a particle cascade before entering the atmosphere. We compare the preshower characteristics at the southern and northern sites of the Pierre Auger Observatory. In addition to a shift of the preshower patterns on the sky due to the different pointing of the local magnetic field vectors, the fact that the northern Auger site is closer to the geomagnetic pole results in a different energy dependence of the preshower effect: photon conversion can start at smaller energies, but full conversion is reached for the whole sky at higher energies compared to the southern Auger site. We show how the complementary preshower features at the two sites can be used to search for ultra-high energy photons among cosmic rays. In particular, the different preshower characteristics at the northern Auger site may provide an elegant and unambiguous confirmation if a photon signal is detected at the southern site.

  4. Effect of MoSi2 addition on densification and properties of ultra high temperature ceramics produced by pressureless sintering

    OpenAIRE

    Silvestroni, Laura

    2007-01-01

    Ultra high temperature ceramics are a class of material of great interest thanks to their combination of engineering properties such as high melting point, good thermochemical and thermomechanical properties in aggressive environment. Potential applications of these materials are forecast in aerospace industry and in industrial sectors like metallurgy, energy and power production.. To ensure that good properties are attained, control of densification and microstructure is necessary. Because o...

  5. Study of the composition of ultra-high energy cosmic rays detected by the Pierre Auger Observatory and analysis of the associated hadronic mechanisms

    International Nuclear Information System (INIS)

    Ultra high energy cosmic rays (UHECR), i.e. E ≥ 1 EeV, raise many questions about their origin and constitute a challenge to modern physics. These cosmic rays entering the atmosphere dissipate their huge energy by generating a shower of secondary particles whose development is significantly different depending on the nature of the primaries. The study of the composition of UHECR is therefore a major interest both in understanding the hadronic processes which govern the evolution of showers and in identifying the sources of this radiation. Given its hybrid structure and the size of its unmatched network of ground detectors, the Pierre Auger Observatory can provide clear answers to the issues raised by UHECR. In this thesis, we are particularly interested in the muon component of air showers. First, we show how the hadronic parameters define the production of muons. Then we present an original method to extract this muon component and deduce the implications on the composition of UHECR. The results of this approach suggest a transition from a heavy composition to a light one when the energy increases. Finally, we address the measurement of cosmic-air cross section and present the first results derived from the Pierre Auger Observatory data. (author)

  6. Charm decay in slow-jet supernovae as the origin of the IceCube ultra-high energy neutrino events

    CERN Document Server

    Bhattacharya, Atri; Reno, Mary Hall; Sarcevic, Ina

    2014-01-01

    We investigate whether the recent ultra-high energy (UHE) neutrino events detected at the IceCube neutrino observatory could come from the decay of charmed mesons produced within the mildly relativistic jets of supernova-like astrophysical sources. We demonstrate that the $5.7\\sigma$ excess of neutrinos observed by IceCube in the energy range 30 TeV--2 PeV can be explained by a diffuse flux of neutrinos produced in such slow-jet supernovae, using the values of astrophysical and QCD parameters within the theoretical uncertainties associated with neutrino production from charmed meson decay in astrophysical sources. We discuss the theoretical uncertainties inherent in the evaluation of charm production in high energy hadronic collisions, as well as the astrophysical uncertainties associated with slow-jet supernova sources. The proton flux within the source, and therefore also the produced neutrino flux, is cut off at around a few PeV, when proton cooling processes become dominant over proton acceleration. This ...

  7. CORRELATIONS OF THE ARRIVAL DIRECTIONS OF ULTRA-HIGH ENERGY COSMIC RAYS WITH EXTRAGALACTIC OBJECTS AS OBSERVED BY THE TELESCOPE ARRAY EXPERIMENT

    International Nuclear Information System (INIS)

    We search for correlations between the positions of extragalactic objects and the arrival directions of ultra-high energy cosmic rays (UHECRs) with primary energy E ≥ 40 EeV as observed by the surface detector array of the Telescope Array (TA) experiment during the first 40 months of operation. We examine several public astronomical object catalogs, including the Veron-Cetty and Veron catalog of active galactic nuclei. We count 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 the combination of these parameters that maximizes the correlations, and we calculate the probability 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 catalogs are taken into account

  8. 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...

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

    International Nuclear Information System (INIS)

    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

  10. 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.

  11. A composition study of ultra high energy cosmic rays using timing information from the 750m infill array of the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    The Pierre Auger Observatory is a hybrid detector for the purpose of detecting extensive air showers from ultra high energy cosmic rays (UHECR). It consists of an array of water cherenkov detectors, the surface detector (SD), and atmospheric fluorescence telescopes, the fluorescence detector. The determination of the mass composition of UHECR is one of its main tasks and may give important hints on their sources and accelerators. One approach to deduce it from data of the SD is to use the risetime, the time it takes for the integrated signal of a surface detector station to rise from 10% to 50% of its final value. For the 750 m infill array, that was commissioned in 2008 as a part of the AMIGA extension and makes energies below 1 EeV accessible to the SD, risetime studies have yet to be performed. To use risetime for the determination of mass composition one has to condense the information of the stations from a single event to one mass sensitive observable that can be compared with simulations. Therefore risetime has to be corrected for azimuthal asymmetry, furthermore its dependance on the distance to the shower core and zenith angle has to be taken into account. Details on the implementation and the results are shown.

  12. Cosmic Ray Origin: Lessons from Ultra-High-Energy Cosmic Rays and the Galactic/Extragalactic Transition

    International Nuclear Information System (INIS)

    We examine the question of the origin of the Galactic cosmic-rays (GCRs) in the light of the data available at the highest energy end of the spectrum. We argue that the data of the Pierre Auger Observatory and of the KASCADE-Grande experiment suggest that the transition between the Galactic and the extragalactic components takes place at the energy of the ankle in the all-particle cosmic-ray spectrum, and at an energy of the order of 1017 eV for protons. Such a high energy for Galactic protons appears difficult to reconcile with the general view that GCRs are accelerated by the standard diffusive shock acceleration process at the forward shock of individual supernova remnants (SNRs). We also review various difficulties of the standard SNR-GCR connection, related to the evolution of the light element abundances and to significant isotopic anomalies. We point out that most of the power injected by the supernovæ in the Galaxy is actually released inside superbubbles, which may thus play an important role in the origin of cosmic-rays, and could solve some persistent problems of the standard SNR-GCR scenario in a rather natural way

  13. On the Possibility of Radar Detection of Ultra-high Energy Cosmic Ray- and Neutrino-induced Air Showers

    Science.gov (United States)

    Gorham, P.

    1999-01-01

    We show that cosmic rays air showers resulting from primaries with energies above 10(sup 19) eV should be straightforward to detect with radar ranging techniques, where the radar echoes are produced by scattering from the column of ionized air produced by the shower.

  14. Cosmic Ray Origin: Lessons from Ultra-High-Energy Cosmic Rays and the Galactic/Extragalactic Transition

    Energy Technology Data Exchange (ETDEWEB)

    Parizot, Etienne

    2014-11-15

    We examine the question of the origin of the Galactic cosmic-rays (GCRs) in the light of the data available at the highest energy end of the spectrum. We argue that the data of the Pierre Auger Observatory and of the KASCADE-Grande experiment suggest that the transition between the Galactic and the extragalactic components takes place at the energy of the ankle in the all-particle cosmic-ray spectrum, and at an energy of the order of 10{sup 17} eV for protons. Such a high energy for Galactic protons appears difficult to reconcile with the general view that GCRs are accelerated by the standard diffusive shock acceleration process at the forward shock of individual supernova remnants (SNRs). We also review various difficulties of the standard SNR-GCR connection, related to the evolution of the light element abundances and to significant isotopic anomalies. We point out that most of the power injected by the supernovæ in the Galaxy is actually released inside superbubbles, which may thus play an important role in the origin of cosmic-rays, and could solve some persistent problems of the standard SNR-GCR scenario in a rather natural way.

  15. Cosmic Ray Origin: Lessons from Ultra-High-Energy Cosmic Rays and the Galactic/Extragalactic Transition

    CERN Document Server

    Parizot, Etienne

    2014-01-01

    We examine the question of the origin of the Galactic cosmic-rays (GCRs) in the light of the data available at the highest energy end of the spectrum. We argue that the data of the Pierre Auger Observatory and of the KASCADE-Grande experiment suggest that the transition between the Galactic and the extragalactic components takes place at the energy of the ankle in the all-particle cosmic-ray spectrum, and at an energy of the order of $10^{17}$ eV for protons. Such a high energy for Galactic protons appears difficult to reconcile with the general view that GCRs are accelerated by the standard diffusive shock acceleration process at the forward shock of individual supernova remnants (SNRs). We also review various difficulties of the standard SNR-GCR connection, related to the evolution of the light element abundances and to significant isotopic anomalies. We point out that most of the power injected by the supernovae in the Galaxy is actually released inside superbubbles, which may thus play an important role i...

  16. Silicon detectors: damage, modelling and expected long-time behaviour in physics experiments at ultra high energy

    CERN Document Server

    Lazanu, I; Lazanu, Ionel; Lazanu, Sorina

    2007-01-01

    In this contribution, the structural modifications of the material and the degradation of devices is modelled and compared with experimental data for more resistivities, temperatures, crystal orientations and oxygen concentrations, considering the existence of the new primary fourfold coordinated defect, besides the vacancy and the interstitial. Some estimations of the behaviour of detectors in concrete environments at the next generations of high energy physics experiments as LHC, SLHC, VLHC, or ULHC are done.

  17. Physical conditions in nearby active galaxies correlated with ultra-high-energy cosmic rays detected by the Pierre Auger Observatory

    OpenAIRE

    Gureev, Sergey; Troitsky, Sergey

    2008-01-01

    We analyze the active-galaxy correlation reported in 2007 by the Pierre Auger Collaboration. The signal diminishes if the correlation-function approach (counting all "source-event" pairs and not only "nearest neighbours") is used, suggesting that the correlation may reveal individual sources and not their population. We analyze available data on physical conditions in these individual correlated sources and conclude that acceleration of protons to the observed energies is hardly possible in a...

  18. Search for correlations of the arrival directions of ultra-high energy cosmic rays with specific point source candidates

    International Nuclear Information System (INIS)

    A search has been made for correlations between the arrival directions of cosmic rays above 1019 eV and various classes of galactic and extragalactic point source candidates. The effects that the galactic and intergalactic magnetic fields would have on their arrival directions and times of flight have been considered. Although some statistical indications for directional correlations have been found, none is significant enough to give strong support to any specific model of the origin of high energy cosmic rays. (orig.)

  19. Precise measurement of the absolute fluorescence yield of nitrogen in air. Consequences on the detection of ultra-high energy cosmic rays

    International Nuclear Information System (INIS)

    The study of the energy spectrum of ultra-high energy cosmic rays (E > 1020 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)

  20. Propagation of Ultra-High Energy Cosmic Rays above $10^{19}$ eV in a Structured Extragalactic Magnetic Field and Galactic Magnetic Field

    CERN Document Server

    Takami, H; Sato, K; Takami, Hajime; Yoshiguchi, Hiroyuki; Sato, Katsuhiko

    2006-01-01

    We present numerical simulations on propagation of Ultra-High EnergyCosmic Rays (UHECRs) above $10^{19}$ eV in a structured extragalactic magnetic field (EGMF) and simulate their arrival distribution at the earth. We use the IRAS PSCz catalogue in order to construct a model of the EGMF and source model of UHECRs, both of which reproduce the local structures around the Milky Way. We also consider modifications of UHECR arrival directions by the Galactic magnetic field. We follow an inverse process of their propagation from the earth and record the trajectories. This enables us to calculate only trajectories of UHECRs arriving at the earth, which saves the CPU time. We construct arrival distribution of UHECRs from these trajectories and calculate the harmonic amplitudes and the two point correlation functions of their arrival distribution using our source models. We estimate number density of sources which explains the Akeno Ground Air Shower Array observation best. As a result, we find that $\\sim 5 \\times 10^{...

  1. Propagation of extragalactic ultra-high energy cosmic-ray nuclei : implications for the observed spectrum and composition

    OpenAIRE

    Allard, D.

    2009-01-01

    In this paper, we study the propagation of cosmic-ray nuclei and protons. We emphasize the influence of the source composition on the expected spectrum and composition on Earth as well as on the phenomenology of the transition from Galactic to extragalactic cosmic-rays and the interpretation of the ankle. We point out that the different source composition models cannot be distinguished on the sole basis of the cosmic-ray spectrum but that the the energy evolution of $$ should remove this dege...

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

    OpenAIRE

    Arganda, E.; Arqueros Martínez, Fernando; Blanco Ramos, Francisco; García Pinto, Diego; Ortiz Ramis, Montserrat; Rosado Vélez, Jaime; Vázquez Peñas, José Ramón

    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 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 ener...

  3. 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.

  4. 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.

