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Sample records for air shower development

  1. The development of air shower in the iron absorber

    NASA Technical Reports Server (NTRS)

    Hazama, M.; Dake, S.; Harada, K.; Kawamoto, M.; Sakata, M.; Yamamoto, Y.; Sugihara, T.

    1985-01-01

    The iron open-sandwich experiments to observe one dimensional development of individual air showers were carried out at Akeno Observatory. One dimensional energy flow, incident energy and production height of shower is estimated using the data of size and age obtained from the above experiment and simple calculation.

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

    NASA Technical Reports Server (NTRS)

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

  3. 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.

  4. Comparison of big event with calculations of the air shower development

    NASA Technical Reports Server (NTRS)

    Niwa, M.; Misaki, A.; Matano, T.

    1985-01-01

    The incidence of high energy hadrons and electron-photons in air showers at various stages of development is calculated. Numerical calculation is used to solve the diffusion equation for a nuclear cascade and analytical calculation for cascade shower induced gamma rays. From these calculations, one can get the longitudinal development of the high energy hadron and electron-photon components, and the energy spectra of these components at various depths of air shower development. The total number of hadrons (N sub H) and electron-photon components (N sub gamma) are related according to stages of the air shower development and primary energy. The relation of the total energy of hadron and electron-photon component above the threshold energy is given. The energy balance between both components is also a useful parameter to study high energy events accompanying air showers. The relation of N sub H and fractional hadronic energy E (sum E sub H sup gamma/sum E sub H sup gamma + Sum E sub gamma) is calculated. This relation is helpful to understand the stage of air shower development(t) and primary energy (E sub p).

  5. 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. PMID:18999734

  6. Extensive Air Shower Characteristics as Functions of Shower Age

    NASA Astrophysics Data System (ADS)

    Giller, Maria; Stojek, Hubert; Wieczorek, Grzegorz

    We show that extensive air showers (EAS) are all very similar when described by shower age and Molière length unit. This allows to analyze fluorescence and Cherenkov light emitted by showers in a unified and simple way.

  7. 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…

  8. Air-shower spectroscopy at horizons

    NASA Astrophysics Data System (ADS)

    Fargion, D.

    2006-07-01

    Downward cosmic rays are mostly revealed on the ground by their air-showers diluted and filtered secondary μμ traces and/or by their (Cerenkov - Fluorescent) light because of the high altitude numerous and luminous electromagnetic ee,γ shower component. Horizontal and upward air-showers are even more suppressed by deeper atmosphere opacity and by the Earth shadows. In such noise-free horizontal and upward directions rare Ultra High Cosmic rays and rarer neutrino induced air-showers may shine, mostly mediated by resonant PeV ν¯+e→W interactions in air or by higher energy tau air-showers originated by ν skimming the Earth. At high altitude (mountains, planes, balloons) the air density is so rarefied that nearly all common air-showers might be observed at their maximal growth at a tuned altitude and direction. The arrival angle samples different distances and the corresponding most probable primary cosmic ray energy. The larger and larger distances (between observer and C.R. interaction) make wider and wider the shower area and it enlarges the probability of being observed (up to three orders of magnitude more than vertical showers); the observation of a maximal electromagnetic shower development may amplify the signal by two three orders of magnitude (with respect to a suppressed shower at sea level); the peculiar altitude angle range (ten twenty km height and ≃80 90 zenith angle) may disentangle at best the primary cosmic ray energy and composition. Even from existing mountain observatories the up-going air-showers may trace, above the horizons, PeV EeV high energy cosmic rays and, below the horizons, PeV EeV neutrino astronomy: their early signals may be captured in already existing gamma telescopes such as Magic at Canarie, while facing the Earth edges during (useless) cloudy nights.

  9. 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)

  10. Montecarlo simulation of photon induced air showers.

    NASA Astrophysics Data System (ADS)

    D'Ettorre Piazzoli, B.; di Sciascio, G.

    The EPAS code (Electron Photon induced Air Showers) is a three dimensional Montecarlo simulation developed to study the properties of extensive air showers generated by the interaction of high energy photons (or electrons) in the atmosphere. Results of the present simulation concern the longitudinal, lateral, temporal and angular distributions of electrons in atmospheric cascades initiated by photons of energies up to 100 TeV.

  11. Reinterpreting the development of extensive air showers initiated by nuclei and photons

    SciTech Connect

    Domenico, Manlio De; Settimo, Mariangela; Riggi, Simone; Bertin, Eric E-mail: mariangela.settimo@gmail.com E-mail: eric.bertin@ens-lyon.fr

    2013-07-01

    Ultra-high energy cosmic rays (UHECRs) interacting with the atmosphere generate extensive air showers (EAS) of secondary particles. The depth corresponding to the maximum development of the shower, X{sub max}, is a well-known observable for determining the nature of the primary cosmic ray which initiated the cascade process. In this paper, we present an empirical model to describe the distribution of X{sub max} for EAS initiated by nuclei, in the energy range from 10{sup 17} eV up to 10{sup 21} eV, and by photons, in the energy range from 10{sup 17} eV up to 10{sup 19.6} eV. Our model adopts the generalized Gumbel distribution motivated by the relationship between the generalized Gumbel statistics and the distribution of the sum of non-identically distributed variables in dissipative stochastic systems. We provide an analytical expression for describing the X{sub max} distribution for photons and for nuclei, and for their first two statistical moments, namely (X{sub max}) and σ{sup 2}(X{sub max}). The impact of the hadronic interaction model is investigated in detail, even in the case of the most up-to-date models accounting for LHC observations. We also briefly discuss the differences with a more classical approach and an application to the experimental data based on information theory.

  12. 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.

  13. On special features of the longitudinal development of extensive air showers and on the spectrum of cosmic rays

    SciTech Connect

    Stenkin, Yu. V.

    2008-01-15

    It is shown that, in the development of an extensive air shower (EAS) initiated by primary cosmic rays in the Earth's atmosphere, there is a special feature that sterms from the violation of equilibrium between EAS components and whose inclusion requires revising both EAS phenomenology and the existing experimental data obtained by indirectly measuring the energy spectrum of cosmic rays by the EAS method.

  14. Hadronic multiparticle production at ultrahigh energies and extensive air showers

    SciTech Connect

    Ulrich, Ralf; Engel, Ralph; Unger, Michael

    2011-03-01

    Studies of the nature of cosmic ray particles at the highest energies are based on the measurement of extensive air showers. Most cosmic ray properties can therefore be obtained only from the interpretation of air shower data and are thus dependent on predictions of hadronic interaction models at ultrahigh energies. We discuss different scenarios of model extrapolations from accelerator data to air shower energies and investigate their impact on the corresponding air shower predictions. To explore the effect of different extrapolations by hadronic interaction models we developed an ad hoc model. This model is based on the modification of the output of standard hadronic interaction event generators within the air shower simulation process and allows us to study the impact of changing interaction features on the air shower development. In a systematic study we demonstrate the resulting changes of important air shower observables and also discuss them in terms of the predictions of the Heitler model of air shower cascades. It is found that the results of our ad hoc modifications are, to a large extent, independent of the choice of the underlying hadronic interaction model.

  15. Neutrons in extensive air showers

    SciTech Connect

    Stenkin, Yu. V.; Djappuev, D. D.; Valdes-Galicia, J. F.

    2007-06-15

    The main properties of the so-called neutron bursts produced by the passage of extensive air showers (EASs) through a detector array and the properties of these EASs are considered using the experiments that are being or have been carried out previously with the Carpet-2 array at Baksan Neutrino Observatory of the Institute for Nuclear Research, Russian Academy of Sciences, and at Cosmic-Ray Station of UNAM in Mexico as examples. We show that no exotic processes are required to explain the nature of neutron bursts. Based on a working prototype of the previously proposed MULTICOM array, we also show that this phenomenon can be successfully used in studying the EAS hadronic component and that adding special thermal neutron detectors can improve significantly the capabilities of the array for EAS study.

  16. 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.

  17. 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.

  18. Lateral distribution of electrons of air showers

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    The lateral distribution of electrons (LDE) of the air showers of size 10 to the 5th power to 10 to the 6th power was studied within one MU. It was found that the LDE of the air showers observed is well represented by NKG function except for vicinity of the core. It was also found that LDE measured by thin scintillators does not differ from that measured by thick ones of 50mm thickness.

  19. 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.

  20. Monte Carlo simulation of photon-induced air showers

    NASA Astrophysics Data System (ADS)

    D'Ettorre Piazzoli, B.; di Sciascio, G.

    1994-05-01

    The EPAS code (Electron Photon-induced Air Showers) is a three-dimensional Monte Carlo simulation developed to study the properties of extensive air showers (EAS) generated by the interaction of high energy photons (or electrons) in the atmosphere. Results of the present simulation concern the longitudinal, lateral, temporal and angular distributions of electrons in atmospheric cascades initiated by photons of energies up to 10^3 TeV.

  1. 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.

  2. The angular resolution of air shower gamma ray telescopes

    NASA Technical Reports Server (NTRS)

    Morello, C.; Navarra, G.; Periale, L.; Vallania, P.

    1985-01-01

    A crucial charactristic of air shower arrays in the field of high energy gamma-ray astronomy is their angular resolving power, the arrival directions being obtained by the time of flight measurements. A small air shower array-telescope is used to study the resolution in the definition of the shower front as a function of the shower size.

  3. Muons in Air Showers at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Unger, M.

    We present measurements of muons in air showers at ultra-high energies with the Pierre Auger Observatory. The number of muons at the ground in air showers detected at large zenith angles is determined as a function of energy and the results are compared to air shower simulations. Furthermore, using data collected at zenith angles smaller than 60°, rescaling factors are derived that quantify the deficit of muon production in air shower simulations.

  4. 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.

  5. Quark matter induced extensive air showers

    SciTech Connect

    Lawson, Kyle

    2011-05-15

    If the dark matter of our Galaxy is composed of nuggets of quarks or antiquarks in a color superconducting phase there will be a small but nonzero flux of these objects through the Earth's atmosphere. A nugget of quark matter will deposit only a small fraction of its kinetic energy in the atmosphere and is likely to be undetectable. If however the impacting object is composed of antiquarks, the energy deposited can be quite large. In this case nuclear annihilations within the nugget will trigger an extensive air shower the particle content of which is similar to that produced by an ultrahigh energy cosmic ray. This paper gives a qualitative description of the basic properties of such a shower. Several distinctions from an air shower initiated by a single ultrahigh energy nucleus will be described, allowing these events to be distinguished from the cosmic ray background. The subtlety of these features may mean that some fraction of the high energy cosmic ray spectrum may in fact be due to this type of dark matter interaction. The estimated flux of dark matter nuggets and the energy deposited in the atmosphere are such that the Pierre Auger Observatory may prove an ideal facility to place constraints on the flux of heavy quark matter objects. This paper attempts to highlight the best techniques to search for a quark matter signature through an extensive air shower signal.

  6. 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.

  7. Structure of air shower disc near the core

    NASA Technical Reports Server (NTRS)

    Inoue, N.; Kawamoto, M.; Misaki, Y.; Maeda, T.; Takeuchi, T.; Toyoda, Y.

    1985-01-01

    The longitudinal structure of the air shower disk is studied by measuring the arrival time distributions of air shower particles for showers with electron size in the range 3.2 x 10 to the 5.5. power to 3.2 x 10 to the 7.5 power in the Akeno air-shower array (930 gcm squared atmospheric depth). The average FWHM as a parameter of thickness of air shower disk increases with core distances at less than 50m. AT the present stage, dependence on electron size, zenith angle and air shower age is not apparent. The average thickness of the air shower disk within a core distance of 50m could be determined by an electromagnetic cascade starting from the lower altitude.

  8. Acoustic detection of air shower cores

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  9. 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.

  10. A critical analysis of air shower structure functions and size spectrum measurements with the NBU air shower array

    NASA Technical Reports Server (NTRS)

    Chaudhuri, N.; Basak, D. K.

    1985-01-01

    A total of 11,000 showers in the size range 10 to the 4 to 10 to the 6 particles so far detected by the NBU air shower array has been analyzed using five different structure functions. A comparison of structure functions in terms: (1) of shower size; and (2) electron density at various core distances has been discussed to indicate the present status of structure functions in air shower analysis.

  11. Thickness of the particle swarm in cosmic ray air showers

    NASA Technical Reports Server (NTRS)

    Linsley, J.

    1985-01-01

    The average dispersion in arrival time of air shower particles detected with a scintillator at an impact parameter r is described with accuracy 5-10% by the empirical formula sigma = Sigma sub to (1+r/r sub t) sup b, where Sigma sub to = 2.6 ns, r sub t = 30m and b = (1.94 + or - .08) (0.39 + or - .06) sec Theta, for r 2 km, 10 to the 8th power E 10 to the 11th power GeV, and Theta 60 deg. (E is the primary energy and theta is the zenith angle). The amount of fluctuation in sigma sub t due to fluctuations in the level of origin and shower development is less than 20%. These results provide a basis for estimating the impact parameters of very larger showers with data from very small detector arrays (mini-arrays). The energy of such showers can then be estimated from the local particle density. The formula also provides a basis for estimating the angular resolution of air shower array-telescopes.

  12. A mini-array for large air showers

    NASA Technical Reports Server (NTRS)

    Ng, L. K.; Chan, S. K.; Hazen, W. E.; Hazen, E. S.

    1985-01-01

    A mini-array that utilizes the Linsley effect is proposed for the measurement of large air showers. An estimate of the detectable shower rates for various shower sizes is made. Details of the detection and data collection systems are also described.

  13. Relation between hadronic interactions and ultra-high energy extensive air showers

    NASA Astrophysics Data System (ADS)

    Ulrich, Ralf; Baus, Colin; Engel, Ralph

    2015-08-01

    The simulation of hadronic interactions is of fundamental importance for the analysis of extensive air showers. The details of the relation between the measurement of hadronic interactions at accelerators and the impact on the air shower development is very difficult to evaluate. Several possibilities to study this relation are presented here.

  14. Surveys of Microwave Emission from Air Showers

    NASA Astrophysics Data System (ADS)

    Kuramoto, Kazuyuki; Ogio, Shoichi; Iijima, Takashi; Yamamoto, Tokonatsu

    2011-09-01

    A possibility of detection of microwave molecular bremsstrahlung radiation from Extensive Air Showers was reported by AMBER group [1] [2]. This method has a potential to provide a high duty cycle and a new technique for measuring longitudinal profile of EAS. To survey this microwave emission from EAS, we built prototype detectors using parabolic antenna dishes for broadcasting satellites, and we are operating detectors with a small EAS array at Osaka City Univercity. Here, we report our detector configurations and the current experimental status.

  15. 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.

  16. Transition effect of air shower particles in plastic scintillators

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    The transition effect of air shower particles in the plastic scintillators near the core was measured by scintillators of various thickness. The air showers selected for the measurement were of 10,000. Results obtained are as follows: (1) the multiplication of shower particles in the scintillators is less than 20% for that of 50 mm thickness; (2) dependence of the transition effect on age parameter is not recognized within the experimental errors.

  17. pp interactions in extended air showers

    NASA Astrophysics Data System (ADS)

    Kendi Kohara, A.; Ferreira, Erasmo; Kodama, Takeshi

    2015-08-01

    Applying the recently constructed analytic representation for the pp scattering amplitudes, we present a study of p-air cross sections, with comparison to the data from Extensive Air Shower (EAS) measurements. The amplitudes describe with precision all available accelerator data at ISR, SPS and LHC energies, and its theoretical basis, together with the very smooth energy dependence of parameters controlled by unitarity and dispersion relations, permit reliable extrapolation to higher energies and to asymptotic ranges. The comparison with cosmic ray data is very satisfactory in the whole pp energy interval from 1 to 100 TeV. High energy asymptotic behaviour of cross sections is investigated in view of the geometric scaling property of the amplitudes. The amplitudes predict that the proton does not behave as a black disk even at asymptotically high enegies, and we discuss possible non-trivial consequences of this fact for pA collision cross sections at higher energies.

  18. 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.

  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. 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.

  1. Feasibility of radar detection of extensive air showers

    NASA Astrophysics Data System (ADS)

    Stasielak, J.; Engel, R.; Baur, S.; Neunteufel, P.; Šmída, R.; Werner, F.; Wilczyński, H.

    2016-01-01

    Reflection of radio waves off the short-lived plasma produced by the high-energy shower particles in the air is simulated, considering various radar setups and shower geometries. We show that the plasma produced by air showers has to be treated always as underdense. Therefore, we use the Thomson cross-section for scattering of radio waves corrected for molecular quenching and we sum coherently contributions of the reflected radio wave over the volume of the plasma disk to obtain the time evolution of the signal arriving at the receiver antenna. The received power and the spectral power density of the radar echo are analyzed. Based on the obtained results, we discuss possible modes of radar detection of extensive air showers. We conclude that the scattered signal is too weak for the radar method to provide an efficient and inexpensive method of air shower detection.

  2. The longitudinal thickness of air-shower fronts

    NASA Technical Reports Server (NTRS)

    Clay, R. W.; Elton, S. D.; Wild, N. R.; Brissenden, R. J. V.

    1985-01-01

    Linsely (1983) has proposed a technique for the detection and analysis of air showers at large distances from the shower axis based on a measurement of the shower front thickness and the assumption that this thickness is closely related to the core distance. Some of the problems involved with realizing such a technique were investigated, and some related observations are reported. The practical problems of how consistent the measurements of the shower front would be, how one would use the measurement, and how the rate of triggered events would depend on the minimum pulse width required are studied.

  3. 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...

  4. 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.

  5. 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.

  6. Microwave detection of air showers with the MIDAS experiment

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    Microwave emission from Extensive Air Showers could provide a novel technique for ultra-high energy cosmic rays detection over large area and with 100% duty cycle. We describe the design, performance and first results of the MIDAS (MIcrowave Detection of Air Showers) detector, a 4.5 m parabolic dish with 53 feeds in its focal plane, currently installed at the University of Chicago.

  7. The average longitudinal air shower profile: exploring the shape information

    NASA Astrophysics Data System (ADS)

    Conceição, R.; Andringa, S.; Diogo, F.; Pimenta, M.

    2015-08-01

    The shape of the extensive air shower (EAS) longitudinal profile contains information about the nature of the primary cosmic ray. However, with the current detection capabilities, the assessment of this quantity in an event-by-event basis is still very challenging. In this work we show that the average longitudinal profile can be used to characterise the average behaviour of high energy cosmic rays. Using the concept of universal shower profile it is possible to describe the shape of the average profile in terms of two variables, which can be already measured by the current experiments. These variables present sensitivity to both average primary mass composition and to hadronic interaction properties in shower development. We demonstrate that the shape of the average muon production depth profile can be explored in the same way as the electromagnetic profile having a higher power of discrimination for the state of the art hadronic interaction models. The combination of the shape variables of both profiles provides a new powerful test to the existing hadronic interaction models, and may also provide important hints about multi-particle production at the highest energies.

  8. Particles Production in Extensive Air Showers: GEANT4 vs CORSIKA

    NASA Astrophysics Data System (ADS)

    Sabra, M. S.; Watts, J. W.; Christl, M. J.

    2014-09-01

    Air shower simulations are essential tools for the interpretation of the Extensive Air Shower (EAS) measurements. The reliability of these codes is evaluated by comparisons with equivalent simulation calculations, and with experimental data (when available). In this work, we present GEANT4 calculations of particles production in EAS induced by primary protons and Iron in the PeV (1015 eV) energy range. The calculations, using different hadronic models, are compared with the results from the well-known air shower simulation code CORSIKA, and the results of this comparison will be discussed. Air shower simulations are essential tools for the interpretation of the Extensive Air Shower (EAS) measurements. The reliability of these codes is evaluated by comparisons with equivalent simulation calculations, and with experimental data (when available). In this work, we present GEANT4 calculations of particles production in EAS induced by primary protons and Iron in the PeV (1015 eV) energy range. The calculations, using different hadronic models, are compared with the results from the well-known air shower simulation code CORSIKA, and the results of this comparison will be discussed. This work is supported by the NASA Postdoctoral Program administered by Oak Ridge Associated Universities.

  9. Delayed muons in extensive air showers and double-front showers

    SciTech Connect

    Beisembaev, R. U.; Vavilov, Yu. N. Vildanov, N. G.; Kruglov, A. V.; Stepanov, A. V.; Takibaev, J. S.

    2009-11-15

    The results of a long-term experiment performed in the period between 1995 and 2006 with the aid of the MUON-T underground (20 mwe) scintillation facility arranged at the Tien Shan mountain research station at an altitude of 3340 m above sea level are presented. The time distribution of delayed muons with an energy in excess of 5 GeV in extensive air showers of energy not lower than 106 GeV with respect to the shower front was obtained with a high statistical significance in the delay interval between 30 and 150 ns. An effect of the geomagnetic field in detecting delayed muons in extensive air showers was discovered. This effect leads to the asymmetry of their appearance with respect to the north-south direction. The connection between delayed muons and extensive air showers featuring two fronts separated by a time interval of several tens of to two hundred nanoseconds is discussed. This connection gives sufficient grounds to assume that delayed muons originate from the decays of pions and kaons produced in the second, delayed, front of extensive air showers.

  10. 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.

  11. Angular resolution of air-shower array-telescopes

    NASA Technical Reports Server (NTRS)

    Linsley, J.

    1985-01-01

    A fundamental limit on the angular resolution of air shower array-telescopes is set by the finite number of shower particles coupled with the finite thickness of the particle swarm. Consequently the angular resolution which can be achieved in practice depends in a determinant manner on the size and number of detectors in an array-telescope, as well as on the detector separation and the timing resolution. It is also necessary to examine the meaning of particle density in whatever type of detector is used. Results are given which can be used to predict the angular resolution of a given instrument for showers of various sizes, and to compare different instruments.

  12. 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.

  13. 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.

  14. Radio signal correlation at 32 MHz with extensive air showers parameters

    NASA Astrophysics Data System (ADS)

    Knurenko, Stanislav; Petrov, Igor

    2015-08-01

    The paper presents correlations of radio signals measured at the Yakutsk array with air shower parameters: the shower energy E0 and the depth of maximum Xmax. It is shown that from radio emission measurements of air showers one can obtain individual shower parameters and hence, the mass composition of cosmic rays. In addition, we also derived a generalized formula for calculating the primary energy of the air showers.

  15. 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)

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

    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.

  16. 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.

  17. Observations of microwave continuum emission from air shower plasmas

    SciTech Connect

    Gorham, P. W.; Lehtinen, N. G.; Varner, G. S.; Hebert, C. L.; Miki, C.; Kowalski, J.; Ruckman, L.; Stokes, B. T.; Beatty, J. J.; Connolly, A.; Saltzberg, D.; Chen, P.; Hast, C.; Ng, J.; Reil, K.; Walz, D.; Conde, M. E.; Gai, W.; Konecny, R.; Power, J. G.

    2008-08-01

    We investigate a possible new technique for microwave detection of cosmic-ray extensive air showers which relies on detection of expected continuum radiation in the microwave range, caused by free-electron collisions with neutrals in the tenuous plasma left after the passage of the shower. We performed an initial experiment at the Argonne Wakefield Accelerator laboratory in 2003 and measured broadband microwave emission from air ionized via high-energy electrons and photons. A follow-up experiment at the Stanford Linear Accelerator Center in the summer of 2004 confirmed the major features of the previous Argonne Wakefield Accelerator observations with better precision. Prompted by these results we built a prototype detector using satellite television technology and have made measurements suggestive of the detection of cosmic-ray extensive air showers. The method, if confirmed by experiments now in progress, could provide a high-duty cycle complement to current nitrogen fluorescence observations.

  18. Air shower measurements with the LOPES radio antenna array

    NASA Astrophysics Data System (ADS)

    Lopes Collaboration; Haungs, A.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Auffenberg, J.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Grupen, C.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Over, S.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; LOPES Collaboration

    2009-06-01

    LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from extensive air showers. Since radio waves suffer very little attenuation, radio measurements allow the detection of very distant or highly inclined showers. These waves can be recorded day and night, and provide a bolometric measure of the leptonic shower component. LOPES is designed as a digital radio interferometer using high bandwidths and fast data processing and profits from the reconstructed air shower observables of KASCADE-Grande. The LOPES antennas are absolutely amplitude calibrated allowing to reconstruct the electric field strength which can be compared with predictions from detailed Monte-Carlo simulations. We report about the analysis of correlations present in the radio signals measured by the LOPES 30 antenna array. Additionally, LOPES operates antennas of a different type (LOPESSTAR) which are optimized for an application at the Pierre Auger Observatory. Status, recent results of the data analysis and further perspectives of LOPES and the possible large scale application of this new detection technique are discussed.

  19. The MIDAS experiment: MIcrowave Detection of Air Showers

    NASA Astrophysics Data System (ADS)

    Facal, Pedro; Bohacova, Martina; Monasor, Maria; Privitera, Paolo; Reyes, Luis C.; Williams, Cristopher

    2010-02-01

    Recent measurements suggest that extensive air showers initiated by high energy cosmic rays (above 1 EeV) emit signals in the microwave band of the EM spectrum caused by the collisions of the free-electrons with the atmospheric neutral molecules in the plasma produced by the passage of the shower. Such emission is isotropic and could allow the detection of air showers with 100% duty cycle and a calorimetric-like energy measurement - a significant improvement over current detection techniques. We have built a MIDAS prototype, which consists of a 4.5 m diameter antenna with a cluster of 55 feed-horns in the 4 GHz range, covering a 10^o x10^o field of view, with self-triggering capability. The details of the prototype and first results will be presented. )

  20. Geant4 Simulation of Air Showers using Thinning Method

    NASA Astrophysics Data System (ADS)

    Sabra, Mohammad S.; Watts, John W.; Christl, Mark J.

    2015-04-01

    Simulation of complete air showers induced by cosmic ray particles becomes prohibitive at extreme energies due to the large number of secondary particles. Computing time of such simulations roughly scales with the energy of the primary cosmic ray particle, and becomes excessively large. To mitigate the problem, only small fraction of particles can be tracked and, then, the whole shower is reconstructed based on this sample. This method is called Thinning. Using this method in Geant4, we have simulated proton and iron air showers at extreme energies (E >1016 eV). Secondary particle densities are calculated and compared with the standard simulation program in this field, CORSIKA. This work is supported by the NASA Postdoctoral Program administrated by Oak Ridge Associated Universities.

  1. Method to calibrate the absolute energy scale of air showers with ultrahigh energy photons.

    PubMed

    Homola, Piotr; Risse, Markus

    2014-04-18

    Calibrating the absolute energy scale of air showers initiated by ultrahigh energy (UHE) cosmic rays is an important experimental issue. Currently, the corresponding systematic uncertainty amounts to 14%-21% using the fluorescence technique. Here, we describe a new, independent method which can be applied if ultrahigh energy photons are observed. While such photon-initiated showers have not yet been identified, the capabilities of present and future cosmic-ray detectors may allow their discovery. The method makes use of the geomagnetic conversion of UHE photons (preshower effect), which significantly affects the subsequent longitudinal shower development. The conversion probability depends on photon energy and can be calculated accurately by QED. The comparison of the observed fraction of converted photon events to the expected one allows the determination of the absolute energy scale of the observed photon air showers and, thus, an energy calibration of the air shower experiment. We provide details of the method and estimate the accuracy that can be reached as a function of the number of observed photon showers. Already a very small number of UHE photons may help to test and fix the absolute energy scale. PMID:24785024

  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. Expected rates with mini-arrays for air showers

    NASA Technical Reports Server (NTRS)

    Hazen, W. E.

    1985-01-01

    As a guide in the design of mini-arrays used to exploit the Linsley effect in the study of air showers, it is useful to calculate the expected rates. The results can aid in the choice of detectors and their placement or in predicting the utility of existing detector systems. Furthermore, the potential of the method can be appraised for the study of large showers. Specifically, we treat the case of a mini-array of dimensions small enough compared to the distance of axes of showers of interest so that it can be considered a point detector. The input information is taken from the many previous studies of air showers by other groups. The calculations will give: (1) the expected integral rate, F(sigma, rho), for disk thickness, sigma, or rise time, t sub 1/2, with local particle density, rho, as a parameter; (2) the effective detection area A(N) with sigma (min) and rho (min) and rho (min) as parameters; (3) the expected rate of collection of data F sub L (N) versus shower size, N.

  4. Irregularity of the muon component in extensive air showers

    SciTech Connect

    Glushkov, A.V.; Makarov, I.T.; Nikiforova, E.S.

    1995-07-01

    Experimental data obtained from 1974 to 1992 at the Yakutsk array for muons with threshold energies E{sub {mu}} {ge} 1 GeV in extensive air showers (EAS) are analyzed. Periods of reliable detector operation are selected, and miscounts of muon detectors near their operation thresholds are thoroughly taken into account. Average lateral distribution functions (LDF) are obtained for EAS muons in the energy range E{sub 0} = 10{sup 17} - 5 x 10{sup 19} eV and in the zenith-angle range {theta}=0{degrees} - 60{degrees}. For energies E{sub 0} > 5 x 10{sup 18} eV, the LDF are shown to depend on E{sub 0} and {theta} in a substantially different manner than they do in the range of lower EAS energies. This irregularity is apparently associated with certain unknown processes or unknown primary particles involved in the development of EASs. 7 refs., 13 figs.

  5. Extensive air shower simulations with the CORSIKA program

    SciTech Connect

    Capdevielee, J.N.; Gabriel, P.; Gils, H.J.; Grieder, P.; Heck, D.; Knapp, J.; Mayer, H.J.; Oehlschlaeger, J.; Rebel, H.; Schatz, G.; Thouw, T. )

    1993-06-15

    CORSIKA is a detailed Monte Carlo program to study the development of extensive air showers in the atmosphere initiated by photons, protons, or nuclei of energies up to 10[sup 17] eV. Wherever possible experimentally accessible data have been used to model the high energy interactions of primary and secondary particles with the nuclei of the atmosphere. The CORSIKA code is based essentially on the Dual Parton Model to describe the hadronic interactions at high energies, the isobar model for hadronic reactions at low energies, and EGS4 for a detailed simulation of the electromagnetic part. The nucleus-nucleus interaction model follows the considerations of Klar and Huefner. Heuristic nucleus fragment models are implemented. Diffractive and charge exchange reactions are possible. Photoproduction of muon pairs and hadrons has been introduced into the electromagnetic part. The gross features of the program are presented and some results are given.

  6. Measurement of shower electrons and muons using a small air shower array

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    A small air shower array has been used to measure the size spectrum of air showers at sea level in the size range 6.10 to the 3rd power to 10 to the 6th power. The result fitted with the power law gives an index 2.79 + or - 0.11 for the differential spectrum. Lateral distribution of electrons fitted with the well known NKG function results in an age parameter s = 1.35 for core distances less than 30m and s = 0.8 for longer core distances. Lateral distribution of muons follows the general shape of Greisen's relation but is much higher in intensity. Muon and electron densities at the same observation point are also compared.

  7. 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.

  8. Radio Detection of Air Showers with LOFAR and AERA

    NASA Astrophysics Data System (ADS)

    Hörandel, Jörg R.

