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Sample records for air showers initiated

  1. Muon spectrum in air showers initiated by gamma rays

    NASA Technical Reports Server (NTRS)

    Stephens, S. A.; Streitmatter, R. E.

    1985-01-01

    An analytic representation for the invariant cross-section for the production of charged pions in gamma P interactions was derived by using the available cross-sections. Using this the abundance of muons in a gamma ray initiated air shower is calculated.

  2. Air Shower Simulations

    SciTech Connect

    Alania, Marco; Gomez, Adolfo V. Chamorro; Araya, Ignacio J.; Huerta, Humberto Martinez; Flores, Alejandra Parra; Knapp, Johannes

    2009-04-30

    Air shower simulations are a vital part of the design of air shower experiments and the analysis of their data. We describe the basic features of air showers and explain why numerical simulations are the appropriate approach to model the shower simulation. The CORSIKA program, the standard simulation program in this field, is introduced and its features, performance and limitations are discussed. The basic principles of hadronic interaction models and some gerneral simulation techniques are explained. Also a brief introduction to the installation and use of CORSIKA is given.

  3. Strong interactions in air showers

    SciTech Connect

    Dietrich, Dennis D.

    2015-03-02

    We study the role new gauge interactions in extensions of the standard model play in air showers initiated by ultrahigh-energy cosmic rays. Hadron-hadron events remain dominated by quantum chromodynamics, while projectiles and/or targets from beyond the standard model permit us to see qualitative differences arising due to the new interactions.

  4. A new study of shower age distribution in near vertical showers by EAS air shower array

    NASA Technical Reports Server (NTRS)

    Chaudhuri, N.; Basak, D. K.; Goswami, G. C.; Ghosh, B.

    1984-01-01

    The air shower array has been developed since it started operation in 1931. The array covering an area of 900 sq m now incorporates 21 particle density sampling detectors around two muon magnetic spectrographs. The air showers are detected in the size range 10 to the 4th power to 10 to the 6th power particles. A total of 11000 showers has so far been detected. Average values of shower age have been obtained in various shower size ranges to study the dependence of shower age on shower size. The core distance dependence of shower age parameter has also been analyzed for presentation.

  5. Nitrogen fluorescence in air for observing extensive air showers

    NASA Astrophysics Data System (ADS)

    Keilhauer, B.; Bohacova, M.; Fraga, M.; Matthews, J.; Sakaki, N.; Tameda, Y.; Tsunesada, Y.; Ulrich, A.

    2013-06-01

    Extensive air showers initiate the fluorescence emissions from nitrogen molecules in air. The UV-light is emitted isotropically and can be used for observing the longitudinal development of extensive air showers in the atmosphere over tenth of kilometers. This measurement technique is well-established since it is exploited for many decades by several cosmic ray experiments. However, a fundamental aspect of the air shower analyses is the description of the fluorescence emission in dependence on varying atmospheric conditions. Different fluorescence yields affect directly the energy scaling of air shower reconstruction. In order to explore the various details of the nitrogen fluorescence emission in air, a few experimental groups have been performing dedicated measurements over the last decade. Most of the measurements are now finished. These experimental groups have been discussing their techniques and results in a series of Air Fluorescence Workshops commenced in 2002. At the 8th Air Fluorescence Workshop 2011, it was suggested to develop a common way of describing the nitrogen fluorescence for application to air shower observations. Here, first analyses for a common treatment of the major dependences of the emission procedure are presented. Aspects like the contributions at different wavelengths, the dependence on pressure as it is decreasing with increasing altitude in the atmosphere, the temperature dependence, in particular that of the collisional cross sections between molecules involved, and the collisional de-excitation by water vapor are discussed.

  6. A new observable in extensive air showers

    NASA Astrophysics Data System (ADS)

    García Canal, C. A.; Illana, J. I.; Masip, M.; Sciutto, S. J.

    2016-12-01

    We find that the ratio rμe of the muon to the electromagnetic component of an extended air shower at the ground level provides an indirect measure of the depth Xmax of the shower maximum. This result, obtained with the air-shower code AIRES, is independent of the hadronic model used in the simulation. We show that the value of rμe in a particular shower discriminates its proton or iron nature with a 98% efficiency. We also show that the eventual production of forwardheavy quarks inside the shower may introduce anomalous values of rμe in isolated events.

  7. Muon production in extended air shower simulations.

    PubMed

    Pierog, T; Werner, K

    2008-10-24

    Whereas air shower simulations are very valuable tools for interpreting cosmic ray data, there is a long-standing problem: it is difficult to accommodate at the same time the longitudinal development of air showers and the number of muons measured on the ground. Using a new hadronic interaction model (EPOS) in air shower simulations produces much more muons, in agreement with results from the HiRes-MIA experiment. We find that this is mainly due to a better description of (anti) baryon production in hadronic interactions. This is an aspect of air shower physics which has been neglected so far.

  8. Lateral Distribution of Air Shower Signals and Initial Energy Spectrum above 1 PeV from IceTop

    NASA Astrophysics Data System (ADS)

    Klepser, S.; Kislat, F.; Kolanoski, H.; Niessen, P.; Van Overloop, A.

    With the present size of the IceTop air shower array it is possible to measure an energy spectrum in the range of 1 PeV to 100 PeV. To do so, a lateral pulse height fit was performed on all analysed showers. Therefore it is crucial to have a realistic parametrisation of the expected lateral distribution and the corresponding fluctuations of the measured tank signals. Since IceTop tanks do not measure particle numbers, but rather portions of deposited energy, the typically used lateral distribution functions like NKG do not apply. Hence, a suitable function was developed in a CORSIKA simulation study. Having two tanks separated by 10m at each detector station, it is furthermore possible to study local pulse height fluctuations directly in data. These are used to develop a parametrisation of the weights needed in the lateral fit procedure. We will present the results of these investigations and preliminary distributions of the resulting shower parameters.

  9. Simulation of gamma-initiated showers

    NASA Technical Reports Server (NTRS)

    Stamenov, Y.; Vancov, K.; Vodenicharova, T.

    1985-01-01

    The main average characteristics of muon, electron and hadron components of extensive air showers were calculate using a standard model of nuclear interaction. The obtained results are in good agreement with Tien Shan experimental data.

  10. Lateral distribution of radio emission and its dependence on air shower longitudinal development

    SciTech Connect

    Kalmykov, Nikolai N.; Konstantinov, Andrey A. E-mail: elan1980@mail.ru

    2012-12-01

    The lateral distribution function (LDF) of radio emission from an extensive air shower is considered as the basic signature sensitive to the shower longitudinal development and, as a consequence, to the mass of a primary cosmic ray's particle that initiated a given shower. The peculiarities in the LDF's structure as well as their sensitivity to the height of shower maximum are investigated and explained.

  11. Extensive Air Showers in the Classroom

    ERIC Educational Resources Information Center

    Badala, A.; Blanco, F.; La Rocca, P.; Pappalardo, G. S.; Pulvirenti, A.; Riggi, F.

    2007-01-01

    The basic properties of extensive air showers of particles produced in the interaction of a high-energy primary cosmic ray in the Earth's atmosphere are discussed in the context of educational cosmic ray projects involving undergraduate students and high-school teams. Simulation results produced by an air shower development code were made…

  12. Microwave detection of air showers with MIDAS

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

    MIDAS (MIcrowave Detector of Air Showers) is a prototype of a microwave telescope to detect extensive air showers: it images a 20°×10° region of the sky with a 4.5 m parabolic reflector and 53 feeds in the focal plane. It has been commissioned in March 2010 and is currently taking data. We present the design, performance and first results of MIDAS.

  13. High energy hadrons in extensive air showers

    NASA Technical Reports Server (NTRS)

    Tonwar, S. C.

    1985-01-01

    Experimental data on the high energy hadronic component in extensive air showers of energies approx. 10 to the 14 to 10 to the 16 eV when compared with expectations from Monte Carlo simulations have shown the observed showers to be deficient in high energy hadrons relative to simulated showers. An attempt is made to understand these anomalous features with more accurate comparison of observations with expectations, taking into account the details of the experimental system. Results obtained from this analysis and their implications for the high energy physics of particle interactions at energy approx. 10 to the 15 eV are presented.

  14. Energy determination of gamma-ray induced air showers observed by an extensive air shower array

    NASA Astrophysics Data System (ADS)

    Kawata, K.; Sako, T. K.; Ohnishi, M.; Takita, M.; Nakamura, Y.; Munakata, K.

    2017-03-01

    We propose a new energy estimator to determine the energies of gamma-ray induced air showers based on the lateral distribution of extensive air showers in the energy range between 10 TeV and 1000 TeV. We carry out a detailed Monte Carlo simulation assuming the Tibet air shower array located at an altitude of 4,300 m above sea level. We define S50, which denotes the particle density at 50 m from the air shower axis, as a new energy estimator. Using S50, the energy resolution is estimated to be approximately 16 % at 100 TeV in the range of the zenith angle 𝜃 < 20∘. We find S50 giving a better energy resolution than 27 % for the air shower size (N e) and 30 % for the sum of detected particles ( \\sum ρ ), which have been used so far, at 100 TeV. We also compare the reconstructed age distributions of gamma-ray induced air showers and hadronic cosmic-ray induced air showers. The age parameter may help to discriminate between primary gamma rays and hadronic cosmic rays.

  15. Search for bursts in air shower data

    NASA Technical Reports Server (NTRS)

    Bruce, T. E. G.; Clay, R. W.; Dawson, B. R.; Protheroe, R. J.; Blair, D. G.; Cinquini, P.

    1985-01-01

    There have been reports in recent years of the possible observation of bursts in air shower data. If such events are truly of an astrophysical nature then, they represent an important new class of phemonenon since no other bursts have been observed above the MeV level. The spectra of conventional gamma ray bursts are unknown at higher energies but their observed spectra at MeV energies appear generally to exhibit a steepening in the higher MeV range and are thus unlikely to extrapolate to measurable fluxes at air shower energies. An attempt has been made to look for deviations from randomness in the arrival times of air showers above approx. 10 to the 14th power eV with a number of systems and results so far are presented here. This work will be continued for a substantial period of ime with a system capable of recording bursts with multiple events down to a spacing of 4 microns. Earlier data have also been searched for the possible association of air shower events with a glitch of the Vela pulsar.

  16. Slope of the lateral density function of extensive air showers around the knee region as an indicator of shower age

    NASA Astrophysics Data System (ADS)

    Dey, Rajat K.; Dam, Sandip

    2016-11-01

    Analyzing simulated extensive air shower (EAS) events generated with the Monte Carlo code CORSIKA, this paper critically studies the characteristics of lateral distribution of electrons in EAS around the knee energy region of the energy spectrum of primary cosmic rays. The study takes into account the issue of the lateral shower age parameter as an indicator of the stage of development of showers in the atmosphere. The correlation of the lateral shower age parameter with other EAS observables is examined, using simulated data in the context of its possible use in a multi-parameter study of EAS, with a view to obtaining information about the nature of the shower initiating primaries at sea level EAS experiments. It is shown that the observed slope of the lateral density function in the 3-dimensional plot, at least for the KASCADE data, supports the idea of a transition from light to heavy mass composition around the knee.

  17. Acoustic detection of air shower cores

    NASA Astrophysics Data System (ADS)

    Gao, X.; Liu, Y.; Du, S.

    1985-08-01

    At an altitude of 1890m, a pre-test with an Air shower (AS) core selector and a small acoustic array set up in an anechoic pool with a volume of 20x7x7 cu m was performed, beginning in Aug. 1984. In analyzing the waveforms recorded during the effective working time of 186 hrs, three acoustic signals which cannot be explained as from any source other than AS cores were obtained, and an estimation of related parameters was made.

  18. Phenomenological model of nuclear primary air showers

    NASA Technical Reports Server (NTRS)

    Tompkins, D. R., Jr.; Saterlie, S. F.

    1976-01-01

    The development of proton primary air showers is described in terms of a model based on a hadron core plus an electromagnetic cascade. The muon component is neglected. The model uses three parameters: a rate at which hadron core energy is converted into electromagnetic cascade energy and a two-parameter sea-level shower-age function. By assuming an interaction length for the primary nucleus, the model is extended to nuclear primaries. Both models are applied over the energy range from 10 to the 13th power to 10 to the 21st power eV. Both models describe the size and age structure (neglecting muons) from a depth of 342 to 2052 g/sq cm.

  19. Atmospheric effects on extensive air showers observed with the surface detector of the Pierre Auger observatory

    NASA Astrophysics Data System (ADS)

    Pierre Auger Collaboration; Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E. J.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez-Muñiz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Anzalone, A.; Aramo, C.; Arganda, E.; Argirò, S.; Arisaka, K.; Arneodo, F.; Arqueros, F.; Asch, T.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avila, G.; Bäcker, T.; Badagnani, D.; Barber, K. B.; Barbosa, A. F.; Barroso, S. L. C.; Baughman, B.; Bauleo, P.; Beatty, J. J.; Beau, T.; Becker, B. R.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; Benzvi, S.; Berat, C.; Bernardini, P.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Bleve, C.; Blümer, H.; Boháčová, M.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Busca, N. G.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Carvalho, W.; Castellina, A.; Catalano, O.; Cazon, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Chye, J.; Clay, R. W.; Colombo, E.; Conceição, R.; Connolly, B.; Contreras, F.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Domenico, M.; de Donato, C.; de Jong, S. J.; de La Vega, G.; de Mello, W. J. M.; de Mello Neto, J. R. T.; de Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; Del Peral, L.; Deligny, O.; Della Selva, A.; Delle Fratte, C.; Dembinski, H.; di Giulio, C.; Diaz, J. C.; Diep, P. N.; Dobrigkeit, C.; D'Olivo, J. C.; Dong, P. N.; Dornic, D.; Dorofeev, A.; Dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Duvernois, M. A.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferrer, F.; Ferrero, A.; Fick, B.; Filevich, A.; Filipčič, A.; Fleck, I.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fulgione, W.; Gamarra, R. F.; Gambetta, S.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Garrido, X.; Gelmini, G.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Goggin, L. M.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gonçalves, P.; Gonçalves Do Amaral, M.; Gonzalez, D.; Gonzalez, J. G.; Góra, D.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Gutiérrez, J.; Hague, J. D.; Halenka, V.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Healy, M. D.; Hebbeker, T.; Hebrero, G.; Heck, D.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Hrabovský, M.; Huege, T.; Hussain, M.; Iarlori, M.; Insolia, A.; Ionita, F.; Italiano, A.; Jiraskova, S.; Kaducak, M.; Kampert, K. H.; Karova, T.; Kasper, P.; Kégl, B.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapik, R.; Knapp, J.; Koang, D.-H.; Krieger, A.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; Kusenko, A.; La Rosa, G.; Lachaud, C.; Lago, B. L.; Lautridou, P.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Lee, J.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Leuthold, M.; Lhenry-Yvon, I.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Luna García, R.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Maris, I. C.; Marquez Falcon, H. R.; Martello, D.; Martínez, J.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McEwen, M.; McNeil, R. R.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Meyhandan, R.; Micheletti, M. I.; Miele, G.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Morris, C.; Mostafá, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Newman-Holmes, C.; Newton, D.; Nhung, P. T.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Ortolani, F.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Parente, G.; Parizot, E.; Parlati, S.; Pastor, S.; Patel, M.; Paul, T.; Pavlidou, V.; Payet, K.; Pech, M.; PeĶala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pinto, T.; Pirronello, V.; Pisanti, O.; Platino, M.; Pochon, J.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Redondo, A.; Reucroft, S.; Revenu, B.; Rezende, F. A. S.; Ridky, J.; Riggi, S.; Risse, M.; Rivière, C.; Rizi, V.; Robledo, C.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-D'Orfeuil, A.; Roulet, E.; Rovero, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E. M.; Sarazin, F.; 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.; Schroeder, F.; Schulte, S.; Schüssler, F.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shellard, R. C.; Sidelnik, I.; Siffert, B. B.; Smiałkowski, A.; Šmída, R.; Smith, B. E.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Tamashiro, A.; Tamburro, A.; Tarutina, T.; Taşcău, O.; Tcaciuc, R.; Tcherniakhovski, D.; Thao, N. T.; Thomas, D.; Ticona, R.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Torres, I.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tuci, V.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Velarde, A.; Venters, T.; Verzi, V.; Videla, M.; Villaseñor, L.; Vorobiov, S.; Voyvodic, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Wileman, C.; Winnick, M. G.; Wu, H.; Wundheiler, B.; Yamamoto, T.; Younk, P.; Yuan, G.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.

    2009-09-01

    Atmospheric parameters, such as pressure (P), temperature (T) and density (ρ∝P/T), affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ˜10% seasonal modulation and ˜2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of P and ρ. The former affects the longitudinal development of air showers while the latter influences the Molière radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.

  20. A new study of muons in air showers by NBU air shower array

    NASA Technical Reports Server (NTRS)

    Chaudhuri, N.; Mukherjee, N.; Sarkar, S.; Basak, D. K.; Ghosh, B.

    1985-01-01

    The North Bengal University (NBU) air shower array has been in operation in conjunction with two muon magnetic spectrographs. The array incorporates 21 particle density sampling detectors around the magnetic spectrographs covering an area of 900 sq m. The layout of the array is based on the arrangement of detectors in a square symmetry. The array set up on the ground level is around a 10 m high magnetic spectrograph housing. This magnetic spectrograph housing limits the zenith angular acceptance of the incident showers to a few degrees. Three hundred muons in the fitted showers of size range 10 to the 4th power to 10 to the 5th power particles have so far been scanned and the momenta determined in the momentum range 2 - 440 GeV/c. More than 1500 recorded showers are now in the process of scanning and fitting. A lateral distribution of muons of energy greater than 300 MeV in the shower size range 10 to the 5th power to 7 x 10 to the 5th power has been obtained.

  1. Angular resolution of the Ohya air shower detector

    NASA Astrophysics Data System (ADS)

    Mitsui, K.; Aoki, T.; Okada, A.; Ohashi, Y.; Muraki, Y.; Shibata, S.; Nakamura, I.; Kojima, H.; Kitamura, T.; Minorikawa, Y.; Kato, Y.; Takahashi, T.; Higashi, S.; Kobayakawa, K.; Kamiya, Y.

    1990-05-01

    Accurate measurements of the total number of muons in an air shower are important for the discrimination of showers produced by astronomical gamma rays from those produced by protons. In order to perform this discrimination, muon detectors with a total area of about 400 m2 have been constructed in the Ohya stone mine. At ground level, scintillation detectors have been distributed for determining the total number of electrons in the air shower. The arrival direction of the air shower determined by usual timing information was examined using independent data on the arrival direction determined by muons in the shower. The angular resolution thus obtained at the shower maximum is 1.7° in the south-north plane and 2° in the east-west plane. The difference of the resolution is due to the asymmetric arrangement of scintillation detectors.

  2. Size distributions of air showers accompanied with high energy gamma ray bundles observed at Mt. Chacaltaya

    NASA Technical Reports Server (NTRS)

    Matano, T.; Machida, M.; Tsuchima, I.; Kawasumi, N.; Honda, K.; Hashimoto, K.; Martinic, N.; Zapata, J.; Navia, C. E.; Aquirre, C.

    1985-01-01

    Size distributions of air showers accompanied with bundle of high energy gamma rays and/or large size bursts under emulsion chambers, to study the composition of primary cosmic rays and also characteristics of high energy nuclear interaction. Air showers initiated by particles with a large cross section of interaction may develop from narrow region of the atmosphere near the top. Starting levels of air showers by particles with smaller cross section fluctuate in wider region of the atmosphere. Air showers of extremely small size accompanied with bundle of gamma rays may be ones initiated by protons at lower level after penetrating deep atmosphere without interaction. It is determined that the relative size distribution according to the total energy of bundle of gamma rays and the total burst size observed under 15 cm lead absorber.

  3. Small air showers and collider physics

    NASA Technical Reports Server (NTRS)

    Capdevielle, J. N.; Gawin, J.; Grochalska, B.

    1985-01-01

    At energies lower than 2.5 X 10 to the 5 GeV (in Lab. system), more accurate information on nucleon-nucleon collision (p-p collider and on primary composition now exist. The behavior of those both basic elements in cosmic ray phenomenology from ISR energy suggests some tendencies for reasonable extrapolation in the next decade 2.0x10 to the 5 to 2.0x10 to the 6 GeV. Small showers in altitude, recorded in the decade 2 X 10 to the 4 to 2 X 10 to the 5 GeV offers a good tool to testify the validity of all the Monte-Carlo simulation analysis and appreciate how nucleon-air collision are different from nucleon-nucleon collisions.

  4. AIR TOXICS EMISSIONS FROM A VINYL SHOWER CURTAIN

    EPA Science Inventory

    The paper reports results of both static and dynamic chamber tests conducted to evaluate emission characteristics of air toxics from a vinyl shower Curtain. (NOTE: Due to the relatively low price and ease of installation, vinyl shower curtains have been widely used in bathrooms i...

  5. Depth Distribution Of The Maxima Of Extensive Air Shower

    NASA Technical Reports Server (NTRS)

    Adams, J. H.; Howell, L. W.

    2003-01-01

    Observations of the extensive air showers from space can be free from interference by low altitude clouds and aerosols if the showers develop at a sufficiently high altitude. In this paper we explore the altitude distribution of shower maxima to determine the fraction of all showers that will reach their maxima at sufficient altitudes to avoid interference from these lower atmosphere phenomena. Typically the aerosols are confined within a planetary boundary layer that extends from only 2-3 km above the Earth's surface. Cloud top altitudes extend above 15 km but most are below 4 km. The results reported here show that more than 75% of the showers that will be observed by EUSO have maxima above the planetary boundary layer. The results also show that more than 50% of the showers that occur on cloudy days have their maxima above the cloud tops.

  6. Probing the radio emission from air showers with polarization measurements

    NASA Astrophysics Data System (ADS)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bardenet, R.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; 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.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Foerster, N.; Fox, B. D.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giammarchi, M.; Giller, M.; Gitto, J.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kadija, K.; Kambeitz, O.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; PeÂķala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Pontz, M.; Porcelli, A.; Preda, T.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Straub, 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.; Taşcǎu, O.; Thao, N. T.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Tridapalli, D. B.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Pierre Auger Collaboration

    2014-03-01

    The emission of radio waves from air showers has been attributed to the so-called geomagnetic emission process. At frequencies around 50 MHz this process leads to coherent radiation which can be observed with rather simple setups. The direction of the electric field induced by this emission process depends only on the local magnetic field vector and on the incoming direction of the air shower. We report on measurements of the electric field vector where, in addition to this geomagnetic component, another component has been observed that cannot be described by the geomagnetic emission process. The data provide strong evidence that the other electric field component is polarized radially with respect to the shower axis, in agreement with predictions made by Askaryan who described radio emission from particle showers due to a negative charge excess in the front of the shower. Our results are compared to calculations which include the radiation mechanism induced by this charge-excess process.

  7. Simulation of the Radiation Energy Release in Air Showers

    NASA Astrophysics Data System (ADS)

    Glaser, Christian; Erdmann, Martin; Hörandel, Jörg R.; Huege, Tim; Schulz, Johannes

    2017-03-01

    A simulation study of the energy released by extensive air showers in the form of MHz radiation is performed using the CoREAS simulation code. We develop an efficient method to extract this radiation energy from air-shower simulations. We determine the longitudinal profile of the radiation energy release and compare it to the longitudinal profile of the energy deposit by the electromagnetic component of the air shower. We find that the radiation energy corrected for the geometric dependence of the geomagnetic emission scales quadratically with the energy in the electromagnetic component of the air shower with a second order dependency on the atmospheric density at the position of the maximum of the shower development Xmax. In a measurement where Xmax is not accessible, this second order dependence can be approximated using the zenith angle of the incoming direction of the air shower with only a minor deterioration in accuracy. This method results in an intrinsic uncertainty of 4% with respect to the electromagnetic shower energy which is well below current experimental uncertainties.

  8. Polarized radio emission from extensive air showers measured with LOFAR

    SciTech Connect

    Schellart, P.; Buitink, S.; Corstanje, A.; Enriquez, J.E.; Falcke, H.; Hörandel, J.R.; Krause, M.; Nelles, A.; Rachen, J.P.; Veen, S. ter; Thoudam, S.

    2014-10-01

    We present LOFAR measurements of radio emission from extensive air showers. We find that this emission is strongly polarized, with a median degree of polarization of nearly 99%, and that the angle between the polarization direction of the electric field and the Lorentz force acting on the particles, depends on the observer location in the shower plane. This can be understood as a superposition of the radially polarized charge-excess emission mechanism, first proposed by Askaryan and the geomagnetic emission mechanism proposed by Kahn and Lerche. We calculate the relative strengths of both contributions, as quantified by the charge-excess fraction, for 163 individual air showers. We find that the measured charge-excess fraction is higher for air showers arriving from closer to the zenith. Furthermore, the measured charge-excess fraction also increases with increasing observer distance from the air shower symmetry axis. The measured values range from (3.3± 1.0)% for very inclined air showers at 25 m to (20.3± 1.3)% for almost vertical showers at 225 m. Both dependencies are in qualitative agreement with theoretical predictions.

  9. Modelling of radio emission from cosmic ray air showers

    NASA Astrophysics Data System (ADS)

    Ludwig, Marianne

    2011-06-01

    Cosmic rays entering the Earth's atmosphere induce extensive air showers consisting of up to billions of secondary particles. Among them, a multitude of electrons and positrons are generated. These get deflected in the Earth's magnetic field, creating time-varying transverse currents. Thereby, the air shower emits coherent radiation in the MHz frequency range measured by radio antenna arrays on the ground such as LOPES at the KIT. This detection method provides a possibility to study cosmic rays with energies above 1017 eV. At this time, the radio technique undergoes the change from prototype experiments to large scale application. Thus, a detailed understanding of the radio emission process is needed more than ever. Before starting this work, different models made conflicting predictions on the pulse shape and the amplitude of the radio signal. It turned out that a radiation component caused by the variation of the number of charged particles within the air shower was missed in several models. The Monte Carlo code REAS2 superposing the radiation of the individual air shower electrons and positrons was one of those. At this time, it was not known how to take the missing component into account. For REAS3, we developed and implemented the endpoint formalism, a universal approach, to calculate the radiation from each single particle. For the first time, we achieve a good agreement between REAS3 and MGMR, an independent and completely different simulation approach. In contrast to REAS3, MGMR is based on a macroscopic approach and on parametrisations of the air shower. We studied the differences in the underlying air shower models to explain the remaining deviations. For comparisons with LOPES data, we developed a new method which allows "top-down" simulations of air showers. From this, we developed an air shower selection criterion based on the number of muons measured with KASCADE to take shower-to-shower fluctuations for a single event analysis into account. With

  10. TANGO ARRAY I: An Air Shower Experiment in Buenos Aires

    NASA Astrophysics Data System (ADS)

    Bauleo, P.; Bonifazi, C.; Filevich, A.; Reguera, A.

    The TANGO Array is an air shower experiment which has been recently constructed in Buenos Aires, Argentina. It became fully operational in September, 2000. The array consists of 4 water ˇCerenkov detector stations enclosing a geometrical area of ˜ 30.000 m2 and its design has been optimized for the observation of EAS produced by cosmic rays near the "knee" energy region. Three of the detectors have been constructed using 12000-liter stainless steel tanks, and the fourth has been mounted in a smaller, 400liter plastic container. The detectors are connected by cables to the data acquisition room, where a fully automatic system, which takes advantage of the features of a 4-channel digital oscilloscope, was set for data collection without the need of operator intervention. This automatic experiment control includes monitoring, data logging, and daily calibration of all stations. This paper describes the detectors and their associated electronics, and details are given on the data acquisition system, the triggering and calibration procedures, and the operation of the array. Examples of air shower traces, recorded by the array, are presented.

  11. Arrival directions of large air showers, low-mu showers and old-age low-mu air showers observed at St. Chacaltaya

    NASA Technical Reports Server (NTRS)

    Kaneko, T.; Hagiwara, K.; Yoshii, H.; Martinic, N.; Siles, L.; Miranda, P.; Kakimoto, F.; Obara, T.; Inoue, N.; Suga, K.

    1985-01-01

    Arrival directions of air showers with primary energies in the range 10 to the 16.5 power eV to 10 to the 18th power eV show the first harmonic in right ascension (RA) with amplitude of 2.7 + or - 1.0% and phase of 13-16h. However, the second harmonic in RA slightly seen for showers in the range 10 to the 18th power eV to 10 to the 19th power eV disappeared by accumulation of observed showers. The distribution of arrival directions of low-mu air showers with primary energies around 10 to the 15th power eV observed at Chacaltaya from 1962 to 1967 is referred to, relating to the above-mentioned first harmonic. Also presented in this paper are arrival directions of old-age low-mu air showers observed at Chacaltaya from 1962 to 1967, for recent interest in gamma-ray air showers.

  12. Extreme atmospheric electron densities created by extensive air showers

    NASA Astrophysics Data System (ADS)

    Rutjes, Casper; Camporeale, Enrico; Ebert, Ute; Buitink, Stijn; Scholten, Olaf; Trinh, Gia

    2016-04-01

    A sufficient density of free electrons and strong electric fields are the basic requirements to start any electrical discharge. In the context of thunderstorm discharges it has become clear that in addition droplets and or ice particles are required to enhance the electric field to values above breakdown. In our recent study [1] we have shown that these three ingredients have to interplay to allow for lightning inception, triggered by an extensive air shower event. The extensive air showers are a very stochastic natural phenomenon, creating highly coherent bursts of extreme electron density in our atmosphere. Predicting these electron density bursts accurately one has to take the uncertainty of the input variables into account. To this end we use uncertainty quantification methods, like in [2], to post-process our detailed Monte Carlo extensive air shower simulations, done with the CORSIKA [3] software package, which provides an efficient and elegant way to determine the distribution of the atmospheric electron density enhancements. We will present the latest results. [1] Dubinova, A., Rutjes, C., Ebert, E., Buitink, S., Scholten, O., and Trinh, G. T. N. "Prediction of Lightning Inception by Large Ice Particles and Extensive Air Showers." PRL 115 015002 (2015) [2] G.J.A. Loeven, J.A.S. Witteveen, H. Bijl, Probabilistic collocation: an efficient nonintrusive approach for arbitrarily distributed parametric uncertainties, 45th AIAA Aerospace Sciences Meeting, Reno, Nevada, 2007, AIAA-2007-317 [3] Heck, Dieter, et al. CORSIKA: A Monte Carlo code to simulate extensive air showers. No. FZKA-6019. 1998.

  13. A Fast Hybrid Approach to Air Shower Simulations and Applications

    NASA Astrophysics Data System (ADS)

    Drescher, H.-J.; Farrar, Glennys; Bleicher, Marcus; Reiter, Manuel; Soff, Sven; Stoecker, Horst

    2003-07-01

    The SENECA model, a new hybrid approach to air shower simulations, is presented. It combines the use of efficient cascade equations in the energy range where a shower can be treated as one-dimensional, with a traditional Monte Carlo method which traces individual particles. This allows one to repro duce natural fluctuations of individual showers as well as the lateral spread of low energy particles. The model is quite efficient in computation time. As an application of the new approach, the influence of the low energy hadronic models on shower properties for AUGER energies is studied. We conclude that these models have a significant impact on the tails of lateral distribution functions, and deserve therefore more attention.

  14. Analysis of extensive air showers with the hybrid code SENECA

    NASA Astrophysics Data System (ADS)

    Ortiz, Jeferson A.; de Souza, Vitor; Medina-Tanco, Gustavo

    The ultrahigh energy tail of the cosmic ray spectrum has been explored with unprecedented detail. For this reason, new experiments are exerting a severe pressure on extensive air shower modeling. Detailed fast codes are in need in order to extract and understand the richness of information now available. In this sense we explore the potential of SENECA, an efficient hybrid tridimensional simulation code, as a valid practical alternative to full Monte Carlo simulations of extensive air showers generated by ultrahigh energy cosmic rays. We discuss the influence of this approach on the main longitudinal characteristics of proton, iron nucleus and gamma induced air showers for different hadronic interaction models. We also show the comparisons of our predictions with those of CORSIKA code.

  15. Cosmic Ray-Air Shower Measurement from Space

    NASA Technical Reports Server (NTRS)

    Takahashi, Yoshiyuki

    1997-01-01

    A feasibility study has been initiated to observe from space the highest energy cosmic rays above 1021 eV. A satellite observatory concept, the Maximum-energy Auger (Air)-Shower Satellite (MASS), is recently renamed as the Orbital Wide-angle Collector (OWL) by taking its unique feature of using a very wide field-of-view (FOV) optics. A huge array of imaging devices (about 10(exp 6) pixels) is required to detect and record fluorescent light profiles of cosmic ray cascades in the atmosphere. The FOV of MASS could extend to as large as about 60 in. diameter, which views (500 - 1000 km) of earth's surface and more than 300 - 1000 cosmic ray events per year could be observed above 1020 eV. From far above the atmosphere, the MASS/OWL satellite should be capable of observing events at all angles including near horizontal tracks, and would have considerable aperture for high energy photon and neutrino observation. With a large aperture and the spatial and temporal resolution, MASS could determine the energy spectrum, the mass composition, and arrival anisotropy of cosmic rays from 1020 eV to 1022 eV; a region hitherto not explored by ground-based detectors such as the Fly's Eye and air-shower arrays. MASS/OWL's ability to identify cosmic neutrinos and gamma rays may help providing evidence for the theory which attributes the above cut-off cosmic ray flux to the decay of topological defects. Very wide FOV optics system of MASS/OWL with a large array of imaging devices is applicable to observe other atmospheric phenomena including upper atmospheric lightning. The wide FOV MASS optics being developed can also improve ground-based gamma-ray observatories by allowing simultaneous observation of many gamma ray sources located at different constellations.

  16. The search for extended air showers at the Jicamarca Radio Observatory

    SciTech Connect

    Wahl, D.; Chau, J.; Galindo, F.; Huaman, A.; Solano, C. J.

    2009-04-30

    This paper presents the status of the project to detect extended air showers at the Jicamarca Radio Observatory. We report on detected anomalous signals and present a toy model to estimate at what altitudes we might expect to see air shower signals. According to this model, a significant number of high altitude horizontal air showers could be observed by radar techniques.

  17. Air shower detectors in gamma-ray astronomy

    SciTech Connect

    Sinnis, Gus

    2008-01-01

    Extensive air shower (EAS) arrays directly detect the particles in an EAS that reach the observation altitude. This detection technique effectively makes air shower arrays synoptic telescopes -- they are capable of simultaneously and continuously viewing the entire overhead sky. Typical air shower detectors have an effective field-of-view of 2 sr and operate nearly 100% of the time. These two characteristics make them ideal instruments for studying the highest energy gamma rays, extended sources and transient phenomena. Until recently air shower arrays have had insufficient sensitivity to detect gamma-ray sources. Over the past decade, the situation has changed markedly. Milagro, in the US, and the Tibet AS{gamma} array in Tibet, have detected very-high-energy gamma-ray emission from the Crab Nebula and the active galaxy Markarian 421 (both previously known sources). Milagro has discovered TeV diffuse emission from the Milky Way, three unidentified sources of TeV gamma rays, and several candidate sources of TeV gamma rays. Given these successes and the suite of existing and planned instruments in the GeV and TeV regime (AGILE, GLAST, HESS, VERITAS, CTA, AGIS and IceCube) there are strong reasons for pursuing a next generation of EAS detectors. In conjunction with these other instruments the next generation of EAS instruments could answer long-standing problems in astrophysics.

  18. Character of energy flow in air shower core

    NASA Technical Reports Server (NTRS)

    Mizushima, K.; Asakimori, K.; Maeda, T.; Kameda, T.; Misaki, Y.

    1985-01-01

    Energy per charged particle near the core of air showers was measured by 9 energy flow detectors, which were the combination of Cerenkov counters and scintillators. Energy per particle of each detector was normalized to energy at 2m from the core. The following results were obtained as to the energy flow: (1) integral frequency distribution of mean energy per particle (averaged over 9 detectors) is composed of two groups separated distinctly; and (2) showers contained in one group show an anisotropy of arrival direction.

  19. The AMY experiment: Microwave emission from air shower plasmas

    NASA Astrophysics Data System (ADS)

    Alvarez-Muñiz, J.; Blanco, M.; Boháčová, M.; Buonomo, B.; Cataldi, G.; Coluccia, M. R.; Creti, P.; De Mitri, I.; Di Giulio, C.; Facal San Luis, P.; Foggetta, L.; Gaïor, R.; Garcia-Fernandez, D.; Iarlori, M.; Le Coz, S.; Letessier-Selvon, A.; Louedec, K.; Maris, I. C.; Martello, D.; Mazzitelli, G.; Monasor, M.; Perrone, L.; Petrera, S.; Privitera, P.; Rizi, V.; Rodriguez Fernandez, G.; Salamida, F.; Salina, G.; Settimo, M.; Valente, P.; Vazquez, J. R.; Verzi, V.; Williams, C.

    2016-07-01

    You The Air Microwave Yield (AMY) experiment investigate the molecular bremsstrahlung radiation emitted in the GHz frequency range from an electron beam induced air-shower. The measurements have been performed at the Beam Test Facility (BTF) of Frascati INFN National Laboratories with a 510 MeV electron beam in a wide frequency range between 1 and 20 GHz. We present the apparatus and the results of the tests performed.

  20. Nanosecond Enhancements of the Atmospheric Electron Density by Extensive Air Showers

    NASA Astrophysics Data System (ADS)

    Rutjes, C.; Camporeale, E.; Ebert, U.; Buitink, S.; Scholten, O.; Trinh, G. T. N.; Witteveen, J.

    2015-12-01

    As is well known a sufficient density of free electrons and strong electric fields are the basic requirements to start any electrical discharge. In the context of thunderstorm discharges it has become clear that in addition droplets and or ice particles are required to enhance the electric field to values above breakdown. In our recent study [1] we have shown that these three ingredients have to interplay to allow for lightning inception, triggered by an extensive air shower event. The extensive air showers are a very stochastic natural phenomenon, creating highly coherent sub-nanosecond enhancements of the atmospheric electron density. Predicting these electron density enhancements accurately one has to take the uncertainty of the input variables into account. For this study we use the initial energy, inclination and altitude of first interaction, which will influence the evolution of the shower significantly. To this end, we use the stochastic collocation method, [2] to post-process our detailed Monte Carlo extensive air shower simulations, done with the CORSIKA [3] software package, which provides an efficient and elegant way to determine the distribution of the atmospheric electron density enhancements. [1] Dubinova, A., Rutjes, C., Ebert, E., Buitink, S., Scholten, O., and Trinh, G. T. N. "Prediction of Lightning Inception by Large Ice Particles and Extensive Air Showers." PRL 115 015002 (2015)[2] G.J.A. Loeven, J.A.S. Witteveen, H. Bijl, Probabilistic collocation: an efficient nonintrusive approach for arbitrarily distributed parametric uncertainties, 45th AIAA Aerospace Sciences Meeting, Reno, Nevada, 2007, AIAA-2007-317[3] Heck, Dieter, et al. CORSIKA: A Monte Carlo code to simulate extensive air showers. No. FZKA-6019. 1998.

  1. Radio Emission in Atmospheric Air Showers Measured by LOPES-30

    SciTech Connect

    Isar, P. G.

    2008-01-24

    When Ultra High Energy Cosmic Rays (UHECR) interact with particles in the Earth's atmosphere, they produce a shower of secondary particles propagating towards the ground. These relativistic particles emit synchrotron radiation in the radio frequency range when passing the Earth's magnetic field. The LOPES (LOFAR Prototype Station) experiment investigates the radio emission from these showers in detail and will pave the way to use this detection technique for large scale applications like in LOFAR (Low Frequency Array) and the Pierre Auger Observatory. The LOPES experiment is co-located and measures in coincidence with the air shower experiment KASCADE-Grande at Forschungszentrum Karlsruhe, Germany. LOPES has an absolute amplitude calibration array of 30 dipole antennas (LOPES-30). After one year of measurements of the single East-West polarization by all 30 antennas, recently, the LOPES-30 set-up was configured to perform dual-polarization measurements. Half of the antennas have been configured for measurements of the North-South polarization. Only by measuring at the same time both, the E-W and N-S polarization components of the radio emission, the geo-synchrotron effect as the dominant emission mechanism in air showers can be verified. The status of the measurements, including the absolute calibration procedure of the dual-polarized antennas as well as analysis of dual-polarized event examples are reported.

  2. Air fluorescence detection of large air showers below the horizon

    NASA Technical Reports Server (NTRS)

    Halverson, P.; Bowen, T.

    1985-01-01

    In the interest of exploring the cosmic ray spectrum at energies greater than 10 to the 18th power eV, where flux rates at the Earth's surface drop below 100 yr(-1) km(-2) sr(-1), cosmic ray physicists have been forced to construct ever larger detectors in order to collect useful amounts of data in reasonable lengths of time. At present, the ultimate example of this trend is the Fly's Eye system in Utah, which uses the atmosphere around an array of skyward-looking photomultiplier tubes. The air acts as a scintillator to give detecting areas as large as 5000 square kilometers sr (for highest energy events). This experiment has revealed structure (and a possible cutoff) in the ultra-high energy region above 10 o the 19th power eV. The success of the Fly's Eye experiment provides impetus for continuing the development of larger detectors to make accessible even higher energies. However, due to the rapidly falling flux, a tenfold increase in observable energy would call for a hundredfold increase in the detecting area. But, the cost of expanding the Fly's Eye detecting area will approximately scale linearly with area. It is for these reasons that the authors have proposed a new approach to using the atmosphere as a scintillator; one which will require fewer photomultipliers, less hardware (thus being less extensive), yet will provide position and shower size information.

  3. Phenomenological characteristic of the electron component in gamma-quanta initiated showers

    NASA Technical Reports Server (NTRS)

    Nikolsky, S. I.; Stamenov, J. N.; Ushev, S. Z.

    1985-01-01

    The phenomenological characteristics of the electron component in showers initiated by primary gamma-quanta were analyzed on the basis of the Tien Shan experimental data. It is shown that the lateral distribution of the electrons ion gamma-quanta initiated showers can be described with NKG - function with age parameters bar S equals 0, 76 plus or minus 0, 02, different from the same parameter for normal showers with the same size bar S equals 0, 85 plus or minus 0, 01. The lateral distribution of the correspondent electron energy flux in gamma-quanta initiated showers is steeper as in normal cosmic ray showers.

  4. Status of air-shower measurements with sparse radio arrays

    NASA Astrophysics Data System (ADS)

    Schröder, Frank G.

    2017-03-01

    This proceeding gives a summary of the current status and open questions of the radio technique for cosmic-ray air showers, assuming that the reader is already familiar with the principles. It includes recent results of selected experiments not present at this conference, e.g., LOPES and TREND. Current radio arrays like AERA or Tunka-Rex have demonstrated that areas of several km2 can be instrumented for reasonable costs with antenna spacings of the order of 200m. For the energy of the primary particle such sparse antenna arrays can already compete in absolute accuracy with other precise techniques, like the detection of air-fluorescence or air-Cherenkov light. With further improvements in the antenna calibration, the radio detection might become even more accurate. For the atmospheric depth of the shower maximum, Xmax, currently only the dense array LOFAR features a precision similar to the fluorescence technique, but analysis methods for the radio measurement of Xmax are still under development. Moreover, the combination of radio and muon measurements is expected to increase the accuracy of the mass composition, and this around-the-clock recording is not limited to clear nights as are the light-detection methods. Consequently, radio antennas will be a valuable add-on for any air shower array targeting the energy range above 100 PeV.

  5. Extensive air showers, lightning, and thunderstorm ground enhancements

    NASA Astrophysics Data System (ADS)

    Chilingarian, A.; Hovsepyan, G.; Kozliner, L.

    2016-09-01

    For lightning research, we monitor particle fluxes from thunderclouds, the so-called thunderstorm ground enhancements (TGEs) initiated by runaway electrons, and extensive air showers (EASs) originating from high-energy protons or fully stripped nuclei that enter the Earth's atmosphere. We also monitor the near-surface electric field and atmospheric discharges using a network of electric field mills. The Aragats "electron accelerator" produced several TGEs and lightning events in the spring of 2015. Using 1-s time series, we investigated the relationship between lightning and particle fluxes. Lightning flashes often terminated the particle flux; in particular, during some TGEs, lightning events would terminate the particle flux thrice after successive recovery. It was postulated that a lightning terminates a particle flux mostly in the beginning of a TGE or in its decay phase; however, we observed two events (19 October 2013 and 20 April 2015) when the huge particle flux was terminated just at the peak of its development. We discuss the possibility of a huge EAS facilitating lightning leader to find its path to the ground.

  6. Construction of a cosmic ray air shower telescope

    NASA Technical Reports Server (NTRS)

    Ng, L. K.; Chan, S. K.

    1985-01-01

    The telescope under construction is mainly for the purpose of locating the arrival directions of energetic particles and quanta which generate air showers of sizes 10 to the 5th power to 10 to the 6th power. Both fast timing method and visual track method are incorporated in determining the arrival directions. The telescope is composed of four stations using scintillators and neon flash tubes as detectors. The system directional resolution is better than 1.5 deg.

  7. Acoustic detection of cosmic-ray air showers.

    PubMed

    Barrett, W L

    1978-11-17

    The signal strength, bandwidth, and detection range of acoustic pulses generated by cosmic-ray air showers striking a water surface are calculated. These signals are strong enough to be audible to a submerged swimmer. The phenomena may be useful for studying very-high-energy cosmic rays and may help answer the important question of whether the origin of cosmic rays is extragalactic or galactic.

  8. Results from the Puebla extensive air shower detector array

    NASA Astrophysics Data System (ADS)

    Salazar, H.; Martinez, O.; Moreno, E.; Cotzomi, J.; Villaseñor, L.; Saavedrac, O.

    2003-07-01

    We describe the design and operation of the first stage of the EAS-UAP extensive air shower array, as a detector of very high energy cosmic rays ( Eo > 10 14eV). The array is located at the Campus of Puebla University and consists of 18 liquid scintillator detectors, with an active surface of 1 m2 each and a detector spacing of 20 m in a square grid. In this report we discuss the stability and the calibration of the detector array, as derived from the 10 detectors in operation in the first stage. The main characteristics of the array allow us also to use it as an educational and training facility. First distributions of the arrival direction and the lateral shower srpead are also given.

  9. Constraints on hadronic models in extensive air showers with the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Espadanal, João

    2016-11-01

    Extensive air showers initiated by ultra-high energy cosmic rays are sensitive to the details of hadronic interactions models, so we present the main results obtained using the data of the Pierre Auger Observatory. The depth at which the maximum of the electromagnetic development takes place is the most sensitive parameter to infer the nature of the cosmic rays. However, the hadronic models cannot describe consistently the maximum and the muon measurements at energies higher than those reached at the LHC.

  10. Correlation of high energy muons with primary composition in extensive air shower

    NASA Technical Reports Server (NTRS)

    Chou, C.; Higashi, S.; Hiraoka, N.; Ozaki, S.; Sato, T.; Suwada, T.; Takahasi, T.; Umeda, H.

    1985-01-01

    An experimental investigation of high energy muons above 200 GeV in extensive air showers has been made for studying high energy interaction and primary composition of cosmic rays of energies in the range 10 to the 14th power approx. 10 to the 15th power eV. The muon energies are estimated from the burst sizes initiated by the muons in the rock, which are measured by four layers of proportional counters, each of area 5 x 2.6 sq m, placed at 30 m.w.e. deep, Funasaka tunnel vertically below the air shower array. These results are compared with Monte Carlo simulations based on the scaling model and the fireball model for two primary compositions, all proton and mixed.

  11. First detection of extensive air showers with the EEE experiment

    NASA Astrophysics Data System (ADS)

    Moro, R.

    2011-03-01

    The Extreme Energy Events (EEE) Project is devoted to the study of extremely high energy cosmic rays by means of an array of particle detectors distributed all over the Italian territory. Each element of the array (called telescope in the following) is installed in a High School, with the further goal to introduce students to particle and astroparticle physics, and consists of three Multigap Resistive Plate Chambers (MRPC), that have excellent time resolution and good tracking capability. In this paper the first results on the detection of extensive air showers by means of time coincidences between two telescopes are presented.

  12. Geomagnetic Field Effects on the Imaging Air Shower Cherenkov Technique

    NASA Astrophysics Data System (ADS)

    Commichau, S.C.; Biland, A.; Kranich, D.; de los Reyes, R.; Moralejo, A.; Sobczyńska, D.

    Imaging Air Cherenkov Telescopes (IACTs) detect the Cherenkov light flashes of Extended Air Showers (EAS) triggered by VHE gamma-rays impinging on the Earth's atmosphere. Due to the overwhelming background from hadron induced EAS, the discrimination of the rare gamma-like events is rather difficult, in particular at energies below 100 GeV. The influence of the Geomagnetic Field (GF) on the EAS development can further complicate this discrimination and, in addition, also systematically affect the gamma-efficiency and energy resolution of an IACT. Here we present the results from dedicated Monte Carlo (MC) simulations for the MAGIC telescope site, show the GF effects on real data as well as possible corrections for these effects.

  13. Radio detection of cosmic-ray air showers and high-energy neutrinos

    NASA Astrophysics Data System (ADS)

    Schröder, Frank G.

    2017-03-01

    In the last fifteen years radio detection made it back to the list of promising techniques for extensive air showers, firstly, due to the installation and successful operation of digital radio experiments and, secondly, due to the quantitative understanding of the radio emission from atmospheric particle cascades. The radio technique has an energy threshold of about 100 PeV, which coincides with the energy at which a transition from the highest-energy galactic sources to the even more energetic extragalactic cosmic rays is assumed. Thus, radio detectors are particularly useful to study the highest-energy galactic particles and ultra-high-energy extragalactic particles of all types. Recent measurements by various antenna arrays like LOPES, CODALEMA, AERA, LOFAR, Tunka-Rex, and others have shown that radio measurements can compete in precision with other established techniques, in particular for the arrival direction, the energy, and the position of the shower maximum, which is one of the best estimators for the composition of the primary cosmic rays. The scientific potential of the radio technique seems to be maximum in combination with particle detectors, because this combination of complementary detectors can significantly increase the total accuracy for air-shower measurements. This increase in accuracy is crucial for a better separation of different primary particles, like gamma-ray photons, neutrinos, or different types of nuclei, because showers initiated by these particles differ in average depth of the shower maximum and in the ratio between the amplitude of the radio signal and the number of muons. In addition to air-shower measurements, the radio technique can be used to measure particle cascades in dense media, which is a promising technique for detection of ultra-high-energy neutrinos. Several pioneering experiments like ARA, ARIANNA, and ANITA are currently searching for the radio emission by neutrino-induced particle cascades in ice. In the next years

  14. Ultra-High Energy Cosmic Rays: Composition, Early Air Shower Interactions, and Xmax Skewness

    NASA Astrophysics Data System (ADS)

    Stapleton, James

    The composition of Ultra-High Energy Cosmic Rays (UHECRs) is still not completely understood, and must be inferred from Extended Air Shower (EAS), particle cascades which they initiate upon entering the atmosphere. The atmospheric depth at which the shower contains the maximum number of particles ( Xmax) is the most composition-sensitive property of the air shower, but its interpretation is hindered by intrinsic statistical fluctuations in EAS development which cause distinct compositions to produce overlapping Xmax distributions as well as our limited knowledge at these energies of hadronic physics which strongly impacts the Xmax distribution's shape. These issues ultimately necessitate a variety of complementary approaches to interpreting UHECR composition from Xmax data. The current work advances these approaches by connecting X max skewness to the uncertainties above. The study of X max has historically focused only on the mean and standard deviation of its distribution, but skewness is shown here to be strongly related to both the statistical fluctuations in EAS development as well as the least-understood hadronic cross-sections in the air shower. This leads into a treatment of the Exponentially-Modified Gaussian (EMG) distribution, whose little-known properties make it very useful for Xmax analysis and for data analysis in general. A powerful method emerges which uses only descriptive statistics in a robust check for energy-dependent changes in UHECR mass or EAS development. The application of these analyses to X max data provides tantalizing clues concerning issues of critical importance, such as the relationship between Xmax and the 'ankle' break in the UHECR energy spectrum, or the inferred properties of the UHECR mass distribution and its strong dependence on hadronic model systematics.

  15. A generalized description of the signal size in extensive air shower detectors and its applications

    NASA Astrophysics Data System (ADS)

    Ave, M.; Engel, R.; Roth, M.; Schulz, A.

    2017-01-01

    The number as well as the energy and angular distributions of particles in extensive air showers (EAS) depend on the stage of the shower development and the distance to the shower axis. In this work we derive an analytic parameterization of the particle distributions at ground from air shower simulations convolved with the response of a surface detector array. Shower particles are classified into four components according to the shower component they belong to: the muonic component, the electromagnetic component stemming from muon interactions and muon decay, the purely electromagnetic component, and the newly introduced electromagnetic component from low-energy hadrons. Using this scheme, we will show that the total signal at ground level for different surface detectors can be described with minimal fluctuations with parameterizations depending on the primary energy, position of the shower maximum, and the overall number of muons in the shower. The simulation results for different combinations of primaries and hadronic interaction models are reproduced with an accuracy better than 5-10% in the range from 100 m to 2000 m from the shower core. This parameterization is then used as a Lateral Distribution ansatz to reconstruct showers in current EAS experiments. Since this ansatz depends on physical parameters, it opens the possibility to infer them from data.

  16. Interpretation of the cosmic-ray air shower signal in Askaryan radio detectors

    NASA Astrophysics Data System (ADS)

    de Vries, Krijn D.; Buitink, Stijn; van Eijndhoven, Nick; Meures, Thomas; O'Murchadha, Aongus; Scholten, Olaf

    2017-03-01

    We discuss the radio emission from a cosmic-ray air shower propagating in air before it hits an air-ice boundary after which it completes its propagation inside the ice. The in-air emission, the in-ice emission, as well as the transition radiation from the shower crossing the boundary is considered. We discuss the interpretation of the radio signal observed by an in-ice observer.

  17. Overview of MHz air shower radio experiments and results

    NASA Astrophysics Data System (ADS)

    Revenu, Benoît

    2013-05-01

    In this paper, I present a review of the main results obtained in the last 10 years in the field of radio-detection of cosmic-ray air showers in the MHz range. All results from all experiments cannot be reported here so that I will focus on the results more than on the experiments themselves. Modern experiments started in 2003 with CODALEMA and LOPES. In 2006, small-size autonomous prototypes setup were installed at the Pierre Auger Observatory site, to help the design of the Auger Engineering Radio Array (AERA). We will discuss the principal aspects of the radio data analysis and the determination of the primary cosmic ray characteristics: the arrival direction, the lateral distribution of the electric field, the correlation with the primary energy, the emission mechanisms and the sensitivity to the composition of the cosmic rays.

  18. Implications of Ultrahigh Energy Air Showers for Physics and Astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    The primary ultrahigh energy particles which produce giant extensive air showers in the Earth atmosphere present an intriguing mystery from two points of view: (1) How are the base particles produced with such astounding energies, eight orders of magnitude higher than those produced by the best man-made terrestrial accelerators? (2) Since they are most likely extragalactic in origin, how do they reach us from extragalactic distances without suffering the severe losses expected from interactions with the 2.7 K thermal cosmic background photons, the so called GZK effect? The answers to these questions may involve new physics: violations of special relativity, grand unification theories, and quantum gravity theories involving large extra dimensions. They may involve new astrophysical sources, "zevatrons". Or some heretofore totally unknown physics or astrophysics may hold the answer. I will discuss here the mysteries involving the production and extragalactic propagation of ultrahigh energy cosmic rays and some suggested possible solutions.

  19. Akeno 20 km (2) air shower array (Akeno Branch)

    NASA Technical Reports Server (NTRS)

    Teshima, M.; Ohoka, H.; Matsubara, Y.; Hara, T.; Hatano, Y.; Hayashida, N.; He, C. X.; Honda, M.; Ishikawa, F.; Kamata, K.

    1985-01-01

    As the first stage of the future huge array, the Akeno air shower array was expanded to about 20 sq. km. by adding 19 scintillation detectors of 2.25 sq m area outside the present 1 sq. km. Akeno array with a new data collection system. These detectors are spaced about 1km from each other and connected by two optical fiber cables. This array has been in partial operation from 8th, Sep. 1984 and full operation from 20th, Dec. 1984. 20 sq m muon stations are planned to be set with 2km separation and one of them is now under construction. The origin of the highest energy cosmic rays is studied.

  20. Initial simulation study on high-precision radio measurements of the depth of shower maximum with SKAI-low

    NASA Astrophysics Data System (ADS)

    Zilles, Anne; Buitink, Stijn; Huege, Tim

    2017-03-01

    As LOFAR has shown, using a dense array of radio antennas for detecting extensive air showers initiated by cosmic rays in the Earth's atmosphere makes it possible to measure the depth of shower maximum for individual showers with a statistical uncertainty less than 20g/cm2. This allows detailed studies of the mass composition in the energy region around 1017 eV where the transition from a Galactic to an Extragalactic origin could occur. Since SKA1-low will provide a much denser and very homogeneous antenna array with a large bandwidth of 50 - 350 MHz it is expected to reach an uncertainty on the Xmax reconstruction of less than 10g/cm2. We present first results of a simulation study with focus on the potential to reconstruct the depth of shower maximum for individual showers to be measured with SKA1-low. In addition, possible influences of various parameters such as the numbers of antennas included in the analysis or the considered frequency bandwidth will be discussed.

  1. A generalized description of the time dependent signals in extensive air shower detectors and its applications

    NASA Astrophysics Data System (ADS)

    Ave, M.; Roth, M.; Schulz, A.

    2017-02-01

    The expected signal in extensive air shower (EAS) detectors can be predicted with a 10% accuracy by a parameterization that depends on a set of global shower parameters: the energy, the depth of the electromagnetic shower maximum (Xmax) and the overall muon content. By classifying shower particles in four components (muonic, purely electromagnetic, electromagnetic stemming from muon interactions and decay and electromagnetic-from-low-energy hadrons), shower-to-shower fluctuations are minimized. We follow this scheme to propose a model to describe the arrival time distributions of secondary particles as measured with surface detectors in an EAS experiment. This model is then used to reconstruct Xmax in Monte Carlo data sets. As an example, we show that for the case of the Pierre Auger Observatory Xmax can be reconstructed with an accuracy of about 45 g/cm2 at 1019 eV.

  2. Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events

    DOE PAGES

    Aab, Alexander

    2015-03-09

    We present the first hybrid measurement of the average muon number in air showers at ultra-high energies, initiated by cosmic rays with zenith angles between 62° and 80° . Our measurement is based on 174 hybrid events recorded simultaneously with the Surface Detector array and the Fluorescence Detector of the Pierre Auger Observatory. The muon number for each shower is derived by scaling a simulated reference profile of the lateral muon density distribution at the ground until it fits the data. A 1019 eV shower with a zenith angle of 67°, which arrives at the Surface Detector array at anmore » altitude of 1450 m above sea level, contains on average (2.68 ± 0.04 ± 0.48 (sys.)) × 107 muons with energies larger than 0.3 GeV. Finally, the logarithmic gain d ln Nµ/d ln E of muons with increasing energy between 4 × 1018 eV and 5 × 1019 eV is measured to be (1.029 ± 0.024 ± 0.030 (sys.)).« less

  3. Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events

    SciTech Connect

    Aab, Alexander

    2015-03-09

    We present the first hybrid measurement of the average muon number in air showers at ultra-high energies, initiated by cosmic rays with zenith angles between 62° and 80° . Our measurement is based on 174 hybrid events recorded simultaneously with the Surface Detector array and the Fluorescence Detector of the Pierre Auger Observatory. The muon number for each shower is derived by scaling a simulated reference profile of the lateral muon density distribution at the ground until it fits the data. A 1019 eV shower with a zenith angle of 67°, which arrives at the Surface Detector array at an altitude of 1450 m above sea level, contains on average (2.68 ± 0.04 ± 0.48 (sys.)) × 107 muons with energies larger than 0.3 GeV. Finally, the logarithmic gain d ln Nµ/d ln E of muons with increasing energy between 4 × 1018 eV and 5 × 1019 eV is measured to be (1.029 ± 0.024 ± 0.030 (sys.)).

  4. Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    We present the first hybrid measurement of the average muon number in air showers at ultrahigh energies, initiated by cosmic rays with zenith angles between 62° and 80°. The measurement is based on 174 hybrid events recorded simultaneously with the surface detector array and the fluorescence detector of the Pierre Auger Observatory. The muon number for each shower is derived by scaling a simulated reference profile of the lateral muon density distribution at the ground until it fits the data. A 1019 eV shower with a zenith angle of 67°, which arrives at the surface detector array at an altitude of 1450 m above sea level, contains on average (2.68 ±0.04 ±0.48 (sys))×107 muons with energies larger than 0.3 GeV. The logarithmic gain d ln Nμ/d ln E of muons with increasing energy between 4 ×1018 eV and 5 ×1019 eV is measured to be (1.029 ±0.024 ±0.030 (sys)) .