  5. Proton-proton, pion-proton and pion-pion diffractive collisions at ultra-high energies

    CERN Document Server

    Anisovich, V V; Nikonov, V A; Nyiri, J

    2014-01-01

    The LHC energies are those at which the asymptotic regime in hadron-hadron diffractive collisions ($pp,\\pi p,\\pi\\pi$) might be switched on. Based on results of the Dakhno-Nikonov eikonal model which is a generalization of the Good-Walker eikonal approach for a continuous set of channels, we present a picture for transformation of the constituent quark mode to the black disk one. In the black disk mode ($\\sqrt s \\geq 10$ TeV) we have a growth of the logarithm squared type for total and elastic cross sections, $\\sigma_{tot}\\sim\\ln^2s$ and $\\sigma_{el}\\sim\\ln^2s$, and $(\\tau={\\bf q}_\\perp^2\\sigma_{tot})$-scaling for diffractive scattering and diffractive dissociation of hadrons. The diffractive dissociation cross section grows as $\\sigma_{D}\\sim\\ln{s}$, $\\sigma_{DD}\\sim\\ln{s}$, and their relative contribution tends to zero: $\\sigma_{D}/\\sigma_{tot}\\to 0$, $\\sigma_{DD}/\\sigma_{tot}\\to 0$. Asymptotic characteristics of diffractive and total cross sections are universal, and this results in the asymptotical equalit...

  6. Non-universal spectra of ultra-high energy cosmic ray primaries and secondaries in a structured universe

    International Nuclear Information System (INIS)

    Analytical calculations of extra-galactic cosmic ray spectra above ∼ 1017 eV are often performed assuming continuous source distributions, giving rise to spectra that depend little on the propagation mode, be it rectilinear or diffusive. We perform trajectory simulations for proton primaries in the probably more realistic case of discrete sources with a density of ∼ 10-5 Mpc-3. We find two considerable non-universal effects that depend on source distributions and magnetic fields: First, the primary extra-galactic cosmic ray flux can become strongly suppressed below a few 1018 eV due to partial confinement in magnetic fields surrounding sources. Second, the secondary photon to primary cosmic ray flux ratio between ≅ 3 x 1018 eV and ≅ 1020 eV decreases with decreasing source density and increasing magnetization. As a consequence, in acceleration scenarios for the origin of highest energy cosmic rays the fraction of secondary photons may be difficult to detect even for experiments such as Pierre Auger. The cosmogenic neutrino flux does not significantly depend on source density and magnetization. (author)

  7. Ultra High Energy Cosmic Rays and Atmospheric Monitoring of Air-Fluorescence and Air-Cherenkov Telescopes Via High Spectral Resolution Lidar

    International Nuclear Information System (INIS)

    In this work, we give first a review of Ultra High Energy Cosmic Rays (UHECR), with consideration to their origins, composition, acceleration mechanism and an introduction to present and future experiments for such studies. We describe the role of troposphere as a medium responsible for the production of Extensive Air Showers focusing in the characteristics of 3 components: electromagnetic, hadronic and muonic and we explain the production of air-fluorescence and Cherenkov radiation, as well as corresponding simulation codes. We discuss the origins of the needed correction of the overall UHECR signal recorded by EAS telescopes due to scattering of air-Cherenkov and air-fluorescence radiation by molecular and aerosol particulates of the atmosphere. Therefore we explain the necessity of using advanced and at the same time reasonable cost LIDARS for quantification of aerosol to molecular scattering ratio. On the experimental side, we present a prototype of High Spectral Resolution Lidar (HSRL) in bi static mode with laser emitter at 532 nm and telescope receiver hosting two Fabry-Perot etalons, needed for the molecular and aerosol channels, respectively. We present experimental results on the characterization of each of the two channels and an algorithm for extraction of the aerosol to molecular scattering ratio. Finally, we give some preliminary report on our plans on using, as alternative to Fabry-Perot etalons, Atomic and Molecular Absorption Filters. In this way, the atomic vapor version of the HSRL replaces the temperature and mechanically sensitive Fabryperot with a robust and stable atomic or molecular absorption filter.

  8. Energy dissipation study of ultra high performance concrete columns under blast loading%爆炸荷载作用下超高性能钢筋混凝土柱的耗能机理研究

    Institute of Scientific and Technical Information of China (English)

    郭红梅; 田慧; 张海; 徐慎春

    2015-01-01

    In order to investigate the explosion resistance performance of ultra-high performance reinforced concrete,the ultra high performance concrete( UHPC)column energy dissipation mechanism was objected to study under the blast loading. Accurate numerical models was set up by the finite element software LS-DYNA can be used to analyze the total energy of ultra-high performance con-crete columns and the variation disciplines of each component of energy. The results show that the energy change of UHPC column is closely related to the stress-wave propagation with the blast loading. The majority of the energy was occupied by the UHPC and the rest energy was hold by the fixture. In the total energy,internal energy is the most,kinetic energy is the more. Hourglass energy is the minimized. Therefore the key to the antiknock ability of ultra-high performance reinforced concrete columns is the performance of ultra-high performance concrete.%为了进一步明确超高性能钢筋混凝土的抗爆性能,以超高性能钢筋混凝土柱为研究对象,研究其在爆炸荷载作用下的耗能机理。利用有限元软件LS-DYNA建立精细化数值模型,分析了爆炸荷载作用下超高性能混凝土柱的总能量及各组分能量的变化规律,从而得出其耗能规律。研究结果表明:爆炸冲击波作用下,超高性能钢筋混凝土柱中能量变化与应力波传播密切相关;超高性能钢筋混凝土能量占据柱结构能量的绝大部分,钢筋仅仅占据了其很少部分的能量;总能量中以内能最大,动能次之,沙漏能最小。因此,对于超高性能钢筋混凝土柱的抗爆能力而言,超高性能混凝土的性能作用十分关键。

  9. 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.

  10. Study on a multi-messenger basis and phenomenology of the sources of ultra-high energy cosmic rays: the pierre auger observatory contribution

    International Nuclear Information System (INIS)

    The field of Ultra-High Energy Cosmic Rays (UHECRs) is full of puzzling mysteries. The present state of the field is first outlined, as well as the contribution and prospects brought in by the Pierre Auger Observatory. The latter actually provided physicists with several key results: the measurement of the energy spectrum above a few EeV and the high-energy cutoff at a high significance level, the measurement of composition-sensitive variables that indicate the UHECRs are getting heavier with energy (though we can not rule out that it might be due to a significant modification of the hadronic physics around 100 TeV scale), and the measurement of a weak anisotropy signal except in a small region of the sky where an excess of events is observed, centered on an important source that might not being involved in this excess, Centaurus A. The second part of the thesis deals with UHECRs propagation in the extra-galactic medium and originating from their source. We study the implications of the composition at the sources and the acceleration parameters on the shape of propagated spectra at the Earth. We demonstrate the feasibility of an astrophysical model, the so-called low-Emax scenario, that fits both the spectrum and composition. A numerical code embedding protons and nuclei propagation, including magnetic fields, is also detailed in this section. In the fourth part, we present an independent study of the constraints brought in by the angular data of Auger on the effective density of UHECRs sources and the typical magnetic deflections they undergo. A percolation tool used to perform a direct data analysis (isotropy test) and demonstrating the weak anisotropy signal, is also presented. A whole part of the thesis is dedicated to a critical secondary particle: the photon. We discuss its extra-galactic propagation and its related numerical tool that was entirely developed during the thesis and incorporated in the existing proton/nuclei code. This leads to a global

  11. Energy increase of laser driven proton beams driven by ultra high intensity lasers and characterization of proton beams accelerated by ultra short laser pulses

    OpenAIRE

    Buffechoux, Sébastien

    2011-01-01

    Technological improvements since the 1980s have allowed for important developments in the field of high power lasers, thus paving the way for relativistic laser-matter interactions. With laser intensities higher than 1.1018 W.cm-2, the scientific community could explore a new physics, full of promising applications. Historically, laser–plasma interaction research initially aimed at exploring fusion by inertial confinement, but, with the breakthrough of ultra-high power lasers, the scope of re...

  12. 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)

  13. Design of Ultra High Performance Fiber Reinforced Concrete Shells

    DEFF Research Database (Denmark)

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

    2013-01-01

    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 Performan...

  14. 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.

  15. Ultra-High-Field MR Neuroimaging

    OpenAIRE

    Balchandani, P.; Naidich, T P

    2014-01-01

    At ultra-high magnetic fields, such as 7T, MR imaging can noninvasively visualize the brain in unprecedented detail and through enhanced contrast mechanisms. The increased SNR and enhanced contrast available at 7T enable higher resolution anatomic and vascular imaging. Greater spectral separation improves detection and characterization of metabolites in spectroscopic imaging. Enhanced blood oxygen level–dependent contrast affords higher resolution functional MR imaging. Ultra-high-field MR im...

  16. 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...

  17. 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)

  18. 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)

  19. Radiation pressure acceleration: The factors limiting maximum attainable ion energy

    Science.gov (United States)

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

    2016-05-01

    Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, 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 transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum ion energy.

  20. System for ultra high vacuum made of aluminum alloys

    International Nuclear Information System (INIS)

    We have developed the system for ultra high vacuum made of aluminum alloys for proton and electron synchrotron. This is the first system for ultra high vacuum in which bakable metal seal flange and small diametral bellows of aluminum alloys have been put to practical use. The system consists of the flange protected by a CrN thin film and made of 2219-T87 alloy, the chamber made of 6063-T6 alloy, the aluminum metal gasket of Helico Flex and the bellows made of 5052 alloy. As a result of experiments at the National Laboratory for High Energy Physics (KEK), it had been confirmed that this system shows the special qualities of ultra high vacuum operation, resistance to hard radiation and baking and cooling operations. Up to now, this system has been widely used for the beam lines of the booster synchrotron utilization facility, K1, K2, linac, PI 1 and EP2-B extension of the KEK proton synchrotron. We investigate that this system is applicable to nuclear energy utilization facility and general vacuum apparatus. (author)

  1. An ultra high frequency wideband filter

    OpenAIRE

    Pan, V.M.; Tarasov, V. F.; Futimsky, S. I.

    2008-01-01

    An ultra high frequency wideband filter was developed and fabricated. High-temperature superconductive film, sputtered in a sapphire substrate, was used as a resonator material. Loss in the filter pass band is 0.7 dB, the filter pass band is 165 MHz, its central frequency is 1877 MHz. The filter topology and amplitude-frequency responses are given.

  2. On scaling breakdown and the ways of modification of the elementary act model in the range of ultra-high energy

    International Nuclear Information System (INIS)

    Breaking of scale invariance of hadron interactions in the ultrahigh energy range has been considered. Presented are the results of calculations of the number of muons with the energy above 10 GeV with the number of electrons Nsub(e)=103-107 and of the number of hadrons with the energy above 1 TeV with the number of electrons Nsub(e)=105-107 in extensive air showers (EAS). The experimental data on the muon and hadron components of EAS have been shown to contradict the scale invariance model in an assumption that EAS are produced by primary protons

  3. Development of TUS pinhole cameras for observing transient luminous events from space and establishing role of those events as a background for ultra-high-energy cosmic-ray measurements

    Science.gov (United States)

    Kim, Ji Eun; Lee, Jik; Park, A. H.; Park, I. H.; Garipov, G. K.; Khrenov, B. A.; Klimov, P. A.; Panasyuk, M. I.

    2014-03-01

    The TUS (tracking ultraviolet setup) experiment is intended for the observation from space of ultraviolet (UV) fluorescence induced both by ultra-high-energy cosmic rays (UHECRs) with energies above 5 × 1019 eV and by transient luminous events (TLEs) occurring in the upper atmosphere. These two types of events are very different in terms of duration, lateral shape, and intensity; thus, each behaves as a background for the other. The TUS is equipped with two conventional pinhole cameras as auxiliary instrumentation to detect and efficiently distinguish TLEs from UHECRs. Each pinhole camera contains a MAPMT (multi-anode photo-multiplier tube) and its associated analog and digital electronics. The R11265-03-M64 MAPMT has been custom-made for space applications by Hamamatsu Photonics, particularly for the future EUSO (Extreme Universe Space Observatory) UHECR space mission. Thus, the TUS pinhole system will be the test bench for the deployment in space of a large number, ˜5000, of MAPMTs. In this study, we present the design and fabrication of the pinhole cameras, and we estimate the detectability of TLEs with respect to atmospheric light background.

  4. Microstructure of X210Cr12 steel after the forming in semi-solid state visualized by very low energy SEM in ultra high vacuum

    Czech Academy of Sciences Publication Activity Database

    Mikmeková, Šárka; Mašek, B.; Jirková, H.; Aišman, D.; Müllerová, Ilona; Frank, Luděk

    2013-01-01

    Roč. 275, 15 June (2013), s. 403-408. ISSN 0169-4332 R&D Projects: GA ČR GAP108/11/2270 Institutional support: RVO:68081731 Keywords : Very low energy SEM * Crystallographic contrast * Strain mapping * Semi-solid state processing Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.538, year: 2013

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

    International Nuclear Information System (INIS)

    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 1015 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.)

  6. 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.)