    Radio detection of extensive air showers is a new method to measure the properties of high-energy cosmic rays. Recent results are reviewed from the LOFAR radio telescope and the Auger Engineering Radio Array (AERA) at the Pierre Auger Observatory.

  9. 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.

  10. 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.

  11. 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.

  12. A new radiograpic method using electromagnetic component of air shower

    NASA Astrophysics Data System (ADS)

    Taketa, A.; Okubo, S.; Tanaka, H.

    2012-12-01

    We have developed a novel radiographic method to measure the density length with electromagnetic component of air shower. Air shower produced by a primary cosmic ray consists of muon component and electromagnetic component. Electromagnetic component is consists of electron, positron and photon. The penetration power of electromagnetic component is weaker than that of muon, so soft component is suitable for small scale structure thinner than 2 kg/cm^2 equivalent to 20m thick water, like buildings and small hills. But it requires particle identification which means distinguishing muon and electromagnetic component. Particle identification can be done with strong magnets and dense detectors, but it is very hard to use that kind of detector for radiography because of their weight and cost. We established the cheap and effective method to distinguish soft component and hard component statistically. We also performed measurements in Arimura observation vault of Mt. Sakurajima, Japan. As a result of this observation, we found there is an anti-correlation between soft component flux and rainfall. If the water content of the soil became larger, the amount of absorption increases. So this result can be interpreted as detecting the increase of the water content by soft component flux. This method can be applied for the quantitive compensation of the measurement data like absolute gravitymeter data and tiltmeter data which is easy to receive turbulence by rain. It is also expected that the quantitive compensation leads to the improvement in accuracy of diastrophism measurement and the improvement in presumed accuracy of magma movement inside a volcano.

  13. 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.

  14. Theory of fluctuations of extended air showers

    NASA Technical Reports Server (NTRS)

    Dedenko, L. G.

    1975-01-01

    The Monte Carlo method was used to calculate the probability distribution functions of shower characteristics for primary protons at sea level. The calculation was based on the following model of the elementary event: the interaction paths are 90 g/sq cm for nucleons and 120 g/sq cm for pions. The nonelasticity coefficient for nucleons is uniformly distributed between 0.1 and 0.9, and for pions it is equal to 1. Isobaric pions are taken into account. The spectra of secondary particles were determined using Cocconi's approximation formula. The calculation for the nuclei was carried out on the assumption of a breakup of the nucleus into component nucleons. The mean number of particles and the variances of the distributions for electrons when the number of muons was fixed, and for muons when the number of electrons was fixed, were calculated.

  15. A new way of air shower detection: measuring the properties of cosmic rays with LOFAR

    NASA Astrophysics Data System (ADS)

    Nelles, A.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Rachen, J. P.; Schellart, P.; Scholten, O.; ter Veen, S.; Thoudam, S.; Trinh, T. N. G.

    2015-08-01

    High-energy cosmic rays impinging onto the atmosphere of the Earth initiate cascades of secondary particles: extensive air showers. Many of the particles in a shower are electrons and positrons. During the development of the air shower and by interacting with the geomagnetic field, the electromagnetic cascade creates radiation, which we detect at frequencies of tens of MHz with the LOFAR radio telescope in the Netherlands. After many years of struggling to understand the emission mechanisms, the radio community has achieved the breakthrough. We are now able to determine direction, energy, and type of the shower- inducing primary particle from the radio measurements. The large number of antennas at LOFAR allows us to have a high precision and very detailed measurements. We will elaborate on the shower reconstruction, a precise description of the intensity of the radio signal at ground level (at frequencies from 10 to 240 MHz), a precise measurement of the shape of the radio wavefront, and on the reconstruction of the shower energy.

  16. Radio emission of extensive air showers at microwave frequencies

    NASA Astrophysics Data System (ADS)

    Filonenko, A. D.

    2016-05-01

    It is found that the power of the incoherent radiation of ionization electrons of an extensive air shower in the frequency range of 150 GHz is more than 10-24 W/m2Hz, with the shower energy ~1018 eV at a distance of 5 km from its axis. This means that, unlike fluorescent detectors, a radio telescope with an effective area of more than 300 m2 can monitor the trajectory of showers with an energy higher than 1018 eV at any time of the day regardless of the weather. The spectrum maximum near the frequency of 150 GHz is roughly three orders of magnitude higher than the value experimentally measured in the characteristic band (~5-10 GHz).

  17. 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.

  18. 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.

  19. Influence of the Landau-Pomeranchuk-Migdal effect on the features of extensive air showers

    SciTech Connect

    Kalmykov, N.N.; Ostapchenko, S.S.; Pavlov, A.I.

    1995-10-01

    The influence of the Landau-Pomeranchuk-Migdal (LPM) effect on the features of extensive air showers (EAS) is studied. The development of hadronic cascades is described in the quark-gluon string model. It is shown that the LPM effect does not exert a significant influence on EAS features up to energies of 10{sup 20} eV. 19 refs., 2 figs.

  20. Sub-luminal pulses from cosmic ray air showers

    NASA Astrophysics Data System (ADS)

    Linsley, J.

    1985-08-01

    Some of the signals produced by air showers in scintillators possess a distinctive feature, a sub-luminal pulse (SLP) following the normal one with a time delay of approximately 1.5 r/c. The average amplitude of the SLP corresponds to an energy deposit of about 50 MeV, three times as much as is deposited in a typical scintillator by vertical minimum ionizing muons. The SLP account for approximately 5% of the energy deposited in the atmosphere by IR showers with energy 10 to the 10th power GeV at impact parameters 1 km. Assuming that these pulses are due to neutrons travelling with a speed slightly less than c, they provide a unique means of estimating Eh, the energy deposited by slow hadrons, in showers of this very high energy. On the other hand, if not allowed for properly, these pulses are liable to cause errors in estimating the impact parameters of large showers from pulse width observations.

  1. Sub-luminal pulses from cosmic ray air showers

    NASA Technical Reports Server (NTRS)

    Linsley, J.

    1985-01-01

    Some of the signals produced by air showers in scintillators possess a distinctive feature, a sub-luminal pulse (SLP) following the normal one with a time delay of approximately 1.5 r/c. The average amplitude of the SLP corresponds to an energy deposit of about 50 MeV, three times as much as is deposited in a typical scintillator by vertical minimum ionizing muons. The SLP account for approximately 5% of the energy deposited in the atmosphere by IR showers with energy 10 to the 10th power GeV at impact parameters 1 km. Assuming that these pulses are due to neutrons travelling with a speed slightly less than c, they provide a unique means of estimating E sub h, the energy deposited by slow hadrons, in showers of this very high energy. On the other hand, if not allowed for properly, these pulses are liable to cause errors in estimating the impact parameters of large showers from pulse width observations.

  2. 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.

  3. Lateral and Time Distributions of Extensive Air Showers for CHICOS

    NASA Astrophysics Data System (ADS)

    Jillings, C. J.; Wells, D.; Chan, K. C.; Hill, J.; Falkowski, B.; Sepikas, J.

    2005-04-01

    We report results of a series of detailed Monte-Carlo calculations to determine the density and arrival-time distribution of charged particles in extensive air showers. We have parameterized both distributions as a function of distance from the shower axis, energy of the primary cosmic-ray proton, and incident zenith angle. Muons and electrons are parameterized separately. These parameterizations can be easily used in maximum-likelihood reconstruction of air showers. Calculations were performed for primary energies between 10^18 and 10^21eV and zenith angles out to approximately 50^o. The calculations are appropriate for the California High School Cosmic Ray Observatory: a 400 km^2 array of scintillation detectors in Los Angeles county. The average elevation of the array is approximately 250 meters above sea level. Currently 64 of 90 sites are operational. The array will be completed this year. We thank the NSF, the CURE program at the Jet Propulsion Laboratory, the SURF program at Caltech, and the Chinese University of Hong Kong.

  4. Considerations on the radio emission from extended air showers

    NASA Astrophysics Data System (ADS)

    Conti, E.; Sartori, G.

    2016-05-01

    The process of radio emission from extended air showers produced by high energy cosmic rays has reached a good level of comprehension and prediction. It has a coherent nature, so the emitted power scales quadratically with the energy of the primary particle. Recently, a laboratory measurement has revealed that an incoherent radiation mechanism exists, namely, the bremsstrahlung emission. In this paper we expound why bremsstrahlung radiation, that should be present in showers produced by ultra high energy cosmic rays, has escaped detection so far, and why, on the other side, it could be exploited, in the 1–10 GHz frequency range, to detect astronomical γ-rays. We propose an experimental scheme to verify such hypothesis, which, if correct, would deeply impact on the observational γ-ray astronomy.

  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. An universal description of the particle flux distributions in extended air showers

    SciTech Connect

    Chou, Aaron S.; Arisaka, Katsushi; Pernas, Maximo David Ave; Barnhill, David; Billoir, Pierre; Tripathi, Arun; Yamamoto, Tokonatsu; /Fermilab /UCLA /KICP, Chicago /Paris U., VI-VII

    2005-08-01

    It is shown that the electromagnetic and muonic fluxes in extended air showers (EAS) can be described using a simple model incorporating attenuation and geometrical dispersion. The model uses a reduced set of parameters including the primary energy E, the position of shower maximum X{sub max} relative to the ground, and a muon flux normalization N{sub {mu}}. To a good approximation, this set of three physical parameters is sufficient to predict the variability of the particle fluxes due to systematic differences between different models of composition and hadronic interactions, and due to statistical event-by-event differences in shower development. Measurements of these three physical observables are therefore unbiased and very nearly model-independent, in contrast with standard measurement techniques. The theoretical problem of determining primary composition is thus deconvolved from the measurement procedure, and may be approached in a subsequent analysis of the measured distributions of (E, X{sub max}, N{sub {mu}}).

  7. Performance of the Tibet II/HD air shower array

    NASA Astrophysics Data System (ADS)

    Amenomori, M.; Ayabe, S.; Caidong; Danzengluobu; Ding, L. K.; Feng, Z. Y.; Fu, Y.; Guo, H. W.; He, M.; Hibino, K.; Hotta, N.; Huang, J.; Huang, Q.; Huo, A. X.; Izu, K.; Jia, H. Y.; Kajino, F.; Kasahara, K.; Katayose, Y.; Kawata, K.; Labaciren; Li, J. Y.; Lu, H.; Lu, S. L.; Luo, G. X.; Meng, X. R.; Mizutani, K.; Mu, J.; Nanjo, H.; Nishizawa, M.; Ohnishi, M.; Ohta, I.; Ouchi, T.; Ozawa, S.; Peng, Z. R.; Ren, J. R.; Saito, T.; Sakata, M.; Sasaki, T.; Shi, Z. Z.; Shibata, M.; Shiomi, A.; Shirai, T.; Sugimoto, H.; Taira, K.; Tan, Y. H.; Tateyama, N.; Torii, S.; Utsugi, T.; Wang, C. R.; Wang, H.; Xu, X. W.; Yamamoto, Y.; Yu, G. C.; Yuan, A. F.; Yuda, T.; Zhang, C. S.; Zhang, H. M.; Zhang, J. L.; Zhang, N. J.; Zhang, X. Y.; Zhaxiciren; Zhaxisangzhu

    2001-04-01

    Tibet II Air Shower Array consisting of scintillation counters with lattice of 15 m spacing has been operated with very high trigger rate of about 200 Hz. The threshold enegy of this array is estimated to be about 8 TeV for proton induced showers. Tibet High Density (HD) Array with 7.5 m spacing has been operated with the trigger rate of 115 Hz. The Mode energy of this array is estimated to be about 3 TeV for proton showers. Angular resolution of the arrays are estimated to be 0.9 degree above 10 TeV for Tibet II array, and 0.85 degree above TeV for HD array, resepectively. The angular resolution of these arrays and other array performances are examined by observing the Moon shadow resulting from the cosmic ray deficit in the direction of the Moon. Using the deflection of the Moon shadow to the east-west direction, the error of the array can be estimated by observing the displacement of the shadow in the north-south direction, because it is free from the effect of geomagnetic field, especially at Yangbajing in Tibet. The calibrations such as primary energy, angular resolution and pointing errors, directly using the Moon shadow has first been done by the Tibet experiment..

  8. Air shower arrival directions measured at Buckland Park

    NASA Technical Reports Server (NTRS)

    Gerhardy, P. R.; Prescott, J. R.; Protheroe, R. J.; Clay, R. W.; Patterson, J. R.; Gregory, A. G.

    1985-01-01

    The Buckland Park air shower array was operated for 3 years from 1979 to 1981 particularly for the study of anisotropies in the region of the knee of the size spectrum. The array which has been described in detail elsewhere was situated at a latitude of 35 S and had an effective size threshold of approx 3 x 10 to the 5th power particles (approx 3 x 10 to the 15th power Ev for vertical showers). A number of results from this experiment have already been published including anisotropy analyses (Gerhardy and Clay, 1983) and searches for very high energy gamma ray sources. The final distribution of measured shower arrival directions are presented here. These 1.3 x 10 to the 5th power events were selected as indicated in detail in Gerhardy and Clay (1983) and were essentially those events with well measured arrival directions. They are the same data set used in the above reference but no complete sky map has previously been presented.

  9. Probing Atmospheric Electric Fields through Radio Emission from Cosmic-Ray-Induced Air Showers

    NASA Astrophysics Data System (ADS)

    Scholten, Olaf; Trinh, Gia; Buitink, Stijn; Corstanje, Arthur; Ebert, Ute; Enriquez, Emilio; Falcke, Heino; Hoerandel, Joerg; Nelles, Anna; Schellart, Pim; Rachen, Joerg; Rutjes, Casper; ter Veen, Sander; Rossetto, Laura; Thoudam, Satyendra

    2016-04-01

    Energetic cosmic rays impinging on the atmosphere create a particle avalanche called an extensive air shower. In the leading plasma of this shower electric currents are induced that generate coherent radio wave emission that has been detected with LOFAR, a large and dense array of simple radio antennas primarily developed for radio-astronomy observations. Our measurements are performed in the 30-80 MHz frequency band. For fair weather conditions the observations are in excellent agreement with model calculations. However, for air showers measured under thunderstorm conditions we observe large differences in the intensity and polarization patterns from the predictions of fair weather models. We will show that the linear as well as the circular polarization of the radio waves carry clear information on the magnitude and orientation of the electric fields at different heights in the thunderstorm clouds. We will show that from the measured data at LOFAR the thunderstorm electric fields can be reconstructed. We thus have established the measurement of radio emission from extensive air showers induced by cosmic rays as a new tool to probe the atmospheric electric fields present in thunderclouds in a non-intrusive way. In part this presentation is based on the work: P. Schellart et al., Phys. Rev. Lett. 114, 165001 (2015).

  10. The Air-Shower Experiment KASCADE-Grande

    NASA Astrophysics Data System (ADS)

    Haungs, A.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; KASCADE-Grande Collaboration

    2009-12-01

    KASCADE-Grande is an extensive air shower experiment at the Forschungszentrum Karlsruhe, Germany. Main parts of the experiment are the Grande array spread over an area of 700×700 m, the original KASCADE array covering 200×200 m with unshielded and shielded detectors, and additional muon tracking devices. This multi-detector system allows to investigate the energy spectrum, composition, and anisotropies of cosmic rays in the energy range up to 1 EeV. An overview on the performance of the apparatus and first results will be given.

  11. A search for microwave emission from cosmic ray air showers

    NASA Astrophysics Data System (ADS)

    Williams, Christopher Lee

    At the highest energies, the sources of cosmic rays should be among the most powerful extragalactic accelerators. Large observatories have revealed a flux suppression above a few 1019 eV, similar to the expected effect of the interaction of ultrahigh energy cosmic rays (UHECR) with the cosmic microwave background. The Pierre Auger Observatory has measured the largest sample of cosmic ray induced extensive air showers (EAS) at the highest energies leading to a precise measurement of the energy spectrum, hints of spatial anisotropy, and a surprising change in the chemical composition at the highest energies. To answer the question of the origin of UHECRs a larger sample of high quality data will be required to reach a statistically significant result. One of the possible techniques suggested to achieve this much larger data sample, in a cost effective way, is ultra-wide field of view microwave telescopes which would operate in an analogous way to the already successful fluorescence detection (FD) technique. Detecting EAS in microwaves could be done with 100% duty cycle and essentially no atmospheric effects. This presents many advantages over the FD which has a 10% duty cycle and requires extensive atmospheric monitoring for calibration. We have pursued both prototype detector designs and improved laboratory measurements, the results of which are reported herein, and published in (Alvarez-Muniz et al., 2013; Alvarez-Muniz et al., 2012a; Williams et al., 2013; Alvarez-Muniz et al., 2013). The Microwave Detection of Air Showers (MIDAS) experiment is the first ultra-wide field of view imaging telescope deployed to detect isotropic microwave emission from EAS. With 61 days of livetime data operating on the University of Chicago campus we were able to set new limits on isotropic microwave emission from extensive air showers. The new limits rule out current laboratory air plasma measurements (Gorham et al., 2008) by more than five sigma. The MIDAS experiment continues to

  12. A transient digitiser for fast air shower events

    NASA Technical Reports Server (NTRS)

    Wild, N. R.; Clay, R. W.

    1985-01-01

    Air shower structure are often measured on time scales of a few nanoseconds. Longitudinal disk structure near the core is of the order of meters in dimension, air Cerenkov pulses have full widths at half maximum of the order of tens of nanoseconds, and fast timing over typical arrays is usually measured to nanosecond accuracy. oscilloscopes can be used but have very limited dynamic range and are expensive if measurements down to a few nanoseconds are to be made. For the fast Cerenkov work, an instrument with better dynamic range than an oscilloscope and with a time resolution sufficient to allow measurements limited only by system risetime of a few nanoseconds is needed. A 16/32 channel, 8 bit, fast transient digitizer was designed and built which runs at sample intervals down to approx. 1 nanosecond per channel.

  13. Combination of emulsion chamber and air shower array at Mt. Chacaltaya

    SciTech Connect

    Kawasumi, N.; Tsushima, I.; Honda, K.; Hashimoto, K. ); Matano, T. ); Mori, K.; Inoue, N.; Ticona, R. ); Ohsawa, A. ); Tamada, M. ); Martinic, N.; Aliaga, Z.; Reguerin, A.; Aguirre, C. )

    1993-06-15

    Data of 34 familes with the accompanying air showers, observed by the combination of emulsion chamber and air shower array at Mt. Chacaltaya, are presented. Comparison with the simulation calculation concludes that a change is necessary in the characteristics of hadron interactions in [ital E][sub 0][ge]10[sup 15] eV.

  14. Extensive Air Showers: from the muonic smoking guns to the hadronic backbone

    NASA Astrophysics Data System (ADS)

    Cazon, L.

    2013-06-01

    Extensive Air Showers are complex macroscopic objects initiated by single ultra-high energy particles. They are the result of millions of high energy reactions in the atmosphere and can be described as the superposition of hadronic and electromagnetic cascades. The hadronic cascade is the air shower backbone, and it is mainly made of pions. Decays of neutral pions initiate electromagnetic cascades, while the decays of charged pions produce muons which leave the hadronic core and travel many kilometers almost unaffected. Muons are smoking guns of the hadronic cascade: the energy, transverse momentum, spatial distribution and depth of production are key to reconstruct the history of the air shower. In this work, we overview the phenomenology of muons on the air shower and its relation to the hadronic cascade. We briefly review the experimental efforts to analyze muons within air showers and discuss possible paths to use this information.

  15. 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.

  16. 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.

  17. 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.

  18. First Experimental Characterization of Microwave Emission from Cosmic Ray Air Showers.

    PubMed

    Smída, R; Werner, F; Engel, R; Arteaga-Velázquez, J C; Bekk, K; Bertaina, M; Blümer, J; Bozdog, H; Brancus, I M; Chiavassa, A; Cossavella, F; Di Pierro, F; Doll, P; Fuchs, B; Fuhrmann, D; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Huber, D; Huege, T; Kampert, K-H; Kang, D; Klages, H; Kleifges, M; Krömer, O; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Mathys, S; Mayer, H J; Melissas, M; Morello, C; Neunteufel, P; Oehlschläger, J; Palmieri, N; Pekala, J; Pierog, T; Rautenberg, J; Rebel, H; Riegel, M; Roth, M; Salamida, F; Schieler, H; Schoo, S; Schröder, F G; Sima, O; Stasielak, J; Toma, G; Trinchero, G C; Unger, M; Weber, M; Weindl, A; Wilczyński, H; Will, M; Wochele, J; Zabierowski, J

    2014-11-28

    We report the first direct measurement of the overall characteristics of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the signals of the microwave antennas of the Cosmic-Ray Observation via Microwave Emission experiment have been read out and searched for signatures of radio emission by high-energy air showers in the GHz frequency range. Microwave signals have been detected for more than 30 showers with energies above 3×10^{16}  eV. The observations presented in this Letter are consistent with a mainly forward-directed and polarized emission process in the GHz frequency range. The measurements show that microwave radiation offers a new means of studying air showers at E≥10^{17}  eV. PMID:25494064

  19. 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.

  20. Radio detection of cosmic ray air showers in the digital era

    NASA Astrophysics Data System (ADS)

    Huege, Tim

    2016-03-01

    In 1965 it was discovered that cosmic ray air showers emit impulsive radio signals at frequencies below 100 MHz. After a period of intense research in the 1960s and 1970s, however, interest in the detection technique faded almost completely. With the availability of powerful digital signal processing techniques, new attempts at measuring cosmic ray air showers via their radio emission were started at the beginning of the new millennium. Starting with modest, small-scale digital prototype setups, the field has evolved, matured and grown very significantly in the past decade. Today's second-generation digital radio detection experiments consist of up to hundreds of radio antennas or cover areas of up to 17 km2. We understand the physics of the radio emission in extensive air showers in detail and have developed analysis strategies to accurately derive from radio signals parameters which are related to the astrophysics of the primary cosmic ray particles, in particular their energy, arrival direction and estimators for their mass. In parallel to these successes, limitations inherent in the physics of the radio signals have also become increasingly clear. In this article, we review the progress of the past decade and the current state of the field, discuss the current paradigm of the radio emission physics and present the experimental evidence supporting it. Finally, we discuss the potential for future applications of the radio detection technique to advance the field of cosmic ray physics.

  1. 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; 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; Smiałkowski, A; Smída, 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; Susa, 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; Veberic, 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

    2010-03-01

    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. PMID:20366976

  2. 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.

  3. Lateral distribution of high energy hadrons and gamma ray in air shower cores observed with emulsion chambers

    NASA Technical Reports Server (NTRS)

    Matano, T.; Machida, M.; Honda, K.; Hashimoto, K.; Navia, C. E.; Kawasumi, N.; Tsushima, I.; Matinic, N.; Aquirre, C.

    1985-01-01

    A high energy event of a bundle of electrons, gamma rays and hadronic gamma rays in an air shower core were observed. The bundles were detected with an emulsion chamber with thickness of 15 cm lead. This air shower is estimated to be initiated with a proton with energy around 10 to the 17th power to 10 to the 18th power eV at an altitude of around 100 gmc/2. Lateral distributions of the electromagnetic component with energy above 2 TeV and also the hadronic component of energy above 6 TeV of this air shower core were determined. Particles in the bundle are produced with process of the development of the nuclear cascade, the primary energy of each interaction in the cascade which produces these particles is unknown. To know the primary energy dependence of transverse momentum, the average products of energy and distance for various average energies of secondary particles are studied.

  4. Variation of the shower lateral spread with air temperature at the ground

    NASA Astrophysics Data System (ADS)

    Wilczyńska, B.; Engel, R.; Homola, P.; Keilhauer, B.; Klages, H.; Pękala, J.; Wilczyński, H.

    The vertical profile of air density at a given site varies considerably with time. Well understood seasonal differences are present, but sizeable effects on shorter time scales, like day to night or day to day variations, are also observed. In consequence, the Moliere radius changes, influencing the lateral distribution of particles in the air showers and therefore may influence the shower detection in surface detector arrays. In air shower reconstruction, usually seasonal average profiles of the atmosphere are used, because local daily measurements of the profile are rarely available. Therefore, the daily fluctuations of the atmosphere are not accounted for. This simplification increases the inaccuracies of shower reconstruction. We show that a universal correlation exists between the ground temperature and the shape of the atmospheric profile, up to altitudes of several kilometers, hence providing a method to reduce inaccuracies in shower reconstruction due to weather variation.

  5. Search for long-lived massive particles in extensive air showers

    NASA Technical Reports Server (NTRS)

    Kawamoto, M.; Inoue, N.; Misaki, Y.; Manabe, O.; Takeuchi, T.; Toyoda, Y.

    1985-01-01

    Air showers containing delayed sub-showers which may be produced by a long-lived massive particle have been investigated by using twelve detectors. Ten events have been selected out as the candidates. However, a definite conclusion cannot be reached at the present time.

  6. Radio emission from extensive air showers as a method for cosmic-ray detection

    SciTech Connect

    Kalmykov, N. N.; Konstantinov, A. A.; Engel, R.

    2010-07-15

    At the present time, radio emission from extensive air showers (EASs) is being considered as a new promising method for detecting cosmic rays of energy in the region E{sub 0} > 5 x 10{sup 16} eV. Radio emission from an EAS whose development is simulated by the Monte Carlo method is calculated here. The field of radio emission from an EAS is calculated on the basis of two representations of a shower: that as a set of individual particles and that as a continuous set of currents. The sensitivity of radio emission to EAS parameters in the frequency range 10-100 MHz is investigated. The results can be used to analyze experiments that being presently performed (CODALEMA and LOPES) and those that are being planned for the future.

  7. Searching for mini black holes signatures in cosmic rays air shower

    SciTech Connect

    Lamri, S.; Kalli, S.; Mimouni, J.

    2012-06-27

    Theories with extra dimensions at low Planck scale, offer the exciting possibility of mini black holes production in ultra high-energy particles interactions. In particular, cosmic neutrinos interaction can produce black holes deep in the Earth's atmosphere. These mini black holes then decay and produce 'characteristic' air showers. In this paper, we examine the properties of the mini black holes (mBH) air showers and compare them to the standard model (mSM) ones. We point out to some possible criteria that help distinguishing mBH air showers.

  8. 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.

  9. Crown detectors arrays to observe horizontal and upward air-showers

    NASA Astrophysics Data System (ADS)

    Fargion, D.; Grossi, M.; De Santis, M.; De Sanctis Lucentini, P. G.; Iori, M.; Sergi, A.; Moscato, F.

    Terrestrial Cerenkov Telescopes at tens GeV gamma energy and Scintillators set on a Crown-like array facing the Horizons may reveal far Cosmic Rays Showers or nearer PeVs Neutrino ν-e→W- shower in air as well as up-going ντ + N → τ + X, τ → Earth-Skimming tau air-showers. Even UHE SUSY χo+e→e˜→χo+e at tens PeVs-EeV energy may blaze at Horizons, as ν-e→W- shower. We show first estimate on down- and up-going Horizontal Showers traces for present and future Magic-like Crown Arrays and their correlated Scintillator-like twin Crown Arrays. The one mono- or stereo-Magic elements facing the Horizons are already comparable to present Amanda underground neutrino detector.

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    We reconstructed the energy and the position of the shower maximum of air showers with energies E gtrsim 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 Xmax 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 Xmax, this is the first direct experimental correlation of radio measurements with a different, established method. At the moment, the Xmax resolution of Tunka-Rex is approximately 40 g/cm2. 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.

  11. Formation of Carbon-Rich Grains in Air by Meteoritic Showers of Tke Nio and Chelyabinsk

    NASA Astrophysics Data System (ADS)

    Miura, Y.

    2015-07-01

    Carbon separation and concentration process can be formed at explosions of meteorite shower in air of the Nio (Japan) and Chelyabinsk (Russia) meteorites. Carbon concentration process by meteoritic explosions is an impact above terrestrial surface.

  12. 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.

  13. 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.

  14. 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.

  15. 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. PMID:25955053

  16. Simulation of anomalous extensive air showers initiated by strong neutrino-quark interactions

    SciTech Connect

    Mrenna, S. )

    1992-04-01

    The observation of extensive air showers (EAS) in the atmosphere initiated by ultrahigh-energy cosmic rays offers a test of new physics. In particular, some showers, initiated by neutral particles from point sources, contain a larger number of muons than can be explained by the standard model. A strong interaction between quarks and neutrinos, induced by some new physics, is presented as an explanation. For definiteness, the new physics is assumed to be the manifestation of a composite structure of quarks and leptons, though the general features of the interaction are common to many new physics scenarios. The consequences of such an interaction on the generation and development of EAS are studied with a phenomenological model incorporated into the Monte Carlo program SHOWERSIM. Properties of the electromagnetic, muonic, and hadronic components of simulated EAS for neutrino-induced and ordinary proton-induced showers are presented for the observation level of the CYGNUS experiment at Los Alamos. Some features of these components display distinctive signals of new physics.

  17. 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hildebrand, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; van Buren, J.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

    2009-07-01

    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 106 to 3×107GeV the attenuation length obtained increases from 170 to 210g/cm2. The experimental results are compared to predictions of simulations based on contemporary high-energy interaction models.

  20. 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.

  1. Muon Production Height investigated by the Air-Shower Experiment KASCADE-Grande

    NASA Astrophysics Data System (ADS)

    Doll, P.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, H.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; van Buren, J.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; KASCADE-Grande Collaboration

    2009-12-01

    A large area (128 m2) Muon Tracking Detector (MTD), located within the KASCADE experiment, has been built with the aim to identify muons ( E>0.8 GeV) and their directions in extensive air showers by track measurements under more than 18 r.l. shielding. The orientation of the muon track with respect to the shower axis is expressed in terms of the radial- and tangential angles. By means of triangulation the muon production height H is determined. By means of H, a transition from light to heavy cosmic ray primary particles with increasing shower energy E from 1-10 PeV is observed.

  2. 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.

  3. 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.

  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. Detection of Upward Air Showers with the EUSO Experiments

    NASA Technical Reports Server (NTRS)

    Takahashi, Y.; Hillman, L.; Zuccaro, Al; Adams, J.; Cline, D.

    2003-01-01

    Upward-going showers in the atmosphere can be detected by an orbiting satellite with appropriate instrumentation. If the method only uses directional Cherenkov radiation, it is difficult to discriminate the red shower events from the background noises of very short pulse. A spectroscopic polychromatic optical design can intentionally blur the focusing of photons at shorter wavelengths (300 - 330 nm), spreading the image size to 2 x 2 or 3 x 3 pixels. False triggers due to random chance coincidence of noises can be drastically reduced with a spectroscopic polychromatic, refractive telescope.

  6. Detection of Upward Air Showers with the EUSO Experiments

    NASA Astrophysics Data System (ADS)

    Takahashi, Y.; Hillman, L.; Zuccaro, A.; Adams, J.; Cline, D.; EUSO Collaboration

    2003-07-01

    Upward-going showers in the atmosphere can be detected by an orbiting satellite having an appropriate instrumentation. If the method only uses directional Cherenkov radiation, it is difficult to discriminate the real shower events from the background noises of very short pulse. A spectroscopic polychromatic optical design can intentionally blur the fo cusing of photons at shorter wavelengths (300 330 nm), spreading the image size to 2 × 2 or 3 × 3 pixels. False triggers due to random chance coincidence of noises can be drastically reduced with a spectroscopic polychromatic, refractive telescope.