  5. A Neutron Burst Associated with an Extensive Air Shower?

    NASA Astrophysics Data System (ADS)

    Alves, Mauro; Martin, Inacio; Shkevov, Rumen; Gusev, Anatoly; De Abreu, Alessandro

    2016-07-01

    A portable and compact system based on a He-3 tube (LND, USA; model 25311) with an area of approximately 250 cm² and is used to record neutron count rates at ground level in the energy range of 0.025 eV to 10 MeV, in São José dos Campos, SP, Brazil (23° 12' 45" S, 45° 52' 00" W; altitude, 660m). The detector, power supply, digitizer and other hardware are housed in an air-conditioned room. The detector power supply and digitizer are not connected to the main electricity network; a high-capacity 12-V battery is used to power the detector and digitizer. Neutron counts are accumulated at 1-minute intervals continuously. The data are stored in a PC for further analysis. In February 8, 2015, at 12 h 22 min (local time) during a period of fair weather with minimal cloud cover (< 1 okta) the neutron detector recorded a sharp (count rate = 27 neutrons/min) and brief (< 1 min) increase in the count rate. In the days before and after this event, the neutron count rate has oscillated between 0 and 3 neutrons/min. Since the occurrence of this event is not related with spurious signals, malfunctioning equipment, oscillations in the mains voltage, etc. we are led to believe that the sharp increase was caused by a physical source such as a an extensive air shower that occurred over the detector.

  6. Proton-air and proton-proton cross sections from air shower data

    NASA Technical Reports Server (NTRS)

    Linsley, J.

    1985-01-01

    Data on the fluctuations in depth of maximum development of cosmic ray air showers, corrected for the effects of mixed primary composition and shower development fluctuations, yield values of the inelastic proton-air cross section for laboratory energies in the range 10 to the 8th power to 10 to the 10th power GeV. From these values of proton-air cross section, corresponding values of the proton-proton total cross section are derived by means of Glauber theory and geometrical scaling. The resulting values of proton-proton cross section are inconsistent with a well known 1n(2)s extrapolation of ISR data which is consistent with SPS data; they indicate a less rapid rate of increase in the interval 540 sq root of s 100000 GeV.

  7. Measurement of horizontal air showers with the Auger Engineering Radio Array

    NASA Astrophysics Data System (ADS)

    Kambeitz, Olga

    2017-03-01

    The Auger Engineering Radio Array (AERA), at the Pierre Auger Observatory in Argentina, measures the radio emission of extensive air showers in the 30-80 MHz frequency range. AERA consists of more than 150 antenna stations distributed over 17 km2. Together with the Auger surface detector, the fluorescence detector and the underground muon detector (AMIGA), AERA is able to measure cosmic rays with energies above 1017 eV in a hybrid detection mode. AERA is optimized for the detection of air showers up to 60° zenith angle, however, using the reconstruction of horizontal air showers with the Auger surface array, very inclined showers can also be measured. In this contribution an analysis of the AERA data in the zenith angle range from 62° to 80° will be presented. CoREAS simulations predict radio emission footprints of several km2 for horizontal air showers, which are now confirmed by AERA measurements. This can lead to radio-based composition measurements and energy determination of horizontal showers in the future and the radio detection of neutrino induced showers is possible.

  8. Search for tachyons associated with extensive air showers in the ground level cosmic radiation

    NASA Technical Reports Server (NTRS)

    Masjed, H. F.; Ashton, F.

    1985-01-01

    Events detected in a shielded plastic scintillation counter occurring in the 26 microsec preceding the arrival of an extensive air shower at ground level with local electron density or = 20 m to the -2 power and the 240 microsec after its arrival have been studied. No significant excess of events (tachyons) arriving in the early time domain have been observed in a sample of 11,585 air shower triggers.

  9. Development of a 12 parabola observation system to detect Molecular Bremsstrahlung Radiation from air-showers

    NASA Astrophysics Data System (ADS)

    Yamamoto, T.; Ogio, S.; Akimune, H.; Fujii, T.; Sakurai, N.; Fukushima, M.; Sagawa, H.

    2013-05-01

    Two experiments for the detections of Molecular Bremsstrahlung Radiation (MBR) from air-shower are under development in West Japan. One of these systems consists of 12 parabola antennas. And the other one uses a 45 cm Broadcasting Satellite (BS) antenna in a scintillator array. Both experiments measure 12 GHz radio emission from air-showers. The setup and the status of these experiments will be reported.

  10. Circular polarization of radio emission from air showers in thunderstorm conditions

    NASA Astrophysics Data System (ADS)

    Trinh, T. N. G.; Scholten, O.; Bonardi, A.; Buitink, S.; Corstanje, A.; Ebert, U.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Mitra, P.; Mulrey, K.; Nelles, A.; Thoudam, S.; Rachen, J. P.; Rossetto, L.; Rutjes, C.; Schellart, P.; ter Veen, S.; Winchen, T.

    2017-03-01

    We present measured radio emission from cosmic-ray-induced air showers under thunderstorm conditions. We observe for these events large differences in intensity, linear polarization and circular polarization from the events measured under fair-weather conditions. This can be explained by the effects of atmospheric electric fields in thunderclouds. Therefore, measuring the intensity and polarization of radio emission from cosmic ray extensive air showers during thunderstorm conditions provides a new tool to probe the atmospheric electric fields present in thunderclouds.

  11. Energetic delayed hadrons in large air showers observed at 5200m above sea level

    NASA Technical Reports Server (NTRS)

    Kaneko, T.; Hagiwara, K.; Yoshii, H.; Martinic, N.; Siles, L.; Miranda, P.; Kakimoto, F.; Tsuchimoto, I.; Inoue, N.; Suga, K.

    1985-01-01

    Energetic delayed hadrons in air showers with electron sizes in the range 10 to the 6th power to 10 to the 9th power were studied by observing the delayed bursts produced in the shield of nine square meter scintillation detectors in the Chacaltaya air-shower array. The frequency of such delayed burst is presented as a function of electron size, core distance and sec theta.

  12. Probing Atmospheric Electric Fields in Thunderstorms through Radio Emission from Cosmic-Ray-Induced Air Showers.

    PubMed

    Schellart, P; Trinh, T N G; Buitink, S; Corstanje, A; Enriquez, J E; Falcke, H; Hörandel, J R; Nelles, A; Rachen, J P; Rossetto, L; Scholten, O; Ter Veen, S; Thoudam, S; Ebert, U; Koehn, C; Rutjes, C; Alexov, A; Anderson, J M; Avruch, I M; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brüggen, M; Butcher, H R; Ciardi, B; de Geus, E; de Vos, M; Duscha, S; Eislöffel, J; Fallows, R A; Frieswijk, W; Garrett, M A; Grießmeier, J; Gunst, A W; Heald, G; Hessels, J W T; Hoeft, M; Holties, H A; Juette, E; Kondratiev, V I; Kuniyoshi, M; Kuper, G; Mann, G; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Moldon, J; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H; Scaife, A M M; Schwarz, D J; Serylak, M; Smirnov, O; Steinmetz, M; Swinbank, J; Tagger, M; Tasse, C; Toribio, M C; van Weeren, R J; Vermeulen, R; Vocks, C; Wise, M W; Wucknitz, O; Zarka, P

    2015-04-24

    We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields.

  13. Atmospheric Effects on Cosmic Ray Air Showers Observed with HAWC

    NASA Astrophysics Data System (ADS)

    Young, Steven

    2014-01-01

    The High Altitude Water Cherenkov Gamma Ray detector (HAWC), currently under construction on the Sierra Negra volcano near Puebla, Mexico, can be used to study solar physics with its scaler data acquisition system. Increases in the scaler rates are used to observe GeV cosmic rays from solar flares while decreases in the rates show the heliospheric disturbances associated with coronal mass ejections. However, weather conditions and height-dependent state variables such as pressure and temperature affect the production of extensive particle air showers that can be detected by the scaler system. To see if these atmospheric effects can be removed, we obtained local weather data from the Global Data Assimilation System (GDAS) and the local weather station at HAWC. The scaler pulse rates were then correlated to the pressure and temperature. We present data from a Forbush decrease observed by HAWC following a significant coronal mass ejection in April 2013, and describe our efforts to remove atmospheric variations from the scaler counts. This work was partially supported by the National Science Foundation’s REU program through NSF Award AST-1004881 to the University of Wisconsin-Madison.

  14. Simulation of radio emission from air showers in atmospheric electric fields

    SciTech Connect

    Buitink, S.; Huege, T.; Falcke, H; Kuijpers, J.

    2010-02-25

    We study the effect of atmospheric electric fields on the radio pulse emitted by cos- mic ray air showers. Under fair weather conditions the dominant part of the radio emission is driven by the geomagnetic field. When the shower charges are accelerated and deflected in an electric field additional radiation is emitted. We simulate this effect with the Monte Carlo code REAS2, using CORSIKA-simulated showers as input. In both codes a routine has been implemented that treats the effect of the electric field on the shower particles. We find that the radio pulse is significantly altered in background fields of the order of ~100 V/cm and higher. Practically, this means that air showers passing through thunderstorms emit radio pulses that are not a reliable measure for the shower energy. Under other weather circumstances significant electric field effects are expected to occur rarely, but nimbostratus clouds can harbor fields that are large enough. In general, the contribution of the electric field to the radio pulse has polarization properties that are different from the geomagnetic pulse. In order to filter out radio pulses that have been affected by electric field effects, radio air shower experiments should keep weatherinformation and perform full polarization measurements of the radio signal.

  15. New method to measure the attenuation of hadrons in extensive air showers

    SciTech Connect

    Apel, W. D.; Badea, F.; Bekk, K.; Bozdog, H.; Daumiller, K.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Gils, H. J.; Haungs, A.; Heck, D.; Huege, T.; Isar, P. G.; Klages, H. O.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Nehls, S.; Oehlschlaeger, J.

    2009-07-15

    Extensive air showers are generated through interactions of high-energy cosmic rays impinging the Earth's atmosphere. A new method is described to infer the attenuation of hadrons in air showers. The numbers of electrons and muons, registered with the scintillator array of the KASCADE experiment, are used to estimate the energy of the shower inducing primary particle. A large hadron calorimeter is used to measure the hadronic energy reaching observation level. The ratio of energy reaching ground level to the energy of the primary particle is used to derive an attenuation length of hadrons in air showers. In the energy range from 10{sup 6} to 3x10{sup 7} GeV the attenuation length obtained increases from 170 to 210 g/cm{sup 2}. The experimental results are compared to predictions of simulations based on contemporary high-energy interaction models.

  16. LOPES — Recent Results and Open Questions on the Radio Detection of Air Showers

    NASA Astrophysics Data System (ADS)

    Schröder, F. G.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Fuchs, B.; Gemmeke, H.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Krömer, O.; Kuijpers, J.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Melissas, M.; Morello, C.; Oehlschläger, J.; Palmieri, N.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Rühle, C.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schoo, S.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Zabierowski, J.; Zensus, J. A.

    2015-08-01

    LOPES was a digital antenna array operating for approximately 10 years until spring 2013 at the Karlsruhe Institute of Technology (KIT). Triggered by the co-located KASCADE-Grande air-shower experiment, it measured the radio signal of around 1000 cosmic-ray air showers with energies E ≳ 1017 eV in an effective band of 43 - 74 MHz. Using the interferometric technique of cross-correlation beamforming, LOPES could reconstruct the shower direction with an accuracy < 0.7°, the shower energy with a precision < 20%, and the atmospheric depth of the shower maximum, Xmax, with a precision < 95g/cm2. In particular the reconstruction of the shower maximum suffers from significant measurement uncertainties due to the radio-loud environment of the site. This article summarizes our latest results on the reconstruction of the shower maximum, using two independent methods: the steepness of the hyperbolic radio wavefront and the slope of the lateral distribution of the radio amplitude. Moreover, we show vectorial measurements of the electric field with the tripole antennas of the latest LOPES setup. Finally, we discuss open questions as well as the potential impact of the lessons learned at LOPES for future antenna arrays.

  17. The influence of the atmospheric refractive index on radio Xmax measurements of air showers

    NASA Astrophysics Data System (ADS)

    Corstanje, Arthur; Buitink, Stijn; Bonardi, Antonio; Falcke, Heino; Hörandel, Jörg R.; Mitra, Pragati; Mulrey, Katie; Nelles, Anna; Rachen, Jörg Paul; Rossetto, Laura; Schellart, Pim; Scholten, Olaf; Thoudam, Satyendra; Trinh, Gia; ter Veen, Sander; Winchen, Tobias

    2017-03-01

    The refractive index of the atmosphere, which is n ≈ 1:0003 at sea level, varies with altitude and with local temperature, pressure and humidity. When performing radio measurements of air showers, natural variations in n will change the radio lateral intensity distribution, by changing the Cherenkov angle. Using CoREAS simulations, we have evaluated the systematic error on measurements of the shower maximum Xmax due to variations in n. It was found that a 10% increase in refractivity (n - 1) leads to an underestimation of Xmax between 8 and 22 g/cm2 for proton-induced showers at zenith angles from 15 to 45 degrees, respectively.

  18. Radio signals from extensive air showers with the energies E 0 ≥ 1019 eV according to data from the Yakutsk extensive air shower array

    NASA Astrophysics Data System (ADS)

    Knurenko, S. P.; Petrov, I. S.

    2016-09-01

    A radio instrument and results obtained from the measurements of the 32-MHz radio signal from particles of extensive air showers (EASs) with energies E 0 ≥ 1×1019 eV are reported in brief. The data were obtained at the Yakutsk EAS array in 1987-1989 (the first series of measurements) and in 2009-2014 (new series of measurements). The radio signal from EASs with energies above 1020eV was detected at the Yakutsk EAS array for the first time, including the shower with the record energy of 2×1020 eV for the Yakutsk EAS array.

  19. Measurement of the circular polarization in radio emission from extensive air showers confirms emission mechanisms

    NASA Astrophysics Data System (ADS)

    Scholten, O.; Trinh, T. N. G.; Bonardi, A.; Buitink, S.; Correa, P.; Corstanje, A.; Dorosti Hasankiadeh, Q.; Falcke, H.; Hörandel, J. R.; Mitra, P.; Mulrey, K.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Thoudam, S.; ter Veen, S.; de Vries, K. D.; Winchen, T.

    2016-11-01

    We report here on a novel analysis of the complete set of four Stokes parameters that uniquely determine the linear and/or circular polarization of the radio signal for an extensive air shower. The observed dependency of the circular polarization on azimuth angle and distance to the shower axis is a clear signature of the interfering contributions from two different radiation mechanisms, a main contribution due to a geomagnetically-induced transverse current and a secondary component due to the build-up of excess charge at the shower front. The data, as measured at LOFAR, agree very well with a calculation from first principles. This opens the possibility to use circular polarization as an investigative tool in the analysis of air shower structure, such as for the determination of atmospheric electric fields.

  20. Studies of Cosmic Ray Composition and Air Shower Structure with the Pierre Auger Observatory

    SciTech Connect

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the average depth of shower maximum and its fluctuations with the Pierre Auger Observatory; (2) Study of the nuclear mass composition of UHECR with the surface detectors of the Pierre Auger Observatory; (3) Comparison of data from the Pierre Auger Observatory with predictions from air shower simulations: testing models of hadronic interactions; (4) A Monte Carlo exploration of methods to determine the UHECR composition with the Pierre Auger Observatory; (5) The delay of the start-time measured with the Pierre Auger Observatory for inclined showers and a comparison of its variance with models; (6) UHE neutrino signatures in the surface detector of the Pierre Auger Observatory; and (7) The electromagnetic component of inclined air showers at the Pierre Auger Observatory.

  1. Reconstruction of air-shower parameters for large-scale radio detectors using the lateral distribution

    NASA Astrophysics Data System (ADS)

    Kostunin, D.; Bezyazeekov, P. A.; Hiller, R.; Schröder, F. G.; Lenok, V.; Levinson, E.

    2016-02-01

    We investigate features of the lateral distribution function (LDF) of the radio signal emitted by cosmic ray air-showers with primary energies Epr > 0.1 EeV and its connection to air-shower parameters such as energy and shower maximum using CoREAS simulations made for the configuration of the Tunka-Rex antenna array. Taking into account all significant contributions to the total radio emission, such as by the geomagnetic effect, the charge excess, and the atmospheric refraction we parameterize the radio LDF. This parameterization is two-dimensional and has several free parameters. The large number of free parameters is not suitable for experiments of sparse arrays operating at low SNR (signal-to-noise ratios). Thus, exploiting symmetries, we decrease the number of free parameters based on the shower geometry and reduce the LDF to a simple one-dimensional function. The remaining parameters can be fit with a small number of points, i.e. as few as the signal from three antennas above detection threshold. Finally, we present a method for the reconstruction of air-shower parameters, in particular, energy and Xmax (shower maximum), which can be reached with a theoretical accuracy of better than 15% and 30 g/cm2, respectively.

  2. The wavefront of the radio signal emitted by cosmic ray air showers

    SciTech Connect

    Apel, W.D.; Bekk, K.; Blümer, J.; Bozdog, H.; Daumiller, K.; Doll, P.; Engel, R.; Arteaga-Velázquez, J.C.; Bähren, L.; Falcke, H.; Bertaina, M.; Cantoni, E.; Chiavassa, A.; Pierro, F. Di; Biermann, P.L.; Brancus, I.M.; De Souza, V.; Fuchs, B.; Gemmeke, H.; Grupen, C.; and others

    2014-09-01

    Analyzing measurements of the LOPES antenna array together with corresponding CoREAS simulations for more than 300 measured events with energy above 10{sup 17} eV and zenith angles smaller than 45{sup o}, we find that the radio wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The simulations predict a slightly steeper wavefront towards East than towards West, but this asymmetry is negligible against the measurement uncertainties of LOPES. At axis distances ∼> 50 m, the wavefront can be approximated by a simple cone. According to the simulations, the cone angle is clearly correlated with the shower maximum. Thus, we confirm earlier predictions that arrival time measurements can be used to study the longitudinal shower development, but now using a realistic wavefront. Moreover, we show that the hyperbolic wavefront is compatible with our measurement, and we present several experimental indications that the cone angle is indeed sensitive to the shower development. Consequently, the wavefront can be used to statistically study the primary composition of ultra-high energy cosmic rays. At LOPES, the experimentally achieved precision for the shower maximum is limited by measurement uncertainties to approximately 140 g/c {sup 2}. But the simulations indicate that under better conditions this method might yield an accuracy for the atmospheric depth of the shower maximum, X{sub max}, better than 30 g/c {sup 2}. This would be competitive with the established air-fluorescence and air-Cherenkov techniques, where the radio technique offers the advantage of a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be used to reconstruct the shower geometry more accurately, which potentially allows a better reconstruction of all other shower parameters, too.

  3. Measurement of the Depth of Maximum of Extensive Air Showers above 1018eV

    NASA Astrophysics Data System (ADS)

    Abraham, J.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Anzalone, A.; Aramo, C.; Arganda, E.; Arisaka, K.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avila, G.; Bäcker, T.; Badagnani, D.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Barroso, S. L. C.; Baughman, B.; Bauleo, P.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; Benzvi, S.; Berat, C.; Bergmann, T.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; 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.; Busca, N. G.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Colombo, E.; 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.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Domenico, M.; de Donato, C.; de Jong, S. J.; de La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; de Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; Del Peral, L.; Deligny, O.; Della Selva, A.; Delle Fratte, C.; Dembinski, H.; di Giulio, C.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Duvernois, M. A.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferrero, A.; Fick, B.; Filevich, A.; Filipčič, A.; Fleck, I.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fröhlich, U.; Fulgione, W.; Gamarra, R. F.; Gambetta, S.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Garrido, X.; Gelmini, G.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Goggin, L. M.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gonçalves, P.; Gonzalez, D.; Gonzalez, J. G.; Góra, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hague, J. D.; Halenka, V.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Hrabovský, M.; Huege, T.; Hussain, M.; Iarlori, M.; Insolia, A.; Ionita, F.; Italiano, A.; Jiraskova, S.; Kadija, K.; Kaducak, M.; Kampert, K. H.; Karova, T.; Kasper, P.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapik, R.; Knapp, J.; Koang, D.-H.; Krieger, A.; Krömer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, K.; Kunka, N.; Kusenko, A.; La Rosa, G.; Lachaud, C.; Lago, B. L.; Lautridou, P.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Lee, J.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McEwen, M.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Meurer, C.; Mičanović, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafá, M.; Mueller, S.; Muller, M. A.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nhung, P. T.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parlati, S.; Parra, A.; Parrisius, J.; Parsons, R. D.; Pastor, S.; Paul, T.; Pavlidou, V.; Payet, K.; 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.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Redondo, A.; Revenu, B.; Rezende, F. A. S.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivière, C.; Rizi, V.; Robledo, C.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-D'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; 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.; Schroeder, F.; Schulte, S.; Schüssler, F.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Siffert, B. B.; Sigl, G.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Stasielak, J.; Stephan, M.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Tamashiro, A.; Tamburro, A.; Tapia, A.; Tarutina, T.; Taşcău, O.; Tcaciuc, R.; Tcherniakhovski, D.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Venters, T.; Verzi, V.; Videla, M.; Villaseñor, L.; Vorobiov, S.; Voyvodic, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Williams, C.; Winchen, T.; Winnick, M. G.; Wundheiler, B.; Yamamoto, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.; Pierre Auger Collaboration

    2010-03-01

    We describe the measurement of the depth of maximum, Xmax⁡, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 1018eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106-21+35)g/cm2/decade below 1018.24±0.05eV, and (24±3)g/cm2/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26g/cm2. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

  4. A phenomenological model of the muon density profile on the ground of very inclined air showers

    NASA Astrophysics Data System (ADS)

    Dembinski, H. P.; Billoir, P.; Deligny, O.; Hebbeker, T.

    2010-09-01

    Ultra-high energy cosmic rays generate extensive air showers in Earth's atmosphere. A standard approach to reconstruct the energy of an ultra-high energy cosmic rays is to sample the lateral profile of the particle density on the ground of the air shower with an array of surface detectors. For cosmic rays with large inclinations, this reconstruction is based on a model of the lateral profile of the muon density observed on the ground, which is fitted to the observed muon densities in individual surface detectors. The best models for this task are derived from detailed Monte-Carlo simulations of the air shower development. We present a phenomenological parametrization scheme which allows to derive a model of the average lateral profile of the muon density directly from a fit to a set of individual Monte-Carlo simulated air showers. The model reproduces the detailed simulations with a high precision. As an example, we generate a muon density model which is valid in the energy range 10 18 eV < E < 10 20 eV and the zenith angle range 60°<θ<90°. We will further demonstrate a way to speed up the simulation of such muon profiles by three orders of magnitude, if only the muons in the shower are of interest.

  5. The Air Microwave Yield (AMY) experiment to measure the GHz emission from air shower plasmas

    NASA Astrophysics Data System (ADS)

    Alvarez-Muñiz, J.; Bohacova, M.; Cataldi, G.; Coluccia, M. R.; Creti, P.; De Mitri, I.; Di Giulio, C.; Engel, R.; Facal San Luis, P.; Iarlori, M.; Martello, D.; Monasor, M.; Perrone, L.; Petrera, S.; Privitera, P.; Riegel, M.; Rizi, V.; Rodriguez Fernandez, G.; Salamida, F.; Salina, G.; Settimo, M.; Smida, R.; Verzi, V.; Werner, F.; Williams, C.

    2013-06-01

    The AMY experiment aims to measure the Microwave Bremsstrahlung Radiation (MBR) emitted by air-showers secondary electrons accelerating in collisions with neutral molecules of the atmosphere. The measurements are performed at the Beam Test Facility (BTF) of Frascati INFN National Laboratories and the final purpose is to characterize the process to be used in a next generation detectors of ultra-high energy cosmic rays (up to 1020eV). We describe the experimental set-up and the first test measurement performed in November 2011.

  6. Extensive Air Showers and Cosmic Ray Physics above 1017 eV

    NASA Astrophysics Data System (ADS)

    Bertaina, Mario

    2016-07-01

    Cosmic Rays above 1017 eV allow studying hadronic interactions at energies that can not be attained at accelerators yet. At the same time hadronic interaction models have to be applied to the cosmic-ray induced air-shower cascades in atmosphere to infer the nature of cosmic rays. The reliability of air-shower simulations has become the source of one of the largest systematic uncertainty in the interpretation of cosmic-ray data due to the uncertainties in modeling the hadronic interaction driving the air-shower development. This paper summarises in the first part the recent results on the cosmic ray energy spectrum, composition and anisotropy from the knee region to the GZK cutoff [1, 2] of the spectrum by means of ground-based experiments. Most of the information reported in this contribution is taken from [3-5]. Aspects interconnecting cosmic ray and particle physics are reviewed in the second part of the paper.

  7. Extensive Air Showers: High Energy Phenomena and Astrophysical Aspects - A Tutorial, Reference Manual and Data Book

    NASA Astrophysics Data System (ADS)

    Grieder, P. K. F.

    Extensive air showers are a very unique phenomenon. In the more than six decades since their discovery by Auger et al. we have learned a great deal about these extremely energetic events and gained deep insights into high-energy phenomena, particle physics and astrophysics. In this Tutorial, Reference Manual and Data Book Peter K. F. Grieder provides the reader with a comprehensive view of the phenomenology and facts of the various types of interactions and cascades, theoretical background, experimental methods, data evaluation and interpretation, and air shower simulation. He discusses astrophysical aspects of the primary radiation and addresses the questions that continue to puzzle researchers.

  8. Longitudinal development of extensive air showers: Hybrid code SENECA and full Monte Carlo

    NASA Astrophysics Data System (ADS)

    Ortiz, Jeferson A.; Medina-Tanco, Gustavo; de Souza, Vitor

    2005-06-01

    New experiments, exploring the ultra-high energy tail of the cosmic ray spectrum with unprecedented detail, are exerting a severe pressure on extensive air shower modelling. Detailed fast codes are in need in order to extract and understand the richness of information now available. Some hybrid simulation codes have been proposed recently to this effect (e.g., the combination of the traditional Monte Carlo scheme and system of cascade equations or pre-simulated air showers). In this context, we explore the potential of SENECA, an efficient hybrid tri-dimensional simulation code, as a valid practical alternative to full Monte Carlo simulations of extensive air showers generated by ultra-high energy cosmic rays. We extensively compare hybrid method with the traditional, but time consuming, full Monte Carlo code CORSIKA which is the de facto standard in the field. The hybrid scheme of the SENECA code is based on the simulation of each particle with the traditional Monte Carlo method at two steps of the shower development: the first step predicts the large fluctuations in the very first particle interactions at high energies while the second step provides a well detailed lateral distribution simulation of the final stages of the air shower. Both Monte Carlo simulation steps are connected by a cascade equation system which reproduces correctly the hadronic and electromagnetic longitudinal profile. We study the influence of this approach on the main longitudinal characteristics of proton, iron nucleus and gamma induced air showers and compare the predictions of the well known CORSIKA code using the QGSJET hadronic interaction model.

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

    NASA Technical Reports Server (NTRS)

    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.

  10. Extensive Air Shower Detector Array at the Universidad Autonoma de Puebla

    NASA Astrophysics Data System (ADS)

    Cotzomi, J.; Moreno, E.; Aguilar, S.; Palma, B.; Martinez, O.; Salazar, H.; Villasenor, L.

    2002-07-01

    We describe the operation of an Extensive Air Shower Array located at the campus of the FCFM-BUAP. The array consists of 8 liquid scintillation detectors with a surface of 1 m2 each and a detector spacing of 20 m in a square grid. The array was designed to measure the energy and arrival direction of primary particles that generate extensive air showers (EAS) in the region of 1013 eV - 1016 eV. The angular distribution measured with this array, Cos8(Theta) xSin(Theta), agrees very well with the literature. We also present the measured energies of a number of vertical showers in the range of 5 x1012 eV to 5 x1013 eV.

  11. Atmospheric profiles at the southern Pierre Auger Observatory and their relevance to air shower measurement

    SciTech Connect

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

    2005-07-01

    The dependence of atmospheric conditions on altitude and time have to be known at the site of an air shower experiment for accurate reconstruction of extensive air showers and their simulations. The height-profile of atmospheric depth is of particular interest as it enters directly into the reconstruction of longitudinal shower development and of the primary energy and mass of cosmic rays. For the southern part of the Auger Observatory, the atmosphere has been investigated in a number of campaigns with meteorological radio soundings and with continuous measurements of ground-based weather stations. Focusing on atmospheric depth and temperature profiles, temporal variations are described and monthly profiles are developed. Uncertainties of the monthly atmospheres that are currently applied in the Auger reconstruction are discussed.

  12. Detection of Extensive Cosmic Air Showers by Small Scintillation Detectors with Wavelength-Shifting Fibres

    ERIC Educational Resources Information Center

    Aiola, Salvatore; La Rocca, Paola; Riggi, Francesco; Riggi, Simone

    2012-01-01

    A set of three small scintillation detectors was employed to measure correlated events due to the passage of cosmic muons originating from extensive air showers. The coincidence rate between (any) two detectors was extracted as a function of their relative distance. The difference between the arrival times in three non-aligned detectors was used…

  13. Radio detection of air showers with the ARIANNA experiment on the Ross Ice Shelf

    NASA Astrophysics Data System (ADS)

    Barwick, S. W.; Besson, D. Z.; Burgman, A.; Chiem, E.; Hallgren, A.; Hanson, J. C.; Klein, S. R.; Kleinfelder, S. A.; Nelles, A.; Persichilli, C.; Phillips, S.; Prakash, T.; Reed, C.; Shively, S. R.; Tatar, J.; Unger, E.; Walker, J.; Yodh, G.

    2017-04-01

    The ARIANNA hexagonal radio array (HRA) is an experiment in its pilot phase designed to detect cosmogenic neutrinos of energies above 1016 eV. The most neutrino-like background stems from the radio emission of air showers. This article reports on dedicated efforts of simulating and detecting the signals of cosmic rays. A description of the fully radio self-triggered data-set, the properties of the detected air shower signals in the frequency range of 100-500 MHz and the consequences for neutrino detection are given. 38 air shower signals are identified by their distinct waveform characteristics, are in good agreement with simulations and their signals provide evidence that neutrino-induced radio signals will be distinguishable with high efficiency in ARIANNA. The cosmic ray flux at a mean energy of 6.5-1.0+1.2 ×1017 eV is measured to be 1.1-0.7+1.0 ×10-16 eV-1 km-2 sr-1 yr-1 and one five-fold coincident event is used to illustrate the capabilities of the ARIANNA detector to reconstruct arrival direction and energy of air showers.

  14. Full Monte-Carlo description of the Moscow State University Extensive Air Shower experiment

    NASA Astrophysics Data System (ADS)

    Fomin, Yu. A.; Kalmykov, N. N.; Karpikov, I. S.; Kulikov, G. V.; Kuznetsov, M. Yu.; Rubtsov, G. I.; Sulakov, V. P.; Troitsky, S. V.

    2016-08-01

    The Moscow State University Extensive Air Shower (EAS-MSU) array studied high-energy cosmic rays with primary energies ~ (1-500) PeV in the Northern hemisphere. The EAS-MSU data are being revisited following recently found indications to an excess of muonless showers, which may be interpreted as the first observation of cosmic gamma rays at ~ 100 PeV. In this paper, we present a complete Monte-Carlo model of the surface detector which results in a good agreement between data and simulations. The model allows us to study the performance of the detector and will be used to obtain physical results in further studies.

  15. Ultrahigh energy cosmic ray composition from surface air shower and underground muon measurements at Soudan 2

    NASA Astrophysics Data System (ADS)

    Longley, N. P.; Bode, C. R.; Border, P. M.; Courant, H.; Demuth, D. M.; Gray, R. N.; Johns, K.; Kasahara, S. M.; Lowe, M. J.; Marshak, M. L.; Miller, W. H.; Mualem, L.; Peterson, E. A.; Roback, D. M.; Ruddick, K.; Schmid, D. J.; Schub, M. H.; Shupe, M. A.; Vassiliev, V.; Villaume, G.; Werkema, S. J.; Ayres, D. S.; Fields, T. H.; Gallagher, H. M.; Goodman, M. C.; Lopez, F. V.; May, E. N.; Price, L. E.; Seidlein, R. V.; Thron, J. L.; Trost, H.-J.; Uretsky, J. L.; Allison, W. W.; Barr, G. D.; Brooks, C. B.; Cobb, J. H.; Giller, G. L.; Stassinakis, A.; Thomson, M. A.; West, N.; Wielgosz, U.; Alner, G. J.; Cockerill, D. J.; Cotton, R. J.; Garcia-Garcia, C.; Litchfield, P. J.; Pearce, G. F.; Ewen, B.; Kafka, T.; Kochocki, J.; Leeson, W.; Mann, W. A.; Milburn, R. H.; Napier, A.; Oliver, W.; Saitta, B.; Schneps, J.; Sundaralingam, N.; Barrett, W. L.

    1995-09-01

    The Soudan 2 experiment has performed time-coincident cosmic ray air shower and underground muon measurements. Comparisons to Monte Carlo predictions show that such measurements can make statistically significant tests of the primary composition in the knee region of the cosmic ray spectrum. The results do not support any significant increase in the average primary mass with energy in the range of ~104 TeV per nucleus. Some systematic uncertainties remain, however, particularly in the Monte Carlo modeling of the cosmic ray shower.

  16. Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J. D.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J. C.; Chudoba, J.; Clay, R. W.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; Dallier, R.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; del Peral, L.; Deligny, O.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; Dorofeev, A.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Fang, K.; Farrar, G. R.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Gallo, F.; García, B.; Garcia-Pinto, D.; Gate, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Glass, H.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Hasankiadeh, Q.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Johnsen, J. A.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Latronico, L.; Lauscher, M.; Lautridou, P.; Lebrun, P.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; López, R.; López Casado, A.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Mello, V. B. B.; Melo, D.; Menshikov, A.; Messina, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Müller, G.; Muller, M. A.; Müller, S.; Naranjo, I.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, H.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pekala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pepe, I. M.; Pereira, L. A. S.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Rosado, J.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sanabria Gomez, J. D.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sarmiento-Cano, C.; Sato, R.; Scarso, C.; Schauer, M.; Scherini, V.; Schieler, H.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stapleton, J.; Stasielak, J.; Strafella, F.; Stutz, A.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valbuena-Delgado, A.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yang, L.; Yapici, T.; Yelos, D.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.; Pierre Auger Collaboration

    2016-11-01

    Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (ECM=110 - 170 TeV ), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33 ±0.16 (1.61 ±0.21 ) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

  17. Muons in air showers at the Pierre Auger Observatory: Measurement of atmospheric production depth

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    The surface detector array of the Pierre Auger Observatory provides information about the longitudinal development of the muonic component of extensive air showers. Using the timing information from the flash analog-to-digital converter traces of surface detectors far from the shower core, it is possible to reconstruct a muon production depth distribution. We characterize the goodness of this reconstruction for zenith angles around 60° and different energies of the primary particle. From these distributions, we define Xmaxμ as the depth along the shower axis where the production of muons reaches maximum. We explore the potentiality of Xmaxμ as a useful observable to infer the mass composition of ultrahigh-energy cosmic rays. Likewise, we assess its ability to constrain hadronic interaction models.

  18. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    SciTech Connect

    collaboration, The Pierre Augur

    2014-08-01

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.

  19. Measurement of the muon content in air showers at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Veberič, Darko

    2016-07-01

    The muon content of extensive air showers produced by ultra-high energy cosmic rays is an observable sensitive to the composition of primary particles and to the properties of hadronic interactions governing the evolution of air-shower cascades. We present different methods for estimation of the number of muons at the ground and the muon production depth. These methods use measurements of the longitudinal, lateral, and temporal distribution of particles in air showers recorded by the detectors of the Pierre Auger Observatory. The results, obtained at about 140 TeV center-of-mass energy for proton primaries, are compared to the predictions of LHC-tuned hadronic-interaction models used in simulations with different primary masses. The models exhibit a deficitin the predicted muon content. The combination of these results with other independent mass composition analyses, such as those involving the depth of shower maximum observablemax, provide additional constraints on hadronic-interaction models for energies beyond the reach of the LHC.

  20. The effect of the atmospheric refractive index on the radio signal of extensive air showers

    NASA Astrophysics Data System (ADS)

    Corstanje, A.; Bonardi, A.; Buitink, S.; Falcke, H.; Hörandel, J. R.; Mitra, P.; Mulrey, K.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; ter Veen, S.; Thoudam, S.; Trinh, G.; Winchen, T.

    2017-03-01

    For the interpretation of measurements of radio emission from extensive air showers, an important systematic uncertainty arises from natural variations of the atmospheric refractive index n. At a given altitude, the refractivity N =106(n - 1) can have relative variations on the order of 10% depending on temperature, humidity, and air pressure. Typical corrections to be applied to N are about 4%. Using CoREAS simulations of radio emission from air showers, we have evaluated the effect of varying N on measurements of the depth of shower maximum Xmax. For an observation band of 30-80 MHz, a difference of 4% in refractivity gives rise to a systematic error in the inferred Xmax between 3.5 and 11 g/cm2, for proton showers with zenith angles ranging from 15 to 50°. At higher frequencies, from 120 to 250 MHz, the offset ranges from 10 to 22 g/cm2. These offsets were found to be proportional to the geometric distance to Xmax. We have compared the results to a simple model based on the Cherenkov angle. For the 120 - 250 MHz band, the model is in qualitative agreement with the simulations. In typical circumstances, we find a slight decrease in Xmax compared to the default refractivity treatment in CoREAS. While this is within commonly treated systematic uncertainties, accounting for it explicitly improves the accuracy of Xmax measurements.

  1. Prospects for a radio air-shower detector at the South Pole

    NASA Astrophysics Data System (ADS)

    Böser, Sebastian; ARA Collaboration, IceCube Collaboration

    2013-05-01

    IceCube is not only the largest neutrino telescope but also one of the world's most competitive instruments for studying cosmic rays in the PeV to EeV regime where the transition from galactic to extra-galactic sources should occur. It records air showers with the ground sampling stations of IceTop and the in-ice optical modules of IceCube. Further augmenting this observatory with an array of sensors in the 10-100MHz regime that observe the radio emission from air showers will yield complementary information on the shower development. Such a triple-technology observatory should significantly improve the understanding of cosmic rays and enhance many aspects of its physics reach. Here we present first results from two exploratory radio setups deployed at the South Pole. Noise measurements from data taken in two consecutive seasons show a very good agreement of the predicted and observed response of the antennas which were designed specifically for this purpose. The radio background is found to be highly dominated by galactic noise with a prominent absence of anthropogenic radio emitters in the frequency band from 25-300MHz. Motivated by the excellent suitability of the location, we present first performance studies of a proposed Radio Air-Shower Test Array (RASTA) using detailed MonteCarlo simulation and discuss the prospects for its installation.

  2. Comparison of Air Shower and Vest Auxiliary Cooling during Simulated Tank Operations in the Heat

    DTIC Science & Technology

    1983-04-01

    would suggest that the crews’ thermal comfort was greater during vest auxiliary cooling. Despite the fact that the environmental conditions were...effective use of the turbine bleed air than is provided by an air shower. The vest approach seems to improve the thermal comfort of these tank crew members...in an environment which normally would be thermally stressful. This improved thermal comfort from vest cooling is probably associated with the reduced

  3. Electrons, muons and hadrons in extensive air showers and how do they depend on nuclear interaction model, part 1

    NASA Technical Reports Server (NTRS)

    Wrotniak, J. A.; Yodh, G. B.

    1985-01-01

    Monte Carlo simulations of extensive air showers were performed using a couple of different nuclear interaction models and obtaining a variety of shower characteristics. The discussion of these shows that the sensitivity of observables to the primary mass spectrum is significantly stronger than to the interaction model, the latter being quite weak.

  4. Impact of atmospheric effects on the energy reconstruction of air showers observed by the surface detectors of the Pierre Auger Observatory

    DOE PAGES

    Aab, A.; Abreu, P.; Aglietta, M.; ...

    2017-02-07

    Atmospheric conditions, such as the pressure (P), temperature (T) or air density (more » $$\\rho \\propto P/T$$), affect the development of extended air showers initiated by energetic cosmic rays. We study the impact of the atmospheric variations on the reconstruction of air showers with data from the arrays of surface detectors of the Pierre Auger Observatory, considering separately the one with detector spacings of 1500 m and the one with 750 m spacing. We observe modulations in the event rates that are due to the influence of the air density and pressure variations on the measured signals, from which the energy estimators are obtained. Lastly, we show how the energy assignment can be corrected to account for such atmospheric effects.« less

  5. Impact of atmospheric effects on the energy reconstruction of air showers observed by the surface detectors of the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Aab, A.; Abreu, P.; Aglietta, M.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Balaceanu, A.; Barreira Luz, R. J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Chavez, A. G.; Chinellato, J. A.; Chudoba, J.; Clay, R. W.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; Deligny, O.; Di Giulio, C.; Di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fick, B.; Figueira, J. M.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Gaior, R.; García, B.; Garcia-Pinto, D.; Gaté, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Glass, H.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Hasankiadeh, Q.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Johnsen, J. A.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kemp, J.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Lauscher, M.; Lebrun, P.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; López, R.; López Casado, A.; Luce, Q.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Mariš, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melo, D.; Menshikov, A.; Messina, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Mockler, D.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Müller, A. L.; Müller, G.; Muller, M. A.; Müller, S.; Mussa, R.; Naranjo, I.; Nellen, L.; Neuser, J.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, H.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pȩkala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pereira, L. A. S.; Perlín, M.; Perrone, L.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Ramos-Pollan, R.; Rautenberg, J.; Ravignani, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rogozin, D.; Roncoroni, M. J.; Roth, M.; Roulet, E.; Rovero, A. C.; Ruehl, P.; Saffi, S. J.; Saftoiu, A.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sanabria Gomez, J. D.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sarmiento, C. A.; Sato, R.; Schauer, M.; Scherini, V.; Schieler, H.; Schimp, M.; Schmidt, D.; Scholten, O.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Silli, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stasielak, J.; Stassi, P.; Strafella, F.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Swain, J.; Szadkowski, Z.; Taboada, A.; Taborda, O. A.; Tapia, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Torralba Elipe, G.; Torres Machado, D.; Torri, M.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Vergara Quispe, I. D.; Verzi, V.; Vicha, J.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Yang, L.; Yelos, D.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.

    2017-02-01

    Atmospheric conditions, such as the pressure (P), temperature (T) or air density (ρ propto P/T), affect the development of extended air showers initiated by energetic cosmic rays. We study the impact of the atmospheric variations on the reconstruction of air showers with data from the arrays of surface detectors of the Pierre Auger Observatory, considering separately the one with detector spacings of 1500 m and the one with 750 m spacing. We observe modulations in the event rates that are due to the influence of the air density and pressure variations on the measured signals, from which the energy estimators are obtained. We show how the energy assignment can be corrected to account for such atmospheric effects.

  6. Accelerator Measurements of Magnetically Induced Radio Emission from Particle Cascades with Applications to Cosmic-Ray Air Showers.

    PubMed

    Belov, K; Mulrey, K; Romero-Wolf, A; Wissel, S A; Zilles, A; Bechtol, K; Borch, K; Chen, P; Clem, J; Gorham, P W; Hast, C; Huege, T; Hyneman, R; Jobe, K; Kuwatani, K; Lam, J; Liu, T C; Nam, J; Naudet, C; Nichol, R J; Rauch, B F; Rotter, B; Saltzberg, D; Schoorlemmer, H; Seckel, D; Strutt, B; Vieregg, A G; Williams, C

    2016-04-08

    For 50 years, cosmic-ray air showers have been detected by their radio emission. We present the first laboratory measurements that validate electrodynamics simulations used in air shower modeling. An experiment at SLAC provides a beam test of radio-frequency (rf) radiation from charged particle cascades in the presence of a magnetic field, a model system of a cosmic-ray air shower. This experiment provides a suite of controlled laboratory measurements to compare to particle-level simulations of rf emission, which are relied upon in ultrahigh-energy cosmic-ray air shower detection. We compare simulations to data for intensity, linearity with magnetic field, angular distribution, polarization, and spectral content. In particular, we confirm modern predictions that the magnetically induced emission in a dielectric forms a cone that peaks at the Cherenkov angle and show that the simulations reproduce the data within systematic uncertainties.

  7. Accelerator Measurements of Magnetically Induced Radio Emission from Particle Cascades with Applications to Cosmic-Ray Air Showers

    NASA Astrophysics Data System (ADS)

    Belov, K.; Mulrey, K.; Romero-Wolf, A.; Wissel, S. A.; Zilles, A.; Bechtol, K.; Borch, K.; Chen, P.; Clem, J.; Gorham, P. W.; Hast, C.; Huege, T.; Hyneman, R.; Jobe, K.; Kuwatani, K.; Lam, J.; Liu, T. C.; Nam, J.; Naudet, C.; Nichol, R. J.; Rauch, B. F.; Rotter, B.; Saltzberg, D.; Schoorlemmer, H.; Seckel, D.; Strutt, B.; Vieregg, A. G.; Williams, C.; T-510 Collaboration

    2016-04-01

    For 50 years, cosmic-ray air showers have been detected by their radio emission. We present the first laboratory measurements that validate electrodynamics simulations used in air shower modeling. An experiment at SLAC provides a beam test of radio-frequency (rf) radiation from charged particle cascades in the presence of a magnetic field, a model system of a cosmic-ray air shower. This experiment provides a suite of controlled laboratory measurements to compare to particle-level simulations of rf emission, which are relied upon in ultrahigh-energy cosmic-ray air shower detection. We compare simulations to data for intensity, linearity with magnetic field, angular distribution, polarization, and spectral content. In particular, we confirm modern predictions that the magnetically induced emission in a dielectric forms a cone that peaks at the Cherenkov angle and show that the simulations reproduce the data within systematic uncertainties.

  8. The Roland Maze Project school-based extensive air shower network

    NASA Astrophysics Data System (ADS)

    Feder, J.; Jȩdrzejczak, K.; Karczmarczyk, J.; Lewandowski, R.; Swarzyński, J.; Szabelska, B.; Szabelski, J.; Wibig, T.

    2006-01-01

    We plan to construct the large area network of extensive air shower detectors placed on the roofs of high school buildings in the city of Łódź. Detection points will be connected by INTERNET to the central server and their work will be synchronized by GPS. The main scientific goal of the project are studies of ultra high energy cosmic rays. Using existing town infrastructure (INTERNET, power supply, etc.) will significantly reduce the cost of the experiment. Engaging high school students in the research program should significantly increase their knowledge of science and modern technologies, and can be a very efficient way of science popularisation. We performed simulations of the projected network capabilities of registering Extensive Air Showers and reconstructing energies of primary particles. Results of the simulations and the current status of project realisation will be presented.

  9. Time correlation measurements from extensive air showers detected by the EEE telescopes

    NASA Astrophysics Data System (ADS)

    Abbrescia, M.; Agocs, A.; Aiola, S.; Antolini, R.; Avanzini, C.; Baldini Ferroli, R.; Bencivenni, G.; Bossini, E.; Bressan, E.; Chiavassa, A.; Cicalò, C.; Cifarelli, L.; Coccia, E.; De Gruttola, D.; De Pasquale, S.; Di Giovanni, A.; D'Incecco, M.; Dreucci, M.; Fabbri, F. L.; Frolov, V.; Garbini, M.; Gemme, G.; Gnesi, I.; Gustavino, C.; Hatzifotiadou, D.; La Rocca, P.; Li, S.; Librizzi, F.; Maggiora, A.; Massai, M.; Miozzi, S.; Panareo, M.; Paoletti, R.; Perasso, L.; Pilo, F.; Piragino, G.; Regano, A.; Riggi, F.; Righini, G. C.; Sartorelli, G.; Scapparone, E.; Scribano, A.; Selvi, M.; Serci, S.; Siddi, E.; Spandre, G.; Squarcia, S.; Taiuti, M.; Tosello, F.; Votano, L.; Williams, M. C. S.; Yanez, G.; Zichichi, A.; Zouyevski, R.

    2013-12-01

    Time correlated events due to cosmic muons from extensive air showers have been detected by means of telescope pairs of the EEE (Extreme Energy Events) Project array. The coincidence rate, properly normalized for detector acceptance, efficiency and altitude location, has been extracted as a function of the relative distance between the telescopes. The results have been also compared with additional measurements carried out by small scintillator detectors at various distances.

  10. Air Shower Events of High-Energy Cosmic Rays Measured at Seoul, South Korea

    NASA Astrophysics Data System (ADS)

    Cho, Wooram; Shin, Jae-Ik; Kim, Hongki; Lee, Seulgi; Lim, Sunin; Nam, Sinwoo; Yang, Jongmann; Cheon, Byunggu; Bang, Hyungchan; Kwon, Youngjoon

    2011-09-01

    The COsmic ray Research and Education Array (COREA) collaboration has installed an array of six detector stations at two high schools in and near Seoul, Korea for measurement of air-shower events from high-energy cosmic rays. Three stations are installed at each site, where each station consists of four plastic scintillation detectors covering an area of 2m2. In this presentation, we report the currenst status of the COREA project, describing the experimental equipment and measurement of coincident events.

  11. A likelihood method to cross-calibrate air-shower detectors

    NASA Astrophysics Data System (ADS)

    Dembinski, Hans Peter; Kégl, Balázs; Mariş, Ioana C.; Roth, Markus; Veberič, Darko

    2016-01-01

    We present a detailed statistical treatment of the energy calibration of hybrid air-shower detectors, which combine a surface detector array and a fluorescence detector, to obtain an unbiased estimate of the calibration curve. The special features of calibration data from air showers prevent unbiased results, if a standard least-squares fit is applied to the problem. We develop a general maximum-likelihood approach, based on the detailed statistical model, to solve the problem. Our approach was developed for the Pierre Auger Observatory, but the applied principles are general and can be transferred to other air-shower experiments, even to the cross-calibration of other observables. Since our general likelihood function is expensive to compute, we derive two approximations with significantly smaller computational cost. In the recent years both have been used to calibrate data of the Pierre Auger Observatory. We demonstrate that these approximations introduce negligible bias when they are applied to simulated toy experiments, which mimic realistic experimental conditions.

  12. A study of radio frequency spectrum emitted by high energy air showers with LOFAR

    NASA Astrophysics Data System (ADS)

    Rossetto, Laura; Bonardi, Antonio; Buitink, Stijn; Corstanje, Arthur; Enriquez, J. Emilio; Falcke, Heino; Hörandel, Jörg R.; Mitra, Pragati; Mulrey, Katie; Nelles, Anna; Rachen, Jörg P.; Schellart, Pim; Scholten, Olaf; Thoudam, Satyendra; Trinh, Gia; ter Veen, Sander; Winchen, Tobias

    2017-03-01

    The high number density of radio antennas at the LOFAR core in Northern Netherlands allows to detect radio signals emitted by cosmic ray induced air showers, and to characterize the geometry of the observed cascade in a detailed way. We present here a study of the radio frequency spectrum in the 30 - 80 MHz regime, and its correlation with some geometrical parameters of the extensive air shower. An important goal of this study is to find a correlation between the frequency spectrum and the primary particle type. Preliminary results on how the frequency spectrum changes as function of distance to the shower axis, and as function of primary particles mass composition are shown. The final aim of this study is to find a method to infer information of primary cosmic rays in an independent way from the well-established fluorescence and surface detector techniques, in view of affirming the radio detection technique as reliable method for the study of high energy cosmic rays.

  13. A Search for VHE Emission from GRBs using the HAWC Observatory Air Shower Data

    NASA Astrophysics Data System (ADS)

    Sparks Woodle, Kathryne

    2014-03-01

    At an altitude of 4100 m near the peak of Sierra Negra in Mexico, the High Altitude Water Cherenkov Observatory (HAWC) is a second generation water Cherenkov detector that primarily looks for very high-energy gamma-rays from the galaxy and beyond. Due to its wide field of view (~2 sr) and high duty cycle, this extensive air shower detector can observe the beginning of the prompt phase of GRBs occurring overhead. HAWC is sensitive to showers in the sub-TeV to TeV energy range and will be able to help constrain the shape and cutoff of high-energy GRB spectra, especially in conjunction with observations from other detectors such as Fermi. With the design improvement and higher elevation than its predecessor Milagro, HAWC will be almost two orders of magnitude more sensitive to GRBs at 100 GeV when complete. Existing instruments identify about 5 GRBs within HAWC's field of view per month. The detector has been operated throughout construction, and we will present a search for high-energy emission from GRBs, triggered by existing instruments, using HAWC directional air shower data.

  14. Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory.

    PubMed

    Aab, A; Abreu, P; Aglietta, M; Ahn, E J; Al Samarai, I; Albuquerque, I F M; Allekotte, I; Allen, J D; Allison, P; Almela, A; Alvarez Castillo, J; Alvarez-Muñiz, J; Ambrosio, M; Anastasi, G A; Anchordoqui, L; Andrada, B; Andringa, S; Aramo, C; Arqueros, F; Arsene, N; Asorey, H; Assis, P; Aublin, J; Avila, G; Badescu, A M; Baus, C; Beatty, J J; Becker, K H; Bellido, J A; Berat, C; Bertaina, M E; Bertou, X; Biermann, P L; Billoir, P; Biteau, J; Blaess, S G; Blanco, A; Blazek, J; Bleve, C; Blümer, H; Boháčová, M; Boncioli, D; Bonifazi, C; Borodai, N; Botti, A M; Brack, J; Brancus, I; Bretz, T; Bridgeman, A; Briechle, F L; Buchholz, P; Bueno, A; Buitink, S; Buscemi, M; Caballero-Mora, K S; Caccianiga, B; Caccianiga, L; Cancio, A; Canfora, F; Caramete, L; Caruso, R; Castellina, A; Cataldi, G; Cazon, L; Cester, R; Chavez, A G; Chiavassa, A; Chinellato, J A; Chirinos Diaz, J C; Chudoba, J; Clay, R W; Colalillo, R; Coleman, A; Collica, L; Coluccia, M R; Conceição, R; Contreras, F; Cooper, M J; Coutu, S; Covault, C E; Cronin, J; Dallier, R; D'Amico, S; Daniel, B; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; de Jong, S J; De Mauro, G; de Mello Neto, J R T; De Mitri, I; de Oliveira, J; de Souza, V; Debatin, J; Del Peral, L; Deligny, O; Dhital, N; Di Giulio, C; Di Matteo, A; Díaz Castro, M L; Diogo, F; Dobrigkeit, C; D'Olivo, J C; Dorofeev, A; Dos Anjos, R C; Dova, M T; Dundovic, A; Ebr, J; Engel, R; Erdmann, M; Erfani, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Falcke, H; Fang, K; Farrar, G R; Fauth, A C; Fazzini, N; Ferguson, A P; Fick, B; Figueira, J M; Filevich, A; Filipčič, A; Fratu, O; Freire, M M; Fujii, T; Fuster, A; Gallo, F; García, B; Garcia-Pinto, D; Gate, F; Gemmeke, H; Gherghel-Lascu, A; Ghia, P L; Giaccari, U; Giammarchi, M; Giller, M; Głas, D; Glaser, C; Glass, H; Golup, G; Gómez Berisso, M; Gómez Vitale, P F; González, N; Gookin, B; Gordon, J; Gorgi, A; Gorham, P; Gouffon, P; Griffith, N; Grillo, A F; Grubb, T D; Guarino, F; Guedes, G P; Hampel, M R; Hansen, P; Harari, D; Harrison, T A; Harton, J L; Hasankiadeh, Q; Haungs, A; Hebbeker, T; Heck, D; Heimann, P; Herve, A E; Hill, G C; Hojvat, C; Hollon, N; Holt, E; Homola, P; Hörandel, J R; Horvath, P; Hrabovský, M; Huege, T; Hulsman, J; Insolia, A; Isar, P G; Jandt, I; Jansen, S; Jarne, C; Johnsen, J A; Josebachuili, M; Kääpä, A; Kambeitz, O; Kampert, K H; Kasper, P; Katkov, I; Keilhauer, B; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Krause, R; Krohm, N; Kuempel, D; Kukec Mezek, G; Kunka, N; Kuotb Awad, A; LaHurd, D; Latronico, L; Lauscher, M; Lautridou, P; Lebrun, P; Legumina, R; Leigui de Oliveira, M A; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; Lopes, L; López, R; López Casado, A; Lucero, A; Malacari, M; Mallamaci, M; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, V; Mariş, I C; Marsella, G; Martello, D; Martinez, H; Martínez Bravo, O; Masías Meza, J J; Mathes, H J; Mathys, S; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mayotte, E; Mazur, P O; Medina, C; Medina-Tanco, G; Mello, V B B; Melo, D; Menshikov, A; Messina, S; Micheletti, M I; Middendorf, L; Minaya, I A; Miramonti, L; Mitrica, B; Molina-Bueno, L; Mollerach, S; Montanet, F; Morello, C; Mostafá, M; Moura, C A; Müller, G; Muller, M A; Müller, S; Naranjo, I; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nguyen, P H; Niculescu-Oglinzanu, M; Niechciol, M; Niemietz, L; Niggemann, T; Nitz, D; Nosek, D; Novotny, V; Nožka, H; Núñez, L A; Ochilo, L; Oikonomou, F; Olinto, A; Pakk Selmi-Dei, D; Palatka, M; Pallotta, J; Papenbreer, P; Parente, G; Parra, A; Paul, T; Pech, M; Pedreira, F; Pękala, J; Pelayo, R; Peña-Rodriguez, J; Pepe, I M; Pereira, L A S; Perrone, L; Petermann, E; Peters, C; Petrera, S; Phuntsok, J; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Plum, M; Porowski, C; Prado, R R; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Quinn, S; Rautenberg, J; Ravel, O; Ravignani, D; Revenu, B; Ridky, J; Risse, M; Ristori, P; Rizi, V; Rodrigues de Carvalho, W; Rodriguez Rojo, J; Rodríguez-Frías, M D; Rogozin, D; Rosado, J; Roth, M; Roulet, E; Rovero, A C; Saffi, S J; Saftoiu, A; Salazar, H; Saleh, A; Salesa Greus, F; Salina, G; Sanabria Gomez, J D; Sánchez, F; Sanchez-Lucas, P; Santos, E M; Santos, E; Sarazin, F; Sarkar, B; Sarmento, R; Sarmiento-Cano, C; Sato, R; Scarso, C; Schauer, M; Scherini, V; Schieler, H; Schmidt, D; Scholten, O; Schoorlemmer, H; Schovánek, P; Schröder, F G; Schulz, A; Schulz, J; Schumacher, J; Sciutto, S J; Segreto, A; Settimo, M; Shadkam, A; Shellard, R C; Sigl, G; Sima, O; Śmiałkowski, A; Šmída, R; Snow, G R; Sommers, P; Sonntag, S; Sorokin, J; Squartini, R; Stanca, D; Stanič, S; Stapleton, J; Stasielak, J; Strafella, F; Stutz, A; Suarez, F; Suarez Durán, M; Sudholz, T; Suomijärvi, T; Supanitsky, A D; Sutherland, M S; Swain, J; Szadkowski, Z; Taborda, O A; Tapia, A; Tepe, A; Theodoro, V M; Timmermans, C; Todero Peixoto, C J; Tomankova, L; Tomé, B; Tonachini, A; Torralba Elipe, G; Torres Machado, D; Travnicek, P; Trini, M; Ulrich, R; Unger, M; Urban, M; Valbuena-Delgado, A; Valdés Galicia, J F; Valiño, I; Valore, L; van Aar, G; van Bodegom, P; van den Berg, A M; van Vliet, A; Varela, E; Vargas Cárdenas, B; Varner, G; Vázquez, J R; Vázquez, R A; Veberič, D; Verzi, V; Vicha, J; Videla, M; Villaseñor, L; Vorobiov, S; Wahlberg, H; Wainberg, O; Walz, D; Watson, A A; Weber, M; Weindl, A; Wiencke, L; Wilczyński, H; Winchen, T; Wittkowski, D; Wundheiler, B; Wykes, S; Yang, L; Yapici, T; Yelos, D; Zas, E; Zavrtanik, D; Zavrtanik, M; Zepeda, A; Zimmermann, B; Ziolkowski, M; Zong, Z; Zuccarello, F

    2016-11-04

    Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (E_{CM}=110-170  TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

  15. Testing hadronic interactions at ultrahigh energies with air showers measured by the Pierre Auger Observatory

    SciTech Connect

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J. D.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J. C.; Chudoba, J.; Clay, R. W.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; Dallier, R.; D’Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; del Peral, L.; Deligny, O.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D’Olivo, J. C.; Dorofeev, A.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Fang, K.; Farrar, G. R.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Gallo, F.; García, B.; Garcia-Pinto, D.; Gate, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Glass, H.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Hasankiadeh, Q.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Johnsen, J. A.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Latronico, L.; Lauscher, M.; Lautridou, P.; Lebrun, P.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; López, R.; López Casado, A.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Mello, V. B. B.; Melo, D.; Menshikov, A.; Messina, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Müller, G.; Muller, M. A.; Müller, S.; Naranjo, I.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, H.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pękala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pepe, I. M.; Pereira, L. A. S.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Rosado, J.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sanabria Gomez, J. D.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sarmiento-Cano, C.; Sato, R.; Scarso, C.; Schauer, M.; Scherini, V.; Schieler, H.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stapleton, J.; Stasielak, J.; Strafella, F.; Stutz, A.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valbuena-Delgado, A.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yang, L.; Yapici, T.; Yelos, D.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.