  7. Search for Point Sources of Ultra-High Energy Cosmic Rays Above 40 EeV Using a Maximum Likelihood Ratio Test

    CERN Document Server

    Farrar, G R; Abu-Zayyad, T; Amann, J F; Archbold, G; Atkins, R; Bellido, J A; Belov, K; Belz, J W; Ben-Zvi, S Y; Bergman, D R; Boyer, J H; Burt, G W; Cao, Z; Clay, R W; Connolly, B M; Dawson, B R; Deng, W; Fedorova, Y; Findlay, J; Finley, C B; Hanlon, W F; Hoffman, C M; Holzscheiter, M H; Hughes, G A; Jui, C C H; Kim, K; Kirn, M A; Knapp, B C; Loh, E C; Maestas, M M; Manago, N; Mannel, E J; Marek, L J; Martens, K; Matthews, J A J; Matthews, J N; O'Neill, A; Painter, C A; Perera, L P; Reil, K; Riehle, R; Roberts, M D; Sasaki, M; Schnetzer, S R; Seman, M; Simpson, K M; Sinnis, G; Smith, J D; Snow, R; Sokolsky, P; Song, C; Springer, R W; Stokes, B T; Thomas, J R; Thomas, S B; Thomson, G B; Tupa, D; Westerhoff, S; Wiencke, L R; Zech, A

    2004-01-01

    We present the results of a search for cosmic ray point sources at energies above 40 EeV in the combined data sets recorded by the AGASA and HiRes stereo experiments. The analysis is based on a maximum likelihood ratio test using the probability density function for each event rather than requiring an a priori choice of a fixed angular bin size. No statistically significant clustering of events consistent with a point source is found.

  8. Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger observatory with zenith angles up to 80°

    Czech Academy of Sciences Publication Activity Database

    Aab, A.; Abreu, P.; Aglietta, M.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Mandát, Dušan; Nečesal, Petr; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr; Vícha, Jakub

    2015-01-01

    Roč. 802, č. 2 (2015), s. 111. ISSN 0004-637X R&D Projects: GA MŠk(CZ) LG13007; GA MŠk(CZ) 7AMB14AR005; GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : astroparticle physics * cosmic rays Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.993, year: 2014

  9. Characteristics of geomagnetic cascading of ultra-high energy photons at the southern and northern sites of the Pierre Auger Observatory

    OpenAIRE

    Homola, P.; Risse, M.; Engel, R.; Gora, D.; Pekala, J.; Wilczynska, B.; Wilczynski, H.

    2006-01-01

    Cosmic-ray photons above 10^19 eV can convert in the geomagnetic field and initiate a preshower, i.e. a particle cascade before entering the atmosphere. We compare the preshower characteristics at the southern and northern sites of the Pierre Auger Observatory. In addition to a shift of the preshower patterns on the sky due to the different pointing of the local magnetic field vectors, the fact that the northern Auger site is closer to the geomagnetic pole results in a different energy depend...

  10. Is the ultra-high energy cosmic-ray excess observed by the telescope array correlated with IceCube neutrinos?

    International Nuclear Information System (INIS)

    The Telescope Array (TA) has observed a statistically significant excess in cosmic rays with energies above 57 EeV in a region of approximately 1150 deg2 centered on coordinates R.A. = 146.7, decl. = 43.2. We note that the location of this excess correlates with 2 of the 28 extraterrestrial neutrinos recently observed by IceCube. The overlap between the two IceCube neutrinos and the TA excess is statistically significant at the 2σ level. Furthermore, the spectrum and intensity of the IceCube neutrinos is consistent with a single source which would also produce the TA excess. Finally, we discuss possible source classes with the correct characteristics to explain the cosmic-ray and neutrino fluxes with a single source.

  11. 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.

  12. Detection of ultra-high-energy cosmic radiation at the Pierre Auger Observatory, theoretical study of its propagation through extragalactic space

    International Nuclear Information System (INIS)

    The Pierre Auger observatory's main aim is to observe the ultra-energetic cosmic ray spectrum with high statistics. Indeed, the spectrum around 1020 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)

  13. Ultra-high frequency magnetic resonance imaging

    OpenAIRE

    Magill, Arthur W.

    2007-01-01

    This thesis addresses the problem of radiofrequency probe design for Ultra High Frequency Magnetic Resonance Imaging (7T). The signal-to-noise ratio available in Magnetic Resonance Imaging (MRI) is determined by the static magnetic field strength, causing a continued drive toward higher fields to enable faster image acquisition at finer spatial resolution. The resonant frequency increases linearly with static field strength. At 7T the proton resonant frequency is 300MHz, with a wavelength...

  14. Joining of ultra-high temperature ceramics

    OpenAIRE

    Silvestroni, Laura; Sciti, Diletta; Esposito, Laura; Glaeser, Andreas

    2012-01-01

    In the last decade, ultra-high temperature ceramics raised renewed interest after the first studies in the 60's. Thanks to their high melting point, superior to any group of materials, and to their set of interesting physical and engineering properties, they find application in aerospace industry, propulsion field, as cladding materials in generation IV nuclear reactors and solar absorbers in novel HT CSP systems. Recent efforts were devoted to the achievement of high strength and toughness m...

  15. 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...

  16. 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.

  17. Ultra-high density diffraction grating

    Science.gov (United States)

    Padmore, Howard A.; Voronov, Dmytro L.; Cambie, Rossana; Yashchuk, Valeriy V.; Gullikson, Eric M.

    2012-12-11

    A diffraction grating structure having ultra-high density of grooves comprises an echellette substrate having periodically repeating recessed features, and a multi-layer stack of materials disposed on the echellette substrate. The surface of the diffraction grating is planarized, such that layers of the multi-layer stack form a plurality of lines disposed on the planarized surface of the structure in a periodical fashion, wherein lines having a first property alternate with lines having a dissimilar property on the surface of the substrate. For example, in one embodiment, lines comprising high-Z and low-Z materials alternate on the planarized surface providing a structure that is suitable as a diffraction grating for EUV and soft X-rays. In some embodiments, line density of between about 10,000 lines/mm to about 100,000 lines/mm is provided.

  18. Multilayer ultra-high-temperature ceramic coatings

    Science.gov (United States)

    Loehman, Ronald E.; Corral, Erica L.

    2012-03-20

    A coated carbon-carbon composite material with multiple ceramic layers to provide oxidation protection from ultra-high-temperatures, where if the carbon-carbon composite material is uninhibited with B.sub.4C particles, then the first layer on the composite material is selected from ZrB.sub.2 and HfB.sub.2, onto which is coated a layer of SiC coated and if the carbon-carbon composite material is inhibited with B.sub.4C particles, then protection can be achieved with a layer of SiC and a layer of either ZrB.sub.2 and HfB.sub.2 in any order.

  19. New small gauge for ultra high vacuum

    International Nuclear Information System (INIS)

    Recently, for large accelerators and storage rings, ultra high vacuum of about 10-11 Torr, and 10-12 Torr for specific cases have been required. In the vacuum measurement for these accelerators, it is estimated that the maintenance of its accuracy is very difficult because of (1) causing error by the incidence of secondary charged particles into vacuum gauges, and (2) the presence of intense noise sources such as electromagnetic interference in the way of output signal transmission and induction by commercial AC power lines. As a solution for (1), the method to prevent the intrusion of charged particles by applying appropriate potential to the double meshes surrounding gauges is considered. However, this method requires to make gauge size small, and necessitates the development of gauges whose K/lambda is larger than 5/Torr-cm, where lambda is the cube root of anode volume in cm, and K is the sensitivity of extractor type ionization gauges in Torr-1. As a solution for (2), the method is considered, in which a modulator electrode is added to a gauge, and an AC amplifier is employed by modulating the ion current. Especially the lock-in detection is effective for improving the S/N ratio. In this paper, the construction and the experimental results of the gauge to which those measures were applied are described. The experimental results include fundamental characteristics, the permeating rate of ions and modulation characteristic. Employing a hemispherical anode in the ion source, the production of the gauges smaller than 1/2 in size as compared with conventional extractor gauges is possible without decreasing the sensitivity. (Wakatsuki, Y.)

  20. Ultra high performance concrete dematerialization study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-03-01

    Concrete is the most widely used building material in the world and its use is expected to grow. It is well recognized that the production of portland cement results in the release of large amounts of carbon dioxide, a greenhouse gas (GHG). The main challenge facing the industry is to produce concrete in an environmentally sustainable manner. Reclaimed industrial by-proudcts such as fly ash, silica fume and slag can reduce the amount of portland cement needed to make concrete, thereby reducing the amount of GHGs released to the atmosphere. The use of these supplementary cementing materials (SCM) can also enhance the long-term strength and durability of concrete. The intention of the EcoSmart{sup TM} Concrete Project is to develop sustainable concrete through innovation in supply, design and construction. In particular, the project focuses on finding a way to minimize the GHG signature of concrete by maximizing the replacement of portland cement in the concrete mix with SCM while improving the cost, performance and constructability. This paper describes the use of Ductal{sup R} Ultra High Performance Concrete (UHPC) for ramps in a condominium. It examined the relationship between the selection of UHPC and the overall environmental performance, cost, constructability maintenance and operational efficiency as it relates to the EcoSmart Program. The advantages and challenges of using UHPC were outlined. In addition to its very high strength, UHPC has been shown to have very good potential for GHG emission reduction due to the reduced material requirements, reduced transport costs and increased SCM content. refs., tabs., figs.

  1. 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.)

  2. Recipe for attaining optimal energy resolution in inorganic scintillators

    International Nuclear Information System (INIS)

    Using an approximate form of the density of excitation created within the track initiated by an incident γ - 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.)

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

    Science.gov (United States)

    Porras, A.; Tellez, J.; Casas-Rodriguez, J. P.

    2012-08-01

    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.

  4. 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.

  5. Ultra-high-field magnetic resonance: Why and when?

    OpenAIRE

    Moser, Ewald

    2010-01-01

    This paper briefly summarizes the development of magnetic resonance imaging and spectroscopy in medicine. Aspects of magnetic resonancephysics and -technology relevant at ultra-high magnetic fields as well as current limitations are highlighted. Based on the first promising studies, potential clinical applications at 7 Tesla are suggested. Other aims are to stimulate awareness of the potential of ultra-high field magnetic resonance and to stimulate active participation in much needed basic or...

  6. Possible Signature of Low Scale Gravity in Ultra High Enegry Cosmic Rays

    OpenAIRE

    R. V. Konoplich; Rubin, S. G.

    2000-01-01

    We show that the existence of low scale gravity at TeV scale could lead to a direct production of photons with energies above 10^22 eV due to annihilation of ultra high energy neutrinos on relic massive neutrinos of the galactic halo. Air showers initialized in the terrestrial atmosphere by these ultra energetic photons could be collected in near future by the new generation of cosmic ray experiments.

  7. 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.

  8. 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.

  9. Surface modification of ion implanted ultra high molecular weight polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Chen Jingsheng; Zhu Fuying; Pan Haochang; Cao Jianqing; Zhu Dezhang E-mail: dezhang_zhu@hotmail.com; Xu Hongjie; Cai Qing; Shen Jingen; Chen Lihua; He Zhengrui

    2000-06-02

    The surface modification has been studied for the ultra high molecular weight polyethylene (UHMWPE) implanted by 80 keV N{sub 2}{sup +}, C{sub 3}H{sub 8}{sup +} (40 keV N{sup +}, 22 keV C{sup +}) with fluences ranging from 1x10{sup 14} to 5x10{sup 15} ions/cm{sup 2}. Elastic recoil detection (ERD) and X-ray photoelectron spectroscopy (XPS) have been employed to characterize the modified surface of the samples. ERD results show that the high energy edge of ERD spectra shifts in the lower energy direction with the increase of implantation fluency, indicating that a hydrogen deficient surface layer is formed after implantation. XPS result shows that injected nitrogen atoms assist in crosslinking by forming chemical bonds with the polymer chains. KyowA's DF-PM reciprocating tester has been used to measure the wear property before and after implantation. The results show that the wear-resistance of samples after N{sub 2}{sup +}, C{sub 3}H{sub 8}{sup +} implantation has been improved by 68 and 47.5 times, respectively. Some interpretations are given to explain the observed phenomena.

  10. Fiscal 1997 report on the development of an energy use rationalization ultra-high tech liquid crystal technology. Project of development/promotion of ultra-high tech electronic technology / technology of design/control/analysis of new functional electronic materials; 1997 nendo kenkyu seika hokokusho energy shiyo gorika chosentan ekisho gijutsu kaihatsu. Chosentan denshi gijutsu kaihatsu sokushin jigyo / shinkino denshi zairyo sekkei seigyo bunseki gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    A research was conducted with the aim of developing an ultra-low power consuming type information display which supports the next next generation informatizing society. As to the function combined type fine structure formation technology, a formation technology of fine structure supporting multi-layer pixel by organic polymer materials was established to confirm a possibility of adopting it to high functional liquid crystal display. Concerning the high functional fine structure formation technology, a study was proceeded with on holographic PDLC which is an interference reflection coloring method. In relation to the low temperature film formation technology of ferroelectric thin films, a film formation device was introduced to obtain basic data, and at the same time a possibility was studied of improving film characteristics by laser annealing conducted after the film formation. Moreover, concerning the new functional material technology, studies were made of optical interference/high light-scattering control materials, light alignment elements, ultra-high purity/ultra-reliable optical materials, ultra-anisotropy optical materials, etc. About the light reflection characteristics control technology, studied were new liquid crystal molucular orientaion control technology, multi-dimensional anisotropy structure formation technology, etc. 100 refs., 273 figs., 58 tabs.

  11. 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.