  7. 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.

  8. Identifiability of UHE Gamma-ray Air Showers by Neural-Network-Analysis

    NASA Astrophysics Data System (ADS)

    Wada, Y.; Inoue, N.; Miyazawa, K.; Vankov, H.P.

    The chemical composition of Ultra-High-Energy (UHE) comic rays is one of unsolved mysteries, and its study will give us fruitful information on the origin and acceleration mechanism of UHE cosmic rays. Especially, a detection of UHE gamma-rays by hybrid experiments, such as AUGER and TA, will be a key to solve these questions. The characteristics of UHE gamma-ray showers have been studied on lateral and longitudinal structure of shower particles by AIRES and our own simulation code, so far. There are apparent differences in a slope of lateral distribution (Eta) and a depth of shower maximum (Xmax) between gamma-ray and proton induced showers because UHE gamma-ray showers are affected by the LPM effect and the geomagnetic cascading process in an energy region of > 1019.5eV. Different features between gamma-ray and proton showers are pointed out from the simulation study and an identifiability of gamma-ray showers from proton ones is also discussed by the method of Neural-Network-Analysis.

  9. Amplitude calibration of a digital radio antenna array for measuring cosmic ray air showers

    NASA Astrophysics Data System (ADS)

    Nehls, S.; Hakenjos, A.; Arts, M. J.; Blümer, J.; Bozdog, H.; van Cappellen, W. A.; Falcke, H.; Haungs, A.; Horneffer, A.; Huege, T.; Isar, P. G.; Krömer, O.

    2008-05-01

    Radio pulses are emitted during the development of air showers, where air showers are generated by ultra-high energy cosmic rays entering the Earth's atmosphere. These nano-second short pulses are presently investigated by various experiments for the purpose of using them as a new detection technique for cosmic particles. For an array of 30 digital radio antennas (LOPES experiment) an absolute amplitude calibration of the radio antennas including the full electronic chain of the data acquisition system is performed, in order to estimate absolute values of the electric field strength for these short radio pulses. This is mandatory, because the measured radio signals in the MHz frequency range have to be compared with theoretical estimates and with predictions from Monte Carlo simulations to reconstruct features of the primary cosmic particle. A commercial reference radio emitter is used to estimate frequency dependent correction factors for each single antenna of the radio antenna array. The expected received power is related to the power recorded by the full electronic chain. Systematic uncertainties due to different environmental conditions and the described calibration procedure are of order 20%.

  10. 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.

  11. Potentially pathogenic bacteria in shower water and air of a stem cell transplant unit.

    PubMed

    Perkins, Sarah D; Mayfield, Jennie; Fraser, Victoria; Angenent, Largus T

    2009-08-01

    Potential pathogens from shower water and aerosolized shower mist (i.e., shower aerosol) have been suggested as an environmental source of infection for immunocompromised patients. To quantify the microbial load in shower water and aerosol samples, we used culture, microscopic, and quantitative PCR methods to investigate four shower stalls in a stem cell transplant unit at Barnes-Jewish Hospital in St. Louis, MO. We also tested membrane-integrated showerheads as a possible mitigation strategy. In addition to quantification, a 16S rRNA gene sequencing survey was used to characterize the abundant bacterial populations within shower water and aerosols. The average total bacterial counts were 2.2 x 10(7) cells/liter in shower water and 3.4 x 10(4) cells/m(3) in shower aerosol, and these counts were reduced to 6.3 x 10(4) cells/liter (99.6% efficiency) and 8.9 x 10(3) cells/m(3) (82.4% efficiency), respectively, after membrane-integrated showerheads were installed. Potentially pathogenic organisms were found in both water and aerosol samples from the conventional showers. Most notable was the presence of Mycobacterium mucogenicum (99.5% identity) in the water and Pseudomonas aeruginosa (99.3% identity) in the aerosol samples. Membrane-integrated showerheads may protect immunocompromised patients from waterborne infections in a stem cell transplant unit because of efficient capture of vast numbers of potentially pathogenic bacteria from hospital water. However, an in-depth epidemiological study is necessary to investigate whether membrane-integrated showerheads reduce hospital-acquired infections. The microbial load in shower aerosols with conventional showerheads was elevated compared to the load in HEPA-filtered background air in the stem cell unit, but it was considerably lower than typical indoor air. Thus, in shower environments without HEPA filtration, the increase in microbial load due to shower water aerosolization would not have been distinguishable from

  12. The center of lateral iso-density contours for inclined cosmic air showers

    NASA Astrophysics Data System (ADS)

    Montanus, J. M. C.

    2016-02-01

    The horizontal lateral density of a cosmic air shower with a non-zero zenith angle is asymmetric. The asymmetry consist of a stretching of the iso-density contours to ellipses and to a shift of the center of the elliptic contours with respect to the core of the shower. The shift is caused by atmospheric attenuation. The modeling of the attenuation results in an equation for the shift as a function of zenith angle and the size of the iso-density contours. A more accurate equation is obtained by investigating the shift in lateral densities of simulated showers. It is shown how the shift can be incorporated in an elliptic lateral density function. A linear approximation for the shift allows for an analytical solution for the shifted elliptic density. Its predictions for the polar variations of the density are compared with data of simulated showers.

  13. Correlation of angular and lateral distributions of electrons in extensive air showers

    NASA Astrophysics Data System (ADS)

    Giller, Maria; Śmiałkowski, Andrzej; Legumina, Remigiusz

    2016-08-01

    The aim of this paper is to explain the weak correlation of the angular and lateral deflections of electrons in extensive air showers in the primary energy range 1016-1019 eV, when compared with that in some models of electron propagation. We derive analytical formulae for the correlation coefficient in the multiple scattering model with energy losses and show a strong role of the ionisation in diminishing the correlation. By considering a Heitler-like model of an electromagnetic cascade we show also that the presence of photons, parent to electrons, causes a decrease of the correlation, roughly explaining quantitatively the small correlation in air showers.

  14. Influence of atmospheric electric fields on the radio emission from extensive air showers

    NASA Astrophysics Data System (ADS)

    Trinh, T. N. G.; Scholten, O.; Buitink, S.; van den Berg, A. M.; Corstanje, A.; Ebert, U.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Köhn, C.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Rutjes, C.; Schellart, P.; Thoudam, S.; ter Veen, S.; de Vries, K. D.

    2016-01-01

    The atmospheric electric fields in thunderclouds have been shown to significantly modify the intensity and polarization patterns of the radio footprint of cosmic-ray-induced extensive air showers. Simulations indicated a very nonlinear dependence of the signal strength in the frequency window of 30-80 MHz on the magnitude of the atmospheric electric field. In this work we present an explanation of this dependence based on Monte Carlo simulations, supported by arguments based on electron dynamics in air showers and expressed in terms of a simplified model. We show that by extending the frequency window to lower frequencies, additional sensitivity to the atmospheric electric field is obtained.

  15. 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.

  16. 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.

  17. 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.

  18. 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. PMID:24344351

  19. Study of the extensive air shower mass sensitive parameters in prototype of ALBORZ array

    NASA Astrophysics Data System (ADS)

    Rastegarzadeh, G.; Nemati, M.

    2015-03-01

    In this work we have used muon production depth distribution as well as the lateral distribution of the secondary particles of Extensive Air Showers (EAS) as two main parameters to infer the mass composition of primary cosmic rays. In order to achieve a realistic estimate of the mass composition, a sample of showers initiated by proton and iron particles as primaries have been simulated by CORSIKA code with zenith angle between 0° and 18° and discrete energies in a range between 1014 and 1016 eV for ALBORZ (1200 m a.s.l, Tehran, Iran) and KASKADE (110 m a.s.l, Karlsruhe, Germany) observation levels. Moreover lateral density distribution functions of energy for charged particles of air showers have been proposed for both proton and Iron primaries. We have indicated that among these two EAS parameters, lateral distribution of secondary particles provides better mass discrimination.

  20. Radio emission of energetic cosmic ray air showers: Polarization measurements with LOPES

    NASA Astrophysics Data System (ADS)

    Lopes Collaboration; Isar, P. G.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Auffenberg, J.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huang, X.; Huege, T.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Over, S.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; LOPES Collaboration

    2009-06-01

    LOPES is a radio antenna array co-located with the Karlsruhe Shower Core and Array DEtector, KASCADE-Grande in Forschungszentrum Karlsruhe, Germany, which provides well-calibrated trigger information and air shower parameters for primary energies up to 10eV. By the end of 2006, the radio antennas were re-configured to perform polarization measurements of the radio signal of cosmic ray air showers, recording in the same time both, the East-West and North-South polarization directions of the radio emission. The main goal of these measurements is to reconstruct the polarization characteristics of the emitted signal. This will allow a detailed comparison with theoretical predictions. The current status of these measurements is reported here.

  1. Measurement of cosmic-ray air showers with the Tunka Radio Extension (Tunka-Rex)

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Tunka-Rex is a radio detector for cosmic-ray air showers in Siberia, triggered by Tunka-133, a co-located air-Cherenkov detector. The main goal of Tunka-Rex is the cross-calibration of the two detectors by measuring the air-Cherenkov light and the radio signal emitted by the same air showers. This way we can explore the precision of the radio-detection technique, especially for the reconstruction of the primary energy and the depth of the shower maximum. The latter is sensitive to the mass of the primary cosmic-ray particles. In this paper we describe the detector setup and explain how electronics and antennas have been calibrated. The analysis of data of the first season proves the detection of cosmic-ray air showers and therefore, the functionality of the detector. We confirm the expected dependence of the detection threshold on the geomagnetic angle and the correlation between the energy of the primary cosmic-ray particle and the radio amplitude. Furthermore, we compare reconstructed amplitudes of radio pulses with predictions from CoREAS simulations, finding agreement within the uncertainties.

  2. Weather induced effects on extensive air showers observed with the surface detector of the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Bleve, Carla

    The rate of events measured with the surface detector (SD) of the Pierre Auger Observatory is found to be modulated by the weather conditions. This effect, observed in different ranges of S(1000), the signal measured at 1000 m from the shower core, is due to the increasing amount of matter traversed by a shower as the ground pressure increases and to the inverse proportionality of the Moliere radius to the air density near ground. The latter effect results in a modulation of the lateral spread of the shower with T and P. Air- shower simulations with different realistic profiles of the atmosphere support this interpretation of the observed effects.

  3. Detailed studies of the electron lateral distribution in extensive air showers with energies around 10(16) eV

    NASA Technical Reports Server (NTRS)

    Dzikowski, T.; Wdowczyk, J.; Gawin, J.

    1984-01-01

    Detailed studies have been performed of the electron lateral distribution in extensive air showers using the Lodz extensive air shower array. The showers were grouped according to their particle densities around 20 m from the core. The grouping was made in very narrow intervals of the densities. For every group of showers and for every distance interval /changing by 5 m/ histograms of the numbers of electron counters discharged have been obtained. The trays of G.M counters were located at following distances from the center of the triggering detectors array: 16 m, 76 m, 117 m, 137 m, 141 m and 147 m.

  4. 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…

  5. Calibrating the absolute amplitude scale for air showers measured at LOFAR

    NASA Astrophysics Data System (ADS)

    Nelles, A.; Hörandel, J. R.; Karskens, T.; Krause, M.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Erdmann, M.; Falcke, H.; Haungs, A.; Hiller, R.; Huege, T.; Krause, R.; Link, K.; Norden, M. J.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; Schröder, F. G.; ter Veen, S.; Thoudam, S.; Trinh, T. N. G.; Weidenhaupt, K.; Wijnholds, S. J.; Anderson, J.; Bähren, L.; Bell, M. E.; Bentum, M. J.; Best, P.; Bonafede, A.; Bregman, J.; Brouw, W. N.; Brüggen, M.; Butcher, H. R.; Carbone, D.; Ciardi, B.; de Gasperin, F.; Duscha, S.; Eislöffel, J.; Fallows, R. A.; Frieswijk, W.; Garrett, M. A.; van Haarlem, M. P.; Heald, G.; Hoeft, M.; Horneffer, A.; Iacobelli, M.; Juette, E.; Karastergiou, A.; Kohler, J.; Kondratiev, V. I.; Kuniyoshi, M.; Kuper, G.; van Leeuwen, J.; Maat, P.; McFadden, R.; McKay-Bukowski, D.; Orru, E.; Paas, H.; Pandey-Pommier, M.; Pandey, V. N.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Röttgering, H.; Schwarz, D.; Serylak, M.; Sluman, J.; Smirnov, O.; Tasse, C.; Toribio, M. C.; Vermeulen, R.; van Weeren, R. J.; Wijers, R. A. M. J.; Wucknitz, O.; Zarka, P.

    2015-11-01

    Air showers induced by cosmic rays create nanosecond pulses detectable at radio frequencies. These pulses have been measured successfully in the past few years at the LOw-Frequency ARray (LOFAR) and are used to study the properties of cosmic rays. For a complete understanding of this phenomenon and the underlying physical processes, an absolute calibration of the detecting antenna system is needed. We present three approaches that were used to check and improve the antenna model of LOFAR and to provide an absolute calibration of the whole system for air shower measurements. Two methods are based on calibrated reference sources and one on a calibration approach using the diffuse radio emission of the Galaxy, optimized for short data-sets. An accuracy of 19% in amplitude is reached. The absolute calibration is also compared to predictions from air shower simulations. These results are used to set an absolute energy scale for air shower measurements and can be used as a basis for an absolute scale for the measurement of astronomical transients with LOFAR.

  6. A comparative study of the electron and photon components in photon-induced air showers

    NASA Astrophysics Data System (ADS)

    Di Sciascio, G.; D'Ettorre Piazzoli, B.; Iacovacci, M.

    1997-03-01

    A detailed simulation of the electromagnetic component of extensive air showers generated by 10 11-10 15 eV photons has been carried out by means of the EPAS code. We present and discuss the results concerning the longitudinal, lateral and temporal distributions of electrons and photons down to 1 MeV energy threshold.

  7. Test of the hadronic interaction model EPOS with KASCADE air shower data

    NASA Astrophysics Data System (ADS)

    Hörandel, J. R.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; KASCADE-Grande Collaboration

    2009-12-01

    Predictions of the hadronic interaction model EPOS 1.61 as implemented in the air shower simulation program CORSIKA are compared to observations with the KASCADE experiment. The investigations reveal that the predictions of EPOS are not compatible with KASCADE measurements. The discrepancies seen are most likely due to use of a set of inelastic hadronic cross sections that are too high.

  8. A test of the hadronic interaction model EPOS with air shower data

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Luczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; van Buren, J.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

    2009-03-01

    Predictions of the hadronic interaction model EPOS 1.61 as implemented in the air shower simulation program CORSIKA are compared to observations with the KASCADE experiment. The investigations reveal that the predictions of EPOS are not compatible with KASCADE measurements. The discrepancies seen are most likely due to use of a set of inelastic hadronic cross sections that are too high.

  9. A Statistical Method for Reconstructing the Core Location of an Extensive Air Shower

    NASA Astrophysics Data System (ADS)

    Hedayati Kh., H.; Moradi, A.; Emami, M.

    2015-09-01

    Conventional methods of reconstructing extensive air showers (EASs) depend on a lateral density function which itself depends on shower size, age parameter, and core location. In the fitting procedure of a lateral density function to surface array information, the only parameter whose initial value is essential is core location. In this paper, we describe a refined version of a statistical method which can be used to find the initial trial core location of EASs with better precision than the conventional methods. In this method, we use arrival time information of secondary particles for finding not only arrival direction, but also core location.

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

    SciTech Connect

    Aab, Alexander; et al.

    2014-08-08

    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.

  11. a Multiscale, Lacunarity and Neural Network Method for γ/h Discrimination in Extensive Air Showers

    NASA Astrophysics Data System (ADS)

    Pagliaro, A.; D'Anna, F.; D'Alí Staiti, G.

    2012-12-01

    This paper presents a new method for the identification of extensive air showers initiated by different primaries. The method uses the multiscale concept and is based on the analysis of multifractal behaviour and lacunarity of secondary particle distributions together with a properly designed and trained artificial neural network. The separation technique is particularly suited for being applied when the topology of the particle distribution in the shower front is as largely detailed as possible. In the present work the method is discussed and applied in the experimental framework of ARGO-YBJ, to obtain hadron to gamma primary separation. We show that the presented approach gives very good results, leading, in the 1 - 10 Tev energy range, to a clear improvement of the discrimination power with respect to the existing figures for extended shower detectors.

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

    SciTech Connect

    Collaboration: Pierre Auger Collaboration

    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.

  13. 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.

  14. The size dependence of the average transverse momentum of hadrons with respect to the shower axis direction in extensive air showers observed at sea level

    NASA Astrophysics Data System (ADS)

    Ashton, F.; Nejabat, H.

    The simplest way of studying whether the characteristics of a nucleon-nucleon interaction change with increasing energy is to observe whether the mean value of hadron energy at the orthogonal core distance depends on shower size. Ashton et al. (1977) used a high-energy hadron detector as a master trigger and measured the core position and shower size of any accompanying air shower; results showed that the average transverse momentum of hadrons with respect to the shower axis direction increases with shower size. These results are checked, but with the following experimental changes: (1) the master trigger is now either an electron density inner ring trigger or an electron density outer ring trigger of the Durham EAS array; (2) the orthogonal core distances between measured hadron interactions and the shower axis direction are found; and (3) the charged or neutral state of a sample of detected hadrons is determined. The previously obtained results are confirmed by the experiment, and a change in the character of the nucleon-nucleon interaction is indicated for energies greater than 2 x 10 to the 14th eV.

  15. 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.

  16. Composition of primary cosmic rays near the bend from a study of hadrons in air showers at sea level

    NASA Technical Reports Server (NTRS)

    Mincer, A. I.; Freudenreich, H. T.; Goodman, J. A.; Tonwar, S. C.; Yodh, G. B.; Ellsworth, R. W.; Berley, D.

    1985-01-01

    Data on hadrons in air showers arriving at sea level were studied to find sensitivity to primary cosmic ray composition. The rate of showers which satisfy minimum shower density and hadron energy requirements as well as the rate of showers containing hadrons delayed with respect to the electron shower front are compared to Monte Carlo simulations. The data on the rate of total triggers and delayed hadrons are compared to predicted rates for two models of primary composition. The data are consistent with models which require an increasing heavy nuclei fraction near 10 to the 15th power eV. The spectra which are consistent with the observed rate are also compared to the observed shower size spectrum at sea level and mountain level.

  17. Circular polarization of radio emission from air showers probes atmospheric electric fields in thunderclouds.

    NASA Astrophysics Data System (ADS)

    Gia Trinh, Thi Ngoc; Scholten, Olaf; Buitink, Stijn; Corstanje, Arthur; Ebert, Ute; Enriquez, Emilio; Falcke, Heino; Horandel, Jörg R.; Nelles, Anna; Schellart, Pim; Rachen, Jorg; Rossetto, Laura; Rutjes, Casper; ter Veen, Sander; Thoudam, Satyendra

    2016-04-01

    When a high-energy cosmic-ray particle enters the upper layer of the atmosphere, it generates many secondary high-energy particles and forms a cosmic-ray-induced air shower. In the leading plasma of this shower electric currents are induced that emit electromagnetic radiation. These radio waves can be detected with LOw-Frequency ARray (LOFAR) radio telescope. Events have been collected under fair-weather conditions as well as under atmospheric conditions where thunderstorms occur. For the events under the fair weather conditions the emission process is well understood by present models. For the events measured under the thunderstorm conditions, we observe a large fraction of the circular polarization near the core of the shower which is not shown in the events under the fair-weather conditions. This can be explained by the change of direction of the atmospheric electric fields with altitude. Therefore, measuring the circular polarization of radio emission from cosmic ray extensive air showers during the thunderstorm conditions helps to have a better understanding about the structure of atmospheric electric fields in the thunderclouds.

  18. Tunka-Rex: the Cost-Effective Radio Extension of the Tunka Air-Shower Observatory

    NASA Astrophysics Data System (ADS)

    Schröder, F. G.; Bezyazeekov, P.; Budnev, N. M.; Gress, O. A.; Haungs, A.; Hiller, R.; Huege, T.; Kazarina, Y.; Kleifges, M.; Konstantinov, E. N.; Korosteleva, E. E.; Kostunin, D.; Krömer, O.; Kuzmichev, L. A.; Mirgazov, R. R.; Pankov, L.; Prosin, V. V.; Rubtsov, G. I.; Savinov, V.; Wischnewski, R.; Zagorodnikov, A.

    Tunka-Rex is the radio extension of the Tunka cosmic-ray observatory in Siberia close to Lake Baikal. Since October 2012 Tunka-Rex measures the radio signal of air-showers in coincidence with the non-imaging air-Cherenkov array Tunka-133. Furthermore, this year additional antennas will go into operation triggered by the new scintillator array Tunka-Grande measuring the secondary electrons and muons of air showers. Tunka-Rex is a demonstrator for how economic an antenna array can be without losing significant performance: we have decided for simple and robust SALLA antennas, and we share the existing DAQ running in slave mode with the PMT detectors and the scintillators, respectively. This means that Tunka-Rex is triggered externally, and does not need its own infrastructure and DAQ for hybrid measurements. By this, the performance and the added value of the supplementary radio measurements can be studied, in particular, the precision for the reconstructed energy and the shower maximum in the energy range of approximately 1017-1018 eV. Here we show first results on the energy reconstruction indicating that radio measurements can compete with air-Cherenkov measurements in precision. Moreover, we discuss future plans for Tunka-Rex.

  19. 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.

  20. 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.

  1. Longitudinal evolution of extensive air showers according to the results of Cherenkov-light studies

    SciTech Connect

    Kalmykov, N.N.; Khristiansen, G.B.; Prosin, V.V.

    1995-09-01

    The results of an analysis of the longitudinal evolution of Extensive Air Showers (EAS) with the aid of experimental recording the space-time structure of shower-induced Cherenkov radiation with the Yakutsk and Samarkand arrays are summarized. The combined data from these experiments make it possible to obtain the energy dependence of the mean depth of the EAS maximum in the wide energy range 3 x 10{sup 15} - 5 x 10{sup 17} eV, the shape of the mean cascade curve, and the depth distribution of EAS maxima at E{sub 0} = 10{sup 16} eV. The cross section for the inelastic interaction of 10{sup 16}-eV protons with the nuclei of air atoms is estimated. 14 refs., 8 figs.

  2. 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; Ó Murchadha, Aongus; Scholten, Olaf

    2016-02-01

    We discuss the radio emission from high-energy cosmic-ray induced air showers hitting Earth's surface before the cascade has died out in the atmosphere. The induced emission gives rise to a radio signal which should be detectable in the currently operating Askaryan radio detectors built to search for the GZK neutrino flux in ice. The in-air emission, the in-ice emission, as well as a new component, the coherent transition radiation when the particle bunch crosses the air-ice boundary, are included in the calculations.

  3. 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.

  4. 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

    2016-04-01

    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. PMID:27104694

  5. A NEW METHOD FOR FINDING CORE LOCATIONS OF EXTENSIVE AIR SHOWERS

    SciTech Connect

    Hedayati Kh, H.; Anvari, A.; Bahmanabadi, M.; Samimi, J.; Khakian Ghomi, M.

    2011-02-01

    Analysis of an extensive air shower (EAS) detected by surface arrays highly depends on the determination of core locations. Here we present a new method to find the core location of an EAS that, unlike the common methods, does not depend on the lateral distribution function and uses arrival times of secondary particles. This method improves the accuracy of finding the core location of a low-energy EAS in the internal parts of an array, in comparison with common methods.

  6. On the possible common nature of double extensive air showers and aligned events

    SciTech Connect

    Yakovlev, V. I.

    2012-07-15

    Double extensive air showers and aligned events at energies in the region E Greater-Than-Or-Equivalent-To 10{sup 16} eV were discovered more than a quarter of a century ago. However, there is still no satisfactory explanation of their nature. In the present study, it is assumed that these two types of events have common nature, stemming from the break of a string that arises in the interaction of ultrahigh-energy particles.

  7. 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.

  8. Design, development, and operation of a zero gravity shower

    NASA Technical Reports Server (NTRS)

    Middleton, R. L.; Krupnick, A. C.; Reily, J. C.; Schrick, B. J.

    1974-01-01

    The high mission penalty associated with water and electrical power usage constrained the shower configuration concept for the Skylab project to a procedure in which water is sprayed on the body to wet down and soaping is accomplished without water flow. The soap is then finally rinsed off. Initial concept confirmation tests are discussed along with details of the flight shower configuration, the shower water bottle, the shower stall assembly, the liquid-gas separator, the collection box and bag assembly, the hydrophobic filter assembly, and the soap dispenser. Aspects of microbial evaluation of flight qualification hardware are also considered.

  9. Radio signal correlation at frequency 32 MHz with extensive air showers parameters using Yakutsk array data

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    Study of cosmic rays properties by measuring the radio emission generated by charged particles of extensive air showers may be an alternative method to traditional methods that use large areas of the arrays. The arrays are consist hundreds and thousands of scintillation detectors for registration of charged particles, or consist detectors, recording emission generated by relativistic particles of EAS in the optical wavelength range. Such arrays are very costly because of a large amount of detectors and complex technical equipment. On the other hand, radio method is much cheaper and easier to operate with nearly 100% duty cycle. It is sufficient to have the antenna field and a simple radio receiver tuned to a given frequency. The main problem is to choose a noise free frequency range. For this purpose, in Yakutsk was installed and started radio array for EAS radio emission. The array consists crossed antennas oriented E - W and N - S. Air shower radio registration is conducted at a frequency of 32 MHz, free from industrial noise. Yakutsk Radio Array operates since 2008. Data obtained during those several seasons includes showers with energy above 1019 eV.

  10. Simultaneous observation of extensive air showers and deep-underground muons at the Gran Sasso Laboratory

    SciTech Connect

    Bellotti, R.; Cafagna, F.; Caliccio, M.; De Cataldo, G.; De Marzo, C.; Erriquez, O.; Favuzzi, C.; Giglietto, N.; Nappi, E.; Spinelli, P. ); Cecchini, S.; Fabbri, M.; Giacomelli, G.; Mandrioli, G.; Matteuzzi, P.; Pal, B.; Patrizii, L.; Predieri, F.; Sanzani, G.L.; Serra, P.; Spurio, M. ); Ahlen, S.; Ficenec, D.; Hazen, E.; Klein, S.; Levin, D.; Marin, A.; Stone, J.L.; Sulak, L.R.; Worstell, W. ); Barish, B.; Coutu, S.; Hong, J.; Liu, G.; Peck, C.; Solie, D.; Steele, J. ); Lane, C.; Steinberg, R. ); Battistoni, G.; Bilokon, H.; Bloise, C.; Campana, P.; Chiarella, V.; Forti, C.; Grillo, A.; Iarocci, E.; Marini, A.; Patera, V.; Re; MACRO Collaboration

    1990-09-01

    Combined measurements of extensive air showers at the surface and high-energy muons deep underground have been initiated at the Gran Sasso Laboratory. The underground detector is the first supermodule of MACRO (area=140 m{sup 2}, depth=3100 m of water equivalent , {ital E}{sub {mu}}{gt}1.3 TeV) and the surface detector is the EAS-TOP array (altitude 2000 m above sea level, total enclosed area {ital A}{approximately}10{sup 5} m{sup 2}). We discuss the correlation technique, the comparison between the shower parameters as determined by the two detectors, and some of the characteristics of the reconstructed events.

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

    NASA Technical Reports Server (NTRS)

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

    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.

  12. 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.

  13. 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.)).

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

    DOE PAGESBeta

    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

  15. Measurements of the muon content of air showers at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Valiño, I.; Pierre Auger Collaboration

    2015-08-01

    The Pierre Auger Observatory offers a unique window to study cosmic rays and particle physics at energies above 3 EeV (corresponding to a centre-of-mass energy of 75 TeV in proton-proton collisions) inaccessible to accelerator experiments. We discuss the different methods of estimating the number of muons in showers recorded at the Pierre Auger Observatory, which is an observable sensitive to primary mass composition and to properties of the hadronic interactions in the shower. The muon content, derived from data with these methods, is presented and compared to predictions from the post-LHC hadronic interaction models for different primary composition. We find that models do not reproduce well the Auger observations, displaying a deficit of muons at the ground. In the light of these results, a better understanding of ultra-high energy extensive air showers and hadronic interactions is crucial to determine the composition of ultra-high energy cosmic rays. We report on the upgrade plans of the Pierre Auger Observatory to achieve this science goal.

  16. Interpretation of the depths of maximum of extensive air showers measured by the Pierre Auger Observatory

    SciTech Connect

    Collaboration: Pierre Auger Collaboration

    2013-02-01

    To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize those two observables as functions of the first two moments of the ln A distribution. We examine the goodness of this simple method through simulations of test mass distributions. The application of the parameterization to Pierre Auger Observatory data allows one to study the energy dependence of the mean ln A and of its variance under the assumption of selected hadronic interaction models. We discuss possible implications of these dependences in term of interaction models and astrophysical cosmic ray sources.

  17. GLE Observations in 23rd Solar Cycle at the Baksan Air Shower Arrays Andyrchy and Carpet

    NASA Astrophysics Data System (ADS)

    Karpov, S. N.; Alekseenko, V. V.; Djappuev, D. D.; Karpova, Z. M.; Khaerdinov, N. S.; Petkov, V. B.; Radchenkov, A. V.; Zaichenko, A. N.

    2003-07-01

    Total counting rates of two Baksan extensive air shower arrays Andyrchy and Carp et were examined during 10 Ground Level Enhancements (GLE) of Solar Cosmic Rays (SCR) observed in current 23rd cycle of solar activity. In this case the threshold primary energy is equal to geomagnetic cut-off, Emin = 5.8 GeV. Significant increases (>3 st.dev.) above the galactic cosmic ray background were found during 6 GLE events from 10. The amplitudes of all increases make the tenth shares of percent. Therefore, they can not be registered by neutron monitors with a close geomagnetic cut-off.

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    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.

  19. Atmospheric effects and sidereal-diurnal variations in extended air showers

    NASA Technical Reports Server (NTRS)

    Efimov, N. N.; Krasilnikov, D. D.; Nikolskiy, S. N.; Shamsutdinova, F. K.

    1975-01-01

    Observations are presented on the variations of extended air shower intensity with an average power of 1.4 x 10,000 and 1.4 x 100,000 particles at sea level. The effect of disintegrating particles and the essential role of cascades formed above the lower third of the atmosphere are examined. However, the authors failed to discover anisotropy of initial particles with an energy of 10 to the 14th power to 10 to the 15th power eV with an accuracy of up to 0.1%.

  20. 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.

  1. Measurement of arrival time of particles in extensive air showers using TDC32

    NASA Astrophysics Data System (ADS)

    Gupta, S. K.; Christiansen, J.; Hayashi, Y.; Jain, A.; Mohanty, P. K.; Ravindran, K. C.; Satyanarayana, B.