    2016-10-31

    Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6–16 EeV (ECM = 110–170 TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. As a result, the average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

  16. Testing hadronic interactions at ultrahigh energies with air showers measured by the Pierre Auger Observatory

    DOE PAGES

    Aab, A.; Abreu, P.; Aglietta, M.; ...

    2016-10-31

    Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6–16 EeV (ECM = 110–170 TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. As a result, the average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

  17. Development of Yangbajing air shower core detector for a new EAS hybrid experiment

    NASA Astrophysics Data System (ADS)

    Liu, Jin-Sheng; Huang, Jing; Chen, Ding; Zhang, Ying; Zhai, Liu-Ming; Chen, Xu; Hu, Xiao-Bin; Lin, Yu-Hui; Zhang, Xue-Yao; Feng, Cun-Feng; Jia, Huan-Yu; Zhou, Xun-Xiu; Danzengluobu; Chen, Tian-Lu; Li, Hai-Jin; Liu, Mao-Yuan; Yuan, Ai-Fang

    2015-08-01

    Aiming at the observation of cosmic-ray chemical composition in the “knee” energy region, we have been developing a new type of air-shower core detector (YAC, Yangbajing Air shower Core detector array) to be set up at Yangbajing (90.522° E, 30.102° N, 4300 m above sea level, atmospheric depth: 606 g/m2) in Tibet, China. YAC works together with the Tibet air-shower array (Tibet-III) and an underground water Cherenkov muon detector array (MD) as a hybrid experiment. Each YAC detector unit consists of lead plates of 3.5 cm thickness and a scintillation counter which detects the burst size induced by high energy particles in the air-shower cores. The burst size can be measured from 1 MIP (Minimum Ionization Particle) to 106 MIPs. The first phase of this experiment, named “YAC- I”, consists of 16 YAC detectors each with a size of 40 cm×50 cm and distributed in a grid with an effective area of 10 m2. YAC- I is used to check hadronic interaction models. The second phase of the experiment, called “YAC- II”, consists of 124 YAC detectors with coverage of about 500 m2. The inner 100 detectors of 80 cm×50 cm each are deployed in a 10×10 matrix with a 1.9 m separation; the outer 24 detectors of 100 cm×50 cm each are distributed around these to reject non-core events whose shower cores are far from the YAC- II array. YAC- II is used to study the primary cosmic-ray composition, in particular, to obtain the energy spectra of protons, helium and iron nuclei between 5×1013 eV and 1016 eV, covering the “knee” and also connected with direct observations at energies around 100 TeV. We present the design and performance of YAC- II in this paper. Supported by grants from the National Natural Science Foundation of China (11078002, 11275212, 11165013), the Chinese Academy of Sciences (H9291450S3, Y4293211S5) and the Knowledge Innovation Fund of Institute of High Energy Physics (IHEP), China (H95451D0U2, H8515530U1)

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

    NASA Technical Reports Server (NTRS)

    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.

  19. Selection and reconstruction of very inclined air showers with the Surface Detector of the Pierre Auger Observatory

    SciTech Connect

    Newton, D.; /Santiago de Compostela U.

    2007-06-01

    The water-Cherenkov tanks of the Pierre Auger Observatory can detect particles at all zenith angles and are therefore well-suited for the study of inclined and horizontal air showers (60 degrees < {theta} < 90 degrees). Such showers are characterized by a dominance of the muonic component at ground, and by a very elongated and asymmetrical footprint which can even exhibit a lobular structure due to the bending action of the geomagnetic field. Dedicated algorithms for the selection and reconstruction of such events, as well as the corresponding acceptance calculation, have been set up on basis of muon maps obtained from shower simulations.

  20. Radio measurements of the energy and the depth of the shower maximum of cosmic-ray air showers by Tunka-Rex

    SciTech Connect

    Bezyazeekov, P.A.; Budnev, N.M.; Gress, O.A.; Kazarina, Y.; Konstantinov, E.N.; Mirgazov, R.R.; Monkhoev, R.; Pakhorukov, A.; Pankov, L.; Haungs, A.; Hiller, R.; Huege, T.; Kostunin, D.; Kleifges, M.; Krömer, O.; Korosteleva, E.E.; Kuzmichev, L.A.; Lubsandorzhiev, N.; Prosin, V.V.; Rubtsov, G.I.; and others

    2016-01-01

    We reconstructed the energy and the position of the shower maximum of air showers with energies E ∼> 100 PeV applying a method using radio measurements performed with Tunka-Rex. An event-to-event comparison to air-Cherenkov measurements of the same air showers with the Tunka-133 photomultiplier array confirms that the radio reconstruction works reliably. The Tunka-Rex reconstruction methods and absolute scales have been tuned on CoREAS simulations and yield energy and X{sub max} values consistent with the Tunka-133 measurements. The results of two independent measurement seasons agree within statistical uncertainties, which gives additional confidence in the radio reconstruction. The energy precision of Tunka-Rex is comparable to the Tunka-133 precision of 15%, and exhibits a 20% uncertainty on the absolute scale dominated by the amplitude calibration of the antennas. For X{sub max}, this is the first direct experimental correlation of radio measurements with a different, established method. At the moment, the X{sub max} resolution of Tunka-Rex is approximately 40 g/cm{sup 2}. This resolution can probably be improved by deploying additional antennas and by further development of the reconstruction methods, since the present analysis does not yet reveal any principle limitations.

  1. Studying depth of shower maximum using variable interaction length

    NASA Astrophysics Data System (ADS)

    Dehghani, Hojat; Fatemi, Seyed Jalil; Davoudifar, Pantea

    2017-04-01

    Due to the high energy interactions of cosmic ray particles, progressive showers of secondary particles initiate in the atmosphere. Several models are suggested to describe the longitudinal development of extensive air showers, for example the Heitler model. The Heitler model also is written for hadronic showers. Anyhow, the predicted values of X_{max} may differ significantly with the values from detailed simulations by up to about 100 (g/cm2). In the present work, the mean depth of shower maximum is calculated using a variable interaction length. New equations for X_{max} in the electromagnetic and hadronic showers have been obtained.

  2. Constraining Microwave Emission from Extensive Air Showers via the MIDAS Experiment

    NASA Astrophysics Data System (ADS)

    Richardson, Matthew; Privitera, Paolo

    2017-01-01

    Ultra high energy cosmic rays (UHECRs) are accelerated by the most energetic processes in the universe. Upon entering Earth’s atmosphere they produce particle showers known as extensive air showers (EASs). Observatories like the Pierre Auger Observatory sample the particles and light produced by the EASs through large particle detector arrays or nitrogen fluorescence detectors to ascertain the fundamental properties of UHECRs. The large sample of high quality data provided by the Pierre Auger Observatory can be attributed to the hybrid technique which utilizes the two aforementioned techniques simultaneously; however, the limitation of only being able to observe nitrogen fluorescence from EASs on clear moonless nights yields a limited 10% duty cycle for the hybrid technique. One proposal for providing high quality data at increased statistics is the observation of isotropic microwave emission from EASs, as such emission would be observed with a 100% duty cycle. Measurements of microwave emission from laboratory air plasmas conducted by Gorham et al. (2008) produced promising results indicating that the microwave emission should be observable using inexpensive detectors. The Microwave Detection of Air Showers (MIDAS) experiment was built at the University of Chicago to characterize the isotropic microwave emission from EASs and has collected 359 days of observational data at the location of the Pierre Auger experiment. We have performed a time coincidence analysis between this data and data from Pierre Auger and we report a null result. This result places stringent limits on microwave emission from EASs and demonstrates that the laboratory measurements of Gorham et al. (2008) are not applicable to EASs, thus diminishing the feasibility of using isotropic microwave emission to detect EASs.

  3. Search for cosmic gamma rays with the Carpet-2 extensive air shower array

    NASA Astrophysics Data System (ADS)

    Dzhappuev, D. D.; Petkov, V. B.; Kudzhaev, A. U.; Klimenko, N. F.; Lidvansky, A. S.; Troitsky, S. V.

    2016-06-01

    The present-day status of the problem of searching for primary cosmic gamma rays at energies above 100 TeV is discussed, as well as a proposal for a new experiment in this field. It is shown that an increase of the area of the muon detector of the Carpet-2 air shower array up to 410 square meters, to be realized in 2016, will make this array quite competitive with past and existing experiments, especially at modest energies. Some preliminary results of measurements made with smaller area of the muon detector are presented together with estimates of expected results to be obtained with a coming large-area muon detector.

  4. Performance of the Extensive Air Shower Array at the University of Puebla

    NASA Astrophysics Data System (ADS)

    Cotzomi, J.; Martinez, O.; Medina, M.; Moreno, E.; Salazar, H.; Pérez, L.; Ponce, G.; Villaseñor, L.; Garipov, G.; Khrenov, B.

    2003-07-01

    We report on the performance of the EAS-UAP extensive air shower array after one year of operation. The array is located at 19N 90W, 800 g /cm2 ; it was designed to measure the energy and arrival direction of primary cosmic rays with energies in the range of 1014 to 1016 eV. The array consists of 12 liquid scintillation detectors of 1m2 effective area distributed in a square grid of 20m that measure the lateral distribution function of the electromagnetic component and 3 large water Cherenkov detectors to help improve the measurement of the time profile of the signals.

  5. Novel method for detecting the hadronic component of extensive air showers

    SciTech Connect

    Gromushkin, D. M.; Volchenko, V. I.; Petrukhin, A. A.; Stenkin, Yu. V.; Stepanov, V. I.; Shchegolev, O. B.; Yashin, I. I.

    2015-05-15

    A novel method for studying the hadronic component of extensive air showers (EAS) is proposed. The method is based on recording thermal neutrons accompanying EAS with en-detectors that are sensitive to two EAS components: an electromagnetic (e) component and a hadron component in the form of neutrons (n). In contrast to hadron calorimeters used in some arrays, the proposed method makes it possible to record the hadronic component over the whole area of the array. The efficiency of a prototype array that consists of 32 en-detectors was tested for a long time, and some parameters of the neutron EAS component were determined.

  6. Photoproduction total cross section and shower development

    NASA Astrophysics Data System (ADS)

    Cornet, F.; García Canal, C. A.; Grau, A.; Pancheri, G.; Sciutto, S. J.

    2015-12-01

    The total photoproduction cross section at ultrahigh energies is obtained using a model based on QCD minijets and soft-gluon resummation and the ansatz that infrared gluons limit the rise of total cross sections. This cross section is introduced into the Monte Carlo system AIRES to simulate extended air showers initiated by cosmic ray photons. The impact of the new photoproduction cross section on common shower observables, especially those related to muon production, is compared with previous results.

  7. Measurement of the depth of maximum of extensive air showers above 10{18} eV.

    PubMed

    Abraham, J; Abreu, P; Aglietta, M; Ahn, E J; Allard, D; Allekotte, I; Allen, J; Alvarez-Muñiz, J; Ambrosio, M; Anchordoqui, L; Andringa, S; Anticić, T; Anzalone, A; Aramo, C; Arganda, E; Arisaka, K; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avila, G; Bäcker, T; Badagnani, D; Balzer, M; Barber, K B; Barbosa, A F; Barroso, S L C; Baughman, B; Bauleo, P; Beatty, J J; Becker, B R; Becker, K H; Bellétoile, A; Bellido, J A; Benzvi, S; Berat, C; Bergmann, T; Bertou, X; Biermann, P L; Billoir, P; Blanch-Bigas, O; Blanco, F; Blanco, M; Bleve, C; Blümer, H; Bohácová, 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; Busca, N G; Caballero-Mora, K S; Caramete, L; Caruso, R; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Chiavassa, A; Chinellato, J A; Chou, A; Chudoba, J; Clay, R W; Colombo, E; 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; Daumiller, K; Dawson, B R; de Almeida, R M; De Domenico, M; De Donato, C; de Jong, S J; De La Vega, G; de Mello Junior, W J M; de Mello Neto, J R T; De Mitri, I; de Souza, V; de Vries, K D; Decerprit, G; Del Peral, L; Deligny, O; Della Selva, A; Delle Fratte, C; Dembinski, H; Di Giulio, C; Diaz, J C; Díaz Castro, M L; Diep, P N; Dobrigkeit, C; D'Olivo, J C; Dong, P N; Dorofeev, A; Dos Anjos, J C; Dova, M T; D'Urso, D; Dutan, I; Duvernois, M A; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Etchegoyen, A; Facal San Luis, P; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferrero, A; Fick, B; Filevich, A; Filipcic, A; Fleck, I; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Fröhlich, U; Fulgione, W; Gamarra, R F; Gambetta, S; García, B; García Gámez, D; Garcia-Pinto, D; Garrido, X; Gelmini, G; Gemmeke, H; Ghia, P L; Giaccari, U; Giller, M; Glass, H; Goggin, L M; Gold, M S; Golup, G; Gomez Albarracin, F; Gómez Berisso, M; Gonçalves, P; Gonzalez, D; Gonzalez, J G; Góra, D; Gorgi, A; Gouffon, P; Gozzini, S R; Grashorn, E; Grebe, S; Grigat, M; Grillo, A F; Guardincerri, Y; Guarino, F; Guedes, G P; Hague, J D; Halenka, V; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hojvat, C; Holmes, V C; Homola, P; Hörandel, J R; Horneffer, A; Hrabovský, M; Huege, T; Hussain, M; Iarlori, M; Insolia, A; Ionita, F; Italiano, A; Jiraskova, S; Kadija, K; Kaducak, M; Kampert, K H; Karova, T; Kasper, P; Kégl, B; Keilhauer, B; Keivani, A; Kelley, J; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapik, R; Knapp, J; Koang, D-H; Krieger, A; Krömer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, K; Kunka, N; Kusenko, A; La Rosa, G; Lachaud, C; Lago, B L; Lautridou, P; Leão, M S A B; Lebrun, D; Lebrun, P; Lee, J; Leigui de Oliveira, M A; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; López, R; Lopez Agüera, A; Louedec, K; Lozano Bahilo, J; Lucero, A; Ludwig, M; Lyberis, H; Maccarone, M C; Macolino, C; Maldera, S; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, V; Maris, I C; Marquez Falcon, H R; Marsella, G; Martello, D; Martínez Bravo, O; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; McEwen, M; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Meurer, C; Micanović, S; Micheletti, M I; Miller, W; Miramonti, L; Mollerach, S; Monasor, M; Monnier Ragaigne, D; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Morris, C; Mostafá, M; Mueller, S; Muller, M A; Mussa, R; Navarra, G; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nhung, P T; Nierstenhoefer, N; Nitz, D; Nosek, D; Nozka, L; Nyklicek, M; Oehlschläger, J; Olinto, A; Oliva, P; Olmos-Gilbaja, V M; Ortiz, M; Pacheco, N; Pakk Selmi-Dei, D; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parlati, S; Parra, A; Parrisius, J; Parsons, R D; Pastor, S; Paul, T; Pavlidou, V; Payet, K; Pech, M; Pekala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrinca, P; Petrolini, A; Petrov, Y; Petrovic, J; Pfendner, C; Piegaia, R; Pierog, T; Pimenta, M; Pirronello, V; Platino, M; Ponce, V H; Pontz, M; Privitera, P; Prouza, M; Quel, E J; Rautenberg, J; Ravel, O; Ravignani, D; Redondo, A; Revenu, B; Rezende, F A S; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rivière, C; Rizi, V; Robledo, C; Rodriguez, G; Rodriguez Martino, J; Rodriguez Rojo, J; Rodriguez-Cabo, I; Rodríguez-Frías, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Salamida, F; Salazar, H; Salina, G; Sánchez, F; Santander, M; Santo, C E; Santos, E; Santos, E M; Sarazin, F; Sarkar, S; Sato, R; Scharf, N; Scherini, V; Schieler, H; Schiffer, P; Schmidt, A

    2010-03-05

    We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

  8. Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV

    SciTech Connect

    Abraham, J.; Abreu, P.; Aglietta, M.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; /Lisbon, IST /Boskovic Inst., Zagreb

    2010-02-01

    We describe the measurement of the depth of maximum, X{sub max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10{sup 18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{sub -21}{sup +35}) g/cm{sup 2}/decade below 10{sup 18.24 {+-} 0.05}eV, and (24 {+-} 3) g/cm{sup 2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{sup 2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

  9. The primary composition beyond 10 to the 5th power GeV as deduced from high energy hadrons and muons in air showers

    NASA Technical Reports Server (NTRS)

    Grieder, P. K. F.

    1985-01-01

    Data obtained from a large set of air shower simulation calculations with use of highly refined hadronic interaction and shower simulation model are presented, in an attempt to solve the problem of primary chemical composition beyond 100,000 GeV total energy. It is rated that high energy hadrons in air showers offer a rather unique primary mass signature and show that the interpretation of high energy muon data is much more ambiguous. Predictions are compared with experimental data.

  10. Repeated cold showers as a method of habituating humans to the initial responses to cold water immersion.

    PubMed

    Eglin, Clare M; Tipton, Michael J

    2005-03-01

    The hypothesis that the initial responses to cold water immersion could be attenuated by repeated cold showers was tested. Eighteen (13 men, 5 women) non-habituated subjects undertook two 3-min head-out seated immersions into stirred water at 10 degrees C wearing swim wear. The immersions were separated by 4 days during which time they took six cold showers. The subjects were randomly split into three groups with different showering regimes: 3 min at 10 degrees C on the back (10B); 3 min at 15 degrees C on the back (15B); and 30 s at 10 degrees C on the back followed by 30 s on the front (10BF). Over the first 30 s of immersion respiratory frequency ( f (R)) was reduced by 21% in groups 10B and 10BF from 54 (14) to 44 (16) breaths.min(-1) ( P <0.05), and 33 (8) to 26 (10) breaths.min(-1) ( P <0.05) respectively, following repeated showers. Group 15B showed no change in f (R). The tachycardia induced on immersion in water at 10 degrees C was not reduced by repeated showers except in group 15B during the last 150 s [from 119 (23) to 105 (25) beats.min(-1), P <0.05]. Repeated showering in water at 10 degrees C reduced the respiratory drive (as measured by f (R)) during head-out immersion in water at the same temperature. No such habituation was observed with repeated showers in warmer water (15 degrees C). It is concluded that when the body surface area cooled is the same, the rate of change of skin temperature is an important factor in determining the degree of habituation produced.

  11. Interpretation of measurements of the number of muons in extensive air shower experiments

    NASA Astrophysics Data System (ADS)

    Prado, Raul R.; Conceição, Ruben; Pimenta, Mário; de Souza, Vitor

    2016-10-01

    In this paper we analyze the energy evolution of the muon content of air showers between 1018.4 and 1019.6 eV to be able to determine the most likely mass composition scenario from future number of muons measurements. The energy and primary mass evolution of the number of muons is studied based on the Heitler-Matthews model and Monte Carlo simulation of the air shower. A simple model to describe the evolution of the first and second moments of number of muons distributions is proposed and validated. An analysis approach based on the comparison between this model's predictions and data to discriminate among a set of composition scenarios is presented and tested with simulations. It is shown that the composition scenarios can be potentially discriminated under the conditions imposed by the method. The discrimination power of the proposed analysis is stable under systematic changes of the absolute number of muons from model predictions and on the scale of the reconstructed energy.

  12. Hybrid Extensive Air Shower Detector Array at the University of Puebla to Study Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Martínez, O.; Pérez, E.; Salazar, H.; Villaseñor, L.

    We describe the design of an extensive air shower detector array built in the Campus of the University of Puebla (located at 19°N, 90°W, 800 gcm -2) to measure the energy and arrival direction of primary cosmic rays with energies around 1015 eV. The array consists of 18 liquid scintillator detectors (12 in the first stage) and 6 water Cherenkov detectors (one of 10 m 2 cross section and five smaller ones of 1.86 m 2 cross section), distributed in a square grid with a detector spacing of 20 m over an area of 4000 m 2. In this paper we discuss the calibration and stability of the array, and discuss the capability of hybrid arrays, such as this one consisting of water Cherenkov and liquid scintillator detectors, to allow a separation of the electromagnetic and muon components of extensive air showers. This separation plays an important role in the determination of the mass and identity of the primary cosmic ray. This facility is also used to train students interested in the field of cosmic rays.

  13. First upper limits on the radar cross section of cosmic-ray induced extensive air showers

    NASA Astrophysics Data System (ADS)

    Abbasi, R. U.; Abe, M.; Abou Bakr Othman, M.; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Besson, D.; Blake, S. A.; Byrne, M.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Farhang-Boroujeny, B.; Fujii, T.; Fukushima, M.; Gillman, W. H.; Goto, T.; Hanlon, W.; Hanson, J. C.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jayanthmurthy, C.; 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.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kunwar, S.; 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, K.; 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.; Prohira, S.; Pshirkov, M. S.; Rezazadeh-Reyhani, A.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Schurig, D.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takai, H.; 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.; Venkatesh, S.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

    2017-01-01

    TARA (Telescope Array Radar) is a cosmic ray radar detection experiment colocated with Telescope Array, the conventional surface scintillation detector (SD) and fluorescence telescope detector (FD) near Delta, Utah, U.S.A. The TARA detector combines a 40 kW, 54.1 MHz VHF transmitter and high-gain transmitting antenna which broadcasts the radar carrier over the SD array and within the FD field of view, towards a 250 MS/s DAQ receiver. TARA has been collecting data since 2013 with the primary goal of observing the radar signatures of extensive air showers (EAS). Simulations indicate that echoes are expected to be short in duration (∼ 10 μs) and exhibit rapidly changing frequency, with rates on the order 1 MHz/μs. The EAS radar cross-section (RCS) is currently unknown although it is the subject of over 70 years of speculation. A novel signal search technique is described in which the expected radar echo of a particular air shower is used as a matched filter template and compared to waveforms obtained by triggering the radar DAQ using the Telescope Array fluorescence detector. No evidence for the scattering of radio frequency radiation by EAS is obtained to date. We report the first quantitative RCS upper limits using EAS that triggered the Telescope Array Fluorescence Detector.

  14. Study of muon bundles from extensive air showers with the ALICE detector at CERN LHC

    NASA Astrophysics Data System (ADS)

    Shtejer, K.

    2016-05-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic-ray interactions in the upper atmosphere. The large size and excellent tracking capability of the ALICE Time Projection Chamber are exploited to study the muonic component of extensive air showers. We present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. The latest version of the QGSJET hadronic interaction model was used to simulate the development of the resulting air showers. High multiplicity events containing more than 100 reconstructed muons were also studied. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP without satisfactory explanations for the frequency of the highest multiplicity events. We demonstrate that the high muon-multiplicity events observed in ALICE stem from primary cosmic rays with energies above 1016 eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range.

  15. Horizontal Tau air showers from mountains in deep vally :Traces of Ultrahigh neutrino tau

    NASA Astrophysics Data System (ADS)

    Fargion, Daniele

    1999-08-01

    Ultra High Energy (UHE) Tau neutrino may lead to a very peculiar imprint in future underground K m3 detectors in water and ice as well as in air: rarest secondary tau tracks and decay which may exceed the muon ones. Indeed Bremsstrahlung at high energy lead to longer tracks for heavier leptons. Radiation lenght grows nearly with the square of the lepton mass. Indeed electrons are too light and their trace in matter is negligible (decimeters) muon are much better observed, while tau are too short life time and short range to be found. However, because relativistic time expansion, UHE tau traces in matter, above 1017 eV , are relativistically boosted overcoming the corresponding muon tracks, already bounded by bremsstrahlung logaritmic regime. The tau crossing for Kms in water or ice may be confused with common muon tracks; their tau decay may be missunderstood as muonic catastrophic brehmstrallung interactions. To economize UHE tau dicovery, we suggest to look the tau decay in air into the deep valleys montains, like Canyons or deep in escavation mines where horizontal air showers induce fluoresce or Cerenkov lights. The mountain valley width screens from horizontal secondary muons. The valley height increases the solid angle view. The horizontal air Kms-size gap offer a strong discriminator to filter UHE muons against tau. Tens event a year at PeV ( W resonance peak) energies in K m3 excavation gap should be observable . Hunting air shower in the night toward high mountains in Canyons or in a deep excavation may be the best and cheapest way to discover UHE neutrinos , either born by electron antineutrino scattering on electrons at PeV energies, or by direct tau neutrino possibly relic of muonic flavour oscillation even at EeV energies.

  16. Progress report on a new search for free e/3 quarks in the cores of 10(15) - 10(16) eV air showers

    NASA Technical Reports Server (NTRS)

    Hodson, A. L.; Bull, R. M.; Taylor, R. S.; Belford, C. H.

    1985-01-01

    The Leeds 3 sq m Wilson cloud chamber is being used in a new search for free e/3 quarks close to the axes of 10 to the 15th power - 10 to the 16th power eV air showers. A ratio trigger circuit is used to detect the incidence of air shower cores; the position of the shower center and the axis direction are determined from photographs of current-limited spark chambers. It is thus possible, for the first time, to know where we have looked for quarks in air showers and to select for scanning only those cloud chamber photographs where we have good evidence that the shower axis was close to the chamber. 250 g/sq cm of lead/concrete absorber above the cloud chamber serve to reduce particle densities and make a quark search possible very close to the shower axes. The current status of the search is given.

  17. A method of observing cherenkov light from extensive air shower at Yakutsk EAS array

    NASA Astrophysics Data System (ADS)

    Timofeev, Lev; Anatoly, Ivanov

    2016-07-01

    Proposed a new method for measuring the cherenkov light from the extensive air shower (EAS) of cosmic rays (CR), which allows to determine not only the primary particle energy and angle of arrival, but also the parameters of the shower in the atmosphere - the maximum depth and "age". For measurements Cherenkov light produced by EAS is proposed to use a ground network of wide-angle telescopes which are separated from each other by a distance 100-300 m depending on the total number of telescopes operating in the coincidence signals, acting autonomously, or includes a detector of the charged components, radio waves, etc. as part of EAS. In a results such array could developed, energy measurement and CR angle of arrival data on the depth of the maximum and the associated mass of the primary particle generating by EAS. This is particularly important in the study of galactic cosmic ray in E> 10^14 eV, where currently there are no direct measurements of the maximum depth of the EAS.

  18. Temporal signatures of the Cherenkov light induced by extensive air showers of cosmic rays detected with the Yakutsk array

    NASA Astrophysics Data System (ADS)

    Ivanov, A. A.; Timofeev, L. V.

    2016-05-01

    We analyze temporal characteristics of signals from the wide field-of-view (WFOV) Cherenkov telescope (CT) detecting extensive air showers (EAS) of cosmic rays (CRs) in coincidence with surface detectors of the Yakutsk array. Our aim is to reveal causal relationships between measured characteristics and physical properties of EAS.

  19. Future Extensive Air Shower arrays: From Gamma-Ray Astronomy to Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Di Sciascio, Giuseppe

    2016-07-01

    Despite large progresses in building new detectors and in the analysis techniques, the key questions concerning the origin, acceleration and propagation of Galactic Cosmic Rays are still open. A number of new EAS arrays is in progress. The most ambitious and sensitive project between them is LHAASO, a new generation multi-component experiment to be installed at very high altitude in China (Daocheng, Sichuan province, 4400 m a.s.l.). The experiment will face the open problems through a combined study of photon- and charged particle-induced extensive air showers in the wide energy range 1011 - 1018 eV. In this paper the status of the experiment will be summarized, the science program presented and the outlook discussed in comparison with leading new projects.

  20. Electronics for the Extensive Air Shower Detector Array at the University of Puebla

    NASA Astrophysics Data System (ADS)

    Pérez, E.; Conde, R.; Martínez, O.; Murrieta, T.; Salazar, H.; Villaseñor, L.

    2006-09-01

    In this paper we describe in detail the electronics cards that were designed to be the basis of the data acquisition system (DAS) of the extensive air shower detector array built in the Campus of the University of Puebla. The purpose of this observatory is to measure the energy and arrival direction of primary cosmic rays with energies around 1015 eV. The array consists of 18 liquid scintillator detectors (12 in the first stage) and 6 water Cherenkov detectors (one of 10 m2 cross section and five smaller ones of 1.86 m2 cross section), distributed in a square grid with a detector spacing of 20 m over an area of 4000 m2. The electronics described here uses analog to digital converters of 10 bits working at a sampling speed of 40 MS/s and field-programmable gate array (FPGA).

  1. Testing of Large Diameter Fresnel Optics for Space Based Observations of Extensive Air Showers

    NASA Technical Reports Server (NTRS)

    Adams, James H.; Christl, Mark J.; Young, Roy M.

    2011-01-01

    The JEM-EUSO mission will detect extensive air showers produced by extreme energy cosmic rays. It operates from the ISS looking down on Earth's night time atmosphere to detect the nitrogen fluorescence and Cherenkov produce by the charged particles in the EAS. The JEM-EUSO science objectives require a large field of view, sensitivity to energies below 50 EeV, and must fit within available ISS resources. The JEM-EUSO optic module uses three large diameter, thin plastic lenses with Fresnel surfaces to meet the instrument requirements. A bread-board model of the optic has been manufactured and has undergone preliminary tests. We report the results of optical performance tests and evaluate the present capability to manufacture these optical elements.

  2. Cosmogenic neutrinos and signals of TeV gravity in air showers and neutrino telescopes.

    PubMed

    Illana, J I; Masip, M; Meloni, D

    2004-10-08

    The existence of extra dimensions allows the possibility that the fundamental scale of gravity is at the TeV. If that is the case, gravity could dominate the interactions of ultrahigh energy cosmic rays. In particular, the production of microscopic black holes by cosmogenic neutrinos has been estimated in a number of papers. We consider here gravity-mediated interactions at larger distances, where they can be calculated in the eikonal approximation. We show that for the expected flux of cosmogenic neutrinos these elastic processes give a stronger signal than black hole production in neutrino telescopes. Taking the bounds on the higher-dimensional Planck mass M(D) (D=4 + n) from current air shower experiments, for n=2(6) elastic collisions could produce up to 118 (34) events per year at IceCube. On the other hand, the absence of any signal would imply a bound of M(D) > or approximately 5 TeV.

  3. On the extension of the sensitive area of an extensive air shower surface array

    NASA Astrophysics Data System (ADS)

    Hedayati, Kh. H.

    2017-02-01

    A large distance between true and reconstructed core locations of an extensive air shower (EAS) may result in great systematic mis-estimation of EAS parameters. The reconstruction of those EASs whose core locations are outside the boundary of a surface array (outside EAS (OEAS)) results in a large distance of the reconstructed core location from the true one, especially when the true core is far outside the array. Although it may not be mentioned, the rejection of OEASs is a necessary and important step in the reconstruction procedure of an EAS. In this paper, an existing technique is optimized for the rejection of OEASs. The simultaneous use of this technique and a recently developed approach for reconstructing the core location of an EAS can significantly increase the sensitive area of a surface array.

  4. Air shower simulation for WASAVIES: warning system for aviation exposure to solar energetic particles.

    PubMed

    Sato, T; Kataoka, R; Yasuda, H; Yashiro, S; Kuwabara, T; Shiota, D; Kubo, Y

    2014-10-01

    WASAVIES, a warning system for aviation exposure to solar energetic particles (SEPs), is under development by collaboration between several institutes in Japan and the USA. It is designed to deterministically forecast the SEP fluxes incident on the atmosphere within 6 h after flare onset using the latest space weather research. To immediately estimate the aircrew doses from the obtained SEP fluxes, the response functions of the particle fluxes generated by the incidence of monoenergetic protons into the atmosphere were developed by performing air shower simulations using the Particle and Heavy Ion Transport code system. The accuracy of the simulation was well verified by calculating the increase count rates of a neutron monitor during a ground-level enhancement, combining the response function with the SEP fluxes measured by the PAMELA spectrometer. The response function will be implemented in WASAVIES and used to protect aircrews from additional SEP exposure.

  5. Underground Prototype Water Cherenkov Muon Detector with the Tibet Air Shower Array

    SciTech Connect

    Amenomori, M.; Nanjo, H.; Bi, X. J.; Ding, L. K.; Feng, Zhaoyang; He, H. H.; Hu, H. B.; Lu, H.; Lu, S. L.; Ren, J. R.; Tan, Y. H.; Wang, B.; Wang, H.; Wang, Y.; Wu, H. R.; Zhang, H. M.; Zhang, J. L.; Zhang, Y.; Chen, D.; Kawata, K.

    2008-12-24

    We are planning to build a 10,000 m{sup 2} water-Cherenkov-type muon detector (MD) array under the Tibet air shower (AS) array. The Tibet AS+MD array will have the sensitivity to detect gamma rays in the 100 TeV region by an order of the magnitude better than any other previous existing detectors in the world. In the late fall of 2007, a prototype water Cherenkov muon detector of approximately 100 m{sup 2} was constructed under the existing Tibet AS array. The preliminary data analysis is in good agreement with our MC simulation. We are now ready for further expanding the underground water Cherenkov muon detector.

  6. On the extension of the sensitive area of an extensive air shower surface array

    NASA Astrophysics Data System (ADS)

    Kh., H. Hedayati

    2017-04-01

    A large distance between true and reconstructed core locations of an extensive air shower (EAS) may result in great systematic mis-estimation of EAS parameters. The reconstruction of those EASs whose core locations are outside the boundary of a surface array (outside EAS (OEAS)) results in a large distance of the reconstructed core location from the true one, especially when the true core is far outside the array. Although it may not be mentioned, the rejection of OEASs is a necessary and important step in the reconstruction procedure of an EAS. In this paper, an existing technique is optimized for the rejection of OEASs. The simultaneous use of this technique and a recently developed approach for reconstructing the core location of an EAS can significantly increase the sensitive area of a surface array.

  7. Discovering Ultra-High-Energy Neutrinos through Horizontal and Upward τ Air Showers: Evidence in Terrestrial Gamma Flashes?

    NASA Astrophysics Data System (ADS)

    Fargion, D.

    2002-05-01

    Ultra-high-energy (UHE) neutrinos ντ, ντ, and νe at PeV and higher energies may induce τ air showers whose detectability is amplified millions to billions of times by their secondaries. We considered UHE ντ-N and UHE νe-e interactions underneath mountains as a source of such horizontal amplified τ air showers. We also consider vertical upward UHE ντ-N interactions (UPTAUs) on Earth's crust, leading to UHE τ air showers or interactions at the horizon edges (HORTAUs), and their beaming toward high mountain gamma, X-ray, and Cerenkov detectors, and we show their detectability. We notice that such rare upward τ air showers, UPTAUs and HORTAUs, may even hit nearby balloons or satellites and flash them with short diluted gamma bursts at the edge of the Compton Gamma Ray Observatory detection threshold. We suggest the possibility of identifying these events with recently discovered (BATSE) terrestrial gamma flashes (TGFs), and we argue for their probable UHE τ-UHE ντ origin. From these data, approximated UHE ντ fluxes and Δmνμντ lower bounds are derived. Known X-ray, gamma, and TeV active Galactic and extragalactic sources have been identified in most TGF arrival directions. Maximal EGRET activity in the Galactic center overlaps with the maximal TGF flux. The UHE cosmic-ray (UHECR) Akino Giant Air Shower Array anisotropy at 1018 eV also shows possible correlations with TGF events. The unique UHECR triplet in AGASA clustering, pointing toward BL Lac 1ES 0806+524, finds within its error box a corresponding TGF event, BATSE trigger 2444. Finally, a partial TGF Galactic signature, combined with the above correlations, suggests an astrophysical τ origin of TGF events.

  8. Test of a Hadronic Interaction Model by a Multidimensional Analysis of Lateral and Longitudinal Air-Shower Observables at KASCADE

    NASA Astrophysics Data System (ADS)

    Badea, F.; Antoni, T.; Apel, W. D.; Bekk, K.; Bercuci, A.; Blümer, H.; Bozdog, H.; Brancus, I. M.; Büttner, C.; Chilingarian, A.; Daumiller, K.; Doll, P.; Engel, R.; Engler, J.; Feßler, F.; Gils, H. J.; Glasstetter, R.; Haungs, A.; Heck, D.; Hörandel, J. R.; Iwan, A.; Kampert, K-H.; Klages, H. O.; Maier, G.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Müller, M.; Obenland, R.; Oehschläger, J.; Ostapchenko, S.; Petcu, M.; Rebel, H.; Risse, M.; Roth, M.; Schatz, G.; Schieler, H.; Scholz, J.; Thouw, T.; Ulrich, H.; van Buren, J.; Vardanyan, A.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2003-07-01

    The multi-detector experiment KASCADE enables simultaneous observations of parameters describing the lateral and longitudinal development of Extensive Air Showers. The present analysis is fo cused on Field Array and Muon Tracking detectors of KASCADE. The Field Array (FA) provides the numbers of electrons and muons in the shower and the Muon Tracking Detector (MTD) measures angles-of-incidence of muons which are related to the longitudinal development of EAS. An identical two step deconvolution method (on primary mass using a Bayesian approach and on primary energy) is performed to calculate the primary mass and energy of cosmic rays using the correlation of FA observables only and by adding MTD observables. The consistency of the CORSIKA/QGSJET simulation code in describing the correlation between lateral and longitudinal developments of the shower is studied by comparing the results obtained from the two sets of observables.

  9. The effect of the atmospheric condition on the extensive air shower analysis at the Telescope Array experiment

    SciTech Connect

    Kobayashi, Y.; Tsunesada, Y.; Tokuno, H.; Kakimoto, F.; Tomida, T.

    2011-09-22

    The accuracies in determination of air shower parameters such as longitudinal profiles or primary energies with the fluorescence detection technique are strongly dependent on atmospheric conditions of the molecular and aerosol components. Moreover, air fluorescence photon yield depends on the atmospheric density, and the transparency of the air for fluorescence photons depends on the atmospheric conditions from EAS to FDs. In this paper, we describe the atmospheric monitoring system in the Telescope Array (TA experiment), and the impact of the atmospheric conditions in air shower reconstructions. The systematic uncertainties of the determination of the primary cosmic ray energies and of the measurement of depth of maximum development (X{sub max}) of EASs due to atmospheric variance are evaluated by Monte Carlo simulation.

  10. Radio wave emitted by an extensive air showers in 10KHz to 1MHz region

    NASA Technical Reports Server (NTRS)

    Nichimura, J.

    1985-01-01

    The importance of radio waves in a frequency range of less than 1MHz in an EAS shower is discussed. Estimates of radio intensities at 10KHz, 100KHz and 1MHz in EAS showers made on the basis of the Kahn-Lerche theory. Negative charge excess in a shower is the main source of low frequency radio emission, in spite of the importance of the contribution of transverse current in the geomagnetic field in a higher frequency range. An estimate is also made for radio intensity produced when the shower hits the ground. The contribution of this process seems to be important at a large distance, i.e., beyond 1km from the shower axis.

  11. Muons in gamma showers

    NASA Technical Reports Server (NTRS)

    Stanev, T.; Vankov, C. P.; Halzen, F.

    1985-01-01

    Muon production in gamma-induced air showers, accounting for all major processes. For muon energies in the GeV region the photoproduction is by far the most important process, while the contribution of micron + micron pair creation is not negligible for TeV muons. The total rate of muons in gamma showers is, however, very low.

  12. The muon component in extensive air showers and new p+C data in fixed target experiments

    SciTech Connect

    Meurer, C.; Bluemer, J.; Engel, R.; Haungs, A.; Roth, M.

    2007-03-19

    One of the most promising approaches to determine the energy spectrum and composition of the cosmic rays with energies above 1015 eV is the measurement of the number of electrons and muons produced in extensive air showers (EAS). Therefore simulation of air showers using electromagnetic and hadronic interaction models are necessary. These simulations show uncertainties which come mainly from hadronic interaction models. One aim of this work is to specify the low energy hadronic interactions which are important for the muon production in EAS. Therefore we simulate extensive air showers with a modified version of the simulation package CORSIKA. In particular we investigate in detail the energy and the phase space regions of secondary particle production, which are most important for muon production. This phase space region is covered by fixed target experiments at CERN. In the second part of this work we present preliminary momentum spectra of secondary {pi}+ and {pi}- in p+C collisions at 12 GeV/c measured with the HARP spectrometer at the PS accelerator at CERN. In addition we use the new p+C NA49 data at 158 GeV/c to check the reliability of hadronic interaction models for muon production in EAS. Finally, possibilities to measure relevant quantities of hadron production in existing and planned accelerator experiments are discussed.

  13. Observation of Multi-TeV Gamma Rays from the Crab Nebula using the Tibet Air Shower Array.

    PubMed

    Amenomori; Ayabe; Cao; Danzengluobu; Ding; Feng; Fu; Guo; He; Hibino; Hotta; Huang; Huo; Izu; Jia; Kajino; Kasahara; Katayose; Labaciren; Li; Lu; Lu; Luo; Meng; Mizutani; Mu; Nanjo; Nishizawa; Ohnishi; Ohta; Ouchi; Ren; Saito; Sakata; Sasaki; Shi; Shibata; Shiomi; Shirai; Sugimoto; Taira; Tan; Tateyama; Torii; Utsugi; Wang; Wang; Xu; Yamamoto; Yu; Yuan; Yuda; Zhang; Zhang; Zhang; Zhang; Zhang; Zhaxisangzhu; Zhaxiciren; Zhou; Collaboration)

    1999-11-10

    The Tibet experiment, operating at Yangbajing (4300 m above sea level), is the lowest energy air shower array, and the new high-density array constructed in 1996 is sensitive to gamma-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV gamma-rays and a signal was detected at the 5.5 sigma level. We also obtained the energy spectrum of gamma-rays in the energy region above 3 TeV which partially overlaps those observed with imaging atmospheric Cerenkov telescopes. The Crab spectrum observed in this energy region can be represented by the power-law fit dJ&parl0;E&parr0;&solm0;dE=&parl0;4.61+/-0.90&parr0;x10-12&parl0;E&solm0;3 TeV&parr0;-2.62+/-0.17 cm-2 s-1 TeV-1. This is the first observation of gamma-ray signals from point sources with a conventional air shower array using scintillation detectors.

  14. The Telescope Array RADAR (TARA) Project and the Search for the Radar Signature of Cosmic Ray Induced Extensive Air Showers

    NASA Astrophysics Data System (ADS)

    Prohira, Steven; TARA Collaboration; Telescope Array Collaboration

    2016-03-01

    The TARA (Telescope Array Radar) cosmic ray detector has been in operation since May 2013. It is the most ambitious effort to date to test an idea that originated in the 1940's: that ionization produced by cosmic ray extensive air showers should reflect electromagnetic radiation. The observation of this effect would open the possibility that remote-sensing radar technology could be used to detect and reconstruct extensive air showers, thus increasing the aperture available for the study of the highest-energy cosmic rays. TARA employs a bi-static radar configuration, consisting of a 25 kW, 5 MW ERP transmitter at 54.1 MHz broadcasting across the Telescope Array surface detector. 40 km distant, a set of log-periodic receiver antennas are read out by two independent data acquisition systems employing different techniques to select signals of the form expected for radar targets moving at close to the speed of light. In this talk, we describe the TARA detector and present the first quantitative limits on the radar cross-section of extensive air showers.

  15. The Cosmic Ray Observatory Project in Nebraska -- a education and research project to study extensive air showers

    NASA Astrophysics Data System (ADS)

    Snow, G. R.

    2005-12-01

    The Cosmic Ray Observatory Project (CROP) is a statewide education and research experiment involving Nebraska high school students, teachers, and college undergraduates in the study of extensive cosmic-ray air showers. A network of high school teams construct, install, and operate school-based detectors in coordination with University of Nebraska physics professors and graduate students. The detector system at each school is an array of scintillation counters recycled from the Chicago Air Shower Array in weather-proof enclosures on the school roof, with a GPS receiver providing a time stamp for cosmic-ray events. The detectors are connected to triggering electronics and a data-acquisition PC inside the building. Students share data via the Internet to search for time coincidences with other sites. CROP has enlisted 26 schools in its first 5 years of operation with the aim of expanding to the 314 high schools in the state over the next several years. Recent successes and prelinimary data on air shower searches will be presented. The outlook for statewise expansion will be discussed.

  16. Reconstruction of air shower muon densities using segmented counters with time resolution

    NASA Astrophysics Data System (ADS)

    Ravignani, D.; Supanitsky, A. D.; Melo, D.

    2016-09-01

    Despite the significant experimental effort made in the last decades, the origin of the ultra-high energy cosmic rays is still largely unknown. Key astrophysical information to identify where these energetic particles come from is provided by their chemical composition. It is well known that a very sensitive tracer of the primary particle type is the muon content of the showers generated by the interaction of the cosmic rays with air molecules. We introduce a likelihood function to reconstruct particle densities using segmented detectors with time resolution. As an example of this general method, we fit the muon distribution at ground level using an array of counters like AMIGA, one of the Pierre Auger Observatory detectors. For this particular case we compare the reconstruction performance against a previous method. With the new technique, more events can be reconstructed than before. In addition the statistical uncertainty of the measured number of muons is reduced, allowing for a better discrimination of the cosmic ray primary mass.

  17. Extensive Air Shower Array at the University of Puebla (EAS-BUAP)

    NASA Astrophysics Data System (ADS)

    Salazar, H.; Martinez, O.; Moreno, E.; Cotzomi, J.; Villaseñor, L.

    2003-06-01

    We describe the design and operation of the first stage of the EAS-UAP extensive air shower array, as a detector of very high energy cosmic rays (1016 > Eo > 1014eV). The array is located at the Campus of Puebla University. It consist of 18 liquid scintillator detectors, with an active surface of 1 m2 each and a detector spacing of 20 m in a square grid. One Auger Water Cherenkov detector is also included as part of the array. In this report we discuss the stability, the calibration, the arrival direction and lateral distribution function reconstruction capabilities of the detector array, as derived from the 10 detectors in operation in the first stage. Our results shows that the angular accuracy in arrival direction is less than 5.5° in the range from 20° to 60°. The measurements in the Water Cherenkov Detector show us the possibility to separete electromagnetic and muon component. The main characteristics of the array allow us also to use it as educational and training facility.

  18. ELF/VLF radio from runaway breakdown and cosmic ray air showers

    NASA Astrophysics Data System (ADS)

    Fullekrug, M.; Roussel-Dupre, R.; Rodger, C. J.; Falcke, H.; Huege, T.

    2005-12-01

    The natural electromagnetic environment at low radio frequencies from 10 Hz to 30 kHz (ELF/VLF) is dominated by impulsive bursts from lightning discharges in the troposphere. Particularly intense positive lightning discharges can cause transient luminous events (TLEs) in the mesosphere, denoted sprites, which mainly result from the quasi-static heating of the neutral gas in the mesosphere. The most spectacular 20 % of sprites produce radio signals at extremely-low frequencies from 10 Hz to 3 kHz (ELF), which are currently believed to result mainly from conventional mesospheric breakdown. Alternatively, the observed radio signals may be dominated by relativistic runaway breakdown in the mesosphere. The respective current source functions of conventional and relativistic breakdown are connected to an ELF/VLF propagation model to calculate the electromagnetic fields of both physical processes at a distance and to determine the most appropriate method to discriminate between the two different physical processes. Extensive cosmic ray air showers from ultra-high energy extra-galactic cosmic rays >100 EeV similarly produce radio signals up to the high frequency range from 3-300 MHz (HF/VHF). The ELF/VLF radio signals from this cosmic ray current source function is calculated by using the same ELF/VLF propagation model. The prospects for the detection of the radio signals from relativistic runaway breakdown and cosmic rays are discussed in the light of reported instrumental sensitivities.

  19. OBSERVATION OF COSMIC-RAY ANISOTROPY WITH THE ICETOP AIR SHOWER ARRAY

    SciTech Connect

    Aartsen, M. G.; Abbasi, R.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Baker, M.; Abdou, Y.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Altmann, D.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beattie, K.; Beatty, J. J.; Bechet, S.; Tjus, J. Becker; Becker, K.-H.; Collaboration: IceCube Collaboration; and others

    2013-03-01

    We report on the observation of anisotropy in the arrival direction distribution of cosmic rays at PeV energies. The analysis is based on data taken between 2009 and 2012 with the IceTop air shower array at the south pole. IceTop, an integral part of the IceCube detector, is sensitive to cosmic rays between 100 TeV and 1 EeV. With the current size of the IceTop data set, searches for anisotropy at the 10{sup -3} level can, for the first time, be extended to PeV energies. We divide the data set into two parts with median energies of 400 TeV and 2 PeV, respectively. In the low energy band, we observe a strong deficit with an angular size of about 30 Degree-Sign and an amplitude of (- 1.58 {+-} 0.46{sub stat} {+-} 0.52{sub sys}) Multiplication-Sign 10{sup -3} at a location consistent with previous observations of cosmic rays with the IceCube neutrino detector. The study of the high energy band shows that the anisotropy persists to PeV energies and increases in amplitude to (- 3.11 {+-} 0.38{sub stat} {+-} 0.96{sub sys}) Multiplication-Sign 10{sup -3}.

  20. Detection and imaging of atmospheric radio flashes from cosmic ray air showers.

    PubMed

    Falcke, H; Apel, W D; Badea, A F; Bähren, L; Bekk, K; Bercuci, A; Bertaina, M; Biermann, P L; Blümer, J; Bozdog, H; Brancus, I M; Buitink, S; Brüggemann, M; Buchholz, P; Butcher, H; Chiavassa, A; Daumiller, K; de Bruyn, A G; de Vos, C M; Di Pierro, F; Doll, P; Engel, R; Gemmeke, H; Ghia, P L; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Horneffer, A; Huege, T; Kampert, K-H; Kant, G W; Klein, U; Kolotaev, Y; Koopman, Y; Krömer, O; Kuijpers, J; Lafebre, S; Maier, G; Mathes, H J; Mayer, H J; Milke, J; Mitrica, B; Morello, C; Navarra, G; Nehls, S; Nigl, A; Obenland, R; Oehlschläger, J; Ostapchenko, S; Over, S; Pepping, H J; Petcu, M; Petrovic, J; Plewnia, S; Rebel, H; Risse, A; Roth, M; Schieler, H; Schoonderbeek, G; Sima, O; Stümpert, M; Toma, G; Trinchero, G C; Ulrich, H; Valchierotti, S; van Buren, J; van Cappellen, W; Walkowiak, W; Weindl, A; Wijnholds, S; Wochele, J; Zabierowski, J; Zensus, J A; Zimmermann, D

    2005-05-19

    The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

  1. The muon content of gamma-ray showers

    NASA Technical Reports Server (NTRS)

    Edwards, P. G.; Protheroe, R. J.

    1985-01-01

    The result of a calculation of the expected number of muons in gamma ray initiated and cosmic ray initiated air showers using a realistic model of hadronic collisions in an effort to understand the available experimental results and to assess the feasibility of using the muon content of showers as a veto to reject cosmic ray initiated showers in ultra-high energy gamma ray astronomy are reported. The possibility of observing very-high energy gamma-ray sources by detecting narrow angle anisotropies in the high energy muon background radiation are considered.

  2. Photoproduction models for total cross section and shower development

    NASA Astrophysics Data System (ADS)

    Cornet, Fernando; Garcia Canal, Carlos; Grau, Agnes; Pancheri, Giulia; Sciutto, Sergio

    2015-08-01

    A model for the total photoproduction cross section, based on the ansatz that resummation of infrared gluons limits the rise induced by QCD minijets in all the total cross-sections, is used to simulate extended air showers initiated by cosmic rays with the AIRES simulation program. The impact on common shower observables, especially those related with muon production, is analysed and compared with the corresponding results obtained with previous photoproduction models.

  3. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

    SciTech Connect

    Aab, Alexander

    2016-01-29

    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method used for cross-checks that indeed we reach nanosecond-scale timing accuracy by this correction. First, we operate a “beacon transmitter” which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA.

  4. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

    DOE PAGES

    Aab, Alexander

    2016-01-29

    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independentmore » method used for cross-checks that indeed we reach nanosecond-scale timing accuracy by this correction. First, we operate a “beacon transmitter” which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA.« less

  5. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

    NASA Astrophysics Data System (ADS)

    The Pierre Auger Collaboration

    2016-01-01

    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a ``beacon transmitter'' which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA.

  6. Observations of steady flux of PeV-energy extensive air showers from Cygnus X-3 during 1984-1986

    NASA Astrophysics Data System (ADS)

    Tonwar, S. C.; Gopalakrishnan, N. V.; Rajeev, M. R.; Sreekantan, B. V.

    1988-07-01

    Data taken with a 24-detector extensive-air-shower (EAS) array, operating at Ooty since June, 1984, have been used to search for excess of EASs of energy greater than 250 TeV from the direction of binary X-ray source Cyg X-3. The data show a time-averaged excess in the number of showers from this direction, over the background determined from other regions of the sky having the same declination. The excess is most prominent among older showers having a flatter lateral distribution. A part of this excess shows up significantly in the phase region, 0.6-0.8 in the 4.8-hr periodicity analysis. These observations correspond to an integral flux of (7.16 + or - 3.15) x 10 to the -13th/sq cm sec at energies greater than 250 TeV and of (1.04 + or - 0.44) x 10 to the -13th/sq cm sec at energies greater than 2.5 PeV. The observations confirm, for the first time, results reported by the Kiel group (Samorski and Stamm, 1983) of a directional excess from the direction of Cyg X-3, without requiring the 4.8-hr periodicity analysis as was necessary in many of the other experiments reporting positive signals. This emphasizes the advantage of good angular resolution for such studies.

  7. An analytical approach to the multiply scattered light in the optical images of the extensive air showers of ultra-high energies

    NASA Astrophysics Data System (ADS)

    Giller, Maria; Śmiałkowski, Andrzej

    2012-08-01

    One of the methods for studying the highest energy cosmic rays is to measure the fluorescence light emitted by the extensive air showers induced by them. To reconstruct a shower cascade curve from measurements of the number of photons arriving from the subsequent shower track elements it is necessary to take into account the multiple scatterings that photons undergo on their way from the shower to the detector. In contrast to the earlier Monte-Carlo work, we present here an analytical method to treat the Rayleigh and Mie scatterings in the atmosphere. The method consists in considering separately the consecutive 'generations' of the scattered light. Starting with a point light source in a uniform medium, we then examine a source in a real atmosphere and finally - a moving source (shower) in it. We calculate the angular distributions of the scattered light superimposed on the not scattered light registered from a shower at a given time. The analytical solutions (although approximate) show how the exact numerical results should be parametrised what we do for the first two generations (the contribution of the higher ones being small). Not allowing for the considered effect may lead to an overestimation of shower primary energy by ˜15% and to an underestimation of the primary particle mass (E0=1019eV with the core distance 25 km and θZ=40°).

  8. Results of a self-triggered prototype system for radio-detection of extensive air showers at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Abreu, P.; Acounis, S.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anti&cbreve; i'c, T.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenir, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Baughman, B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Charrier, D.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, J.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fliescher, S.; Fox, B.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garçon, T.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Ionita, F.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; 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.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Messina, S.; Meurer, C.; Meyhandan, R.; Mi'canovi'c, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Niggemann, T.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Pfendner, C.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, 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.; Rivière, C.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schröder, F.; Schulz, J.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stassi, P.; Stephan, M.; Straub, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Taşcău, O.; Tcaciuc, R.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tkaczyj, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Tridapalli, D. B.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano Garcia, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.

    2012-11-01

    We describe the experimental setup and the results of RAuger, a small radio-antenna array, consisting of three fully autonomous and self-triggered radio-detection stations, installed close to the center of the Surface Detector (SD) of the Pierre Auger Observatory in Argentina. The setup has been designed for the detection of the electric field strength of air showers initiated by ultra-high energy cosmic rays, without using an auxiliary trigger from another detection system. Installed in December 2006, RAuger was terminated in May 2010 after 65 registered coincidences with the SD. The sky map in local angular coordinates (i.e., zenith and azimuth angles) of these events reveals a strong azimuthal asymmetry which is in agreement with a mechanism dominated by a geomagnetic emission process. The correlation between the electric field and the energy of the primary cosmic ray is presented for the first time, in an energy range covering two orders of magnitude between 0.1 EeV and 10 EeV. It is demonstrated that this setup is relatively more sensitive to inclined showers, with respect to the SD. In addition to these results, which underline the potential of the radio-detection technique, important information about the general behavior of self-triggering radio-detection systems has been obtained. In particular, we will discuss radio self-triggering under varying local electric-field conditions.

  9. Electrons, muons and hadrons in extensive air showers and how do they depend on nuclear interaction model, part 2

    NASA Technical Reports Server (NTRS)

    Wrotniak, J. A.; Yodh, G. B.

    1985-01-01

    Some of the results of Monte Carlo simulations of extensive air showers for nuclear interactions models are presented. The most significant part of scaling violation effect is generated by the inclusion of rising cross-section. Among the models considered the lowest value for Eo/N(max) is obtained when rapidly rising cross-section and charge exchange are both included (model R-F01). The value is still 1.38 GeV/electron. Except at the highest energies, the sensitivity to atomic mass of the primary is greater than to specific assumptions about multiple production.

  10. Performance of a local electron density trigger to select extensive air showers at sea level

    NASA Technical Reports Server (NTRS)

    Abbas, T.; Madani, J.; Ashton, F.

    1985-01-01

    Time coincident voltage pulses in the two closely space (1.6m) plastic scintillators were recorded. Most of the recorded events are expeted to be due to electrons in cosmic ray showers whose core fall at some distance from the detectors. This result is confirmed from a measurement of the frequency distribution of the recorded density ratios of the two scintillators.

  11. The small contribution of molecular Bremsstrahlung radiation to the air-fluorescence yield of cosmic ray shower particles

    NASA Astrophysics Data System (ADS)

    Al Samarai, Imen; Deligny, Olivier; Rosado, Jaime

    2016-10-01

    A small contribution of molecular Bremsstrahlung radiation to the air-fluorescence yield in the UV range is estimated based on an approach previously developed in the framework of the radio-detection of showers in the gigahertz frequency range. First, this approach is shown to provide an estimate of the main contribution of the fluorescence yield due to the de-excitation of the C 3Πu electronic level of nitrogen molecules to the B 3Πg one amounting to Y[ 337 ] =(6.05 ± 1.50) MeV-1 at 800 hPa pressure and 293 K temperature conditions, which compares well to previous dedicated works and to experimental results. Then, under the same pressure and temperature conditions, the fluorescence yield induced by molecular Bremsstrahlung radiation is found to be Y[330-400]MBR = 0.10 MeV-1 in the wavelength range of interest for the air-fluorescence detectors used to detect extensive air showers induced in the atmosphere by ultra-high energy cosmic rays. This means that out of ≃175 photons with wavelength between 330 and 400 nm detected by fluorescence detectors, one of them has been produced by molecular Bremsstrahlung radiation. Although small, this contribution is not negligible in regards to the total budget of systematic uncertainties when considering the absolute energy scale of fluorescence detectors.

  12. Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal.

  13. Note on the detection of high energy primary cosmic gamma rays by air shower observation

    NASA Technical Reports Server (NTRS)

    Kasahara, K.; Torii, S.; Yuda, T.

    1985-01-01

    A mountain altitude experiment is planned at Mt. Norikura in Japan to search for point sources of astrophysical high-energy gamma rays in the 10 to the 15th power eV range. The advantages of mountain level observation of IR showers is stressed, especially in the case of high-energy gamma primaries from Cygnus X3 and other similar point sources.

  14. Cosmic ray air shower characteristics in the framework of the parton-based Gribov-Regge model NEXUS

    NASA Astrophysics Data System (ADS)

    Bossard, G.; Drescher, H. J.; Kalmykov, N. N.; Ostapchenko, S.; Pavlov, A. I.; Pierog, T.; Vishnevskaya, E. A.; Werner, K.

    2001-03-01

    The purpose of this paper is twofold: first we want to introduce a new type of hadronic interaction model (NEXUS), which has a much more solid theoretical basis than, for example, presently used models such as QGSJET and VENUS, and ensures therefore a much more reliable extrapolation towards high energies. Secondly, we want to promote an extensive air shower (EAS) calculation scheme, based on cascade equations rather than explicit Monte Carlo simulations, which is very accurate in calculations of main EAS characteristics and extremely fast concerning computing time. We employ the NEXUS model to provide the necessary data on particle production in hadron-air collisions and present the average EAS characteristics for energies 1014-1017 eV. The experimental data of the CASA-BLANCA group are analyzed in the framework of the new model.

  15. Meteor Showers.

    ERIC Educational Resources Information Center

    Kronk, Gary W.