  12. Diffusion of Vitamin E in Ultra-high Molecular Weight Polyethylene

    OpenAIRE

    Oral, Ebru; Wannomae, Keith K.; Rowell, Shannon L.; Muratoglu, Orhun K.

    2007-01-01

    Vitamin E-doped, radiation cross-linked ultra-high molecular weight polyethylene (UHMWPE) is developed as an alternate oxidation and wear resistant bearing surface in joint arthroplasty. We analyzed the diffusion behavior of vitamin E through UHMWPE and predicted penetration depth following doping with vitamin E and subsequent homogenization in inert gas used to penetrate implant components with vitamin E. Cross-linked UHMWPE (65- and 100-kGy irradiation) had higher activation energy and lowe...

  13. High thermal conductivity ultra-high molecular weight polyethylene (UHMWPE) films

    OpenAIRE

    Ghasemi, Hadi; Thoppey, Nagarajan; Huang, Xiaopeng; Loomis III, Robert James; Li, Xiaobo; Tong, Jonathan K.; Wang, Jianjian; Chen, Gang

    2014-01-01

    Recently, high thermally conductive polymers have emerged as low cost and energy efficient alternatives to traditional use of metals in heat transfer applications. Here, we present development of ultra-high molecular weight polyethylene (UHMWPE) thin films with high thermal conductivity. The fabrication platform is based on a sol-gel process followed by mechanical drawing. After gel formation and partial drying, UHMWPE films are mechanically stretched at elevated temperatures, resulting in ma...

  14. 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.

  15. Attained energy densities and neutral pion spectra in nucleus-nucleus collisions at 200 GeV/nucleon

    International Nuclear Information System (INIS)

    The main goal of the CERN heavy-ion experiments is the search for an indication that the predicted state of deconfined quarks and gluons, the quark-gluon plasma (QGP), has been produced. The quantity most crucial to the probability of QGP formation is the thermalized energy density attained during the heavy-ion reaction. The amount of energy radiated transverse to the beam direction is the experimental quantity which is believed to be a measure of the amount of energy deposition in the reaction, and hence to reflect the energy density attained. In this presentation we consider the systematics of transverse energy production at CERN SPS energies, and we use the results to make estimates, under various assumptions, of attained energy densities. 18 refs., 2 figs

  16. Shock characterization of an ultra-high strength concrete

    Science.gov (United States)

    Erzar, B.; Pontiroli, C.; Buzaud, E.

    2016-04-01

    Nowadays, the design of protective structures may imply ultra-high performance concretes. These materials present a compressive strength 5 times higher than standard concretes. However, few reliable data on the shock response of such materials are available in the literature. Thus, a characterization of an ultra-high strength concrete has been conducted by means of hydrostatic and triaxial tests in the quasi-static regime, and plate impact experiments for shock response. Data have been gathered up to 6 GPa and a simple modelling approach has been applied to get a reliable representation of the shock compression of this concrete.

  17. Rapid and Deep Proteomes by Faster Sequencing on a Benchtop Quadrupole Ultra-High-Field Orbitrap Mass Spectrometer

    DEFF Research Database (Denmark)

    Kelstrup, Christian D; Jersie-Christensen, Rosa R; Batth, Tanveer Singh;

    2014-01-01

    Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage is...... evaluated by four different acquisition methods and benchmarked across three generations of Q Exactive instruments (ProteomeXchange dataset PXD001305). We find the ultra-high-field Orbitrap mass analyzer capable of attaining a sequencing speed above 20 Hz and it routinely exceeds 10 peptide spectrum matches......-shot phosphoproteomics, where we identify 7600 unique HeLa phospho-peptides in one gradient hour and find the quality of fragmentation spectra to be more important than quantity for accurate site assignment....

  18. Ultra-high density aligned Carbon-nanotube with controled nano-morphology for supercapacitors

    Science.gov (United States)

    Ghaffari, Mehdi; Zhao, Ran; Liu, Yang; Zhou, Yue; Cheng, Jiping; Guzman de Villoria, Roberto; Wardle, B. L.; Zhang, Q. M.

    2012-02-01

    Recent advances in fabricating controlled-morphology vertically aligned carbon nanotubes (VA-CNTs) with ultrahigh volume fractioncreate unique opportunities for developing unconventional supercapacitors with ultra-high energy density, power density, and long charge/discharge cycle life.Continuous paths through inter-VA-CNT channels allow fast ion transport, and high electrical conduction of the aligned CNTs in the composite electrodes lead to fast discharge speed. We investigate the charge-discharge characteristics of VA-CNTs with >20 vol% of CNT and ionic liquids as electrolytes. By employing both the electric and electromechanical spectroscopes, as well as nanostructured materials characterization, the ion transport and storage behaviors in porous electrodes are studied. The results suggest pathways for optimizing the electrode morphology in supercapacitorsusing ultra-high volume fraction VA-CNTs to further enhance performance.

  19. Environmental assessment of Ultra-High Pressure Homogenisation for milk and fresh cheese production

    DEFF Research Database (Denmark)

    Valsasina, Lucia; Pizzol, Massimo; Smetana, Sergiy;

    2015-01-01

    This study analyses the application of Ultra High Pressure Homogenisation (UHPH), an innovative technology for food sterilisation that relies on pressure up to 400MPa, for the treatment of cow milk. The technology is forseen to provide equal or higher quality products compared to Ultra High...... Temperature (UHT) treatment and, at the same time, to lower energy consumptions through the combination of pasteurisation and homogenisation in a single process. Furthermore, the use of UHPH treated milk for the production of fresh cheese has been proven to increase shelf life days and increase yield This...... study provides an LCA of UHPH and UHT processing of milk and fresh cheese production from processing to end-of-life....

  20. A geometry force field which converts low-resolution X-ray models to structures with properties found at ultra high resolution

    OpenAIRE

    McMartin, Colin

    2011-01-01

    A geometry optimization force field was developed using ultra high-resolution structures and tested using high- and low-resolution X-ray structures. Protein and small molecule X-ray data was used. When applied to ultra high-resolution structures the force field conserves the internal geometry and local strain energy. When applied to low-resolution structures there is a small change in geometry accompanied by a large drop in local strain energy. Although optimization causes only small structur...

  1. 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...

  2. Enhancement of maximum attainable ion energy in the radiation pressure acceleration regime using a guiding structure

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-13

    Radiation Pressure Acceleration is a highly efficient mechanism of laser driven ion acceleration, with the laser energy almost totally transferrable to the ions in the relativistic regime. There is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. In the case of a tightly focused laser pulses, which are utilized to get the highest intensity, another factor limiting the maximum ion energy comes into play, the transverse expansion of the target. Transverse expansion makes the target transparent for radiation, thus reducing the effectiveness of acceleration. Utilization of an external guiding structure for the accelerating laser pulse may provide a way of compensating for the group velocity and transverse expansion effects.

  3. 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)

  4. 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....

  5. Hyphenated ultra high-performance liquid chromatography–Nano Quantity

    Czech Academy of Sciences Publication Activity Database

    Olšovská, Jana; Kameník, Zdeněk; Cajthaml, Tomáš

    2009-01-01

    Roč. 1216, č. 30 (2009), s. 5774-5778. ISSN 0021-9673 R&D Projects: GA MŠk 1M06011 Institutional research plan: CEZ:AV0Z50200510 Keywords : macrolides * uv detection * ultra high-perfonmance liquid chromatography Subject RIV: EE - Microbiology, Virology Impact factor: 4.101, year: 2009

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

    International Nuclear Information System (INIS)

    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 0.74). 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

  7. Mechanical design considerations for a precision, ultra high vacuum manipulator

    International Nuclear Information System (INIS)

    The design of mechanisms for use in an ultra high vacuum (UHV) environment presents special problems. The additional design constraints due to requirements of fusion machines further limit the engineer's flexibility in the design process. Requirements for precise control of position and large range of motion present a further challenge. With the advent of tritium in fusion devices, reliability and ease of remote maintenance are matters of paramount importance. The design of the TFTR impurity injector illustrates some of these problems and their solutions. The effects of different impurities on a plasma can be studied by injecting small amounts of an impurity into the plasma and using other diagnostic instruments to record the results. A thin layer of an impurity is coated on a glass slide which is approximately two inches square. A high energy laser beam is focused onto a small spot on the slide. When the laser is pulsed, the impurity evaporates from the target and drifts into the plasma. The TFTR impurity injector will hold sixteen coated slides inside a vacuum. The required positioning accuracy is one tenth of a millimeter. Simultaneous requirements for a large range of motion and high positioning accuracy present unusual design problems. Requirements for radiation resistance and remote maintainability have an impact on the design. In this paper, the trade-offs between different design methodologies are discussed in detail. Various design concepts for the TFTR impurity injector are analyzed from the standpoints of functionality, reliability, and cost; the results are generalized so that they will be of use to other designers

  8. Recuperative system for high and ultra-high temperature flue gases. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Reitz, J.G.; Coeling, K.J.; Thekdi, A.C.

    1979-01-31

    Advanced recuperative system technology for high and ultra-high temperature flue gases was investigated. Several high temperature recuperator system and component concepts were evolved and studied for the purpose of finding the schemes and designs that attain maximum fuel savings. The most promising concepts for industrial application were pre-engineered further to devise designs for adaptation to existing steel mills. The principal effort was aimed at steel soaking pit applications. The concept which provides the highest air preheat temperatures and the largest fuel savings for soaking pit application utilizing basic state-of-the-art technology is a low air pressure ceramic recuperator operated in conjunction with a higher air pressure metallic recuperator. This concept has the additional advantage that higher air pressures can be attained at the burner than can be attained with an all ceramic recuperator. These higher air pressures are required for high momentum, high efficiency burner performance, resulting in improved productivity and additional fuel savings. The technical feasibility of applying this high temperature recuperation system to existing soaking pits was established.

  9. Modified master curve of ultra high strength steel

    International Nuclear Information System (INIS)

    The classical Master Curve approach covers the ferritic steels with a yield strength range of 275 MPa–825 MPa. The ultra high strength steel S960 QC is out of this range, and it does not follow the formula determined in the ASTM E1921-05 Standard. In this paper, the results of the research program are presented, and a new Master-like curve is derived. The new curve preserves the basic features of the classical Master Curve; it simply widens the family of Master Curves. - Highlights: ► Fracture toughness of the S960 QC steel was analyzed at the ductile–cleavage transition region. ► The S960 QC steel does not follow the classical Master Curve equation. ► No thickness effect on fracture toughness was observed in the thicknesses range tested. ► New Master Curve for the ultra high strength steel was determined.

  10. 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...... that silicon can indeed be used to control Tbit/s serial data signals [2], perform 640 Gbit/s wavelength conversion [3] 640 Gbit/s serial-to-parallel conversion [4], 160 Gbit/s packet switching as well as all-optical regeneration [5]. We will also discuss the performance limitations of crystalline silicon...

  11. 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...

  12. 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.

  13. Reduction of hydrogen embrittlement on Electrogalvanized Ultra High Strength Steels

    OpenAIRE

    Haglund, Adam

    2014-01-01

    Ultra-high strength steels is known to be susceptible for hydrogen embrittlement at very low concentrations of hydrogen. In this thesis three methods to prevent or reduce the hydrogen embrittlement in martensitic steel, with tensile strength of 1500 MPa, were studied. First, a barrier layer of aluminium designed to prevent hydrogen to enter the steel, which were deposited by vacuum evaporation. Second, a decarburization process of the steels surface designed to mitigate the induced stresses f...

  14. Hydrogen re-embrittlement susceptibility of ultra high strength steels

    OpenAIRE

    Figueroa-Gordon, Douglas J.

    2005-01-01

    300M ultra high strength steel has been widely used for over forty years as a structural material in aerospace applications where a high strength is required. These parts are generally protected from corrosion by electroplated cadmium sacrificial coatings. However, there are concerns over this coating material due to its high toxicity and alternative coatings including Zinc-14%Nickel and SermeTel®1140/962 have been considered. It is known that applying electrodeposited coati...

  15. Ultra High Molecular Weight Polyethylene: Mechanics, Morphology, and Clinical Behavior

    OpenAIRE

    Sobieraj, MC; Rimnac, CM

    2008-01-01

    Ultra high molecular weight polyethylene (UHMWPE) is a semicrystalline polymer that has been used for over four decades as a bearing surface in total joint replacements. The mechanical properties and wear properties of UHMWPE are of interest with respect to the in vivo performance of UHMWPE joint replacement components. The mechanical properties of the polymer are dependent on both its crystalline and amorphous phases. Altering either phase (i.e., changing overall crystallinity, crystalline m...

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

    OpenAIRE

    Casas-Rodriguez J.P.; Tellez J.; Porras A.

    2012-01-01

    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 interlami...

  17. Ultra-high-field magnets for future hadron colliders

    International Nuclear Information System (INIS)

    Several new concepts in magnetic design and coil fabrication are being incorporated into designs for ultra-high field collider magnets: a 16 Tesla block-coil dual dipole, also using Nb3Sn cable, featuring simple pancake coil construction and face-loaded prestress geometry; a 330 T/m block-coil quadrupole; and a ∼ 20 Tesla pipe-geometry dual dipole, using A15 or BSCCO tape. Field design and fabrication issues are discussed for each magnet

  18. The ultra high vacuum system of the AGS Booster

    Energy Technology Data Exchange (ETDEWEB)

    Hseuh, H.C.; Sadinsky, S.; Savino, J.; Schnitzenbaumer, P.; Sattel, P.; Van Zwienen, W.; Xiuhua, Cui

    1989-01-01

    The AGS Booster currently under construction at Brookhaven is a synchrotron for the acceleration of both protons and heavy ions. The design pressure of 3 /times/ 10/sup /minus/11/ Torr is required to minimize beam loss of the partially stripped heavy ions. This paper described the design and processing of the ultra high vacuum system, and the performance of the prototype vacuum half cells. 9 refs., 4 figs.