    2013-04-01

    Arrival time of particles in an extensive air shower (EAS) is a key physical parameter to determine its direction. EAS direction is useful for studies of anisotropy and composition of cosmic rays, and search for multi-TeV γ-rays sources. Accurate timing may be used to search exotic phenomena such as production of new particles at extremely high energies available during early stages of development of EAS and also for detecting sub-relativistic hadrons in EAS. Time to digital converters (TDCs) are used to perform this task. Traditional TDCs operate in the START-STOP mode with limited dynamic range and single-hit capability. With the advent of high luminosity collider LHC, need for TDCs with large dynamic range, multi-hit capability and TRIGGERED mode of operation became necessary. A 32 channel TDC was designed for the GRAPES-3 experiment on a CAMAC platform around TDC32, an ASIC developed by micro-electronics group at CERN, Geneva. Four modules were operated in the GRAPES-3 experiment. Here, we present details of the circuit design and their performance over several years. The multi-hit feature of this device was used to study the time structure of particles in the EAS on time scale of ~1 μs. The distribution of time intervals in the multi-hit data shows an exponential profile with a time constant of ~370 ns. These delayed particles are likely to be neutrons produced in the EAS core that were recorded in the scintillator detectors following the relativistic EAS front.

  2. Measurement of the cosmic-ray energy spectrum above 1016 eV with the LOFAR Radboud Air Shower Array

    NASA Astrophysics Data System (ADS)

    Thoudam, S.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; ter Veen, S.; Trinh, T. N. G.; van Kessel, L.

    2016-01-01

    The energy reconstruction of extensive air showers measured with the LOFAR Radboud Air Shower Array (LORA) is presented in detail. LORA is a particle detector array located in the center of the LOFAR radio telescope in the Netherlands. The aim of this work is to provide an accurate and independent energy measurement for the air showers measured through their radio signal with the LOFAR antennas. The energy reconstruction is performed using a parameterized relation between the measured shower size and the cosmic-ray energy obtained from air shower simulations. In order to illustrate the capabilities of LORA, the all-particle cosmic-ray energy spectrum has been reconstructed, assuming that cosmic rays are composed only of protons or iron nuclei in the energy range between ˜2 × 1016 and 2 × 1018 eV. The results are compatible with literature values and a changing mass composition in the transition region from a Galactic to an extragalactic origin of cosmic rays.

  3. Measuring a Cherenkov ring in the radio emission from air showers at 110-190 MHz with LOFAR

    NASA Astrophysics Data System (ADS)

    Nelles, A.; Schellart, P.; Buitink, S.; Corstanje, A.; de Vries, K. D.; Enriquez, J. E.; Falcke, H.; Frieswijk, W.; Hörandel, J. R.; Scholten, O.; ter Veen, S.; Thoudam, S.; van den Akker, M.; Anderson, J.; Asgekar, A.; Bell, M. E.; Bentum, M. J.; Bernardi, G.; Best, P.; Bregman, J.; Breitling, F.; Broderick, J.; Brouw, W. N.; Brüggen, M.; Butcher, H. R.; Ciardi, B.; Deller, A.; Duscha, S.; Eislöffel, J.; Fallows, R. A.; Garrett, M. A.; Gunst, A. W.; Hassall, T. E.; Heald, G.; Horneffer, A.; Iacobelli, M.; Juette, E.; Karastergiou, A.; Kondratiev, V. I.; Kramer, M.; Kuniyoshi, M.; Kuper, G.; Maat, P.; Mann, G.; Mevius, M.; Norden, M. J.; Paas, H.; Pandey-Pommier, M.; Pietka, G.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Röttgering, H.; Scaife, A. M. M.; Schwarz, D.; Smirnov, O.; Stappers, B. W.; Steinmetz, M.; Stewart, A.; Tagger, M.; Tang, Y.; Tasse, C.; Vermeulen, R.; Vocks, C.; van Weeren, R. J.; Wijnholds, S. J.; Wucknitz, O.; Yatawatta, S.; Zarka, P.

    2015-05-01

    Measuring radio emission from air showers offers a novel way to determine properties of the primary cosmic rays such as their mass and energy. Theory predicts that relativistic time compression effects lead to a ring of amplified emission which starts to dominate the emission pattern for frequencies above ∼ 100 MHz. In this article we present the first detailed measurements of this structure. Ring structures in the radio emission of air showers are measured with the LOFAR radio telescope in the frequency range of 110-190 MHz. These data are well described by CoREAS simulations. They clearly confirm the importance of including the index of refraction of air as a function of height. Furthermore, the presence of the Cherenkov ring offers the possibility for a geometrical measurement of the depth of shower maximum, which in turn depends on the mass of the primary particle.

  4. 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.

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

    DOE PAGESBeta

    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

  6. 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.

  7. Study of single and combined mass-sensitive observables of cosmic ray induced extensive air showers

    NASA Astrophysics Data System (ADS)

    Rastegarzadeh, G.; Nemati, M.

    2016-03-01

    In this study, combinations of the global arrival time, (Δτ_{global}), pseudorapidity, and lateral density distribution (ρ_{μ}) of muons, which are three mass-sensitive observables of cosmic ray induced extensive air showers, have been used as new parameters to study the primary mass discrimination around the knee energies (100 TeV-10 PeV). This is a simulation-based study and the simulations have been performed for the KASCADE array at Karlsruhe and the Alborz-I array at Tehran to study the effect of the altitude on the quality of the primary mass discrimination. The merit factors of the single and combined three mass-sensitive observables have been calculated to compare the discrimination power of combined and single observables. We have used the CORSIKA 7.4 code to simulate the extensive air showers (EASs) sample sets. Considering all aspects of our study, it is found that the ratio of the global time to the lateral density distribution of the muons gives better results than other ratios; also in the case of single observables, the muon density gives better results compared with the other observables. Also it is shown that below 1 PeV primary energies, the ratio of the muon global time to the muon density (Δτ_{global}/ρ_{μ}) results in a better mass discrimination relative to the muon density only.

  8. 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.

  9. Astrophysical and structural peculiarities of extensive air showers with energy E{sub 0} {>=} 10{sup 17} eV from Yakutsk EAS array data

    SciTech Connect

    Glushkov, A. V. Pravdin, M. I.

    2006-12-15

    The astrophysical characteristics of primary cosmic rays (PCRs) and the structure of extensive air showers (EASs) with energy E{sub 0} {>=} 10{sup 17} eV are simultaneously analyzed using the Yakutsk EAS array data acquired in the period 1974-2005. Enhanced and reduced particle fluxes are shown to come from the disk of the Supergalaxy (the Local Supercluster of galaxies) at E{sub 0} {>=} 5 x 10{sup 18} eV and E{sub 0} {<=} (2-3) x 10{sup 18}, respectively. The development of air showers with E{sub 0} {>=} (3-5) x 10{sup 18} eV differs significantly from that at lower energies. This is interpreted as a manifestation of the possible interaction between extragalactic PCRs and the matter of this spatial structure.

  10. COMPARING THE ENERGY SPECTRA OF ULTRAHIGH ENERGY COSMIC RAYS MEASURED WITH EXTENSIVE AIR SHOWER ARRAYS

    SciTech Connect

    Ivanov, A. A.

    2010-03-20

    The energy spectra of ultrahigh energy cosmic rays (CRs) measured with giant extensive air shower (EAS) arrays exhibit discrepancies between the flux intensities and/or estimated CR energies exceeding experimental errors. The well-known intensity correction factor due to the dispersion of the measured quantity in the presence of a rapidly falling energy spectrum is insufficient to explain the divergence. Another source of systematic energy determination error is proposed concerning the charged particle density measured with the surface arrays, which arises due to simplifications (namely, the superposition approximation) in nucleus-nucleus interaction description applied to the shower modeling. Making use of the essential correction factors results in congruous CR energy spectra within experimental errors. Residual differences in the energy scales of giant arrays can be attributed to the actual overall accuracy of the EAS detection technique used. CR acceleration and propagation model simulations using the dip and ankle scenarios of the transition from galactic to extragalactic CR components are in agreement with the combined energy spectrum observed with EAS arrays.

  11. Measurement of muon production depth in cosmic ray induced extensive air showers by time structure of muons at observation level

    NASA Astrophysics Data System (ADS)

    Rastegarzadeh, Gohar; Khoshabadi, Sahar

    2016-04-01

    In the present work, muon production depth (MPD) of extensive air showers (EASs) are measured from time structure of muons at the observation level. A new method for calculating MPD is presented. Based on its relation to the maximum depth of development of electrons and muons (Xmax and Xmaxμ), this parameter has been used as a mass discriminator factor. Using CORSIKA simulation, different simulations for proton and iron primaries in the energy range of 1014-1015 eV are presented. It is found that MPD distribution is strongly related to Xmax and Xmaxμ. These are mass sensitive parameters and their potential as mass discriminator parameters between light and heavy primaries for ALBORZ prototype array and some arbitrary arrays are investigated.

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

    PubMed

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

    2004-10-01

    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. PMID:15524863

  13. Prediction of Lightning Inception by Large Ice Particles and Extensive Air Showers.

    PubMed

    Dubinova, Anna; Rutjes, Casper; Ebert, Ute; Buitink, Stijn; Scholten, Olaf; Trinh, Gia Thi Ngoc

    2015-07-01

    We derive that lightning can start if the electric field is 15% of the breakdown field, and if elongated ice particles of 6 cm length and 100 free electrons per cm3 are present. This is one particular example set from a parameter range that we discuss as well. Our simulations include the permittivity ε(ω) of ice. 100 free electrons per cm3 exist at 5.5 km altitude in air showers created by cosmic particles of at least 5×10(15)  eV. If the electric field zone is 3 m high and 0.2  km2 in the horizontal direction, at least one discharge per minute can be triggered. The size distribution of the ice particles is crucial for our argument; more detailed measurements would be desirable. PMID:26182101

  14. 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.

  15. Light Transmission Fluctuations from Extended Air Showers Produced by Cosmic-Rays and Gamma-Rays

    NASA Astrophysics Data System (ADS)

    Taylor, Stuart

    Cosmic-ray and gamma-ray experiments that use the atmosphere as a calorimeter, such as the High Resolution Fly's Eye (HiRes) and the Telescope Array (TA), require understanding the transmission of the light from the air shower of particles produced by the cosmic-ray or gamma-ray striking the atmosphere. To better understand the scattering and transmission of light to the detectors, HiRes measures light from different calibrated sources. We compare scattered light from laser shots a few kilometers away from the two HiRes detectors with direct light from stable portable light sources placed a few meters in front of the phototubes. We use two HiRes detectors to study and isolate contributions to fluctuations of the measured light. These contributions include fluctuations in the source intensity, the night sky background, scattering and transmission of the laser beam, the phototubes and electronics, and photostatistics. N o rth Mirror Fields of View

  16. Neural Chip SAND in online data processing of extensive air showers

    NASA Astrophysics Data System (ADS)

    Eppler, W.; Fischer, T.; Gemmeke, H.; Chilingarian, A.; Vardanyan, A.

    2000-04-01

    The neural chip SAND (Simple Applicable Neural Device) was designed to accelerate computations of neural networks at a very low cost basis, due to the fact that only few peripheral chips are necessary to use the neural network chip in applications. Four SAND-chips were implemented on one PCI-board. The board is highly usable for hardware triggers in particle physics. The performance of a SAND-PCI-board is 800 Mega Connections per Second due to four neuro-chips, each with four parallel 16 bit multipliers and 40 bit adders. SAND is able to implement feedforward neural networks with a maximum of 512 input neurons and three hidden layers. Kohonen feature maps and radial basis function networks may be also calculated. The application of the SAND-PCI-board is proposed for cosmic ray physics to allow online analysis of extensive air showers.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Evidence for the charge-excess contribution in air shower radio emission observed by the CODALEMA experiment

    NASA Astrophysics Data System (ADS)

    Bellétoile, A.; Dallier, R.; Lecacheux, A.; Marin, V.; Martin, L.; Revenu, B.; Torres, D.

    2015-09-01

    CODALEMA is one of the pioneer experiments dedicated to the radio detection of ultra high energy cosmic rays (UHECR), located at the radio observatory of Nançay (France). The CODALEMA experiment uses both a particle detector array and a radio antenna array. Data from both detection systems have been used to determine the ground coordinates of the core of extensive air showers (EAS). We discuss the observed systematic shift of the core positions determined with these two detection techniques. We show that this shift is due to the charge-excess contribution to the total radio emission of air showers, using the simulation code SELFAS. The dependences of the radio core shift to the primary cosmic ray characteristics are studied in details. The observation of this systematic shift can be considered as an experimental signature of the charge excess contribution.

  2. Measurements of the Depth of Maximum of Air-Shower Profiles at the Pierre Auger Observatory and their Composition Implications

    NASA Astrophysics Data System (ADS)

    de Souza, V.

    We describe how the analysis of air showers detected by the Pierre Auger Observatory leads to an accurate determination of the depth of maximum (Xmax). First, the analysis of the air-shower which leads to the reconstruction of Xmax is discussed. The properties of the detector and its measurement biases are treated and carefully taken into consideration. The Xmax results are interpreted in terms of composition, where the interpretation depends mainly on the hadronic interaction models. A global fit of the Xmax distribution yields an estimate of the abundance of four primaries species. The analysis represents the most statistically significant composition information ever obtained for energies above 1017.8 eV. The scenario that emerges shows no support for a strong flux of iron nuclei and a strong energy dependence of the proton fraction.

  3. Cosmic ray energy reconstruction from the S(500) observable recorded in the KASCADE-Grande air shower experiment

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2016-04-01

    The energy reconstruction at KASCADE-Grande is based on a combination of the shower size and the total muon number, which are both estimated for each individual air shower event. We present investigations where we employed a second method to reconstruct the primary energy using S(500), which are the charged particle densities inferred with the KASCADE-Grande detector at a distance of 500 m from the shower axis. We considered the attenuation of inclined showers by applying the "Constant Intensity Cut" method and we employed a simulation-derived calibration to convert the recorded S(500) into primary energy. We observed a systematic shift in the S(500)-derived energy compared with previously reported results obtained using the standard reconstruction technique. However, a comparison of the two methods based on simulated and measured data showed that this shift only appeared in the measured data. Our investigations showed that this shift was caused mainly by the inadequate description of the shape of the lateral density distribution in the simulations.

  4. Reestimation of the energy of extensive air showers at the Yakutsk EAS array with the CORSIKA package

    NASA Astrophysics Data System (ADS)

    Glushkov, A. V.; Pravdin, M. I.; Saburov, A. V.

    2014-06-01

    The responses of ground and underground muon scintillation detectors of the Yakutsk extensive air shower (EAS) array from primary particles with the energy E 0 ≥ 1017 eV have been calculated within the QGSJET-01-d, QGSJET-II-04, SIBILL, and EPOS-LHC models with the CORSIKA package. A new estimate obtained for E 0 is lower by a factor of about 1.41 than that previously obtained within the calorimetric method for EASs.

  5. Simulation study on number of secondary particles in extensive air showers using CORSIKA code

    SciTech Connect

    Halataei, S. M. H.; Bahmanabadi, M.; Samimi, J.; Ghomi, M. Khakian

    2008-04-15

    We have simulated more than 10{sup 5} extensive air showers (EAS) by CORSIKA code, with a proton as the primary particle. The range of energy for primary particles was selected from 50 TeV to 5 PeV, with differential flux given by dN/dE{proportional_to}E{sup -2.7}. Using the secondary charged particles produced of these EASs, we obtained the function dN{sub sp}({theta},X)/d{theta}, where N{sub sp}({theta},X) is the number of secondary charged particles in EASs as a function of atmosphere depth, X, and zenith angle, {theta}. A sin{theta}cos{sup n(X)}{theta} distribution was obtained for zenith angle distribution of the number of secondary charged particles, where power index, n(X), is a function of atmosphere depth, X. We obtained n(X)=3.02+0.003XlnX-8.28x10{sup -9}X{sup 3}-1.35lnX. We have compared our results with the experimental data of various observatories.

  6. The current status of the GRAPES-3 extensive air shower experiment

    NASA Astrophysics Data System (ADS)

    Gupta, S. K.; Antia, H. M.; Dugad, S. R.; Goswami, U. D.; Hayashi, Y.; Iyer, A.; Ito, N.; Jagadeesan, P.; Jain, A.; Karthikeyan, S.; Kawakami, S.; Minamino, M.; Mohanty, P. K.; Morris, S. D.; Nayak, P. K.; Nonaka, T.; Oshima, A.; Rao, B. S.; Ravindran, K. C.; Tanaka, H.; Tonwar, S. C.; Grapes-3 Collaboration

    2009-12-01

    The GRAPES-3 is a dense extensive air shower array operating with ˜400 scintillator detectors and it also contains a 560 m 2 tracking muon detector ( E>1 GeV), at Ooty in India. 25% of scintillator detectors are instrumented with two fast photomultiplier tubes (PMTs) for extending the dynamic range to ˜5×10 particles m -2 . The scintillators, signal processing electronics and data recording systems were fabricated in-house to cut costs and optimize performance. The muon multiplicity distribution of the EAS is used to probe the composition of primary cosmic rays below the 'knee', with an overlap with direct measurements. Search for multi-TeV γ-rays from point sources is done with the aid of the muon detector. A good angular resolution of 0.7° at 30 TeV, is measured from the shadow of the Moon on the isotropic flux of cosmic rays. A sensitive limit on the diffuse flux of 100 TeV γ-rays is placed by using muon detector to filter the charged cosmic ray background. A tracking muon detector allows sensitive measurements on coronal mass ejections and solar flares through Forbush decrease events. We have major expansion plans to enhance the sensitivity of the GRAPES-3 experiment in the areas listed above.

  7. Light Transmission From Extended Air Showers Produced By Cosmic-Rays and Gamma-Rays

    NASA Astrophysics Data System (ADS)

    Taylor, S. F.; Abu-Zayyad, T.; Belov, K.; Cao, Z.; Chen, G.; Jui, C. C. H.; Kieda, D. B.; Matthews, J. N.; Salamon, M.; Sokolsky, P. V.; Smith, J. D.; Sommers, P.; Springer, R. W.; Stokes, B. T.; Thomas, S. B.; Wiencke, L. R.; Matthews, J. A. J.; Clay, R. W.; Dawson, B. R.; Simpson, K.; Bells, J.; Boyer, J.; Knapp, B.; Song, B. H.; Zhang, X. Z.; SDSS Collaboration; High Resolution Fly's Eye Collaboration; Telescope Array/U. Tokyo Collaboration

    1999-05-01

    Cosmic-ray and gamma-ray experiments that use the atmosphere as a calorimeter, such as the High Resolution Fly's Eye (HiRes) and the Telescope Array (TA), require understanding the transmission of the light from the air shower of particles produced by the cosmic-ray or gamma-ray striking the atmosphere. To better understand the scattering and transmission of light to the detectors, HiRes measures light from different calibrated sources. We compare scattered light from laser shots a few kilometers away from the two HiRes detectors, with direct light from stable portable light sources placed a few meters in front of the phototubes. We use two HiRes detectors to study and isolate contributions to fluctuations of the measured light. These contributions include fluctuations in the source intensity, the night sky background, scattering and transmission of the laser beam, the phototubes and electronics, and photostatistics. The High Resolution Fly's Eye Collaboration gratefully acknowledges the support of the US National Science Foundation, DOE, the US Army's Dugway Proving Grounds, and the support of our member universities.

  8. Minimal Prospects for Radio Detection of Extensive Air Showers in the Atmosphere of Jupiter

    NASA Astrophysics Data System (ADS)

    Bray, J. D.; Nelles, A.

    2016-07-01

    One possible approach for detecting ultra-high-energy cosmic rays and neutrinos is to search for radio emission from extensive air showers created when they interact in the atmosphere of Jupiter, effectively utilizing Jupiter as a particle detector. We investigate the potential of this approach. For searches with current or planned radio telescopes we find that the effective area for detection of cosmic rays is substantial (∼3 × 107 km2), but the acceptance angle is so small that the typical geometric aperture (∼103 km2 sr) is less than that of existing terrestrial detectors, and cosmic rays also cannot be detected below an extremely high threshold energy (∼1023 eV). The geometric aperture for neutrinos is slightly larger, and greater sensitivity can be achieved with a radio detector on a Jupiter-orbiting satellite, but in neither case is this sufficient to constitute a practical detection technique. Exploitation of the large surface area of Jupiter for detecting ultra-high-energy particles remains a long-term prospect that will require a different technique, such as orbital fluorescence detection.

  9. 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.

  10. 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. PMID:15902250

  11. 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.

  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. Investigating the extensive air shower properties: Tackling the challenges of the next generation cosmic ray observatory with the CODALEMA experiment

    NASA Astrophysics Data System (ADS)

    Martin, Lilian

    2014-04-01

    Our knowledge on ultra-high energy cosmic rays and their underlying sources and acceleration mechanisms is steadily improving thanks to the large observatories nowadays in operation. However the need for a next generation instrument is emerging from their experimental limitations and the scientific questions currently out of reach within a reasonable time line. Within this scope, the main features of the radio detection of extensive air showers are investigated and confronted to these challenging requirements. CODALEMA is the last experiment currently running in Europe dedicated to the cosmic ray detection using the observation of its induced radio electric field. The latest experimental upgrade and the synthesis of its operation features and the upcoming technical developments are presented. The main results of CODALEMA will be presented with special emphasis put on some of the new aspects of the data analysis offered by the CODALEMA3 autonomous station array. Finally, the opportunities provided by the Nançay observatory for efficient R&D activities and especially the upcoming technical developments are listed.

  14. 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.

  15. Investigating the Cherenkov light lateral distribution function for primary proton and iron nuclei in extensive air showers

    NASA Astrophysics Data System (ADS)

    Al-Rubaiee, A. A.; Hashim, U.; Al-Douri, Y.

    2015-11-01

    The lateral distribution function (LDF) of Cherenkov radiation in extensive air showers (EAS) was simulated by CORSIKA program for the conditions of Yakutsk Cherenkov array at the high energy range (1013-1016) eV for two primary particles (p and Fe) for different zenith angles. By depending on Breit-Wigner function for analyzing of Cherenkov light LDF, a parameterization of Cherenkov light LDF was reconstructed by depending on CORSIKA simulation as a function of primary energy. The comparison between the estimated Cherenkov light LDF with the LDF that measured on the Yakutsk EAS array gives the ability of particle identification that initiated the shower and determination of particle's energy around the knee region. The extrapolation of approximated Cherenkov light LDF for energies 20 and 30 PeV was obtained for primary particles (p and Fe).

  16. Reconstruction of the energy and depth of maximum of cosmic-ray air showers from LOPES radio measurements

    NASA Astrophysics Data System (ADS)

    Apel, W. D.; Arteaga-Velazquez, 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.; Fuhrmann, D.; 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.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Zabierowski, J.; Zensus, J. A.; Lopes Collaboration

    2014-09-01

    LOPES is a digital radio interferometer located at Karlsruhe Institute of Technology (KIT), Germany, that measures radio emission from extensive air showers at MHz frequencies in coincidence with KASCADE-Grande. In this article, we explore a method (slope method) that leverages the slope of the measured radio lateral distribution to reconstruct crucial attributes of primary cosmic rays. First, we present an investigation of the method on the basis of pure simulations. Second, we directly apply the slope method to LOPES measurements. Applying the slope method to simulations, we obtain uncertainties on the reconstruction of energy and depth of shower maximum (Xmax) of 13% and 50 g /cm2, respectively. Applying it to LOPES measurements, we are able to reconstruct energy and Xmax of individual events with upper limits on the precision of 20%-25% for the primary energy and 95 g /cm2 for Xmax, despite strong human-made noise at the LOPES site.

  17. The maximum depth of shower with E sub 0 larger than 10(17) eV on average characteristics of EAS different components

    NASA Technical Reports Server (NTRS)

    Pravdin, M. I.; Glushkov, A. V.; Efimov, N. N.; Makarov, I. T.; Dedenko, L. G.

    1985-01-01

    The extensive air shower (EAS) development model independent method of the determination of a maximum depth of shower (X sub m) is considered. X sub m values obtained on various EAS parameters are in a good agreement.

  18. 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.

  19. 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.

  20. Arrival time distributions of electrons in air showers with primary energies above 10 (18)eV observed at 900m above sea level

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    Detection of air showers with primary energies above 10 to the 19th power eV with sufficient statistics is extremely important in an astrophysical aspect related to the Greisen cut off and the origin of such high energy cosmic rays. Recently, a method is proposed to observe such giant air showers by measuring the arrival time distributions of air-shower particles at large core distances with a mini array. Experiments to measure the arrival time distributions of muons were started in 1981 and those of electrons in early 1983 in the Akeno air-shower array (930 gcm cm squared atmospheric depth, 900m above sea level). During the time of observation, the detection area of the Akeno array was expanded from 1 sq km to sq km in 1982 and to 20 sq km in 1984. Now the arrival time distribution of electrons and muons can be measured for showers with primary energies above 1019eV at large core distances.

  1. Development, Construction, and Content Validation of a Questionnaire to Test Mobile Shower Commode Usability

    PubMed Central

    Theodoros, Deborah G.; Russell, Trevor G.

    2015-01-01

    Background: Usability is an emerging domain of outcomes measurement in assistive technology provision. Currently, no questionnaires exist to test the usability of mobile shower commodes (MSCs) used by adults with spinal cord injury (SCI). Objective: To describe the development, construction, and initial content validation of an electronic questionnaire to test mobile shower commode usability for this population. Methods: The questionnaire was constructed using a mixed-methods approach in 5 phases: determining user preferences for the questionnaire’s format, developing an item bank of usability indicators from the literature and judgement of experts, constructing a preliminary questionnaire, assessing content validity with a panel of experts, and constructing the final questionnaire. Results: The electronic Mobile Shower Commode Assessment Tool Version 1.0 (eMAST 1.0) questionnaire tests MSC features and performance during activities identified using a mixed-methods approach and in consultation with users. It confirms that usability is complex and multidimensional. The final questionnaire contains 25 questions in 3 sections. The eMAST 1.0 demonstrates excellent content validity as determined by a small sample of expert clinicians. Conclusion: The eMAST 1.0 tests usability of MSCs from the perspective of adults with SCI and may be used to solicit feedback during MSC design, assessment, prescription, and ongoing use. Further studies assessing the eMAST’s psychometric properties, including studies with users of MSCs, are needed. PMID:25762862

  2. 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.

  3. Detection of reflected Cherenkov light from extensive air showers in the SPHERE experiment as a method of studying superhigh energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Antonov, R. A.; Aulova, T. V.; Bonvech, E. A.; Galkin, V. I.; Dzhatdoev, T. A.; Podgrudkov, D. A.; Roganova, T. M.; Chernov, D. V.

    2015-01-01

    Although a large number of experiments were carried out during the last few decades, the uncertainty in the spectrum of all nuclei of primary cosmic rays (PCRs) with superhigh energies is still high, and the results of many experiments on nuclear composition of PCRs are contradictory. An overview of the SPHERE experiment on detecting Vavilov-Cherenkov radiation from extensive air shower (EAS) reflected from a ground snow surface is given. A number of experimental studies implementing this method are presented and their results are analyzed. Some other popular methods of studying PCRs with superhigh energies ( E 0 > 1015 eV) and their main advantages and drawbacks are briefly considered. The detecting equipment of the SPHERE-2 experiment and the technique of its calibration are considered. The optical properties of snow, which are important for experiments on reflected Cherenkov light (CL) from EAS, are discussed and the history of observing reflected EAS CL is described. The algorithm of simulating the detector response and calculating the fiducial acceptance of shower detection is described. The procedure of processing the experimental data with a subsequent reconstruction of the spectrum of all PCR nuclei and analysis of the mass composition is shown. The first results of reconstructing the spectrum and separating groups of cosmic-ray nuclei with high energies in the SPHERE-2 experiment are presented. Main sources of systematic errors are considered. The prospects of developing the technique of observation of reflected EAS CL in future experiments are discussed.

  4. On the production mechanism of radio-pulses from large extensive air showers

    NASA Technical Reports Server (NTRS)

    Datta, P.; Pathak, K. M.

    1985-01-01

    None of the theories put forward so far to explain the radio emission from cosmic ray showers, has been successful in giving a satisfactory explanation for all the experimental data obtained from various laboratories over the globe. It is apprehended that emission mechanism at low and high frequencies may be quite different. This calls for new theoretical look into the phenomenon. Theoretical as well as the experimental results indicate that the frequency spectrum is rather flat in the frequency range (40 to 60 MHz. Above 80 MHz, the radio emission can be explained with the help of geomagnetic mechanism. But at very low frequency ( 10 MHz), mechanisms other than geomagnetic are involved.

  5. Results from the CACTI experiment: Air-Cerenkov and particle measurements of PeV air showers at Los Alamos

    SciTech Connect

    Paling, S.; Hillas, A.M.; Berley, D.

    1997-07-01

    An array of six wide angle Cerenkov detectors was constructed amongst the scintillator and muon detectors of the CYGNUS II array at Los Alamos National Laboratory to investigate cosmic ray composition in the PeV region through measurements of the shape of Cerenkov lateral distributions. Data were collected during clear, moonless nights over three observing periods in 1995. Estimates of depths of shower maxima determined from the recorded Cerenkov lateral distributions align well with existing results at higher energies and suggest a mixed to heavy composition in the PeV region with no significant variation observed around the knee. The accuracy of composition determination is limited by uncertainties in the expected levels of depth of maximum predicted using different Monte-Carlo shower simulation models.

  6. Monte Carlo simulations of electron lateral distributions in the core region of 10(13) - 10(16) eV air showers

    NASA Technical Reports Server (NTRS)

    Ash, A. G.

    1985-01-01

    This paper contains details of computer models of shower development which have been used to investigate the experimental data on shower cores observed in the Leeds 35 sq m and Sacramento Peak (New Mexico) 20 sq m arrays of current limited spark (discharge) chambers. The simulations include predictions for primaries ranging from protons to iron nuclei (with heavy nuclei treated using both superposition and fragmentation models).

  7. Consequences of parton saturation and string percolation on the development of cosmic ray showers.

    PubMed

    Pajares, C; Sousa, D; Vázquez, R A

    2001-02-26

    At high gluon or string densities, gluon saturation or the strong interaction among strings, either forming color ropes or giving rise to string percolation, induces a strong suppression in the particle multiplicities produced at high energy. This suppression implies important modifications on cosmic ray shower development. In particular, it is shown that it affects the depth of maximum, the elongation rate, and the behavior of the number of muons at energies about 10(17)--10(18) eV. The existing cosmic ray data point out in the same direction. PMID:11290221

  8. Study of Cherenkov Light Lateral Distribution Function Around the Knee Region in Extensive Air Showers

    NASA Astrophysics Data System (ADS)

    Al-Rubaiee, A.; Hashim, U.; Marwah, M.; Al-Douri, Y.