    1988-01-01

    Described are the history, formation, and observing techniques of meteors and comets. Provided are several pictures, diagrams, meteor organizations and publications, and meteor shower observation tables. (YP)

  16. Design and construction of a cosmic ray detector array for the correlation of cosmic ray extensive air showers with lightning strikes

    NASA Astrophysics Data System (ADS)

    Ruse, Aaron Nathan

    The process of lightning initiation is a poorly understood phenomenon. One contending theory suggests that galactic cosmic rays play a role in initiating lightning. This theory is referred to as runaway breakdown (RB). Currently there is no known experimental evidence to support RB. For this thesis, a cosmic ray detector array was designed, constructed, and calibrated in order to gather data to test the RB theory. The goal is to correlate cosmic ray extensive air showers (EAS) with lightning strikes measured by the Oklahoma Lightning Mapping Array (OKLMA). Such a correlation would serve as strong experimental evidence that EAS play an important role in lightning initiation. In order to accomplish this goal, the cosmic ray detectors need to have fast timing for high resolution and be able to distinguish between the secondary hard component (muons) and soft component (electrons/gamma rays) of the EAS. Preliminary data from the detector testing site suggests that the detectors are operating according to the design goals. They are able to resolve individual muon counts and they have measured common phenomena such as radon washout and EAS diurnal variation.

  17. Application of CORSIKA Simulation Code to Study Lateral and Longitudinal Distribution of Fluorescence Light in Cosmic Ray Extensive Air Showers

    NASA Astrophysics Data System (ADS)

    Bagheri, Zahra; Davoudifar, Pantea; Rastegarzadeh, Gohar; Shayan, Milad

    2017-03-01

    In this paper, we used CORSIKA code to understand the characteristics of cosmic ray induced showers at extremely high energy as a function of energy, detector distance to shower axis, number, and density of secondary charged particles and the nature particle producing the shower. Based on the standard properties of the atmosphere, lateral and longitudinal development of the shower for photons and electrons has been investigated. Fluorescent light has been collected by the detector for protons, helium, oxygen, silicon, calcium and iron primary cosmic rays in different energies. So we have obtained a number of electrons per unit area, distance to the shower axis, shape function of particles density, percentage of fluorescent light, lateral distribution of energy dissipated in the atmosphere and visual field angle of detector as well as size of the shower image. We have also shown that location of highest percentage of fluorescence light is directly proportional to atomic number of elements. Also we have shown when the distance from shower axis increases and the shape function of particles density decreases severely. At the first stages of development, shower axis distance from detector is high and visual field angle is small; then with shower moving toward the Earth, angle increases. Overall, in higher energies, the fluorescent light method has more efficiency. The paper provides standard calibration lines for high energy showers which can be used to determine the nature of the particles.

  18. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (Xmax ), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the distributions with predictions from a variety of hadronic interaction models for variations in the composition of the primary cosmic rays and examining the quality of the fit. Regardless of what interaction model is assumed, we find that our data are not well described by a mix of protons and iron nuclei over most of the energy range. Acceptable fits can be obtained when intermediate masses are included, and when this is done consistent results for the proton and iron-nuclei contributions can be found using the available models. We observe a strong energy dependence of the resulting proton fractions, and find no support from any of the models for a significant contribution from iron nuclei. However, we also observe a significant disagreement between the models with respect to the relative contributions of the intermediate components.

  19. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications

    SciTech Connect

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

    2014-12-01

    Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (Xmax), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the distributions with predictions from a variety of hadronic interaction models for variations in the composition of the primary cosmic rays and examining the quality of the fit. Regardless of what interaction model is assumed, we find that our data are not well described by a mix of protons and iron nuclei over most of the energy range. Acceptable fits can be obtained when intermediate masses are included, and when this is done consistent results for the proton and iron-nuclei contributions can be found using the available models. We observe a strong energy dependence of the resulting proton fractions, and find no support from any of the models for a significant contribution from iron nuclei. However, we also observe a significant disagreement between the models with respect to the relative contributions of the intermediate components.

  20. EPA`s clean air power initiative

    SciTech Connect

    Critchfield, L.R.

    1997-12-31

    The Clean Air Power Initiative (CAPI) is a multi-stakeholder project intended to improve air pollution control efforts involving the power generating industry. This paper documents the progress made in the first year of the initiative, which included a number of meetings with interested stakeholders and development and analysis of alternative approaches for more efficient and effective pollution control. The project`s goal is to develop an integrated regulatory strategy or three major pollutants emitted from electric power generators; namely, sulfur dioxide, nitrogen oxides, and, potentially, mercury. Major reductions in these pollutants are expected to be needed to reduce the detrimental health effects of ground-level ozone, fine particles, and hazardous air pollutants and reduce the environmental effects of acidification, eutrophication, ecosystem, crop, and materials damage, and regional haze. The Clean Air Power Initiative has considered, where feasible, new approaches to pollution control that recognize the long-range transport of many air pollutants and the economic benefits of emissions trading. The project was initiated by EPA`s Assistant Administrator for Air and Radiation in 1995. As individual companies develop and implement strategies to participate in more competitive power markets, they could benefit from greater certainty in being able to plan for and reduce costs of future environmental regulations. The EPA is interested in reinventing its regulatory approach to reduce the number, administrative complexity, and cost of its requirements while improving the likelihood of achieving environmental results.

  1. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above 1 017.8 eV

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    We report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 1 017.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for selecting a data sample with minimal sampling bias is described in detail as well as the experimental cross-checks and systematic uncertainties. Furthermore, we discuss the detector acceptance and the resolution of the Xmax measurement and provide parametrizations thereof as a function of energy. The energy dependence of the mean and standard deviation of the Xmax distributions are compared to air-shower simulations for different nuclear primaries and interpreted in terms of the mean and variance of the logarithmic mass distribution at the top of the atmosphere.

  2. Longitudinal development of muons in large air showers studies from the arrival time distributions measured at 900m above sea level

    NASA Technical Reports Server (NTRS)

    Kakimoto, F.; Tsuchimoto, I.; Enoki, T.; Suga, K.; Nishi, K.

    1985-01-01

    The arrival time distributions of muons with energies above 1.0GeV and 0.5GeV have been measured in the Akeno air-shower array to study the longitudinal development of muons in air showers with primary energies in the range 10 to the 17th power to 10 to the 18th power ev. The average rise times of muons with energies above 1.0GeV at large core distances are consistent with those expected from very high multiplicity models and, on the contrary, with those expected from the low multiplicity models at small core distances. This implies that the longitudinal development at atmospheric depth smaller than 500 cm square is very fast and that at larger atmospheric depths is rather slow.

  3. Measurement of the radiation energy in the radio signal of extensive air showers as a universal estimator of cosmic-ray energy

    SciTech Connect

    Aab, Alexander

    2016-06-14

    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 ± 0.7 (stat) ± 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

  4. Measurement of the radiation energy in the radio signal of extensive air showers as a universal estimator of cosmic-ray energy

    DOE PAGES

    Aab, Alexander

    2016-06-14

    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 ± 0.7 (stat) ± 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade ofmore » extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.« less

  5. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above $$10^{17.8}$$ eV

    DOE PAGES

    Aab, Alexander

    2014-12-31

    We report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 1017.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for selecting a data sample with minimal sampling bias is described in detail as well as the experimental cross-checks and systematic uncertainties. Furthermore, we discuss the detector acceptance and the resolution of the Xmax measurement and provide parametrizations thereof as a function of energy. Finally, the energy dependence of the mean and standard deviation of the Xmax distributions are compared to air-shower simulations formore » different nuclear primaries and interpreted in terms of the mean and variance of the logarithmic mass distribution at the top of the atmosphere.« less

  6. Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy.

    PubMed

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

    2016-06-17

    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8±0.7(stat)±6.7(syst)  MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

  7. Radiation Effects Investigations Based on Atmospheric Radiation Model (ATMORAD) Considering GEANT4 Simulations of Extensive Air Showers and Solar Modulation Potential.

    PubMed

    Hubert, Guillaume; Cheminet, Adrien

    2015-07-01

    The natural radiative atmospheric environment is composed of secondary cosmic rays produced when primary cosmic rays hit the atmosphere. Understanding atmospheric radiations and their dynamics is essential for evaluating single event effects, so that radiation risks in aviation and the space environment (space weather) can be assessed. In this article, we present an atmospheric radiation model, named ATMORAD (Atmospheric Radiation), which is based on GEANT4 simulations of extensive air showers according to primary spectra that depend only on the solar modulation potential (force-field approximation). Based on neutron spectrometry, solar modulation potential can be deduced using neutron spectrometer measurements and ATMORAD. Some comparisons between our methodology and standard approaches or measurements are also discussed. This work demonstrates the potential for using simulations of extensive air showers and neutron spectroscopy to monitor solar activity.

  8. Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 ±0.7 (stat)±6.7 (syst) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

  9. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above $10^{17.8}$ eV

    SciTech Connect

    Aab, Alexander

    2014-12-31

    We report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 1017.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for selecting a data sample with minimal sampling bias is described in detail as well as the experimental cross-checks and systematic uncertainties. Furthermore, we discuss the detector acceptance and the resolution of the Xmax measurement and provide parametrizations thereof as a function of energy. Finally, the energy dependence of the mean and standard deviation of the Xmax distributions are compared to air-shower simulations for different nuclear primaries and interpreted in terms of the mean and variance of the logarithmic mass distribution at the top of the atmosphere.

  10. The longitudinal development of muons in cosmic ray air showers at energies 10(15) - 10(17) eV

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The relationship between longitudinal development of muons and conventional equi-intensity cuts is carefully investigated. The development of muons in Extensive Air Showers (EAS) has been calculated using simulation with a scaling violation model at the highest energies and mixed primary composition. Profiles of equi-intensity cuts expected at observation altitudes of 550, 690 and 930/sq cm can fit the observed data very well.

  11. Cosmic ray composition between 10 to the 15th power - 10 to the 17th power eV obtained by air shower experiments

    NASA Technical Reports Server (NTRS)

    Muraki, Y.

    1985-01-01

    Based on the air shower data, the chemical composition of the primary cosmic rays in the energy range 10 to the 15th power - 10 to the 17th power eV was obtained. The method is based on a well known N sub e-N sub mu and N sub e-N sub gamma. The simulation is calibrated by the CERN SPS pp collider results.

  12. Studies of air showers produced by primaries 10(16) eV using a combined scintillation and water-Cerenkov array

    NASA Technical Reports Server (NTRS)

    Brooke, G.; Perrett, J. C.; Watson, A. A.

    1986-01-01

    An array of 8 x 1.0 sq m plastic scintillation counters and 13 water-Cerenkov detectors (1 to 13.5 sq m) were operated at the center of the Haverah Park array to study some features of air showers produced by 10(16) eV primaries. Measurements of the scintillator lateral distribution function, the water-Cerenkov lateral distribution function, and of the distance dependence of the Cerenkov/scintillator ratio are described.

  13. Detection of thermal neutrons with the PRISMA-YBJ array in extensive air showers selected by the ARGO-YBJ experiment

    NASA Astrophysics Data System (ADS)

    Bartoli, B.; Bernardini, P.; Bi, X. J.; Cao, Z.; Catalanotti, S.; Chen, S. Z.; Chen, T. L.; Cui, S. W.; Dai, B. Z.; D'Amone, A.; Danzengluobu; De Mitri, I.; D'Ettorre Piazzoli, B.; Di Girolamo, T.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Iacovacci, M.; Iuppa, R.; Jia, H. Y.; Labaciren; Li, H. J.; Liu, C.; Liu, J.; Liu, M. Y.; Lu, H.; Ma, L. L.; Ma, X. H.; Mancarella, G.; Mari, S. M.; Marsella, G.; Mastroianni, S.; Montini, P.; Ning, C. C.; Perrone, L.; Pistilli, P.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xue, L.; Yang, Q. Y.; Yang, X. C.; Yao, Z. G.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhao, J.; Zhaxiciren; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; Stenkin, Yu. V.; Alekseenko, V. V.; Aynutdinov, V.; Cai, Z. Y.; Guo, X. W.; Liu, Y.; Rulev, V.; Shchegolev, O. B.; Stepanov, V.; Volchenko, V.; Zhang, H.

    2016-08-01

    We report on a measurement of thermal neutrons, generated by the hadronic component of extensive air showers (EAS), by means of a small array of EN-detectors developed for the PRISMA project (PRImary Spectrum Measurement Array), novel devices based on a compound alloy of ZnS(Ag) and 6LiF. This array has been operated within the ARGO-YBJ experiment at the high altitude Cosmic Ray Observatory in Yangbajing (Tibet, 4300 m a.s.l.). Due to the tight correlation between the air shower hadrons and thermal neutrons, this technique can be envisaged as a simple way to estimate the number of high energy hadrons in EAS. Coincident events generated by primary cosmic rays of energies greater than 100 TeV have been selected and analyzed. The EN-detectors have been used to record simultaneously thermal neutrons and the air shower electromagnetic component. The density distributions of both components and the total number of thermal neutrons have been measured. The correlation of these data with the measurements carried out by ARGO-YBJ confirms the excellent performance of the EN-detector.

  14. Electronics and data acquisition system of the extensive air shower detector array at the University of Puebla

    NASA Astrophysics Data System (ADS)

    Perez, E.; Salazar, H.; Villasenor, L.; Martinez, O.; Conde, R.; Murrieta, T.

    Field programmable gate arrays (FPGAs) are playing an increasing role in DAQ systems in cosmic ray experiments due to their high speed and integration and their low cost and low power comsumption. In this paper we describe in detail the new electronics and data acquisition system based on FPGA boards of the extensive air shower detector array built in the Campus of the University of Puebla. The purpose of this detector array is to measure the energy and arrival direction of primary cosmic rays with energies around 1015 eV. The array consists of 10 liquid scintillator detectors and 6 water Cherenkov detectors (of 1.86 m2 cross section), distributed in a square grid with a detector spacing of 20 m over an area of 4000 m2. The electronics described also makes use of analog to digital converters with a resolution of 10 bits and sampling speeds of 100 MS/s to digitize the PMT signals. We also discuss the advantages of discriminating the PMT signals inside the FPGAs with respect to the conventional use of dedicated discrimination circuits.

  15. Numerical simulations of compact intracloud discharges as the Relativistic Runaway Electron Avalanche-Extensive Air Shower process

    NASA Astrophysics Data System (ADS)

    Arabshahi, S.; Dwyer, J. R.; Nag, A.; Rakov, V. A.; Rassoul, H. K.

    2014-01-01

    Compact intracloud discharges (CIDs) are sources of the powerful, often isolated radio pulses emitted by thunderstorms. The VLF-LF radio pulses are called narrow bipolar pulses (NBPs). It is still not clear how CIDs are produced, but two categories of theoretical models that have previously been considered are the Transmission Line (TL) model and the Relativistic Runaway Electron Avalanche-Extensive Air Showers (RREA-EAS) model. In this paper, we perform numerical calculations of RREA-EASs for various electric field configurations inside thunderstorms. The results of these calculations are compared to results from the other models and to the experimental data. Our analysis shows that different theoretical models predict different fundamental characteristics for CIDs. Therefore, many previously published properties of CIDs are highly model dependent. This is because of the fact that measurements of the radiation field usually provide information about the current moment of the source, and different physical models with different discharge currents could have the same current moment. We have also found that although the RREA-EAS model could explain the current moments of CIDs, the required electric fields in the thundercloud are rather large and may not be realistic. Furthermore, the production of NBPs from RREA-EAS requires very energetic primary cosmic ray particles, not observed in nature. If such ultrahigh-energy particles were responsible for NBPs, then they should be far less frequent than is actually observed.

  16. Northern Sky Galactic Cosmic Ray Anisotropy between 10 and 1000 TeV with the Tibet Air Shower Array

    NASA Astrophysics Data System (ADS)

    Amenomori, M.; Bi, X. J.; Chen, D.; Chen, T. L.; Chen, W. Y.; Cui, S. W.; Danzengluobu; Ding, L. K.; Feng, C. F.; Feng, Zhaoyang; Feng, Z. Y.; Gou, Q. B.; Guo, Y. Q.; He, H. H.; He, Z. T.; Hibino, K.; Hotta, N.; Hu, Haibing; Hu, H. B.; Huang, J.; Jia, H. Y.; Jiang, L.; Kajino, F.; Kasahara, K.; Katayose, Y.; Kato, C.; Kawata, K.; Kozai, M.; Labaciren; Le, G. M.; Li, A. F.; Li, H. J.; Li, W. J.; Liu, C.; Liu, J. S.; Liu, M. Y.; Lu, H.; Meng, X. R.; Miyazaki, T.; Mizutani, K.; Munakata, K.; Nakajima, T.; Nakamura, Y.; Nanjo, H.; Nishizawa, M.; Niwa, T.; Ohnishi, M.; Ohta, I.; Ozawa, S.; Qian, X. L.; Qu, X. B.; Saito, T.; Saito, T. Y.; Sakata, M.; Sako, T. K.; Shao, J.; Shibata, M.; Shiomi, A.; Shirai, T.; Sugimoto, H.; Takita, M.; Tan, Y. H.; Tateyama, N.; Torii, S.; Tsuchiya, H.; Udo, S.; Wang, H.; Wu, H. R.; Xue, L.; Yamamoto, Y.; Yamauchi, K.; Yang, Z.; Yuan, A. F.; Yuda, T.; Zhai, L. M.; Zhang, H. M.; Zhang, J. L.; Zhang, X. Y.; Zhang, Y.; Zhang, Yi; Zhang, Ying; Zhaxisangzhu; Zhou, X. X.; The Tibet ASγ Collaboration

    2017-02-01

    We report on the analysis of the 10–1000 TeV large-scale sidereal anisotropy of Galactic cosmic rays (GCRs) with the data collected by the Tibet Air Shower Array from 1995 October to 2010 February. In this analysis, we improve the energy estimate and extend the decl. range down to ‑30°. We find that the anisotropy maps above 100 TeV are distinct from that at a multi-TeV band. The so-called tail-in and loss-cone features identified at low energies get less significant, and a new component appears at ∼100 TeV. The spatial distribution of the GCR intensity with an excess (7.2σ pre-trial, 5.2σ post-trial) and a deficit (‑5.8σ pre-trial) are observed in the 300 TeV anisotropy map, in close agreement with IceCube’s results at 400 TeV. Combining the Tibet results in the northern sky with IceCube’s results in the southern sky, we establish a full-sky picture of the anisotropy in hundreds of TeV band. We further find that the amplitude of the first order anisotropy increases sharply above ∼100 TeV, indicating a new component of the anisotropy. All these results may shed new light on understanding the origin and propagation of GCRs.

  17. An upper limit of muon flux of energies above 100 TeV determined from horizontal air showers observed at Akeno

    NASA Technical Reports Server (NTRS)

    Nagano, M.; Yoshii, H.; Hara, T.; Kamata, K.; Kawaguchi, S.; Kifune, T.

    1985-01-01

    Muon energy spectrum above 100 TeV was determined by observing the extensive air showers (EAS) from the horizontal direction (HAS). No definite muon originated shower of sizes above 100,000 and zenith angles above 60 deg was observed. The upper limits of HAS intensity is 5x10/12 m/2 s/1 sn/1 above 100,000. It is indicated that the upper limit of muon flux above 100 TeV is about 1.3x10/8 m/2 s/1 sr/1 and is in agreement with that expected from the primary spectrum with a knee assuming scaling in the fragmentation region and 40% protons in the primary beam. The critical energy at which muon flux from prompt processes take over that from the conventional process is higher than 100 Tev at horizontal direction.

  18. Determining human exposure and sensory detection of odorous compounds released during showering.

    PubMed

    Omür-Ozbek, Pinar; Gallagher, Daniel L; Dietrich, Andrea M

    2011-01-15

    Modeling of human exposure to aqueous algal odorants geosmin (earthy), 2-methylisoborneol (musty), and (trans,cis)-2,6-nonadienal (cucumber, fishy), and the solvent trichloroethylene (sweet chemical), was investigated to improve the understanding of water-air transfer by including humans as sensors to detect contaminants. A mass-transfer model was employed to determine indoor air concentrations when water was used for showering under varying conditions (shower stall volume, water and air flow rate, temperature, aqueous odorant concentration, shower duration). Statistical application of multiple linear regression and tree regression were employed to determine critical model parameters. The model predicted that concentrations detectable to the human senses were controlled by temperature, odor threshold, and aqueous concentration for the steady-state model, whereas shower volume, air flow, and water flow are also important for the dynamic model and initial detection of the odorant immediately after the showering is started. There was excellent agreement of model predictions with literature data for human perception of algal odorants in their homes and complaints to water utilities. TCE performed differently than the algal odorants due to its higher Henry's law constant, in spite of similar gas and liquid diffusivities. The use of nontoxic odorants offers an efficient tool to calibrate indoor air/water shower models.

  19. TeV γ-ray astronomy with ground-based air-shower arrays

    NASA Astrophysics Data System (ADS)

    Mostafá, Miguel A.

    2016-07-01

    The TeV energy band is a very exciting window into the origin of high energy cosmic radiation, particle acceleration, and the annihilation of dark matter particles. Above a few hundred GeV, ground-based experiments of very large effective areas open a new domain to study extragalactic sources at intermediate redshifts, galaxy clusters, gamma ray bursts, AGN and their flaring states, extended sources and galactic diffuse emission, and to indirect searches for dark matter. In particular, ground arrays of particle detectors -that operate with high duty cycles and large fields of view- can extend to multi-TeV energies the measurements made with experiments on satellites, and complement the observations done with air Cherenkov telescopes on the ground. Key science goals of ground arrays include performing unbiased all-sky surveys, monitoring of transient events from known (and unknown) sources, and detecting extended regions of diffuse emission. In this paper, the status and most recent results from ARGO-YBJ, Tibet AS, HAWC, and LHAASO are presented.

  20. The composition of cosmic rays near the Bend (10 to the 15th power eV) from a study of muons in air showers at sea level

    NASA Technical Reports Server (NTRS)

    Goodman, J. A.; Gupta, S. C.; Freudenreich, H. T.; Sivaprasad, K.; Tonwar, S. C.; Yodh, G. B.; Ellsworth, R. W.; Goodman, M. C.; Bogert, M. C.; Burnstein, R.

    1985-01-01

    The distribution of muons near shower cores was studied at sea level at Fermilab using the E594 neutrino detector to sample the muon with E testing 3 GeV. These data are compared with detailed Monte Carlo simulations to derive conclusions about the composition of cosmic rays near the bend in the all particle spectrum. Monte Carlo simulations generating extensive air showers (EAS) with primary energy in excess of 50 TeV are described. Each shower record contains details of the electron lateral distribution and the muon and hadron lateral distributions as a function of energy, at the observation level of 100g/cm. The number of detected electrons and muons in each case was determined by a Poisson fluctuation of the number incident. The resultant predicted distribution of muons, electrons, the rate events are compared to those observed. Preliminary results on the rate favor a heavy primary dominated cosmic ray spectrum in energy range 50 to 1000 TeV.

  1. Laser-initiated ordnance for air-to-air missiles

    NASA Technical Reports Server (NTRS)

    Sumpter, David R.

    1993-01-01

    McDonnell Douglas Missile Systems Company (MDMSC) has developed a laser ignition subsystem (LIS) for air-to-air missile applications. The MDMSC subsystem is designed to activate batteries, unlock fins, and sequence propulsion system events. The subsystem includes Pyro Zirconium Pump (PZP) lasers, mechanical Safe & Arm, fiber-optic distribution system, and optically activated pyrotechnic devices (initiators, detonators, and thermal batteries). The LIS design has incorporated testability features for the laser modules, drive electronics, fiber-optics, and pyrotechnics. Several of the LIS have been fabricated and have supported thermal battery testing, integral rocket ramjet testing, and have been integrated into integral rocket ramjet flight test vehicles as part of the flight control subsystem.

  2. Underground water Cherenkov muon detector array with the Tibet air shower array for gamma-ray astronomy in the 100 TeV region

    NASA Astrophysics Data System (ADS)

    Amenomori, M.; Ayabe, S.; Bi, X. J.; Chen, D.; Cui, S. W.; Danzengluobu; Ding, L. K.; Ding, X. H.; Feng, C. F.; Feng, Zhaoyang; Feng, Z. Y.; Gao, X. Y.; Geng, Q. X.; Guo, H. W.; He, H. H.; He, M.; Hibino, K.; Hotta, N.; Hu, Haibing; Hu, H. B.; Huang, J.; Huang, Q.; Jia, H. Y.; Kajino, F.; Kasahara, K.; Katayose, Y.; Kato, C.; Kawata, K.; Labaciren; Le, G. M.; Li, A. F.; Li, J. Y.; Lu, H.; Lu, S. L.; Meng, X. R.; Mizutani, K.; Mu, J.; Munakata, K.; Nagai, A.; Nanjo, H.; Nishizawa, M.; Ohnishi, M.; Ohta, I.; Onuma, H.; Ouchi, T.; Ozawa, S.; Ren, J. R.; Saito, T.; Saito, T. Y.; Sakata, M.; Sako, T. K.; Sasaki, T.; Shibata, M.; Shiomi, A.; Shirai, T.; Sugimoto, H.; Takita, M.; Tan, Y. H.; Tateyama, N.; Torii, S.; Tsuchiya, H.; Udo, S.; Wang, B.; Wang, H.; Wang, X.; Wang, Y. G.; Wu, H. R.; Xue, L.; Yamamoto, Y.; Yan, C. T.; Yang, X. C.; Yasue, S.; Ye, Z. H.; Yu, G. C.; Yuan, A. F.; Yuda, T.; Zhang, H. M.; Zhang, J. L.; Zhang, N. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Yi; Zhaxisangzhu; Zhou, X. X.

    2007-06-01

    We propose to build a large water-Cherenkov-type muon-detector array (Tibet MD array) around the 37 000 m2 Tibet air shower array (Tibet AS array) already constructed at 4300 m above sea level in Tibet, China. Each muon detector is a waterproof concrete pool, 6 m wide × 6 m long × 1.5 m deep in size, equipped with a 20 inch-in-diameter PMT. The Tibet MD array consists of 240 muon detectors set up 2.5 m underground. Its total effective area will be 8640 m2 for muon detection. The Tibet MD array will significantly improve gamma-ray sensitivity of the Tibet AS array in the 100 TeV region (10 1000 TeV) by means of gamma/hadron separation based on counting the number of muons accompanying an air shower. The Tibet AS+MD array will have the sensitivity to gamma rays in the 100 TeV region by an order of magnitude better than any other previous existing detectors in the world.

  3. The Air Quality Model Evaluation International Initiative ...

    EPA Pesticide Factsheets

    This presentation provides an overview of the Air Quality Model Evaluation International Initiative (AQMEII). It contains a synopsis of the three phases of AQMEII, including objectives, logistics, and timelines. It also provides a number of examples of analyses conducted through AQMEII with a particular focus on past and future analyses of deposition. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and transport, and support environmental diagnostics/forensics with input from multiple data sources. It also develops media- and receptor-specific models, process models, and decision support tools for use both within and outside of EPA.

  4. Radio signals from very large showers

    NASA Technical Reports Server (NTRS)

    Suga, K.; Kakimoto, F.; Nishi, K.

    1985-01-01

    Radio signals from air showers with electron sizes in the range 1 x 10 to the 7th power to 2 x 10 to the 9th power were detected at 50kHz, 170kHz, and 1,647kHz at large core distances in the Akeno square kilometers air-shower array. The field strength is higher than that expected from any mechanisms hitherto proposed.

  5. SEARCH FOR GAMMA RAYS ABOVE 100 TeV FROM THE CRAB NEBULA WITH THE TIBET AIR SHOWER ARRAY AND THE 100 m{sup 2} MUON DETECTOR

    SciTech Connect

    Amenomori, M.; Bi, X. J.; Chen, W. Y.; Ding, L. K.; Feng, Zhaoyang; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, H. B.; Huang, J.; Chen, D.; Chen, T. L.; Danzengluobu; Hu, Haibing; Cui, S. W.; He, Z. T.; Feng, C. F.; Feng, Z. Y.; Hibino, K.; Hotta, N.; Collaboration: Tibet ASγ Collaboration; and others

    2015-11-10

    A 100 m{sup 2} muon detector (MD) was successfully constructed under the existing Tibet air shower (AS) array in the late fall of 2007. The sensitivity of the Tibet AS array to cosmic gamma rays can be improved by selecting muon-poor events with the MD. Our MC simulation of the MD response reasonably agrees with the experimental data in terms of the charge distribution for one-muon events and the background rejection power. Using the data collected by the Tibet AS array and the 100 m{sup 2} MD taken from 2008 March to 2010 February, we search for continuous gamma-ray emission from the Crab Nebula above ∼100 TeV. No significant excess is found, and the most stringent upper limit is obtained above 140 TeV.

  6. Perspective of detecting very high energy gamma-ray emission from active galactic nuclei with Large High Altitude Air Shower Observatory (LHAASO)

    NASA Astrophysics Data System (ADS)

    Zhao, Yi; Yuan, Qiang; Bi, Xiao-Jun; Zhu, Feng-Rong; Jia, Huan-Yu

    2016-10-01

    The detectability of active galactic nuclei (AGN), a major class of γ-ray emitters in the sky, by the newly planned Chinese project, Large High Altitude Air Shower Observatory (LHAASO), is investigated. The expectation is primarily based on the AGN catalog of Fermi Large Area Telescope (Fermi-LAT), with an extrapolation to the very high energy (VHE) range taking into account the absorption effect by the extragalactic background light (EBL). It is found that LHAASO may have the potential to detect more than several tens of the Fermi detected AGN, basically BL Lacertaes, with one-year sky survey. The capability of measuring the energy spectrum and light curve are also discussed.

  7. On the possibility to discriminate the mass of the primary cosmic ray using the muon arrival times from extensive air showers: Application for Pierre Auger Observatory

    SciTech Connect

    Arsene, N.; Rebel, H.; Sima, O.

    2012-11-20

    In this paper we study the possibility to discriminate the mass of the primary cosmic ray by observing the muon arrival times in ground detectors. We analyzed extensive air showers (EAS) induced by proton and iron nuclei with the same energy 8 Multiplication-Sign 10{sup 17} eV simulated with CORSIKA, and analyzed the muon arrival times at ground measured by the infill array detectors of the Pierre Auger Observatory (PAO). From the arrival times of the core and of the muons the atmospheric depth of muon generation locus is evaluated. The results suggest a potential mass discrimination on the basis of muon arrival times and of the reconstructed atmospheric depth of muon production. An analysis of a larger set of CORSIKA simulations carried out for primary energies above 10{sup 18} eV is in progress.

  8. Search for 100 TeV gamma rays from the Crab Nebula with the Tibet Air Shower Array and the 100 m2 muon detector

    NASA Astrophysics Data System (ADS)

    Sako, Takashi

    2016-07-01

    The 100 m ^{2} muon detector (MD) was constructed under the Tibet air shower (AS) array in the late autumn of 2007. By selecting muon-poor events with the MD, the sensitivity of the Tibet AS array to cosmic gamma rays can be improved. Our MC simulation of the MD response is in reasonable agreement with the experimental data, with regard to the charge distribution for one-muon events and the background rejection power. Using the data taken from 2008 March to 2010 February by the Tibet AS array and the 100 m ^{2} MD, we search for continuous 100 TeV gamma-ray emission from the Crab Nebula. No significant excess is detected, and the world's best upper limit is obtained above 140 TeV.

  9. Search for Gamma Rays above 100 TeV from the Crab Nebula with the Tibet Air Shower Array and the 100 m2 muon Detector

    NASA Astrophysics Data System (ADS)

    Amenomori, M.; Bi, X. J.; Chen, D.; Chen, T. L.; Chen, W. Y.; Cui, S. W.; Danzengluobu; Ding, L. K.; Feng, C. F.; Feng, Zhaoyang; Feng, Z. Y.; Gou, Q. B.; Guo, Y. Q.; He, H. H.; He, Z. T.; Hibino, K.; Hotta, N.; Hu, Haibing; Hu, H. B.; Huang, J.; Jia, H. Y.; Jiang, L.; Kajino, F.; Kasahara, K.; Katayose, Y.; Kato, C.; Kawata, K.; Kozai, M.; Labaciren; Le, G. M.; Li, A. F.; Li, H. J.; Li, W. J.; Liu, C.; Liu, J. S.; Liu, M. Y.; Lu, H.; Meng, X. R.; Miyazaki, T.; Mizutani, K.; Munakata, K.; Nakajima, T.; Nakamura, Y.; Nanjo, H.; Nishizawa, M.; Niwa, T.; Ohnishi, M.; Ohta, I.; Ozawa, S.; Qian, X. L.; Qu, X. B.; Saito, T.; Saito, T. Y.; Sakata, M.; Sako, T. K.; Shao, J.; Shibata, M.; Shiomi, A.; Shirai, T.; Sugimoto, H.; Takita, M.; Tan, Y. H.; Tateyama, N.; Torii, S.; Tsuchiya, H.; Udo, S.; Wang, H.; Wu, H. R.; Xue, L.; Yamamoto, Y.; Yamauchi, K.; Yang, Z.; Yasue, S.; Yuan, A. F.; Yuda, T.; Zhai, L. M.; Zhang, H. M.; Zhang, J. L.; Zhang, X. Y.; Zhang, Y.; Zhang, Yi; Zhang, Ying; Zhaxisangzhu; Zhou, X. X.; Tibet ASγ Collaboration

    2015-11-01

    A 100 m2 muon detector (MD) was successfully constructed under the existing Tibet air shower (AS) array in the late fall of 2007. The sensitivity of the Tibet AS array to cosmic gamma rays can be improved by selecting muon-poor events with the MD. Our MC simulation of the MD response reasonably agrees with the experimental data in terms of the charge distribution for one-muon events and the background rejection power. Using the data collected by the Tibet AS array and the 100 m2 MD taken from 2008 March to 2010 February, we search for continuous gamma-ray emission from the Crab Nebula above ˜100 TeV. No significant excess is found, and the most stringent upper limit is obtained above 140 TeV.

  10. CMAQ Involvement in Air Quality Model Evaluation International Initiative

    EPA Pesticide Factsheets

    Description of Air Quality Model Evaluation International Initiative (AQMEII). Different chemical transport models are applied by different groups over North America and Europe and evaluated against observations.

  11. Exemplary Clean Air and Climate Initiatives Win EPA Honors

    EPA Pesticide Factsheets

    WASHINGTON - This week, the U.S. Environmental Protection Agency (EPA) is honoring seven projects for their work on clean air and climate initiatives, including investment in alternative fuel vehicle fleets, business partnerships to reduce pollutant

  12. The Air Quality Model Evaluation International Initiative (AQMEII)

    EPA Science Inventory

    This presentation provides an overview of the Air Quality Model Evaluation International Initiative (AQMEII). It contains a synopsis of the three phases of AQMEII, including objectives, logistics, and timelines. It also provides a number of examples of analyses conducted through ...

  13. Mechanism of UES relaxation initiated by gastric air distension.

    PubMed

    Lang, Ivan M; Medda, Bidyut K; Shaker, Reza

    2014-08-15

    The aim of this study was to determine the mechanism of initiation of transient upper esophageal sphincter relaxation (TUESR) caused by gastric air distension. Cats (n = 31) were decerebrated, EMG electrodes were placed on the cricopharyngeus, a gastric fistula was formed, and a strain gauge was sewn on the lower esophageal sphincter (n = 8). Injection of air (114 ± 13 ml) in the stomach caused TUESR (n = 18) and transient lower esophageal sphincter relaxation (TLESR, n = 6), and this effect was not significantly (P > 0.05) affected by thoracotomy. Free air or bagged air (n = 6) activated TLESR, but only free air activated TUESR. Closure of the gastroesophageal junction blocked TUESR (9/9), but not TLESR (4/4), caused by air inflation of the stomach. Venting air from distal esophagus during air inflation of the stomach prevented TUESR (n = 12) but did not prevent air escape from the stomach to the esophagus (n = 4). Rapid injection of air on the esophageal mucosa always caused TUESR (9/9) but did not always (7/9) cause an increase in esophageal pressure. The time delay between the TUESR and the rapid air pulse was significantly more variable (P < 0.05) than the time delay between the rapid air pulse and the rise in esophageal pressure. We concluded that the TUESR caused by gastric air distension is dependent on air escape from the stomach, which stimulates receptors in the esophagus, but is not dependent on distension of the stomach or esophagus, or the TLESR. Therefore, the TUESR caused by gastric air distension is initiated by stimulation of receptors in the esophageal mucosa.

  14. Canada-wide standards and innovative transboundary air quality initiatives.

    PubMed

    Barton, Jane

    2008-01-01

    Canada's approach to air quality management is one that has brought with it opportunities for the development of unique approaches to risk management. Even with Canada's relatively low levels of pollution, science has demonstrated clearly that air quality and ecosystem improvements are worthwhile. To achieve change and address air quality in Canada, Canadian governments work together since, under the constitution, they share responsibility for the environment. At the same time, because air pollution knows no boundaries, working with the governments of other nations is essential to get results. International cooperation at all levels provides opportunities with potential for real change. Cooperation within transboundary airsheds is proving a fruitful source of innovative opportunities to reduce cross-border barriers to air quality improvements. In relation to the NERAM Colloquium objective to establish principles for air quality management based on the identification of international best practice in air quality policy development and implementation, Canada has developed, both at home and with the United States, interesting air management strategies and initiatives from which certain lessons may be taken that could be useful in other countries with similar situations. In particular, the Canada-wide strategies for smog and acid rain were developed by Canadian governments, strategies that improve and protect air quality at home, while Canada-U.S. transboundary airshed projects provide examples of international initiatives to improve air quality.

  15. Extensive air shower Monte Carlo modeling at the ground and aircraft flight altitude in the South Atlantic Magnetic Anomaly and comparison with neutron measurements

    NASA Astrophysics Data System (ADS)

    Pazianotto, M. T.; Cortés-Giraldo, M. A.; Federico, C. A.; Hubert, G.; Gonçalez, O. L.; Quesada, J. M.; Carlson, B. V.

    2017-02-01

    Modeling cosmic-ray-induced particle fluxes in the atmosphere is very important for developing many applications in aeronautics, space weather and on ground experimental arrangements. There is a lack of measurements and modeling at flight altitude and on ground in the South Atlantic Magnetic Anomaly. In this work we have developed an application based on the Geant4 toolkit called gPartAt that is aimed at the analysis of extensive air shower particle spectra. Another application has been developed using the MCNPX code with the same approach in order to evaluate the models and nuclear data libraries used in each application. Moreover, measurements were performed to determine the ambient dose equivalent rate of neutrons at flight altitude in different regions and dates in the Brazilian airspace; these results were also compared with the simulations. The results from simulations of the neutron spectra at ground level were also compared to data from a neutron spectrometer in operation since February 2015 at the Pico dos Dias Observatory in Brazil, at 1864 m above sea level, as part of a collaboration between the Institute for Advanced Studies (IEAv) and the French Aerospace Lab (ONERA). This measuring station is being operated with support from the National Astrophysics Laboratory (LNA). The modeling approaches were also compared to the AtmoRad computational platform, QARM, EXPACS codes and with measurements of the neutron spectrum taken in 2009 at the Pico dos Dias Observatory.

  16. Splitting Neutrino masses and Showering into Sky

    NASA Astrophysics Data System (ADS)

    Fargion, D.; D'Armiento, D.; Lanciano, O.; Oliva, P.; Iacobelli, M.; de Sanctis Lucentini, P. G.; Grossi, M.; de Santis, M.

    2007-06-01

    Neutrino masses might be as light as a few time the atmospheric neutrino mass splitting. The relic cosmic neutrinos may cluster in wide Dark Hot Local Group Halo. High Energy ZeV cosmic neutrinos (in Z-Showering model) might hit relic ones at each mass in different resonance energies in our nearby Universe. This non-degenerated density and energy must split UHE Z-boson secondaries (in Z-Burst model) leading to multi injection of UHECR nucleons within future extreme AUGER energy. Secondaries of Z-Burst as neutral gamma, below a few tens EeV are better surviving local GZK cut-off and they might explain recent Hires BL-Lac UHECR correlations at small angles. A different high energy resonance must lead to Glashow's anti-neutrino showers while hitting electrons in matter. In water and ice it leads to isotropic light explosions. In air, Glashow's anti-neutrino showers lead to collimated and directional air-showers offering a new Neutrino Astronomy. Because of neutrino flavor mixing, astrophysical energetic tau neutrino above tens GeV must arise over atmospheric background. At TeV range is difficult to disentangle tau neutrinos from other atmospheric flavors. At greater energy around PeV, Tau escaping mountains and Earth and decaying in flight are effectively showering in air sky. These Horizontal showering is splitting by geomagnetic field in forked shapes. Such air-showers secondaries release amplified and beamed gamma bursts (like observed TGF), made also by muon and electron pair bundles, with their accompanying rich Cherenkov flashes. Also planet's largest (Saturn, Jupiter) atmosphere limbs offer an ideal screen for UHE GZK and Z-burst tau neutrino, because their largest sizes. Titan thick atmosphere and small radius are optimal for discovering up-going resonant Glashow resonant anti-neutrino electron showers. Detection from Earth of Tau, anti-Tau, anti-electron neutrino induced Air-showers by twin Magic Telescopes on top mountains, or space based detection on

  17. Multidimensional analysis of data obtained in experiments with X-ray emulsion chambers and extensive air showers

    NASA Technical Reports Server (NTRS)

    Chilingaryan, A. A.; Galfayan, S. K.; Zazyan, M. Z.; Dunaevsky, A. M.

    1985-01-01

    Nonparametric statistical methods are used to carry out the quantitative comparison of the model and the experimental data. The same methods enable one to select the events initiated by the heavy nuclei and to calculate the portion of the corresponding events. For this purpose it is necessary to have the data on artificial events describing the experiment sufficiently well established. At present, the model with the small scaling violation in the fragmentation region is the closest to the experiments. Therefore, the treatment of gamma families obtained in the Pamir' experiment is being carried out at present with the application of these models.

  18. Bioventing Field Initiative at Keesler Air Force Base, Mississippi

    DTIC Science & Technology

    2007-11-02

    This report describes the activities conducted at Keesler AFB, Mississippi, as part of the Bioventing Field initiative for the U.S. Air Force Center...and installation of bioventing systems. Each site at the base is discussed individually, followed by a description of site activities at the...background area. The purpose of this Bioventing Field initiative is to measure the soil gas permeability and microbial activity at a contaminated site in

  19. The Mbale meteorite shower

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.; Betlem, H.; Betlem, J.; Barifaijo, E.; Schluter, T.; Hampton, C.; Laubenstein, M.; Kunz, J.; Heusser, G.

    1994-03-01

    On 1992 August 14 at 12:40 UTC, an ordinary chondrite of type L5/6 entered the atmosphere over Mbale, Uganda, broke up, and caused a strewn field of size 3 x 7 km. Shortly after the fall, an expedition gathered eye witness accounts and located the position of 48 impacts of masses between 0.19 and 27.4 kg. Short-lived radionuclide data were measured for two specimens, one of which was only 12 days after the fall. Subsequent recoveries of fragements has resulted in a total of 863 mass estimates by 1993 October. The surfaces of all fragments contain fusion crust. The meteorite shower caused some minor inconveniences. Most remarkably, a young boy was hit on the head by a small specimen. The data interpreted as to indicate that the meteorite had an initial mass between 400-1000 kg (most likely approximately 1000 kg) and approached Mbale from AZ = 185 +/- 15, H = 55 +/- 15, and Vinfinity = 13.5 +/- 1.5/s. Orbital elements are given. Fragmentation of the initial mass started probably above 25 km altitude, but the final catastrophic breakup occurred at an altitude of 10-14 km. An estimated 190 +/- 40 kg reached the Earth's surface minutes after the final breakup of which 150 kg of material has been recovered.

  20. The Mbale meteorite shower

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Betlem, Hans; Betlem, Jan; Barifaijo, Erasmus; Schluter, Thomas; Hampton, Craig; Laubenstien, Matthias; Kunz, Joachim; Heusser, Gerd

    1994-01-01

    On 1992 August 14 at 12:40 UTC, an ordinary chondrite of type L5/6 entered the atmosphere over Mbale, Uganda, broke up, and caused a strewn field of size 3 x 7 km. Shortly after the fall, an expedition gathered eye witness accounts and located the position of 48 impacts of masses between 0.19 and 27.4 kg. Short-lived radionuclide data were measured for two specimens, one of which was only 12 days after the fall. Subsequent recoveries of fragements has resulted in a total of 863 mass estimates by 1993 October. The surfaces of all fragments contain fusion crust. The meteorite shower caused some minor inconveniences. Most remarkably, a young boy was hit on the head by a small specimen. The data interpreted as to indicate that the meteorite had an initial mass between 400-1000 kg (most likely approximately 1000 kg) and approached Mbale from AZ = 185 +/- 15, H = 55 +/- 15, and V(sub infinity) = 13.5 +/- 1.5/s. Orbital elements are given. Fragmentation of the initial mass started probably above 25 km altitude, but the final catastrophic breakup occurred at an altitude of 10-14 km. An estimated 190 +/- 40 kg reached the Earth's surface minutes after the final breakup of which 150 kg of material has been recovered.

  1. Learning at Air Navigation Services after Initial Training

    ERIC Educational Resources Information Center

    Teperi, Anna-Maria; Leppanen, Anneli

    2010-01-01

    Purpose: This study aims to find out the means used for individual, group and organizational learning at work at one air navigation service provider after the initial training period. The study also aims to find out what practices need to be improved to enhance learning at work. Design/methodology/approach: The data for the study were collected…

  2. Bioventing Field Initiative at Robins Air Force Base, Georgia

    DTIC Science & Technology

    2007-11-02

    This report describes the activities conducted at three sites at Robins Air Force Base (AFB), Georgia, as part of the Bioventing Field initiative for...respiration test, and installation of a bioventing system. The specific objectives of this task are described in the following section. The test sites at the

  3. Air transport of plutonium metal: content expansion initiative for the plutonium air transportable (PAT01) packaging

    SciTech Connect

    Caviness, Michael L; Mann, Paul T

    2010-01-01

    The National Nuclear Security Administration (NNSA) has submitted an application to the Nuclear Regulatory Commission (NRC) for the air shipment of plutonium metal within the Plutonium Air Transportable (PAT-1) packaging. The PAT-1 packaging is currently authorized for the air transport of plutonium oxide in solid form only. The INMM presentation will provide a limited overview of the scope of the plutonium metal initiative and provide a status of the NNSA application to the NRC.

  4. Upgrading and testing the 3D reconstruction of gamma-ray air showers as observed with an array of Cherenkov telescopes

    SciTech Connect

    Naumann-Godo, Melitta; Degrange, Bernard

    2008-12-24

    Stereoscopic arrays of Imaging Cherenkov Telescopes allow to reconstruct gamma-ray-induced showers in 3 dimensions. An analysis method based on a simple 3D-model of electromagnetic showers and implemented in the framework of the H.E.S.S. experiment was recently improved by an additional quality criterion which reduces the background contamination by a factor of about 2 in the case of extended sources, while hardly affecting gamma-ray selection efficiency. Moreover, the dramatic flares of PKS 2155-304 in July 2006, which provided H.E.S.S. data with an almost pure gamma-ray sample, offered the unique opportunity of a precision test of the 3D-reconstruction method as well as of the H.E.S.S. simulations used in its calibration. An agreement at a few percent level is found between data and simulations for the distributions of all 3D shower parameters.

  5. The All-Particle Spectrum of Primary Cosmic Rays in the Wide Energy Range from 10{sup 14} to 10{sup 17} eV Observed with the Tibet-III Air-Shower Array

    SciTech Connect

    Amenomori, M.; Bi, X. J.; Ding, L. K.; Feng, Zhaoyang; He, H. H.; Hu, H. B.; Chen, D.; Cui, S. W.; Danzengluobu; Ding, X. H.; Guo, H. W.; Hu, Haibing; Fan, C.; Feng, C. F.; He, M.; Feng, Z. Y.; Gao, X. Y.; Geng, Q. X.; Hibino, K.; Hotta, N.

    2008-05-10

    We present an updated all-particle energy spectrum of primary cosmic rays in a wide range from 10{sup 14} to 10{sup 17} eV using 5.5 x 10{sup 7} events collected from 2000 November through 2004 October by the Tibet-III air-shower array located 4300 m above sea level (an atmospheric depth of 606 g cm{sup -2}). The size spectrum exhibits a sharp knee at a corresponding primary energy around 4 PeV. This work uses increased statistics and new simulation calculations for the analysis. We discuss our extensive Monte Carlo calculations and the model dependencies involved in the final result, assuming interaction models QGSJET01c and SIBYLL2.1, and heavy dominant (HD) and proton dominant (PD) primary composition models. Pure proton and pure iron primary models are also examined as extreme cases. A detector simulation was also performed to improve our accuracy in determining the size of the air showers and the energy of the primary particle. We confirmed that the all-particle energy spectra obtained under various plausible model parameters are not significantly different from each other, which was the expected result given the characteristics of the experiment at high altitude, where the air showers of the primary energy around the knee reach near-maximum development, with their features dominated by electromagnetic components, leading to a weak dependence on the interaction model or the primary mass. This is the highest statistical and the best systematics-controlled measurement covering the widest energy range around the knee energy region.

  6. Detecting atmospheric cosmic ray induced muon showers with the NO νA Far Detector

    NASA Astrophysics Data System (ADS)

    Sultana, Mehreen

    2015-04-01

    The research goals of Fermilab's NuMi Off-Axis Electron Neutrino Appearance (NO νA) are to observe muon neutrino to electron neutrino oscillations, determine the ordering of neutrino masses, and explain violation of matter/anti-matter symmetry. However, NO νA can also be used to study cosmic ray induced high energy extensive air showers. This poster describes the initial characterization of NO νA as a cosmic ray detector. The detector has a combination of large size and high spatial resolution that will allow future studies of the hadronic cores of cosmic ray air showers. A large component of these showers are muons. Multiple parallel muon tracks seen in a single event with the NO νA detectors result from the same primary cosmic ray collision in the upper atmosphere. In order to use these muon bundles to probe the cosmic ray physics involved, we determine event characteristics such as the multiplicity of observed multiple muons, the effective area of the detector, the angular resolution of the detector, the scattering of individual muons, and the effectiveness of identifying and isolating these parallel muon shower events from background and noise. NuMi Off-Axis Electron Neutrino Appearance Experiment.

  7. Interior view of bath 1 showing original tub and shower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of bath 1 showing original tub and shower stall, facing southwest. - Albrook Air Force Station, Field Officer's Quarters, West side of Dargue Avenue Circle, Balboa, Former Panama Canal Zone, CZ

  8. Detection of very inclined showers with the Auger Observatory

    SciTech Connect

    Nellen, Lukas; /Mexico U., ICN

    2005-07-01

    The Pierre Auger Observatory can detect air showers with high efficiency at large zenith angles with both the fluorescence and surface detectors. Since half the available solid angle corresponds to zeniths between 60 and 90 degrees, a large number of inclined events can be expected and are indeed observed. In this paper, we characterize the inclined air showers detected by the Observatory and we present the aperture for inclined showers and an outlook of the results that can be obtained in future studies of the inclined data set.

  9. Effect of Initial Mixture Temperature on Flame Speed of Methane-Air, Propane-Air, and Ethylene-Air Mixtures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L

    1952-01-01

    Flame speeds based on the outer edge of the shadow cast by the laminar Bunsen cone were determined as functions of composition for methane-air mixtures at initial mixture temperatures ranging from -132 degrees to 342 degrees c and for propane-air and ethylene-air mixtures at initial mixture temperatures ranging from -73 degrees to 344 degrees c. The data showed that maximum flame speed increased with temperature at an increasing rate. The percentage change in flame speed with change in initial temperature for the three fuels followed the decreasing order, methane, propane, and ethylene. Empirical equations were determined for maximum flame speed as a function of initial temperature over the temperature range covered for each fuel. The observed effect of temperature on flame speed for each of the fuels was reasonably well predicted by either the thermal theory as presented by Semenov or the square-root law of Tanford and Pease.

  10. SAMIRA - SAtellite based Monitoring Initiative for Regional Air quality

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Stebel, Kerstin; Ajtai, Nicolae; Diamandi, Andrei; Horalek, Jan; Nicolae, Doina; Stachlewska, Iwona; Zehner, Claus

    2016-04-01

    Here, we present a new ESA-funded project entitled Satellite based Monitoring Initiative for Regional Air quality (SAMIRA), which aims at improving regional and local air quality monitoring through synergetic use of data from present and upcoming satellites, traditionally used in situ air quality monitoring networks and output from chemical transport models. Through collaborative efforts in four countries, namely Romania, Poland, the Czech Republic and Norway, all with existing air quality problems, SAMIRA intends to support the involved institutions and associated users in their national monitoring and reporting mandates as well as to generate novel research in this area. Despite considerable improvements in the past decades, Europe is still far from achieving levels of air quality that do not pose unacceptable hazards to humans and the environment. Main concerns in Europe are exceedances of particulate matter (PM), ground-level ozone, benzo(a)pyrene (BaP) and nitrogen dioxide (NO2). While overall sulfur dioxide (SO2) emissions have decreased in recent years, regional concentrations can still be high in some areas. The objectives of SAMIRA are to improve algorithms for the retrieval of hourly aerosol optical depth (AOD) maps from SEVIRI, and to develop robust methods for deriving column- and near-surface PM maps for the study area by combining satellite AOD with information from regional models. The benefit to existing monitoring networks (in situ, models, satellite) by combining these datasets using data fusion methods will be tested for satellite-based NO2, SO2, and PM/AOD. Furthermore, SAMIRA will test and apply techniques for downscaling air quality-related EO products to a spatial resolution that is more in line with what is generally required for studying urban and regional scale air quality. This will be demonstrated for a set of study sites that include the capitals of the four countries and the highly polluted areas along the border of Poland and the

  11. Minor meteor shower activity

    NASA Astrophysics Data System (ADS)

    Rendtel, J.

    2016-01-01

    Video meteor observations provide us with data to analyze structures in minor meteor showers or weak features in flux profiles. Samples obtained independently by other techniques allow to calibrate the data sets and to improve the confidence of results as demonstrated with a few results. Both, the confirmation of events predicted by model calculation and the input of observational data to improve the modelling results may help to better understand meteoroid stream evolution processes. Furthermore, calibrated data series can be used for studies of the long-term evolution of meteor shower activity.

  12. X{sub max}{sup μ} vs. N{sup μ} from extensive air showers as estimator for the mass of primary UHECR's. Application for the Pierre Auger Observatory

    SciTech Connect

    Arsene, Nicusor; Sima, Octavian

    2015-02-24

    We study the possibility of primary mass estimation for Ultra High Energy Cosmic Rays (UHECR's) using the X{sub max}{sup μ} (the height where the number of muons produced on the core of Extensive Air Showers (EAS) is maximum) and the number N{sup μ} of muons detected on ground. We use the 2D distribution - X{sub max}{sup μ} against N{sup μ} in order to find its sensitivity to the mass of the primary particle. For that, we construct a 2D Probability Function Prob(p,Fe | X{sub max}{sup μ}, N{sup μ}) which estimates the probability that a certain point from the plane (X{sub max}{sup μ}, N{sup μ}) corresponds to a shower induced by a proton, respectively an iron nucleus. To test the procedure, we analyze a set of simulated EAS induced by protons and iron nuclei at energies of 10{sup 19}eV and 20° zenith angle with CORSIKA. Using the Bayesian approach and taking into account the geometry of the infill detectors from the Pierre Auger Observatory, we observe an improvement in the accuracy of the primary mass reconstruction in comparison with the results obtained using only the X{sub max}{sup μ} distributions.

  13. National Security Science and Technology Initiative: Air Cargo Screening

    SciTech Connect

    Bingham, Philip R; White, Tim; Cespedes, Ernesto; Bowerman, Biays; Bush, John

    2010-11-01

    The non-intrusive inspection (NII) of consolidated air cargo carried on commercial passenger aircraft continues to be a technically challenging, high-priority requirement of the Department of Homeland Security's Science and Technology Directorate (DHS S&T), the Transportation Security Agency and the Federal Aviation Administration. The goal of deploying a screening system that can reliably and cost-effectively detect explosive threats in consolidated cargo without adversely affecting the flow of commerce will require significant technical advances that will take years to develop. To address this critical National Security need, the Battelle Memorial Institute (Battelle), under a Cooperative Research and Development Agreement (CRADA) with four of its associated US Department of Energy (DOE) National Laboratories (Oak Ridge, Pacific Northwest, Idaho, and Brookhaven), conducted a research and development initiative focused on identifying, evaluating, and integrating technologies for screening consolidated air cargo for the presence of explosive threats. Battelle invested $8.5M of internal research and development funds during fiscal years 2007 through 2009. The primary results of this effort are described in this document and can be summarized as follows: (1) Completed a gap analysis that identified threat signatures and observables, candidate technologies for detection, their current state of development, and provided recommendations for improvements to meet air cargo screening requirements. (2) Defined a Commodity/Threat/Detection matrix that focuses modeling and experimental efforts, identifies technology gaps and game-changing opportunities, and provides a means of summarizing current and emerging capabilities. (3) Defined key properties (e.g., elemental composition, average density, effective atomic weight) for basic commodity and explosive benchmarks, developed virtual models of the physical distributions (pallets) of three commodity types and three explosive

  14. Chapter 4: Assessing the Air Pollution, Greenhouse Gas, Air Quality, and Health Benefits of Clean Energy Initiatives

    EPA Pesticide Factsheets

    Chapter 4 of “Assessing the Multiple Benefits of Clean Energy” helps state energy, environmental, and economic policy makers assess the air quality, greenhouse gas, air pollution, and health benefits of clean energy initiatives.

  15. Flame Speeds of Methane-Air, Propane-Air, and Ethylene-Air Mixtures at Low Initial Temperatures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L; Heimel, Sheldon

    1952-01-01

    Flame speeds were determined for methane-air, propane-air, and ethylene-air mixtures at -73 C and for methane-air mixtures at -132 C. The data extend the curves of maximum flame speed against initial mixture temperature previously established for the range from room temperature to 344 C. Empirical equations for maximum flame speed u(cm/ sec) as a function of initial mixture temperature T(sub O) were determined to be as follows: for methane, for T(sub O) from 141 to 615 K, u = 8 + 0.000160 T(sub O)(exp 2.11); for propane, for T(sub O) from 200 to 616 K, u = 10 + 0.000342 T(sub O)(exp 2.00); for ethylene, for T(sub O) from 200 to 617 K, u = 10 + 0.00259 T(sub O)(exp 1.74). Relative flame speeds at low initial temperatures were predicted within approximately 20 percent by either the thermal theory as presented by Semenov or by the diffusion theory of Tanford and Pease. The same order was found previously for high initial temperatures. The low-temperature data were also found to extend the linear correlations between maximum flame speed and calculated equilibrium active-radical concentrations, which were established by the previously reported high-temperature data.

  16. Portable shower apparatus

    NASA Technical Reports Server (NTRS)

    Grenier, Francis E. (Inventor)

    1993-01-01

    A multipurpose, collapsible, shower apparatus for use almost anywhere but especially adapted for use in places somewhat remote from civilization such as recreational vehicles, campers, the outdoors, space vehicles and the like where there may be a limited amount of water or other liquid. The collapsible shower apparatus includes a curtain assembly having an inner wall, an outer wall and a porous element for separating the inner and outer walls; a series of spaced hollow hoops connected by one or more sets of hollow tubes (manifolds); one or more nozzles connected to and in communication with at least one of the hollow hoops; a source of fluid under pressure in communication with at least one of the hollow hoops; and a suction pump for withdrawing fluid from the interior of the curtain assembly.

  17. Saving water in showers

    NASA Astrophysics Data System (ADS)

    Alkhaddar, R. A.; Phipps, D.; Morgan, R.; Karci, B.; Hordesseux, J.

    2007-07-01

    This project is part of a programme aimed at reducing water consumption. Power showers are water inefficient, but in order to persuade the user to accept a lower water use it will be necessary to sustain the "shower experience" to maintain user satisfaction. Previous work has indicated that users' requirements include temperature stability, adequate water volume and distribution, and skin pressure, all of which are substantially controlled by the showerhead. In the present phase of the project several commercially available domestic showerheads have been examined to determine pressure-volume characteristics, radial spray distributions at different flow rates, direct and indirect measures of "skin pressure" and measurements of vertical temperature profiles. Part of the practical work at LJMU has supported extensive theoretical studies by CFD carried out by staff at Arup (consulting engineers) for the Market Transformation Programme. A future phase will study user satisfaction in their own homes where user satisfaction will be surveyed and linked to the physical performance of the shower.

  18. Separation and confirmation of showers

    NASA Astrophysics Data System (ADS)

    Neslušan, L.; Hajduková, M.