  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 strain rate behavior of FCC nanostructures

    OpenAIRE

    Crum, Ryan Scott

    2016-01-01

    This work addresses the influence of ultra-high strain rates loading observed in our world today via ballistics, explosions and astrophysical collisions on well-defined metal structures. There is a plentiful amount of research examining metals at a macroscopic level that are subjected to ballistics and explosions but observing the microstructure is difficult as those procedures are fairly destructive testing mechanisms. Therefore, to understand the true mechanisms that occur in these loading ...

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

    OpenAIRE

    Shashwat V. Joshi; Amit Kachhadiya; Prof. Minal S. Dani; Prof.Indravadan B Dave

    2014-01-01

    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 tec...

  2. Challenges in Resistance Welding of Ultra High Strength Steels

    OpenAIRE

    Tolf, Erik

    2015-01-01

    Increasing the use of Ultra High Strength Steels (UHSS) in vehicle bodystructures is important for reducing weight and cutting CO2 emissions. This thesis investigates challenges in resistance welding that can be a barrier to implementing UHSS as a replacement for low strength steels in vehicle structures. Empirical research has been performed to offer new approaches for improved joint strength and to increase knowledge on cracking mechanisms in resistance projection welding and resistance spo...

  3. 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

  4. 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.

  5. Ztek`s ultra high efficiency fuel cell/gas turbine combination

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, M.; Nathanson, D. [Ztek Corp., Waltham, MA (United States)

    1995-10-19

    Ztek is proceeding on development of an ultra-high efficiency hybrid system of its Planar SOFC with a gas turbine, realizing shared cost and performance benefits. The gas turbine as the Balance-of-Plant was a logical selection from a fuel cell system perspective because of (1) the high-power-density energy conversion of gas turbines; (2) the unique compatibility of the Ztek Planar SOFC with gas turbines, and (3) the availability of low-cost commercial gas turbine systems. A Tennessee Valley Authority/Ztek program is ongoing, which addresses operation of the advanced Planar SOFC stacks and design scale-up for utility power generation applications.

  6. 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.

  7. Radio reconstruction of the mass of ultra-high cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Dorosti, Qader [Institut fuer Kernphysik (IKP), KIT (Germany)

    2015-07-01

    Detection of ultra-high energy cosmic rays can reveal the processes of the most violent sources in the Universe, which yet has to be determined. Interaction of cosmic rays with the Earth's atmosphere results in cascades of secondary particles, i.e. air showers. Many of such particles are electrons and positrons. The induced electrons and positrons interact with the geomagnetic field and induce radio emissions. Detection of air showers along with the detection of induced radio emissions can furnish a precise measurement of the direction, energy and mass of ultra-high energy cosmic rays. The Auger Engineering Radio Array consists of 124 radio stations measuring radio emission from air showers, in order to reconstruct the energy, direction and mass of cosmic rays. In this contribution, we present a method which employs a reduced hyperbolic model to describe the shape of radio wave front. We have investigated that the parameters of the reduced hyperbolic model are sensitive to the mass of cosmic rays. The obtained results are presented in this talk.

  8. Generation of Ultra-high Intensity Laser Pulses

    International Nuclear Information System (INIS)

    Mainly due to the method of chirped pulse amplification, laser intensities have grown remarkably during recent years. However, the attaining of very much higher powers is limited by the material properties of gratings. These limitations might be overcome through the use of plasma, which is an ideal medium for processing very high power and very high total energy. A plasma can be irradiated by a long pump laser pulse, carrying significant energy, which is then quickly depleted in the plasma by a short counterpropagating pulse. This counterpropagating wave effect has already been employed in Raman amplifiers using gases or plasmas at low laser power. Of particular interest here are the new effects which enter in high power regimes. These new effects can be employed so that one high-energy optical system can be used like a flashlamp in what amounts to pumping the plasma, and a second low-power optical system can be used to extract quickly the energy from the plasma and focus it precisely. The combined system can be very compact. Thus, focused intensities more than 1025 W/cm2 can be contemplated using existing optical elements. These intensities are several orders of magnitude higher than what is currently available through chirped pump amplifiers

  9. Generation of Ultra-high Intensity Laser Pulses

    Energy Technology Data Exchange (ETDEWEB)

    N.J. Fisch; V.M. Malkin

    2003-06-10

    Mainly due to the method of chirped pulse amplification, laser intensities have grown remarkably during recent years. However, the attaining of very much higher powers is limited by the material properties of gratings. These limitations might be overcome through the use of plasma, which is an ideal medium for processing very high power and very high total energy. A plasma can be irradiated by a long pump laser pulse, carrying significant energy, which is then quickly depleted in the plasma by a short counterpropagating pulse. This counterpropagating wave effect has already been employed in Raman amplifiers using gases or plasmas at low laser power. Of particular interest here are the new effects which enter in high power regimes. These new effects can be employed so that one high-energy optical system can be used like a flashlamp in what amounts to pumping the plasma, and a second low-power optical system can be used to extract quickly the energy from the plasma and focus it precisely. The combined system can be very compact. Thus, focused intensities more than 10{sup 25} W/cm{sup 2} can be contemplated using existing optical elements. These intensities are several orders of magnitude higher than what is currently available through chirped pump amplifiers.

  10. 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

  11. 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

  12. Fusion: ultra-high-speed and IR image sensors

    Science.gov (United States)

    Etoh, T. Goji; Dao, V. T. S.; Nguyen, Quang A.; Kimata, M.

    2015-08-01

    Most targets of ultra-high-speed video cameras operating at more than 1 Mfps, such as combustion, crack propagation, collision, plasma, spark discharge, an air bag at a car accident and a tire under a sudden brake, generate sudden heat. Researchers in these fields require tools to measure the high-speed motion and heat simultaneously. Ultra-high frame rate imaging is achieved by an in-situ storage image sensor. Each pixel of the sensor is equipped with multiple memory elements to record a series of image signals simultaneously at all pixels. Image signals stored in each pixel are read out after an image capturing operation. In 2002, we developed an in-situ storage image sensor operating at 1 Mfps 1). However, the fill factor of the sensor was only 15% due to a light shield covering the wide in-situ storage area. Therefore, in 2011, we developed a backside illuminated (BSI) in-situ storage image sensor to increase the sensitivity with 100% fill factor and a very high quantum efficiency 2). The sensor also achieved a much higher frame rate,16.7 Mfps, thanks to the wiring on the front side with more freedom 3). The BSI structure has another advantage that it has less difficulties in attaching an additional layer on the backside, such as scintillators. This paper proposes development of an ultra-high-speed IR image sensor in combination of advanced nano-technologies for IR imaging and the in-situ storage technology for ultra-highspeed imaging with discussion on issues in the integration.

  13. Ultra-high-Q tunable whispering-gallery-mode microresonator

    CERN Document Server

    Pöllinger, M; Warken, F; Rauschenbeutel, A

    2009-01-01

    Typical microresonators exhibit a large frequency spacing between resonances and a limited tunability. This impedes their use in a large class of applications which require a resonance of the microcavity to coincide with a predetermined frequency. Here, we experimentally overcome this limitation with highly prolate-shaped whispering-gallery-mode "bottle microresonators" fabricated from standard optical glass fibers. Our resonators combine an ultra-high quality factor of 360 million, a small mode volume, and near lossless fibre coupling, characteristic of whispering-gallery-mode resonators, with a simple and customizable mode structure enabling full tunability.

  14. 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 testbeds....... 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....

  15. 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.

  16. 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.

  17. Recent developments in ultra-high intensity laser plasma diagnostics at RRCAT

    International Nuclear Information System (INIS)

    The commercial availability of laser systems with petawatt power has rejuvenated the research in the field of ultra-high intensity laser plasma interaction, especially in the field of particle acceleration. Electron acceleration by the laser wake-field technique has been demonstrated with electron beams of energy above GeV. The diagnostics have to be developed in-house due to their stringent requirements. Laser Plasma Division, RRCAT, is involved in development of these diagnostics to carry out ultra-high intensity plasma interaction studies viz. electron, proton/ion acceleration, and neutron generation. They have demonstrated well collimated, quasi-mono-energetic electron beam of 50 MeV by laser wakefield acceleration technique, and proton beam up to 3 MeV in thin Al foil targets. Recently they have extended the electron acceleration technique to plasma plume produced by pre pulse laser solid target interaction, instead of the gas jet target. A well collimated, quasi-monoenergetic beam of 13 MeV has been demonstrated. They have also measured neutron flux of ∼104 neutrons in single shot, produced in the interaction of ultra-high intensity laser pulses with solid CD2 target by D-D fusion reaction. The present talk will provide details of various spatial and temporal plasma diagnostics developed for detection of x-rays and particles. These include : crystal, grating, and dispersionless spectrographs, Thomson parabola ion spectrograph, magnet based electron spectrograph, time of flight neutron detector, chirped laser pulse based time resolved optical diagnostics, x-ray bolometer, and optical and x-ray streak cameras

  18. An optimization of the FPGA/NIOS adaptive FIR filter using linear prediction to reduce narrow band RFI for the next generation ground-based ultra-high energy cosmic-ray experiment

    International Nuclear Information System (INIS)

    The electromagnetic part of an extensive air shower developing in the atmosphere provides significant information complementary to that obtained by water Cherenkov detectors which are predominantly sensitive to the muonic content of an air shower at ground. The emissions can be observed in the frequency band between 10 and 100 MHz. However, this frequency range is significantly contaminated by narrow-band RFI and other human-made distortions. The Auger Engineering Radio Array currently suppresses the RFI by multiple time-to-frequency domain conversions using an FFT procedure as well as by a set of manually chosen IIR notch filters in the time-domain. An alternative approach developed in this paper is an adaptive FIR filter based on linear prediction (LP). The coefficients for the linear predictor are dynamically refreshed and calculated in the virtual NIOS processor. The radio detector is an autonomous system installed on the Argentinean pampas and supplied from a solar panel. Powerful calculation capacity inside the FPGA is a factor. Power consumption versus the degree of effectiveness of the calculation inside the FPGA is a figure of merit to be minimized. Results show that the RFI contamination can be significantly suppressed by the LP FIR filter for 64 or less stages. -- Highlights: • We propose an adaptive method using linear prediction for periodic RFI suppression. • Requirements are the detection of short transient signals powered by solar panels. • The RFI is significantly suppressed by ∼70%, even in a very contaminated environment. • This method consumes less energy than the current method based on FFT used in AERA. • Distortion of the short transient signals is negligible

  19. An optimization of the FPGA/NIOS adaptive FIR filter using linear prediction to reduce narrow band RFI for the next generation ground-based ultra-high energy cosmic-ray experiment

    Energy Technology Data Exchange (ETDEWEB)

    Szadkowski, Zbigniew, E-mail: zszadkow@kfd2.phys.uni.lodz.pl [University of Lodz, Department of Physics and Applied Informatics (Poland); Fraenkel, E.D. [Kernfysisch Versneller Instituut of the University of Groningen, Groningen (Netherlands); Glas, Dariusz; Legumina, Remigiusz [University of Lodz, Department of Physics and Applied Informatics (Poland)

    2013-12-21

    The electromagnetic part of an extensive air shower developing in the atmosphere provides significant information complementary to that obtained by water Cherenkov detectors which are predominantly sensitive to the muonic content of an air shower at ground. The emissions can be observed in the frequency band between 10 and 100 MHz. However, this frequency range is significantly contaminated by narrow-band RFI and other human-made distortions. The Auger Engineering Radio Array currently suppresses the RFI by multiple time-to-frequency domain conversions using an FFT procedure as well as by a set of manually chosen IIR notch filters in the time-domain. An alternative approach developed in this paper is an adaptive FIR filter based on linear prediction (LP). The coefficients for the linear predictor are dynamically refreshed and calculated in the virtual NIOS processor. The radio detector is an autonomous system installed on the Argentinean pampas and supplied from a solar panel. Powerful calculation capacity inside the FPGA is a factor. Power consumption versus the degree of effectiveness of the calculation inside the FPGA is a figure of merit to be minimized. Results show that the RFI contamination can be significantly suppressed by the LP FIR filter for 64 or less stages. -- Highlights: • We propose an adaptive method using linear prediction for periodic RFI suppression. • Requirements are the detection of short transient signals powered by solar panels. • The RFI is significantly suppressed by ∼70%, even in a very contaminated environment. • This method consumes less energy than the current method based on FFT used in AERA. • Distortion of the short transient signals is negligible.