    2015-06-01

    The Cherenkov light lateral distribution function (LDF) was simulated with the CORSIKA code in the energy range (10^{13} - 10^{16}) eV. This simulation was performed for conditions and configurations of the Tunka EAS Cherenkov array for the two primary particles (p and Fe). Basing on the simulated results, many approximated functions are structured for two primary particles and different zenith angles. This allowed us to reconstruct the EAS events, which is, to determine the type and energy of the primary particles that produced showers from signal amplitudes of Cherenkov radiation measured by the Tunka Cherenkov array experiment. Comparison of the calculated LDF of Cherenkov radiation with that measured at the Tunka EAS array shows the ability to identify the primary particle that initiated the EAS cascades by determining its primary energy around the knee region of the cosmic ray spectrum.

  9. 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)

  10. The relation between the lateral profile of giant extensive air showers and the age parameter

    NASA Astrophysics Data System (ADS)

    Capdevielle, Jean-Noël; Cohen, Fabrice

    2005-05-01

    After performing extensive simulations with the code CoRSiKa, we have obtained an analytical description fitting with surprising accuracy the numerical densities up to distances larger than 5 km from the shower axis. This was achieved by using the hypergeometric formalism in place of the traditional NKG approach. The difficulty of cascade theory (validity limited to 3.5 Moliere radii), underlined with reason by the particle data group, is solved here, after overcoming the constraints of approximation B, to show that the distribution of lateral profiles at large distances is also correlated with the age parameter. This is an important step for a coherent interpretation of hybrid events recorded with both surface array and fluorescence telescopes, even with other information coming from Cerenkov or radio emission. A set of hypergeometric Gaussian functions, with a consistent relation between age parameter and total size, is proposed in the ultra-high-energy range (above 1 EeV) for electrons, muons and vertical equivalent muons.

  11. Geometric structures in hadronic cores of extensive air showers observed by KASCADE

    SciTech Connect

    Antoni, T.; Glasstetter, R.; Hoerandel, J.R.; Roth, M.; Apel, W.D.; Badea, F.; Bekk, K.; Bozdog, H.; Daumiller, K.; Doll, P.; Engel, R.; Engler, J.; Fessler, F.; Gils, H.J.; Haungs, A.; Heck, D.; Klages, H.O.; Maier, G.; Mathes, H.J.; Mayer, H.J.

    2005-04-01

    The geometric distribution of high-energy hadrons {>=}100 GeV in shower cores measured with the KASCADE calorimeter is analyzed. The data are checked for sensitivity to hadronic interaction features and indications of new physics as discussed in the literature. The angular correlation of the most energetic hadrons and, in particular, the fraction of events with hadrons being aligned are quantified by means of the commonly used parameter {lambda}{sub 4}. The analysis shows that the observed {lambda}{sub 4} distribution is compatible with that predicted by simulations and is not linked to an angular correlation from hadronic jet production at high energy. Another parameter, d{sub 4}{sup max}, describing distances between hadrons measured in the detector, is found to be sensitive both to the transverse momenta in secondary hadron production and the primary particle type. Transverse momenta in high-energy hadron interactions differing by a factor two or more from what is assumed in the standard simulations are disfavored by the measured d{sub 4}{sup max} distribution.

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

    SciTech Connect

    Aab, A.; et al.

    2014-12-31

    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.

  13. Particle distributions in approximately 10(14) 10(16) eV air shower cores at sea level

    NASA Technical Reports Server (NTRS)

    Hodson, A. L.; Ash, A. G.; Bull, R. M.

    1985-01-01

    Experimental evidence is reported for fixed distances (0, 1.0, 2.5 and 4.0 m) from the shower centers and for core flattening. The cores become flatter, on average, as the shower size (primary energy) increases. With improved statistics on 4192 cores, the previous results are exactly confirmed.

  14. Air Cargo Marketing Development

    NASA Technical Reports Server (NTRS)

    Kersey, J. W.

    1972-01-01

    The factors involved in developing a market for air cargo services are discussed. A comparison is made between the passenger traffic problems and those of cargo traffic. Emphasis is placed on distribution analyses which isolates total distribution cost, including logistical costs such as transportation, inventory, materials handling, packaging, and processing. Specific examples of methods for reducing air cargo costs are presented.

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

    DOE PAGESBeta

    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

  16. 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.

  17. 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. PMID:27367377

  18. 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.

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

    DOE PAGESBeta

    Aab, Alexander

    2016-06-14

    Here, 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 cascademore » 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.« less

  20. 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. PMID:26151172

  1. 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.

  2. 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.

  3. Research-Based Development of a Lesson Plan on Shower Gels and Musk Fragrances Following a Socio-Critical and Problem-Oriented Approach to Chemistry Teaching

    ERIC Educational Resources Information Center

    Marks, Ralf; Eilks, Ingo

    2010-01-01

    A case is described of the development of a lesson plan for 10th grade (age range 15-16) chemistry classes on the chemistry of shower gels. The lesson plan follows a socio-critical and problem-oriented approach to chemistry teaching. This means that, aside from learning about the basic chemistry of the components making up modern shower gels in…

  4. Ashra (All-sky Survey High Resolution Air-shower detector)Current Status on Mauna Loa, Hawai`i

    NASA Astrophysics Data System (ADS)

    Hamilton, John; Fox, R. A.; Sasaki, M.; Asaoka, Y.; Ashra Collaboration

    2008-09-01

    Now in its third year of on-site activities, Ashra is commencing full testing of its array of Cherenkov and Nitrogen Fluorescence detectors. The All-sky Survey High Resolution Air-shower detector is located on the northern upper slopes of Mauna Loa at the 11,000 ft elevation level. Utilizing a clear view of 80% of the sky and an unobstructed view of Mauna Kea, anglular resolution of 1.2 arcmin, sensitive to the blue to UV light with the use of image intensifier and CMOS technology, Ashra is in a unique position for studying the sources of High Energy Cosmic Ray sources (GRB, etc) as well as potential observations of earth-grazing neutrino interactions. 2004 saw the successful deployment of a prototype detector on Haleakala, with confirmed detection of several GRBs. Since the summer of 2005, steady progress was made in constructing and installation of detectors and their weather-proofed housings. UH-Hilo undergraduate students provided summer interns for this international collaboration between ICRR Univ. Tokyo, Univ. Hawai`i-Hilo, Univ Hawai`i-Manoa, Ibaraki Univ., Toho Univ. Chiba Univ., Kanagawa Univ., Nagoya Univ. & Tokyo Institute of Technology.

  5. 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.

  6. 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.

  7. Nonpotable reuse: Development of health criteria and technologies for shower water recycle. (Reannouncement with new availability information)

    SciTech Connect

    Burrows, W.D.; Schmidt, M.O.; Carnevale, R.M.; Schaub, S.A.

    1991-12-31

    The U.S. Army is evaluating recycle of field shower water as a conservation practice in arid regions and is seeking to define appropriate technologies and health criteria. Shower wastewaters at a military installation have been characterized in terms of physical, chemical and microbiological parameters. Two treatment technologies havebeen investigated. Microfiltration cartridges with a nominal pore size of 0.2 MU m achieved consistent removals of 75 15% of total organic carbon (TOC) and better than 99% of turbidity from synthetic shower water containing 50 to 100 mg/L of TOC as soap. An alternative treatmenttechnology utilized powered activated carbon and coagulation/flocculation/ sedimentation followed by diatomaceous earth filtration. A TOC reduction of 70 15% was achieved in three separate studies, although at a cost of 1 g/L or more of powered activated carbon. Revised quality criteria for recycled shower water have been developed with guidance from the National Research Council. Parameters which can practically be measured in the field are primarily associated with microbiological safety.

  8. 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.

  9. 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.

  10. 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.

  11. On Micro VAX farms and shower libraries: Monte Carlo techniques developed for the D0 detector

    SciTech Connect

    Raja, R.

    1988-01-01

    In order to predict correctly the effects of cracks and dead material in a nearly hermetic calorimeter, hadronic and electromagnetic showers need to be simulated accurately on a particle by particle basis. Tracking all the particles of all showers in the calorimeter leads to very large CPU times (typically 5 hours on a VAX780) for events at ..sqrt..(s) = 2TeV. Parametrizing the energy deposition of electromagnetic particles in showers with energy below 200 MeV results in event times of the order of 1 hour on a VAX780. This is still unacceptably large. The D0 collaboration then employed a farm of 16 MicroVax II's to get acceptable throughputs. The calorimeter hit patterns of each individual track was output, to be summed up by a later job. These individual hit patterns were entered into a random access shower library file, which was then used for subsequent Monte Carlo simulations. This shower library technique results in further speed-ups of a factor of 60 without degrading the quality of simulation significantly.

  12. 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.

  13. Status of the Whipple Observatory Cerenkov air shower imaging telescope array

    NASA Technical Reports Server (NTRS)

    Akerlof, C. W.; Cawley, M. F.; Fegan, D. J.; Fennell, S.; Freeman, S.; Frishman, D.; Harris, K.; Hillas, A. M.; Jennings, D.; Lamb, R. C.

    1992-01-01

    Recently the power of the Cerenkov imaging technique in Very High Energy gamma-ray astronomy was demonstrated by the detection of the Crab nebula at high statistical significance. In order to further develop this technique to allow the detection of weaker or more distant sources a second 10 m class reflector was constructed about 120 m from the original instrument. The addition of the second reflector will allow both a reduction in the energy threshold and an improvement in the rejection of the hadronic background. The design and construction of the second reflector, Gamma Ray Astrophysics New Imaging TElescope (GRANITE) is described.

  14. Detection of the Crab Nebula By UV Imaging of TeV Gamma Ray Air Showers

    NASA Astrophysics Data System (ADS)

    Chantell, M.

    1994-12-01

    With successful detection of TeV gamma ray fluxes from the Crab Nebula and the AGN, MRK421, the Whipple Observatory Gamma Ray Collaboration has demonstrated the sensitivity of the Cherenkov imaging technique in ground-based gamma-ray astronomy. This technique uses an array of 109 blue-sensitive photomultipliers to image the Cherenkov radiation produced when TeV gamma and cosmic rays enter the earth's atmosphere. One major limitation of this technique is the requirement of absolutely dark skies during observations. The presence of the moon rules out the possibility of making observations because of the high sensitivity of the photomultipliers used in the camera. To address this limitation we have developed a camera which utilizes solar-blind photomultpliers with primary sensitivity from 220nm to 280nm allowing observations even in the presence of the full moon. After two years of UV observations of the Crab Nebula we have demonstrated the ability to discriminate gamma rays from the hadronic background with an energy threshold of approximately 1 TeV. The development of this camera makes it possible to increase the duty cycle of the 10 meter telescope allowing observations in bright time. Additionally the insensitivity to background star light allows this camera to observe sources in bright regions of the galactic plane, where high background light levels have limited the usefulness of the visible camera.

  15. New survey of meteor showers

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.

    2014-07-01

    In order to confirm the many showers listed in the IAU Working List of Meteor Showers in need of verification, a 60-camera three-station video surveillance of the night sky is being conducted in the San Francisco Bay Area in California (http://cams.seti.org), called the Cameras for Allsky Meteor Surveillance (CAMS) project [1]. Now, the first 2.5 years of observations were reduced and analyzed, comprised of 112,024 meteoroid trajectories from mostly +4 to -2 magnitude meteors. The trajectories were calculated with a mean precision of 0.24° in radiant direction and 2 % in speed. An interactive tool was developed to study the distribution of meteoroid radiant and speed after correction for Earth's motion around the Sun. A report was submitted for publication in Icarus [2]. Our team assigned 30,801 meteors to 320 showers (27.5 %). This included 72 established showers and 64 known but now confirmed showers. An additional 24 previously reported showers were tentatively detected, but need further study. This study adds 105 potential new showers and 23 newly identified components of established showers to the IAU Working List of Meteor Showers. Another 32 showers previously reported based all or in part on CAMS data were detected again. The Northern and Southern Taurids, especially, are found to be composed of a series of individual streams. In this presentation, I will summarize statistical aspects of these shower detections and their relation to parent body near-Earth objects to shed light on the role of mostly dormant comets in contributing dust to the inner solar system.

  16. Searching for slow-developing cosmic-ray showers: Looking for evidence of exotic primaries at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Mayotte, Eric William

    The central purpose of this research was to add the event propagation velocity to the list of shower parameters that the Florescence Detector of Pierre Auger Observatory is capable of measuring. This capability was then leveraged to differentiate exotic slow moving events from the rest of the cosmic ray flux. Clearly, by relativistic necessity, all known cosmic ray primaries can only cause a measurable extensive air shower at velocities indistinguishably close to the speed of light. Therefore any accurate observation of an event propagating slower than the speed of light would provide an unmistakable indicator of new physics. A particle must possess very specific characteristics in order to be capable of producing a slow shower. High mass Strangelets, macroscopic dark matter, and super-symmetric Q-Balls were identified as strong candidates. Theory supporting high mass Strangelets and macroscopic dark matter appeared too late for full inclusion in this work, however super-symmetric Q-Balls were thoroughly examined. CORSIKA simulations were used to show that the fluorescence detector of the Pierre Auger Observatory has sensitivity to Q-Balls with a mass MQ > 3.25 x 1027 GeV c--2 while the surface detector is sensitive at a mass MQ > 1.15 x 10 27GeV c--2. The Pierre Auger Observatory was shown to be capable of accurately measuring a wide range of velocities with two independent methods. These methods were applied to 7 years of data and one candidate slow event was identified. This candidate measurement proved to be due to a rare and interesting, but ultimately, non-exotic effect, which when accounted for resulted in the event being measured normally. As a result of this, no exotic candidate events were found in the search. Recommendations are made for improving the result and promising alternative search methods are presented.

  17. Particles of primary cosmic radiation generating extensive air showers of energy above 1020 eV in the atmosphere

    NASA Astrophysics Data System (ADS)

    Dedenko, L. G.; Glushkov, A. V.; Knurenko, S. P.; Makarov, I. T.; Pravdin, M. I.; Podgrudkov, D. A.; Sleptzov, I. E.; Roganova, T. M.; Fedorova, G. F.; Fedunin, E. Yu.

    2010-12-01

    In order to construct the energy spectrum on the basis of data from the Yakutsk array, a method similar to that employed at the AGASA array is applied in addition to the standard approach based on experimental procedures. Moreover, a new, original, method underlying the calculation of the spectrum in the region of energies above 1020 eV is used to estimate energies. In order to compare data obtained at different arrays, it is proposed to harness the universal spectrum based on HiRes data. Within the QGSJET2 model, it is shown that a shower of energy 2 × 1020 eV was observed at the Yakutsk array. In the same energy region (above 2 × 1020 eV), the AGASA array recorded four showers, while the Fly's Eye array and Pierre Auger Observatory (PAO) recorded one shower each. These data do not confirm the conclusion that the flux of primary-cosmic-ray particles decreases because of the Greisen-Zatsepin-Kuzmin effect.

  18. EAS development curve at energy of 10(16) - 10(18) eV measured by optical Cerenkov light

    NASA Technical Reports Server (NTRS)

    Hara, T.; Daigo, M.; Honda, M.; Kamata, K.; Kifune, T.; Mizumoto, Y.; Nagano, M.; Ohno, Y.; Tanahasni, G.

    1985-01-01

    The data of optical Cerenkov light from extensive air shower observed at the core distance more than 1 Km at Akeno are reexamined. Applying the new simulated results, the shower development curves for the individual events were constructed. For the showers of 10 to 17th power eV the average depth at the shower maximum is determined to be 660 + or - 40 gcm/2. The shower curve of average development is found to be well described by a Gaisser-Hillas shower development function with above shower maximum depth.

  19. Electromagnetic and muonic structure of showers initiated by gamma-rays and by hadrons

    NASA Technical Reports Server (NTRS)

    Hillas, A. M.

    1985-01-01

    If photon cascades develop by the usual mechanisms, there should indeed be notable differences between the structure of showers due to photon and hadron primaries, as regards muon densities and lateral distributions of some detector signals. The muon content of showers from Cygnus X-3, observed at Kiel, cannot be understood in this way. One remedy is to postulate arbitrarily a strong hadronic interaction of photons in the TeV region. This would utterly change the nature of electromagnetic cascades, but surprisingly does not at first sight seem to be in conflict with air shower observations.

  20. Xmaxμ vs. Nμ from extensive air showers as estimator for the mass of primary UHECR's. Application for the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Arsene, Nicusor; Sima, Octavian

    2015-02-01

    We study the possibility of primary mass estimation for Ultra High Energy Cosmic Rays (UHECR's) using the Xmaxμ (the height where the number of muons produced on the core of Extensive Air Showers (EAS) is maximum) and the number Nμ of muons detected on ground. We use the 2D distribution - Xmaxμ against Nμ in order to find its sensitivity to the mass of the primary particle. For that, we construct a 2D Probability Function Prob(p,Fe | Xmaxμ, Nμ) which estimates the probability that a certain point from the plane (Xmaxμ, Nμ) 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 1019eV 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 Xmaxμ distributions.

  1. Precise determination of muon and electromagnetic shower contents from a shower universality property

    SciTech Connect

    Yushkov, A.; Ambrosio, M.; Aramo, C.; D'Urso, D.; Valore, L.; Guarino, F.

    2010-06-15

    We consider two new aspects of extensive air shower development universality allowing to make an accurate estimation of muon and electromagnetic (EM) shower contents in two independent ways. In the first case, to get the muon (or EM) signal in water Cherenkov tanks or in scintillator detectors, it is enough to know the vertical depth of the shower maximum X{sub max}{sup v} and the total signal in the ground detector. In the second case, the EM signal can be calculated from the primary particle energy and the zenith angle. In both cases, the parametrizations of muon and EM signals are almost independent on the primary particle nature, energy and zenith angle. Implications of the considered properties for mass composition and hadronic interaction studies are briefly discussed. The present study is performed on 28 000 proton, oxygen, and iron showers, generated with CORSIKA 6.735 for the E{sup -1} spectrum in the energy range lg (E/eV)=18.5-20 and uniformly distributed in cos{sup 2{theta}} in the zenith angle interval {theta}=0 deg. - 65 deg. for QGSJET II/Fluka interaction models.

  2. Investigation of the S(500) distribution for large air showers detected with the KASCADE-Grande array

    NASA Astrophysics Data System (ADS)

    Toma, G.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Trinchero, G.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; KASCADE-Grande Collaboration

    2009-12-01

    Previous EAS investigations have shown that the charged particle density becomes independent of the primary mass at certain distances from the shower core and can be used as an estimator for the primary energy. In the context of the KASCADE-Grande experiment, the particular distance to shower core at which t his effect takes place is around 500 m, hence the study at this particular distance and the notation S(500) for the charged particle density. It has been shown that S(500) maps the primary energy. We present results of further investigations in this direction. An attenuation correction function can be derived from the S(500) attenuation with the EAS angle of incidence, allowing us to build an all event S(500) spectrum. In view of a future conversion of the recorded S(500) spectrum to the primary energy, based on simulations a calibration of the observed S(500) values with the primary energies has been worked out (in the energy range accessible to the KASCADE-Grande array, 10-10 eV).

  3. Developing air quality forecasts

    NASA Astrophysics Data System (ADS)

    Lee, Pius; Saylor, Rick; Meagher, James

    2012-05-01

    Third International Workshop on Air Quality Forecasting Research; Potomac, Maryland, 29 November to 1 December 2011 Elevated concentrations of both near-surface ozone (O3) and fine particulate matter smaller than 2.5 micrometers in diameter have been implicated in increased mortality and other human health impacts. In light of these known influences on human health, many governments around the world have instituted air quality forecasting systems to provide their citizens with advance warning of impending poor air quality so that they can take actions to limit exposure. In an effort to improve the performance of air quality forecasting systems and provide a forum for the exchange of the latest research in air quality modeling, the International Workshop on Air Quality Forecasting Research (IWAQFR) was established in 2009 and is cosponsored by the U.S. National Oceanic and Atmospheric Administration (NOAA), Environment Canada (EC), and the World Meteorological Organization (WMO). The steering committee for IWAQFR's establishment was composed of Véronique Bouchet, Mike Howe, and Craig Stoud (EC); Greg Carmichael (University of Iowa); Paula Davidson and Jim Meagher (NOAA); and Liisa Jalkanen (WMO). The most recent workshop took place in Maryland.

  4. 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.

  5. 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.

  6. Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun.

    PubMed

    Amenomori, M; Ayabe, S; Cui, S W; Danzengluobu; Ding, L K; Ding, X H; Feng, C F; 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, J Y; Lu, H; Lu, S L; Meng, X R; Mizutani, K; Mori, S; Mu, J; Munakata, K; Nanjo, H; Nishizawa, M; Ohnishi, M; Ohta, I; Onuma, H; Ouchi, T; Ozawa, S; Ren, J R; Saito, T; Sakata, M; Sasaki, T; Shibata, M; Shiomi, A; Shirai, T; Sugimoto, H; Takita, M; Tan, Y H; Tateyama, N; Torii, S; Tsuchiya, H; Udo, S; Utsugi, T; Wang, B S; 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; Zhaxisangzhu; Zhou, X X

    2004-08-01

    We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made. PMID:15323615

  7. 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.

  8. Simulation of gamma-initiated showers

    NASA Technical Reports Server (NTRS)

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

    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.

  9. 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.

  10. Lithium-Air Cell Development

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.; Dobley, Arthur; Seymour, Frasier W.

    2014-01-01

    Lithium-air (Li-air) primary batteries have a theoretical specific capacity of 11,400 Wh/kg, the highest of any common metal-air system. NASA is developing Li-air technology for a Mobile Oxygen Concentrator for Spacecraft Emergencies, an application which requires an extremely lightweight primary battery that can discharge over 24 hours continuously. Several vendors were funded through the NASA SBIR program to develop Li-air technology to fulfill the requirements of this application. New catalysts and carbon cathode structures were developed to enhance the oxygen reduction reaction and increase surface area to improve cell performance. Techniques to stabilize the lithium metal anode surface were explored. Experimental results for prototype laboratory cells are given. Projections are made for the performance of hypothetical cells constructed from the materials that were developed.

  11. 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.

  12. Fast Shower Simulation in the ATLAS Calorimeter

    SciTech Connect

    Barberio, E.; Boudreau, J.; Butler, B.; Cheung, S.L.; Dell'Acqua, A.; Di Simone, A.; Ehrenfeld, W.; Gallas, M.V.; Glazov, A.; Marshall, Z.; Mueller, J.; Placakyte, R.; Rimoldi, A.; Savard, P.; Tsulaia, V.; Waugh, A.; Young, C.C.; /SLAC

    2011-11-08

    The time to simulate pp collisions in the ATLAS detector is largely dominated by the showering of electromagnetic particles in the heavy parts of the detector, especially the electromagnetic barrel and endcap calorimeters. Two procedures have been developed to accelerate the processing time of electromagnetic particles in these regions: (1) a fast shower parameterisation and (2) a frozen shower library. Both work by generating the response of the calorimeter to electrons and positrons with Geant 4, and then reintroduce the response into the simulation at runtime. In the fast shower parameterisation technique, a parameterization is tuned to single electrons and used later by simulation. In the frozen shower technique, actual showers from low-energy particles are used in the simulation. Full Geant 4 simulation is used to develop showers down to {approx} 1 GeV, at which point the shower is terminated by substituting a frozen shower. Judicious use of both techniques over the entire electromagnetic portion of the ATLAS calorimeter produces an important improvement of CPU time. We discuss the algorithms and their performance in this paper.

  13. The development of substitute inks and controls for reducing workplace concentrations of organic solvent vapors in a vinyl shower curtain printing plant.

    PubMed

    Piltingsrud, Harley V; Zimmer, Anthony T; Rourke, Aaron B

    2003-08-01

    During the summer of 1994, football players at a practice field reported noxious odors in the area. Ohio Environmental Protection Agency (OEPA) investigations of industries surrounding the field included a printing facility producing vinyl shower curtains with screen-printed designs. Though not the source of the odor, they were discharging volatile organic compounds directly to the environs in violation of OEPA regulations. To achieve compliance they installed a catalytic oxidizer for treating discharged air. Due to high equipment costs, the capacity of the installed catalytic oxidizer resulted in a substantial reduction in discharged air flow rates and increased solvent vapor concentrations within the workplace. Vapor levels caused worker discomfort, prompting a request for assistance from the Ohio Bureau of Workers Compensation. The vapor concentrations were found to exceed NIOSH, OSHA, and ACGIH acceptable exposure levels. The workers were then required to wear organic vapor removing respirators full-time while printing as a temporary protective measure. The company requested NIOSH assistance in finding methods to reduce solvent vapor concentrations. NIOSH studies included the identification of the sources and relative magnitude of solvent emissions from the printing process, the design of controls for the emissions, and the development of substitute inks using non-photochemically reactive solvents. The new ink system and controls allowed OEPA removal of the requirement for the treatment of discharged air and substantial increases in dilution ventilation. Increased ventilation would permit reduction in worker exposures to less than 1/3 mixture TLV levels and removal of requirements for respirator usage. This solution was the result of a comprehensive review of all facets of the problem, including OEPA regulations. It also required cooperative work between the company and federal, state, and local governmental agencies. PMID:12851010

  14. Reweighting parton showers

    NASA Astrophysics Data System (ADS)

    Bellm, Johannes; Plätzer, Simon; Richardson, Peter; Siódmok, Andrzej; Webster, Stephen

    2016-08-01

    We report on the possibility of reweighting parton-shower Monte Carlo predictions for scale variations in the parton-shower algorithm. The method is based on a generalization of the Sudakov veto algorithm. We demonstrate the feasibility of this approach using example physical distributions. Implementations are available for both of the parton-shower modules in the Herwig 7 event generator.

  15. 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.

  16. AEROSOLS CONTAINING 'LEGIONELLA PNEUMOPHILA' GENERATED BY SHOWER HEADS AND HOT-WATER FAUCETS

    EPA Science Inventory

    Shower heads and hot-water faucets containing Legionella pneumophila were evaluated for aerosolization of the organism with a multistage cascade impaction air sampler. Air was collected above two shower doors and from the same rooms approximately 3 ft (91 cm) from the shower door...

  17. Video meteor light curve analysis of Orionids and Geminids and developing a method for obtaining the absolute light curves of shower meteors from the single station data

    NASA Astrophysics Data System (ADS)

    Grašić, L.; Milanović, N.; Pavlović, D.

    2016-01-01

    We developed a method for obtaining the absolute light curves of the shower meteors from single station video data. We found that even though the height of a meteor atmospheric trajectory obtained by using this method may have a large error, the absolute light curve shape is preserved. We used our method to calculate the F parameters of the Orionid and Geminid light curves. The light curves were obtained from the single station video data by the instrument with a limiting sensitivity of 3.5m. We found that for our sample of the light curves the zenith distance of meteor radiant does not affect the F parameter for either of the two showers. The value of F parameter of the Orionids obtained in this paper matches the values obtained by other authors, whilst for the Geminids it is significantly different.

  18. Shower development of particles with momenta from 15 GeV to 150 GeV in the CALICE scintillator-tungsten hadronic calorimeter

    NASA Astrophysics Data System (ADS)

    Chefdeville, M.; Karyotakis, Y.; Repond, J.; Schlereth, J.; Xia, L.; Eigen, G.; Marshall, J. S.; Thomson, M. A.; Ward, D. R.; Alipour Tehrani, N.; Apostolakis, J.; Dannheim, D.; Elsener, K.; Folger, G.; Grefe, C.; Ivantchenko, V.; Killenberg, M.; Klempt, W.; van der Kraaij, E.; Linssen, L.; Lucaci-Timoce, A.-I.; Münnich, A.; Poss, S.; Ribon, A.; Roloff, P.; Sailer, A.; Schlatter, D.; Sicking, E.; Strube, J.; Uzhinskiy, V.; Chang, S.; Khan, A.; Kim, D. H.; Kong, D. J.; Oh, Y. D.; Blazey, G. C.; Dyshkant, A.; Francis, K.; Zutshi, V.; Giraud, J.; Grondin, D.; Hostachy, J.-Y.; Brianne, E.; Cornett, U.; David, D.; Falley, G.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Irles, A.; Karstensen, S.; Krivan, F.; Krüger, K.; Kvasnicka, J.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Provenza, A.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Tran, H. L.; Vargas-Trevino, A.; Garutti, E.; Laurien, S.; Matysek, M.; Ramilli, M.; Schröder, S.; Briggl, K.; Eckert, P.; Harion, T.; Munwes, Y.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Bilki, B.; Onel, Y.; Kawagoe, K.; Hirai, H.; Sudo, Y.; Suehara, T.; Sumida, H.; Takada, S.; Tomita, T.; Yoshioka, T.; Wing, M.; Calvo Alamillo, E.; Fouz, M.-C.; Marin, J.; Puerta-Pelayo, J.; Verdugo, A.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Markin, O.; Mizuk, R.; Novikov, E.; Rusinov, V.; Tarkovsky, E.; Kirikova, N.; Kozlov, V.; Smirnov, P.; Soloviev, Y.; Besson, D.; Buzhan, P.; Popova, E.; Gabriel, M.; Kiesling, C.; van der Kolk, N.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M. S.; Bonis, J.; Cornebise, P.; Richard, F.; Pöschl, R.; Rouëné, J.; Thiebault, A.; Anduze, M.; Balagura, V.; Boudry, V.; Brient, J.-C.; Cizel, J.-B.; Cornat, R.; Frotin, M.; Gastaldi, F.; Haddad, Y.; Magniette, F.; Nanni, J.; Pavy, S.; Rubio-Roy, M.; Shpak, K.; Tran, T. H.; Videau, H.; Yu, D.; Callier, S.; Conforti di Lorenzo, S.; Dulucq, F.; Fleury, J.; Martin-Chassard, G.; de la Taille, Ch.; Raux, L.; Seguin-Moreau, N.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kovalcuk, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Ieki, S.; Kamiya, Y.; Ootani, W.; Shibata, N.; Chen, S.; Jeans, D.; Komamiya, S.; Kozakai, C.; Nakanishi, H.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

    2015-12-01

    We present a study of showers initiated by electrons, pions, kaons, and protons with momenta from 15 GeV to 150 GeV in the highly granular CALICE scintillator-tungsten analogue hadronic calorimeter. The data were recorded at the CERN Super Proton Synchrotron in 2011. The analysis includes measurements of the calorimeter response to each particle type as well as measurements of the energy resolution and studies of the longitudinal and radial shower development for selected particles. The results are compared to Geant4 simulations (version 9.6.p02). In the study of the energy resolution we include previously published data with beam momenta from 1 GeV to 10 GeV recorded at the CERN Proton Synchrotron in 2010.

  19. 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.

  20. Analysis of inclined showers measured with LOPES

    NASA Astrophysics Data System (ADS)

    Lopes Collaboration; Saftoiu, A.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Auffenberg, J.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Over, S.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; LOPES Collaboration

    2009-06-01

    In the present study, we analyze the radio signal from inclined air showers recorded by LOPES-30 in coincidence with KASCADE-Grande. LOPES-30 consists of 30 East-West oriented digital antennas, which are amplitude calibrated by an external source. Radio emission from air showers is considered a geomagnetic effect. Inclined events provide a larger range of values for geomagnetic angle (angle between shower axis and geomagnetic field direction) than vertical showers and thus more information on the emission processes can be gathered. In order to have the geometry of the air shower we use the reconstruction provided by the KASCADE-Grande particle detectors array. Analyzing events observed by both LOPES and the extended part of the KASCADE array, Grande, gives the possibility to test in particular the capability and efficiency of radio detection of more distant events. The results are compared with a previous analysis of inclined events recorded by the initial 10 antenna set-up, LOPES-10, in coincidence with the Grande array.