    2017-01-01

    Aims: Using IAU MDC photographic, IAU MDC CAMS video, SonotaCo video, and EDMOND video databases, we aim to separate all provable annual meteor showers from each of these databases. We intend to reveal the problems inherent in this procedure and answer the question whether the databases are complete and the methods of separation used are reliable. We aim to evaluate the statistical significance of each separated shower. In this respect, we intend to give a list of reliably separated showers rather than a list of the maximum possible number of showers. Methods: To separate the showers, we simultaneously used two methods. The use of two methods enables us to compare their results, and this can indicate the reliability of the methods. To evaluate the statistical significance, we suggest a new method based on the ideas of the break-point method. Results: We give a compilation of the showers from all four databases using both methods. Using the first (second) method, we separated 107 (133) showers, which are in at least one of the databases used. These relatively low numbers are a consequence of discarding any candidate shower with a poor statistical significance. Most of the separated showers were identified as meteor showers from the IAU MDC list of all showers. Many of them were identified as several of the showers in the list. This proves that many showers have been named multiple times with different names. Conclusions: At present, a prevailing share of existing annual showers can be found in the data and confirmed when we use a combination of results from large databases. However, to gain a complete list of showers, we need more-complete meteor databases than the most extensive databases currently are. We also still need a more sophisticated method to separate showers and evaluate their statistical significance. Tables A.1 and A.2 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  19. Assessing human exposure and odor detection during showering with crude 4-(methylcyclohexyl)methanol (MCHM) contaminated drinking water.

    PubMed

    Sain, Amanda E; Dietrich, Andrea M; Smiley, Elizabeth; Gallagher, Daniel L

    2015-12-15

    In 2014, crude (4-methylcyclohexyl)methanol (MCHM) spilled, contaminating the drinking water of 300,000 West Virginians and requiring "do not use" orders to protect human health. When the spill occurred, known crude MCHM physicochemical properties were insufficient to predict human inhalation and ingestion exposures. Objectives are (1) determine Henry's Law Constants (HLCs) for 4-MCHM isomers at 7, 25, 40, and 80°C using gas chromatography; (2) predict air concentrations of 4-MCHM and methyl-4-methylcyclohexanecarboxylate (MMCHC) during showering using an established shower model; (3) estimate human ingestion and inhalation exposure to 4-MCHM and MMCHC; and (4) determine if predicted air 4-MCHM exceeded odor threshold concentrations. Dimensionless HLCs of crude cis- and trans-4-MCHM were measured to be 1.42×10(-4)±6% and 3.08×10(-4)±3% at 25°C, respectively, and increase exponentially with temperature as predicted by the van't Hoff equation. Shower air concentrations for cis- and trans-4-MCHM are predicted to be 0.089 and 0.390ppm-v respectively after 10min, exceeding the US EPA's 0.01ppm-v air screening level during initial spill conditions. Human exposure doses were predicted using measured drinking water and predicted shower air concentrations and found to greatly exceed available guidance levels in the days directly following the spill. Odors would be rapidly detected by 50% of individuals at aqueous concentrations below analytical gas chromatographic detection limits. MMCHC, a minor odorous component (0.935%) of crude MCHM, is also highly volatile and therefore is predicted to contribute to inhalation exposures and odors experienced by consumers.

  20. An in-premise model for Legionella exposure during showering events

    EPA Science Inventory

    An exposure model was constructed to predict the critical Legionella densities in an engineered water system that might result in infection from inhalation of aerosols containing the pathogen while showering. The model predicted the Legionella densities in the shower air, water ...

  1. A new approach to estimating the volatilization rates of shower water-contained volatile organic compounds during showering

    NASA Astrophysics Data System (ADS)

    Chen, M. J.; Wu, K. Y.; Chang, L.

    A mathematical hybrid-showering model was developed in order to describe the dynamic behaviour of volatile organic compounds (VOCs) contained in shower water during personal showering. The approach involves assuming a two-film theory and taking into account the dual flow patterns of "jet" and "spray" from a showerhead in order to estimate the emission of VOCs from tap water to air. The liquid-phase mass-transfer coefficients corresponding to both flow patterns and the gas-phase mass-transfer coefficient for spray droplets are estimated using the penetration theory, while the gas-phase mass-transfer coefficient for a jet-flow stream is calculated using an analogous empirical correlation. Literature-derived data were used to test the validity of the hybrid-showering model and a good correlation between literature-derived and calculated data was obtained. This study confirms the usefulness of the hybrid-showering modelling approach as regards the risk assessment of personal showering. Moreover, our simulated findings indicated that the jet-flow type showerhead should be more beneficial than the spray type showerhead as regards being associated with a lower VOC exposure risk.

  2. Future of Monte Carlo simulations of atmospheric showers

    NASA Astrophysics Data System (ADS)

    Pierog, Tanguy; Engel, Ralph; Heck, Dieter; Poghosyan, Gevorg

    2015-03-01

    In 2013, the air shower simulation model CORSIKA had a major release opening new windows in term of uncertainty due to hadronic interaction models and of simulation time. On the one hand, the two hadronic models EPOS and QGSJETII were updated taking into account new LHC data. As a consequence the uncertainties in air shower observables were reduced by about a factor of 2 at the highest energies. On the second hand, two new possibilites of running CORSIKA were introduced: either in a parallel mode on big CPU clusters allowing the simulation of unthinned showers in a reasonable time, or using cascade equations to reduce the simulation time by about of factor of 10 on a single CPU. All these improvements will be presented.

  3. Space-Time Analysis of the Air Quality Model Evaluation International Initiative (AQMEII) Phase 1 Air Quality Simulations

    EPA Science Inventory

    This study presents an evaluation of summertime daily maximum ozone concentrations over North America (NA) and Europe (EU) using the database generated during Phase 1 of the Air Quality Model Evaluation International Initiative (AQMEII). The analysis focuses on identifying tempor...

  4. Central Texas Group Among Clean Air and Climate Initiatives to Win EPA Honors

    EPA Pesticide Factsheets

    DALLAS - (April 21, 2015) This week, the U.S. Environmental Protection Agency (EPA) has honored the CLEAN AIR Force of Central Texas for their work on clean air and climate initiatives. The 2015 Clean Air Excellence Award recognizes innovative state

  5. Interim Report for Bioventing Field Initiative at Robins Air Force Base, Georgia

    DTIC Science & Technology

    2007-11-02

    This report describes the activities conducted at Robins Air Force Base (AFB), Georgia, as part of the Bioventing Field Initiative for the U.S. Air...soil gas survey, air permeability test, in situ respiration tests, and installation of bioventing systems. The specific objectives of this task are described in the following section.

  6. Detection of tau neutrinos by imaging air Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Góra, D.; Bernardini, E.

    2016-09-01

    This paper investigates the potential to detect tau neutrinos in the energy range of 1-1000 PeV searching for very inclined showers with imaging Cherenkov telescopes. A neutrino induced tau lepton escaping from the Earth may decay and initiate an air shower which can be detected by a fluorescence or Cherenkov telescope. We present here a study of the detection potential of Earth-skimming neutrinos taking into account neutrino interactions in the Earth crust, local matter distributions at various detector sites, the development of tau-induced showers in air and the detection of Cherenkov photons with IACTs. We analyzed simulated shower images on the camera focal plane and implemented generic reconstruction chains based on Hillas parameters. We find that present IACTs can distinguish air showers induced by tau neutrinos from the background of hadronic showers in the PeV-EeV energy range. We present the neutrino trigger efficiency obtained for a few configurations being considered for the next-generation Cherenkov telescopes, i.e. the Cherenkov Telescope Array. Finally, for a few representative neutrino spectra expected from astrophysical sources, we compare the expected event rates at running IACTs to what is expected for the dedicated IceCube neutrino telescope.

  7. Pursuing a historical meteor shower

    NASA Astrophysics Data System (ADS)

    Watanabe, Jun-Ichi; Sato, Mikiya; Kasuga, Toshihiro

    2006-11-01

    The strong outburst of the Phoenicids was witnessed by people in a Japanese expedition ship, Soya, in 1956. After that, this meteor shower has never been observed at this activity level. Although its parent comet has not been strictly identified, the possible candidate was the comet D/1819W1 (Blanpain) which appeared only once in 1819. A newly discovered asteroid 2003WY25 becomes a clue to the mystery of this meteor shower. We introduce our result on the investigation of this meteor shower on the basis of the dust trail theory.

  8. Bioventing Field Initiative at Galena and Campion Air Force Stations, Alaska

    DTIC Science & Technology

    2007-11-02

    This report describes the activities conducted at Galena Air Force Station (AFS) and Campion AFS, Alaska, as part of the Bioventing Field Initiative...air permeability test, in situ respiration tests, and installation of bioventing systems. The specific objectives of this Bioventing Field Initiative

  9. Various meteor scenes III: Recurrent showers and some minor showers

    NASA Astrophysics Data System (ADS)

    Koseki, Masahiro

    2015-02-01

    Meteor activities vary widely from year to year. We study here the June Bootids (JBO), τ-Herculids (TAH), and Andromedids (AND) which are basic examples for the recurrent nature of meteor showers. Half a century has passed since well-known photographic or radar meteor showers were detected. It is necessary to note that some `established' IAU showers are historical ones and we cannot always see them. We find the historical trace of AND by video and four distinct activities in the area of JBC (=JBO+TAH). Meteor showers look different by different observational techniques. Many minor showers in the IAU list have been detected only by observations stored for many days and many years; visual observations in a single night cannot perceive them naturally. We studied the φ-Piscids (PPS), χ-Taurids (CTA), γ-Ursae Minorids (GUM), η-Pegasids (ETP), and α-Sextantids (ASX) as examples and found they have not been recognized by visual observers at all. It is noteworthy that some of them have possible identifications in the IAU list and in preceding observations or reports. The difference in search methods makes the situations much more complicated. The five minor showers we studied here do not have confirmations by all observational techniques. Geobased search (radiant point, time of the observation, and possibly geocentric velocity) may overlook showers which are dispersed in radiant position. A search using the D-criterion is dependent on the presumption of a spherical distribution in the orbital space and may not represent the real distribution, or may overestimate the accuracy of the observations and lead to subdividing the showers into several parts. We must use these search methods properly.

  10. Mexico City Air Quality Research Initiative; Volume 5, Strategic evaluation

    SciTech Connect

    1994-03-01

    Members of the Task HI (Strategic Evaluation) team were responsible for the development of a methodology to evaluate policies designed to alleviate air pollution in Mexico City. This methodology utilizes information from various reports that examined ways to reduce pollutant emissions, results from models that calculate the improvement in air quality due to a reduction in pollutant emissions, and the opinions of experts as to the requirements and trade-offs that are involved in developing a program to address the air pollution problem in Mexico City. The methodology combines these data to produce comparisons between different approaches to improving Mexico City`s air quality. These comparisons take into account not only objective factors such as the air quality improvement or cost of the different approaches, but also subjective factors such as public acceptance or political attractiveness of the different approaches. The end result of the process is a ranking of the different approaches and, more importantly, the process provides insights into the implications of implementing a particular approach or policy.

  11. Electromagnetic Showers at High Energy

    ERIC Educational Resources Information Center

    Loos, J. S.; Dawson, S. L.

    1978-01-01

    Some of the properties of electromagnetic showers observed in an experimental study are illustrated. Experimental data and results from quantum electrodynamics are discussed. Data and theory are compared using computer simulation. (BB)

  12. Air Force Research Initiation Program. 1986 Technical Report. Volume 3

    DTIC Science & Technology

    1988-04-01

    at Orono Jackson State University Specialty: Mathematical Statistics Specialty: Educational Psychology WILFORD HALL MEDICAL CENTER (Lackland Air Force...had a considerable 71-5 practical experience in applied research , administration, teaching and pedagogy, athletics and coaching, psychology , and...of facts and the frontier method preferred for procedural skills that have prerequisite relations. Second , once a topic, or more particularly a

  13. Initial Air Traffic Control Training at Tartu Aviation College.

    ERIC Educational Resources Information Center

    Kulbas, Tanel

    1997-01-01

    Development of an air traffic control (ATC) training course at Tartu Aviation College in Estonia had to start at ground zero, creating new rules and regulations for ATC, writing special study materials, building simulators, and finding enough applicants with sufficient English skills. (SK)

  14. Laser Initiation and Radiofrequency Sustainment of Seeded Air Plasmas

    DTIC Science & Technology

    2006-04-01

    pressure plasma that projects well away from the antenna by this means that could not be obtained by RF alone. The initial plasma ionization also...a much lower RF power levels and with more enhanced axial projection away from the antenna with laser initiation than without. Power densities of 1...SCIENTECH ( Astral AD30). In order to account for the laser attenuation by the UV window, the UV window is placed in front of the energy meter. A laser

  15. Air-To-Air Combat Skills: Contribution of Platform Motion to Initial Training

    DTIC Science & Technology

    1978-10-01

    AFHRL/FT) using the Advanced Simulator for Air-to-Air Combat (SAAC); (b) an A/A study Pilot Training ( ASPT ) indicated that platform using Northrop...Advanced interested in the implication of these findings in Simulator for Pilot Training ( ASPT ) at Williams view of their planned simulator procurements...i.e., air-to-surface weapons delivery TAC’s request, but the ASPT A/S study was (A/S) and air-to-air combat (A/A), was questioned. completed (Gray

  16. Test results on re-use of reclaimed shower water: Summary. [space stations

    NASA Technical Reports Server (NTRS)

    Verostko, C. E.; Garcia, R.; Sauer, R.; Linton, A. T.; Elms, T.; Reysa, R. P.

    1988-01-01

    A microgravity whole body shower (WBS) and waste water recovery systems (WWRS) were evaluated in three separate closed loop tests. Following a protocol similar to that anticipated for the U.S. Space Station, test subjects showered in a prototype whole body shower. The WWRS processes evaluated during the test series were phase change and reverse osmosis (RO). A preprototype Thermoelectric Integrated Hollow Fiber Membrane Evaporation Subsystem phase change process was used for the initial test with chemical pretreatment of the shower water waste input. The second and third tests concentrated on RO technologies. The second test evaluated a dynamic RO membrane consisting of zirconium oxide polyacrylic acid (ZOPA) membranes deposited on the interior diameter of 316L porous stainless steel tubes while the final test employed a thin semipermeable RO membrane deposited on the interior surface of polysulfone hollow fibers. All reclaimed water was post-treated for purity using ion exchange and granular activated carbon beds immediately followed by microbial control treatment using both heat and iodine. The test hardware, controls exercised for whole body showering, types of soaps evaluated, shower subject response to reclaimed water showering, and shower water collection and chemical pretreatment (if required) for microbial control are described. The WWRS recovered water performance and the effectiveness of the reclaimed water post-treatment techniques used for maintaining water purity and microorganism control are compared. Results on chemical and microbial impurity content of the water samples obtained from various locations in the shower water reuse system are summarized.

  17. Participatory Patterns in an International Air Quality Monitoring Initiative

    PubMed Central

    Sîrbu, Alina; Becker, Martin; Caminiti, Saverio; De Baets, Bernard; Elen, Bart; Francis, Louise; Gravino, Pietro; Hotho, Andreas; Ingarra, Stefano; Loreto, Vittorio; Molino, Andrea; Mueller, Juergen; Peters, Jan; Ricchiuti, Ferdinando; Saracino, Fabio; Servedio, Vito D. P.; Stumme, Gerd; Theunis, Jan; Tria, Francesca; Van den Bossche, Joris

    2015-01-01

    The issue of sustainability is at the top of the political and societal agenda, being considered of extreme importance and urgency. Human individual action impacts the environment both locally (e.g., local air/water quality, noise disturbance) and globally (e.g., climate change, resource use). Urban environments represent a crucial example, with an increasing realization that the most effective way of producing a change is involving the citizens themselves in monitoring campaigns (a citizen science bottom-up approach). This is possible by developing novel technologies and IT infrastructures enabling large citizen participation. Here, in the wider framework of one of the first such projects, we show results from an international competition where citizens were involved in mobile air pollution monitoring using low cost sensing devices, combined with a web-based game to monitor perceived levels of pollution. Measures of shift in perceptions over the course of the campaign are provided, together with insights into participatory patterns emerging from this study. Interesting effects related to inertia and to direct involvement in measurement activities rather than indirect information exposure are also highlighted, indicating that direct involvement can enhance learning and environmental awareness. In the future, this could result in better adoption of policies towards decreasing pollution. PMID:26313263

  18. Participatory Patterns in an International Air Quality Monitoring Initiative.

    PubMed

    Sîrbu, Alina; Becker, Martin; Caminiti, Saverio; De Baets, Bernard; Elen, Bart; Francis, Louise; Gravino, Pietro; Hotho, Andreas; Ingarra, Stefano; Loreto, Vittorio; Molino, Andrea; Mueller, Juergen; Peters, Jan; Ricchiuti, Ferdinando; Saracino, Fabio; Servedio, Vito D P; Stumme, Gerd; Theunis, Jan; Tria, Francesca; Van den Bossche, Joris

    2015-01-01

    The issue of sustainability is at the top of the political and societal agenda, being considered of extreme importance and urgency. Human individual action impacts the environment both locally (e.g., local air/water quality, noise disturbance) and globally (e.g., climate change, resource use). Urban environments represent a crucial example, with an increasing realization that the most effective way of producing a change is involving the citizens themselves in monitoring campaigns (a citizen science bottom-up approach). This is possible by developing novel technologies and IT infrastructures enabling large citizen participation. Here, in the wider framework of one of the first such projects, we show results from an international competition where citizens were involved in mobile air pollution monitoring using low cost sensing devices, combined with a web-based game to monitor perceived levels of pollution. Measures of shift in perceptions over the course of the campaign are provided, together with insights into participatory patterns emerging from this study. Interesting effects related to inertia and to direct involvement in measurement activities rather than indirect information exposure are also highlighted, indicating that direct involvement can enhance learning and environmental awareness. In the future, this could result in better adoption of policies towards decreasing pollution.

  19. New air Cherenkov light detectors to study mass composition of cosmic rays with energies above knee region

    NASA Astrophysics Data System (ADS)

    Tsunesada, Yoshiki; Katsuya, Ryoichi; Mitsumori, Yu; Nakayama, Keisuke; Kakimoto, Fumio; Tokuno, Hisao; Tajima, Norio; Miranda, Pedro; Salinas, Juan; Tavera, Wilfredo

    2014-11-01

    We have installed a hybrid detection system for air showers generated by cosmic rays with energies greater than 3 ×1015 eV at Mount Chacaltaya (5200 m above the sea level), in order to study the mass composition of cosmic rays above the knee region. This detection system comprises an air shower array with 49 scintillation counters in an area of 500 m×650 m, and seven new Cherenkov light detectors installed in a radial direction from the center of the air shower array with a separation of 50 m. It is known that the longitudinal development of a particle cascade in the atmosphere strongly depends on the type of the primary nucleus, and an air shower initiated by a heavier nucleus develops faster than that by a lighter primary of the same energy, because of the differences in the interaction cross-section and the energy per nucleon. This can be measured by detecting the Cherenkov radiation emitted from charged particles in air showers at higher altitudes. In this paper we describe the design and performance of our new non-imaging Cherenkov light detectors at Mount Chacaltaya that are operated in conjunction with the air shower array. The arrival directions and energies of air showers are determined by the shower array, and information about the primary masses is obtained from the Cherenkov light data including the time profiles and lateral distributions. The detector consists of photomultiplier tube (PMT), high-speed ADCs, other control modules, and data storage device. The Cherenkov light signals from an air shower are typically 10-100 ns long, and the waveforms are digitized with a sampling frequency of 1 GHz and recorded in situ without long-distance analog signal transfers. All the Cherenkov light detectors record their time-series data by receiving a triggering signal transmitted from the trigger module of the air shower array, which is fired by a coincidence of shower signals in four neighboring scintillation counters. The optical characteristics of the

  20. Initiative in Soviet Air Force Tactics and Decision Making.

    DTIC Science & Technology

    1986-06-01

    control system has impacted the command style of pilots and low level commanders in different ways depending upon the military doctrine at the time...and control lost. How will low level commanders function if they can no longer receive orders from the high command? From a command and control...aircraft in a tighter turn than one’s opponent; superior tactics and the ability of pilots to act and think on their own initiative has made the difference

  1. Air Quality Model Evaluation International Initiative (AQMEII) - Utrecht, Netherlands The May 8, 2012

    EPA Science Inventory

    The 4th workshop of the Air Quality Model Evaluation International Initiative (AQMEII) was held on May 8 in Utrecht, The Netherlands, in conjunction with the NATO/SPS International Technical Meeting on Air Pollution Modeling and Its Application. AQMEII was launched in 2009 as a l...

  2. Path Forward for the Air Quality Model Evaluation International Initiative (AQMEII)

    EPA Science Inventory

    This article lays out the objectives for Phase 2 of the Air Quality Model Evaluation International Initiative (AQMEII). The inhalation of air pollutants such as ozone and fine particles has been linked to adverse impacts on human health, and the atmospheric deposition of pollutan...

  3. Interim Report for Bioventing Field Initiative at Site UST 173, Robins Air Force Base, Georgia

    DTIC Science & Technology

    2007-11-02

    This report describes the activities conducted at Robins Air Force Base (AFB), Georgia, Site UST 173 as part of the Bioventing Field Initiative for...which includes a soil gas survey, air permeability test, in situ respiration tests, and installation of bioventing systems. The specific objectives of this task are described in the following section.

  4. 40 CFR 60.2141 - By what date must I conduct the initial air pollution control device inspection?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air pollution control device inspection? 60.2141 Section 60.2141 Protection of Environment... initial air pollution control device inspection? (a) The initial air pollution control device inspection... startup. (b) Within 10 operating days following an air pollution control device inspection, all...

  5. 40 CFR 60.2141 - By what date must I conduct the initial air pollution control device inspection?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air pollution control device inspection? 60.2141 Section 60.2141 Protection of Environment... initial air pollution control device inspection? (a) The initial air pollution control device inspection... startup. (b) Within 10 operating days following an air pollution control device inspection, all...

  6. 1997 Leonid Shower from Space

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter; Nugent, David; Tedesco, Ed; Murthy, Jayant

    In November 1997, the Midcourse Space Experiment satellite (MSX) was deployed to observe the Leonid shower from space. The shower lived up to expectations, with abundant bright fireballs. Twenty-nine meteors were detected by a wide-angle, visible wavelength, camera near the limb of the Earth in a 48-minute interval, and three meteors by the narrow field camera. This amounts to a meteoroid influx of 5.5 +/- 0.6 10^-5 km^-2 hr^-1 for masses > 0.3 gram. The limiting magnitude for limb observations of Leonid meteors was measured at M_v = -1.5 magn. The Leonid shower magnitude population index was 1.6 +/- 0.2 down to M_v = -7 magn., with no sign of an upper mass cut-off.

  7. TIERRAS: A package to simulate high energy cosmic ray showers underground, underwater and under-ice

    NASA Astrophysics Data System (ADS)

    Tueros, Matías; Sciutto, Sergio

    2010-02-01

    In this paper we present TIERRAS, a Monte Carlo simulation program based on the well-known AIRES air shower simulations system that enables the propagation of particle cascades underground, providing a tool to study particles arriving underground from a primary cosmic ray on the atmosphere or to initiate cascades directly underground and propagate them, exiting into the atmosphere if necessary. We show several cross-checks of its results against CORSIKA, FLUKA, GEANT and ZHS simulations and we make some considerations regarding its possible use and limitations. The first results of full underground shower simulations are presented, as an example of the package capabilities. Program summaryProgram title: TIERRAS for AIRES Catalogue identifier: AEFO_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFO_v1_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.: 36 489 No. of bytes in distributed program, including test data, etc.: 3 261 669 Distribution format: tar.gz Programming language: Fortran 77 and C Computer: PC, Alpha, IBM, HP, Silicon Graphics and Sun workstations Operating system: Linux, DEC Unix, AIX, SunOS, Unix System V RAM: 22 Mb bytes Classification: 1.1 External routines: TIERRAS requires AIRES 2.8.4 to be installed on the system. AIRES 2.8.4 can be downloaded from http://www.fisica.unlp.edu.ar/auger/aires/eg_AiresDownload.html. Nature of problem: Simulation of high and ultra high energy underground particle showers. Solution method: Modification of the AIRES 2.8.4 code to accommodate underground conditions. Restrictions: In AIRES some processes that are not statistically significant on the atmosphere are not simulated. In particular, it does not include muon photonuclear processes. This imposes a limitation on the application of this package to a depth of

  8. Human respiratory uptake of chloroform and haloketones during showering.

    PubMed

    Xu, Xu; Weisel, Clifford P

    2005-01-01

    Inhalation is an important exposure route for volatile water contaminants, including disinfection by-products (DBPs). A controlled human study was conducted on six subjects to determine the respiratory uptake of haloketones (HKs) and chloroform, a reference compound, during showering. Breath and air concentrations of the DBPs were measured using gas chromatography and electron capture detector during and following the inhalation exposures. A lower percentage of the HKs (10%) is released from shower water to air than that of chloroform (56%) under the experiment conditions due to the lower volatility of the HKs. Breath concentrations of the DBPs were elevated during the inhalation exposure, while breath concentrations decreased rapidly after the exposure. Approximately 85-90% of the inhaled HKs were absorbed, whereas only 70% of the inhaled chloroform was absorbed for the experiment conditions used. The respiratory uptake of the DBPs was estimated using a linear one-compartment model coupled with a plug flow stream model for the shower system. The internal dose of chloroform normalized to its water concentration was approximately four times that of the HKs after a 30-min inhalation exposure. Approximately 0.3-0.4% of the absorbed HKs and 2-9% of the absorbed chloroform were expired through lung excretion after the 30-min exposure. The inhalation exposure from a typical 10-15 min shower contributes significantly to the total dose for chloroform in chlorinated drinking water but only to a moderate extent for HKs.

  9. Interim Report for Bioventing Field Initiative at Westover Air Force Base, Massachusetts

    DTIC Science & Technology

    2007-11-02

    This report describes the activities conducted at Westover Air Force Base (AFB), Massachusetts, as part of the Bioventing Field Initiative for the...respiration test, and installation of bioventing systems. The specific objectives of this Bioventing Field Initiative are described in the following section

  10. Parton shower Monte Carlo event generators

    NASA Astrophysics Data System (ADS)

    Webber, Bryan

    2011-12-01

    A parton shower Monte Carlo event generator is a computer program designed to simulate the final states of high-energy collisions in full detail down to the level of individual stable particles. The aim is to generate a large number of simulated collision events, each consisting of a list of final-state particles and their momenta, such that the probability to produce an event with a given list is proportional (approximately) to the probability that the corresponding actual event is produced in the real world. The Monte Carlo method makes use of pseudorandom numbers to simulate the event-to-event fluctuations intrinsic to quantum processes. The simulation normally begins with a hard subprocess, shown as a black blob in Figure 1, in which constituents of the colliding particles interact at a high momentum scale to produce a few outgoing fundamental objects: Standard Model quarks, leptons and/or gauge or Higgs bosons, or hypothetical particles of some new theory. The partons (quarks and gluons) involved, as well as any new particles with colour, radiate virtual gluons, which can themselves emit further gluons or produce quark-antiquark pairs, leading to the formation of parton showers (brown). During parton showering the interaction scale falls and the strong interaction coupling rises, eventually triggering the process of hadronization (yellow), in which the partons are bound into colourless hadrons. On the same scale, the initial-state partons in hadronic collisions are confined in the incoming hadrons. In hadron-hadron collisions, the other constituent partons of the incoming hadrons undergo multiple interactions which produce the underlying event (green). Many of the produced hadrons are unstable, so the final stage of event generation is the simulation of the hadron decays.

  11. Hybrid shower counter for CDF

    SciTech Connect

    Nodulman, L.

    1980-01-01

    A hybrid scintillator/strip chamber electromagnetic calorimeter has been proposed for the Collider Detector Facility at Fermilab. Large modules of lead/scintillator with wavebar readout are to contain one or more bidimensional wire chambers near shower maximum. Results of the ongoing program of computer simulation and prototype testing are discussed.

  12. Results on reuse of reclaimed shower water

    NASA Technical Reports Server (NTRS)

    Verostko, Charles E.; Garcia, Rafael; Pierson, Duane L.; Reysa, Richard P.; Irbe, Robert

    1986-01-01

    The Waste Water Recovery System that has been used in conjunction with a microgravity whole body shower to test a closed loop shower water reclamation system applicable to the NASA Space Station employs a Thermoelectric Integrated Hollow Fiber Membrane Evaporation Subsystem. Attention is given to the suitability of a Space Shuttle soap for such crew showers, the effects of shower water on the entire system, and the purification qualities of the recovered water. The chemical pretreatment of the shower water for microorganism control involved activated carbon, mixed ion exchange resin beds, and iodine bactericide dispensing units. The water was recycled five times, demonstrating the feasibility of reuse.

  13. CAMS confirmation of previously reported meteor showers

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.; Nénon, Q.; Gural, P. S.; Albers, J.; Haberman, B.; Johnson, B.; Holman, D.; Morales, R.; Grigsby, B. J.; Samuels, D.; Johannink, C.

    2016-03-01

    Leading up to the 2015 IAU General Assembly, the International Astronomical Union's Working List of Meteor Showers included 486 unconfirmed showers, showers that are not certain to exist. If confirmed, each shower would provide a record of past comet or asteroid activity. Now, we report that 41 of these are detected in the Cameras for Allsky Meteor Surveillance (CAMS) video-based meteor shower survey. They manifest as meteoroids arriving at Earth from a similar direction and orbit, after removing the daily radiant drift due to Earth's motion around the Sun. These showers do exist and, therefore, can be moved to the IAU List of Established Meteor Showers. This adds to 31 previously confirmed showers from CAMS data. For each shower, finding charts are presented based on 230,000 meteors observed up to March of 2015, calculated by re-projecting the drift-corrected Sun-centered ecliptic coordinates into more familiar equatorial coordinates. Showers that are not detected, but should have, and duplicate showers that project to the same Sun-centered ecliptic coordinates, are recommended for removal from the Working List.

  14. 40 CFR 60.2706 - By what date must I conduct the initial air pollution control device inspection?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air pollution control device inspection? 60.2706 Section 60.2706 Protection of Environment... Requirements § 60.2706 By what date must I conduct the initial air pollution control device inspection? (a) The initial air pollution control device inspection must be conducted within 60 days after installation of...

  15. 40 CFR 60.2141 - By what date must I conduct the initial air pollution control device inspection?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air pollution control device inspection? 60.2141 Section 60.2141 Protection of Environment... Compliance Requirements § 60.2141 By what date must I conduct the initial air pollution control device inspection? (a) The initial air pollution control device inspection must be conducted within 60 days...

  16. 40 CFR 60.2141 - By what date must I conduct the initial air pollution control device inspection?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air pollution control device inspection? 60.2141 Section 60.2141 Protection of Environment... Compliance Requirements § 60.2141 By what date must I conduct the initial air pollution control device inspection? (a) The initial air pollution control device inspection must be conducted within 60 days...

  17. Development of cosmic ray simulation program: Earth cosmic ray shower (ECRS)

    NASA Astrophysics Data System (ADS)

    Hakmana Witharana, Sampath

    ECRS is a program for the detailed simulation of extensive air shower initiated by high energy cosmic ray particles. In this dissertation work, a Geant4 based ECRS simulation was designed and developed to study secondary cosmic ray particle showers in the full range of Earth's atmosphere. A proper atmospheric air density and geomagnetic field are implemented in order to correctly simulate the charged particles interactions in the Earth's atmosphere. The initial simulation was done for the Atlanta (33.46° N , 84.25° W) region. Four different types of primary proton energies (10^9 , 10^10 , 10^11 and 10 12 eV) were considered to determine the secondary particle distribution at the Earth's surface. The geomagnetic field and atmospheric air density have considerable effects on the muon particle distribution at the Earth's surface. The muon charge ratio at the Earth's surface was studied with ECRS simulation for two different geomagnetic locations: Atlanta, Georgia, USA and Lynn Lake, Manitoba, Canada. The simulation results are shown in excellent agreement with the data from NMSU-WIZARD/CAPRICE and BESS experiments at Lynn Lake. At low momentum, ground level muon charge ratios show latitude dependent geomagnetic effects for both Atlanta and Lynn Lake from the simulation. The simulated charge ratio is 1.20 ± 0.05 (without geomagnetic field), 1.12 ± 0.05 (with geomagnetic field) for Atlanta and 1.22 ± 0.04 (with geomagnetic field) for Lynn Lake. These types of studies are very important for analyzing secondary cosmic ray muon flux distribution at the Earth's surface and can be used to study the atmospheric neutrino oscillations.

  18. Sensitivity of the correlation between the depth of shower maximum and the muon shower size to the cosmic ray composition

    NASA Astrophysics Data System (ADS)

    Younk, Patrick; Risse, Markus

    2012-07-01

    The composition of ultra-high energy cosmic rays is an important issue in astroparticle physics research, and additional experimental results are required for further progress. Here we investigate what can be learned from the statistical correlation factor r between the depth of shower maximum and the muon shower size, when these observables are measured simultaneously for a set of air showers. The correlation factor r contains the lowest-order moment of a two-dimensional distribution taking both observables into account, and it is independent of systematic uncertainties of the absolute scales of the two observables. We find that, assuming realistic measurement uncertainties, the value of r can provide a measure of the spread of masses in the primary beam. Particularly, one can differentiate between a well-mixed composition (i.e., a beam that contains large fractions of both light and heavy primaries) and a relatively pure composition (i.e., a beam that contains species all of a similar mass). The number of events required for a statistically significant differentiation is ˜200. This differentiation, though diluted, is maintained to a significant extent in the presence of uncertainties in the phenomenology of high energy hadronic interactions. Testing whether the beam is pure or well-mixed is well motivated by recent measurements of the depth of shower maximum.

  19. Monte Carlo Shower Counter Studies

    NASA Technical Reports Server (NTRS)

    Snyder, H. David

    1991-01-01

    Activities and accomplishments related to the Monte Carlo shower counter studies are summarized. A tape of the VMS version of the GEANT software was obtained and installed on the central computer at Gallaudet University. Due to difficulties encountered in updating this VMS version, a decision was made to switch to the UNIX version of the package. This version was installed and used to generate the set of data files currently accessed by various analysis programs. The GEANT software was used to write files of data for positron and proton showers. Showers were simulated for a detector consisting of 50 alternating layers of lead and scintillator. Each file consisted of 1000 events at each of the following energies: 0.1, 0.5, 2.0, 10, 44, and 200 GeV. Data analysis activities related to clustering, chi square, and likelihood analyses are summarized. Source code for the GEANT user subprograms and data analysis programs are provided along with example data plots.

  20. Study of the shower maximum depth by the method of detection of the EAS Cerenkov light pulse shape

    NASA Technical Reports Server (NTRS)

    Aliev, N.; Alimov, T.; Kakhkharov, M.; Khakimov, N.; Makhmudov, B. M.; Rakhimova, N.; Tashpulatov, R.; Khristiansen, G. B.; Prosin, V. V.; Zhukov, V. Y.

    1985-01-01

    The results of processing the data on the shape of the EAS Cerenkov light pulses recorded by the extensive air showers (EAS) array are presented. The pulse FWHM is used to find the mean depth of EAS maximum.

  1. Final Environmental Assessment Nellis Air Force Base School Initiative, Nellis Air Force Base, Clark County, Nevada

    DTIC Science & Technology

    2015-04-01

    communication, electrical, gas, water, and sewer lines. No asbestos -containing or lead-containing materials would be used In construction of the new school...AFB School Initiative EA ix Final ACRONYMS AND ABBREVIATIONS ACHP Advisory Council on Historic Preservation ACM asbestos -containing materials ACS...approximately 3- to 10-acre site. The new school would be connected to existing communication, electrical, gas, water, and sewer lines. No asbestos

  2. Initial Validation of an Ambient Air Quality Model for Naval Air Operations.

    DTIC Science & Technology

    1980-12-01

    INITIAL LINE SOURCE DIMEN’SIONS AND DISPERSION PARAMETERS ------------------------------------- 37 . CONCLUSIONS- -------------------------- 39 iii V...types is further reduced by geometric configura- ticn to either a point, line or area source. Data are input to the Source Inventory program relative...source dimensions and meteorological stability criteria to project a pseudo-upwind point source. Line sources are generated along the route of travel of

  3. The Upsilon Pegasid Meteor Shower

    NASA Astrophysics Data System (ADS)

    Povenmire, H.

    1995-09-01

    On the morning of August 8, 1975, meteors were observed from a previously unrecognized radiant in Pegasus. The rates were approximately seven per hour [1]. The radiant was alpha = 350 degrees, delta = +19 degrees (2000.0). These meteors are characterized as swift, yellow-white and without significant ionization trains [1]. The average magnitude of several hundred meteors from this shower is approximately +3.50, slightly fainter than the Perseids which occur at the same time. A broad maximum seems to occur about August 8. The three active fireball networks (Prairie, MORP and European) were contacted in a search for previously recorded fireballs with negative results. Ceplecha [2] of the European Network computed the orbital elements using the FIRBAL program. On August 19, 1982 at 02:09:57 UT, a magnitude -14.76 f1reball occurred over the White Carpathian Mountains of Austria and Czechoslovakia. It was photographed by five cameras of the European Network. Reduction of this Upsilon Pegasid fireball (EN 190882A) showed it to be a type IIIb fireball [2] - that is, an extremely low density, cometary, snow-like material with a specific gravity of approximately 0.27 g/cm^3. This material ablates at high altitude and cannot produce sonic phenomena or meteorites. It is similar to the material in the Draconid meteor shower. The orbital elements derived from EN 190882A are given in Table I. Table I: Orbital elements for the Upsilon Pegasid stream from EN 190882A. omega = 305.9009 degrees Omega = 145.3431 degrees i = 85.0817 degrees q = 0.2022 e = 1.0 velocity = 51.8608 km/s Using these refined elements, Kronk [3] computed the radiant drift. The radiant drifts from the SSW to NNE at a relatively steep angle and at an average rate of 20 arc-min per day. An intensive literature search [3] revealed four double station Upsilon Pegasids which had previously been listed as sporadics. Institutions providing these data were Yale [4], Stalinabad [5], Tadjikistan [6] and Harvard [7

  4. 40 CFR 60.2706 - By what date must I conduct the initial air pollution control device inspection?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air pollution control device inspection? 60.2706 Section 60.2706 Protection of Environment... pollution control device inspection? (a) The initial air pollution control device inspection must be... meeting the amended emission limitations. (b) Within 10 operating days following an air pollution...

  5. 40 CFR 60.2706 - By what date must I conduct the initial air pollution control device inspection?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air pollution control device inspection? 60.2706 Section 60.2706 Protection of Environment... pollution control device inspection? (a) The initial air pollution control device inspection must be... meeting the amended emission limitations. (b) Within 10 operating days following an air pollution...

  6. 40 CFR 60.2706 - By what date must I conduct the initial air pollution control device inspection?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air pollution control device inspection? 60.2706 Section 60.2706 Protection of Environment... pollution control device inspection? (a) The initial air pollution control device inspection must be... meeting the amended emission limitations. (b) Within 10 operating days following an air pollution...

  7. Search for excess showers from Crab Nebula

    NASA Technical Reports Server (NTRS)

    Kirov, I. N.; Stamenov, J. N.; Ushev, S. Z.; Janminchev, V. D.; Aseikin, V. S.; Nikolsky, S. I.; Nikolskaja, N. M.; Yakovlev, V. I.; Morozov, A. E.

    1985-01-01

    The arrival directions of muon poor showers registrated in the Tien Shan experiment during an effective running time about I,8.IO(4)h were analyzed. It is shown that there is a significant excess of these showers coming the direction of Crab Nebula.

  8. Ice surface roughness modeling for effect on radio signals from UHE particle showers

    NASA Astrophysics Data System (ADS)

    Stockham, Jessica

    2014-03-01

    For radio antenna detectors located in or above the Antarctic ice sheet, the reconstruction of both ultra-high energy (UHE) neutrino and cosmic ray air shower events requires understanding the transmission and reflection properties of the air-ice interface. To this end, surface and volume scattering from granular materials in the microwave frequency range are measured and stereoscopic images of the ice surface, obtained by the Antarctric Geophysics Along the Vostok Expedition (AGAVE), are used to determine the 3D surface structure. This data is implemented to determine an appropriate model for use in simulation and data analysis of the shower events. ANtarctic Impulsive Transient Antenna.

  9. Meteor Shower Identification and Characterization with Python

    NASA Technical Reports Server (NTRS)

    Moorhead, Althea

    2015-01-01

    The short development time associated with Python and the number of astronomical packages available have led to increased usage within NASA. The Meteoroid Environment Office in particular uses the Python language for a number of applications, including daily meteor shower activity reporting, searches for potential parent bodies of meteor showers, and short dynamical simulations. We present our development of a meteor shower identification code that identifies statistically significant groups of meteors on similar orbits. This code overcomes several challenging characteristics of meteor showers such as drastic differences in uncertainties between meteors and between the orbital elements of a single meteor, and the variation of shower characteristics such as duration with age or planetary perturbations. This code has been proven to successfully and quickly identify unusual meteor activity such as the 2014 kappa Cygnid outburst. We present our algorithm along with these successes and discuss our plans for further code development.

  10. Meteor showers associated with 2003EH1

    NASA Astrophysics Data System (ADS)

    Babadzhanov, P. B.; Williams, I. P.; Kokhirova, G. I.

    2008-06-01

    Using the Everhart RADAU19 numerical integration method, the orbital evolution of the near-Earth asteroid 2003EH1 is investigated. This asteroid belongs to the Amor group and is moving on a comet-like orbit. The integrations are performed over one cycle of variation of the perihelion argument ω. Over such a cycle, the orbit intersect that of the Earth at eight different values of ω. The orbital parameters are different at each of these intersections and so a meteoroid stream surrounding such an orbit can produce eight different meteor showers, one at each crossing. The geocentric radiants and velocities of the eight theoretical meteor showers associated with these crossing points are determined. Using published data, observed meteor showers are identified with each of the theoretically predicted showers. The character of the orbit and the existence of observed meteor showers associated with 2003EH1 confirm the supposition that this object is an extinct comet.

  11. Air Quality in Mecca and Surrounding Holy Places in Saudi Arabia during Hajj: Initial Survey

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Aburizaiza, O. S.; Siddique, A.; Barletta, B.; Blake, N. J.; Gartner, A.; Khwaja, H. A.; Meinardi, S.; Zeb, J.; Blake, D. R.

    2014-12-01

    The Arabian Peninsula experiences severe air pollution yet is highly understudied in terms of surface measurements of ozone and its precursors. Every year the air pollution in Saudi Arabia is intensified by additional traffic and activities during Hajj, the world's largest religious pilgrimage that draws 3‒4 million pilgrims to Mecca (population of 2 million). Using whole air sampling and high-precision measurements of carbon monoxide (CO) and 97 volatile organic compounds (VOCs), we performed an initial survey of air quality in Mecca, its tunnels, and surrounding holy sites during the 2012 Hajj (October 24-27; n = 77). This is the first time such a campaign has been undertaken. Levels of the combustion tracer CO and numerous VOCs were strongly elevated along the pilgrimage route, especially in the tunnels of Mecca, and are a concern for human health. For example CO reached 57 ppmv in the tunnels, exceeding the 30-min exposure guideline of 50 ppmv. Benzene, a known carcinogen, reached 185 ppbv in the tunnels, exceeding the 1-hr exposure limit of 9 ppbv. The gasoline evaporation tracer i-pentane was the most abundant VOC during Hajj, reaching 1200 ppbv in the tunnels. Even though VOC concentrations were generally lower during a follow-up non-Hajj sampling period (April, 2013), many were still comparable to other large cities suffering from poor air quality. Major VOC sources during Hajj included vehicular exhaust, gasoline evaporation, liquefied petroleum gas, and air conditioners. Of the measured compounds, reactive alkenes (associated with gasoline evaporation) and CO showed the strongest potential to form ground-level ozone. Therefore efforts to curb ozone formation likely require dual targeting of both combustive and evaporative fossil fuel sources. However, modeling and other measurements (e.g., nitrogen oxides) are also needed to fully understand Mecca's oxidative environment. We also present specific recommendations to reduce VOC emissions and exposure in

  12. Comparison of hybrid and pure Monte Carlo shower generators on an event by event basis

    NASA Astrophysics Data System (ADS)

    Allen, J.; Drescher, H.-J.; Farrar, G.

    SENECA is a hybrid air shower simulation written by H. Drescher that utilizes both Monte Carlo simulation and cascade equations. By using the cascade equations only in the high energy portion of the shower, where they are extremely accurate, SENECA is able to utilize the advantages in speed from the cascade equations yet still produce complete, three dimensional particle distributions at ground level. We present a comparison, on an event by event basis, of SENECA and CORSIKA, a well trusted MC simulation. By using the same first interaction in both SENECA and CORSIKA, the effect of the cascade equations can be studied within a single shower, rather than averages over many showers. Our study shows that for showers produced in this manner, SENECA agrees with CORSIKA to a very high accuracy as to densities, energies, and timing information for individual species of ground-level particles from both iron and proton primaries with energies between 1EeV and 100EeV. Used properly, SENECA produces ground particle distributions virtually indistinguishable from those of CORSIKA in a fraction of the time. For example, for a shower induced by a 40 EeV proton simulated with 10-6 thinning, SENECA is 10 times faster than CORSIKA.

  13. Using water to cool cattle: behavioral and physiological changes associated with voluntary use of cow showers.

    PubMed

    Legrand, A; Schütz, K E; Tucker, C B

    2011-07-01

    Water is commonly used to cool cattle in summer either at milking or over the feed bunk, but little research has examined how dairy cows voluntarily use water separate from these locations. The objectives were to describe how and when dairy cattle voluntarily used an overhead water source separate from other resources, such as feed, and how use of this water affected behavioral and physiological indicators of heat stress. Half of the 24 nonlactating cattle tested had access to a "cow shower" composed of 2 shower heads activated by a pressure-sensitive floor. All animals were individually housed to prevent competition for access to the shower. Over 5 d in summer (air temperature=25.3±3.3°C, mean ± standard deviation), cattle spent 3.0±2.1 h/24h in the shower, but considerable variability existed between animals (individual daily values ranged from 0.0 to 8.2 h/24h). A portion of this variation can be explained by weather; shower use increased by 0.3h for every 1°C increase in ambient temperature. Cows preferentially used the shower during the daytime, with 89±12% of the time spent in the shower between 1000 and 1900 h. Respiration rate and skin temperature did not differ between treatments [53 vs. 61 breaths/min and 35.0 vs. 35.4°C in shower and control cows, respectively; standard error of the difference (SED)=5.6 breaths/min and 0.49°C]. In contrast, body temperature of cows provided with a shower was 0.2°C lower than control cows in the evening (i.e., 1800 to 2100h; SED=0.11°C). Cows with access to a shower spent half as much time near the water trough than control animals, and this pattern became more pronounced as the temperature-humidity index increased. In addition, cattle showed other behavioral changes to increasing heat load; they spent less time lying when heat load index increased, but the time spent lying, feeding, and standing without feeding did not differ between treatments. Cows had higher respiration rate, skin temperature, and body

  14. Meteor showers of the southern hemisphere

    NASA Astrophysics Data System (ADS)

    Molau, Sirko; Kerr, Steve

    2014-04-01

    We present the results of an exhaustive meteor shower search in the southern hemisphere. The underlying data set is a subset of the IMO Video Meteor Database comprising 50,000 single station meteors obtained by three Australian cameras between 2001 and 2012. The detection technique was similar to previous single station analysis. In the data set we find 4 major and 6 minor northern hemisphere meteor showers, and 12 segments of the Antihelion source (including the Northern and Southern Taurids and six streams from the MDC working list). We present details for 14 southern hemisphere showers plus the Centaurid and Puppid-Velid complex, with the η Aquariids and the Southern δ Aquariids being the strongest southern showers. Two of the showers (θ^2 Sagittariids and τ Cetids) were previously unknown and have received preliminary designations by the MDC. Overall we find that the fraction of southern meteor showers south of -30deg declination (roughly 25%) is clearly smaller than the fraction of northern meteor showers north of +30deg declination (more than 50%) obtained in our previous analysis.

  15. Prediction of free air space in initial composting mixtures by a statistical design approach.

    PubMed

    Soares, Micaela A R; Quina, Margarida J; Quinta-Ferreira, Rosa

    2013-10-15

    Free air space (FAS) is a physical parameter that can play an important role in composting processes to maintain favourable aerobic conditions. Aiming to predict the FAS of initial composting mixtures, specific materials proportions ranged from 0 to 1 were tested for a case study comprising industrial potato peel, which is characterized by low air void volume, thus requiring additional components for its composting. The characterization and prediction of FAS for initial mixtures involving potato peel, grass clippings and rice husks (set A) or sawdust (set B) was accomplished by means of an augmented simplex-centroid mixture design approach. The experimental data were fitted to second order Scheffé polynomials. Synergistic or antagonistic effects of mixture proportions in the FAS response were identified from the surface and response trace plots in the FAS response. Moreover, a good agreement was achieved between the model predictions and supplementary experimental data. Moreover, theoretical and empirical approaches for estimating FAS available in literature were compared with the predictions generated by the mixture design approach. This study demonstrated that the mixture design methodology can be a valuable tool to predict the initial FAS of composting mixtures, specifically in making adjustments to improve composting processes containing primarily potato peel.

  16. Design, fabrication and acceptance testing of a zero gravity whole body shower, volume 1

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The effort to design whole body shower for the space station prototype is reported. Clothes and dish washer/dryer concepts were formulated with consideration given to integrating such a system with the overall shower design. Water recycling methods to effect vehicle weight savings were investigated and it was concluded that reusing wash and/or rinse water resulted in weight savings which were not sufficient to outweigh the added degree of hardware complexity. The formulation of preliminary and final designs for the shower are described. A detailed comparison of the air drag vs. vacuum pickup method was prepared that indicated the air drag concept results in more severe space station weight penalties; therefore, the preliminary system design was based on utilizing the vacuum pickup method. Tests were performed to determine the optimum methods of storing, heating and sterilizing the cleansing agent utilized in the shower; it was concluded that individual packages of pre-sterilized cleansing agent should be used. Integration features with the space station prototype system were defined and incorporated into the shower design as necessary.

  17. Detection threshold energy of high energy cascade showers using thermoluminescence PTFE-sheet and hot-gas reader

    NASA Technical Reports Server (NTRS)

    Kino, S.; Nakanishi, A.; Miono, S.; Kitajima, T.; Yanagita, T.; Nakatsuka, T.; Ohmori, N.; Hazama, M.

    1985-01-01

    A new thermoluminescence (TL) sheet was developed as a detector for high energy components in air showers. For the investigation of detection threshold energy for a cascade showeer, TL sheets were exposed at Mt. Fuji with X ray films in emulsion chambers and were scanned by a hot-gas reader. It is concluded that if a gamma ray whose energy is more than 6 TeV enters vertically into lead chambers, the resulting cascade shower is readily detectable at maximum development.

  18. Kinetic theory of runaway air breakdown and the implications for lightning initiation

    SciTech Connect

    Roussel-Dupre, R.A.; Gurevich, A.V.; Tunnell, T.; Milikh, G.M.

    1993-11-01

    The kinetic theory for a new air breakdown mechanism advanced in a previous paper is developed. The relevant form of the Boltzmann equation is derived and the particle orbits in both velocity space and configuration space are computed. A numerical solution of the Boltzmann equation, assuring a spatially uniform electric field, is obtained and the temporal evolution of the electron velocity distribution function is described. The results of our analysis are used to estimate the magnitude of potential x-ray emissions from discharges in thunderstorms and are examined in the context of lightning initiation.

  19. 49 CFR 228.321 - Showering facilities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... provided with hot and cold water feeding a common discharge line. (3) Unless otherwise provided by a... and cold running potable water must be provided for showering purposes. The water supplied to a...

  20. 49 CFR 228.321 - Showering facilities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... provided with hot and cold water feeding a common discharge line. (3) Unless otherwise provided by a... and cold running potable water must be provided for showering purposes. The water supplied to a...

  1. Initial results of an ensemble data assimilation system for a hemispheric air quality model

    NASA Astrophysics Data System (ADS)

    Silver, J. D.; Brandt, J.; Christensen, J. H.

    2012-04-01

    Data assimilation can be used with air quality models to improve historical simulations or initial conditions for forecasts. The ensemble Kalman filter is an assimilation technique that uses a low-dimensional representation of the background error covariances. We have coupled an offline chemical transport model, the DEHM (the Danish Eulerian hemispheric model), with an asynchronous ensemble Kalman filter (AEnKF), which accounts for timing discrepancies between observation and the analysis time. We will present the structure and initial results using this simulation-assimilation framework. To evaluate the DEHM-AEnKF system, we assimilated a single species, carbon monoxide. Carbon monoxide is a moderately long-lived atmospheric trace gas, and its concentration is measured routinely from a number of different measurement platforms. The chemistry of CO is simpler than other well-studied species (e.g., ozone). Thus CO is a good candidate species for the initial testing of a chemical data assimilation system. We assimilated retrieved CO column concentrations from MOPITT (an instrument aboard the polar orbiting NASA satellite Terra) and from surface measurements from the Global Atmosphere Watch monitoring network. Simulations were evaluated against measurements from the AirBase network of European monitoring stations. The initial results show that the simulations without assimilation grossly underestimate surface CO concentrations, and the DEHM-AEnKF system eliminates this large and systematic bias. Furthermore, the temporal variability of the DEHM-AEnKF CO concentrations were far more consistent with surface measurements (compared to the simulations without assimilation). While these preliminary results are promising, this is a single-species assimilation for a moderately long-lived atmospheric trace gas, and thus represents a relatively simple assimilation challenge. We will discuss how the DEHM-AEnKF system can be scaled to accommodate multi-species assimilation, as

  2. Structural peculiarities of the Quadrantid meteor shower

    NASA Technical Reports Server (NTRS)

    Isamutdinov, Sh. O.; Chebotarev, R. P.

    1987-01-01

    Systematic radio observations to investigate the Quadrantid meteor shower structure are regularly carried out. They have now been conducted annually in the period of its maximum activity, January 1 to 6, since 1966. The latest results of these investigations are presented, on the basis of 1981 to 1984 data obtained using new equipment with a limiting sensitivity of +7.7 sup m which make it possible to draw some conclusions on the Quadrantids shower structure both for transverse and lengthwise directions.

  3. Note on the 1972 Giacobinid meteor shower.

    NASA Technical Reports Server (NTRS)

    Harvey, G. A.

    1973-01-01

    It is shown that the 1972 Giacobinid meteor shower was extremely weak with a peak activity of two to three visual meteors per hour. Only two meteor spectra were obtained from the 17 slitless spectrograph systems operated by the Langley Research Center. The largely unexpected, essentially null results of the 1972 Giacobinid meteor shower observations are indicative of the present limited understanding and predictability of cosmic dust storms.

  4. Initial Results from the ANITA 2006-2007 Balloon Flight

    SciTech Connect

    Gorham, P.W.; Allison, P.; Barwick, S.W.; Beatty, J.J.; 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.; Goodhue, A.; Hast, C.; Hebert, C.L.; Hoover, S.; Israel, M.H.; Kowalski, J.; Learned, J.G.; /Hawaii U. /Caltech, JPL /Hawaii U. /Minnesota U. /Hawaii U. /Ohio State U. /Hawaii U. /Hawaii U. /UC, Irvine /Taiwan, Natl. Taiwan U. /Caltech, JPL /SLAC /University Coll. London /Ohio State U. /SLAC /Hawaii U. /Hawaii U. /Hawaii U. /UCLA /Delaware U. /Hawaii U. /SLAC /Taiwan, Natl. Taiwan U. /UC, Irvine

    2011-11-16

    We report initial results of the Antarctic Impulsive Transient Antenna (ANITA) 2006-2007 Long Duration Balloon flight, which searched for evidence of the flux of cosmogenic neutrinos. ANITA flew for 35 days looking for radio impulses that might be due to the Askaryan effect in neutrino-induced electromagnetic showers within the Antarctic ice sheets. In our initial high-threshold robust analysis, no neutrino candidates are seen, with no physics background. In a non-signal horizontal-polarization channel, we do detect 6 events consistent with radio impulses from extensive air showers, which helps to validate the effectiveness of our method. Upper limits derived from our analysis now begin to eliminate the highest cosmogenic neutrino models.

  5. EPA Finalizes Initial Area Designations for the 2012 National Air Quality Standard for Fine Particles - Dec 2014

    EPA Pesticide Factsheets

    After considering state and tribal recommendations, reviewing the most recent certified fine particle air quality data, and emissions that contribute fine particle pollution, EPA has completed initial designations for the 2012 annual fine particle standard

  6. Periodic cometary showers: Real or imaginary?

    NASA Technical Reports Server (NTRS)

    Grieve, R. A. F.; Sharpton, V. L.; Goodacre, A. K.; Garvin, J. B.

    1985-01-01

    Since the initial reports in 1980, a considerable body of chemical and physical evidence has been accumulated to indicate that a major impact event occurred on earth 65 million years ago. The effects of this event were global in extent and have been suggested as the cause of the sudden demise or mass extinction of a large percentage of life, including the dinosaurs, at the end of the geologic time period known as the Cretaceous. Recent statistical analyses of extinctions in the marine faunal record for the last 250 million years have suggested that mass extinctions may occur with a periodicity of every 26 to 30 million years. Following these results, other workers have attempted to demonstrate that these extinction events, like that at the end of the Cretaceous, are temporally correlated with large impact events. A recent scenario suggests that they are the result of periodic showers of comets produced by either the passage of the solar system through the galactic plane or by perturbations of the cometary cloud in the outer solar system by a, as yet unseen, solar companion. This hypothesized solar companion has been given the name Nemesis.

  7. Secondary organic aerosol formation initiated by α-terpineol ozonolysis in indoor air.

    PubMed

    Yang, Y; Waring, M S

    2016-12-01

    Secondary organic aerosol (SOA) owing to reactive organic gas (ROG) ozonolysis can be an important indoor particle source. However, SOA formation owing to ozonolysis of α-terpineol, which is emitted by consumer product usage and reacts strongly with ozone, has not been systematically quantified. Therefore, we conducted 21 experiments to investigate the SOA formation initiated by α-terpineol ozonolysis for high (0.84 h(-1) ), moderate (0.61 h(-1) ), and low (0.36 h(-1) ) air exchange rates (AER), which is the frequency with which indoor is replaced by outdoor air. α-Terpineol concentrations of 6.39 to 226 ppb were combined with high ozone (~25 ppm) to ensure rapid and complete ozonolysis. No reactants were replenished, so SOA peaked quickly and then decreased due to AER and surface losses, and peak SOA ranged from 2.03 to 281 μg/m(3) at unit density. SOA mass formation was parameterized with the aerosol mass fraction (AMF), a.k.a. the SOA yield, and AMFs ranged from 0.056 to 0.24. The AMFs strongly and positively correlated with reacted α-terpineol, whereas they weakly and negatively correlated with higher AERs. One-product, two-product, and volatility basis set (VBS) models were fit to the AMF data. Predictive modeling demonstrated that α-terpineol ozonolysis could meaningfully form SOA in indoor air.

  8. NASA's East and Southeast Asia Initiatives: BASE-ASIA and EAST-AIRE

    NASA Technical Reports Server (NTRS)

    Tsay, S.; Maring, H.

    2005-01-01

    Airborne dust from northern China influences air quality and regional climate in Asia during springtime. However, with the economic growth in China, increased emission of particulate air pollutants from industrial and vehicular sources will not only impact the earth's radiation balance, but also adversely affect human health year round. In addition, both of dust and aerosol pollutants can be transported swiftly across the Pacific affecting North America within a few days. Asian dust and pollutant aerosols can be detected by their colored appearance using current Earth observing satellites (e.g., MODIS, SeaWiFS, TOMS, etc.) and by sunphotometers deployed on the surface of the earth. Biomass burning has been a regular practice for land clearing and conversion in many countries, especially those in Africa, South America, and Southeast Asia. However, the climatology of Southeast Asia is very different than that of Africa and South America, such that large-scale biomass burning causes smoke to interact extensively with clouds during the peak-burning season of March to April. Globally significant sources of greenhouse gases (eg., CO2, CH4), chemically active gases (e.g., NO, CO, HC, CH3Br), and atmospheric aerosols are produced by biomass burning. These gases influence the Earth-atmosphere system, impacting both global climate and tropospheric chemistry. Some aerosols can serve as cloud condensation nuclei, which play a role in determining cloud lifetime and precipitation, altering the earth's radiation and water budgets. Biomass burning also affects the biogeochemical cycling of nitrogen and carbon compounds; the hydrological cycle; land surface reflectivity and emissivity; and ecosystem biodiversity and stability. Two NASA initiatives, EAST-AIRE (East Asian Study of Tropospheric Aerosols: an International Regional Experiment) and BASE-ASIA (Biomass-burning Aerosols in South East-Asia: Smoke Impact Assessment) will be presented. The objectives of these initiatives is to

  9. Focused excimer laser initiated, radio frequency sustained high pressure air plasmas

    SciTech Connect

    Giar, Ryan; Scharer, John

    2011-11-15

    Measurements and analysis of air breakdown processes and plasma production by focusing 193 nm, 300 mJ, 15 MW high power laser radiation inside a 6 cm diameter helical radio frequency (RF) coil are presented. Quantum resonant multi-photon ionization (REMPI) and collisional cascade laser ionization processes are exploited that have been shown to produce high-density (n{sub e} {approx} 7 x 10{sup 16}/cm{sup 3}) cylindrical seed plasmas at 760 Torr. Air breakdown in lower pressures (from 7-22 Torr), where REMPI is the dominant laser ionization process, is investigated using an UV 18 cm focal length lens, resulting in a laser flux of 5.5 GW/cm{sup 2} at the focal spot. The focused laser power absorption and associated shock wave produce seed plasmas for sustainment by the RF (5 kW incident power, 1.5 s) pulse. Measurements of the helical RF antenna load impedance in the inductive and capacitive coupling regimes are obtained by measuring the loaded antenna reflection coefficient. A 105 GHz interferometer is used to measure the plasma electron density and collision frequency. Spectroscopic measurements of the plasma and comparison with the SPECAIR code are made to determine translational, rotational, and vibrational neutral temperatures and the associated neutral gas temperature. From this and the associated measurement of the gas pressure the electron temperature is obtained. Experiments show that the laser-formed seed plasma allows RF sustainment at higher initial air pressures (up to 22 Torr) than that obtained via RF-only initiation (<18 Torr) by means of a 0.3 J UV laser pulse.