  20. Hydrogen utilization international clean energy system technology (WE-NET). Subtask 8. Research and development of hydrogen combustion turbines (development of ultra-high temperature materials); Suiso riyo kokusai clean energy system (WE-NET). Subtask 8. Suiso nensho turbine no kenkyu kaihatsu chokoon zairyo no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The paper described the result of the fiscal 1996 development of ultra-high temperature materials for parts of hydrogen combustion turbines, as part of the hydrogen utilization technology, which have excellent environmental protectivity and remarkably high efficiency. By the optimized solution heat treatment of monocrystal alloy developed in the previous fiscal year, obtained was strength property the same as the existing super alloys. As to FRC, pore size and strength property of SiC organic hybrid were made clear. ODS alloy cooling blades and heat insulation coating were studied, and YSZ was found to be most excellent as coating material. Concerning intermetallic compounds, the applicability to ultra-high temperatures up to 1700degC was not obtained. For improvement of heat resistance and environment resistance, adopted were highly compacting SiC matrix and BN coatings. Al2O3 was excellent in long-time stability. In the 1600degC steam corrosion test on multiplex structural materials with Al2O3 as surface material, chemical stability was confirmed. Three-dimensional woven fiber reinforced composite materials of C/C{center_dot}CMC were trially produced by changing the fiber orientation, and improvement in ultra-high temperature thermal shock resistance was confirmed. A study was made of spot observation of the specimen surface by laser microscope, and development was conducted of a temperature measuring method with no influence of radiant heat. 44 refs., 250 figs., 40 tabs.

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

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27338408

  2. 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.

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

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27338408

  4. Ultra-high pressure water jet: Baseline report

    International Nuclear Information System (INIS)

    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

  5. 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. PMID:26295438

  6. 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 conductive atomic force microscopy and it was observed that the leakage is associated with TiO2 nanoparticles embedded in the CRS polymer matrix. A new class of ultra high dielectric constant hybrids using nanoscale inorganic dielectrics dispersed in a high permittivity polymer suitable for energy management applications is reported. PMID:27040504

  7. New solid laser: Ceramic laser. From ultra stable laser to ultra high output laser

    International Nuclear Information System (INIS)

    An epoch-making solid laser is developed. It is ceramic laser, polycrystal, which is produced as same as glass and shows ultra high output. Ti3+:Al2O3 laser crystal and the CPA (chirped pulse amplification) technique realized new ultra high output lasers. Japan has developed various kinds of ceramic lasers, from 10-2 to 67 x 103 w average output, since 1995. These ceramic lasers were studied by gravitational radiation astronomy. The scattering coefficient of ceramic laser is smaller than single crystals. The new fast ignition method is proposed by Institute of Laser Engineering of Osaka University, Japan. Ultra-intense short pulse laser can inject the required energy to the high-density imploded core plasma within the core disassembling time. Ti3+:Al2O3 crystal for laser, ceramic YAG of large caliber for 100 kW, transparent laser ceramic from nano-crystals, crystal grain and boundary layer between grains, the scattering coefficient of single crystal and ceramic, and the derived release cross section of Yb:YAG ceramic are described. (S.Y.)

  8. Magnetic resonance imaging and spectroscopy at ultra high fields

    International Nuclear Information System (INIS)

    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

  9. 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

  10. Evaluation of ISABELLE full cell ultra high vacuum system

    International Nuclear Information System (INIS)

    The ISABELLE Full Cell Vacuum System consisting of a 40 m long, by 8.8 cm diameter stainless steel tube pumped by seven pumping stations was assembled and processed for 10-12 Torr operation. Evaluation and testing of the system and its sub-assemblies has been completed. Detail design of system components and the determination of the conditioning process was completed. The best procedure to rough pump, leak test, vacuum bake the system, condition pumps, degas gauges, turn on ion pumps and flash sublimation pumps was established. Pressures below 2 x 10-11 Torr are now routinely achieved in normal operation of the Full Cell. This includes pump down after replacement of various components and pump down after back fill with moist unfiltered air. The techniques developed for the Full Cell will be used to build the ISABELLE Ultra High Vacuum System

  11. Ultra-high-ohmic microstripline resistors for Coulomb blockade devices.

    Science.gov (United States)

    Lotkhov, Sergey V

    2013-06-14

    In this paper, we report on the fabrication and low-temperature characterization of ultra-high-ohmic microstripline resistors made of a thin film of weakly oxidized titanium. Nearly linear voltage-current characteristics were measured at temperatures down to T ~ 20 mK for films with sheet resistivities as high as ~7 kΩ, i.e. about an order of magnitude higher than our previous findings for weakly oxidized Cr. Our analysis indicates that such an improvement can help to create an advantageous high-impedance environment for different Coulomb blockade devices. Further properties of the Ti film addressed in this work show the promise of low-noise behavior of the resistors when applied in different realizations of the quantum standard of current. PMID:23670293

  12. Holographic memory module with ultra-high capacity and throughput

    Energy Technology Data Exchange (ETDEWEB)

    Vladimir A. Markov, Ph.D.

    2000-06-04

    High capacity, high transfer rate, random access memory systems are needed to archive and distribute the tremendous volume of digital information being generated, for example, the human genome mapping and online libraries. The development of multi-gigabit per second networks underscores the need for next-generation archival memory systems. During Phase I we conducted the theoretical analysis and accomplished experimental tests that validated the key aspects of the ultra-high density holographic data storage module with high transfer rate. We also inspected the secure nature of the encoding method and estimated the performance of full-scale system. Two basic architectures were considered, allowing for reversible compact solid-state configuration with limited capacity, and very large capacity write once read many memory system.

  13. Demonstration of ultra high resolution soft x-ray tomography

    International Nuclear Information System (INIS)

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows which were separated by ∼ 5μm. Depth resolution comparable to the transverse resolution was achieved by recording nine 2-D images of the object at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image using an algebraic reconstruction technique (ART) algorithm. We observed a transverse resolution of ∼1000 A. Artifacts in the reconstruction limited the overall depth resolution to ∼6000 A, however some features were clearly reconstructed with a depth resolution of ∼1000 A

  14. Demonstration of ultra high resolution soft x-ray tomography

    Science.gov (United States)

    Haddad, W. S.; McNulty, I.; Trebes, J. E.; Anderson, E. H.; Yang, L.; Brase, J. M.

    1995-05-01

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows which were separated by ˜ 5μm. Depth resolution comparable to the transverse resolution was achieved by recording nine 2-D images of the object at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image using an algebraic reconstruction technique (ART) algorithm. We observed a transverse resolution of ˜1000 Å. Artifacts in the reconstruction limited the overall depth resolution to ˜6000 Å, however some features were clearly reconstructed with a depth resolution of ˜1000 Å.

  15. Micro-damage propagation in ultra-high vacuum seals

    International Nuclear Information System (INIS)

    The paper addresses a fundamental problem of tightness of ultra-high vacuum systems (UHV) at cryogenic temperatures in the light of continuum damage mechanics (CDM). The problem of indentation of a rigid punch into an elastic-plastic half-space is investigated based on rate independent plasticity with mixed kinematic and isotropic hardening. The micro-damage fields are modeled by using an anisotropic approach with a kinetic law of damage evolution suitable for ductile materials and cryogenic temperatures. The model has been experimentally validated and the results are used to predict the onset of macro-cracking (loss of tightness) and the corresponding load (contact pressure). The algorithm is applied in the design of UHV systems for particle accelerators.

  16. Bufferless Ultra-High Speed All-Optical Packet Routing

    Science.gov (United States)

    Muttagi, Shrihari; Prince, Shanthi

    2011-10-01

    All-Optical network is still in adolescence to cope up with steep rise in data traffic at the backbone network. Routing of packets in optical network depends on the processing speed of the All-Optical routers, thus there is a need to enhance optical processing to curb the delay in packet forwarding unit. In the proposed scheme, the header processing takes place on fly, therefore processing delay is at its lower limit. The objective is to propose a framework which establishes high data rate transmission with least latency in data routing from source to destination. The Routing table and optical header pulses are converted into Pulse Position (PP) format, thus reducing the complexity and in turn the processing delay. Optical pulse matching is exercised which results in multi-output transmission. This results in ultra-high speed packet forwarding unit. In addition, this proposed scheme includes dispersion compensation unit, which makes the data reliable.

  17. 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.

  18. Micro-damage propagation in ultra-high vacuum seals

    CERN Document Server

    Lutkiewicz, P; Garion, C

    2010-01-01

    The paper addresses a fundamental problem of tightness of ultra-high vacuum systems (UHV) at cryogenic temperatures in the light of continuum damage mechanics (CDM). The problem of indentation of a rigid punch into an elastic-plastic half-space is investigated based on rate independent plasticity with mixed kinematic and isotropic hardening. The micro-damage fields are modeled by using an anisotropic approach with a kinetic law of damage evolution suitable for ductile materials and cryogenic temperatures. The model has been experimentally validated and the results are used to predict the onset of macro-cracking (loss of tightness) and the corresponding load (contact pressure). The algorithm is applied in the design of UHV systems for particle accelerators. (C) 2009 Published by Elsevier Ltd.

  19. Oxidation of Ultra-High Temperature Ceramics in Water Vapor

    Science.gov (United States)

    Nguyen, QuynGiao N.; Robinson, Raymond C.; Opila, Elizabeth J.

    2004-01-01

    Ultra High Temperature Ceramics (UHTCs) including HfB2 + 20% SiC (HS), and ZrB2 + 20% SiC (ZC), and ZrB2 + 30% C + 14% SiC (ZCS) have been investigated for use as potential aeropropolsion engine materials. These materials were oxidized in water vapor (90%) using a cyclic vertical furnace at 1 atm. The total exposure time was 10 hours at temperature of 1200, 1300, and 1400 C. CVD SiC was also evaluate as a baseline for comparison. Weight change, X-ray diffraction analysis, surface and cross-sectional SEM and EDS were performed. These results are compared with tests conducted in a stagnant air furnace at temperatures of 1327 C for 100 minutes, and with high pressure burner rig (HPBR) results at 1100 and 1300 C at 6 atm for 50 h. Total recession measurements are also reported for the two tests environments.

  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. Ultra-high speed communications based on solitons in fibers

    Science.gov (United States)

    Hasegawa, Akira

    2000-10-01

    The citation of the Maxwell prize reads: ``For innovative discoveries and seminal contributions to the theories of nonlinear drift wave turbulence, Alfvén wave propagation in laboratory and space plasmas, and optical solitons and their application to high speed communication". The prize is given to three somewhat unrelated contributions made during the course of my career as a plasma physicist. Traditionally an award talk summarizes works related to the citation. However, because of the diversified contents of the citations, I prepared my talk with the focus only on the last topic because some of the audience may be of more expertise on the other subjects. I apologize for the fact that the talk may be worth only one third of the prize. Multi-Terabits’s, ultra-high speed optical transmissions over several thousand kilometers on fibers are becoming reality and are expected to serve as the trunk line for highly demanded Internet traffics. Most of them use soliton or soliton-like RZ (Return to Zero) format in fibers with properly managed (group velocity) dispersion. These formats are the only stable envelope waveforms of light waves in fibers in the presence of Kerr (cubic) nonlineariy and dispersion with loss compensated by periodic optical amplifications. In practice, the transmission systems utilize the all-optical transmission concept and the nonlinear Schrodinger equation assisted by the split step numerical solutions as the master equation to describe the information transfer in fibers. All these facts are the outcome of research on optical solitons in fibers. The talk presents a brief historical development of the soliton based high-speed communications followed by current status of ultra-high speed communications by means of solitons as well as by other formats. Although the talk may not be of a core interest of plasma physics community, it presents an interesting example of a useful by-product of plasma physics research.

  2. Ultra-high vacuum compatible optical chopper system for synchrotron x-ray scanning tunneling microscopy

    International Nuclear Information System (INIS)

    High-speed beam choppers are a crucial part of time-resolved x-ray studies as well as a necessary component to enable elemental contrast in synchrotron x-ray scanning tunneling microscopy (SX-STM). However, many chopper systems are not capable of operation in vacuum, which restricts their application to x-ray studies with high photon energies, where air absorption does not present a significant problem. To overcome this limitation, we present a fully ultra-high vacuum (UHV) compatible chopper system capable of operating at variable chopping frequencies up to 4 kHz. The lightweight aluminum chopper disk is coated with Ti and Au films to provide the required beam attenuation for soft and hard x-rays with photon energies up to about 12 keV. The chopper is used for lock-in detection of x-ray enhanced signals in SX-STM

  3. Ultra-high vacuum compatible optical chopper system for synchrotron x-ray scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hao, E-mail: hc000211@ohio.edu [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Nanoscale and Quantum Phenomena Institute, Physics & Astronomy Department, Ohio University, Athens, Ohio 45701 (United States); Cummings, Marvin; Shirato, Nozomi; Stripe, Benjamin; Preissner, Curt; Freeland, John W. [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Rosenmann, Daniel [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Kersell, Heath; Hla, Saw-Wai [Nanoscale and Quantum Phenomena Institute, Physics & Astronomy Department, Ohio University, Athens, Ohio 45701 (United States); Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Rose, Volker, E-mail: vrose@anl.gov [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

    2016-01-28

    High-speed beam choppers are a crucial part of time-resolved x-ray studies as well as a necessary component to enable elemental contrast in synchrotron x-ray scanning tunneling microscopy (SX-STM). However, many chopper systems are not capable of operation in vacuum, which restricts their application to x-ray studies with high photon energies, where air absorption does not present a significant problem. To overcome this limitation, we present a fully ultra-high vacuum (UHV) compatible chopper system capable of operating at variable chopping frequencies up to 4 kHz. The lightweight aluminum chopper disk is coated with Ti and Au films to provide the required beam attenuation for soft and hard x-rays with photon energies up to about 12 keV. The chopper is used for lock-in detection of x-ray enhanced signals in SX-STM.