  1. 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.

  2. AIR TOXICS DEVELOPMENT AT EPA

    EPA Science Inventory

    The paper gives an overview of research activities in EPA's Air and Energy Engineering Research Laboratory, including the identification, assessment, and control of sources of volatile organic compounds (VOCs), hazardous air pollutants (NAPs), and chlorofluorocarbons (CFCs). VOCs...

  3. Shower counter resolution scaling

    SciTech Connect

    Kirk, T.B.W.

    1991-10-14

    The EM shower counter for the SDC detector has a resolution expression containing two stochastic terms plus a constant term. Recent measurements clarifying the sources of these terms are presented here. 3 refs., 4 figs.

  4. Portable Water-Saving Shower For Emergencies

    NASA Technical Reports Server (NTRS)

    Grenier, Francis E.

    1991-01-01

    Stowable compact unit sprays from many directions. Proposed portable emergency fogging shower rinses harmful chemicals from person. Includes double-walled transparent, approximately cylindrical curtain containing sets of interior nozzles on regularly spaced loops. Sealed at top and bottom. Victim of contamination enters through longitudinal zippered opening. Pressurized mixture of air and water flows through selected nozzles, creating foglike spray scrubbing contaminants from skin and clothing. Intended for use on Space Station, also used in laboratories and factories on Earth, or for routine shower bathing in areas with limited water supplies.

  5. The Crisis in Air Pollution Manpower Development

    ERIC Educational Resources Information Center

    Moeller, Dade W.

    1974-01-01

    Three studies conducted by the National Air Pollution Manpower Development Advisory Committee concluded there is a crisis in air pollution manpower development within the United States today. The studies investigated the existing federal manpower program, air pollution educational requirements and the quality of graduate level university programs.…

  6. 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.

  7. Particle distributions in approximately 10(13) - 10(16) eV air shower cores at mountain altitude and comparison with Monte Carlo simulations

    NASA Technical Reports Server (NTRS)

    Ash, A. G.

    1985-01-01

    Photographs of 521 shower cores in an array of current-limited spark (discharge) chambers at Sacramento Peak (2900m above sea level, 730 g /sq cm.), New Mexico, U.S.A., have been analyzed and the results compared with similar data from Leeds (80m above sea level, 1020 g sq cm.). It was found that the central density differential spectrum is consistent with a power law index of -2 up to approx. 1500/sq m where it steepens, and that shower cores become flatter on average with increasing size. Scaling model predictions for proton primaries with a approx E sup -2.71 energy spectrum account well for the altitude dependence of the data at lower densities. However, deviations at higher densities indicate a change in hadron interaction characteristics between approx few x 10 to the 14th power and 10 to the 15th power eV primary energy causing particles close to the shower axis to be spread further out.

  8. Continuous monitoring of particle emissions during showering.

    PubMed

    Cowen, Kenneth A; Ollison, Will M

    2006-12-01

    Particle formation from showering may be attributed to dissolved mineral aerosols remaining after evaporation of micron-sized satellite droplets produced by the showerhead or from splashing of larger shower water droplets on surfaces. Duplicate continuous particle monitors measured particle size distributions in a ventilated residential bathroom under various showering conditions, using a full-size mannequin in the shower to simulate splashing effects during showering. Particle mass concentrations were estimated from measured shower particle number densities and used to develop emission factors for inhalable particles. Emission source strengths of 2.7-41.3 microg/ m3/min were estimated under the various test conditions using residential tap water in Columbus, OH. Calculated fine particulate matter (PM2.5) concentrations in the bathroom reached several hundred micrograms per cubic meter; calculated coarse particulate matter (PM10) levels approached 1000 microg/m3. Rates of particle formation tended to be highest for coarse shower spray settings with direct impact on the mannequin. No consistent effects of water temperature, water pressure, or spray setting on overall emission rates were apparent, although water temperature and spray setting did have an effect when varied within a single shower sampling run. Salt solutions were injected into the source water during some tests to assess the effects of total dissolved solids on particle emission rates. Injection of salts was shown to increase the PM2.5 particle formation rate by approximately one third, on average, for a doubling in tap water-dissolved solids content; PM10 source strengths approximately doubled under these conditions, because very few particles >10 microm were formed. PMID:17195485

  9. Development of the Air Transport Industry

    NASA Technical Reports Server (NTRS)

    Taneja, N.

    1972-01-01

    The major developments are outlined in the U.S. scheduled air transport industry both domestic and international, together with a brief history of the European air transport system. The role and formulation of the U.S. Civil Aeronautics Board, International Civil Aviation Organization, and International Air Transport Association are also covered.

  10. Air Force Training for Instructional Systems Development.

    ERIC Educational Resources Information Center

    Calkins, Ronald R.

    Detailed information is provided about the Air Force Instructional System Development (ISD) Model to supplement the 1979 AECT presentation made in New Orleans. Information of interest to instructional systems designers includes (1) a short overview of the Air Force ISD model, (2) an extended example which demonstrates the Air Training Command…

  11. 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.

  12. Showering on Skylab

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A close up view of astronaut Jack R. Lousma, Skylab 3 pilot taking a hot bath in the crew quarters of the Orbital Workshop (OWS) of the Skylab space station cluster in Earth Orbit. This picture was taken with a hand-held 35mm Nikon camera. Astronaut Lousma, Alan Bean and Owen K. Garriott remained within the Skylab space station in orbit for 59 days conducting numerous medical, scientific and technological expierments. In deploying the shower facility the shower curtain is pulled up from the floor and attached to the ceiling. The water comes through a push-button shower head attached to a flexible hose. Water is drawn off by a vacuum system.

  13. 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.

  14. Development of a New Fast Shower Maximum Detector Based on Microchannel Plates Photomultipliers (MCP-PMT) as an Active Element

    SciTech Connect

    Ronzhin, A.; Los, S.; Ramberg, E.; Spiropulu, M.; Apresyan, A.; Xie, S.; Kim, H.; Zatserklyaniy, A.

    2014-09-21

    One possibility to make a fast and radiation resistant shower maximum (SM) detector is to use a secondary emitter as an active element. We present below test beam results, obtained with different types of photodetectors based on microchannel plates (MCPs) as the secondary emitter. We performed the measurements at the Fermilab Test Beam Facility with 120GeV proton beam and 12GeV and 32GeV secondary beams. The goal of the measurement with 120GeV protons was to determine time resolution for minimum ionizing particles (MIPs). The SM time resolution we obtained for this new type of detector is at the level of 20-30ps. We estimate that a significant contribution to the detector response originates from secondary emission of the MCP. This work can be considered as the first step in building a new type of calorimeter based on this principle.

  15. Development of a new fast shower maximum detector based on microchannel plates photomultipliers (MCP-PMT) as an active element

    NASA Astrophysics Data System (ADS)

    Ronzhin, A.; Los, S.; Ramberg, E.; Spiropulu, M.; Apresyan, A.; Xie, S.; Kim, H.; Zatserklyaniy, A.

    2014-09-01

    One possibility to make a fast and radiation resistant shower maximum (SM) detector is to use a secondary emitter as an active element. We present below test beam results, obtained with different types of photodetectors based on microchannel plates (MCPs) as the secondary emitter. We performed the measurements at the Fermilab Test Beam Facility with 120 GeV proton beam and 12 GeV and 32 GeV secondary beams. The goal of the measurement with 120 GeV protons was to determine time resolution for minimum ionizing particles (MIPs). The SM time resolution we obtained for this new type of detector is at the level of 20-30 ps. We estimate that a significant contribution to the detector response originates from secondary emission of the MCP. This work can be considered as the first step in building a new type of calorimeter based on this principle.

  16. Computer Developments in Air Conditioning.

    ERIC Educational Resources Information Center

    Pancoast, Ferendino, Grafton and Skeels, Architects, Miami, FL.

    Proceedings of a conference on the present and future uses of computer techniques in the air conditioning field. The recommendation of this report is, for the most part, negative insofar as it applies to the use of computers for design by the small office. However, there should be an awareness of their usefulness in controlling the environmental…

  17. 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.

  18. Mass composition of 10{sup 17}- to 10{sup 18}-eV primary cosmic rays according to data on the lateral distribution of radio emission from extensive air showers

    SciTech Connect

    Kalmykov, N. N. Konstantinov, A. A.; Vedeneev, O. V.

    2012-12-15

    Experimental data obtained for the lateral distribution of radio emission from extensive air showers (EAS) at the array of Moscow State University (30-34 MHz) and the LOPES array (40-80 MHz) were comparedwith the results of calculations performed within amicroscopic approach based on aMonte Carlo simulation of EAS (CORSIKA code). The same experimental data were used to reconstruct the distribution of the depth of the EAS maximum at cosmic-ray energies in the range of 1017-1018 eV. The energy dependence of the depth of the EAS maximum was constructed for the case of data from the LOPES array, and the mass composition of cosmic rays was estimated for this case. From the resulting dependences, it follows that the mass composition shows a trend toward becoming lighter in the energy range being considered.

  19. Multiple shell shower fronts in EAS with ARGO-YBJ

    NASA Astrophysics Data System (ADS)

    Marsella, G.

    2015-08-01

    The ARGO-YBJ experiment is an Extensive Air Shower array that has been operated at the high altitude Yangbajing Cosmic Ray Laboratory (Tibet, P.R. China 4300 m a.s.l.) in its final configuration since December 2007 until February 2013. The detector consists of a dense layer of Resistive Plate Counters (RPCs) covering an area of about 11000 m2. It has been designed to measure the temporal and spatial structure of Extensive Air Showers (EAS) with high space-time resolution. The detector gives a quite highly detailed picture of shower footprints at ground. It is perfectly suitable to understand the EAS morphology. These detector characteristics have been used for seeking particles of large rest mass produced in cosmic rays by measuring the Multiple Shell Shower Fronts relative delays. The technique and preliminary results will be illustrated in the present work.

  20. Shower disc sampling and the angular resolution of gamma-ray shower detectors

    NASA Technical Reports Server (NTRS)

    Lambert, A.; Lloyd-Evans, J.

    1985-01-01

    As part of the design study for the new UHE gamma ray detector being constsructed at Haverah Park, a series of experiments using scintillators operated side-by-side in 10 to the 15th power eV air showers are undertaken. Investigation of the rms sampling fluctuations in the shower disc arrival time yields an upper limit to the intrinsic sampling uncertainty, sigma sub rms = (1.1 + or - 0.1)ns, implying an angular resolution capability 1 deg for an inter-detector spacing of approximately 25 m.

  1. The Orbital Workshop Shower Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This photograph shows technicians performing a checkout of the Metabolic Analyzer (center background) and the Ergometer (foreground) in the Orbital Workshop (OWS). The shower compartment is at right. The Ergometer (Skylab Experiment M171) evaluated man's metabolic effectiveness and cost of work in space environment. Located in the experiment and work area of the OWS, the shower compartment was a cylindrical cloth enclosure that was folded flat when not in use. The bottom ring of the shower was fastened to the floor and contained foot restraints. The upper ring contained the shower head and hose. To use the shower, the astronaut filled a pressurized portable bottle with heated water and attached the bottle to the ceiling. A flexible hose cornected the water bottle to a handheld shower head. The astronaut pulled the cylindrical shower wall up into position and bathed, using liquid soap. Both soap and water were carefully rationed, having been premeasured for economical use.

  2. The Orbital Workshop Shower Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    In this photograph, the Orbital Workshop shower compartment was unfolded by technicians for inspection. The shower compartment was a cylindrical cloth enclosure that was folded flat when not in use. The bottom ring of the shower was fastened to the floor and contained foot restraints. The upper ring contained the shower head and hose. To use the shower, the astronaut filled a pressurized portable bottle with heated water and attached the bottle to the ceiling. A flexible hose cornected the water bottle to a handheld shower head. The astronaut pulled the cylindrical shower wall up into position and bathed, using liquid soap. Both soap and water were carefully rationed, having been premeasured for economical use.

  3. The Upsilon Pegasid Meteor Shower

    NASA Astrophysics Data System (ADS)

    Povenmire, H.

    1995-09-01

    ]. These events showed a confirmed shower at least 20 days in length. The radiant appears to be approximately 3 degrees in diameter. Computer modeling using the D-criterion developed by Southworth and Hawkins [8] indicate that it could be much larger [3]. It is likely an old shower that is still intact, not disrupted by planetary perturbations due to its high inclination. These meteors cross the Earth's orbit while approaching the Sun. They arrive at perihelion about September 16.0 at a perihelion distance of 0.19 AU, half that of Mercury's orbit. The Earth travels through this nearly vertically inclined stream in almost the shortest possible interval. A shower duration as noted indicates a diameter of approximately 0.6 AU. References: [1] Povenmire H. (1980) Fireballs, Meteors and Meteorites, J.S.B. Enterprises Indian Harbour Beach, Florida, 215 pp. [2] Ceplecha Z. (1982) S.E.A.N. Bulletin, 7, 13-14. [3] Kronk G. (1988) Meteor Showers; A Descriptive Catalog, Enslow, Hillside, New Jersey, 281 pp. [4] Olivier C. P. (1937) Astrophys. J., 46, 41-56. [5] Simakina E. G. (1967) Solar System Res., 1, 96-121. [6] Babadzhanov P.B. (1963) Smithson. Contrib. Astrophys., 7, 287-291. [7] McCroskey R. and Posen A. (1961) Smithson. Contrib. Astrophys., 4, 15-84. [8] Southworth R. B. and Hawkins G. S. (1963) Smithson. Contrib. Astrophys., 7, 261-285.

  4. Air Tightness of US Homes: Model Development

    SciTech Connect

    Sherman, Max H.

    2006-05-01

    Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air leakage data from many sources and now has a database of more than 100,000 raw measurements. This paper uses that database to develop a model for estimating air leakage as a function of climate, building age, floor area, building height, floor type, energy-efficiency and low-income designations. The model developed can be used to estimate the leakage distribution of populations of houses.

  5. 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.

  6. 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.

  7. Development of Air Speed Nozzles

    NASA Technical Reports Server (NTRS)

    Zahm, A F

    1920-01-01

    Report describes the development of a suitable speed nozzle for the first few thousand airplanes made by the United States during the recent war in Europe, and to furnish a basis for more mature instruments in the future. Requirements for the project were to provide a suitable pressure collector for aircraft speed meters and to develop a speed nozzle which would be waterproof, powerful, unaffected by slight pitch and yaw, rugged and easy to manufacture, and uniform in structure and reading, so as not to require individual calibration.

  8. Air Force cryocooler development for spacecraft

    NASA Technical Reports Server (NTRS)

    Haskin, William L.

    1987-01-01

    An overview is given of Air Force sponsored cryocooler development for long duration spacecraft missions. Alternate approaches are being pursued to insure eventual success. The types of closed cycle cryocoolers that are now in advanced development include Vuilleumier, turbo-Brayton, and rotary-reciprocating refrigerators. Linear Stirling coolers with magnetic bearings have also been jointly sponsored by NASA and the Air Force. Technology is also being explored for future coolers using magnetic materials at low temperatures and for refrigerators with sorption compresssors. All of these cryocoolers are presently configured primarily for use with infrared sensor systems, but the designs could be adapted for use with cryogenic fluid storage systems or other applications.

  9. 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 ...

  10. Developing Interoperable Air Quality Community Portals

    NASA Astrophysics Data System (ADS)

    Falke, S. R.; Husar, R. B.; Yang, C. P.; Robinson, E. M.; Fialkowski, W. E.

    2009-04-01

    Web portals are intended to provide consolidated discovery, filtering and aggregation of content from multiple, distributed web sources targeted at particular user communities. This paper presents a standards-based information architectural approach to developing portals aimed at air quality community collaboration in data access and analysis. An important characteristic of the approach is to advance beyond the present stand-alone design of most portals to achieve interoperability with other portals and information sources. We show how using metadata standards, web services, RSS feeds and other Web 2.0 technologies, such as Yahoo! Pipes and del.icio.us, helps increase interoperability among portals. The approach is illustrated within the context of the GEOSS Architecture Implementation Pilot where an air quality community portal is being developed to provide a user interface between the portals and clearinghouse of the GEOSS Common Infrastructure and the air quality community catalog of metadata and data services.

  11. Air Force Research Laboratory Cryocooler Technology Development

    NASA Astrophysics Data System (ADS)

    Davis, Thomas M.; Smith, D. Adam; Easton, Ryan M.

    2004-06-01

    This paper presents an overview of the cryogenic refrigerator and cryogenic integration programs in development and characterization under the Cryogenic Cooling Technology Group, Space Vehicles Directorate of the Air Force Research Laboratory (AFRL). The vision statement for the group is to support the space community as the center of excellence for developing and transitioning space cryogenic thermal management technologies. This paper will describe the range of Stirling, pulse tube; reverse Brayton, and Joule-Thomson cycle cryocoolers currently under development to meet current and future Air Force and Department of Defense requirements. Cooling requirements at 10K, 35K, 60K, 95K, and multistage cooling requirements at 35/85K are addressed. In order to meet these various requirements, the Air Force Research Laboratory, Space Vehicles Directorate is pursuing various strategic cryocooler and cryogenic integration options. The Air Force Research Laboratory, working with industry partners, is also developing several advanced cryogenic integration technologies that will result in the reduction in current cryogenic system integration penalties and design time. These technologies include the continued development of gimbaled transport systems, 35K and 10K thermal storage units, heat pipes, cryogenic straps, and thermal switches.

  12. Exogenous and Endogenous Determinants of Blood Trihalomethane Levels after Showering

    PubMed Central

    Backer, Lorraine C.; Lan, Qing; Blount, Benjamin C.; Nuckols, J.R.; Branch, Robert; Lyu, Christopher W.; Kieszak, Stephanie M.; Brinkman, Marielle C.; Gordon, Sydney M.; Flanders, W. Dana; Romkes, Marjorie; Cantor, Kenneth P.

    2008-01-01

    Background We previously conducted a study to assess whether household exposures to tap water increased an individual’s internal dose of trihalomethanes (THMs). Increases in blood THM levels among subjects who showered or bathed were variable, with increased levels tending to cluster in two groups. Objectives Our goal was to assess the importance of personal characteristics, previous exposures, genetic polymorphisms, and environmental exposures in determining THM concentrations in blood after showering. Methods One hundred study participants completed a health symptom questionnaire, a 48-hr food and water consumption diary, and took a 10-min shower in a controlled setting. We examined THM levels in blood samples collected at baseline and 10 and 30 min after the shower. We assessed the significance of personal characteristics, previous exposures to THMs, and specific gene polymorphisms in predicting postshower blood THM concentrations. Results We did not observe the clustering of blood THM concentrations observed in our earlier study. We found that environmental THM concentrations were important predictors of blood THM concentrations immediately after showering. For example, the chloroform concentration in the shower stall air was the most important predictor of blood chloroform levels 10 min after the shower (p < 0.001). Personal characteristics, previous exposures to THMs, and specific polymorphisms in CYP2D6 and GSTT1 genes were significant predictors of both baseline and postshowering blood THM concentrations as well as of changes in THM concentrations associated with showering. Conclusion The inclusion of information about individual physiologic characteristics and environmental measurements would be valuable in future studies to assess human health effects from exposures to THMs in tap water. PMID:18197300

  13. Captain Development Training at US Air

    NASA Technical Reports Server (NTRS)

    Fickes, S.

    1984-01-01

    The flight training program practiced at US Air is reviewed. The background and development of the program are discussed. Specific program activities and curricula are considered. The issue of educating pilots to be aware of and admit significant flight stress and stress in their personal lives is addressed.

  14. 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.

  15. The influence of physicochemical properties on the internal dose of trihalomethanes in humans following a controlled showering exposure.

    PubMed

    Silva, Lalith K; Backer, Lorraine C; Ashley, David L; Gordon, Sydney M; Brinkman, Marielle C; Nuckols, John R; Wilkes, Charles R; Blount, Benjamin C

    2013-01-01

    Although disinfection of domestic water supply is crucial for protecting public health from waterborne diseases, this process forms potentially harmful by-products, such as trihalomethanes (THMs). We evaluated the influence of physicochemical properties of four THMs (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) on the internal dose after showering. One hundred volunteers showered for 10 min in a controlled setting with fixed water flow, air flow, and temperature. We measured THMs in shower water, shower air, bathroom air, and blood samples collected at various time intervals. The geometric mean (GM) for total THM concentration in shower water was 96.2 μg/l. The GM of total THM in air increased from 5.8 μg/m(3) pre shower to 351 μg/m(3) during showering. Similarly, the GM of total-blood THM concentration increased from 16.5 ng/l pre shower to 299 ng/l at 10 min post shower. THM levels were significantly correlated between different matrices (e.g. dibromochloromethane levels) in water and air (r=0.941); blood and water (r=0.845); and blood and air (r=0.831). The slopes of best-fit lines for THM levels in water vs air and blood vs air increased with increasing partition coefficient of water/air and blood/air. The slope of the correlation plot of THM levels in water vs air decreased in a linear (r=0.995) fashion with increasing Henry's law constant. The physicochemical properties (volatility, partition coefficients, and Henry's law constant) are useful parameters for predicting THM movement between matrices and understanding THM exposure during showering. PMID:22829048

  16. 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.

  17. Fluctuations of development maximum depth and nuclear composition of primary cosmic radiation

    NASA Technical Reports Server (NTRS)

    Dyakonov, M. N.; Knurenko, S. P.; Krasilnikov, D. D.; Sleptsov, I. Y.; Pavlov, V. N.; Ivanov, A. A.; Kolosov, V. A.; Struchkov, G. G.

    1985-01-01

    The extensive air showers (EAS) cascade curves from the Cerenkov light lateral distribution measurements are recovered and the maximum depth fluctuations of the shower development theta x sub m both on the Cerenkov and charged EAS components are defined. At E sub 0 approximates 10 to the 18th power eV the mean content of protons is greater than 85%, and p-air cross section theta sub 0 p-air 750mb.

  18. 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)

  19. Zinc air battery development for electric vehicles

    NASA Astrophysics Data System (ADS)

    Putt, R. A.; Merry, G. W.

    1991-07-01

    This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this 'soluble' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (greater than 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high resistance failure of the cell. The Phase 1 program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/sq cm. By the end of the Phase 1 program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase 2 program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

  20. Zinc air battery development for electric vehicles

    SciTech Connect

    Putt, R.A.; Merry, G.W. )

    1991-07-01

    This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this soluble'' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/cm{sup 2}. By the end of the Phase I program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase II program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

  1. Aerosols containing Legionella pneumophila generated by shower heads and hot-water faucets.

    PubMed Central

    Bollin, G E; Plouffe, J F; Para, M F; Hackman, B

    1985-01-01

    Shower heads and hot-water faucets containing Legionella pneumophila were evaluated for aerosolization of the organism with a multistage cascade impaction air sampler. Air was collected above two shower doors and from the same rooms approximately 3 ft (91 cm) from the shower doors while the hot water was running. Low numbers (3 to 5 CFU/15 ft3 [0.43 m3] of air) of L. pneumophila were recovered above both shower doors, but none was recovered from the air in either room outside the shower door. Approximately 90% (7 of 8 CFU) of the L. pneumophila recovered were trapped in aerosol particles between 1 and 5 micron in diameter. Air was collected 1 to 3 ft (30 to 91 cm) from 14 sinks while the hot water was running. Low numbers (1 to 5 CFU/15 ft3 of air) were recovered from 6 of 19 air samples obtained. Approximately 50% (6 of 13 CFU) of the organisms recovered were trapped in aerosol particles between 1 and 8 microns in diameter. Shower heads and hot-water taps containing L. pneumophila can aerosolize low numbers of the organism during routine use. The aerosol particle size is small enough to penetrate to the lower human respiratory system. Thus, these sites may be implicated as a means of transmission of L. pneumophila from potable water to the patient. PMID:4091548

  2. Air cushion craft development, first revision

    NASA Astrophysics Data System (ADS)

    Mantle, P. J.

    1980-01-01

    The development of air cushion craft from their inception to the present day is described. Both aerostatic craft known as air cushion vehicles and surface effect ships as well as aerodynamic craft such as wing-in-ground effect vehicles are covered. The various available theories, empirical laws, and experimental data were brought together and expressed in unified form. Emphasis is given to reducing the data and analysis to their simplest forms for easy understanding and isolation of fundamental parameters. Currently operational craft, those still in their construction jigs, or in some cases those still on the drawing board are assessed and compared to the basic theories to give a measure of the state-of-the-art. Such topics as performance, propulsion, ride quality, and high speed aerodynamic craft are included.

  3. 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.

  4. Development of Gigahertz Analog Memory for Front-End Electronics of Imaging Air Cherenkov Telescopes

    NASA Astrophysics Data System (ADS)

    Mizukami, T.; Higashi, Y.; Nakano, S.; Nakamori, T.; Kubo, H.; Tanimori, T.; Tanaka, M.

    The night sky light is one of the major components of background for imaging air Cherenkov telescopes. It disturbs images of air shower and makes both the gamma/hadron separation and the angular resolution worse. For example, The CANGAROO-III electronics consists of charge ADCs and multi-hit TDCs. In using charge ADCs, we have to delay the signal from PMTs until the trigger signal input to ADCs. After through this delay line chip, signals from PMTs are distorted, and we have to take the signal integration time longer than Cherenkov signal time constant and more night sky light is mixed to the real signal. In order to reduce this night sky light, we are planning to replace the charge ADCs to capacitor arrays called AMC (Analog Memory Cell). AMC consists of 512 capacitors and can record the waveform of the input signal for 512 ns at high sampling rate of 1 GHz. We already developed a test type of AMC chip and its dynamic range is more than 7 bits. We will report the current status of the development of AMC.

  5. Development and Evaluation of the Air Travel Stress Scale

    ERIC Educational Resources Information Center

    Bricker, Jonathan B.

    2005-01-01

    Despite anecdotal evidence suggesting that air travel is personally demanding, little research has examined air travel stress. To address these issues, the author developed and evaluated the 1st known measure of air travel stress-the Air Travel Stress Scale-in 3 studies. Exploratory and confirmatory factor analysis indicated 3 components: (a)…

  6. 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. PMID:21141853

  7. 1997 Leonid Shower From Space

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Nugent, David; Murthy, Jayant; Tedesco, Ed; DeVincenzi, Donal L. (Technical Monitor)

    2000-01-01

    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(exp -5)/sq km hr for masses greater than 0.3 gram. The limiting magnitude for limb observations of Leonid meteors was measured at M(sub v) = -1.5 magn The Leonid shower magnitude population index was 1.6 +/- 0.2 down to M(sub v) = -7 magn., with no sign of an upper mass cut-off.

  8. 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.

  9. 49 CFR 228.321 - Showering facilities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  10. Photomultiplier tube selection for the Wide Field of view Cherenkov/fluorescence Telescope Array of the Large High Altitude Air Shower Observatory

    NASA Astrophysics Data System (ADS)

    Ge, Maomao; Zhang, Li; Chen, Yingtao; Cao, Zhen; Zhang, Shoushan; Wang, Chong; Bi, Baiyang

    2016-05-01

    For the purpose of selecting the most suitable photomultiplier tubes (PMTs) for the Wide Field of view Cherenkov/fluorescence Telescope Array (WFCTA), we have performed extensive tests on seven models of 25.4 mm PMTs: Hamamatsu R1924A and R7899, Beijing Hamamatsu CR303, CR332A and CR364, and HZC Photonics XP3102 and XP3182. A dedicated test system has been developed to measure the PMT characteristics such as single photo-electron spectrum, gain, linearity, and spatial uniformity of anode output. The XP3182 and CR364 (R7899) tubes both meet the pivotal requirement due to their superior pulse linearity. The PMT test system, techniques used for these measurements, and their results are also reported.

  11. 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. PMID:15138448

  12. 46 CFR 154.1410 - Decontamination shower.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Decontamination shower. 154.1410 Section 154.1410... Equipment § 154.1410 Decontamination shower. When Table 4 references this section, a vessel carrying the listed cargo must have a decontamination shower and an eye wash that: (a) Are on the weatherdeck; and...

  13. 46 CFR 154.1410 - Decontamination shower.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Decontamination shower. 154.1410 Section 154.1410... Equipment § 154.1410 Decontamination shower. When Table 4 references this section, a vessel carrying the listed cargo must have a decontamination shower and an eye wash that: (a) Are on the weatherdeck; and...

  14. 46 CFR 154.1410 - Decontamination shower.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Decontamination shower. 154.1410 Section 154.1410... Equipment § 154.1410 Decontamination shower. When Table 4 references this section, a vessel carrying the listed cargo must have a decontamination shower and an eye wash that: (a) Are on the weatherdeck; and...

  15. 46 CFR 154.1410 - Decontamination shower.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Decontamination shower. 154.1410 Section 154.1410... Equipment § 154.1410 Decontamination shower. When Table 4 references this section, a vessel carrying the listed cargo must have a decontamination shower and an eye wash that: (a) Are on the weatherdeck; and...

  16. 46 CFR 154.1410 - Decontamination shower.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Decontamination shower. 154.1410 Section 154.1410... Equipment § 154.1410 Decontamination shower. When Table 4 references this section, a vessel carrying the listed cargo must have a decontamination shower and an eye wash that: (a) Are on the weatherdeck; and...

  17. Enabling Mobile Air Quality App Development with an AirNow API

    NASA Astrophysics Data System (ADS)

    Dye, T.; White, J. E.; Ludewig, S. A.; Dickerson, P.; Healy, A. N.; West, J. W.; Prince, L. A.

    2013-12-01

    The U.S. Environmental Protection Agency's (EPA) AirNow program works with over 130 participating state, local, and federal air quality agencies to obtain, quality control, and store real-time air quality observations and forecasts. From these data, the AirNow system generates thousands of maps and products each hour. Each day, information from AirNow is published online and in other media to assist the public in making health-based decisions related to air quality. However, an increasing number of people use mobile devices as their primary tool for obtaining information, and AirNow has responded to this trend by publishing an easy-to-use Web API that is useful for mobile app developers. This presentation will describe the various features of the AirNow application programming interface (API), including Representational State Transfer (REST)-type web services, file outputs, and RSS feeds. In addition, a web portal for the AirNow API will be shown, including documentation on use of the system, a query tool for configuring and running web services, and general information about the air quality data and forecasts available. Data published via the AirNow API includes corresponding Air Quality Index (AQI) levels for each pollutant. We will highlight examples of mobile apps that are using the AirNow API to provide location-based, real-time air quality information. Examples will include mobile apps developed for Minnesota ('Minnesota Air') and Washington, D.C. ('Clean Air Partners Air Quality'), and an app developed by EPA ('EPA AirNow').

  18. 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.

  19. Analysis of visual plotting accuracy and sporadic pollution and consequences for shower association.

    NASA Astrophysics Data System (ADS)

    Koschack, R.