  10. Gulf of Mexico Air/Sea Interaction: Measurements and Initial Data Characterization

    NASA Astrophysics Data System (ADS)

    MacDonald, C.; Huang, C. H.; Roberts, P. T.; Bariteau, L.; Fairall, C. W.; Gibson, W.; Ray, A.

    2011-12-01

    Corporate, government, and university researchers collaborated to develop an atmospheric boundary layer environmental observations program on an offshore platform in the Gulf of Mexico. The primary goals of this project were to provide data to (1) improve our understanding of boundary layer processes and air-sea interaction over the Gulf of Mexico; (2) improve regional-scale meteorological and air quality modeling; and (3) provide a framework for advanced offshore measurements to support future needs such as emergency response, exploration and lease decisions, wind energy research and development, and meteorological and air quality forecasting. In October 2010, meteorological and oceanographic sensors were deployed for an extended period (approximately 12 months) on a Chevron service platform (ST 52B, 90.5W, 29N) to collect boundary layer and sea surface data sufficient to support these objectives. This project has significant importance given the large industrial presence in the Gulf, sizeable regional population nearby, and the recognized need for precise and timely pollutant forecasts. Observations from this project include surface meteorology; sodar marine boundary layer winds; microwave radiometer profiles of temperature, relative humidity, and liquid water; ceilometer cloud base heights; water temperature and current profiles; sea surface temperature; wave height statistics; downwelling solar and infrared radiation; and air-sea turbulent momentum and heat fluxes. This project resulted in the collection of an unprecedented set of boundary layer measurements over the Gulf of Mexico that capture the range of meteorological and oceanographic interactions and processes that occur over an entire year. This presentation will provide insight into the logistical and scientific issues associated with the deployment and operations of unique measurements in offshore areas and provide results from an initial data analysis of boundary layer processes over the Gulf of

  11. Zero liquid carryover whole-body shower vortex liquid/gas separator

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The development and evaluation of a liquid/gas vortex type separator design eliminating liquid and semi-liquid (suds) carryover into air recirculating system were described. Consideration was given to a number of soaps other than the "Miranol JEM" which was the low sudsing soap used in previous test runs of the space shower. Analysis of test parameters and prototype testing resulted in a revised separator configuration and a better understanding of the suds generating mechanism in the wastewater collection system. The final design of the new separator provides for a wider choice of soaps without leading to the problem of "carryover". Furthermore, no changes in separator-to-shower interfaces were required. The new separator was retrofitted on the "space shower" and satisfactorily demonstrated in one-g testing.

  12. Determination of burst initiation location and tear propagation velocity during air burst testing of latex condoms

    NASA Astrophysics Data System (ADS)

    Davidhazy, Andrew

    1991-04-01

    The stress testing of latex condoms by an air burst procedure has been slow in gaining industry acceptance because questions have been raised regarding the influence of the test apparatus on the likelihood of breakage occurring where the condom is attached to the inflation device. It was desired to locate the areas at which the condoms tend to burst and thus corroborate or disprove these claims. Several factors associated with the bursting condom demanded the use of special instrumentation to detect arid study the burst initiation process. Microsecond duration electronic flashes were used for the initial stages of the investigation. Although the absolute point of initiation of a given burst could not be photographed, these high speed studies tend to indicate that the most likely place for high quality condoms to break is not where they are attached to the inflation device but at an intermediate area between the base and the tip of the condom. In addition, tear propagation characteristics and velocities were determined with a delayed-flash technique, a double-slit strip method and a rotating drum framing camera.

  13. Statistical analyses of the U.S. Air Force Bioventing Initiative results

    SciTech Connect

    Leeson, A.; Kumar, P.; Hinchee, R.E.; Downey, D.; Vogel, C.M.; Sayles, G.D.; Miller, R.N.

    1995-12-31

    The US Air Force`s Bioventing Initiative has involved conducting field treatability studies to evaluate bioventing feasibility at more than 120 sites throughout the US. At those sites where feasibility studies produced positive results, pilot-scale bioventing systems were installed and operated for 1 year. The results from the pilot-scale bioventing systems have been used to develop a large database from which to determine the most important parameters to be used in evaluating whether to implement bioventing. Data generated from the Bioventing Initiative were subjected to a thorough statistical analysis to determine which parameters correlate with BTEX and TPH biodegradation rates. The study involved in situ respiration test data, soil gas permeability test data, and soil chemistry and nutrient data from each site. Results from the Bioventing Initiative demonstrated that some biodegradation occurred at virtually all sites regardless of site conditions. Data collected from the sites demonstrate that even sites with low nutrient levels exhibit significant microbial activity and will therefore respond well to bioventing.

  14. Lateral distribution and the energy determination of showers along the ankle

    NASA Astrophysics Data System (ADS)

    Ros, G.; Medina-Tanco, G.A.; De Donato, C.; del Peral, L.; Rodríguez-Frías, D.; D'Olivo, J.C.; Valdés-Galicia, J.F.; Arqueros, F.

    The normalization constant of the lateral distribution function (LDF) of an extensive air shower is a monotonous (almost linear) increasing function of the energy of the primary, as well as a monotonous decreasing function of the distance from the shower core. Therefore, the interpolated signal at some fixed distance from the core can be calibrated to estimate the energy of the shower. There is, somehow surprisingly, a reconstructed optimal distance, r_opt, at which the effects on the inferred signal, S(r_opt), of the uncertainties on true core location, LDF functional form and shower-to-shower fluctuations are minimized. We calculate the value of r_opt and study the robustness of the method as a function of surface detector separation (400 m to 1500 m), energy (0.1 EeV to 10 EeV) and zenith angle (0 to 60 deg) for a realistic distribution of core determination errors along the space parameter used. We also investigate the effects of silent and saturated stations and give a rough estimate of the systematic errors introduced by varying cosmic ray composition inside the considered energy range.

  15. The Green Heart Initiative: Using Air Quality Information to Reduce Adverse Health Effects in Patients with Heart and Vascular Disease

    EPA Science Inventory

    The Green Heart Initiatives designed to raise public awareness about the role outdoor air pollution plays in cardiovascular health. Developed by the U.S. Environmental Protection Agency (EPA) to complement the national Million Hearts” initiative1, Green Heart seeks to teach healt...

  16. Analysis of air pollution and greenhouse gases. Initial studies, FY 1991

    SciTech Connect

    Benkovitz, C.M.

    1992-03-01

    The current objective of the project ``Analysis of Air Pollution and Greenhouse Gases`` is to develop a study of emissions and emission sources that could easily be linked to models of economic activity. Initial studies were conducted to evaluate data currently available linking activity rates and emissions estimates. The emissions inventory developed for the National Acid Precipitation Assessment Program (NAPAP) presents one of the most comprehensive data sets, and was chosen for our initial studies, which are described in this report. Over 99% of the SO{sub 2} emissions, 98% of the NO{sub x} emission and 57% of the VOC emissions from area sources are related to fuel combustion. The majority of emission from these sources are generated by the transportation sector. Activity rates for area sources are not archived with the NAPAP inventory; alternative derivations of these data will be part of the future activities of this project. The availability and completeness of the fuel heat content data in the NAPAP inventory were also studied. Approximately 10% of the SO{sub 2} emissions, 13% of the NO{sub x} emissions and 46% of the VOC emissions are generated by sources with unavailable data for fuel heat content. Initial estimates of pollutant emission rate per unit fuel heat content. Initial estimates of pollutant emission rate per unit fuel heat content were generated. Future studies for this project include the derivation of activity rates for area sources, improved explanations for the default fuel parameters defined in the NAPAP inventory and the development of links to data bases of economic activity.

  17. Streamer-to-spark transition initiated by a nanosecond overvoltage pulsed discharge in air

    NASA Astrophysics Data System (ADS)

    Lo, A.; Cessou, A.; Lacour, C.; Lecordier, B.; Boubert, P.; Xu, D. A.; Laux, C. O.; Vervisch, P.

    2017-04-01

    This study is focused on the streamer-to-spark transition generated by an overvoltage nanosecond pulsed discharge under atmospheric pressure air in order to provide a quantitative insight into plasma-assisted ignition. The discharge is generated in atmospheric pressure air by the application of a positive high voltage pulse of 35 kV to pin-to-pin electrodes and a rise time of 5 ns. The generated discharge consists of a streamer phase with high voltage and high current followed by a spark phase characterized by a low voltage and a decreasing current in several hundreds of nanosecond. During the streamer phase, the gas temperature measured by optical emission spectroscopy related to the second positive system of nitrogen shows an ultra-fast gas heating up to 1200 K at 15 ns after the current rise. This ultra-fast gas heating, due to the quenching of electronically excited species by oxygen molecules, is followed by a quick dissociation of molecules and then the discharge transition to a spark. At this transition, the discharge contracts toward the channel axis and evolves into a highly conducting thin column. The spark phase is characterized by a high degree of ionization of nitrogen and oxygen atoms shown by the electron number density and temperature measured from optical emission spectroscopy measurements of N+ lines. Schlieren imaging and optical emission spectroscopy techniques provide the time evolution of the spark radius, from which the initial pressure in the spark is estimated. The expansion of the plasma is adiabatic in the early phase. The electronic temperature and density during this phase allows the determination of the isentropic coefficient. The value around 1.2–1.3 is coherent with the high ionization rate of the plasma in the early phase. The results obtained in this study provide a database and the initial conditions for the validation of numerical simulations of the ignition by plasma discharge.

  18. Effects of room temperature on physiological and subjective responses during whole-body bathing, half-body bathing and showering.

    PubMed

    Hashiguchi, Nobuko; Ni, Furong; Tochihara, Yutaka

    2002-11-01

    The effects of bathroom thermal conditions on physiological and subjective responses were evaluated before, during, and after whole-body bath (W-bath), half-body bath (H-bath) and showering. The air temperature of the dressing room and bathroom was controlled at 10 degrees C, 17.5 degrees C, and 25 degrees C. Eight healthy males bathed for 10 min under nine conditions on separate days. The water temperature of the bathtub and shower was controlled at 40 degrees C and 41 degrees C, respectively. Rectal temperature (Tre), mean skin temperature (Tsk), blood pressure (BP), heart rate (HR), body weight loss and blood characteristics (hematocrit: Hct, hemoglobin: Hb) were evaluated. Also, thermal sensation (TS), thermal comfort (TC) and thermal acceptability (TA) were recorded. BP decreased rapidly during W-bath and H-bath compared to showering. HR during W-bath was significantly higher than for H-bath and showering (p < 0.01). The double products due to W-bath during bathing were also greater than for H-bath and showering (p < 0.05). There were no distinct differences in Hct and Hb among the nine conditions. However, significant differences in body weight loss were observed among the bathing methods: W-bath > H-bath > showering (p < 0.001). W-bath showed the largest increase in Tre and Tsk, followed by H-bath, and showering. Significant differences in Tre after bathing among the room temperatures were found only at H-bath. The changes in Tre after bathing for H-bath at 25 degrees C were similar to those for W-bath at 17.5 degrees C and 10 degrees C. TS and TC after bathing significantly differed for the three bathing methods at 17.5 degrees C and 10 degrees C (TS: p < 0.01 TC: p < 0.001). Especially, for showering, the largest number of subjects felt "cold" and "uncomfortable". Even though all of the subjects could accept the 10 degrees C condition after W-bath, such conditions were intolerable to half of them after showering. These results suggested that the

  19. The initial generation of waves in an accelerated coupled air-water flow.

    NASA Astrophysics Data System (ADS)

    Veron, Fabrice; Ierley, Glenn; Melville, Ken

    2001-11-01

    The initial generation of surface waves over the ocean has a long been a problem of great interest. With the globally averaged wind speed in the range 6-7 m/s, and 40 % of the time below 6 m/s, much of the air-sea interface is in a low wind speed regime, and therefore the initial generation of waves under these conditions is of special interest. There is also a transition in the surface heat flux and surface cool skin at these low wind speeds when gravity capillary waves are first generated. We present the results of laboratory and field experiments, and numerical studies, on the stability of a wind-driven water surface to the initial generation of surface waves. Using modern quantitative flow visualization techniques, we show that the classical wave generation problem, where the wind is linearly accelerated over a still water surface, leads to the generation of a two-dimensional wave field. At this stage, the flow in the water phase has been observed to be sub-critical. These results are compared with numerical solutions of the stability of the coupled air-water problem obtained by solving both the linear and non-linear Orr-Sommerfeld coupled equations. The effects of non-linearity will be discussed. In addition, we show that the wave generation problem is accompanied by the turbulent transition of the water surface boundary layer through the formation and dislocation of Langmuir circulations. Field data suggest that this transition, rather than microscale breaking waves, first disrupt the cool skin. We show that this turbulent transition also marks the change from a two- to three-dimensional surface wave field as the coherent sub-surface velocities modulate the waves. This rapid evolution from 2D to 3D surface wave patterns in the early stages of the wave generation implies that 2D models for wind-wave generation might only apply in the very early stages of wave growth. This will be discussed in light of linear and non-linear wave generation models.

  20. THE RETURN OF THE ANDROMEDIDS METEOR SHOWER

    SciTech Connect

    Wiegert, Paul A.; Brown, Peter G.; Weryk, Robert J.; Wong, Daniel K.

    2013-03-15

    The Andromedid meteor shower underwent spectacular outbursts in 1872 and 1885, producing thousands of visual meteors per hour and described as ''stars fell like rain'' in Chinese records of the time. The shower originates from comet 3D/Biela whose disintegration in the mid-1800's is linked to the outbursts, but the shower has been weak or absent since the late 19th century. This shower returned in 2011 December with a zenithal hourly rate of approximately 50, the strongest return in over a hundred years. Some 122 probable Andromedid orbits were detected by the Canadian Meteor Orbit Radar while one possible brighter Andromedid member was detected by the Southern Ontario Meteor Network and several single station possible Andromedids by the Canadian Automated Meteor Observatory. The shower outburst occurred during 2011 December 3-5. The radiant at R.A. +18 Degree-Sign and decl. +56 Degree-Sign is typical of the ''classical'' Andromedids of the early 1800s, whose radiant was actually in Cassiopeia. Numerical simulations of the shower were necessary to identify it with the Andromedids, as the observed radiant differs markedly from the current radiant associated with that shower. The shower's orbital elements indicate that the material involved was released before 3D/Biela's breakup prior to 1846. The observed shower in 2011 had a slow geocentric speed (V{sub G} = 16 km s{sup -1}) and was comprised of small particles: the mean measured mass from the radar is {approx}5 Multiplication-Sign 10{sup -7} kg, corresponding to radii of 0.5 mm at a bulk density of 1000 kg m{sup -3}. Numerical simulations of the parent comet indicate that the meteoroids of the 2011 return of the Andromedids shower were primarily ejected during 3D/Biela's 1649 perihelion passage. The orbital characteristics, radiant, and timing as well as the absence of large particles in the streamlet are all broadly consistent with simulations. However, simulations of the 1649 perihelion passage necessitate going

  1. An O({alpha}{sub s}) Monte Carlo for W production with parton showering

    SciTech Connect

    Baer, H.A.

    1991-12-31

    We construct an event generator for p{bar p}{yields}W{sup +}X{yields}e{sup +}{nu}X including complete O({alpha}{sub s}) corrections, and interface with initial and final state parton showers. Problems with negative weights and with double counting higher order parton radiation are averted. We present results for W+n-jet production, and compare with results from complete tree-level calculations, and shower calculations off of the lowest order 2{yields}2 sub-process. We also compute the {sub qT}(W) distribution, and compare with data.

  2. An O([alpha][sub s]) Monte Carlo for W production with parton showering

    SciTech Connect

    Baer, H.A.

    1991-01-01

    We construct an event generator for p[bar p][yields]W[sup +]X[yields]e[sup +][nu]X including complete O([alpha][sub s]) corrections, and interface with initial and final state parton showers. Problems with negative weights and with double counting higher order parton radiation are averted. We present results for W+n-jet production, and compare with results from complete tree-level calculations, and shower calculations off of the lowest order 2[yields]2 sub-process. We also compute the [sub qT](W) distribution, and compare with data.

  3. A Multi-Purpose Astronaut Shower for Long-Duration Mirogravity Missions

    NASA Astrophysics Data System (ADS)

    Bernasconi, M. C.; Versteeg, M.; Zenger, R.

    An initial study for an Advanced Kind Of Shower (AKOS) has attempted to define the need and advantages, as well as develop a concept, for an astronaut's shower. Relying on past studies, on flight experiences, and on the ensuing critiques, and building on an interdisciplinary approach, the study defined a modular piece of equipment that - using parts inspired by commercially- available products - that for the first time could satisfy different functions for the hygiene, well-being, and health support of the crew members.

  4. Containerized Self-Service Laundry and Small Unit Shower in Operation Restore Democracy

    DTIC Science & Technology

    1996-02-01

    period. Target group was the Bn’s 50 female soldiers. Since other shower facilities were available, usage by the female soldiers was erratic and data...gal water buffalo tank on 16 Nov. 50 females in the Bn were the target group . Initial usage reports were positive. The system worked well and has

  5. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  6. The homestake surface-underground scintillators: Initial results

    NASA Technical Reports Server (NTRS)

    Cherry, M. L.; Corbato, S.; Daily, T.; Fenyves, E. J.; Kieda, D.; Lande, K.; Lee, C. K.

    1986-01-01

    The first 70 tons of the 140-ton Large Area Scintillation Detector (LASD) have been operating since Jan. 1985 at a depth of 4850 ft. (4200 m.w.e.) in the Homestake Gold Mine, Lead, S.D. A total of 4 x 10(4) high-energy muons (E sub mu is approx. 2.7 TeV at the surface) have been detected. The remainder of the detector is scheduled to be in operation by the Fall of 1985. In addition, a surface air shower array is under construction. The first 27 surface counters, spaced out over an area of 270' x 500', began running in June, 1985. The LASD performance, the potential of the combined shower array and underground muon experiment for detecting point sources, and the initial results of a search for periodic emission from Cygnus X-3 are discussed.

  7. Initial Testing of a Two-Dimensional Computer Code for Microwave-Induced Surface Breakdown in Air

    DTIC Science & Technology

    1991-06-01

    operation of high- voltage electrical equipment are electron emission and surface flashover . As a step toward further understanding of these phenomena in gas...INITIAL TESTING OF A TWO-DIMENSIONAL COMPUTER CODE FOR MICROWAVE-INDUCED SURFACE BREAKDOWN IN AIR* D.J. Mayhall and J.H. Yee Lawrence Livermore...computer code for microwave-induced surface breakdown in air is developed. This code is based on finite difference approximations to Maxwell’s curl

  8. The exposure of children to deploying side air bags: an initial field assessment.

    PubMed

    Arbogast, Kristy B; Kallan, Michael J

    2007-01-01

    Tremendous effort has been invested in the laboratory to ensure side air bag (SAB) deployments minimize injury metrics in pediatric anthropometric test devices (ATDs). Little is known, however, about the experience of children exposed to this technology in real world crashes. Therefore, the objective of this study was to determine the prevalence of SAB exposure in children and provide estimates of injury risk among those exposed. This study utilized data from the Partners for Child Passenger Safety study, a large-scale child-focused crash surveillance system, to identify a probability sample of 348 child occupants, age 0-15 years, weighted to represent 6,600 children, in vehicles of model year 1998 and newer, equipped with SABs, in side impact crashes from three large U.S. regions between 1/1/05 and 12/31/06. In the study sample, 27 children per 1000 children in crashes were exposed to a deployed side air bag. Over 75% of these children were seated in the rear seat and 83% were exposed to a head curtain SAB. 65% of those exposed were less than 9 years of age. Of those exposed, 10.6% sustained an AIS2+ injury; all injuries were of the AIS 2 level and limited to the head or upper extremity. This paper provides the first population-based estimates of the exposure of children to SABs. Initial experience suggests that the risk of injury is fairly low with only one in ten sustaining injury - none of which were serious or life threatening. These findings offer assurance that efforts by regulators and the automotive industry to minimize negative consequences from SABs to vulnerable occupants appear to be effective and cause no change in the current recommendation of safe seating for children next to SABs.

  9. Body composition in air and road inductees at high altitude during the initial days of acclimatization

    NASA Astrophysics Data System (ADS)

    Ray, U. S.; Selvamurthy, W.

    This study assesses body composition changes and their time course during the initial days of acclimatization to high altitude (HA). Comparisons were made between gradual and acute induction to HA using 60 male lowlander volunteers (24-28 years of age) divided into two equal groups for inducting them to HA. Thirty subjects were air-lifted from sea level (SL) to 3500 m HA in 1 h. These subjects were air inductees (AI). The other 30 subjects were transported in 4 days by road to the same location at 3500 m. These were road inductees (RI). After remaining for 15 days at 3500 m both groups were inducted to 4200 m by road. All the subjects could not reach the various altitudes at the same time due to logistical problems. Ultimately, data for each altitude (SL, 3500 m and 4200 m) were available for only 26 RI subjects and 10 AI subjects. Skinfold thickness (SKF) measurements for the subscapular, thigh, triceps, biceps, juxtanipple, umbilicus, suprailiac and calf regions were taken in order to calculate fat percentages. Measurements were taken at SL and on days 1 and 9 at both 3500 m and 4200 m. On day 1 at 3500 m, RI showed a significant fall in body weight (BW) with respect to SL but AI maintained it. On subsequent days at HA both groups showed a significant fall in BW and lean body mass but not in percentage fat. SKF in the biceps and triceps regions decreased significantly but in the umbilicus and suprailiac regions it significantly increased at HA in both groups. Body composition, along with other parameters, is discussed determining the acclimatization schedule for sojourners at HA. Possibly, translocation of body fat takes place from the periphery to deep body fat depots in the core/main trunk due to the cold at HA.

  10. Assessing risk from dangerous meteoroids in main meteor showers

    NASA Astrophysics Data System (ADS)

    Murtazov, A.

    2015-01-01

    The risk from dangerous meteoroids in main meteor showers is calculated. The showers were: Quadrantids-2014; Eta Aquariids-2013, Perseids-2014 and Geminids-2014. The computed results for the risks during the shower periods of activity and near the maximum are provided.

  11. 40 CFR 60.4875 - By what date must I conduct the initial air pollution control device inspection and make any...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air pollution control device inspection and make any necessary repairs? 60.4875 Section 60.4875... Initial Compliance Requirements § 60.4875 By what date must I conduct the initial air pollution control device inspection and make any necessary repairs? (a) You must conduct an air pollution control...

  12. 40 CFR 60.4875 - By what date must I conduct the initial air pollution control device inspection and make any...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air pollution control device inspection and make any necessary repairs? 60.4875 Section 60.4875... Initial Compliance Requirements § 60.4875 By what date must I conduct the initial air pollution control device inspection and make any necessary repairs? (a) You must conduct an air pollution control...

  13. 40 CFR 60.4875 - By what date must I conduct the initial air pollution control device inspection and make any...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air pollution control device inspection and make any necessary repairs? 60.4875 Section 60.4875... Initial Compliance Requirements § 60.4875 By what date must I conduct the initial air pollution control device inspection and make any necessary repairs? (a) You must conduct an air pollution control...

  14. 40 CFR 60.4875 - By what date must I conduct the initial air pollution control device inspection and make any...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air pollution control device inspection and make any necessary repairs? 60.4875 Section 60.4875... Initial Compliance Requirements § 60.4875 By what date must I conduct the initial air pollution control device inspection and make any necessary repairs? (a) You must conduct an air pollution control...

  15. The new July meteor shower

    NASA Astrophysics Data System (ADS)

    Zoladek, Przemyslaw; Wisniewski, Mariusz

    2012-12-01

    A new meteor stream was found after an activity outburst observed on 2005 July 15. The radiant was located five degrees west of the possible early Perseid radiant, close to the star Zeta Cassiopeiae. Numerous bright meteors and fireballs were observed during this maximum. Analysis of the IMO Video Database and the SonotaCo orbital database revealed an annual stream which is active just before the appearance of the first Perseids, with a clearly visible maximum at solar longitude 113°1. Activity of the stream was estimated as two times higher than activity of the Alpha Capricornids at the same time. The activity period extends from July 12 to 17, during maximum the radiant is visible at coordinates alpha = 5°9, delta = +50°5, and observed meteors are fast, with Vg = 57.4 km/s. The shower was reported to the IAU Meteor Data Center and recognized as a new discovery. According to IAU nomenclature the new stream should be named the Zeta Cassiopeiids (ZCS). %z Arlt R. (1992). WGN, Journal of the IMO, 20:2, 62-69. Drummond J. D. (1981). Icarus, 45, 545-553. Kiraga M. and Olech A. (2001). In Arlt R., Triglav M., and Trayner C., editors, Proceedings of the International Meteor Conference, Pucioasa, Romania, 21-24 September 2000, pages 45-51. IMO. Molau S. (2007). In Bettonvil F. and Kac J., editors, Proceedings of the International Meteor Conference, Roden, The Netherlands, 14-17 September 2006, pages 38-55. IMO. Molau S. and Rendtel J. (2009). WGN, Journal of the IMO, 37:4, 98-121. Olech A., Zoladek P., Wisniewski M., Krasnowski M., Kwinta M., Fajfer T., Fietkiewicz K., Dorosz D., Kowalski L., Olejnik J., Mularczyk K., and Zloczewski K. (2006). In Bastiaens L., Verbert J., Wislez J.-M., and Verbeeck C., editors, Proceedings of the International Meteor Conference, Oostmalle, Belgium, 15-18 September 2005, pages 53-62. IMO. Poleski R. and Szaruga K. (2006). In Bastiaens L., Verbert J., Wislez J.-M., and Verbeeck C., editors, Proceedings of the International Meteor

  16. 49 CFR 228.321 - Showering facilities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION HOURS OF SERVICE OF RAILROAD EMPLOYEES; RECORDKEEPING AND REPORTING; SLEEPING QUARTERS Safety and Health Requirements for Camp Cars Provided by Railroads as Sleeping Quarters § 228.321 Showering facilities. (a) Number. Each individual camp car that provides sleeping facilities must contain...

  17. Systematic Improvement of QCD Parton Showers

    SciTech Connect

    Winter, Jan; Hoeche, Stefan; Hoeth, Hendrik; Krauss, Frank; Schonherr, Marek; Zapp, Korinna; Schumann, Steffen; Siegert, Frank; /Freiburg U.

    2012-05-17

    In this contribution, we will give a brief overview of the progress that has been achieved in the field of combining matrix elements and parton showers. We exemplify this by focusing on the case of electron-positron collisions and by reporting on recent developments as accomplished within the SHERPA event generation framework.

  18. Summing threshold logs in a parton shower

    NASA Astrophysics Data System (ADS)

    Nagy, Zoltán; Soper, Davison E.

    2016-10-01

    When parton distributions are falling steeply as the momentum fractions of the partons increases, there are effects that occur at each order in α s that combine to affect hard scattering cross sections and need to be summed. We show how to accomplish this in a leading approximation in the context of a parton shower Monte Carlo event generator.

  19. Is there any association between imidapril hydrochloride stability profile under dry air conditions and cancer initiation?

    PubMed

    Regulska, Katarzyna; Murias, Marek; Stanisz, Beata; Regulski, Miłosz

    2013-11-18

    Stability study for imidapril hydrochloride (IMD) was performed under stress conditions of increased temperature (T=373 K) and decreased relative air humidity (RH=0%) in order to obtain and identify its degradation product. The degradation sample stored for 15 days under the above environmental conditions was analyzed by LC-MS technique and it was found that the only degradation impurity formed in the course of the investigated drug degradation was IMD diketopiperazine derivative (DKP) which was produced by dehydration and intramolecular cyclization. The kinetics of its formation was analyzed by a revalidated RP-HPLC method and the kinetic model of this reaction was established. It was concluded that the DKP formation follows Prout-Tompkins kinetics with the rate constant k±Δk=2.034±0.157×10(-6) [s(-1)]. The obtained degradation impurity was further assessed with respect to its mutagenic potential using commercial Ames MPF 98/100 microplate format mutagenicity assay kit equipped with Salmonella typhimurium strains TA 98 and TA 100. Both strains were exposed to six concentrations (in a range of 0.16-5.0mg/mL) of DKP in the presence and absence of metabolic activation system. No mutagenic effect was observed confirming that the presence of DKP in IMD final dosage form has no impact on cancer initiation.

  20. Effects of initial air removal methods on microorganisms and characteristics of fermented plant beverages.

    PubMed

    Kantachote, Duangporn; Charernjiratrakul, Wilawan

    2008-01-15

    The effects of 3 different methods for removing the initial air on the properties of fermented plant beverages produced from phom-nang seaweed (Gracilaria fisheri) and wild forest noni (Morinda coreia Ham.) were investigated. Only method M which covered the space above the fermentation liquid with a water filled plastic bag produced no surface film of yeast, had the highest acidity and also antibacterial activity from both plants after 90 days of fermentation. However, the yeast count still exceeded the standard guidelines for plant beverages. The fermented beverage from wild forest noni showed more antibacterial activity against 3 of 4 pathogenic bacteria tested than that from the phomnang seaweed, probably for its higher levels of acidity and ethanol content. Lactic Acid Bacteria (LAB) isolated from the fermentation samples from days 1-5 using the method M from both fermented plant beverages were Leuconostoc mesenteroides supsp. mesenteroides and Leu. mesenteroides subsp. dextranicum while presence of Lactobacilus plantarum was only recorded at days 4-5 in the wild forest noni beverage. From days 6-14 the isolates were Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus brevis from wild forest noni beverage, whereas only L. brevis was not detected in the seaweed beverage. During days 21-45 both beverages had a similar LAB population of L. plantarum and L. brevis while L. coryniformis was only found in the wild forest noni beverage. Between days 60-90 in both plant beverages only L. plantarum and Lactobacillius sp. were detected.

  1. The Effect of Air Density on Atmospheric Electric Fields Required for Lightning Initiation from a Long Airborne Object

    NASA Technical Reports Server (NTRS)

    Bazelyan, E. M.; Aleksandrov, N. L.; Raizer, Yu. Pl.; Konchankov, A. M.

    2006-01-01

    The purpose of the work was to determine minimum atmospheric electric fields required for lightning initiation from an airborne vehicle at various altitudes up to 10 km. The problem was reduced to the determination of a condition for initiation of a viable positive leader from a conductive object in an ambient electric field. It was shown that, depending on air density and shape and dimensions of the object, critical atmospheric fields are governed by the condition for leader viability or that for corona onset. To establish quantitative criteria for reduced air densities, available observations of spark discharges in long laboratory gaps were analyzed, the effect of air density on leader velocity was discussed and evolution in time of the properties of plasma in the leader channel was numerically simulated. The results obtained were used to evaluate the effect of pressure on the quantitative relationships between the potential difference near the leader tip, leader current and its velocity; based on these relationships, criteria for steady development of a leader were determined for various air pressures. Atmospheric electric fields required for lightning initiation from rods and ellipsoidal objects of various dimensions were calculated at different air densities. It was shown that there is no simple way to extend critical ambient fields obtained for some given objects and pressures to other objects and pressures.

  2. The formation of ignition centers before the front of spherical flame in hydrogen-air mixtures under intense initiation

    NASA Astrophysics Data System (ADS)

    Petukhov, V. A.; Bublik, N. P.; Gusev, P. A.; Gutkin, L. D.; Solntsev, O. I.

    2016-11-01

    Studied is the influence of volume of hydrogen-air mixture, its composition and energy of its initiation on the formation of ignition centers before the front of spherical flame. During the experiments the mixture was placed into thin rubber envelopes of spherical shape having the initial volume of 7 and 40 m3. The mixture was initiated in the center of the reaction volume by the energy which was several times less than the critical energy of direct initiation of detonation. With increasing the initial volume of the mixture with the identical composition, registered is a decrease of the initiation energy at which the ignition centers before the front of spherical flame are formed.

  3. Lunar Impact Detections During the 2010 Geminid Meteor Shower

    NASA Technical Reports Server (NTRS)

    Suggs, Ron; Suggs, Rob; Moser, Danielle; Blaauw, Rhiannon

    2011-01-01

    Lunar video observations are routinely conducted at the NASA Marshall Space Flight Center in Huntsville Alabama for the detection of meteoroid impacts. Over 240 impacts have been detected since the start of the observing program initiated approximately 5 years ago. During this time it has been fairly rare that lunar observing conditions and the weather have been favorable during the peak of the major showers. However, observing conditions were marginally favorable during the peak of the 2010 Geminids. On Dec. 14, 2010 approximately 5.5 hours of video were recorded. Even though the lunar phase was just outside the constraints established for optimum lunar impact monitoring, the resulting video was of sufficient quality that 21 lunar impacts were detected yielding an average impact rate of approximately 4 per hour. This compares to 17 lunar impacts detected over 40 nights of observations ( approximately 100 hours of lunar video) yielding an average impact rate of 1 per 6 hours for the whole of 2010, excluding Dec. 14. The results of the 2010 Geminid lunar impact detections will be discussed along with previous results from the 2006 Geminid shower that also coincided within the lunar observing window.

  4. Ground detectors for the study of cosmic ray showers

    NASA Astrophysics Data System (ADS)

    Salazar, H.; Villasenor, L.

    2008-06-01

    We describe the work that we have done over the last decade to design and construct instruments to measure properties of cosmic rays in Mexico. We describe the detection of decaying and crossing muons in a water Cherenkov detector and discuss an application of these results to calibrate water Cherenkov detectors. We also describe a technique to separate isolated isolated muons and electrons in water Cherenkov detector. Next we describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla (19°N, 90°W, 800 g/cm2) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1 PeV.

  5. The Nevada Rural Ozone Initiative (NVROI): Insights to understanding air pollution in complex terrain.

    PubMed

    Gustin, Mae Sexauer; Fine, Rebekka; Miller, Matthieu; Jaffe, Dan; Burley, Joel

    2015-10-15

    The Nevada Rural Ozone Initiative (NVROI) was established to better understand O3 concentrations in the Western United States (US). The major working hypothesis for development of the sampling network was that the sources of O3 to Nevada are regional and global. Within the framework of this overarching hypothesis, we specifically address two conceptual meteorological hypotheses: (1) The high elevation, complex terrain, and deep convective mixing that characterize Nevada, make this state ideally located to intercept polluted parcels of air transported into the US from the free troposphere; and (2) site specific terrain features will influence O3 concentrations observed at surface sites. Here, the impact of complex terrain and site location on observations are discussed. Data collected in Nevada at 6 sites (1385 to 2082 m above sea level (asl)) are compared with that collected at high elevation sites in Yosemite National Park and the White Mountains, California. Average daily maximum 1-hour concentrations of O3 during the first year of the NVROI ranged from 58 to 69 ppbv (spring), 53 to 62 ppbv (summer), 44 to 49 ppbv (fall), and 37 to 45 ppbv (winter). These were similar to those measured at 3 sites in Yosemite National Park (2022 to 3031 m asl), and at 4 sites in the White Mountains (1237 to 4342 m asl) (58 to 67 ppbv (summer) and 47 to 58 ppbv (fall)). Results show, that in complex terrain, collection of data should occur at high and low elevation sites to capture surface impacts, and site location with respect to topography should be considered. Additionally, concentrations measured are above the threshold reported for causing a reduction in growth and visible injury for plants (40 ppbv), and sustained exposure at high elevation locations in the Western USA may be detrimental for ecosystems.

  6. Airborne measurements of air pollution chemistry and transport. 1: Initial survey of major air basins in California

    NASA Technical Reports Server (NTRS)

    Gloria, H. R.; Pitts, J. N., Jr.; Behar, J. V.; Bradburn, G. A.; Reinisch, R. F.; Zafonte, L.

    1972-01-01

    An instrumented aircraft has been used to study photochemical air pollution in the State of California. Simultaneous measurements of the most important chemical constituents (ozone, total oxidant, hydrocarbons, and nitrogen oxides, as well as several meteorological variables) were made. State-of-the-art measurement techniques and sampling procedures are discussed. Data from flights over the South Coast Air Basin, the San Francisco Bay Area, the San Joaquin Valley, the Santa Clara and Salinas Valleys, and the Pacific Ocean within 200 miles of the California coast are presented. Pollutants were found to be concentrated in distant layers up to at least 18,000 feet. In many of these layers, the pollutant concentrations were much higher than at ground level. These findings bring into serious question the validity of the present practice of depending solely on data from ground-based monitoring stations for predictive models.

  7. Artificial Neural Network as the FPGA Trigger in the Cyclone V based Front-End for a Detection of Neutrino-Origin Showers

    SciTech Connect

    Szadkowski, Zbigniew; Glas, Dariusz; Pytel, Krzysztof

    2015-07-01

    Neutrinos play a fundamental role in the understanding of the origin of ultra-high-energy cosmic rays. They interact through charged and neutral currents in the atmosphere generating extensive air showers. However, their a very low rate of events potentially generated by neutrinos is a significant challenge for a detection technique and requires both sophisticated algorithms and high-resolution hardware. A trigger based on a artificial neural network was implemented into the Cyclone{sup R} V E FPGA 5CEFA9F31I7 - the heart of the prototype Front-End boards developed for tests of new algorithms in the Pierre Auger surface detectors. Showers for muon and tau neutrino initiating particles on various altitudes, angles and energies were simulated in CORSICA and Offline platforms giving pattern of ADC traces in Auger water Cherenkov detectors. The 3-layer 12-8-1 neural network was taught in MATLAB by simulated ADC traces according the Levenberg-Marquardt algorithm. Results show that a probability of a ADC traces generation is very low due to a small neutrino cross-section. Nevertheless, ADC traces, if occur, for 1-10 EeV showers are relatively short and can be analyzed by 16-point input algorithm. We optimized the coefficients from MATLAB to get a maximal range of potentially registered events and for fixed-point FPGA processing to minimize calculation errors. New sophisticated triggers implemented in Cyclone{sup R} V E FPGAs with large amount of DSP blocks, embedded memory running with 120 - 160 MHz sampling may support a discovery of neutrino events in the Pierre Auger Observatory. (authors)

  8. A Simple shower and matching algorithm

    SciTech Connect

    Giele, Walter T.; Kosower, David A.; Skands, Peter Z.; /Fermilab

    2007-07-01

    We present a simple formalism for parton-shower Markov chains. As a first step towards more complete 'uncertainty bands', we incorporate a comprehensive exploration of the ambiguities inherent in such calculations. To reduce this uncertainty, we then introduce a matching formalism which allows a generated event sample to simultaneously reproduce any infrared safe distribution calculated at leading or next-to-leading order in perturbation theory, up to sub-leading corrections. To enable a more universal definition of perturbative calculations, we also propose a more general definition of the hadronization cutoff. Finally, we present an implementation of some of these ideas for final-state gluon showers, in a code dubbed VINCIA.

  9. The midpoint between dipole and parton showers

    SciTech Connect

    Höche, Stefan; Prestel, Stefan

    2015-09-28

    We present a new parton-shower algorithm. Borrowing from the basic ideas of dipole cascades, the evolution variable is judiciously chosen as the transverse momentum in the soft limit. This leads to a very simple analytic structure of the evolution. A weighting algorithm is implemented that allows one to consistently treat potentially negative values of the splitting functions and the parton distributions. Thus, we provide two independent, publicly available implementations for the two event generators PYTHIA and SHERPA.

  10. Radar observations of the Volantids meteor shower

    NASA Astrophysics Data System (ADS)

    Younger, J.; Reid, I.; Murphy, D.

    2016-01-01

    A new meteor shower occurring for the first time on 31 December 2015 in the constellation Volans was identified by the CAMS meteor video network in New Zealand. Data from two VHF meteor radars located in Australia and Antarctica have been analyzed using the great circle method to search for Volantids activity. The new shower was found to be active for at least three days over the period 31 December 2015 - 2 January 2016, peaking at an apparent radiant of R.A. = 119.3 ± 3.7, dec. = -74.5 ± 1.9 on January 1st. Measurements of meteoroid velocity were made using the Fresnel transform technique, yielding a geocentric shower velocity of 28.1 ± 1.8 km s-1. The orbital parameters for the parent stream are estimated to be a = 2.11 AU, e = 0.568, i = 47.2°, with a perihelion distance of q = 0.970 AU.

  11. Combat Support Execution Planning and Control. An Assessment of Initial Implementations in Air Force Exercises

    DTIC Science & Technology

    2009-01-01

    time-phased force and deployment data USAFE U.S. Air Forces in Europe UTASC USAFE Theater Aerospace Support Center UTC unit type code WPC Warfighter...scenario and supporting simulated environment were developed and run by the Warfighter Preparation Center ( WPC ) facility at Einsedlerhof Air Station near...participate.11 Forces below the operational level were simulated by the WPC . The training audience consisted of the JFACC and staff, AFFOR staff, AOC, and the

  12. Combat Support Execution Planning and Control: An Assessment of Initial Implementations in Air Force Exercises

    DTIC Science & Technology

    2009-01-01

    Forces in Europe UTASC USAFE Theater Aerospace Support Center UTC unit type code WPC Warfighter Preparation Center XML Extensible Markup Language 1...developed and run by the Warfighter Preparation Center ( WPC ) facility at Einsedlerhof Air Station near Ramstein Air Base (AB), Germany, which is jointly...simulated by the WPC . The training audience consisted of the JFACC and staff, AFFOR staff, AOC, and the AFEUR.12 Because of this level of participa- tion

  13. Funding Cyberspace: The Case for an Air Force Venture Capital Initiative

    DTIC Science & Technology

    2013-08-01

    Additionally, an Air Force– branded VCI would likely attract additional private capital for technological advancement. The service can in fact innovate...previously caught in the valley between basic R&D funding and an acquisition program of record. Recognition of the Air Force brand , combined with VC business...Innovation,” Intel Corporation, accessed 4 April 2013, http:// www.intel.com/content/www/us/en/history/ museum -gordon-moore-law.html. 3. Capt Michael E

  14. Letter Report Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Pahranagat National Wildlife Refuge, Lincoln County, Nevada

    SciTech Connect

    J. Engelbrecht; I. Kavouras; D. Campbell; S. Campbell; S. Kohl; D. Shafer

    2009-04-02

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Pahranagat NWR, Beatty, Rachel, Caliente, Crater Flat, and Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data on completion of the site's sampling program.

  15. Letter Report: Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Pahranagat National Wildlife Refuge, Lincoln County, Nevada

    SciTech Connect

    J. Englebrecht; I. Kavouras; D. Campbell; S. Campbell; S. Kohl; D. Shafer

    2008-08-01

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Pahranagat NWR, Beatty, Rachel, Caliente, Crater Flat, and Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data on completion of the site's sampling program.

  16. Letter Report Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Tonopah Airport, Nye County, Nevada

    SciTech Connect

    J. Engelbrecht; I. Kavouras; D. Campbell; S. Campbell; S. Kohl; D. Shafer

    2009-04-02

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Tonopah Airport, Beatty, Rachel, Caliente, Pahranagat NWR, Crater Flat, and the Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data, on completion of the site's sampling program.

  17. Letter Report: Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Crater Flat, Nye County, Nevada

    SciTech Connect

    J. Engelbrecht; I. Kavouras; D. Campbell; S. Campbell; S. Kohl; D. Shafer

    2008-08-01

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) (cover page figure) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Beatty, Sarcobatus Flats, Rachel, Caliente, Pahranagat NWR, Crater Flat, and Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data, on completion of the site's sampling program.

  18. Letter Report Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Crater Flat, Nye County, Nevada

    SciTech Connect

    J. Engelbrecht; I. Kavouras; D. Campbell; S.Campbell; S. Kohl; D. Shafer

    2009-04-02

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) (cover page figure) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Beatty, Sarcobatus Flats, Rachel, Caliente, Pahranagat NWR, Crater Flat, and Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data, on completion of the site's sampling program.

  19. Letter Report: Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Caliente, Lincoln County, Nevada

    SciTech Connect

    J. Englebrecht; I. Kavouras; D. Campbell; S. Campbell; S. Kohl; D. Shafer

    2008-08-01

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Beatty, Sarcobatus Flats, Rachel, Caliente, Pahranagat NWR, Crater Flat, and Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data, on completion of the site's sampling program.

  20. Letter Report: Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Tonopah Airport, Nye County, Nevada

    SciTech Connect

    J. Engelbrecht; I. Kavouras; D Campbell; S. Campbell; S. Kohl, D. Shafer

    2008-08-01

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Tonopah Airport, Beatty, Rachel, Caliente, Pahranagat NWR, Crater Flat, and the Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data, on completion of the site's sampling program.

  1. Biodrying of sewage sludge: kinetics of volatile solids degradation under different initial moisture contents and air-flow rates.

    PubMed

    Villegas, Manuel; Huiliñir, Cesar

    2014-12-01

    This study focuses on the kinetics of the biodegradation of volatile solids (VS) of sewage sludge for biodrying under different initial moisture contents (Mc) and air-flow rates (AFR). For the study, a 3(2) factorial design, whose factors were AFR (1, 2 or 3L/minkgTS) and initial Mc (59%, 68% and 78% w.b.), was used. Using seven kinetic models and a nonlinear regression method, kinetic parameters were estimated and the models were analyzed with two statistical indicators. Initial Mc of around 68% increases the temperature matrix and VS consumption, with higher moisture removal at lower initial Mc values. Lower AFRs gave higher matrix temperatures and VS consumption, while higher AFRs increased water removal. The kinetic models proposed successfully simulate VS biodegradation, with root mean square error (RMSE) between 0.007929 and 0.02744, and they can be used as a tool for satisfactory prediction of VS in biodrying.

  2. How to estimate the effect of an intense meteor shower on human space activities

    NASA Astrophysics Data System (ADS)

    Wu, Guangjie

    2009-08-01

    In the present age, the potential threat to space projects coming from some intense meteor storms has been noticed. Especially, the increasing activities of mankind in space for scientific, commercial and military purposes have led to an increase in safety-related problems about the satellites, space stations and astronauts. Several new techniques for observing meteors and meteor showers have been developed. However, how to estimate even predict the effect of an intense meteor shower should be further studied. The initial definition about a meteor storm based on visual observations with a Zenithal Hourly Rate of over one thousand seems insufficient, since it only means a storm or burst of meteors in numbers. In 2006 the author suggested a synthetical index of the potential threats about intense activities of meteors; however, it is too complex to determine several parameters. In this paper, the author suggests a Special True Number Flux Density ( STNFD). Set a certain energy-limit, or a certain electric-charge-limit, and then calculate the number flux density. Through the comparison between two of the 10 strong meteor showers in recent years it is found that the important factor affecting the space flight security is not only the number of meteoroids, but also their velocities, their average energy and the population index r. Calculations show that Giacobinids, even June Bootids, should be one of the most hazardous meteor showers.

  3. High speed cinematography of the initial break-point of latex condoms during the air burst test.

    PubMed

    Stube, R; Voeller, B; Davidhazy, A

    1990-06-01

    High speed cinematography of latex condoms inflated to burst under standard (ISO) conditions reveals that rupture of the condom typically is initiated at a small focal point on the shank of the condom and then rapidly propagates throughout the condom's surface, often ending with partial or full severance of the condom at its point of attachment to the air burst instrument. This sequence of events is the reverse of that sometimes hypothesized to occur, where initiation of burst was considered to begin at the attachment point and to constitute a testing method artifact. This hypothesis of breakage at the attachment point, if true, would diminish the value of the air burst test as a standard for assessing manufacturing quality control as well as for condom strength measurements and comparisons.

  4. An Evaluation of the Accuracy of Meteor Shower Forecasts

    NASA Technical Reports Server (NTRS)

    Cooke, W.; Moser, D.

    2004-01-01

    Brought into being by the recent Leonid meteor storms, meteor shower forecasts are now regarded by many spacecraft projects as necessary inputs into the planning of spacecraft operations. We compare the shower forecasts made by various researchers over the past six years to actual shower observations in an attempt to create an overall picture of forecast accuracy, specifically focusing on the three aspects most important to space vehicles: 1) the time of shower maximum, 2) the half-width (duration), and 3) the maximum Zenith Hourly Rate (ZHR). It will be noted that, while the times of maxima are generally predicted to within several minutes, the peak ZHRs are often overestimated and shower half-widths are frequently not even calculated. The difficulties involved in converting shower ZHRs into the meteoroid fluxes needed to assess spacecraft risk are also discussed.

  5. FAA Air Traffic Control Operations Concepts. Volume 3. ISSS (Initial Sector Suite System) En Route Controllers. Change 1

    DTIC Science & Technology

    1988-07-29

    series of ope-rations concepts for the FAA’s Advanced Automation System (AAS). It describes how en route controllers in Air Route Traffic Control Center...facilities may perform their operational jobs in the Initial Stector Suite System (ISSS) enviroinment- ISSS functionality is assumed to be as described...in the AAS System Level Specification, 28 August 1987. Included here are: Composition Graphs, showing the logizal flow of operational tasks performed

  6. Mexico City air quality research initiative, volume 3, modeling and simulation

    SciTech Connect

    Mauzy, A.

    1994-06-01

    The objective of the modeling and simulation task was to develop, test, and apply an appropriate set of models that could translate emission changes into air quality changes. Specifically, we wanted to develop models that could describe how existing measurements of ozone (O{sub 3}), carbon monoxide (CO), and sulfur dioxide (SO{sub 2}) would be expected to change if their emissions were changed. The modeling must be able to address the effects of difference in weather conditions and changes in land use as well as the effects of changes in emission levels. It must also be able to address the effects of changes in the nature and distribution of the emissions as well as changes in the total emissions. A second objective was to provide an understanding of the conditions that lead to poor air quality in Mexico City. We know in a general sense that Mexico City`s poor air quality is the result of large quantities of emissions in a confined area that is subject to light winds, but we did not know much about many aspects of the problem. For example, is the air quality on a given day primarily the result of emissions on that day...or is there an important carryover from previous nights and days? With a good understanding of the important meteorological circumstances that lead to poor air quality, we learn what it take duce an accurate forecast of impending quality so that we can determine the advisability of emergency measures.

  7. Glossary of AWS Acrinabs. Acronyms, Initialisms, and Abbreviations Commonly Used in Air Weather Service

    DTIC Science & Technology

    1991-01-01

    National Environmental Data Referral Service NASNET. ... National Airspace System Network NEDS ......... Navy Environmenta! Display Station NASP...Electrical Manufacturers Association NASS ......... National Agricultural Statistics Service NEMS ........ Nimbus-E Microwave Spectrometer NATO...North Atlantic Treaty Organization NEO ........... noncombatant emergency operations NATS ......... Naval Air Transport Service NEPA --------- National

  8. Mexico City air quality research initiative. Volume 2, Problem definition, background, and summary of prior research

    SciTech Connect

    Not Available

    1994-06-01

    Air pollution in Mexico City has increased along with the growth of the city, the movement of its population, and the growth of employment created by industry. The main cause of pollution in the city is energy consumption. Therefore, it is necessary to take into account the city`s economic development and its prospects when considering the technological relationships between well-being and energy consumption. Air pollution in the city from dust and other particles suspended in the air is an old problem. However, pollution as we know it today began about 50 years ago with the growth of industry, transportation, and population. The level of well-being attained in Mexico City implies a high energy use that necessarily affects the valley`s natural air quality. However, the pollution has grown so fast that the City must act urgently on three fronts: first, following a comprehensive strategy, transform the economic foundation of the city with nonpolluting activities to replace the old industries, second, halt pollution growth through the development of better technologies; and third, use better fuels, emission controls, and protection of wooded areas.

  9. Direct Initiation of Detonation in Unconfined Ethylene-Air Mixtures - Influence of Bag Size,

    DTIC Science & Technology

    1982-12-01

    preparation for...recording the time of ignition (det zero) on magnetic tape as a reference. The desired gas mixture was prepared by continuous flow of regulated quantities...constant velocity within 3% of the theoretical C-J velocity (Vcj) were observed in all ehtylene -air mixtures near stoichiometric composition (6.54%

  10. United States Air Force Research Initiation Program. 1984 Research Reports. Volume 1.

    DTIC Science & Technology

    1986-05-01

    STUDY OF TWO-STAGE LIGHT GAS GUN...8217,’ , ’,’’,,,- _-,. %,’_,’_’_,’ _,"-, ..--. ,’. ’ ,’.. .. w",r..- ... , -,., ... , ,-o. ,.-,.........,,., .....- .. ,... .. ,_.:..., . w ,.,_- PREFACE The work presented in this...Education and the United States Air Force. ’ .% . Professor R. W. Courter and his graduate student, Raymond M. Patin, worked with members of the

  11. Novel prescribed performance neural control of a flexible air-breathing hypersonic vehicle with unknown initial errors.

    PubMed

    Bu, Xiangwei; Wu, Xiaoyan; Zhu, Fujing; Huang, Jiaqi; Ma, Zhen; Zhang, Rui

    2015-11-01

    A novel prescribed performance neural controller with unknown initial errors is addressed for the longitudinal dynamic model of a flexible air-breathing hypersonic vehicle (FAHV) subject to parametric uncertainties. Different from traditional prescribed performance control (PPC) requiring that the initial errors have to be known accurately, this paper investigates the tracking control without accurate initial errors via exploiting a new performance function. A combined neural back-stepping and minimal learning parameter (MLP) technology is employed for exploring a prescribed performance controller that provides robust tracking of velocity and altitude reference trajectories. The highlight is that the transient performance of velocity and altitude tracking errors is satisfactory and the computational load of neural approximation is low. Finally, numerical simulation results from a nonlinear FAHV model demonstrate the efficacy of the proposed strategy.

  12. The Sigma-Capricornids fireball shower

    NASA Astrophysics Data System (ADS)

    Kokhirova, G.; Babadzhanov, P.; Khamroev, U.

    2014-07-01

    During 2010-2011 three fireballs belonging to the σ-Capricornids (00179 SCA) meteor shower were photographed by the Tajikistan fireball network. As a result of astrometric and photometric reductions of the obtained images, the atmospheric trajectories, radiants, velocities, orbits, and lightcurves of the fireballs, as well as the photometric masses of meteoroids produced these fireballs were determined. Taking into account the observations of six fireballs of this shower by the Prairie network (USA) (McCrosky et al. 1978) and the MORP (Canada) (Halliday et al. 1996), the period of the σ-Capricornids activity 5-24 July was determined as well as, the mean daily radiant drift was found to be Δα=0.6° for the right ascension and Δδ=0.3° for the declination. The coordinates of mean radiant are equal to α=300.4° and δ=-12.4° at the Solar longitude L=115.6°, which corresponds to 18 July. Further to the empirical PE criterion (Ceplecha, McCrosky 1976), the mean value of bulk density of the majority of fireball producing meteoroids is 0.4 g cm^{-3} that corresponds to bodies of cometary nature. This is supported also by the lightcurves of the fireballs detected in Tajikistan as well as by the fireballs' height scales that are typical for the cometary meteoroids. Two PN fireballs were classified as I and II types, and were produced, probably, by a stone meteoroid and carbonaceous chondrite, respectively. As a rule, the meteoroids of these types have an asteroidal origin. Since the cometary source of the σ-Capricornids fireballs does not cause doubts, the presence of all types among them suggests a non-homogeneous compound of the comet-progenitor of the σ-Capricornids shower.

  13. The history of meteors and meteor showers

    NASA Astrophysics Data System (ADS)

    Hughes, David W.

    The history of meteors and meteor showers can effectively start with the work of Edmond Halley who overcome the Aristotelean view of meteors as being an upper atmospheric phenomenon and introduced their extraterrestrial nature. Halley also estimated their height and velocity. The observations of the Leonids in 1799, 1833 and 1866 established meteoroids as cometary debris. Two red herrings were caught — fixed radiants and hyperbolic velocities. But the 1890 to 1950 period with two-station meteor photography, meteor spectroscopy and the radar detection of meteors saw the subject well established.

  14. The 2014 May Camelopardalid Meteor Shower

    NASA Technical Reports Server (NTRS)

    Cooke, Bill; Moser, Danielle

    2014-01-01

    On May 24, 2014 Earth will encounter multiple streams of debris laid down by Comet 209P LINEAR. This will likely produce a new meteor shower, never before seen. Rates predicted to be from 100 to 1000 meteors per hour between 2 and 4 AM EDT, so we are dealing with a meteor outburst, potentially a storm. Peak rate of 200 per hour best current estimate. Difficult to calibrate models due to lack of past observations. Models indicate mm size particles in stream, so potential risk to Earth orbiting spacecraft.

  15. Initial Development of Composite Repair Resins With Low Hazardous Air Pollutant Contents

    DTIC Science & Technology

    2008-12-01

    giving the proper viscosity and consistency for repair applications. Benzoyl peroxide is typically used as the initiator in repair resin putties...resin (component A) and acts as a promoter to break down the benzoyl peroxide and allow for free radical polymerization at room temperature. N,N...Aldrich) was added to the part A formulation because this chemical promotes free radical cure of benzoyl peroxide initiators, which are typically used

  16. United States Air Force Research Initiation Program for 1988. Volume 1

    DTIC Science & Technology

    1990-04-01

    D. R., and Golovin , M. N., "Enhanced Energy Coupling Phenomena: A State-of-the-Art Survey and Assessment," Air Force Armament Laboratory, Eglin AFB...PPM) (PPM) (PPM) 1-6 9380 8755 625 625 100% 2-1 3000 200 2800 5700 49% 2-6 3090 270 2820 7350 38% 2-11 1940 370 1570 6940 23% 1-10 2830 1250 1580 6020

  17. Environmental Assessment for the Military Housing Privatization Initiative (MHPI) Malmstrom Air Force Base, Montana

    DTIC Science & Technology

    2009-08-01

    type and amount of pollutants emitted into the atmosphere, the size and topography of the air basin , and the prevailing meteorological conditions...Upper Missouri Dearborn Rivers Sub- Basin , Sub-Unit 686 (BAH, 2008). 3.2.1.2 Surface Water MAFB lies on a plateau roughly 10 square miles in...Rivers Sub- Basin (Hydrologic Unit Code 10030102) (BAH, 2008). The watershed drainage area is approximately 6,930 acres, of which approximately 3,052

  18. United States Air Force Research Initiation Program for 1987. Volume 1

    DTIC Science & Technology

    1989-04-01

    Measurement of Electron Excitation Cross Sections of Atoms and Molecules in the Near Infrared 760-7MG-074 Rome Air Development Center 38 Superconductor...image metrics; continue to sur- vey the literature. 3. Investigate in depth surface complexity measures of differential geometry and algebraic topology...proposals was made by the contractor. Evaluation criteria consisted of: 1. Technical Excellence of the proposal 2. Continuation of the SFRP effort 3. -Cost

  19. Aluminum-Air Power Cell: the M4-cell assembly and initial tests

    SciTech Connect

    Maimoni, A.; Muelder, S.A.; Hui, W.C.

    1985-10-03

    We fabricated, assembled, and tested the modular, wedge-shaped M4 Aluminum-Air Power Cell in a system with a fluidized-bed crystallizer and hydrocyclone separator. Two M4-cell experiments validated the design premises and indicated predictable performance. The combined duration of the M4-1 and M4-2 experiments was almost 9 h. Conductive epoxy bonds are inadequate for bonding the air-cathode metal screen to current collectors; soldered joints using low melting (93/sup 0/C) Indium solder performed satisfactorily. Both experiments were terminated because of problems directly traceable to metallic tin deposited by the stannate corrosion inhibitor. Apart from problems caused by metallic tin, the M4-2 test system performed very satisfactorily. Individual cell pods are readily assembled into single or multicell stacks; it is easy to disassemble the cells after a run to determine cell condition. Air-cathode assembly is the most cumbersome aspect of the M4 cell. We obtained valuable information regarding the evolution of particle-size distribution. We did not observe substantial agglomeration of the smaller crystals. A simple model of secondary nucleation gave a reasonably good fit to the secondary nucleation observed in the M3-3 experiment.