  4. Coherent Control of Ultra-High Frequency Acoustic Resonances in Photonic Crystal Fibers

    CERN Document Server

    Wiederhecker, G S; Fragnito, H L; Russell, P St J

    2007-01-01

    UHF (ultra-high frequency) acoustic resonances (~2 GHz) trapped within the glass core (1 micron diameter) of a photonic crystal fibre are excited electrostrictively using laser pulses of duration 100 ps and energy 500 pJ. Using precisely timed sequences of such driving pulses, we achieve coherent control of the acoustic resonances by constructive or destructive interference, demonstrating both enhancement and suppression of the vibrations. A sequence of resonantly-timed pulses (limited to 25 by the capacity of the erbium-doped fibre amplifier used) provides a 100-fold increase in the amplitude of the vibrational mode. The results are explained and interpreted using a semi-analytical theory, and supported by precise numerical simulations of the complex light-matter interaction.

  5. Consideration of ultra-high temperature nuclear heat sources for MHD conversion systems

    International Nuclear Information System (INIS)

    The nuclear technology reactors developed and tested in the Nuclear Engine Rocket Vehicle Application (NERVA) program operated with fuel exit gas temperatures in excess of 2600 K. This experience provided a significant ultra-high temperature technology base and design insight for commercial power applications. Design approaches to accommodate fission product retention and other key prevailing requirements are examined in view of the basic overriding functional requirements, and some interesting reconsiderations are suggested. Predicted overall system performance potentials for a 2000 K MHD conversion system and reactor parameter requirements are compared and related to existing technology status. Needed verification and development efforts are suggested. A reconsideration of basic design approaches is suggested that could open the door for immediate development of ultrahigh temperature nuclear heat sources for advanced energy systems

  6. Ultra-High Gradient S-band Linac for Laboratory and Industrial Applications

    International Nuclear Information System (INIS)

    A strong demand for high gradient structures arises from the limited real estate available for linear accelerators. RadiaBeam Technologies is developing a Doubled Energy Compact Accelerator (DECA) structure: an S-band standing wave electron linac designed to operate at accelerating gradients of up to 50 MV/m. In this paper, we present the radio-frequency design of the DECA S-band accelerating structure, operating at 2.856 GHz in the π-mode. The structure design is heavily influenced by NLC collaboration experience with ultra high gradient X-band structures; S-band, however, is chosen to take advantage of commonly available high power S-band klystrons.

  7. Dimmable sunlight-like organic light emitting diodes with ultra-high color rendering index

    Science.gov (United States)

    Wu, Jin-Han; Chi, Chien-An; Chiang, Chang-Lin; Chen, Guan-Yu; Lin, Yi-Ping; Chen, Cheng-Chang; Ho, Shu-Yi; Chen, Shih-Pu; Li, Jung-Yu

    2016-05-01

    We propose novel dimmable sunlight-like white organic light-emitting diodes that were fabricated using three luminophores to form an emitting spectrum similar to black body radiation at 2250 K with ultra-high color rendering index (CRI) value of 91, which nearly remained the constant at various luminance values ranging from 100 to more than 2500 cd/m2 at Commission Internationale de l'Eclairage chromaticity coordinates of (0.51, 0.41). Introducing charge modification layers suppressed the energy transfer between the emitting material layers and increased the probability of carrier recombination. Moreover, we reveal that covering long-wavelength ranges played a vital role in achieving high CRI values; the CRI values of a spectrum artificially shifted toward a long-wavelength direction (from 610 to 620 nm) remained constant, whereas those of a spectrum shifted toward a short-wavelength direction (from 610 to 600 nm) dropped to 79.

  8. 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.

  9. Application of a nanosecond laser pulse to evaluate dynamic hardness under ultra-high strain rate

    Science.gov (United States)

    Radziejewska, Joanna

    2016-04-01

    The paper presents results of experimental tests of plastic metals deformation generated by a shock wave induced by laser pulse. Tests were carried out on the Nd:YAG laser with a wavelength of 1064 nm and the laser pulse of 10 ns duration. The shock wave generate by the laser pulse was used to induced local plastic deformation of the material surface. The study examined the possibility of application the process to develop a new method of measuring the dynamic hardness of materials under ultra-high strain rate. It has been shown that the shock wave induced by the laser pulse with an energy of 0.35-1.22 J causes a repeatable plastic deformation of surface of commercially available metals and alloys without thermal effects on the surfaces. Based on the knowledge of an imprint geometry, it is possible to evaluate the dynamic hardness of materials at strain rate in the range of 107 s-1.

  10. 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 energy management applications is reported.

  11. 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...

  12. Ultra high performance concrete made with rice husk ash for reduced autogenous shrinkage

    NARCIS (Netherlands)

    Van Breugel, K.; Van Tuan, N.

    2014-01-01

    Ultra High Strength Concrete (UHPC) is generally made with low w/c mixtures and by adding silica fume. Low w/c mixtures, however, exhibit high autogenous shrinkage, while a high amount of silica fume increases the price of these mixtures. For designing ultra high strength mixtures with low autogenou

  13. 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.

  14. Radiation crosslinking of ultra high molecular weigh polyethylene

    International Nuclear Information System (INIS)

    The effect of γ-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 γ-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. MHD Modeling of Conductors at Ultra-High Current Density

    Energy Technology Data Exchange (ETDEWEB)

    Asay, J.R.; Desjarlais, M.P.; Douglas, M.R.; Frese, M.H.; Hall, C.A.; Morse, R.L.; Reisman, D.; Rosenthal, S.E.; Spielman, R.B.; Stygar, W.A.

    1999-06-30

    In conjunction with ongoing high-current experiments on Sandia National Laboratories' Z accelerator we have revisited a problem first described in detail by Heinz Knoepfel. MITLs of previous pulsed power accelerators have been in the 1-Tesla regime. Z's disc transmission line (downstream of the current addition) is in a 100-1200 Tesla regime, so its conductors cannot be modeled simply as static infinite conductivity boundaries. Using the MHD code MACH2 we have been investigating conductor hydrodynamics, characterizing the joule heating, magnetic field diffusion, and material deformation, pressure, and velocity over a range of current densities, current rise-times, and conductor materials. Three purposes of this work are ( 1) to quantify power flow losses owing to ultra-high magnetic fields, (2) to model the response of VISAR diagnostic samples in various configurations on Z, and (3) to incorporate the most appropriate equation of state and conductivity models into our MHD computations. Certain features are strongly dependent on the details of the conductivity model. Comparison with measurements on Z will be discussed.

  16. MHD Modeling of Conductors at Ultra-High Current Density

    International Nuclear Information System (INIS)

    In conjunction with ongoing high-current experiments on Sandia National Laboratories' Z accelerator, the authors have revisited a problem first described in detail by Heinz Knoepfel. Unlike the 1-Tesla MITLs of pulsed power accelerators used to produce intense particle beams, Z's disc transmission line (downstream of the current addition) is in a 100--1,200 Tesla regime, so its conductors cannot be modeled simply as static infinite conductivity boundaries. Using the MHD code MACH2 they have been investigating the conductor hydrodynamics, characterizing the joule heating, magnetic field diffusion, and material deformation, pressure, and velocity over a range of current densities, current rise-times, and conductor materials. Three purposes of this work are (1) to quantify power flow losses owing to ultra-high magnetic fields, (2) to model the response of VISAR diagnostic samples in various configurations on Z, and (3) to incorporate the most appropriate equation of state and conductivity models into the MHD computations. Certain features are strongly dependent on the details of the conductivity model

  17. Ultra high resolution soft x-ray tomography

    International Nuclear Information System (INIS)

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by ∼5 microm. A series of nine 2-D images of the object were recorded at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of ∼ 1,000 angstrom was observed. Artifacts in the reconstruction limited the overall depth resolution to ∼ 6,000 angstrom, however some features were clearly reconstructed with a depth resolution of ∼ 1,000 angstrom. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution, bringing it down to ∼ 1,200 angstrom overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range

  18. 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.

  19. 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...

  20. Vacuum improvements for ultra high charge state ion acceleration

    International Nuclear Information System (INIS)

    The installation of a second cryo panel has significantly improved the vacuum in the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The neutral pressure in the extraction region decreased from 1.2 x 10-6 down to about 7 x 10-7 Torr. The vacuum improvement reduces beam loss from charge changing collisions and enhances the cyclotron beam transmission, especially for the high charge state heavy ions. Tests with improved vacuum show the cyclotron transmission increased more than 50% (from 5.7% to 9.0%) for a Xe27+ at 603 MeV, more than doubled for a Bi41+ beam (from 1.9% to 4.6%) at 904 MeV and tripled for a U47+ beam (from 1.2% to 3.6%) at 1,115 MeV. At about 5 NeV/nucleon 92 enA (2.2 pnA) for Bi41+ and 14 enA (0.3 pnA) for U47+ were extracted ut of the 88-Inch Cyclotron Ion beams with charge states as high as U64+ have been produced by the LBNL AECR-U ion source and accelerated through the cyclotron for the first time. The beam losses for a variety of ultra high charge state ions were measured as a function of cyclotron pressure and compared with the calculations from the existing models

  1. Ultra high resolution soft x-ray tomography

    International Nuclear Information System (INIS)

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by ∼5μm. A series of nine 2-D images of the object were recorded at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of ∼1000 Angstrom was observed. Artifacts in the reconstruction limited the overall depth resolution to ∼6000 Angstrom, however some features were clearly reconstructed with a depth resolution of ∼1000 Angstrom. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to ∼1200 Angstrom overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range

  2. A new generation of ultra high strength steel pipelines

    International Nuclear Information System (INIS)

    For many years an increased demand for natural gas can be observed. Ultra high-strength pipelines with higher operating pressures and/or reduced wall thickness are a means to reduce transmission costs. Motivated by reduced investment costs (overcharge a few billion of dollars), tend towards the development of a new grade of pipeline steel with microalloying element for example Nb, that potentially lowers the total cost of long-distance gas pipelines by 5 - 15%. New long distance pipelines have budgets in excess of several billion dollars. This paper describes mechanical properties of new generation of pipelines steel with higher content of niobium and the influence the welding thermal cycles on the microstructure and brittle fracture resistance. The resistance to cold cracking has also been determined. It was found that the new steel has close properties to API X70 grade steels, but is cheaper in manufacturing and installation. The steel has been covered by the amended EN 10028-5 standard and proper modifications will also be made in other European standards. (author)

  3. Fiber-laser welding for ultra-high tensile strength steel and stainless steel

    International Nuclear Information System (INIS)

    Ultra-high tensile strength steel of 980 or 1150 MPa class has been often used for a large scale construction machine with lightweight parts because of transport weight limit. This steel needs its pre-processing before welding and has a tendency of delayed cracking, that requests a high welding technique with qualified welders. Austenitic stainless steel frequency used for nuclear energy related equipments has much strains caused by welding because of a large coefficient of thermal expansion. As a welding with small amount of its heat input and without a large size facility like a vacuum chamber, a fiber-laser welding was chosen to apply to equipments made of ultra-high tensile strength steel and stainless steel. Tensile and bending tests for I-butt and around 2mm root gap welded joints of high strength steel of 980 MPa showed their mechanical properties were similar to those of base metal. I-butt welded joints of high strength steel of 1150 MPa showed similar mechanical properties of base metal but as for root gap welded joint, a filler metal was not available. With filler metal of 980 MPa instead, the welded joints showed similar tensile strength of base metal but a crack occurred at the bending test according to the JIS welding procedure qualification specification. Application of fiber laser welding to stainless steel had been conducted successfully for I-butt welded joints of good penetration up to the plate thickness of 8mm. As an example, T-joint of mercury target vessel for J-PARC was produced by fiber laser welding, that became to apply to other nuclear equipments. (T. Tanaka)

  4. Local damage to Ultra High Performance Concrete structures caused by an impact of aircraft engine missiles

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Werner [Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute, Eckerstrasse 4, D-79104 Freiburg (Germany); Noeldgen, Markus, E-mail: mnoeldgen@schuessler-plan.d [Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute, Eckerstrasse 4, D-79104 Freiburg (Germany); Schuessler-Plan Engineering Ltd., St.-Franziskus-Str. 148, D-40470 Duesseldorf (Germany); Strassburger, Elmar; Thoma, Klaus [Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute, Eckerstrasse 4, D-79104 Freiburg (Germany); Fehling, Ekkehard [University of Kassel, Chair of Structural Concrete, Kurt-Wolters Str. 3, D-34109 Kassel (Germany)

    2010-10-15

    Research highlights: {yields} Experimental series on UHPC panels subjected to aircraft engine impact. {yields} Improved ballistic limit of fiber reinforced UHPC in comparison to conventional R/C. {yields} Detailed investigation of failure mechanisms of fiber reinforced UHPC panel. - Abstract: The impact of an aircraft engine missile causes high stresses, deformations and a severe local damage to conventional reinforced concrete. As a consequence the design of R/C protective structural elements results in components with rather large dimensions. Fiber reinforced Ultra High Performance Concrete (UHPC) is a concrete based material which combines ultra high strength, high packing density and an improved ductility with a significantly increased energy dissipation capacity due to the addition of fiber reinforcement. With those attributes the material is potentially suitable for improved protective structural elements with a reduced need for material resources. The presented paper reports on an experimental series of scaled aircraft engine impact tests with reinforced UHPC panels. The investigations are focused on the material behavior and the damage intensity in comparison to conventional concrete. The fundamental work of is taken as reference for the evaluation of the results. The impactor model of a Phantom F4 GE-J79 engine developed and validated by Sugano et al. is used as defined in the original work. In order to achieve best comparability, the experimental configuration and method are adapted for the UHPC experiments. With 'penetration', 'scabbing' and 'perforation' all relevant damage modes defined in are investigated so that a full set of results are provided for a representative UHPC structural configuration.