    1991-12-01

    An analysis of the plotting accuracy and of the sporadic pollution for visual meteor observations is given. It is found that both factors limit the observability of minor showers to ZHR ≥ 3. Based on the results of the analysis, rules are developed for minor shower observations.

  20. 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.

  1. New directions: Air pollution challenges for developing megacities like Delhi

    NASA Astrophysics Data System (ADS)

    Kumar, Prashant; Khare, Mukesh; Harrison, Roy M.; Bloss, William J.; Lewis, Alastair C.; Coe, Hugh; Morawska, Lidia

    2015-12-01

    Most major cities around the world experience periods of elevated air pollution levels, which exceed international health-based air quality standards (Kumar et al., 2013). Although it is a global problem, some of the highest air pollution levels are found in rapidly expanding cities in India and China. The sources, emissions, transformations and broad effects of meteorology on air pollution are reasonably well accounted in air quality control strategies in many developed cities; however these key factors remain poorly constrained in the growing cities of countries with emerging economies. We focus here on Delhi, one of the largest global population centres, which faces particular air pollution challenges, now and in the future.

  2. Air Cherenkov methods in cosmic rays: Review and some history

    NASA Astrophysics Data System (ADS)

    Lidvansky, A. S.

    2006-08-01

    Radiation first discovered by Pavel Cherenkov is used for developing a variety of methods in cosmic-ray studies. Among them, air Cherenkov methods form a separate area with several lines of research. Numerous applications of air Cherenkov radiation in studies of extensive air showers, in γ-astronomy and neutrino physics are reviewed. A tribute is given to Alexander Chudakov whose pioneer ideas and experimental skill laid foundation for the present-day progress.

  3. HUMID AIR TURBINE CYCLE TECHNOLOGY DEVELOPMENT PROGRAM

    SciTech Connect

    Richard Tuthill

    2002-07-18

    The Humid Air Turbine (HAT) Cycle Technology Development Program focused on obtaining HAT cycle combustor technology that will be the foundation of future products. The work carried out under the auspices of the HAT Program built on the extensive low emissions stationary gas turbine work performed in the past by Pratt & Whitney (P&W). This Program is an integral part of technology base development within the Advanced Turbine Systems Program at the Department of Energy (DOE) and its experiments stretched over 5 years. The goal of the project was to fill in technological data gaps in the development of the HAT cycle and identify a combustor configuration that would efficiently burn high moisture, high-pressure gaseous fuels with low emissions. The major emphasis will be on the development of kinetic data, computer modeling, and evaluations of combustor configurations. The Program commenced during the 4th Quarter of 1996 and closed in the 4th Quarter of 2001. It teamed the National Energy Technology Laboratory (NETL) with P&W, the United Technologies Research Center (UTRC), and a subcontractor on-site at UTRC, kraftWork Systems Inc. The execution of the program started with bench-top experiments that were conducted at UTRC for extending kinetic mechanisms to HAT cycle temperature, pressure, and moisture conditions. The fundamental data generated in the bench-top experiments was incorporated into the analytical tools available at P&W to design the fuel injectors and combustors. The NETL then used the hardware to conduct combustion rig experiments to evaluate the performance of the combustion systems at elevated pressure and temperature conditions representative of the HAT cycle. The results were integrated into systems analysis done by kraftWork to verify that sufficient understanding of the technology had been achieved and that large-scale technological application and demonstration could be undertaken as follow-on activity. An optional program extended the

  4. Zinc air battery development for electric vehicles

    SciTech Connect

    Putt, R.A. )

    1990-05-01

    This document reports the progress and accomplishments of a 16 month program to develop a rechargeable zinc-air battery for electric vehicle propulsion, from October 1988 through January 1990. The program was the first stage in the transition of alkaline zinc electrode technology, invented at Lawrence Berkeley Laboratory, to private industry. The LBL invention teaches the use of a copper metal foam substrate for the zinc electrode, in combination with forced convection of electrolyte through the foam during battery operation. Research at LBL showed promise that this approach would avoid shape change (densification and dendrite growth), the primary failure mode of this electrode. The program comprised five tasks; (1) cell design, (2) capacity maximization, (3) cycle testing, (4) materials qualification, and (5) a cost/design study. The cell design contemplates a plate and frame stack, with alternating zinc and oxygen electrode frame assemblies between rigid end plates. A 200 Ah cell, as may be required for the EV application, would comprise a stack of five zinc and six oxygen electrode frame/assemblies. 8 figs., 2 tabs.

  5. Summary of the 2006 Hadronic Shower Simulation Workshop

    SciTech Connect

    Waters, Laurie S.

    2007-03-19

    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.

  6. 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.

  7. Development of an Air Brayton solar receiver

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Various receiver configurations and operating conditions were examined. The interface requirements between the receiver/concentrator/power module were addressed. Production cost estimates were obtained to determine the cost of the receiver during the 1980 timeframe. A conceptual design of an air Brayton solar receiver is presented based on the results. The following design goals were established: (1)peak thermal input power - 85 KWt; (2)receiver outlet air temperature - 1500 F; (3)receiver inlet air temperature - 1050 F; (4)design mass flow rate - 0.533 lb/sec; and (5)design receiver inlet pressure - 36.75 psia.

  8. Linear air-fuel sensor development

    SciTech Connect

    Garzon, F.; Miller, C.

    1996-12-14

    The electrochemical zirconia solid electrolyte oxygen sensor, is extensively used for monitoring oxygen concentrations in various fields. They are currently utilized in automobiles to monitor the exhaust gas composition and control the air-to-fuel ratio, thus reducing harmful emission components and improving fuel economy. Zirconia oxygen sensors, are divided into two classes of devices: (1) potentiometric or logarithmic air/fuel sensors; and (2) amperometric or linear air/fuel sensors. The potentiometric sensors are ideally suited to monitor the air-to-fuel ratio close to the complete combustion stoichiometry; a value of about 14.8 to 1 parts by volume. This occurs because the oxygen concentration changes by many orders of magnitude as the air/fuel ratio is varied through the stoichiometric value. However, the potentiometric sensor is not very sensitive to changes in oxygen partial pressure away from the stoichiometric point due to the logarithmic dependence of the output voltage signal on the oxygen partial pressure. It is often advantageous to operate gasoline power piston engines with excess combustion air; this improves fuel economy and reduces hydrocarbon emissions. To maintain stable combustion away from stoichiometry, and enable engines to operate in the excess oxygen (lean burn) region several limiting-current amperometric sensors have been reported. These sensors are based on the electrochemical oxygen ion pumping of a zirconia electrolyte. They typically show reproducible limiting current plateaus with an applied voltage caused by the gas diffusion overpotential at the cathode.

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

  10. 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.

  11. A possible new shower on Eridanus-Orion border

    NASA Astrophysics Data System (ADS)

    Šegon, Damir; Gural, Peter; Andreić, Željko; Vida, Denis; Skokić, Ivica; Novoselnik, Filip; Gržinić, Luciano

    2014-02-01

    Three showers on the border between constellations of Eridanus and Orion were found during extensive search for new showers in SonotaCo and CMN video meteor orbit databases. Our results suggest that two of these three showers represent  Eridanids shower (337 NUE), while third one represents separate possible new shower which has been named 6 Orionids (552 PSO).

  12. The development of effects-based air quality management regimes

    NASA Astrophysics Data System (ADS)

    Longhurst, J. W. S.; Irwin, J. G.; Chatterton, T. J.; Hayes, E. T.; Leksmono, N. S.; Symons, J. K.

    This paper considers the evolution of attempts to control and manage air pollution, principally but not exclusively focussing upon the challenge of managing air pollution in urban environments. The development and implementation of a range of air pollution control measures are considered. Initially the measures implemented primarily addressed point sources, a small number of fuel types and a limited number of pollutants. The adequacy of such a source-control approach is assessed within the context of a changing and challenging air pollution climate. An assessment of air quality management in the United Kingdom over a 50-year timeframe exemplifies the range of issues and challenges in contemporary air quality management. The need for new approaches is explored and the development and implementation of an effects-based, risk management system for air quality regulation is evaluated.

  13. The IAU Meteor Shower Nomenclature Rules

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter

    2008-06-01

    The International Astronomical Union at its 2006 General Assembly in Prague has adopted a set of rules for meteor shower nomenclature, a working list with designated names (with IAU numbers and three-letter codes), and established a Task Group for Meteor Shower Nomenclature in Commission 22 (Meteors and Interplanetary Dust) to help define which meteor showers exist from well defined groups of meteoroids from a single parent body.

  14. A computer system to analyze showers in nuclear emulsions: Center Director's discretionary fund report

    NASA Technical Reports Server (NTRS)

    Meegan, C. A.; Fountain, W. F.; Berry, F. A., Jr.

    1987-01-01

    A system to rapidly digitize data from showers in nuclear emulsions is described. A TV camera views the emulsions though a microscope. The TV output is superimposed on the monitor of a minicomputer. The operator uses the computer's graphics capability to mark the positions of particle tracks. The coordinates of each track are stored on a disk. The computer then predicts the coordinates of each track through successive layers of emulsion. The operator, guided by the predictions, thus tracks and stores the development of the shower. The system provides a significant improvement over purely manual methods of recording shower development in nuclear emulsion stacks.

  15. Development of a multiple-microhole aerostatic air bearing system

    NASA Astrophysics Data System (ADS)

    Fan, Kuang-Chao; Ho, Chi-Chung; Mou, Jong-I.

    2002-09-01

    New types of aerostatic air bearing and linear slide systems have been developed. The prototype of a multiple-microhole, instead of a porous-type, air bearing was developed and the surface roughness was improved by finished process. Instead of the conventional drilling process, the air bearing pads were fabricated by using microfabrication technology in this research. The spectral element method was employed to simulate the pressure distribution of air bearing and a comparison was made with experimental results. A granite straight edge was used as linear slide to guide the moving table that was supported by the developed air bearing system. A laser interferometer system was used to assess the performance of the stage.

  16. 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.

  17. RESPIRATORY EPIDEMIOLOGY OF HOUSEHOLD AIR POLLUTION EXPOSURES IN DEVELOPING COUNTRIES

    EPA Science Inventory

    Acute and chronic respiratory diseases impose a huge public health burden in the developing world. A large and growing body of scientific evidence indicates that household air pollution exposures contribute substantially to this burden. The most important source of indoor air p...

  18. APEX (Air Pollution Exercise) Volume 14; Developer's Manual No. 4.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Developer's Manual No. 4 is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two sections, which are the same in each of…

  19. APEX (Air Pollution Exercise) Volume 17: Developer's Manual No. 7.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Developer's Manual No. 7 is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two sections, which are the same in each of…

  20. APEX (Air Pollution Exercise) Volume 11: Developer's Manual No. 1.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Developer's Manual No. 1 is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two sections, which are the same in each of…

  1. APEX (Air Pollution Exercise) Volume 13: Developer's Manual No. 3.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Developer's Manual No. 3 is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two sections, which are the same in each of…

  2. APEX (Air Pollution Exercise) Volume 12: Developer's Manual No. 2.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Developer's Manual No. 2 is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two sections, which are the same in each of…

  3. APEX (Air Pollution Exercise) Volume 16: Developer's Manual No. 6.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Developer's Manual No. 6 is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two sections, which are the same in each of…

  4. APEX (Air Pollution Exercise) Volume 15: Developer's Manual No. 5.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Developer's Manual No. 5 is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two section, which are the same in each of…

  5. 49 CFR 228.321 - Showering facilities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... remove waste water and facilitate cleaning; (3) All junctions of the curbing and the floor must be sealed... shower room must be smooth and impervious to the height of splash. (d) Water. An adequate supply of hot and cold running potable water must be provided for showering purposes. The water supplied to a...

  6. 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.

  7. Introduction to Parton-Shower Event Generators

    NASA Astrophysics Data System (ADS)

    Höche, Stefan

    This lecture discusses the physics implemented by Monte Carlo event generators for hadron colliders. It details the construction of parton showers and the matching of parton showers to fixed-order calculations at higher orders in perturbative QCD. It also discusses approaches to merge calculations for a varying number of jets, the interface to the underlying event and hadronization.

  8. 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.

  9. LTA - Recent developments. [Lighter Than Air ships

    NASA Technical Reports Server (NTRS)

    Mayer, N. J.

    1977-01-01

    NASA-sponsored studies of existing and new LTA missions showed that airships looked very promising for some two dozen civil and military applications. These include surveillance of rural and urban areas, in the form of forest and police patrols; transport of very heavy large-volume maritime, industrial, and military payloads; coastal patrol and sea control; seismographic surveys; air pollution monitoring; and moving goods to remote areas; along with a number of less important but still attractive missions. A figure of merit of productivity (payload weight, ton moles per hour) was used to compare airships of various type and size. In each case, this criterion established an index of efficiency for evaluating not only conceptual approaches but also modes of flight. Some, in part unexpected, results of these studies are described.

  10. Electromagnetic Shower Reconstruction in Emulsion Cloud Chamber

    NASA Astrophysics Data System (ADS)

    Esposito, L. S.

    2006-04-01

    Atmospheric neutrino data from the MACRO, Soudan II and Super-Kamiokande experiments are consistent with the hypothesis of νμ → ντ oscillations. The OPERA experiment aims to prove definitively this hypothesis with the direct observation of ντ neutrinos in the νμ beam produced at CERN (CNGS). The apparatus, in construction at the Gran Sasso Underground Laboratory, is equipped with electronic detectors and a sensitive target. The target is highly segmented in units, bricks, composed of alternate nuclear emulsion plates and lead sheets. An algorithm to reconstruct electromagnetic showers in a brick was developed. The algorithm was optimized using experimental data from 1, 3 and 6 GeV electron exposures and cross-checked with detailed Monte Carlo simulations. Finally, a neural network was used as electron/pion separator.

  11. NLO matrix elements and truncated showers

    NASA Astrophysics Data System (ADS)

    Höche, Stefan; Krauss, Frank; Schönherr, Marek; Siegert, Frank

    2011-08-01

    In this publication, an algorithm is presented that combines the ME+PS approach to merge sequences of tree-level matrix elements into inclusive event samples [1] with the P owheg method, which combines exact next-to-leading order matrix element results with the parton shower [2, 3]. It was developed in parallel to the ME nloPS technique discussed in [4] and has been implemented in the event generator S herpa [5, 6]. The benefits of this approach are exemplified by some first predictions for a number of processes, namely the production of jets in e + e --annihilation, in deep-inelastic ep scattering, in association with single W, Z or Higgs bosons, and with vector boson pairs at hadron colliders.

  12. 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 ...

  13. DEVELOPMENT OF A LOW PRESSURE, AIR ATOMIZED OIL BURNER WITH HIGH ATOMIZER AIR FLOW

    SciTech Connect

    BUTCHER,T.A.

    1998-01-01

    This report describes technical advances made to the concept of a low pressure, air atomized oil burner for home heating applications. Currently all oil burners on the market are of the pressure atomized, retention head type. These burners have a lower firing rate limit of about 0.5 gallons per hour of oil, due to reliability problems related to small flow passage sizes. High pressure air atomized burners have been shown to be one route to avoid this problem but air compressor cost and reliability have practically eliminated this approach. With the low pressure air atomized burner the air required for atomization can be provided by a fan at 5--8 inches of water pressure. A burner using this concept, termed the Fan-Atomized Burner or FAB has been developed and is currently being commercialized. In the head of the FAB, the combustion air is divided into three parts, much like a conventional retention head burner. This report describes development work on a new concept in which 100% of the air from the fan goes through the atomizer. The primary advantage of this approach is a great simplification of the head design. A nozzle specifically sized for this concept was built and is described in the report. Basic flow pressure tests, cold air velocity profiles, and atomization performance have been measured. A burner head/flame tube has been developed which promotes a torroidal recirculation zone near the nozzle for flame stability. The burner head has been tested in several furnace and boiler applications over the tiring rate range 0.2 to 0.28 gallons per hour. In all cases the burner can operate with very low excess air levels (under 10%) without producing smoke. Flue gas NO{sub x} concentration varied from 42 to 62 ppm at 3% 0{sub 2}. The concept is seen as having significant potential and planned development efforts are discussed.

  14. Developing a Great Lakes air toxic emission inventory for Ontario

    SciTech Connect

    Wong, P.; Wong, S.; Bobet, E.; Wong, S.; Doan, C.

    1997-12-31

    In meeting the increasing needs for an emission inventory of toxic air pollutants around the Ontario portion of the Great Lakes Region, this pilot study was the first phase of the development of a comprehensive toxic air pollutant emission inventory system which will meet the demand from the Ontario domestic and international environmental management programs. In the ongoing development of a toxic air pollutant emission inventory for Ontario, source-release information gaps and emission estimation methodology deficiencies have been identified for future improvement. The state-of-the-art Regional Air Pollutant Inventory Development System (RAPIDS), being developed by the eight Great Lakes states and under the project management of the Great Lakes Commission, was used in this study to compile the emission inventories of selected toxic air pollutants from point, area and mobile sources for 1990. Other emission inventory related models/tools used in this study included the MOBILE 5C (modified version of US MOBILE 5a by Environment Canada), PART5 and other Environment Canada or Ontario specific emission profiles. An emission inventory of toxic air pollutants from the Great Lakes Commission`s 49 targeted compounds and the Canada-Ontario Agreement Respecting the Great Lakes Basin Ecosystem (COA) was developed in this study. This study identified major point source and area source categories that contributed significant emissions of the specified toxic air pollutants. This study demonstrated that RAPIDS can be used as a framework for the development of an Ontario toxic air pollutant emission inventory. However, further refinement of the RAPIDS system, the emission factors, and source specific toxic air speciation profiles would be required.

  15. 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

  16. AIRS-Light instrument concept and critical technology development

    NASA Astrophysics Data System (ADS)

    Maschhoff, Kevin R.

    2002-12-01

    Understanding Earth's climate, atmospheric transport mechanisms, and the hydrologic cycle requires a precise knowledge of global atmospheric circulation, temperature profiles, and water vapor distribution. The accuracy of advanced sounders such as AIRS/AMSU/HSB on NASA's Aqua spacecraft can match radiosonde accuracy. It is essential to fold those capabilities fully into the NPOESS, enabling soundings of radiosonde accuracy every 6 hours around the globe on an operational basis. However, the size, mass, power demands, and thermal characteristics of the Aqua sounding instrument suite cannot be accommodated on the NPOESS spacecraft. AIRS-Light is an instrument concept, developed under the Instrument Incubator Program, which provides IR sounding performance identical to the AIRS instrument but uses advances in HgCdTe FPA technology and pulse tube cooler technology, as well as design changes, to dramatically reduce the size, mass, and power demand, allowing AIRS-Light to meet all NPOESS spacecraft interface requirements. The AIRS-Light Instrument Incubator program fostered the development of photovoltaic-mode HgCdTe detector array technology for the 13.5-15.4 μm band covered by photoconductive-mode HgCdTe arrays in AIRS, achieved state of the art results in this band, and substantially reduced the development risk for this last new technology needed for AIRS-Light implementation.

  17. Development of a distributed air pollutant dry deposition modeling framework.

    PubMed

    Hirabayashi, Satoshi; Kroll, Charles N; Nowak, David J

    2012-12-01

    A distributed air pollutant dry deposition modeling system was developed with a geographic information system (GIS) to enhance the functionality of i-Tree Eco (i-Tree, 2011). With the developed system, temperature, leaf area index (LAI) and air pollutant concentration in a spatially distributed form can be estimated, and based on these and other input variables, dry deposition of carbon monoxide (CO), nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), and particulate matter less than 10 microns (PM10) to trees can be spatially quantified. Employing nationally available road network, traffic volume, air pollutant emission/measurement and meteorological data, the developed system provides a framework for the U.S. city managers to identify spatial patterns of urban forest and locate potential areas for future urban forest planting and protection to improve air quality. To exhibit the usability of the framework, a case study was performed for July and August of 2005 in Baltimore, MD. PMID:22858662

  18. AIRS-Light Instrument Concept and Critical Technology Development

    NASA Technical Reports Server (NTRS)

    Maschhoff, Kevin

    2001-01-01

    Understanding Earth's climate, atmospheric transport mechanisms, and the hydrologic cycle requires a precise knowledge of global atmospheric circulation, temperature profiles, and water vapor distribution. The accuracy of advanced sounders such as AIRS/AMSU/HSB on NASA's Aqua spacecraft can match radiosonde accuracy. It is essential to fold those capabilities fully into the NPOESS, enabling soundings of radiosonde accuracy, every 6 hours around the globe on an operational basis. However, the size, mass, power demands, and thermal characteristics of the Aqua sounding instrument suite cannot be accommodated on the NPOESS spacecraft. AIRS-Light is an instrument concept, developed under the Instrument Incubator Program, which provides IR sounding performance identical to the AIRS instrument, but uses advances in HgCdTe FPA technology and pulse tube cooler technology, as well as design changes to dramatically reduce the size, mass, and power demand, allowing AIRS-Light to meet all NPOESS spacecraft interface requirements. The instrument concept includes substantial re-use of AIRS component designs, including the complex AIRS FPA, to reduce development risk and cost. The AIRS-Light Instrument Incubator program fostered the development of photovoltaic-mode HgCdTe detector array technology for the 13.5-15.4 micron band covered by photoconductive-mode HgCdTe arrays in AIRS, achieved state of the art results in this band, and substantially reduced the development risk for this last new technology needed for AIRS-Light implementation, A demonstration of a prototype 14.5-15.4 micron band IRFPA in a reduced heat-load dewar together with the IMAS pulse tube cryocooler is in progress.

  19. Cleaning patient shower facilities: a novel approach to reducing patient exposure to aerosolized Aspergillus species and other opportunistic molds.

    PubMed

    Anaissie, Elias J; Stratton, Shawna L; Dignani, Maria Cecilia; Lee, Choon-Kee; Mahfouz, Tahsine H; Rex, John H; Summerbell, Richard C; Walsh, Thomas J

    2002-10-15

    We previously have demonstrated that the hospital water-distribution system could be a reservoir for airborne molds that leads to secondary aerosolization of these molds in patient shower facilities. In this report, we show that cleaning the floors of patient shower facilities in a bone marrow transplantation unit reduced the mean air concentrations of molds, including Aspergillus species (from 12 cfu/m3 to 4 cfu/m3; P=.0047). PMID:12355397

  20. 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.

  1. [Impact of air pollution on the development of asthma].

    PubMed

    Sánchez, Jorge; Caraballo, Luis

    2015-01-01

    Air pollution affects the origin and evolution of respiratory diseases. The increased frequency of asthma in recent years has been associated with growth air pollutants and small particles produced from the combustion of petroleum or cigarette smoke. Some mechanisms of how these contaminants can influence asthma and other allergic diseases are known: 1) acting as irritating on alveolar epithelial cells, 2) actin as adjuvant for allergens inflammation, 3) and epigenetic mechanisms. In this review, we discuss the pathophysiological mechanisms by which air pollutants become risk factors for the development of asthma and other allergic diseases. PMID:26556664

  2. Developing of a New Atmospheric Ionizing Radiation (AIR) Model

    NASA Technical Reports Server (NTRS)

    Clem, John M.; deAngelis, Giovanni; Goldhagen, Paul; Wilson, John W.

    2003-01-01

    As a result of the research leading to the 1998 AIR workshop and the subsequent analysis, the neutron issues posed by Foelsche et al. and further analyzed by Hajnal have been adequately resolved. We are now engaged in developing a new atmospheric ionizing radiation (AIR) model for use in epidemiological studies and air transportation safety assessment. A team was formed to examine a promising code using the basic FLUKA software but with modifications to allow multiple charged ion breakup effects. A limited dataset of the ER-2 measurements and other cosmic ray data will be used to evaluate the use of this code.

  3. Progress in development of flexible metal-air batteries

    NASA Astrophysics Data System (ADS)

    Sumboja, Afriyanti; Ge, Xiaoming; Zong, Yun; Liu, Zhaolin

    2016-04-01

    Flexible electronics has gained great interest in emerging wearable or rolling-up gadgets, such as foldable displays, electronic papers, and other personal multimedia devices. Subsequently, there is a need to develop energy storage devices that are pliable, inexpensive, and lightweight. Metal-air batteries have been identified as one of alternative energy storages for cost effective and high energy density applications. They offer cheaper production cost and higher energy density than most of the currently available battery technologies. Thus, they are promising candidates for flexible energy storage devices. Flexible metal-air batteries have to maintain their performances during various mechanical deformations. To date, efforts have been focused on fabricating flexible components for metal-air batteries. This review presents a brief introduction to the field, followed by progress on development of flexible electrolytes, electrodes, and prototype devices. Challenges and outlook towards the practical use of metal-air batteries are given in the last part.

  4. Current developments lighter than air systems. [heavy lift airships

    NASA Technical Reports Server (NTRS)

    Mayer, N. J.

    1981-01-01

    Lighter than air aircraft (LTA) developments and research in the United States and other countries are reviewed. The emphasis in the U.S. is on VTOL airships capable of heavy lift, and on long endurance types for coastal maritime patrol. Design concepts include hybrids which combine heavier than air and LTA components and characteristics. Research programs are concentrated on aerodynamics, flight dynamics, and control of hybrid types.

  5. ANN based Estimation of Ultra High Energy (UHE) Shower Size using Radio Data

    NASA Astrophysics Data System (ADS)

    Sinha, Kalpana Roy; Datta, Pranayee; Sarma, Kandarpa Kumar

    2013-02-01

    Size estimation is a challenging area in the field of Ultra High Energy (UHE) showers where actual measurements are always associated with uncertainty of events and imperfections in detection mechanisms. The subtle variations resulting out of such factors incorporate certain random behaviour in the readings provided by shower detectors for subsequent processing. Field strength recorded by radio detectors may also be affected by this statistical nature. Hence there is a necessity of development of a system which can remain immune to such random behaviour and provide resilient readings to subsequent stages. Here, we propose a system based on Artificial Neural Network (ANN) which accepts radio field strength recorded by radio detectors and provides estimates of shower sizes in the UHE region. The ANN in feed-forward form is trained with a range of shower events with which it can effectively handle the randomness observed in the detector reading due to imperfections in the experimental apparatus and related set-up.

  6. Opportunistic Pathogens Mycobacterium Avium Complex (MAC) and Legionella spp. Colonise Model Shower

    PubMed Central

    Whiley, Harriet; Giglio, Steven; Bentham, Richard

    2015-01-01

    Legionella spp. and Mycobacterium avium complex (MAC) are opportunistic pathogens of public health concern. Hot water systems, including showers, have been identified as a potential source of infection. This paper describes the colonization of Legionella and MAC on the flexible tubing within a model potable shower system, utilizing thermostatic mixing and a flexible shower head. A MAC qPCR method of enumeration was also developed. MAC and Legionella spp. were detected within the biofilm at maximum concentrations of 7.0 × 104 and 2.0 × 103 copies/cm2 PVC tubing respectively. No significant changes were observed between sample of the flexible shower tubing that dried between uses and those that remained filled with water. This suggested the “unhooking” showerheads and allowing them to dry is not an effective method to reduce the risk of Legionella or MAC colonisation. PMID:26213977

  7. Development of wireless sensor network for monitoring indoor air pollutant

    NASA Astrophysics Data System (ADS)

    Saad, Shaharil Mad; Shakaff, Ali Yeon Md; Saad, Abdul Rahman Mohd; Yusof @ Kamarudin, Azman Muhamad

    2015-05-01

    The air that we breathe with everyday contains variety of contaminants and particles. Some of these contaminants and particles are hazardous to human health. Most of the people don't realize that the content of air they being exposed to whether it was a good or bad air quality. The air quality whether in indoor or outdoor environment can be influenced by physical factors like dust particles, gaseous pollutants (including carbon dioxide, carbon monoxide and volatile organic compounds) and biological like molds and bacteria growth which largely depend on temperature and humidity condition of a room. These kinds of pollutants can affect human health, physical reaction, comfort or work performance. In this study, a wireless sensor network (WSN) monitoring system for monitor air pollutant in indoor environment was developed. The system was divided into three parts: web-based interface program, sensing module and a base station. The measured data was displayed on the web which is can be accessed by the user. The result shows that the overall measured parameters were meet the acceptable limit, requirement and criteria of indoor air pollution inside the building. The research can be used to improve the indoor air quality level in order to create a comfortable working and healthy environment for the occupants inside the building.

  8. A Meteor Shower Origin for Martian Methane

    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.

    2015-07-01

    We present and discuss the hypothesis that martian methane arises from a meteor shower source. Infall material produces methane by UV photolysis, generating localized plumes that occur after Mars/comet orbit interactions. This hypothesis is testable.

  9. 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...

  10. Low Temperature Atmospheric Pressure Plasma Sterilization Shower

    NASA Astrophysics Data System (ADS)

    Gandhiraman, R. P.; Beeler, D.; Meyyappan, M.; Khare, B. N.

    2012-10-01

    Low-temperature atmospheric pressure plasma sterilization shower to address both forward and backward biological contamination issues is presented. The molecular effects of plasma exposure required to sterilize microorganisms is also analysed.

  11. 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.

  12. 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.

  13. 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.

  14. Developing a risk-based air quality health index

    NASA Astrophysics Data System (ADS)

    Wong, Tze Wai; Tam, Wilson Wai San; Yu, Ignatius Tak Sun; Lau, Alexis Kai Hon; Pang, Sik Wing; Wong, Andromeda H. S.

    2013-09-01

    We developed a risk-based, multi-pollutant air quality health index (AQHI) reporting system in Hong Kong, based on the Canadian approach. We performed time series studies to obtain the relative risks of hospital admissions for respiratory and cardiovascular diseases associated with four air pollutants: sulphur dioxide, nitrogen dioxide, ozone, and particulate matter with an aerodynamic diameter less than 10 μm (PM10). We then calculated the sum of excess risks of the hospital admissions associated with these air pollutants. The cut-off points of the summed excess risk, for the issuance of different health warnings, were based on the concentrations of these pollutants recommended as short-term Air Quality Guidelines by the World Health Organization. The excess risks were adjusted downwards for young children and the elderly. Health risk was grouped into five categories and sub-divided into eleven bands, with equal increments in excess risk from band 1 up to band 10 (the 11th band is 'band 10+'). We developed health warning messages for the general public, including at-risk groups: young children, the elderly, and people with pre-existing cardiac or respiratory diseases. The new system addressed two major shortcomings of the current standard-based system; namely, the time lag between a sudden rise in air pollutant concentrations and the issue of a health warning, and the reliance on one dominant pollutant to calculate the index. Hence, the AQHI represents an improvement over Hong Kong's existing air pollution index.

  15. Development and test of the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Morse, Paul G.; Bates, Jerry C.; Miller, Christopher R.; Chahine, Moustafa T.; O'Callaghan, Fred; Aumann, Hartmut H.; Karnik, Avinash R.