  20. Measure Guideline. Water Management at Tub and Shower Assemblies

    SciTech Connect

    Dickson, Bruce

    2011-12-01

    Due to the high concentrations of water and the consequential risk of water damage to the home’s structure a comprehensive water management system is imperative to protect the building assemblies underlying the finish surround of tub and shower areas. This guide shows how to install fundamental waterproofing strategies to prevent water related issues at shower and tub areas.

  1. Meteor Showers of the Earth-crossing Asteroids

    NASA Astrophysics Data System (ADS)

    Pulat, Babadzhanov; Gulchekhra, Kokhirova

    2015-03-01

    The results of search for meteor showers associated with the asteroids crossing the Earthfs orbit and moving on comet-like orbits are given. It was shown that among 2872 asteroids discovered till 1.01.2005 and belonging to the Apollo and Amor groups, 130 asteroids have associated meteor showers and, therefore, are the extinct cometary nuclei.

  2. On sampling fractions and electron shower shapes

    SciTech Connect

    Peryshkin, Alexander; Raja, Rajendran; /Fermilab

    2011-12-01

    We study the usage of various definitions of sampling fractions in understanding electron shower shapes in a sampling multilayer electromagnetic calorimeter. We show that the sampling fractions obtained by the conventional definition (I) of (average observed energy in layer)/(average deposited energy in layer) will not give the best energy resolution for the calorimeter. The reason for this is shown to be the presence of layer by layer correlations in an electromagnetic shower. The best resolution is obtained by minimizing the deviation from the total input energy using a least squares algorithm. The 'sampling fractions' obtained by this method (II) are shown to give the best resolution for overall energy. We further show that the method (II) sampling fractions are obtained by summing the columns of a non-local {lambda} tensor that incorporates the correlations. We establish that the sampling fractions (II) cannot be used to predict the layer by layer energies and that one needs to employ the full {lambda} tensor for this purpose. This effect is again a result of the correlations.

  3. Optical fluxes and meteor properties of the camelopardalid meteor shower

    NASA Astrophysics Data System (ADS)

    Campbell-Brown, M. D.; Blaauw, R.; Kingery, A.

    2016-10-01

    Observations of the Camelopardalid meteor shower in May 2014 were obtained with six different sets of cameras, with limiting meteor magnitudes varying from -2M to +7M. Shower fluxes were calculated for each of the systems, from which the mass index of the shower was found to be 2.17 ± 0.04. Faint meteors in the shower were found to be stronger than average, ablating at lower altitudes than meteors at the same speed recorded with the same system, while the brightest meteors had higher ablation heights and were therefore weaker than typical meteors. These findings can be explained if large Camelopardalids are weak agglomerations of more refractory grains, which are easily disrupted in space and keep the shower supplied with small material and depleted in large material.

  4. Mexico City air quality research initiative. Volume IV. Characterization and measurement

    SciTech Connect

    Mauzy, A.

    1994-04-01

    This volume describes the methods and the data gathered in an attempt to measure and characterize the meteorological factors and the concentration of different pollutants in the Mexico City Metropolitan Area. The main objective of this document was to provide input for the simulation models and to obtain information that could be used to test and improve the models` performance. Four field campaigns were conducted, as well as routine monitoring, in order to obtain a database of atmospheric dynamics and air pollution characteristics. Sections include Airborne measurements, Remote sensing measurements, and Traditional (in situ) measurements.

  5. An Assessment of the Air Force Weather Agency’s Readiness for Knowledge Management Initiatives

    DTIC Science & Technology

    2009-03-01

    within the context of this paper. KM initiatives are typically organizational endeavors that seek to leverage the value of knowledge as an intangible ... asset (Liebowitz & Megbolugbe, 1998). “Such projects are attempts to do something useful with knowledge, to accomplish organizational objectives

  6. Estimating the Benefits of the Air Force Purchasing and Supply Chain Management Initiative

    DTIC Science & Technology

    2008-01-01

    challenge by developing an econometric model to account for such “co-occurring” factors. This monograph describes the resulting method and...Applying an Econometric Model to Estimate the Benefits of PSCM Initiatives...15 Applying the Econometric Model for NIIN-Level Outcomes

  7. Sensitivity study of (10,100) GeV gamma-ray bursts with double shower front events from ARGO-YBJ

    NASA Astrophysics Data System (ADS)

    Zhou, Xun-Xiu; Gao, Lan-Lan; Zhang, Yu; Guo, Yi-Qing; Zhu, Qing-Qi; Jia, Huan-Yu; Huang, Dai-Hui

    2016-07-01

    ARGO-YBJ, located at the Yangbajing Cosmic Ray Observatory (4300 m a.s.l., Tibet, China), is a full coverage air shower array, with an energy threshold of ∼300 GeV for gamma-ray astronomy. Most of the recorded events are single front showers, satisfying the trigger requirement of at least 20 particles detected in a given time window. However, in ∼11.5% of the events, two randomly arriving showers may be recorded in the same time window, and the second one, generally smaller, does not need to satisfy the trigger condition. These events are called double shower front events. By using these small showers, well under the trigger threshold, the detector primary energy threshold can be lowered to a few tens of GeV. In this paper, the angular resolution that can be achieved with these events is evaluated by a full Monte Carlo simulation. The ARGO-YBJ sensitivity in detecting gamma-ray bursts (GRBs) by using double shower front events is also studied for various cutoff energies, time durations, and zenith angles of GRBs in ARGO’s field of view. Supported by National Natural Science Foundation of China (11475141) and Fundamental Research Funds for Central Universities (2682014CX091)

  8. Hadron shower decomposition in the highly granular CALICE analogue hadron calorimeter

    NASA Astrophysics Data System (ADS)

    Eigen, G.; Price, T.; Watson, N. K.; Marshall, J. S.; Thomson, M. A.; Ward, D. R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Dotti, A.; Folger, G.; Ivantchenko, V.; Ribon, A.; Uzhinskiy, V.; Hostachy, J.-Y.; Morin, L.; Brianne, E.; Ebrahimi, A.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Irles, A.; Krivan, F.; Krüger, K.; Kvasnicka, J.; Lu, S.; Lutz, B.; Morgunov, V.; Neubüser, C.; Provenza, A.; Reinecke, M.; Sefkow, F.; Schuwalow, S.; Tran, H. L.; Garutti, E.; Laurien, S.; Matysek, M.; Ramilli, M.; Schröder, S.; Briggl, K.; Eckert, P.; Munwes, Y.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; van Doren, B.; Wilson, G. W.; Kawagoe, K.; Hirai, H.; Sudo, Y.; Suehara, T.; Sumida, H.; Takada, S.; Tomita, T.; Yoshioka, T.; Wing, M.; Bonnevaux, A.; Combaret, C.; Caponetto, L.; Grenier, G.; Han, R.; Ianigro, J. C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Steen, A.; Berenguer Antequera, J.; Calvo Alamillo, E.; Fouz, M.-C.; Marin, J.; Puerta-Pelayo, J.; Verdugo, A.; Bobchenko, B.; Markin, O.; Novikov, E.; Rusinov, V.; Tarkovsky, E.; Kirikova, N.; Kozlov, V.; Smirnov, P.; Soloviev, Y.; Besson, D.; Buzhan, P.; Chadeeva, M.; Danilov, M.; Drutskoy, A.; Ilyin, A.; Mironov, D.; Mizuk, R.; Popova, E.; Gabriel, M.; Goecke, P.; Kiesling, C.; van der Kolk, N.; Simon, F.; Szalay, M.; Bilokin, S.; Bonis, J.; Cornebise, P.; Pöschl, R.; Richard, F.; Thiebault, A.; Zerwas, D.; Anduze, M.; Balagura, V.; Becheva, E.; Boudry, V.; Brient, J.-C.; Cizel, J.-B.; Clerc, C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Magniette, F.; Mora de Freitas, P.; Musat, G.; Pavy, S.; Rubio-Roy, M.; Ruan, M.; Videau, H.; Callier, S.; Dulucq, F.; Martin-Chassard, G.; Raux, L.; Seguin-Moreau, N.; de la Taille, Ch.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Kotera, K.; Ono, H.; Takeshita, T.; Ieki, S.; Kamiya, Y.; Ootani, W.; Shibata, N.; Jeans, D.; Komamiya, S.; Nakanishi, H.

    2016-06-01

    The spatial development of hadronic showers in the CALICE scintillator-steel analogue hadron calorimeter is studied using test beam data collected at CERN and FNAL for single positive pions and protons with initial momenta in the range of 10-80 GeV/c. Both longitudinal and radial development of hadron showers are parametrised with two-component functions. The parametrisation is fit to test beam data and simulations using the QGSP_BERT and FTFP_BERT physics lists from GEANT4 version 9.6. The parameters extracted from data and simulated samples are compared for the two types of hadrons. The response to pions and the ratio of the non-electromagnetic to the electromagnetic calorimeter response, h/e, are estimated using the extrapolation and decomposition of the longitudinal profiles.

  9. A Comparison of Two Methods for Initiating Air Mass Back Trajectories

    NASA Astrophysics Data System (ADS)

    Putman, A.; Posmentier, E. S.; Faiia, A. M.; Sonder, L. J.; Feng, X.

    2014-12-01

    Lagrangian air mass tracking programs in back cast mode are a powerful tool for estimating the water vapor source of precipitation events. The altitudes above the precipitation site where particle's back trajectories begin influences the source estimation. We assume that precipitation comes from water vapor in condensing regions of the air column, so particles are placed in proportion to an estimated condensation profile. We compare two methods for estimating where condensation occurs and the resulting evaporation sites for 63 events at Barrow, AK. The first method (M1) uses measurements from a 35 GHz vertically resolved cloud radar (MMCR), and algorithms developed by Zhao and Garrett1 to calculate precipitation rate. The second method (M2) uses the Global Data Assimilation System reanalysis data in a lofting model. We assess how accurately M2, developed for global coverage, will perform in absence of direct cloud observations. Results from the two methods are statistically similar. The mean particle height estimated by M2 is, on average, 695 m (s.d. = 1800 m) higher than M1. The corresponding average vapor source estimated by M2 is 1.5⁰ (s.d. = 5.4⁰) south of M1. In addition, vapor sources for M2 relative to M1 have ocean surface temperatures averaging 1.1⁰C (s.d. = 3.5⁰C) warmer, and reported ocean surface relative humidities 0.31% (s.d. = 6.1%) drier. All biases except the latter are statistically significant (p = 0.02 for each). Results were skewed by events where M2 estimated very high altitudes of condensation. When M2 produced an average particle height less than 5000 m (89% of events), M2 estimated mean particle heights 76 m (s.d. = 741 m) higher than M1, corresponding to a vapor source 0.54⁰ (s.d. = 4.2⁰) south of M1. The ocean surface at the vapor source was an average of 0.35⁰C (s.d. = 2.35⁰C) warmer and ocean surface relative humidities were 0.02% (s.d. = 5.5%) wetter. None of the biases was statistically significant. If the vapor source

  10. Advancing the U.S. Air Force’s Force-Development Initiative

    DTIC Science & Technology

    2007-01-01

    for far larger numbers of midcareer positions. We believe the FMDC and its members should play important roles in shaping, advocating, coordinating...improved the monograph’s organization and pre- sentation; and Ray Conley, Brent Thomas, and Manuel Carrillo played key roles in analyzing colonel jobs...Initiative 13 Preparatory roles . Some jobs are important for preparing and/or testing colonels as candidates for promotion to general officer

  11. 14 CFR 93.25 - Initial assignment of Arrival Authorizations to U.S. and Canadian air carriers for domestic and U...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Initial assignment of Arrival...) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Congestion and Delay Reduction at... this rule, Arrival Authorizations for each scheduled arrival that it published for either domestic or...

  12. Comparison of a Follow-On Analysis and Initial Findings of a Survey of the Perceived Quality of Life of Air Force People

    DTIC Science & Technology

    1979-09-07

    being, his satis- faction or dissatisfaction with life , or happiness or unhappiness [17:11]. Dr. Ben-Chieh Liu has defined QOL as: . . . the output...FOLLOW-ON ANALYSIS AND INITIAL FINDINGS OF A SURVEY OF THE PERCEIVED QUALITY OF LIFE OF AIR FORCE PEOPLE , /•’ / William L./George; Captain...A FOLLOW-ON ANALYSIS AND INITIAL FINDINGS OF A SURVEY OF THE PERCLiVED QUALITY OF LIFE OF AIR FORCE PEOPLE 5 TYPE OF REPORT & PERIOO COVERED

  13. Milagro: A low energy threshold extensive air shower array

    SciTech Connect

    Sinnis, C.

    1994-12-31

    Observations of high-energy gamma rays from astronomical sources have revolutionized our view of the cosmos. Gamma rays with energies up to {approximately}10 GeV can be observed directly with space-based instruments. Above 100 GeV the low flux of gamma rays requires one to utilize ground-based instruments. Milagro is a new type of gamma-ray detector based on water Cerenkov technology. This new design will enable to continuously observe the entire overhead sky, and be sensitive to cosmic rays with energies above {approximately}250 GeV. These attributes make Milagro an ideal detector for the study of high-energy transient phenomenon.

  14. The prediction of meteor showers from all potential parent comets

    NASA Astrophysics Data System (ADS)

    Neslušan, Luboš; Hajduková, Mária; Tomko, Dušan; Kaňuchová, Zuzana; Jakubík, Marián

    2014-02-01

    The objectives of this project are to predict new meteor showers associated with as many as possible known periodic comets and to find a generic relationship of some already known showers with these comets. For a potential parent comet, we model a theoretical stream at the moment of its perihelion passage in a far past, and follow its dynamical evolution until the present. Subsequently, we analyze the orbital characteristics of the parts of the stream that approach the Earth's orbit. Modelled orbits of the stream particles are compared with the orbits of actual photographic, video, and radar meteors from several catalogues. The whole procedure is repeated for several past perihelion passages of the parent comet. To keep our description compact but detailed, we usually present only either a single or a few parent comets with their associated showers in one paper. Here, an overview of the results from the modelling of the meteor-shower complexes of more than ten parent bodies will be presented. This enables their diversities to be shown. Some parent bodies may associate meteor showers which exhibit a symmetry of their radiant areas with respect to the ecliptic (ecliptical, toroidal, or showers of an ecliptic-toroidal structure), and there are showers which have no counterpart with a similar ecliptical longitude on the opposite hemisphere. However, symmetry of the radiant areas of the pair filaments with respect to the Earth's apex is visible in almost all the complexes which we examined.

  15. Hadronic Showers in a Highly Granular Imaging Calorimeter

    NASA Astrophysics Data System (ADS)

    Kaplan, A.; The Calice Collaboration

    The CALICE collaboration develops highly granular calorimeter prototypes to evaluate technologies for experiments at a future lepton collider. The analogue hadronic calorimeter prototype consists of steel absorber plates interleaved with 38 active plastic scintillator layers which are sub-divided into small tiles. In total 7608 tiles are read out individually via embedded Silicon Photomultipliers. The prototype is one of the first large scale applications of these novel and very promising miniature photodetectors. Since 2006, the calorimeter has been operated in combined test beam setups at DESY, CERN and FNAL. The high-resolution 3D image data with analogue energy information are used to study properties and composition of hadronic showers at a new level of detail. This helps to constrain hadronic shower models through comparisons with model calculations. The spatial shower development and the substructure of the showers, compared to a variety of different Geant 4 shower models including decompositions into individual shower components are presented. Aspects of the energy reconstruction of hadronic showers, such as Particle Flow, are discussed.

  16. CAMS newly detected meteor showers and the sporadic background

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.; Nénon, Q.; Gural, P. S.; Albers, J.; Haberman, B.; Johnson, B.; Morales, R.; Grigsby, B. J.; Samuels, D.; Johannink, C.

    2016-03-01

    The Cameras for Allsky Meteor Surveillance (CAMS) video-based meteoroid orbit survey adds 60 newly identified showers to the IAU Working List of Meteor Showers (numbers 427, 445-446, 506-507, and part of 643-750). 28 of these are also detected in the independent SonotaCo survey. In total, 230 meteor showers and shower components are identified in CAMS data, 177 of which are detected in at least two independent surveys. From the power-law size frequency distribution of detected showers, we extrapolate that 36% of all CAMS-observed meteors originated from ∼700 showers above the N = 1 per 110,000 shower limit. 71% of mass falling to Earth from streams arrives on Jupiter-family type orbits. The transient Geminids account for another 15%. All meteoroids not assigned to streams form a sporadic background with highest detected numbers from the apex source, but with 98% of mass falling in from the antihelion source. Even at large ∼7-mm sizes, a Poynting-Robertson drag evolved population is detected, which implies that the Grün et al. collisional lifetimes at these sizes are underestimated by about a factor of 10. While these large grains survive collisions, many fade on a 104-y timescale, possibly because they disintegrate into smaller particles by processes other than collisions, leaving a more resilient population to evolve.

  17. COMET SHOWERS ARE NOT INDUCED BY INTERSTELLAR CLOUDS

    SciTech Connect

    Morris, D.E.

    1985-11-01

    Encounters with interstellar clouds (IC) have been proposed by Rampino and Stothers as a cause of quasi-periodic intense comet showers leading to earth impacts, in order to explain the periodicity in marine mass extinctions found by Raup and Sepkoski. The model was described further, criticized and defended. The debate has centered on the question of whether the scale height of the clouds is small enough (in comparison to the amplitude of the oscillation of the solar system about the plane of the Galaxy) to produce a modulation in the rate of encounters. We wish to point out another serious, we believe fatal, defect in this model - the tidal fields of ICs are not strong enough to produce intense comet showers leading to earth impacts by bringing comets of the postulated inner Oort cloud into earth crossing orbits, except possibly during very rare encounters with very dense clouds. We will show that encounters with abundant clouds of low density cannot produce comet showers; cloud density N > 10{sup 3} atoms cm{sup -3} is needed to produce an intense comet shower leading to earth impacts. Furthermore, the tidal field of a dense cloud during a distant encounter is too weak to produce such showers. As a consequence, comet showers induced by ICs will be far less frequent than showers caused by passing stars. This conclusion is independent of assumptions about the radial distribution of comets in the inner Oort cloud.

  18. Radiation damage due to electromagnetic showers

    SciTech Connect

    Rakhno, Igor; Mokhov, Nikolai; Striganov, Sergei; /Fermilab

    2008-05-01

    Radiation-induced damage due to atomic displacements is essential to correctly predict the behavior of materials in nuclear reactors and at charged-particle accelerators. Traditionally the damage due to hadrons was of major interest. The recent increased interest in high-energy lepton colliders gave rise to the problem of prediction of radiation damage due to electromagnetic showers in a wide energy range--from a few hundred keV and up to a few hundred GeV. The report describes results of an electron- and positron-induced displacement cross section evaluation. It is based on detailed lepton-nucleus cross sections, realistic nuclear form-factors and a modified Kinchin-Pease damage model. Numerical data on displacement cross sections for various target nuclei is presented.

  19. Monte Carlo modeling and meteor showers

    NASA Technical Reports Server (NTRS)

    Kulikova, N. V.

    1987-01-01

    Prediction of short lived increases in the cosmic dust influx, the concentration in lower thermosphere of atoms and ions of meteor origin and the determination of the frequency of micrometeor impacts on spacecraft are all of scientific and practical interest and all require adequate models of meteor showers at an early stage of their existence. A Monte Carlo model of meteor matter ejection from a parent body at any point of space was worked out by other researchers. This scheme is described. According to the scheme, the formation of ten well known meteor streams was simulated and the possibility of genetic affinity of each of them with the most probable parent comet was analyzed. Some of the results are presented.

  20. Meteor showers on the Earth from sungrazers

    NASA Astrophysics Data System (ADS)

    Sekhar, A.; Asher, D.

    2014-07-01

    1. C/2012 S1 (ISON) and C/1680 V1 (Newton's comet): Only very few past works [1,2,3] have looked into the aspects of meteor phenomena from sungrazing comets. Here we study whether feasible meteoroid ejection velocities in ISON and Newton's comet could bring the nodes close to the Earth's orbit so as to cause a visually spectacular meteor shower. Detailed analysis using Lagrange's planetary equations [4] shows that even at very high ejection velocities (˜ 1 km/s), the descending nodes of the meteoroids reach only 0.91 au (quite close to the Earth's orbit; which in itself is very rare for sungrazing orbits) in the case of ISON. For Newton's comet, the required ejection velocities are about 800 m/s for the descending node to reach 1 au. Such high ejection velocities are practically rare for big meteoroids (˜ 1 mm in diameter) which encounter Earth and hence spectacular visual meteor activity can be ruled out completely [5]. 2. Marsden Group versus other Sungrazing Families: A similar analysis using Lagrange's equations [6,7] was done on all the known sungrazing families [8]. We find that, only in the Marsden family, it could lead to substantial nodal dispersion in meteoroids so that the descending nodes can encounter Earth at ejection velocities of the order of few 100 m/s. This matches with the earlier significant works [1,2,9] which linked the Daytime Arietids (ARI) to the Marsden group. The fact that only a very small number of sungrazing orbits favour Earth intersection at low ejection velocities (out of the observed families so far) stands as the primary reason for the absence of regular meteor showers from them although sungrazers in itself are very frequent.

  1. Inhalation exposure to haloacetic acids and haloketones during showering.

    PubMed

    Xu, Xu; Weisel, Clifford P

    2003-02-01

    Inhalation exposure to haloacetic acids (HAAs) and haloketones (HKs) in contaminated drinking water occurs during showering. The size distribution of the aerosols generated by a shower was determined using an eight size-range particle counter, which measured particles from 0.1 to >2 microm. An exponential increase in aerosol numbers was observed while the shower water was on, while the aerosol numbers declined exponentially once the water was turned off. The half-lives of the shower aerosols were longer than 5 min after the shower water was turned off. Although the majority of the shower-generated aerosols were smaller than 0.3 microm, these aerosols only contributed approximately 2% to the measured total aerosol mass. The total shower-generated particulate HAA and HK concentrations collected on an open face filter were approximately 6.3 and 0.13 microg/m3, respectively, for shower water HAA and HK concentrations of 250 and 25 microg/L, respectively. The vapor-phase HK concentrations were 25-50 microg/m3. The estimate of the dose from inhalation exposure of disinfection byproducts (DBPs) in the particulate phase indicate that they represent less than 1% of the ingestion dose, so inhalation is not expected to be an important exposure route to nonvolatile water contaminants or the portion of volatile DBPs that stay in the particulate phase, unless the lung is the target organ. The vapor-phase levels of volatile HKs, though, are significantly higher and can contribute greater than 10% of the ingestion dose during a shower. Thus, risk assessment to the these DBPs needs to consider the inhalation route.

  2. Free Flight Simulation: An Initial Examination of Air-Ground Integration Issues

    NASA Technical Reports Server (NTRS)

    Lozito, Sandra; McGann, Alison; Cashion, Patricia; Dunbar, Melisa; Mackintosh, Margaret; Dulchinos, Victoria; Jordan, Kevin; Remington, Roger (Technical Monitor)

    2000-01-01

    The concept of "free flight" is intended to emphasize more flexibility for operators in the National Airspace System (RTCA, 1995). This may include the potential for aircraft self-separation. The purpose of this simulation was to begin examining some of the communication and procedural issues associated with self-separation in an integrated air-ground environment. Participants were 10 commercial U.S. flight crews who flew the B747-400 simulator and 10 Denver ARTCC controllers who monitored traffic in an ATC simulation. A prototypic airborne alerting logic and flight deck display features were designed to allow for increased traffic and maneuvering information. Eight different scenarios representing different conflict types were developed. The effects of traffic density (high and low) and different traffic convergence angles (obtuse, acute, and right) were assessed. Conflict detection times were found to be lower for the flight crews in low density compared to high density scenarios. For the controllers, an interaction between density and convergence angle was revealed. Analyses on the controller detection times found longer detection times in the obtuse high density compared to obtuse low density, as well as the shortest detection times in the high density acute angle condition. Maneuvering and communication events are summarized, and a discussion of future research issues is provided.

  3. The 2017 Meteor Shower Activity Forecast for Earth Orbit

    NASA Technical Reports Server (NTRS)

    Moorehead, Althea; Cooke, Bill; Moser, Danielle

    2017-01-01

    Most meteor showers will display typical activity levels in 2017. Perseid activity is expected to be higher than normal but less than in 2016; rates may reach 80% of the peak ZHR in 2016. Despite this enhancement, the Perseids rank 4th in flux for 0.04-cm-equivalent meteoroids: the Geminids (GEM), Daytime Arietids (ARI), and Southern delta Aquariids (SDA) all produce higher fluxes. Aside from heightened Perseid activity, the 2017 forecast includes a number of changes. In 2016, the Meteoroid Environment Office used 14 years of shower flux data to revisit the activity profiles of meteor showers included in the annual forecast. Both the list of showers and the shape of certain major showers have been revised. The names and three-letter shower codes were updated to match those in the International Astronomical Union (IAU) Meteor Data Center, and a number of defunct or insignificant showers were removed. The most significant of these changes are the increased durations of the Daytime Arietid (ARI) and Geminid (GEM) meteor showers. This document is designed to supplement spacecraft risk assessments that incorporate an annual averaged meteor shower flux (as is the case with all NASA meteor models). Results are presented relative to this baseline and are weighted to a constant kinetic energy. Two showers - the Daytime Arietids (ARI) and the Geminids (GEM) - attain flux levels approaching that of the baseline meteoroid environment for 0.1-cm-equivalent meteoroids. This size is the threshold for structural damage. These two showers, along with the Quadrantids (QUA) and Perseids (PER), exceed the baseline flux for 0.3-cm-equivalent particles, which is near the limit for pressure vessel penetration. Please note, however, that meteor shower fluxes drop dramatically with increasing particle size. As an example, the Arietids contribute a flux of about 5x10(exp -6) meteoroids m(exp -2) hr-1 in the 0.04-cm-equivalent range, but only 1x10(exp -8) meteoroids m(sub -2) hr-1 for the 0

  4. Mechanism of the Initial Oxidation of Hydrogen andHalogen Terminated Ge(111) Surfaces in Air

    SciTech Connect

    Sun, Shiyu; Sun, Yun; Liu, Zhi; Lee, Dong-Ick; Pianetta, Piero; /SLAC, SSRL

    2006-08-23

    The initial stage of the oxidation of Ge(111) surfaces etched by HF, HCl and HBr solutions is systematically studied using synchrotron radiation photoelectron spectroscopy (SR-PES). We perform controlled experiments to differentiate the effects of different oxidation factors. SR-PES results show that both moisture and oxygen contribute to the oxidation of the surfaces; however, they play different roles in the oxidation process. Moisture effectively replaces the hydrogen and halogen termination layers with hydroxyl (OH), but hardly oxidizes the surfaces further. On the other hand, dry oxygen does not replace the termination layers, but breaks the Ge-Ge back bonds and oxidizes the substrates with the aid of moisture. In addition, room light enhances the oxidation rate significantly.

  5. Evaluation of COSMO-ART in the Framework of the Air Quality Model Evaluation International Initiative (AQMEII)

    NASA Astrophysics Data System (ADS)

    Giordano, Lea; Brunner, Dominik; Im, Ulas; Galmarini, Stefano

    2014-05-01

    The Air Quality Model Evaluation International Initiative (AQMEII) coordinated by the EC-JRC and US-EPA, promotes since 2008 research on regional air quality model evaluation across the atmospheric modelling communities of Europe and North America. AQMEII has now reached its Phase 2 that is dedicated to the evaluation of on-line coupled chemistry-meteorology models as opposed to Phase 1 where only off-line models were considered. At European level, AQMEII collaborates with the COST Action "European framework for on-line integrated air quality and meteorology modelling" (EuMetChem). All European groups participating in AQMEII performed simulations over the same spatial domain (Europe at a resolution of about 20 km) and using the same simulation strategy (e.g. no nudging allowed) and the same input data as much as possible. The initial and boundary conditions (IC/BC) were shared between all groups. Emissions were provided by the TNO-MACC database for anthropogenic emissions and the FMI database for biomass burning emissions. Chemical IC/BC data were taken from IFS-MOZART output, and meteorological IC/BC from the ECWMF global model. Evaluation data sets were collected by the Joint Research Center (JRC) and include measurements from surface in situ networks (AirBase and EMEP), vertical profiles from ozone sondes and aircraft (MOZAIC), and remote sensing (AERONET, satellites). Since Phase 2 focuses on on-line coupled models, a special effort is devoted to the detailed speciation of particulate matter components, with the goal of studying feedback processes. For the AQMEII exercise, COSMO-ART has been run with 40 levels of vertical resolution, and a chemical scheme that includes the SCAV module of Knote and Brunner (ACP 2013) for wet-phase chemistry and the SOA treatment according to VBS (volatility basis set) approach (Athanasopoulou et al., ACP 2013). The COSMO-ART evaluation shows that, next to a good performance in the meteorology, the gas phase chemistry is well

  6. Femtosecond filament initiated, microwave heated cavity-free nitrogen laser in air

    NASA Astrophysics Data System (ADS)

    Kartashov, Daniil; Shneider, Mikhail N.

    2017-03-01

    We present the results of numerical modeling of the igniter-heater concept for initiation of standoff, cavity free lasing action in the atmosphere when a femtosecond laser filament is used for plasma generation (igniter) and a microwave heater provides electron-collision pumping of electronic states in molecular nitrogen. By solving numerically the kinetic equation for the energy distribution function of electrons, generated in a femtosecond laser filament and heated by a microwave beam, we identify the conditions enabling single-pass, standoff UV-laser from molecular nitrogen in the atmosphere. The plasma density, the minimum amplitude of the microwave field, and the small-signal gain, necessary to achieve the lasing, are determined. We demonstrate that lasing build up time can be minimized and efficiency improved by using elliptically polarized laser pulses for filamentation. It is shown that realization of the filament-igniter, microwave-heater concept of the sky laser at low altitudes would require a microwave source of hundreds of kilowatt-megawatt power. The required microwave power can be reduced by several orders of magnitude when the igniter-heater scheme is used at the 10-30 km range of altitudes.

  7. Recent federal initiatives to promote unconventional gas: High octane delivery of just hot air?

    SciTech Connect

    Griff, M.T.

    1995-10-01

    This paper provides an overview of recent initiatives of the United States which promote greater use of natural gas and unconventional gas as one part of this nations`s larger response to the global warming threat. Measurable increases in greenhouse gas concentrations since the beginning of the industrial revolution have led to the belief in the existence of a global warming problem. The international community has responded to the global warming threat with the United Nations Framework Convention on Climate Change which is directed toward the stabilization of greenhouse gases in the atmosphere. The Climate Change Action Plan is the Clinton Administration`s detailed response to the global warming threat. It is designed to return United States emissions of greenhouse gases to their 1990 levels by the year 2000. The Action Plan targets all greenhouse gases and emphasizes energy efficiency. Significant regulatory reformation designed to increase the efficiency of the natural gas industry has already occurred and will be continued. Recovery of methane emissions from landfills will be encouraged through indentification of suitable sites and use of existing technology and development of new technology. Recovery of methane from coal mining operations will be promoted by targeting 50 of the gassiest mines in the United States. Even if the Action Plan is fully implemented. legitimate questions arise as to whether its goals will be achieved as a result of funding shortfalls.

  8. Top-pair production and decay at NLO matched with parton showers

    DOE PAGES

    Campbell, John M.; Ellis, R. Keith; Nason, Paolo; ...

    2015-04-21

    We present a next-to-leading order (NLO) calculation of tt¯ production in hadronic collisions interfaced to shower generators according to the POWHEG method. We start from an NLO result from previous work, obtained in the zero width limit, where radiative corrections to both production and decays are included. The POWHEG interface required an extension of the POWHEG BOX framework, in order to deal with radiation from the decay of resonances. This extension is fully general (i.e. it can be applied in principle to any process considered in the zero width limit), and is here applied for the first time. In ordermore » to perform a realistic simulation, we introduce finite width effects using different approximations, that we validated by comparing with published exact NLO results. We have interfaced our POWHEG code to the PYTHIA8 shower Monte Carlo generator. At this stage, we dealt with novel issues related to the treatment of resonances, especially with regard to the initial scale for the shower that needs to be set appropriately. This procedure affects, for example, the fragmentation function of the b quark, that we have studied with particular attention. We believe that the tool presented here improves over previous generators for all aspects that have to do with top decays, and especially for the study of issues related to top mass measurements that involve B hadrons or b jets. As a result, the work presented here also constitutes a first step towards a fully consistent matching of NLO calculations involving intermediate resonances decaying into coloured particles, with parton showers.« less

  9. Kappa Group: The initial guess. A proposal in response to a commercial air transportation study

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Kappa Aerospace presents their Aeroworld Aircraft, the Initial Guess (IG). This aircraft is designed to generate profit in the market which is currently controlled by the train and boat industry. The main priority of the design team was to develop an extremely efficient aircraft that could be sold at a reasonable price. The IG offers a quick and safe alternative to the existing means of transportation at a competitive price. The cruise velocity of 28 ft/sec. allows all flights to be between 20 and 45 minutes, which is a remarkable savings in time compared to travel by boat or train. The IG is propelled by a single Astro-05 engine with a Zinger 10-6 propeller. The Astro-05 is not an extremely powerful engine; however, it provides enough thrust to meet the design and safety requirements. The major advantage of the Astro-05 is that it is the most efficient engine available. The fuel efficiency of the Astro-05 is what puts the aircraft ahead of the competition. The money saved on an efficient engine can be passed on as lower ticket prices or increased revenue. The IG has a payload of 56 passengers and a wingspan of 7 ft. The 7 ft. wingspan allows the aircraft to fit into the gates of all of the cities that are targeted. Future endeavors of Kappa Aerospace will include fitting a stretch version of the IG with a larger propulsion system. This derivative aircraft will be able to carry more passengers and will be placed on the routes which have the greatest demand for travel. The fuselage and empennage are made of a wooden truss configuration, while the wing is made of a rib/spare configuration. The stress carrying elements are made of spruce, the nonstress carrying elements are made of balsa. The wing is removable for easy access into the fuselage. The easy access to the batteries will keep maintenance costs down.

  10. Martian Atmospheric Methane Plumes from Meteor Shower Infall: A Hypothesis

    NASA Astrophysics Data System (ADS)

    Fries, M.; Christou, A.; Archer, D.; Conrad, P.; Cooke, W.; Eigenbrode, J.; ten Kate, I. L.; Matney, M.; Niles, P.; Sykes, M.; Steele, A.; Treiman, A.

    2016-09-01

    Methane plumes in the martian atmosphere were previously reported, but their source remains a mystery. We hypothesize a meteor shower source, as we find a correlation between Mars/cometary orbit encounters and detections of plumes.

  11. 28. SHOWER AND URINALS, OVERHEAD TOILET STRUCTURE ABOVE ROOF PANEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. SHOWER AND URINALS, OVERHEAD TOILET STRUCTURE ABOVE ROOF PANEL STORAGE AREA. VIEW TO SOUTH-SOUTHWEST. - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  12. 27. OVERHEAD TOILET, SHOWER, CHANGE ROOM STRUCTURE. VIEW TO NORTHNORTHEAST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. OVERHEAD TOILET, SHOWER, CHANGE ROOM STRUCTURE. VIEW TO NORTH-NORTHEAST. - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  13. "Shower head" water connection for servicing railroad locomotives, perspective view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    "Shower head" water connection for servicing railroad locomotives, perspective view looking NW across ATSF railyard. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  14. FACILITY 846, TOILET AND SHOWER WINGS, QUADRANGLE J, OBLIQUE VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FACILITY 846, TOILET AND SHOWER WINGS, QUADRANGLE J, OBLIQUE VIEW FACING WEST. - Schofield Barracks Military Reservation, Quadrangles I & J Barracks Type, Between Wright-Smith & Capron Avenues near Williston Avenue, Wahiawa, Honolulu County, HI

  15. 10. NEEDLE SHOWER IN COOLING ROOM. Hot Springs National ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. NEEDLE SHOWER IN COOLING ROOM. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  16. 9. NEEDLE SHOWER IN MEN'S PACK ROOM. Hot Springs ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. NEEDLE SHOWER IN MEN'S PACK ROOM. - Hot Springs National Park Bathhouse Row, Maurice Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  17. Test results of a shower water recovery system

    NASA Technical Reports Server (NTRS)

    Verostko, Charles E.; Price, Donald F.; Garcia, Rafael; Pierson, Duane L.; Sauer, Richard L.

    1987-01-01

    A shower test was conducted recently at NASA-JSC in which waste water was reclaimed and reused. Test subjects showered in a prototype whole body shower following a protocol similar to that anticipated for Space Station. The waste water was purified using reverse osmosis followed by filtration through activated carbon and ion exchange resin beds. The reclaimed waste water was maintained free of microorganisms by using both heat and iodine. This paper discusses the test results, including the limited effectiveness of using iodine as a disinfectant and the evaluation of a Space Station candidate soap for showering. In addition, results are presented on chemical and microbial impurity content of water samples obtained from various locations in the water recovery process.

  18. Men's shower room at east end of the building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Men's shower room at east end of the building - Fitzsimons General Hospital, Swimming Pool, Southeast corner of East Nineteenth Place (formerly East McAfee Avenue) & Wheeling Street (formerly South Van Valzah Street), Aurora, Adams County, CO

  19. E.M. and Hadronic Shower Simulation with FLUKA

    SciTech Connect

    Battistoni, G.; Fasso, A.; Ferrari, A.; Ranft, J.; Rubbia, A.; Sala, P.R.; /INFN, Milan /SLAC /CERN /Siegen U. /Zurich, ETH

    2005-10-03

    A description of the main features of e.m. and hadronic shower simulation models used in the FLUKA code is summarized and some recent applications are discussed. The general status of the FLUKA project is also reported.

  20. Interior view of shower room 216 with original marble surround ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of shower room 2-16 with original marble surround and double sash windows, facing east. - Marine Barracks, Panama Canal, Barracks Building, 100' North of Thatcher Highway, Balboa, Former Panama Canal Zone, CZ

  1. 61. SOUTH PLANT ETHYLENE GENERATOR BUILDING, WITH EMERGENCY SHOWER AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    61. SOUTH PLANT ETHYLENE GENERATOR BUILDING, WITH EMERGENCY SHOWER AT LEFT FOREGROUND. VIEW TO WEST. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO

  2. National Security Science and Technology Initiative: Air Cargo Screening, Final Report for CRADA Number NFE-07-01081

    SciTech Connect

    Bingham, Philip; Bush, John; Bowerman, Biays; Cespedes, Ernesto; White, Timothy

    2004-12-01

    The non-intrusive inspection (NII) of consolidated air cargo carried on commercial passenger aircraft continues to be a technically challenging, high-priority requirement of the Department of Homeland Security’s Science and Technology Directorate (DHS S&T), the Transportation Security Agency and the Federal Aviation Administration. The goal of deploying a screening system that can reliably and cost-effectively detect explosive threats in consolidated cargo without adversely affecting the flow of commerce will require significant technical advances that will take years to develop. To address this critical National Security need, the Battelle Memorial Institute (Battelle), under a Cooperative Research and Development Agreement (CRADA) with four of its associated US Department of Energy (DOE) National Laboratories (Oak Ridge, Pacific Northwest, Idaho, and Brookhaven), conducted a research and development initiative focused on identifying, evaluating, and integrating technologies for screening consolidated air cargo for the presence of explosive threats. Battelle invested $8.5M of internal research and development funds during fiscal years 2007 through 2009.

  3. Multi-Year CMOR Observations of the Geminid Meteor Shower

    NASA Technical Reports Server (NTRS)

    Webster, A. R.; Jones, J.

    2011-01-01

    The three-station Canadian Meteor Orbit Radar (CMOR) is used here to examine the Geminid meteor shower with respect to variation in the stream properties including the flux and orbital elements over the period of activity in each of the consecutive years 2005 2008 and the variability from year to year. Attention is given to the appropriate choice and use of the D-criterion in the separating the shower meteors from the sporadic background.

  4. Meteorites from meteor showers: A case study of the Taurids

    NASA Astrophysics Data System (ADS)

    Brown, Peter; Marchenko, Valerie; Moser, Danielle E.; Weryk, Robert; Cooke, William

    2013-02-01

    We propose that the Taurid meteor shower may contain bodies able to survive and be recovered as meteorites. We review the expected properties of meteorite-producing fireballs, and suggest that end heights below 35 km and terminal speeds below 10 km s-1 are necessary conditions for fireballs expected to produce meteorites. Applying the meteoroid strength index (PE criteria) of Ceplecha and McCrosky (1976) to a suite of 33 photographically recorded Taurid fireballs, we find a large spread in the apparent meteoroid strengths within the stream, including some very strong meteoroids. We also examine in detail the flight behavior of a Taurid fireball (SOMN 101031) and show that it has the potential to be a (small) meteorite-producing event. Similarly, photographic observations of a bright, potential Taurid fireball recorded in November of 1995 in Spain show that it also had meteorite-producing characteristics, despite a very high entry velocity (33 km s-1). Finally, we note that the recent Maribo meteorite fall may have had a very high entry velocity (28 km s-1), further suggesting that survival of meteorites at Taurid-like velocities is possible. Application of a numerical entry model also shows plausible survival of meteorites at Taurid-like velocities, provided the initial meteoroids are fairly strong and large, both of which are characteristics found in the Taurid stream.

  5. Automated Optical Meteor Fluxes and Preliminary Results of Major Showers

    NASA Technical Reports Server (NTRS)

    Blaauw, R.; Campbell-Brown, M.; Cooke, W.; Kingery, A.; Weryk, R.; Gill, J.

    2014-01-01

    active shower or sporadic source radiant. The flux per height interval is calculated and summed to obtain the total meteor flux. Both single station and double station fluxes are currently found daily. Geminid fluxes on the peak night in 2012 (12-14-2012) were 0.058 meteors/km2/hr as found with double-station meteors and 0.057 meteors/ km2/hr as found with single-station meteors, to a limiting magnitude of +6.5. Both of those numbers are in agreement with the well-calibrated fluxes from the Canadian Meteor Orbit Radar. Along with flux algorithms and initial flux results, presented will be results from the first 18 months of operation, covering 3,000+ meteoroid orbits.

  6. Investigation of meteor shower parent bodies using various metrics

    NASA Astrophysics Data System (ADS)

    Dumitru, B. A.; Birlan, M.; Nedelcu, A.; Popescu, M.

    2016-01-01

    The present knowledge of meteor showers identifies the small bodies of our Solar System as supply sources for meteor streams. Both comets and asteroids are considered as the origin of meteor showers. The new paradigm of "active asteroids" opens up a large field of investigation regarding the relationships between asteroids and meteors. Processes like ejection and disaggregation at impacts, rotational instabilities, electrostatic repulsion, radiation pressure, dehydration stress followed by thermal fractures, sublimation of ices are sources of matter loss from asteroids. Our objective is to find genetic relationships between asteroids and meteor showers using metrics based on orbital elements. For this objective we selected three metrics (Southworth and Hawkins, 1963; Asher et al. 1993, and Jopek, 1993, respectively), the recent MPC database and the more recent IAU meteor shower database. From our analysis, 41 of the meteor showers have probabilities of being produced (or to be fueled) by asteroids. Our sample of asteroids contains more than 1000 objects, all of them belonging to the Near-Earth Asteroid population. The systematic approach performed, based on the physical properties of our sample, reinforced the link between asteroids and their associated meteor shower.

  7. Validation of the criteria for initiating the cleaning of heating, ventilation, and air-conditioning (HVAC) ductwork under real conditions.

    PubMed

    Lavoie, Jacques; Marchand, Geneviève; Cloutier, Yves; Lavoué, Jérôme

    2011-08-01

    Dust accumulation in the components of heating, ventilation, and air-conditioning (HVAC) systems is a potential source of contaminants. To date, very little information is available on recognized methods for assessing dust buildup in these systems. The few existing methods are either objective in nature, involving numerical values, or subjective in nature, based on experts' judgments. An earlier project aimed at assessing different methods of sampling dust in ducts was carried out in the laboratories of the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST). This laboratory study showed that all the sampling methods were practicable, provided that a specific surface-dust cleaning initiation criterion was used for each method. However, these conclusions were reached on the basis of ideal conditions in a laboratory using a reference dust. The objective of this present study was to validate these laboratory results in the field. To this end, the laboratory sampling templates were replicated in real ducts and the three sampling methods (the IRSST method, the method of the U.S. organization National Air Duct Cleaner Association [NADCA] and that of the French organization Association pour la Prévention et l'Étude de la Contamination [ASPEC]) were used simultaneously in a statistically representative number of systems. The air return and supply ducts were also compared. Cleaning initiation criteria under real conditions were found to be 6.0 mg/100 cm(2) using the IRSST method, 2.0 mg/100 cm(2) using the NADCA method, and 23 mg/100 cm(2) using the ASPEC method. In the laboratory study, the criteria using the same methods were 6.0 for the IRSST method, 2.0 for the NADCA method, and 3.0 for the ASPEC method. The laboratory criteria for the IRSST and NADCA methods were therefore validated in the field. The ASPEC criterion was the only one to change. The ASPEC method therefore allows for the most accurate evaluation of dust accumulation in HVAC

  8. SMQIE: The shower max QIE chip

    SciTech Connect

    James R. Hoff

    1999-06-02

    A QIE-like full-custom chip has been designed by members of the Fermilab PPD/ETT/ES Group as well as members of the CDF/Shower Max Group. This chip contains two channels each with an eight range QIE front end capable of handling charges from roughly 12 fC to roughly 100 pC. Each channel also contains a five-bit flash A-to-D converter, a 38 stage deep FIFO for level 1 trigger delay and storage for holding selected time slices. It communicates with the outside world via LVDS-like differential signals. This chip utilizes a 1.2mm double-metal, double-polysilicon process with a vertical NPN transistor option. It has been prototyped using ORBIT Semiconductor�s Foresight program. As of this writing, it has been submitted to Super Tex (new owner of the ORBIT fabrication facility) for fabrication. However, it has not yet returned from fabrication.

  9. Meteorite Shower in Park Forest, Illinois

    NASA Astrophysics Data System (ADS)

    Martel, L. M. V.

    2004-08-01

    Steven Simon (University of Chicago) and seven colleagues from the University of Chicago, the Planetary Studies Foundation, Harper College, Pacific Northwest National Lab, and the Field Museum in Chicago have classified the meteorite fragments that fell on Chicago's southern suburbs on the night of March 26, 2003. Described as ".. the most densely populated region to be hit by a meteorite shower in modern times," the village of Park Forest is at the center of the strewnfield and fortuitously also happens to be home to the Simon family, who answered scores of phone calls from neighboring meteorite finders. No injuries were reported though plenty of roofs, windows, walls, and cars were hit, and the police department took individual fusion-crusted fragments into custody as evidence. Its chemical and mineralogical compositions establish the Park Forest meteorite as an L5 chondrite, one of the most primitive groups of known meteorites. It is a strongly shocked monomict breccia (a term applied to a breccia made of one kind of rock) with light-colored clasts in a very dark matrix. The team measured cosmic radionuclides in Park Forest and found nearly zero cobalt-56 and high cobalt-60, values that indicate a large preatmospheric mass. They estimate the meteoroid was at least 900 kilograms and possibly as large as 7000 kilograms before it broke apart in the atmosphere, of which only about 30 kilograms of fragments have been recovered.

  10. Meteor showers on Earth from sungrazing comets

    NASA Astrophysics Data System (ADS)

    Sekhar, A.; Asher, D. J.

    2014-01-01

    Sungrazing comets have always captured a lot of interest and curiosity among the general public as well as scientists since ancient times. The perihelion passage of comet C/2012 S1 (ISON) at the end of this year (on 2013 November 28) is an eagerly awaited event. In this work, we do a mathematical study to check whether meteoroids ejected from this comet during its journey around the Sun can produce spectacular meteor phenomena on Earth. Our calculations show that although the orbital elements of this comet are much more favourable than for most sungrazers to have its descending node near the Earth's orbit, even ejection velocities as high as 1 km s-1 do not induce sufficient nodal dispersion to bring meteoroids to Earth intersection during present times. A similar result applies to Newton's comet C/1680 V1 which has surprisingly similar orbital elements, although it is known to be a distinct comet from C/2012 S1. Our analysis also shows that for meteoroids ejected from all known sungrazing groups during recent epochs, only the Marsden family (with required ejection velocities of some hundreds of m s-1) can produce meteor phenomena during present times. In a broader sense, we indicate why we do not observe visually brilliant meteor showers from frequently observed sungrazers.

  11. Biofilms on Hospital Shower Hoses: Characterization and ...

    EPA Pesticide Factsheets

    Although the source of drinking water used in hospitals is commonly, biofilms on water pipelines are refuge to bacteria that survive different disinfection strategies. Drinking water (DW) biofilms are well known to harbor opportunistic pathogens, however, these biofilm communities remain poorly characterized by culture-independent approaches that circumvent the limitations of conventional monitoring efforts. Hence, the frequency of pathogens in DW biofilms and how biofilm members withstand high doses of disinfectants and/or chlorine residuals in the water supply remain speculative, but directly impact public health. The aim of this study was to characterize the composition of microbial communities growing on five hospital shower hoses using both culture-dependent and culture-independent techniques. Two different sequence-based methods were used to characterize the bacterial fractions: 16S rRNA gene sequencing of bacterial cultures and next generation sequencing of metagenomes. Based on the metagenomic data, we found that Mycobacterium-like species was the abundant bacterial taxa that overlapped among the five samples. We also recovered the draft genome of a novel Mycobacterium species, closely related to opportunistic pathogenic nontuberculous mycobacteria, M. rhodesiae and M. tusciae, in addition to other, less abundant species. In contrast, the cultured fraction was mostly affiliated to Proteobacteria, such as members of the Sphingomonas, Blastomonas and Porph

  12. The Working Group on Meteor Showers Nomenclature: a History, Current Status and a Call for Contributions

    NASA Technical Reports Server (NTRS)

    Jopek, T. J.; Jenniskens, P. M.

    2011-01-01

    During the IAU General Assembly in Rio de Janeiro in 2009, the members of Commission 22 established the Working Group on Meteor Shower Nomenclature, from what was formerly the Task Group on Meteor Shower Nomenclature. The Task Group had completed its mission to propose a first list of established meteor showers that could receive officially names. At the business meeting of Commission 22 the list of 64 established showers was approved and consequently officially accepted by the IAU. A two-step process is adopted for showers to receive an official name from the IAU: i) before publication, all new showers discussed in the literature are first added to the Working List of Meteor Showers, thereby receiving a unique name, IAU number and three-letter code; ii) all showers which come up to the verification criterion are selected for inclusion in the List of Established Meteor Showers, before being officially named at the next IAU General Assembly.

  13. VizieR Online Data Catalog: Separation and confirmation of showers (Neslusan+, 2017)

    NASA Astrophysics Data System (ADS)

    Neslusan, L.; Hajdukova, M. Jr.

    2016-11-01

    To separate the showers, we simultaneously used two methods. The use of two methods enables us to compare their results, and this can indicate the reliability of the methods. To evaluate the statistical significance, we suggest a new method based on the ideas of the break-point method. We give a compilation of the showers from all four databases using both methods. Using the first (second) method, we separated 107 (133) showers, which are in at least one of the databases used. These relatively low numbers are a consequence of discarding any candidate shower with a poor statistical significance. Most of the separated showers were identified as meteor showers from the IAU MDC list of all showers. Many of them were identified as several of the showers in the list. This proves that many showers have been named multiple times with different names. (2 data files).

  14. Associations between showering behaviours following physical education, physical activity and fitness in English schoolchildren.

    PubMed

    Sandercock, Gavin R H; Ogunleye, Ayodele; Voss, Christine

    2016-01-01

    We aimed to describe the frequency of showering after physical education (PE) in English high-school pupils. We examined differences in physical activity (PA) and cardiorespiratory fitness according to showering behaviours and examined predictors of showering. We measured PA and cardiorespiratory fitness of n = 3921 pupils (11-16 years, 53.5% males) from eight high schools. Pupils self-reported showering behaviour and parental PA levels. We calculated deprivation and distance travelled to school from their home postcode. Overall, 53% of boys and 68% of girls said they never shower after PE. Pupils who did not shower after PE were less physically active and engaged in fewer team sports. Girls who did not shower also had lower cardiorespiratory fitness than those who did. Showering behaviour varied greatly by school, so we adjusted for clustering at the school level. Pupils were more likely to shower if they were active with their parents [odds ratio (OR) = 1.72; 95% CI: 1.43, 2.07] and less likely to shower if they were from deprived areas (OR = 0.68; 95% CI: 0.52, 0.88). Showering after PE is relatively rare in English schoolchildren, particularly girls. While we cannot infer causality regarding the relationships found here, the low rates of showering and the lower PA and cardiorespiratory fitness (in girls) observed in schoolchildren who do not shower suggest research is needed to determine whether showering is a barrier to being physically active during PE.

  15. Detection of airborne Legionella while showering using liquid impingement and fluorescent in situ hybridization (FISH).

    PubMed

    Deloge-Abarkan, Magali; Ha, Thi-Lan; Robine, Enric; Zmirou-Navier, Denis; Mathieu, Laurence

    2007-01-01

    Aerosols of water contaminated with Legionella bacteria constitute the only mode of exposure for humans. However, the prevention strategy against this pathogenic bacteria risk is managed through the survey of water contamination. No relationship linked the Legionella bacteria water concentration and their airborne abundance. Therefore, new approaches in the field of the metrological aspects of Legionella bioaerosols are required. This study was aimed at testing the main principles for bioaerosol collection (solid impaction, liquid impingement and filtration) and the in situ hybridization (FISH) method, both in laboratory and field assays, with the intention of applying such methodologies for airborne Legionella bacteria detection while showering. An aerosolization chamber was developed to generate controlled and reproducible L. pneumophila aerosols. This tool allowed the identification of the liquid impingement method as the most appropriate one for collecting airborne Legionella bacteria. The culturable fraction of airborne L. pneumophila recovered with the liquid impingement principle was 4 and 700 times higher compared to the impaction and filtration techniques, respectively. Moreover, the concentrations of airborne L. pneumophila in the impinger fluid were on average 7.0 x 10(5) FISH-cells m(-3) air with the fluorescent in situ hybridization (FISH) method versus 9.0 x 10(4) CFU m(-3) air with the culture method. These results, recorded under well-controlled conditions, were confirmed during the field experiments performed on aerosols generated by hot water showers in health institutions. This new approach may provide a more accurate characterization of aerobiocontamination by Legionella bacteria.

  16. Effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco.

    PubMed

    Makan, Abdelhadi; Assobhei, Omar; Mountadar, Mohammed

    2013-01-03

    This study aimed to evaluate the effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco in terms of internal temperature, produced gases quantity, organic matter conversion rate, and the quality of the final composts.For this purpose, in-vessel bioreactor was designed and used to evaluate both appropriate initial air pressure and appropriate initial moisture content for the composting process. Moreover, 5 experiments were carried out within initial moisture content of 55%, 65%, 70%, 75% and 85%. The initial air pressure and the initial moisture content of the mixture showed a significant effect on the aerobic composting. The experimental results demonstrated that for composting organic waste, relatively high moisture contents are better at achieving higher temperatures and retaining them for longer times.This study suggested that an initial moisture content of around 75%, under 0.6 bar, can be considered as being suitable for efficient composting of organic fraction of municipal solid waste. These last conditions, allowed maximum value of temperature and final composting product with good physicochemical properties as well as higher organic matter degradation and higher gas production. Moreover, final compost obtained showed good maturity levels and can be used for agricultural applications.

  17. Prevention of intraoperative wound contamination with chlorhexidine shower and scrub.

    PubMed

    Garibaldi, R A

    1988-04-01

    In a prospective, controlled, clinical trial, we found that preoperative showering and scrubbing with 4% chlorhexidine gluconate was more effective than povidone-iodine or triclocarban medicated soap in reducing skin colonization at the site of surgical incision. Mean log colony counts of the incision site were one half to one log lower for patients who showered with chlorhexidine compared to those who showered with the other regimens. No growth was observed on 43% of the post shower skin cultures from patients in the chlorhexidine group compared with 16% of the cultures from patients who had povidone-iodine showers and 5% of those from patients who used medicated soap and water. The frequency of positive intraoperative wound cultures was 4% with chlorhexidine, 9% with povidone-iodine and 14% with medicated soap and water. This study demonstrates that chlorhexidine gluconate is a more effective skin disinfectant than either povidone-iodine or triclocarban soap and water and that its use is associated with lower rates of intraoperative wound contamination.

  18. Alternative energy estimation from the shower lateral distribution function

    NASA Astrophysics Data System (ADS)

    de Souza, Vitor; Escobar, Carlos; Brito, Joel; Dobrigkeit, Carola; Medina-Tanco, Gustavo

    The surface detector technique has been successfully used to detect cosmic ray showers for several decades. Scintillators or Cerenkov water tanks can be used to measure the number of particles and/or the energy density at a given depth in the atmosphere and reconstruct the primary particle properties. It has been shown that the experiment configuration and the resolution in reconstructing the core position determine a distance to the shower axis in which the lateral distribution function (LDF) of particles shows the least variation with respect to different primary particles type, simulation models and specific shapes of the LDF. Therefore, the signal at this distance (600 m for Haverah Park and 1000 m for Auger Observatory) has shown to be a good estimator of the shower energy. Revisiting the above technique, we show that a range of distances to the shower axis, instead of one single point, can be used as estimator of the shower energy. A comparison is done for the Auger Observatory configuration and the new estimator proposed here is shown to be a good and robust alternative to the standard single point procedure.

  19. Comparative analysis of showering protocols for mass-casualty decontamination.

    PubMed

    Amlot, Richard; Larner, Joanne; Matar, Hazem; Jones, David R; Carter, Holly; Turner, Elizabeth A; Price, Shirley C; Chilcott, Robert P

    2010-01-01

    A well-established provision for mass-casualty decontamination that incorporates the use of mobile showering units has been developed in the UK. The effectiveness of such decontamination procedures will be critical in minimizing or preventing the contamination of emergency responders and hospital infrastructure. The purpose of this study was to evaluate three empirical strategies designed to optimize existing decontamination procedures: (1) instructions in the form of a pictorial aid prior to decontamination; (2) provision of a washcloth within the showering facility; and (3) an extended showering period. The study was a three-factor, between-participants (or "independent") design with 90 volunteers. The three factors each had two levels: use of washcloths (washcloth/no washcloth), washing instructions (instructions/no instructions), and shower cycle duration (three minutes/six minutes). The effectiveness of these strategies was quantified by whole-body fluorescence imaging following application of a red fluorophore to multiple, discrete areas of the skin. All five showering procedures were relatively effective in removing the fluorophore "contaminant", but the use of a cloth (in the absence of instructions) led to a significant ( appox. 20%) improvement in the effectiveness of decontamination over the standard protocol (p <0.05). Current mass-casualty decontamination effectiveness, especially in children, can be optimized by the provision of a washcloth. This simple but effective approach indicates the value of performing controlled volunteer trials for optimizing existing decontamination procedures.

  20. The activity of autumn meteor showers in 2006-2008

    NASA Astrophysics Data System (ADS)

    Kartashova, Anna

    2015-03-01

    The purpose of meteor observations in INASAN is the study of meteor showers, as the elements of the migrant substance of the Solar System, and estimation of risk of hazardous collisions of spacecrafts with the particles of streams. Therefore we need to analyze the meteor events with brightness of up to 8 m, which stay in meteoroid streams for a long time and can be a hazardous for the spacecraft. The results of our single station TV observations of autumn meteor showers for the period from 2006 to 2008 are presented. The high-sensitive hybrid camera (the system with coupled of the Image Intensifier) FAVOR with limiting magnitude for meteors about 9m. . .10m in the field of view 20 × 18 was used for observations. In 2006-2008 from October to November more than 3 thousand of meteors were detected, 65% from them have the brightness from 6m to 9m. The identification with autumn meteor showers (Orionids, Taurids, Draconids, Leonids) was carried out. In order to estimate the density of the influx of meteor matter to the Earth for these meteor showers the Index of meteor activity (IMA) was calculated. The IMA distribution for the period 2006 - 2008 is given. The distributions of autumn meteor showers (the meteors with brightness of up to 8 m) by stellar magnitude from 2006 to 2008 are also presented.

  1. Leonid Shower Probe of Aerothermochemistry in Meteoric Plasmas and Implication for the Origin of Life

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter S. I.; Packan, D.; Laux, C.; Wilson, Mike; Boyd, I. D.; Kruger, C. H.; Popova, O.; Fonda, M.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The rarefied and high Mach number (up to 270) of the flow field of a typical meteoroid as it enters the Earth's atmosphere implies conditions of ablation and atmospheric chemistry that have proven to be as difficult to grasp as the proverbial shooting star. An airborne campaign was organized to study these processes during an intense Leonid shower. A probe of molecular band emission now demonstrates that the flash of light from a common meteor originates in the wake of the object rather than in the meteor head. A new theoretical approach using the direct simulation Monte Carlo technique demonstrates that the ablation process is critical in heating the air in that wake. Air molecules impinge on a dense cloud of ablated material in front of the meteoroid head into an extended wake that has the observed excitation temperatures. These processes determine what extraterrestrial materials may have been delivered to Earth at the time of the origin of life.