  5. Local damage to Ultra High Performance Concrete structures caused by an impact of aircraft engine missiles

    International Nuclear Information System (INIS)

    Research highlights: → Experimental series on UHPC panels subjected to aircraft engine impact. → Improved ballistic limit of fiber reinforced UHPC in comparison to conventional R/C. → Detailed investigation of failure mechanisms of fiber reinforced UHPC panel. - Abstract: The impact of an aircraft engine missile causes high stresses, deformations and a severe local damage to conventional reinforced concrete. As a consequence the design of R/C protective structural elements results in components with rather large dimensions. Fiber reinforced Ultra High Performance Concrete (UHPC) is a concrete based material which combines ultra high strength, high packing density and an improved ductility with a significantly increased energy dissipation capacity due to the addition of fiber reinforcement. With those attributes the material is potentially suitable for improved protective structural elements with a reduced need for material resources. The presented paper reports on an experimental series of scaled aircraft engine impact tests with reinforced UHPC panels. The investigations are focused on the material behavior and the damage intensity in comparison to conventional concrete. The fundamental work of is taken as reference for the evaluation of the results. The impactor model of a Phantom F4 GE-J79 engine developed and validated by Sugano et al. is used as defined in the original work. In order to achieve best comparability, the experimental configuration and method are adapted for the UHPC experiments. With 'penetration', 'scabbing' and 'perforation' all relevant damage modes defined in are investigated so that a full set of results are provided for a representative UHPC structural configuration.

  6. 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

  7. Ultra-high Density SNParray in Neuroblastoma Molecular Diagnostics

    Directory of Open Access Journals (Sweden)

    PeterF.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.

  8. Diffuse axonal injury at ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Christoph Moenninghoff

    Full Text Available Diffuse axonal injury (DAI is a specific type of traumatic brain injury caused by shearing forces leading to widespread tearing of axons and small vessels. Traumatic microbleeds (TMBs are regarded as a radiological marker for DAI. This study aims to compare DAI-associated TMBs at 3 Tesla (T and 7 T susceptibility weighted imaging (SWI to evaluate possible diagnostic benefits of ultra-high field (UHF MRI.10 study participants (4 male, 6 female, age range 20-74 years with known DAI were included. All MR exams were performed with a 3 T MR system (Magnetom Skyra and a 7 T MR research system (Magnetom 7 T, Siemens AG, Healthcare Sector, Erlangen, Germany each in combination with a 32-channel-receive coil. The average time interval between trauma and imaging was 22 months. Location and count of TMBs were independently evaluated by two neuroradiologists on 3 T and 7 T SWI images with similar and additionally increased spatial resolution at 7 T. Inter- and intraobserver reliability was assessed using the interclass correlation coefficient (ICC. Count and diameter of TMB were evaluated with Wilcoxon signed rank test.Susceptibility weighted imaging revealed a total of 485 TMBs (range 1-190, median 25 at 3 T, 584 TMBs (plus 20%, range 1-262, median 30.5 at 7 T with similar spatial resolution, and 684 TMBs (plus 41%, range 1-288, median 39.5 at 7 T with 10-times higher spatial resolution. Hemorrhagic DAI appeared significantly larger at 7 T compared to 3 T (p = 0.005. Inter- and intraobserver correlation regarding the counted TMB was high and almost equal 3 T and 7 T.7 T SWI improves the depiction of small hemorrhagic DAI compared to 3 T and may be supplementary to lower field strengths for diagnostic in inconclusive or medicolegal cases.

  9. Ultra high barrier materials for encapsulation of flexible organic electronics

    Science.gov (United States)

    Logothetidis, S.; Laskarakis, A.; Georgiou, D.; Amberg-Schwab, S.; Weber, U.; Noller, K.; Schmidt, M.; Küçükpinar-Niarchos, E.; Lohwasser, W.

    2010-09-01

    The encapsulation of the active layers (organic semiconductors, electrodes, transparent conductive oxides, etc.) of organic electronic devices developed onto flexible polymeric substrates is one of the most challenging issues in the rapidly emerging area of organic electronics. The importance for the protection of the active layers arises from the fact that these are very sensitive when they are subjected to the atmosphere, since the permeation of the atmosphere's water vapour (H2O) and oxygen (O2) gases induces corrosion effects, film delamination and finally, failure of the organic electronic device. In addition, the encapsulation layers contribute to the long-term stability of the whole device enabling its use in outdoor environments (e.g. in the case of flexible photovoltaic cells-OPVs). A promising approach for the encapsulation of flexible organic electronics includes the development of multilayers that consist of hybrid polymer materials and inorganic layers onto flexible polymeric substrates, such as poly(ethylene terephthalate) (PET). This approach leads to a significant improvement of the barrier performance of the whole structure, due to the synergetic effect of the confinement of the permeation to the defect zones of the inorganic layer, and the formation of chemical bonds between the hybrid polymer and the inorganic layer. The knowledge of their optical properties and their correlation with their barrier performance are of major importance since it will contribute towards the optimization of their functionality. In this work, we provide an overview on the results concerning the use of hybrid polymers as ultra high barrier materials and moreover we discuss on the effect of inclusion of SiO2 nano-particles on their optical properties and barrier performance.

  10. Oxidation of Ultra High Temperature Ceramics in Water Vapor

    Science.gov (United States)

    Nguyen, QuynhGiao N.; Opila, Elizabeth J.; Robinson, Raymond C.

    2004-01-01

    Ultra High Temperature Ceramics (UHTCs) including HfB2 + 20v/0 SiC (HS), ZrB2 + 20v/0 SiC (ZS), and ZrB2 + 30v/0 C + 14v/0 SiC (ZCS) have been investigated for use as potential aeropropulsion engine materials. These materials were oxidized in water vapor (90 percent) using a cyclic vertical furnace at 1 atm. The total exposure time was 10 h at temperatures of 1200, 1300, and 1400 C. CVD SiC was also evaluated as a baseline for comparison. Weight change, X-ray diffraction analyses, surface and cross-sectional SEM and EDS were performed. These results are compared with tests ran in a stagnant air furnace at temperatures of 1327 C for 100 min, and with high pressure burner rig (HPBR) results at 1100 and 1300 C at 6 atm for 50 h. Low velocity water vapor does not make a significant contribution to the oxidation rates of UHTCs when compared to stagnant air. The parabolic rate constants at 1300 C, range from 0.29 to 16.0 mg(sup 2)cm(sup 4)/h for HS and ZCS, respectively, with ZS results between these two values. Comparison of results for UHTCs tested in the furnace in 90 percent water vapor with HPBR results was difficult due to significant sample loss caused by spallation in the increased velocity of the HPBR. Total recession measurements are also reported for the two test environments.

  11. Ultra-high resolution and high-brightness AMOLED

    Science.gov (United States)

    Wacyk, Ihor; Ghosh, Amal; Prache, Olivier; Draper, Russ; Fellowes, Dave

    2012-06-01

    As part of its continuing effort to improve both the resolution and optical performance of AMOLED microdisplays, eMagin has recently developed an SXGA (1280×3×1024) microdisplay under a US Army RDECOM CERDEC NVESD contract that combines the world's smallest OLED pixel pitch with an ultra-high brightness green OLED emitter. This development is aimed at next-generation HMD systems with "see-through" and daylight imaging requirements. The OLED pixel array is built on a 0.18-micron CMOS backplane and contains over 4 million individually addressable pixels with a pixel pitch of 2.7 × 8.1 microns, resulting in an active area of 0.52 inches diagonal. Using both spatial and temporal enhancement, the display can provide over 10-bits of gray-level control for high dynamic range applications. The new pixel design also enables the future implementation of a full-color QSXGA (2560 × RGB × 2048) microdisplay in an active area of only 1.05 inch diagonal. A low-power serialized low-voltage-differential-signaling (LVDS) interface is integrated into the display for use as a remote video link for tethered systems. The new SXGA backplane has been combined with the high-brightness green OLED device developed by eMagin under an NVESD contract. This OLED device has produced an output brightness of more than 8000fL with all pixels on; lifetime measurements are currently underway and will presented at the meeting. This paper will describe the operational features and first optical and electrical test results of the new SXGA demonstrator microdisplay.

  12. Ultra-high peak rejection notch microwave photonic filter using a single silicon microring resonator.

    Science.gov (United States)

    Long, Yun; Wang, Jian

    2015-07-13

    We propose a simple scheme to realize ultra-high peak rejection notch microwave photonic filter (MPF) based on a single silicon microring resonator (MRR). Using the combination of a conventional phase modulator (PM), a tunable bandpass filter (TBF), and a silicon MRR to manipulate the phase and amplitude of optical sidebands resulting in a signal cancellation at the RF notch filter frequency, we experimentally demonstrate a notch MPF with an ultra-high peak rejection beyond 60 dB. The frequency tunability of the proposed ultra-high peak rejection MPF is also demonstrated in the experiment. PMID:26191836

  13. 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.

  14. Ultra-high strain rate behavior of FCC nanostructures

    Science.gov (United States)

    Crum, Ryan Scott

    This work addresses the influence of ultra-high strain rates loading observed in our world today via ballistics, explosions and astrophysical collisions on well-defined metal structures. There is a plentiful amount of research examining metals at a macroscopic level that are subjected to ballistics and explosions but observing the microstructure is difficult as those procedures are fairly destructive testing mechanisms. Therefore, to understand the true mechanisms that occur in these loading situations a more novel technique is necessary. Modifications were made to the Laser Spallation Technique in order to load structures under a single transient wave pulse. This study characterized FCC nanostructures shock loaded at extreme pressures, strain rates and temperatures. By utilizing nanostructures, extremely large values of stain could be produced within the structure. It was first observed that at lower laser fluence levels and subsequently low stress states that there was a chemical activation of the surface of Cu nanopillars. This occurred due to nanofacet formation on the surface of the nanopillars which left pristine Cu surfaces to recombine with the environment. Dislocation motion was also observed and clearly identified in Cu nanopillars, Cu nanobenches and Al nanopillars. Further studies analyzed Cu nanopillars subjected to higher laser fluence generated stress waves, which led to bending and axial shortening deformation. These deformations were observed at laser fluence values of 144 kJ/m2 for bending and 300 kJ/m 2 for bulging similar to that of Taylor Impact experiments. To explore an even more extreme loading environment, a specialized test setup was employed to cryogenically cool the copper nanopillars to a temperature of 83K in an attempt to elucidate brittle behavior. Under these loading conditions the nanopillars continued to deform in a ductile manner but with delayed onset of both bending deformation and bulging deformation compared to the room

  15. 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....

  16. 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.

  17. Generation, insulated confinement, and heating of ultra-high temperature plasmas

    International Nuclear Information System (INIS)

    This invention relates to the production and maintenance in steady state of ultra-high temperature confined plasmas, particularly those created by full ionization of a volume of some hydrogenic gas such as deuterium. The target mass is surrounded with an ambient fluid medium at a predetermined pressure. Pulsed energy is projected upon the target mass to bring it to a predetermined temperature and to fully ionize it; this energy may be pulsed photon energy or pulsed particle-beam kinetic energy. An electrostatic double layer is formed spontaneously between the ionized mass and the ambient medium, providing thermal insulation and leaving the dominant energy loss to be bremmstrahlung losses. The bremmstrahlung losses are compensated for completely by supplying additional radiant energy to the ionized mass to maintain its temperature. The frequency range of the additional radiant energy is selected so as to be absorbable by the ionized mass, and its power level is adjusted to maintain the ionized mass in a substantially steady state. The static pressure of the ambient medium is increased, thereby equally increasing the static pressure of the ionized mass so as to enable the mass to absorb more of the radiant energy and increasing its temperature but also increasing its power losses. Simultaneously the radius and temperature of the mass are monitored and the power level of the radiant energy supply is increased to as to compensate for the power losses. The minimum feasible size of the plasma is less than a centimeter in diameter, while there is no constraint on maximum feasible size. This invention may be practiced with commercially-available lasers and microwave beam generators

  18. 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.

  19. Quality of silicon convex lenses fabricated by ultra-high precision diamond machining

    OpenAIRE

    K. Abou-El-Hossein

    2013-01-01

    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 whe...

  20. 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...... and the fire resistance. Such a fibre reinforced ultra high-strength material has been used to develop a simple joint solution between slab elements in a column - slab building system....