  2. Comet showers as a cause of mass extinction

    NASA Technical Reports Server (NTRS)

    Hut, Piet; Alvarez, Walter; Elder, William P.; Kauffman, Erle G.; Hansen, Thor; Keller, Gerta; Shoemaker, Eugene M.; Weissman, Paul R.

    1987-01-01

    Three independent pieces of evidence supporting a connection between comet showers and clustering in terrestrial cratering and mass extinctions are presented. The temporal profile of a comet shower triggered by a star passing through the Oort cloud is calculated. Four weak peaks are found in the age of distribution of impact craters over the past 100 Myr, as well as two compact clusters of ages of impact glass broadly coincident with crater-age peaks. Recent paleontological observations are reviewed that indicate a stepwise character for some well-documented mass extinctions in the past 100 Myr which roughly coincide with three of the four peaks in crater ages and which have a duration compatible with comet shower predictions.

  3. SUMMARY OF THE 2006 HADRONIC SHOWER SIMULATION WORKSHOP

    SciTech Connect

    WATERS, LAURIE S.

    2007-01-19

    The 2006 Hadronic Shower Simulation Workshop, held September 6-8, 2006 at Fermi National Laboratory brought together an international assembly of experts in the field of hadronic shower development. The overall goal was to present the current understanding of the physics of hadronic showers, and to study examples of how this is measured in particle-physics calorimetry. The modeling of such events is critical, and the major Monte Carlo codes, FLUKA, GEANT, MARS, MCNPX, and PHTS were represented at the workshop. A wide range of physics, much of which is used by the simulation codes was also discussed, ranging from the hadronic CEM, LAQGSM, and DTUJET models, down to low energy neutronics capabilities. Special purpose codes and methodologies used for specific applications such as muon and neutrino physics were also shown. The results of a code benchmarking exercises were presented and extensively discussed. This paper summarizes the key topics presented in the workshop.

  4. Longitudinal shower development and its signature at observation level

    NASA Astrophysics Data System (ADS)

    Chitnis, V. R.; Bhat, P. N.

    2002-03-01

    From a study of Cverenkov photon arrival times at various core distances at the observation level it has already been established that the photon front is well fitted with a spherical surface traveling at the speed of light and originating from a fixed point on the shower axis. The radius of curvature as measured at the observation level has been found to be roughly equal to the height of shower maximum from the observation level. In the present work we study the relationship between the radius of curvature of the shower fromt (R), the height of electron maximum (he), the Cverenkov photon maximum (hCv) and the average production height of Cverenkov photons (h-). Cverenkov pulse width (w) has always ben used as a parameter to study cascade development especially at tens of PeV energies. We discuss the relation between the w and he at TeV energies for gamma-ray and proton primaries.

  5. INITIAL FEASIBILITY STUDY FOR EXPLORATION OF THREE U.S. AIR FORCE COURSE MATERIALS FOR ADAPTATION TO CIVILIAN SCHOOL SYSTEMS. FINAL REPORT.

    ERIC Educational Resources Information Center

    STRAUBEL, JAMES H.; AND OTHERS

    THE OBJECTIVE OF THIS STUDY WAS TO MAKE AN INITIAL DETERMINATION OF THE FEASIBILITY OF ADAPTING, IMPLEMENTING, AND EVALUATING WITHIN THE UTAH EDUCATIONAL SYSTEM THREE AIR FORCE COURSES--ELECTRONICS PRINCIPLES, MEDICAL SERVICE SPECIALIST COURSE, AND AIRCRAFT MECHANICS. THE FIRST PHASE OF THE STUDY WAS CONCERNED WITH ESTABLISHING CRITERIA AGAINST…

  6. Aging comets and their meteor showers

    NASA Astrophysics Data System (ADS)

    Ye, Quan-Zhi

    2016-10-01

    Comets are thought to be responsible for the terrestrial accretion of water and organic materials. The aging of comets is one of the most critical yet poorly understood problems in planetary astronomy. Here we attack this problem by examining different parts of the cometary aging spectrum of Jupiter-family comets (JFCs), a group of comets that dominates the cometary influx in the near-Earth space, using both telescopic and meteor observations.We examine two representative JFCs and the population of dormant comets. At the younger end of the aging spectrum, we examine a moderately active JFC, 15P/Finlay, and review the puzzle of the non-detection of the associated Finlayid meteor shower. We find that, although having been behaved like a dying comet in the past several 102 years, 15P/Finlay does possess ability for energetic outbursts without a clear reason. Towards the more aged end of the spectrum, we examine a weakly active JFC, 209P/LINEAR. By bridging telescopic observations at visible and infrared wavelength, meteor observations and dynamical investigations, we find that 209P/LINEAR is indeed likely an aged yet long-lived comet. At the other end of the spectrum, we examine the population of dormant near-Earth comets, by conducting a comprehensive meteor-based survey looking for dormant comets that have recently been active. We find the lower limit of the dormant comet fraction in the near-Earth object (NEO) population to be 2.0 ± 1.7%. This number is at the lower end of the numbers found using dynamical and telescopic techniques, which may imply that a significant fraction of comets in the true JFC population are weakly active and are not yet detected.These results have revealed interesting diversities in dying or dead comets, both in their behaviors as well as their natures. An immediate quest in the understanding of cometary aging would be to examine a large number of dying or dead comets and understand their general characteristics.

  7. Renovation of Waste Shower Water by Membrane Filtration.

    DTIC Science & Technology

    1976-11-01

    Formulation of Synthetic Shower Wastewater Item Quantity mg/I g/ 180 gal g/7000 gal Soap 33 22.5 875 NaCl 40 27.1 1054 U ret! 0.5 0.33 12.8 Kaolin 9.1...6.21 242 Talc 9.4 6.42 250 Shower Cleaner 48 32.6 1268 Hair 4.8 3.3 128 Hair Oil 75 51 1983 Hair Gel 18 12.1 471 Shampoo 2.4 1.64 64 Toothpaste 18

  8. Test results on reuse of reclaimed shower water - A summary

    NASA Technical Reports Server (NTRS)

    Verostko, Charles E.; Garcia, Rafael; Sauer, Richard; Reysa, Richard P.; Linton, Arthur T.

    1989-01-01

    Results are presented from tests to evaluate a microgravity whole body shower and waste water recovery system design for possible use on the Space Station. Several water recovery methods were tested, including phase change distillation, a thermoelectric hollow fiber membrane evaporation subsystem, and a reverse osmosis dynamic membrane system. Consideration is given to the test hardware, the types of soaps evaluated, the human response to showering with reclaimed water, chemical treatment for microbial control, the procedures for providing hygienic water, and the quality of water produced by the systems. All three of the waste water recovery systems tested successfully produced reclaimed water for reuse.

  9. Relationship between Air Traffic Selection and Training (AT-SAT)) Battery Test Scores and Composite Scores in the Initial en Route Air Traffic Control Qualification Training Course at the Federal Aviation Administration (FAA) Academy

    ERIC Educational Resources Information Center

    Kelley, Ronald Scott

    2012-01-01

    Scope and Method of Study: This study focused on the development and use of the AT-SAT test battery and the Initial En Route Qualification training course for the selection, training, and evaluation of air traffic controller candidates. The Pearson product moment correlation coefficient was used to measure the linear relationship between the…

  10. Ambient Air Pollution and Neurotoxicity on Brain Structure: Evidence from Women’s Health Initiative Memory Study

    PubMed Central

    Chen, Jiu-Chiuan; Wang, Xinhui; Wellenius, Gregory A.; Serre, Marc L.; Driscoll, Ira; Casanova, Ramon; McArdle, John J.; Manson, JoAnn E.; Chui, Helena C.; Espeland, Mark A.

    2015-01-01

    Objective To examine the putative adverse effects of ambient fine particulate matter (PM2.5) on brain volumes in older women. Methods We conducted a prospective study of 1403 community-dwelling older women without dementia enrolled in the Women's Health Initiative Memory Study (WHIMS), 1996–8. Structural brain MRI scans were performed at age of 71–89 years in 2005–6 to obtain volumetric measures of gray matter (GM) and normal-appearing white matter (WM). Given residential histories and air monitoring data, we used a spatiotemporal model to estimate cumulative PM2.5 exposure in 1999–2006. Multiple linear regression was employed to evaluate the associations between PM2.5 and brain volumes, adjusting for intracranial volumes and potential confounders. Results Older women with greater PM2.5 exposures had significantly smaller WM, but not GM volumes, independent of geographic region, demographics, socioeconomic status, lifestyles, and clinical characteristics including cardiovascular risk factors. For each inter-quartile increment (3.49 µg/m3) of cumulative PM2.5 exposure, the average WM volume (95% confidence interval) was 6.23 (3.72–8.74) cm3 in the total brain and 4.47 (2.27–6.67) cm3 lower in the association areas, equivalent to 1–2 years of brain aging. The adverse PM2.5 effects on smaller WM volumes were present in frontal and temporal lobes and corpus callosum (all p-values <0.01). Hippocampal volumes did not differ by PM2.5 exposure. Interpretation PM2.5 exposure may contribute to WM loss in older women. Future studies are needed to determine whether exposures result in myelination disturbance, disruption of axonal integrity, damages to oligodendrocytes, or other WM neuropathologies. PMID:26075655

  11. Non-Chemical Stressors and Cumulative Risk Assessment: An Overview of Current Initiatives and Potential Air Pollutant Interactions

    PubMed Central

    Lewis, Ari S.; Sax, Sonja N.; Wason, Susan C.; Campleman, Sharan L.

    2011-01-01

    Regulatory agencies are under increased pressure to consider broader public health concerns that extend to multiple pollutant exposures, multiple exposure pathways, and vulnerable populations. Specifically, cumulative risk assessment initiatives have stressed the importance of considering both chemical and non-chemical stressors, such as socioeconomic status (SES) and related psychosocial stress, in evaluating health risks. The integration of non-chemical stressors into a cumulative risk assessment framework has been largely driven by evidence of health disparities across different segments of society that may also bear a disproportionate risk from chemical exposures. This review will discuss current efforts to advance the field of cumulative risk assessment, highlighting some of the major challenges, discussed within the construct of the traditional risk assessment paradigm. Additionally, we present a summary of studies of potential interactions between social stressors and air pollutants on health as an example of current research that supports the incorporation of non-chemical stressors into risk assessment. The results from these studies, while suggestive of possible interactions, are mixed and hindered by inconsistent application of social stress indicators. Overall, while there have been significant advances, further developments across all of the risk assessment stages (i.e., hazard identification, exposure assessment, dose-response, and risk characterization) are necessary to provide a scientific basis for regulatory actions and effective community interventions, particularly when considering non-chemical stressors. A better understanding of the biological underpinnings of social stress on disease and implications for chemical-based dose-response relationships is needed. Furthermore, when considering non-chemical stressors, an appropriate metric, or series of metrics, for risk characterization is also needed. Cumulative risk assessment research will benefit

  12. Non-chemical stressors and cumulative risk assessment: an overview of current initiatives and potential air pollutant interactions.

    PubMed

    Lewis, Ari S; Sax, Sonja N; Wason, Susan C; Campleman, Sharan L

    2011-06-01

    Regulatory agencies are under increased pressure to consider broader public health concerns that extend to multiple pollutant exposures, multiple exposure pathways, and vulnerable populations. Specifically, cumulative risk assessment initiatives have stressed the importance of considering both chemical and non-chemical stressors, such as socioeconomic status (SES) and related psychosocial stress, in evaluating health risks. The integration of non-chemical stressors into a cumulative risk assessment framework has been largely driven by evidence of health disparities across different segments of society that may also bear a disproportionate risk from chemical exposures. This review will discuss current efforts to advance the field of cumulative risk assessment, highlighting some of the major challenges, discussed within the construct of the traditional risk assessment paradigm. Additionally, we present a summary of studies of potential interactions between social stressors and air pollutants on health as an example of current research that supports the incorporation of non-chemical stressors into risk assessment. The results from these studies, while suggestive of possible interactions, are mixed and hindered by inconsistent application of social stress indicators. Overall, while there have been significant advances, further developments across all of the risk assessment stages (i.e., hazard identification, exposure assessment, dose-response, and risk characterization) are necessary to provide a scientific basis for regulatory actions and effective community interventions, particularly when considering non-chemical stressors. A better understanding of the biological underpinnings of social stress on disease and implications for chemical-based dose-response relationships is needed. Furthermore, when considering non-chemical stressors, an appropriate metric, or series of metrics, for risk characterization is also needed. Cumulative risk assessment research will benefit

  13. Spallation backgrounds in Super-Kamiokande are made in muon-induced showers

    NASA Astrophysics Data System (ADS)

    Li, Shirley Weishi; Beacom, John F.

    2015-05-01

    Crucial questions about solar and supernova neutrinos remain unanswered. Super-Kamiokande has the exposure needed for progress, but detector backgrounds are a limiting factor. A leading component is the beta decays of isotopes produced by cosmic-ray muons and their secondaries, which initiate nuclear spallation reactions. Cuts of events after and surrounding muon tracks reduce this spallation decay background by ≃ 90 % (at a cost of ≃ 20 % deadtime), but its rate at 6-18 MeV is still dominant. A better way to cut this background was suggested in a Super-Kamiokande paper by Bays et al. [Phys. Rev. D 85, 052007 (2012)] on a search for the diffuse supernova neutrino background. They found that spallation decays above 16 MeV were preceded near the same location by a peak in the apparent Cherenkov light profile from the muon; a more aggressive cut was applied to a limited section of the muon track, leading to decreased background without increased deadtime. We put their empirical discovery on a firm theoretical foundation. We show that almost all spallation decay isotopes are produced by muon-induced showers and that these showers are rare enough and energetic enough to be identifiable. This is the first such demonstration for any detector. We detail how the physics of showers explains the peak in the muon Cherenkov light profile and other Super-K observations. Our results provide a physical basis for practical improvements in background rejection that will benefit multiple studies. For solar neutrinos, in particular, it should be possible to dramatically reduce backgrounds at energies as low as 6 MeV.

  14. Using NLDAS-2 for initializing integrated watershed models: Model spin-up for the AirMOSS Campaign

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS) investigation has been developed for high-resolution in time and space root-zone soil moisture and carbon estimation. AirMOSS will build an ultra-high frequency (UHF) synthetic aperture radar (SAR) that has the capability to penetr...

  15. 77 FR 14006 - Record of Decision for the Military Housing Privatization Initiative Hurlburt Field and Eglin Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-08

    ... Availability (NOA) of a Record of Decision (ROD). SUMMARY: On February 6, 2012, the United States Air Force... to the public on June 24, 2011 through a NOA in the Federal Register (Volume 76, Number 122, Page... Force with respect to the proposed Air Force actions analyzed in the FEIS. Authority: This NOA...

  16. Applicability of a ``shower`` passive cooling tower in a hot dry climate

    SciTech Connect

    Givoni, B.; Al-Hemiddi, N.

    1995-11-01

    This cooling system has originally been developed by Givoni for cooling outdoor rest areas for the EXPO`92 in Seville, Spain. However, it can also be applied, and has been tested, as a cooling system for building and enclosed and shaded courtyards. It consists of an open shaft with showers at the top and a collecting ``pond`` at the bottom. Water is recirculated by a pump. The falling water entrain a large volume of air, creating a flow of cooled air down the shaft and into a building. A wind catcher can be installed above the shaft to enhance the air flow rate. The paper presents data on the performance of the system, tested by Al Hemiddi, including experimental data obtained first in a ``patio`` test cell at UCLA in Los Angeles, and later in a full size room in Riyadh, Saudi Arabia. The testing in Riyadh has demonstrated that with outdoor air maximum temperature of about 45 C the indoor air maximum of the cooled room was bout 29 C. This system can use brackish and sea water, in addition to fresh water. Thus it is applicable and capable of providing indoor comfort even in very hot desert regions, where any kind of water, even sea water, is available.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  18. Clustering of Hadronic Showers with a Structural Algorithm

    SciTech Connect

    Charles, M.J.; /SLAC

    2005-12-13

    The internal structure of hadronic showers can be resolved in a high-granularity calorimeter. This structure is described in terms of simple components and an algorithm for reconstruction of hadronic clusters using these components is presented. Results from applying this algorithm to simulated hadronic Z-pole events in the SiD concept are discussed.

  19. Visual data of minor meteor showers limits of the method

    NASA Technical Reports Server (NTRS)

    Rendtel, Jurgen; Koschack, R.

    1992-01-01

    Visual meteor observations are carried out on a regular basis by many experienced observers worldwide, thus supplying information about activity of meteor showers. The limits of the method are determined by the accuracy of the detection of the meteor trail. This study shows that visual meteor observations provide reliable data for an observable hourly rate of greater than or equal to 3.

  20. A (revised) confidence index for the forecasting of meteor showers

    NASA Astrophysics Data System (ADS)

    Vaubaillon, J.

    2016-01-01

    A confidence index for the forecasting of meteor showers is presented. The goal is to provide users with information regarding the way the forecasting is performed, so several degrees of confidence is achieved. This paper presents the meaning of the index coding system.

  1. Large Deviation Analysis of Rapid Onset of Rain Showers

    NASA Astrophysics Data System (ADS)

    Wilkinson, Michael

    2016-01-01

    Rainfall from ice-free cumulus clouds requires collisions of large numbers of microscopic droplets to create every raindrop. The onset of rain showers can be surprisingly rapid, much faster than the mean time required for a single collision. Large-deviation theory is used to explain this observation.

  2. Simulating Meteor Shower Observations In The Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    McAuliffe, J. P.; Christou, A. A.

    2005-08-01

    It is known that fast meteoroids entering the martian atmosphere give rise to bright, detectable meteors (Adolfsson et al, Icarus 119, 144, 1996). Although single meteors have already been detected at Mars (Selsis et al., Nature 435, 581, 2005), the characterisation of the martian meteor year will require a large number of detections. Experience at the Earth suggests that data storage and bandwidth resources to conduct such surveys will be substantial, and may be prohibitive. In an attempt to quantify the problem in detail, we have simulated meteor shower detection in the martian and terrestrial atmospheres. For a given shower, we assume a meteoroid stream flux, size distribution and velocity based on current knowledge of Earth streams as well as the proximity of certain comets' orbits to that of Mars. A numerical code is used to simulate meteoroid ablation in a model martian and terrestrial atmosphere. Finally, using the same baseline detector characteristics (limiting magnitude, sky coverage) we generate detection statistics for the two planets. We will present results for different types of showers, including strong annual activity and episodic outbursts from Halley-type and Jupiter family comets. We will show how detection efficiency at Mars compares to the Earth for these showers and discuss optimum strategies for monitoring the martian atmosphere for meteor activity. Astronomy research at Armagh Observatory is funded by the Northern Ireland Department of Culture, Arts and Leisure (DCAL).

  3. Don Quixote --- a possible parent body of a meteor shower

    NASA Astrophysics Data System (ADS)

    Rudawska, R.; Vaubaillon, J.

    2014-07-01

    This talk addresses the topic of meteoroid stream parent body in relation to meteor showers observed on the Earth. We carry out a further search to investigate the possibility of meteor shower observations caused by particles ejected from (3552) Don Quixote. The (3552) Don Quixote asteroid was discovered in 1983 as an Amor asteroid. The Tisserand parameter for the orbit has a value of 2.315 with respect to Jupiter, which indicates a comet-like orbit. The diameter of the object calculated from the absolute magnitude, is in the range of 12.3--24.5 km. It all makes Don Quixote a good candidate for a short-period comet among known near-Earth objects, which the recently observed cometary activity confirms [1]. We have investigated the orbital evolution of the meteoroid stream originated from Don Quixote. If the object was active in the past, it might be a parent body for a meteor shower observed on the Earth. The model for the generation and evolution of the meteoroid stream in the Solar System is taken from [2]. The asteroid's orbital elements and physical properties are taken from the JPL horizons website. The ejections of meteoroids from the asteroid surface took place when the asteroid was passing its perihelion between 5000 B.C. and 2013 A.D. Next, the orbits of ejected meteoroids were integrated to the year 2050. If a meteoroid is sufficiently close to the Earth, its orbital parameters are saved and compared with known showers.

  4. BATH 1 SHOWING THE SHOWER ENCLOSURE AND FLUSH DOOR OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BATH 1 SHOWING THE SHOWER ENCLOSURE AND FLUSH DOOR OF LINEN CLOSET. VIEW FACING SOUTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Three-Bedroom Duplex Type 4, Acacia Road, Birch Circle, Cedar Drive and Elm Drive, Pearl City, Honolulu County, HI

  5. Ports Initiative

    EPA Pesticide Factsheets

    The purpose of the ports initiative is to assist EPA and other participants to formulate strategies for moving forward on actions addressing the transportation, air quality and climate issues raised in the National Conversations.

  6. Measure Guideline: Water Management at Tub and Shower Assemblies

    SciTech Connect

    Dickson, B.

    2011-12-01

    Due to the high concentrations of water and the consequential risk of water damage to the home's structure a comprehensive water management system is imperative to protect the building assemblies underlying the finish surround of tub and shower areas. This guide shows how to install fundamental waterproofing strategies to prevent water related issues at shower and tub areas. When conducting a total gut rehab of a structure or constructing a new home, best practice installation and detailing for effective waterproofing are critically important at bathtub and shower assemblies. Water management issues in a structure may go unrecognized for long periods, so that when they are finally observed, the damage from long-term water exposure is extensive. A gut rehab is often undertaken when a home has experienced a natural disaster or when the homeowners are interested in converting an old, high-energy-use building into a high-quality, efficient structure that meets or exceeds one of the national energy standards, such as ENERGY STAR or LEED for homes. During a gut rehab, bath areas need to be replaced with diligent attention to detail. Employing effective water management practices in the installation and detailing of tub and shower assemblies will minimize or eliminate water issues within the building cavities and on the finished surfaces. A residential tub-and-shower surround or shower-stall assembly is designed to handle a high volume of water - 2.5 gallons per minute, with multiple baths occurring during a typical day. Transitions between dissimilar materials and connections between multiple planes must be installed with care to avoid creating a pathway for water to enter the building assemblies. Due to the high volume of water and the consequential risk of water damage to the home's structure, a comprehensive water management system is imperative to protect the building assemblies underlying the finish surround of tub and shower areas. At each stage of construction

  7. Application of thermoluminescence for detection of cascade shower 2: Detection of cosmic ray cascade shower at Mount Fuji

    NASA Technical Reports Server (NTRS)

    Akashi, M.; Kawaguchi, S.; Watanabe, Z.; Misaki, A.; Niwa, M.; Okamoto, Y.; Fujinaga, T.; Ichimura, M.; Shibata, T.; Dake, S.

    1985-01-01

    The results of a thermoluminescence (TL) chamber exposed at Mt. Fuji during Aug. '83 - Aug. '84 are reported. The TL signal induced by cosmic ray shower is detected and compared with the spot darkness of X-ray film exposed at the same time.

  8. DOE/NV/26383-LTR2008-01 Letter Report Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Caliente, Lincoln County, Nevada

    SciTech Connect

    J. Engelbrecht; I. Kavouras; D. Campbell; S. Campbell; S. Kohl; D. Shafer

    2009-04-02

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Beatty, Sarcobatus Flats, Rachel, Caliente, Pahranagat NWR, Crater Flat, and Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data, on completion of the site's sampling program.

  9. Initial Field Trials of the Site Characterization and Analysis Penetrometer System (SCAPS). Reconnaissance of Jacksonville Naval Air Station Waste Oil and Solvents Disposal Site

    DTIC Science & Technology

    1993-12-01

    Engineers Waterways Experiment Station DTIC Initial Field Trials of the Site ELECTF Characterization and Analysis JAN2 5 1994D Penetrometer System...038Prepared f NlFclitie 24En g m Prepared for Naval Facilities Engineering Command The contents of this report are not to be used for advertising. publication...Characterization and Analysis Penetrometer Sysstem (SCAPS) Reconnaissance of Jacksonville Naval Air Station Waste Oil and Solvents Disposal Site by Stafford S

  10. An Analysis of Current Attitudes of Company Grade and Field Grade Air Force Officers Regarding Air Force Officer Professional Development Initiatives

    DTIC Science & Technology

    1989-09-01

    officer. Captains John J. Beishke Jr. and James R. Lipsey researched the career backgrounds of Ai Force generals and colonels passed over for promotion and...experience than colonels who had been passed over for promotion (Beishke and Lipsey , 1977:4,84). This thesis, because of its careeristic approach to rank...and James R. Lipsey . Career Progression ,:o General Officer in the United States Air Force. MS Thesis, AFIT/LSSR 4-77B. School of Systems and

  11. First results from the spectral DCT trigger implemented in the Cyclone V Front-End Board used for a detection of very inclined showers in the Pierre Auger surface detector Engineering Array

    SciTech Connect

    Szadkowski, Zbigniew

    2015-07-01

    The paper presents the first results from the trigger based on the Discrete Cosine Transform (DCT) operating in the new Front-End Boards with Cyclone V FPGA deployed in 8 test surface detectors in the Pierre Auger Engineering Array. The patterns of the ADC traces generated by very inclined showers were obtained from the Auger database and from the CORSIKA simulation package supported next by Offline reconstruction Auger platform which gives a predicted digitized signal profiles. Simulations for many variants of the initial angle of shower, initialization depth in the atmosphere, type of particle and its initial energy gave a boundary of the DCT coefficients used next for the on-line pattern recognition in the FPGA. Preliminary results have proven a right approach. We registered several showers triggered by the DCT for 120 MSps and 160 MSps. (authors)

  12. Air quality modelling using the Met Office Unified Model (AQUM OS24-26): model description and initial evaluation

    NASA Astrophysics Data System (ADS)

    Savage, N. H.; Agnew, P.; Davis, L. S.; Ordóñez, C.; Thorpe, R.; Johnson, C. E.; O'Connor, F. M.; Dalvi, M.

    2013-03-01

    The on-line air quality model AQUM (Air Quality in the Unified Model) is a limited-area forecast configuration of the Met Office Unified Model which uses the UKCA (UK Chemistry and Aerosols) sub-model. AQUM has been developed with two aims: as an operational system to deliver regional air quality forecasts and as a modelling system to conduct air quality studies to inform policy decisions on emissions controls. This paper presents a description of the model and the methods used to evaluate the performance of the forecast system against the automated UK surface network of air quality monitors. Results are presented of evaluation studies conducted for a year-long period of operational forecast trials and several past cases of poor air quality episodes. The results demonstrate that AQUM tends to over-predict ozone (~8 μg m-3 mean bias for the year-long forecast), but has a good level of responsiveness to elevated ozone episode conditions - a characteristic which is essential for forecasting poor air quality episodes. AQUM is shown to have a negative bias for PM10, while for PM2.5 the negative bias is much smaller in magnitude. An analysis of speciated PM2.5 data during an episode of elevated particulate matter (PM) suggests that the PM bias occurs mainly in the coarse component. The sensitivity of model predictions to lateral boundary conditions (LBCs) has been assessed by using LBCs from two different global reanalyses and by comparing the standard, single-nested configuration with a configuration having an intermediate European nest. We conclude that, even with a much larger regional domain, the LBCs remain an important source of model error for relatively long-lived pollutants such as ozone. To place the model performance in context we compare AQUM ozone forecasts with those of another forecasting system, the MACC (Monitoring Atmospheric Composition and Climate) ensemble, for a 5-month period. An analysis of the variation of model skill with forecast lead time is

  13. Air Quality Model Evaluation International Initiative (AQMEII): Advancing State of the Science in Regional Photochemical Modeling and Its Applications

    EPA Science Inventory

    Although the focus in the 1970s was primarily on urban air pollution models, it is well known that pollution problems such as acid rain, ozone, and fine particulate matter are regional in scope, requiring regional-scale multipollutant models. In North America and Europe, several ...

  14. Containment and resolution of hadronic showers at the FCC

    NASA Astrophysics Data System (ADS)

    Carli, T.; Helsens, C.; Henriques Correia, A.; Solans Sánchez, C.

    2016-09-01

    The particles produced at a potential Future Circular Collider with √s = 100 TeV are of unprecented energies. In this document we present the hadronic shower containment and resolution parametrizations based on Geant4 simulations for the Hadronic calorimetry needed for conceptual detector design at this energy. The Geant4 toolkit along with FTFP_BERT physics list are used in this study. Comparisons are made with test-beam data from the ATLAS Tile hadronic calorimeter. These simulations motivate a 12 λ calorimeter in order to contain at 98% level TeV single hadron showers and multi-TeV jets and keep a pion energy resolution constant term of approximately 3%.

  15. Frequency and intensity of comet showers from the Oort cloud

    SciTech Connect

    Heisler, J.; Alcock, C.; Tremaine, S.

    1987-05-01

    The nature of new comets and the frequency and intensity of comet showers are presently studied by means of a simulation in which an ensemble of one million comets is perturbed at random times by the Bahcall-Soneira (1980) Galaxy model's population of main sequence stars and white dwarfs. The time-integrated flux is dominated by the showers for comets whose semimajor axes are less than about 30,000 AU. The inclusion of tidal effects increases the loss rate of comets with semimajor axes between 10,000 and 20,000 AU by a factor of about 4, so that the Galactic tide, rather than individual stellar perturbations, is the dominant Oort cloud evolution-driving mechanism. 44 references.

  16. Signal fluctuations and multi-layer shower fronts

    SciTech Connect

    Morales, B.; Nellen, L.

    2009-04-20

    The time resolution of the FADC traces of the Auger SD allows us to explore details of the signal shape. An example is that we can easily identify muons like pulses that stand out in the signals. With further exploration it is possible to find other systematic structures and explore the physics involved. We analyze the occurrence of these structures as fluctuations and evaluate how these structures can be connected to the shower development in the atmosphere.

  17. Scaling and design analyses of a scaled-down, high-temperature test facility for experimental investigation of the initial stages of a VHTR air-ingress accident

    SciTech Connect

    Arcilesi, David J.; Ham, Tae Kyu; Kim, In Hun; Sun, Xiaodong; Christensen, Richard N.; Oh, Chang H.

    2015-07-01

    A critical event in the safety analysis of the very high-temperature gas-cooled reactor (VHTR) is an air-ingress accident. This accident is initiated, in its worst case scenario, by a double-ended guillotine break of the coaxial cross vessel, which leads to a rapid reactor vessel depressurization. In a VHTR, the reactor vessel is located within a reactor cavity that is filled with air during normal operating conditions. Following the vessel depressurization, the dominant mode of ingress of an air–helium mixture into the reactor vessel will either be molecular diffusion or density-driven stratified flow. The mode of ingress is hypothesized to depend largely on the break conditions of the cross vessel. Since the time scales of these two ingress phenomena differ by orders of magnitude, it is imperative to understand under which conditions each of these mechanisms will dominate in the air ingress process. Computer models have been developed to analyze this type of accident scenario. There are, however, limited experimental data available to understand the phenomenology of the air-ingress accident and to validate these models. Therefore, there is a need to design and construct a scaled-down experimental test facility to simulate the air-ingress accident scenarios and to collect experimental data. The current paper focuses on the analyses performed for the design and operation of a 1/8th geometric scale (by height and diameter), high-temperature test facility. A geometric scaling analysis for the VHTR, a time scale analysis of the air-ingress phenomenon, a transient depressurization analysis of the reactor vessel, a hydraulic similarity analysis of the test facility, a heat transfer characterization of the hot plenum, a power scaling analysis for the reactor system, and a design analysis of the containment vessel are discussed.

  18. Meteor Showers in the Ancient Maya Hieroglyphic Codices

    NASA Astrophysics Data System (ADS)

    Kinsman, J. H.

    2014-07-01

    Researchers of the ancient Maya culture have long been fascinated with the Maya obsession concerning cyclical calendars and precise visual observations of astronomical bodies and phenomena, in particular the Sun, Moon, visible planets, and solar and lunar eclipses. Although considered possible, heretofore no record of specific sightings of comets or meteor showers in the Maya inscriptions has been firmly established by scholars. Besides difficulties with decipherment of the hieroglyphic script, investigators have had to grapple with an ancient Maya calendar that has not been accurately correlated to the European calendar. Recent examination by this researcher has found that it may be possible to recognize written accounts of meteor showers embedded in the hieroglyphic corpus, especially the codices, the screen-fold books that were the tools of the astronomer-priests of that day. By proposing an alternative decipherment of an astronomical sign and using the accompanying hieroglyphic texts and illustrations with appropriate dates, this researcher believes it is possible to demonstrate that the Maya may have recorded meteor showers occurring in the seventh through the tenth centuries AD.

  19. Squark production and decay matched with parton showers at NLO

    NASA Astrophysics Data System (ADS)

    Gavin, R.; Hangst, C.; Krämer, M.; Mühlleitner, M.; Pellen, M.; Popenda, E.; Spira, M.

    2015-01-01

    Extending previous work on the predictions for the production of supersymmetric (SUSY) particles at the LHC, we present the fully differential calculation of the next-to-leading order (NLO) SUSY-QCD corrections to the production of squark and squark-antisquark pairs of the first two generations. The NLO cross sections are combined with the subsequent decay of the final state (anti)squarks into the lightest neutralino and (anti)quark at NLO SUSY-QCD. No assumptions on the squark masses are made, and the various subchannels are taken into account independently. In order to obtain realistic predictions for differential distributions the fixed-order calculations have to be combined with parton showers. Making use of the Powheg method we have implemented our results in the Powheg-Box framework and interfaced the NLO calculation with the parton shower Monte Carlo programs Pythia6 and Herwig++. The code is publicly available and can be downloaded from the Powheg-Box webpage. The impact of the NLO corrections on the differential distributions is studied and parton shower effects are investigated for different benchmark scenarios.

  20. Percutaneous penetration and disposition of triclocarban in man: body showering.

    PubMed

    Scharpf, L G; Hill, I D; Maibach, H I

    1975-01-01

    The percutaneous penetration and metabolic disposition of 14C-3-4,4'-trichlorocarbanilide (triclocarban, TCC) after body showering has been determined in man. Single intravenous doses of trace amounts 14C-triclocarban were given to subjects to determine the pharmacologic disposition of the compound before conducting the shower study. Radioactivity was rapidly cleared from blood after intravenous administrations of 14C-triclocarban in propylene glycol with a blood clearance half-life of 8.6 hours. About 54% of the dose was excreted in the feces and 21% of the dose in the urine with a urinary elimination half-life of ten hours. No radioactivity was detected in the saliva. Subjects took a single shower employing a whole body lather with approximately 7 gm of soap containing 2% 14C-triclocarban on a soap basis. Special blood withdrawal and urinary/fecal collection techniques were utilized that minimized contamination of samples by extraneous 14C-triclocarban. About 0.23% of the applied radioactive dose was recovered in the feces after six days and 0.16% of the dose in the urine after two days. At all sampling times blood levels of radioactivity were below the detection limit of the method (10 part per billion).

  1. Producing EGS4 shower displays with the Unified Graphics System

    SciTech Connect

    Cowan, R.F. . Lab. for Nuclear Science); Nelson, W.R. )

    1990-08-16

    The EGS4 Code System has been coupled with the SLAC Unified Graphics System in such a manner as to provide a means for displaying showers on UGS77-supported devices. This is most easily accomplished by attaching an auxiliary subprogram package (SHOWGRAF) to existing EGS4 User Codes and making use of a graphics display or a post-processor code called EGS4PL. SHOWGRAF may be used to create shower displays directly on interactive IBM 5080 color display devices, supporting three-dimensional rotations, translations, and zoom features, and providing illustration of particle types and energies by color and/or intensity. Alternatively, SHOWGRAF may be used to record a two-dimensional projection of the shower in a device-independent graphics file. The EGS4PL post-processor may then be used to convert this file into device-dependent graphics code for any UGS77-supported device. Options exist within EGS4PL that allow for two-dimensional translations and zoom, for creating line structure to indicate particle types and energies, and for optional display of particles by type. All of this is facilitated by means of the command processor EGS4PL EXEC together with new options (5080 and PDEV) with the standard EGS4IN EXEC routine for running EGS4 interactively under VM/SP. 6 refs.

  2. A Large Ordinary Chondrite Shower in the Dominion Range

    NASA Technical Reports Server (NTRS)

    Satterwhite, C. E.; Righter, K.; Harrington, R.; McBride, K. M.; Funk, R.

    2017-01-01

    The US Antarctic Meteorite Program has visited the Dominion Range in the Transantarctic Mountains during several different seasons, including the 1985, 2003, 2008, 2010, and 2014 seasons. Total recovered meteorites from this region is over 2000. The 2008 and 2010 seasons have been fully classified and, respectively) revealing the presence of a large meteorite shower that comprises approximately 60% of all samples recovered in those two seasons. The oil immersion classification suggests that this shower is LL chondrite material, whereas published magnetic susceptibility (MS; log chi) measurements yield L chondrite values. However, usually random sampling of a large collection like this would uncover EOC material for which we have prepared thin sections. In this case, no LL chondrite materials have been found in thin section, suggesting that the shower might instead be an L chondrite. L and LL chondrites are notoriously difficult to distinguish using oil immersion techniques. To better characterize this large group of samples, we have decided to examine some of the large members of this group, using EMPA analysis of the olivines to verify the classifications. With a compositional link between this subset of samples, and the MS measurements, we can more confidently classify the samples making up this pairing group. Subsequently, more accurate and meaningful comparisons may be drawn between this pairing group and some other Antarctic pairing groups such as from the Queen Alexandra Range (QUE), and Lewis Cliffs Ice Tongue (LEW). electron microprobe analysis

  3. Tagging spallation backgrounds with showers in water Cherenkov detectors

    NASA Astrophysics Data System (ADS)

    Li, Shirley Weishi; Beacom, John F.

    2015-11-01

    Cosmic-ray muons and especially their secondaries break apart nuclei ("spallation") and produce fast neutrons and beta-decay isotopes, which are backgrounds for low-energy experiments. In Super-Kamiokande, these beta decays are the dominant background in 6-18 MeV, relevant for solar neutrinos and the diffuse supernova neutrino background. In a previous paper, we showed that these spallation isotopes are produced primarily in showers, instead of in isolation. This explains an empirical spatial correlation between a peak in the muon Cherenkov light profile and the spallation decay, which Super-Kamiokande used to develop a new spallation cut. However, the muon light profiles that Super-Kamiokande measured are grossly inconsistent with shower physics. We show how to resolve this discrepancy and how to reconstruct accurate profiles of muons and their showers from their Cherenkov light. We propose a new spallation cut based on these improved profiles and quantify its effects. Our results can significantly benefit low-energy studies in Super-Kamiokande, and will be especially important for detectors at shallower depths, like the proposed Hyper-Kamiokande.

  4. Ozone-initiated VOC and particle emissions from a cleaning agent and an air freshener: risk assessment of acute airway effects.

    PubMed

    Nørgaard, A W; Kudal, J D; Kofoed-Sørensen, V; Koponen, I K; Wolkoff, P

    2014-07-01

    Emissions of volatile organic compounds and ultrafine particles from a kitchen cleaning agent (cream) and plug-in air freshener were investigated in a 20 m(3) walk-in climate chamber at low (~5 ppb) and high ozone (~50 ppb) test concentrations and 0.6 air exchange rate. The products emitted terpenes, inter alia limonene, dihydromyrcenol, geraniol, linalool, and glycol ethers. The ozone-initiated reaction products of these compounds were measured by air sampling on Tenax TA followed by thermal desorption GC-MS and air sampling on DNPH cartridges followed by liquid extraction and HPLC-UV analysis. Particle formation was monitored simultaneously. A number of oxygenated and poly-oxygenated reaction products were identified and risk assessed for acute airway effects: formaldehyde, acetaldehyde, acetone, 4-acetyl-1-methylcyclohexene, 6-methyl-5-heptene-2-one, 3-isopropenyl-6-oxo-heptanal, and 4-oxo-pentanal. These compounds generally increased initially at the high ozone concentration, while the terpenes decayed, concurrent with their consumption of ozone. At high ozone concentration, the plug-in air freshener resulted in concentrations of formaldehyde and 4-oxopentanal that may give rise to concern about sensory irritation and airflow limitation, respectively. At high ozone concentration, the kitchen cleaning agent and air freshener resulted in peak particle mass concentrations at 81 μg/m(3) (8.5×10(5) #/cm(3)) and 24 μg/m(3) (2.3×10(4) #/cm(3)), respectively. At low ozone concentration, the particle concentration peaked at 4 μg/m(3) (1.0×10(5) #/cm(3)) after the application of the kitchen cleaning agent, while no increase was observed for the air freshener. The particles, in view of their organic composition and concentration, are not considered to cause acute airway effects. Testing under realistic conditions that mimic user pattern behavior is warranted to obtain acute and longer-term exposure data at realistic indoor ozone concentrations.

  5. How to select the best tree planting locations to enhance air pollution removal in the MillionTreesNYC initiative.

    PubMed

    Morani, Arianna; Nowak, David J; Hirabayashi, Satoshi; Calfapietra, Carlo

    2011-05-01

    Highest priority zones for tree planting within New York City were selected by using a planting priority index developed combining three main indicators: pollution concentration, population density and low canopy cover. This new tree population was projected through time to estimate potential air quality and carbon benefits. Those trees will likely remove more than 10,000 tons of air pollutants and a maximum of 1500 tons of carbon over the next 100 years given a 4% annual mortality rate. Cumulative carbon storage will be reduced through time as carbon loss through tree mortality outweighs carbon accumulation through tree growth. Model projections are strongly affected by mortality rate whose uncertainties limit estimations accuracy. Increasing mortality rate from 4 to 8% per year produce a significant decrease in the total pollution removal over a 100 year period from 11 000 tons to 3000 tons.

  6. Initial proof-of-principle for near room temperature Xe and Kr separation from air with MOFs

    SciTech Connect

    Thallapally, Praveen K.; Strachan, Denis M.

    2012-06-06

    Materials were developed and tested in support of the U.S. Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Separations and Waste Forms Campaign. Specifically, materials are being developed for the removal of Xenon and krypton from gaseous products of nuclear fuel reprocessing unit operations. During FY 2012, Three Metal organic framework (MOF) structures were investigated in greater detail for the removal and storage of Xe and Kr from air at room temperature. Our breakthrough measurements on Nickel based MOF could capture and separate parts per million levels of Xe from Air (40 ppm Kr, 78% N2, 21% O2, 0.9% Ar, 0.03% CO2). Similarly, the selectivity can be changed from Xe > Kr to Xe < Kr simply by changing the temperature in another MOF. Also for the first time we estimated the cost of the metal organic frameworks in bulk.

  7. National-Scale Air Quality Data Assessment: Initial Findings from the Near-Road NO2 Monitoring Program

    NASA Astrophysics Data System (ADS)

    DeWinter, J. L.

    2015-12-01

    In 2010, the U.S. Environmental Protection Agency (EPA) revised the National Ambient Air Quality Standards (NAAQS) for nitrogen dioxide (NO2) to include a primary health-based standard for hourly NO2. NO2 is a reactive gas that is emitted from motor vehicles, such as cars, trucks, and off-road equipment, as well as non-mobile sources, and is known to adversely affect human respiratory health. In conjunction with the NAAQS revision, EPA has mandated air quality monitoring next to selected major roadways throughout the United States that are in large urban areas where peak hourly NO2 concentrations are expected. Monitoring began in phases during 2012-2015 and included nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter smaller than 2.5 microns (PM2.5) at 40 monitoring sites nationwide. We conducted a national-scale review of near-road air pollutant concentrations, identified areas where high concentrations of NO2, PM2.5, and CO occurred, and evaluated how concentrations varied by factors such as location, distance to roadway, fleet mix characteristics, and traffic volume. We present the findings from our national near-road data assessment for the 2014 monitoring year.

  8. Quark-gluon tagging with shower deconstruction: Unearthing dark matter and Higgs couplings

    NASA Astrophysics Data System (ADS)

    Ferreira de Lima, Danilo; Petrov, Petar; Soper, Davison; Spannowsky, Michael

    2017-02-01

    The separation of quark and gluon initiated jets can be an important way to improve the sensitivity in searches for new physics or in measurements of Higgs boson properties. We present a simplified version of the shower deconstruction approach as a novel observable for quark-gluon tagging. Assuming topoclusterlike objects as input, we compare our observable with energy correlation functions and find a favorable performance for a large variety of jet definitions. We address the issue of infrared sensitivity of quark-gluon discrimination. When this approach is applied to dark matter searches in monojet final states, limitations from small signal-to-background ratios can be overcome. We also show that quark-gluon tagging is an alternative way of separating weak boson from gluon-fusion production in the process p +p →H +jet+jet+X .

  9. Direct tests of micro channel plates as the active element of a new shower maximum detector

    DOE PAGES

    Ronzhin, A.; Los, S.; Ramberg, E.; ...

    2015-05-22

    We continue the study of micro channel plates (MCP) as the active element of a shower maximum (SM) detector. We present below test beam results obtained with MCPs detecting directly secondary particles of an electromagnetic shower. The MCP efficiency to shower particles is close to 100%. Furthermore, the time resolution obtained for this new type of the SM detector is at the level of 40 ps.

  10. Optical observations of the spatial and temporal relations between sprites and meteors during the 2009 Geminid shower

    NASA Astrophysics Data System (ADS)

    Yair, Y.; Ben-Yona, M.; Reicher, N.; Mezuman, K.; Price, C. G.

    2010-12-01

    Meteors had long been suggested as a possible factor affecting the generation and location of sprite elements, via deposition of dust particles and ablation prodcuts that serve as ignition points by locally enhancing the transient quasi-electrostatic electric field in mesospheric altitudes (Zabotin and Wright, 2001). Since during a meteor shower the flux of incoming particles is much larger than during non-shower nights, it is reasonable to assume that the presence of relatively large amounts of particles at mesospheric altitudes facilitates the generation of sprites above active thunderstorms, when the TLEs occur directly below the deposition region of the shower. We report observations of the co-occurrence in space and time of bright meteors and sprites during the night of December 10-11 2009, three days before the reported peak of the Geminid meteor shower (IMO) which had a maximum ZHR ~120 per hour. A typical winter storm system was located over the Mediterranean Sea, some 300 km north-west of Tel-Aviv, where our cameras were located. A total of 37 sprites (columns and carrots) were imaged during a 5 hour period, intermittently with 12 meteor trails detected within the same field of view. By calculating the meteor trajectories and the locations and the dimensions of the sprite elements, we show a close temporal and spatial proximity between them. From the angular distance between the shower radiant and the observed bright segment of the meteors' orbits, the beginning altitudes were found to be 87-102±5 km (in agreement with Koten et al.,2004), and termination heights 82-96±5 km. Sprite lengths and altitudes were also computed (initiation at ~75±5km), and found to overlap with the heights where meteors visually terminated. In some cases the sprites were observed just minutes after the meteors occurred, with only a couple of km separation from their location. However no direct and immediate one-to-one causality was detected. Possible mechanisms for meteor

  11. Recent shower outbursts detected by the Canadian Meteor Orbit Radar (CMOR)

    NASA Astrophysics Data System (ADS)

    Brown, P.

    2016-01-01

    We present recent detections of short-duration shower outbursts as measured by the Canadian Meteor Orbit Radar (CMOR) between 2013-2016. In this interval, CMOR detected two strong shower outbursts unlinked to known showers. These included an outburst of the Kappa Cancrids (KCA - IAU 793) on January 5, 2015 and from the Gamma Lyrids (GLY - IAU 794) on February 7, 2015. Both have an orbit consistent with a Halley-type comet (HTC) or nearly isotropic-comet. Analysis of GLY activity also revealed a previously unreported annual shower, the September Ursae Majorids, (SUR - IAU 795).

  12. Dynamical modeling validation of parent bodies associated with newly discovered CMN meteor showers

    NASA Astrophysics Data System (ADS)

    Šegon, Damir; Vaubaillon, Jérémie; Gural, Peter S.; Vida, Denis; Andreić, Željko; Korlević, Korado; Skokić, Ivica

    2017-01-01

    Context. Results from previous searches for new meteor showers in the combined Croatian Meteor Network and SonotaCo meteor databases suggested possible parent bodies for several newly identified showers. Aims: We aim to perform an analysis to validate the connection between the identified showers and candidate parent bodies. Methods: Simulated particles were ejected from candidate parent bodies, a dynamical modeling was performed and the results were compared to the real meteor shower observations. Results: From the 13 analysed cases, three were found to be connected with comets, four with asteroids which are possibly dormant comets, four were inconclusive or negative, and two need more observational data before any conclusions can be drawn.

  13. Addendum to ``Coherent radio pulses from GEANT generated electromagnetic showers in ice''

    NASA Astrophysics Data System (ADS)

    Razzaque, Soebur; Seunarine, Surujhdeo; Chambers, Scott W.; Besson, David Z.; McKay, Douglas W.; Ralston, John; Seckel, David

    2004-02-01

    We reevaluate our published calculations of electromagnetic showers generated by GEANT 3.21 and the radio frequency pulses they produce in ice. We are prompted by a recent report showing that GEANT 3.21 modeled showers are sensitive to internal settings in the electron tracking subroutine. We report the shower and pulse characteristics obtained with different settings of GEANT 3.21 and with GEANT 4. The default setting of electron tracking in GEANT 3.21 we used in previous work speeds up the shower simulation at the cost of information near the end of the tracks. We find that settings tracking e- and e+ to lower energy yield a more accurate calculation, a more intense shower, and proportionately stronger radio pulses at low frequencies. The key features of the showers and pulses agree among GEANT 4 and Zas, Halzen, and Stanev and properly set GEANT 3.21 codes. At high frequencies the relation between the shower tracking algorithm and the pulse spectrum is more complex. We obtain radial distributions of shower particles and phase distributions of pulses from 100 GeV showers that are consistent with our published results.

  14. Indoor transient SOA formation from ozone + α-pinene reactions: Impacts of air exchange and initial product concentrations, and comparison to limonene ozonolysis

    NASA Astrophysics Data System (ADS)

    Youssefi, Somayeh; Waring, Michael S.

    2015-07-01

    The ozonolysis of reactive organic gases (ROG), e.g. terpenes, generates secondary organic aerosol (SOA) indoors. The SOA formation strength of such reactions is parameterized by the aerosol mass fraction (AMF), a.k.a. SOA yield, which is the mass ratio of generated SOA to oxidized ROG. AMFs vary in magnitude both among and for individual ROGs. Here, we quantified dynamic SOA formation from the ozonolysis of α-pinene with 'transient AMFs,' which describe SOA formation due to pulse emission of a ROG in an indoor space with air exchange, as is common when consumer products are intermittently used in ventilated buildings. We performed 19 experiments at low, moderate, and high (0.30, 0.52, and 0.94 h-1, respectively) air exchange rates (AER) at varying concentrations of initial reactants. Transient AMFs as a function of peak SOA concentrations ranged from 0.071 to 0.25, and they tended to increase as the AER and product of the initial reactant concentrations increased. Compared to our similar research on limonene ozonolysis (Youssefi and Waring, 2014), for which formation strength was driven by secondary ozone reactions, the AER impact for α-pinene was opposite in direction and weaker, while the initial reactant product impact was in the same direction but stronger for α-pinene than for limonene. Linear fits of AMFs for α-pinene ozonolysis as a function of the AER and initial reactant concentrations are provided so that future indoor models can predict SOA formation strength.

  15. Aerosol Direct Radiative Forcing in the Southern Appalachian Mountains: Initial Results from the Appalachian Atmospheric Interdisciplinary Research (AppalAIR) Facility

    NASA Astrophysics Data System (ADS)

    Taubman, B.; Sherman, J.; Sheridan, P. J.; Perry, L. B.; Neufeld, H.; Emanuel, R. E.; Tashakkori, R.; Bowman, D.; Long, C.

    2009-12-01

    AppalAIR (Appalachian Atmospheric Interdisciplinary Research, http://appalair.appstate.edu/) is a new interdisciplinary, atmospheric research facility located on the campus of Appalachian State University (1076 m; 36.2° N, 81.7° W) in the southern Appalachian Mountains. The facility was designed to investigate air pollution formation and transport, the relationships among biogenic and anthropogenic inputs to a changing climate, and the effects of these factors on regional ecosystems. AppalAIR is a collaborating member of the NOAA Earth System Research Laboratory Global Monitoring Division (NOAA/ESRL GMD) Collaborative Global Aerosol Network (http://www.esrl.noaa.gov/gmd/aero/net/app/index.html). Measurements are made from a 34 m tower and include aerosol light scattering (3-λ nephelometer) and absorption (3-λ PSAP, 7-λ aethalometer, 6-λ UV aethalometer), particle number concentration (CPC), and aerosol chemistry, size, and morphology using SPME/GC-MS and SEM analyses on 24 h filter samples. Initial results indicate alternating periods of small, highly absorptive (ssa < 0.90) fractal agglomerates and large, highly scattering (ssa > 0.95) spherical particles that are strongly dependent upon the highly variably meteorological patterns that have occurred over the summertime (JJA) in the southeastern U.S. By quantifying the aerosol direct radiative forcing during discrete meteorological patterns as defined by statistical cluster analysis as well as from specific aerosol chemical sources, we are able to extrapolate the results beyond the immediate region.

  16. Thermal destruction of dried vegetative yeast cells and dried bacterial spores in a convective hot air flow: strong influence of initial water activity.

    PubMed

    Fine, Frédéric; Gervais, Patrick

    2005-01-01

    Thermal treatment of Bacillus subtilis spores and Saccharomyces cerevisiae cells dried on glass beads was performed at various initial water activities (in the range 0.10-0.90). Experiments were carried out at 150 degrees C, 200 degrees C and 250 degrees C for 5-120 s. Significant destruction of up to 10(7) vegetative cells and up to 10(5) spores g(-1) was achieved, depending upon treatment conditions. This study demonstrated that the initial water activity (a(w)) value of a sample is very important in the destruction or survival of microorganisms treated with hot air stresses. As described previously, the heat resistance of spores and vegetative cells was strongly enhanced by low initial a(w) values until an optimal a(w) value between 0.30 and 0.50, with maximal viability at 0.35 for both S. cerevisiae and B. subtilis. However, our results highlighted for the first time that very low initial a(w) values (close to 0.10) greatly improved the destruction of spores and vegetative cells. Factors and possible mechanisms involved in the death of vegetative cells and spores are discussed.

  17. Inhibited flammability and surface inactivation of wood irradiated by low energy hydrogen ion showers (LEHIS)

    NASA Astrophysics Data System (ADS)

    Blantocas, Gene Q.; Mateum, Philip Edward R.; Orille, Ross William M.; Ramos, Rafael Julius U.; Monasterial, Jonathan Lee C.; Ramos, Henry J.; Bo-ot, Luis Ma. T.

    2007-06-01

    Changes on the properties of wood irradiated by low energy hydrogen ion showers (LEHIS) were examined. The experimental facility employed was an in-house constructed, compact gas discharge ion source with beam energies maintained approximately in the 1 keV range fixed at 1 mA discharge current, 3 mTorr gas filling pressure. Wood specimens used were of species endemic in the Philippines namely Shorea sp., Shorea polysperma and Cocos nucifera. Results showed the processed samples manifested characteristics of inhibited flammability, and became relatively hydrophobic after the treatment. In the fire resistance test, it was also observed during initial flaming that the processed surfaces accumulated less soot attesting to a much lower smoldering rate, i.e. lesser combustibility. To assess the increase in fire endurance time for the processed wood against the control substrates, a non-directional, two-tailed t-test was utilized. Significant at the 0.05 level, the t-statistic measured 9.164 as opposed to only 4.303 in its corresponding critical value at two degrees of freedom. Hence, the treatment appeared to show strong statistical evidence of being effective in enhancing fire resistance. The processed specimens also exhibited moisture absorptive inhibition time of more than 10 min versus an average absorption period of just 8 s for the unprocessed samples. Spectroscopy using a cast steel mass analyzer indicated a predominance of H+ with faint signals of H2+in the ion showers. It is hypothesized that the monatomic ion plays an essential participatory role in the surface modification process. Data from an earlier work using Narra wood (Pterocarpus indicus) [G.Q. Blantocas, H.J. Ramos, M. Wada, Jpn. J. Appl. Phys. 45 (2006) 8498] was extended in the current study to substantiate this hypothesis. The data is now presented as current density ratio H+ /H2+versus the change rate constant K of the wetting model equation. It is shown that wood affinity to water decreased as the

  18. The established meteor showers as observed by CAMS

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.; Nénon, Q.; Albers, J.; Gural, P. S.; Haberman, B.; Holman, D.; Morales, R.; Grigsby, B. J.; Samuels, D.; Johannink, C.

    2016-03-01

    Orbital elements are presented for 70 of the 95 meteor showers considered ;established; by the International Astronomical Union. From 2010 October 21 until 2013 March 31, the low-light-video based Cameras for Allsky Meteor Surveillance project (CAMS) measured a total of 110,367 meteoroid trajectories and pre-atmospheric orbits from mostly -2 to +4 magnitude meteors with a precision of <2° (median 0.4°) in apparent radiant direction and <10% (median 0.9%) in speed. This paper discusses how the already established showers manifest in this data. Newly resolved components in the radiant distribution shed light on the dynamics and physical lifetime of parent bodies and their meteoroids. Many multi-component showers have associated parent bodies with nodal lines not much rotated from that of their meteoroids (Encke Complex, Machholz Complex, Phaethon Complex, and now also the 169P/NEAT Complex). These may result from a parent body disruption cascade, with the disruption-generated meteoroids fading on the short timescale of a few hundred to a few thousand years. In particular, the Northern and Southern Taurids of the Encke Complex are decomposed here into 19 individual streams. Seven of these streams can be paired with mostly sub-km sized potential parent body asteroids that move in 2P/Encke-like orbits that span the narrow semi-major axis range of 2.20-2.35 AU. The meteoroids in these Taurid streams do not survive long enough for the nodal line to fully rotate relative to that of their parent body.

  19. Periodic Comet Showers, Mass Extinctions, and the Galaxy

    NASA Technical Reports Server (NTRS)

    Rampino, M. R.; Stothers, R. B.

    2000-01-01

    Geologic data on mass extinctions of life and evidence of large impacts on the Earth are thus far consistent with a quasi-periodic modulation of the flux of Oort cloud comets. Impacts of large comets and asteroids are capable of causing mass extinction of species, and the records of large impact craters and mass show a correlation. Impacts and extinctions display periods in the range of approximately 31 +/- 5 m.y., depending on dating methods, published time scales, length of record, and number of events analyzed. Statistical studies show that observed differences in the formal periodicity of extinctions and craters are to be expected, taking into consideration problems in dating and the likelihood that both records would be mixtures of periodic and random events. These results could be explained by quasi-periodic showers of Oort Cloud comets with a similar cycle. The best candidate for a pacemaker for comet showers is the Sun's vertical oscillation through the plane of the Galaxy, with a half-period over the last 250 million years in the same range. We originally suggested that the probability of encounters with molecular clouds that could perturb the Oort comet cloud and cause comet showers is modulated by the Sun's vertical motion through the galactic disk. Tidal forces produced by the overall gravitational field of the Galaxy can also cause perturbations of cometary orbits. Since these forces vary with the changing position of the solar system in the Galaxy, they provide a mechanism for the periodic variation in the flux of Oort cloud comets into the inner solar system. The cycle time and degree of modulation depend critically on the mass distribution in the galactic disk. Additional information is contained in the original extended abstract.

  20. Advanced Air Traffic Management Research (Human Factors and Automation): NASA Research Initiatives in Human-Centered Automation Design in Airspace Management

    NASA Technical Reports Server (NTRS)

    Corker, Kevin M.; Condon, Gregory W. (Technical Monitor)

    1996-01-01

    NASA has initiated a significant thrust of research and development focused on providing the flight crew and air traffic managers automation aids to increase capacity in en route and terminal area operations through the use of flexible, more fuel-efficient routing, while improving the level of safety in commercial carrier operations. In that system development, definition of cognitive requirements for integrated multi-operator dynamic aiding systems is fundamental. The core processes of control and the distribution of decision making in that control are undergoing extensive analysis. From our perspective, the human operators and the procedures by which they interact are the fundamental determinants of the safe, efficient, and flexible operation of the system. In that perspective, we have begun to explore what our experience has taught will be the most challenging aspects of designing and integrating human-centered automation in the advanced system. We have performed a full mission simulation looking at the role shift to self-separation on board the aircraft with the rules of the air guiding behavior and the provision of a cockpit display of traffic information and an on-board traffic alert system that seamlessly integrates into the TCAS operations. We have performed and initial investigation of the operational impact of "Dynamic Density" metrics on controller relinquishing and reestablishing full separation authority. (We follow the assumption that responsibility at all times resides with the controller.) This presentation will describe those efforts as well as describe the process by which we will guide the development of error tolerant systems that are sensitive to shifts in operator work load levels and dynamic shifts in the operating point of air traffic management.