    1999-12-01

    The Atmospheric Infrared Sounder (AIRS) has been developed for the NASA Earth Observing System (EOS) program for a scheduled launch on the EOS PM-1 spacecraft in December 2000. AIRS, working in concert with complementary microwave instrumentation on EOS PM-1 is designed to provide both new and more accurate data about the atmosphere, land and oceans for application to NASA climate studies and NOAA and DOD weather prediction. Among the important parameters to be derived from AIRS observations are atmospheric temperature profiles with an average accuracy of 1 K in 1 kilometer (km) layers in the troposphere, humidity profiles to 10% accuracy and surface temperatures with an average accuracy of 0.5 K. The AIRS measurement technique is based on passive IR remote sensing using a precisely calibrated, high spectral resolution grating spectrometer operating in the 3.7 - 15.4 micrometer region. The instrument concept uses a passively cooled multi- aperture echelle array spectrometer approach in combination with advanced state of the art focal plane and cryogenic refrigerator technology to achieve unparalleled performance capability in a practical long life configuration. The AIRS instrument, which has been under development since 1991, has been fully integrated and has completed successfully a comprehensive performance verification program. Performance verification included thermal vacuum testing, environmental qualification and a full range of spatial, spectral and radiometric calibrations, which have demonstrated outstanding spectrometric performance. This paper provides a brief overview of the AIRS mission and instrument design along with key results from the test program.

  16. Pioneer developments in self-contained air conditioning

    SciTech Connect

    Steinfeld, H.K.

    1986-01-01

    This is a story covering a chapter in the air conditioning industry when that industry was young. It had created the science through the inventions of Dr. Carrier and had developed the art of large systems to a high degree. But prior to 1930, only big jobs were installed, in all of which the air was pre-conditioned by sprays of water. Air conditioning solely for the benefit of the ordinary citizen was not available, and the progress of developing small equipment was lacking. It was only with the invention of ''Freon 12'' in 1930 by Thomas Midgley that all pieces seemed to fall into place for the design of self-contained units. Large companies and small entrepreneurs were ready to enter the field and combine newly developed components like hermetic compressors, improved electrical equipment, capacitors, etc., and lightweight finned coils.

  17. Exploiting the geomagnetic distortion of inclined atmospheric showers

    NASA Astrophysics Data System (ADS)

    Billoir, Pierre; Settimo, Mariangela; Blanco, Miguel

    2016-02-01

    We propose a novel approach to the determination of the nature of ultra-high energy cosmic rays by exploiting the geomagnetic deviation of muons in nearly horizontal showers. The distribution of muons at ground level is well described by a simple parameterization providing a few shape parameters tightly correlated to Xmaxμ, the depth of maximal muon production, which is a mass indicator tightly correlated to the usual parameter Xmax, the depth of maximal development of the shower. We show that some constraints can be set on the predictions of hadronic models, especially by combining the geomagnetic distortion with standard measurements of the longitudinal profile. We discuss the precision needed to obtain significant results, and we propose a schematic layout of a detector.

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

    PubMed

    Schoen, Mary E; Ashbolt, Nicholas J

    2011-11-15

    An exposure model was constructed to predict the critical Legionella densities in an engineered water system that result in infection from inhalation of aerosols containing the pathogen while showering. The model predicted the Legionella densities in the shower air, water and in-premise plumbing biofilm that might result in a deposited dose of Legionella in the alveolar region of the lungs associated with infection for a routine showering event. Processes modeled included the detachment of biofilm-associated Legionella from the in-premise plumbing biofilm during a showering event, the partitioning of the pathogen from the shower water to the air, and the inhalation and deposition of particles in the lungs. The range of predicted critical Legionella densities in the air and water was compared to the available literature. The predictions were generally within the limited set of observations for air and water, with the exception of Legionella density within in-premise plumbing biofilms, for which there remains a lack of observations for comparison. Sensitivity analysis of the predicted results to possible changes in the uncertain input parameters identified the target deposited dose associated with infections, the pathogen air-water partitioning coefficient, and the quantity of detached biofilm from in-premise pluming surfaces as important parameters for additional data collection. In addition, the critical density of free-living protozoan hosts in the biofilm required to propagate the infectious Legionella was estimated. Together, this evidence can help to identify critical conditions that might lead to infection derived from pathogens within the biofilms of any plumbing system from which humans may be exposed to aerosols. PMID:21924754

  19. Transition radiation at radio frequencies from ultrahigh-energy neutrino-induced showers

    NASA Astrophysics Data System (ADS)

    Motloch, Pavel; Alvarez-Muñiz, Jaime; Privitera, Paolo; Zas, Enrique

    2016-02-01

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

  20. Development of a solar-powered residential air conditioner

    NASA Technical Reports Server (NTRS)

    1975-01-01

    An extensive review of the literature was conducted which was concerned with the characterization of systems and equipment that could be applicable to the development of solar-powered air conditioners based on the Rankine cycle approach, and the establishment of baseline data defining the performance, physical characteristics, and cost of systems using the LiBr/H2O absorption cycle.

  1. Air Force Officer Qualifying Test Form O: Development and Standardization.

    ERIC Educational Resources Information Center

    Rogers, Deborah L.; And Others

    This report presents the rationale, development, and standardization of the Air Force Officer Qualifying Test (AFOQT) Form O. The test is used to select individuals for officer commissioning programs, and candidates for pilot and navigator training. Form O contains 380 items organized in 16 subtests. All items are administered in a single test…

  2. Development of visual-display aid to air navigation

    NASA Technical Reports Server (NTRS)

    Matcovich, T. J.

    1973-01-01

    The developments are discussed in the design of a liquid-crystal, visual display, air navigation aid, which uses two VOR signals to locate the aircraft. The system concepts, liquid crystal materials, stability tests, and the electronic system are described. It is concluded that a navigational aid of this type is technically feasible, but not at the projected low cost.

  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. Developments in skirt systems for air cushion vehicles

    NASA Astrophysics Data System (ADS)

    Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

    The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

  5. 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

  6. Development of a field-portable air monitor for Lewisite

    SciTech Connect

    Aldstadt, J.H.; Martin, A.F.; Olson, D.C. |

    1996-03-01

    The focus of this research is the development of a prototype field-portable ambient-air monitor for measuring trace levels of volatile organoarsenicals. Lewisite (dichloro[2-chlorovinyl]arsine) is a chemical warfare agent developed during World War I and stockpiled on a large scale by the former Soviet Union. A continuous air monitor for Lewisite at the eight-hour time-weighted-average concentration (3 {mu}g/m{sup 3}) is necessary to protect the safety and health of arms control treaty inspectors. Flow injection is used to integrate an air sampling device based on liquid-phase extraction with a flow-through detector based on potentiometric stripping analysis. We describe a method for the sampling and preconcentration of organoarsenicals from ambient air by using a gas permeation membrane sampler. The sampler is designed to selectively preconcentrate analyte that permeates a silicone rubber membrane into a caustic carrier stream. Instrument design is described for the sampling and detection methodologies.

  7. Four possible new high-declination showers

    NASA Astrophysics Data System (ADS)

    Šegon, Damir; Gural, Peter; Andreiæ, Željko; Vida, Denis; Skokiæ, Ivica; Novoselnik, Filip

    2015-10-01

    Four possible new meteor showers described in this paper are last ones resulting from our search for new meteor showers. All four of them seem to be connected to known parent bodies, currently classified as asteroids. All orbits from which associations had been done are orbits calculated by UFOOrbit software. Mean orbital parameters were computed using simple arithmetic average in an iterative way until stable set of orbits was found. Catalogues from 2007 to 2011 (SonotaCo) and 2007 to 2010 (CMN) were used in calculations. The radiants' dispersion is in all cases large and no clear radiant drift may be seen, possibly due to the fact that meteoroid streams from these parent bodies suffer from significant perturbations and we see these showers at different solar longitudes from year to year.

  8. 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

  9. Jet fragmentation via recombination of parton showers

    NASA Astrophysics Data System (ADS)

    Han, Kyong Chol; Fries, Rainer J.; Ko, Che Ming

    2016-04-01

    We propose to model hadronization of parton showers in QCD jets through a hybrid approach involving quark recombination and string fragmentation. This is achieved by allowing gluons at the end of the perturbative shower evolution to undergo a nonperturbative splitting into quark and antiquark pairs, then applying a Monte Carlo version of instantaneous quark recombination, and finally subjecting remnant quarks (those which have not found a recombination partner) to Lund string fragmentation. When applied to parton showers from the pythia Monte Carlo event generator, the final hadron spectra from our calculation compare quite well to pythia jets that have been hadronized with the default Lund string fragmentation. Our new approach opens up the possibility to generalize hadronization to jets embedded in a quark gluon plasma.

  10. Measurement of parton shower observables with OPAL

    NASA Astrophysics Data System (ADS)

    Fischer, N.; Gieseke, S.; Kluth, S.; Plätzer, S.; Skands, P.

    2016-07-01

    A study of QCD coherence is presented based on a sample of about 397,000 e+e- hadronic annihilation events collected at √s = 91 GeV with the OPAL detector at LEP. The study is based on four recently proposed observables that are sensitive to coherence effects in the perturbative regime. The measurement of these observables is presented, along with a comparison with the predictions of different parton shower models. The models include both conventional parton shower models and dipole antenna models. Different ordering variables are used to investigate their influence on the predictions.

  11. Development of Refrigerant Change Indicator and Dirty Air Filter Sensor

    SciTech Connect

    Mei, V.

    2003-06-24

    The most common problems affecting residential and light commercial heating, ventilation, and air-conditioning (HVAC) systems are slow refrigerant leaks and dirty air filters. Equipment users are usually not aware of a problem until most of the refrigerant has escaped or the air filter is clogged with dirt. While a dirty air filter can be detected with a technology based on the air pressure differential across the filter, such as a ''whistling'' indicator, it is not easy to incorporate this technology into existing HVAC diagnostic equipment. Oak Ridge National Laboratory is developing a low-cost, nonintrusive refrigerant charge indicator and dirty air filter detection sensor. The sensors, based on temperature measurements, will be inexpensive and easy to incorporate into existing heat pumps and air conditioners. The refrigerant charge indicator is based on the fact that when refrigerant starts to leak, the evaporator coil temperature starts to drop and the level of liquid subcooling drops. When the coil temperature or liquid subcooling drops below a preset reading, a signal, such as a yellow warning light, can be activated to warn the equipment user that the system is undercharged. A further drop of coil temperature or liquid subcooling below another preset reading would trigger a second warning signal, such as a red warning light, to warn the equipment user that the unit now detects a leak and immediate action should be taken. The warning light cannot be turned off until it is re-set by a refrigeration repairman. To detect clogged air filters, two additional temperature sensors can be applied, one each across the evaporator. When the air filter is accumulating buildup, the temperature differential across the evaporator will increase because of the reduced airflow. When the temperature differential reaches a pre-set reading, a signal will be sent to the equipment user that the air filter needs to be changed. A traditional refrigerant charge indicator requires

  12. Development of air touch interface for floating 3D image in the air

    NASA Astrophysics Data System (ADS)

    Fukuda, Hiroyuki; Morimoto, Hiroyuki; Sakamoto, Kunio

    2007-09-01

    We developed a prototype virtual air touch interface system for interaction in the virtual 3D space. The spatial imaging display system provides the observer virtual 3D objects. These 3D images are floating in the air and one can directly touch objects or virtual images. To take mutual action we need to prepare the interface system which can recognize that the user moves his hand near the virtual objects. Because a conventional touch-panel system detects the user's operation on the display screen but the touching point differs from the actual displaying space, it is important to realize that the user can operate at the same space. A typical method is to use the computer vision. In this paper, the authors propose the interface system using a theremin which is a musical instrument having the unusual aspect of being controlled by the performer's hand motions near the antennas.

  13. Development of an air flow thermal balance calorimeter

    NASA Technical Reports Server (NTRS)

    Sherfey, J. M.

    1972-01-01

    An air flow calorimeter, based on the idea of balancing an unknown rate of heat evolution with a known rate of heat evolution, was developed. Under restricted conditions, the prototype system is capable of measuring thermal wattages from 10 milliwatts to 1 watt, with an error no greater than 1 percent. Data were obtained which reveal system weaknesses and point to modifications which would effect significant improvements.

  14. Multilevel Analysis of Air Pollution and Early Childhood Neurobehavioral Development

    PubMed Central

    Lin, Ching-Chun; Yang, Shih-Kuan; Lin, Kuan-Chia; Ho, Wen-Chao; Hsieh, Wu-Shiun; Shu, Bih-Ching; Chen, Pau-Chung

    2014-01-01

    To investigate the association between the ambient air pollution levels during the prenatal and postnatal stages and early childhood neurobehavioral development, our study recruited 533 mother-infant pairs from 11 towns in Taiwan. All study subjects were asked to complete childhood neurobehavioral development scales and questionnaires at 6 and 18 months. Air pollution, including particulate matter ≤10 μm (PM10), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and hydrocarbons, was measured at air quality monitoring stations in the towns where the subjects lived. Multilevel analyses were applied to assess the association between air pollution and childhood neurobehavioral development during pregnancy and when the children were 0 to 6 months, 7 to 12 months, and 13 to 18 months old. At 18 months, poor subclinical neurodevelopment in early childhood is associated with the average SO2 exposure of prenatal, during all trimesters of pregnancy and at postnatal ages up to 12 months (first trimester β = −0.083, se = 0.030; second and third trimester β = −0.114, se = 0.045; from birth to 12 months of age β = −0.091, se = 0.034). Furthermore, adverse gross motor below average scores at six months of age were associated with increased average non-methane hydrocarbon, (NMHC) levels during the second and third trimesters (β = −8.742, se = 3.512). Low-level SO2 exposure prenatally and up to twelve months postnatal could cause adverse neurobehavioral effects at 18 months of age. Maternal NMHC exposure during the 2nd and 3rd trimesters of pregnancy would be also associated with poor gross motor development in their children at 6 months of age. PMID:24992486

  15. Multilevel analysis of air pollution and early childhood neurobehavioral development.

    PubMed

    Lin, Ching-Chun; Yang, Shih-Kuan; Lin, Kuan-Chia; Ho, Wen-Chao; Hsieh, Wu-Shiun; Shu, Bih-Ching; Chen, Pau-Chung

    2014-07-01

    To investigate the association between the ambient air pollution levels during the prenatal and postnatal stages and early childhood neurobehavioral development, our study recruited 533 mother-infant pairs from 11 towns in Taiwan. All study subjects were asked to complete childhood neurobehavioral development scales and questionnaires at 6 and 18 months. Air pollution, including particulate matter ≤10 μm (PM10), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and hydrocarbons, was measured at air quality monitoring stations in the towns where the subjects lived. Multilevel analyses were applied to assess the association between air pollution and childhood neurobehavioral development during pregnancy and when the children were 0 to 6 months, 7 to 12 months, and 13 to 18 months old. At 18 months, poor subclinical neurodevelopment in early childhood is associated with the average SO2 exposure of prenatal, during all trimesters of pregnancy and at postnatal ages up to 12 months (first trimester β = -0.083, se = 0.030; second and third trimester β = -0.114, se = 0.045; from birth to 12 months of age β = -0.091, se = 0.034). Furthermore, adverse gross motor below average scores at six months of age were associated with increased average non-methane hydrocarbon, (NMHC) levels during the second and third trimesters (β = -8.742, se = 3.512). Low-level SO2 exposure prenatally and up to twelve months postnatal could cause adverse neurobehavioral effects at 18 months of age. Maternal NMHC exposure during the 2nd and 3rd trimesters of pregnancy would be also associated with poor gross motor development in their children at 6 months of age. PMID:24992486

  16. Developing Mental Models about Air Using Inquiry-Based Instruction with Kindergartners

    ERIC Educational Resources Information Center

    Van Hook, Stephen; Huziak, Tracy; Nowak, Katherine

    2005-01-01

    This study examines the development of mental models of air by kindergarten students after completing a series of hands-on, inquiry-based science lessons. The lessons focused on two properties of air: (1) that air takes up space and (2) that it is made of particles ("balls of air"). The students were interviewed about their ideas of air and about…

  17. 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.

  18. 46 CFR 153.216 - Shower and eyewash fountains.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Vessel Requirements § 153.216 Shower and eyewash fountains. (a) Each non-self-propelled ship must have a fixed or portable shower and eyewash fountain that operates during cargo transfer and meets paragraph (c... 46 Shipping 5 2010-10-01 2010-10-01 false Shower and eyewash fountains. 153.216 Section...

  19. Household air pollution and the sustainable development goals

    PubMed Central

    Jaakkola, Jouni JK

    2016-01-01

    Abstract Globally, 41% of households, over 2.8 billion people, rely on solid fuels (coal and biomass) for cooking and heating. In developing countries in Asia and sub-Saharan Africa where these fuels are predominantly used, women who are customarily responsible for cooking, and their young children, are most exposed to the resulting air pollution. Solid fuels are still in widespread use and it appears that intervention efforts are not keeping pace with population growth in developing countries. Here we pinpoint the challenges and identify opportunities for addressing household air pollution while mitigating global climate change and promoting the sustainable development goals. We recommend the following actions: implementation of the WHO indoor air quality guidelines on household fuel combustion; effective promotion and dissemination of improved cookstoves through formation of country alliances for clean cookstoves; expansion of liquefied petroleum gas production facilities and distribution networks; harnessing renewable energy potential; promotion of biogas production at both household and community level; ensuring improved ventilation of homes through education and enforcement of building standards; and exploiting opportunities in the health and other sectors for changing health-damaging cooking behaviour. PMID:26966333

  20. Zinc air battery development for electric vehicles. Final report

    SciTech Connect

    Putt, R.A.; Merry, G.W.

    1991-07-01

    This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/cm{sup 2}. By the end of the Phase I program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase II program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

  1. Household air pollution and the sustainable development goals.

    PubMed

    Amegah, Adeladza Kofi; Jaakkola, Jouni J K

    2016-03-01

    Globally, 41% of households, over 2.8 billion people, rely on solid fuels (coal and biomass) for cooking and heating. In developing countries in Asia and sub-Saharan Africa where these fuels are predominantly used, women who are customarily responsible for cooking, and their young children, are most exposed to the resulting air pollution. Solid fuels are still in widespread use and it appears that intervention efforts are not keeping pace with population growth in developing countries. Here we pinpoint the challenges and identify opportunities for addressing household air pollution while mitigating global climate change and promoting the sustainable development goals. We recommend the following actions: implementation of the WHO indoor air quality guidelines on household fuel combustion; effective promotion and dissemination of improved cookstoves through formation of country alliances for clean cookstoves; expansion of liquefied petroleum gas production facilities and distribution networks; harnessing renewable energy potential; promotion of biogas production at both household and community level; ensuring improved ventilation of homes through education and enforcement of building standards; and exploiting opportunities in the health and other sectors for changing health-damaging cooking behaviour. PMID:26966333

  2. Pollutant Dispersion in a Developing Valley Cold-Air Pool

    NASA Astrophysics Data System (ADS)

    Chemel, Charles; Burns, Paul

    2015-03-01

    Pollutants are trapped and accumulate within cold-air pools, thereby affecting air quality. A numerical model is used to quantify the role of cold-air-pooling processes in the dispersion of air pollution in a developing region of enhanced cooling within an Alpine valley under decoupled stable conditions. Results indicate that the negatively buoyant downslope flows transport and mix pollutants into the valley to depths that depend on the temperature deficit of the flow and the ambient temperature structure inside the valley. Along the slopes, pollutants are generally entrained above the region of enhanced cooling and detrained within the region of enhanced cooling largely above the ground-based inversion layer. The ability of the region of enhanced cooling to dilute pollutants is quantified. The analysis shows that the downslope flows fill the valley with air from above, which is then largely trapped within the region of enhanced cooling and that dilution depends on where the pollutants are emitted with respect to the positions of the top of the ground-based inversion layer and region of enhanced cooling, and on the slope wind speeds. Over the lower part of the slopes, the concentrations averaged across the region of enhanced cooling are proportional to the slope wind speeds where the pollutants are emitted, and diminish as the region of enhanced cooling deepens. Pollutants emitted within the ground-based inversion layer are largely trapped there. Pollutants emitted farther up the slopes detrain within the region of enhanced cooling above the ground-based inversion layer, although some fraction, increasing with distance from the top of the slopes, penetrates into the ground-based inversion layer.

  3. Fluorescence in air excited by electrons from a 90Sr source

    NASA Astrophysics Data System (ADS)

    Sakaki, N.; Watanabe, Y.; Nagano, M.; Kobayakawa, K.

    2008-11-01

    The air fluorescence technique is used to observe ultra-high energy cosmic rays (UHECRs). In this technique, fluorescence from air excited by electrons within an extensive air shower (EAS) under various pressure and temperature conditions is detected by a telescope. The primary energy of the UHECR is estimated from the amount of fluorescence. Since ground-based experiments, such as Fly's Eye, HiRes, Auger, Telescope Array, are carried out at high altitudes, the effects of water vapor may be negligible and the photon yields in dry air, which we have measured and reported so far, will be applicable. However, in case of space-based experiments such as JEM-EUSO, most events will be observed above the sea. Photon yields in moist air are measured with a 90Sr β source and compared to those in dry air at wavelengths of 337, 358 and 391 nm. The presence of water vapor considerably reduces the photon yield. The decrease in the photon yield in moist air should be taken into account to interpret the longitudinal development of EASs near the sea surface, although the effects around the shower maximum for most showers might be small.

  4. Indoor air pollution from unprocessed solid fuels in developing countries.

    PubMed

    Kaplan, Charlotte

    2010-01-01

    Approximately half of the world's population relies on biomass (primarily wood and agricultural residues) or coal fuels (collectively termed solid fuels) for heating, lighting, and cooking. The incomplete combustion of such materials releases byproducts with well-known adverse health effects, hence increasing the risk of many diseases and death. Among these conditions are acute respiratory infections, chronic obstructive pulmonary disease, heart disease, stroke, lung cancer, cataracts and blindness, tuberculosis, asthma, and adverse pregnancy outcomes. The International Agency for Research on Cancer has classified the indoor combustion of coal emissions as Group 1, a known carcinogen to humans. Indoor air pollution exposure is greatest in individuals who live in rural developing countries. Interventions have been limited and show only mixed results. To reduce the morbidity and mortality from indoor air pollution, countermeasures have to be developed that are practical, efficient, sustainable, and economical with involvement from the government, the commercial sector, and individuals. This review focuses on the contribution of solid fuels to indoor air pollution. PMID:21038757

  5. Development of an Air Transport Type A Fissile Package

    SciTech Connect

    Blanton, P.; Ebert, K.

    2011-07-13

    This paper presents the summary of testing by the Savannah River National Laboratory (SRNL) to support development of a light weight (<140 lbs) air transport qualified Type A Fissile Packaging. The package design incorporates features and materials specifically designed to minimize packaging weight. The light weight package is being designed to provide confinement to the contents when subjected to the normal and hypothetical conditions required of an air transportable Type A Fissile radioactive material shipping package. The objective of these tests was to provide design input to the final design for the LORX Type A Fissile Air Transport Packaging when subjected to the performance requirements of the drop, crush and puncture probe test of 10CFR71. The post test evaluation of the prototype packages indicates that all of the tested designs would satisfactorily confine the content within the packaging. The differences in the performance of the prototypes varied significantly depending on the core materials and their relative densities. Information gathered from these tests is being used to develop the final design for the Department of Homeland Security.

  6. Development of a southern oceanic air standard reference material.

    PubMed

    Rhoderick, George C; Kelley, Michael E; Miller, Walter R; Brailsford, Gordon; Possolo, Antonio

    2016-02-01

    In 2009, the United States Congress charged the National Institute of Standards and Technology (NIST) with supporting climate change research. As part of this effort, the Gas Sensing Metrology Group at NIST began developing new gas standard mixtures for greenhouse gas mixtures relevant to atmospheric measurements. Suites of gravimetrically prepared primary standard mixtures (PSMs) were prepared at ambient concentration levels for carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in a dry-air balance. In parallel, 30 gas cylinders were filled, by the National Institute of Water and Atmospheric Research (NIWA) in Wellington, New Zealand, to high pressure from pristine southern oceanic air at Baring Head, New Zealand, and shipped to NIST. Using spectroscopic instrumentation, NIST analyzed the 30 cylinder samples for mole fractions of CO2, CH4, and N2O. Certified values were assigned to these mixtures by calibrating the instrumentation with the PSM suites that were recently developed at NIST. These mixtures became NIST Standard Reference Material (SRM) 1721 Southern Oceanic Air and are certified for ambient mole fraction, the first of their kind for NIST. The relative expanded uncertainties corresponding to coverage intervals with 95% probability are no larger than 0.06% of the certified values, representing the smallest uncertainties to date ever assigned to an NIST gas SRM. PMID:26650733

  7. Development of a Fieldable Air-Coupled Ultrasonic Inspection System

    NASA Astrophysics Data System (ADS)

    Peters, J. J.; Barnard, D. J.; Hsu, D. K.

    2004-02-01

    This paper describes the development of a non-mechanically encoded, simple, field-worthy air-coupled ultrasonic scanning system that gives quantitative information about the size of damage and underlying structure in composite and aluminum aerospace structures. The system consists of the AIRSCAN® air-coupled ultrasonic testing system, the Flock of Birds® real-time motion tracking equipment, a lightweight composite yoke, and laptop PC with data acquisition and processing software. Through transmission C-scan images are generated manually by moving transducers attached to a yoke across the part's surface. The prototype has produced images for a variety of aircraft composite and metal honeycomb structures containing flaws, damages, and repairs. Field tests on commercial and military aircraft as well as rotor blades have begun. Initial test results are shown.

  8. 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

  9. Comet outbursts and the meteor showers

    NASA Astrophysics Data System (ADS)

    Guliyev, A. S.; Kokhirova, G. I.; Poladova, U. D.

    2014-07-01

    The features of 116 comets that have shown an outbursts in their brightness, are considered in the paper. The hypothesis on that the outburst in activity of comets are caused by their passing through meteoroid streams is studied. For this purpose the orbital elements of such comets relative to the planes of motion of 68 meteor showers from Cook's catalogue are analyzed. It was found that four of the nearest and distant nodes of comet orbits relative to the planes of motion of nine meteor showers exceeds the average statistical background with confidence probability from 0.90 to 0.95, and more than 0.95, respectively. The October Draconids, Aurigids, kappa-Serpentids, delta-Draconids, sigma-Hydrids}, Coma Berenicids, Leonids, Leo Minorids, and Perseids showers are the most effective. The results of calculation show that often, the comets outbursts may be caused by collisions of comets with meteoroids under the passing through the meteoroid streams that are producing listed meteor showers as well as solar activity.

  10. Development of an air-atomized oil burner

    SciTech Connect

    Butcher, T.A.; Celebi, Y.

    1996-06-01

    A new concept for the design of a residential oil burner is presented involving a low pressure, air atomizing nozzle. Advantages of this approach, relative to conventional, pressure atomized burners include: ability to operate at very low excess air levels without smoke, ability to operate at low (and possibly variable) rates, reduced boiler fouling, and low NO{sub x}. The nozzle used is a low pressure, airblast atomizer which can achieve fuel spray drop sizes similar to conventional nozzles and very good combustion performance with air pressure as low as 5 inches of water (1.24 kPa). A burner head has been developed for this nozzle and combustion test results are presented in a wide variety of equipment including cast iron and steel boilers, warm air furnaces, and water heaters over the firing rate range 0.25 gph to 1.0 gph (10 to 41 kW). Beyond the nozzle and combustion head the burner system must be developed and two approaches have been taken. The first involves a small, brushless DC motor/fan combination which uses high fan speed to achieve air pressures from 7 to 9 inches of water (1.74 to 2.24 kPa). Fuel is delivered to the atomizer at less than 1 psig (6.9 kPa) using a solenoid pump and flow metering orifice. At 0.35 gph (14 kW) the electric power draw of this burner is less than 100 watts. In a second configuration a conventional motor is used with a single stage fan which develops 5 to 6 inches of water pressure (1.24 to 1.50 kPa) at similar firing rates. This burner uses a conventional type fuel pump and metering orifice to deliver fuel. The fuel pump is driven by the fan motor, very much like a conventional burner. This second configuration is seen as more attractive to the heating industry and is now being commercialized. Field tests with this burner have been conducted at 0.35 gph (14 kW) with a side-wall vented boiler/water storage tank combination.

  11. Development of a Northern Continental Air Standard Reference Material.

    PubMed

    Rhoderick, George C; Kitzis, Duane R; Kelley, Michael E; Miller, Walter R; Hall, Bradley D; Dlugokencky, Edward J; Tans, Pieter P; Possolo, Antonio; Carney, Jennifer

    2016-03-15

    The National Institute of Standards and Technology (NIST) recently began to develop standard mixtures of greenhouse gases as part of a broad program mandated by the 2009 United States Congress to support research in climate change. To this end, NIST developed suites of gravimetrically assigned primary standard mixtures (PSMs) comprising carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in a dry-natural air balance at ambient mole fraction levels. In parallel, the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, charged 30 aluminum gas cylinders with northern hemisphere air at Niwot Ridge, Colorado. These mixtures, which constitute NIST Standard Reference Material (SRM) 1720 Northern Continental Air, were certified by NIST for ambient mole fractions of CO2, CH4, and N2O relative to NIST PSMs. NOAA-assigned values are also provided as information in support of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) Program for CO2, CH4, and N2O, since NOAA serves as the WMO Central Calibration Laboratory (CCL) for CO2, CH4, and N2O. Relative expanded uncertainties at the 95% confidence interval are <±0.06% of the certified values for CO2 and N2O and <0.2% for CH4, which represents the smallest relative uncertainties specified to date for a gaseous SRM produced by NIST. Agreement between the NOAA (WMO/GAW) and NIST values based on their respective calibration standards suites is within 0.05%, 0.13%, and 0.06% for CO2, CH4, and N2O, respectively. This collaborative development effort also represents the first of its kind for a gaseous SRM developed by NIST. PMID:26890890

  12. Activity and observability of meteor showers throughout the year

    NASA Astrophysics Data System (ADS)

    Zimnikoval, Peter

    2014-02-01

    Diagrams on the poster present the activity periods of meteor showers as well as the rising and setting times of meteor shower radiants. Plotted are sunrises, sunsets and the period of twilight. It was constructed according to data from the IMO Meteor Shower Working List. More active showers are displayed in red and less active showers in green. The diagrams are calculated for geographic latitudes of 40° N, 0° and 40° S. The time scale is given as local time at the relevant zonal meridian and supplemented by local daylight saving time. The diagrams contain rounded values of solar longitude J2000. The star chart shows the radiant positions and drift of IMO meteor showers while the other diagrams display shower activity and date of maximum.

  13. Managing air quality in a rapidly developing nation: China

    NASA Astrophysics Data System (ADS)

    Fang, Ming; Chan, Chak K.; Yao, Xiaohong

    As the world gets ready to begin the second decade of the twenty-first century, global climate change has been recognized as a real threat to civilization as we know it. The rapid and successful economic growth of developing nations, particularly China and India, is contributing to climate change. The route to initial economic success in China followed that of the developed nations through the development of industries. Unfortunately, China's environmental protection efforts have not been the same as in developed countries because China is vastly different culturally, socially, economically and, especially, politically from developed nations. When China started to deal with environmental concerns in the late 1970s, it took advantage of the experiences of other countries in establishing environmental standards and regulations, but it did not have a model to follow when it came to implementing these standards and regulations because of the abovementioned differences. Economically, China is transitioning from an agricultural base into an industrial base; however, even now, 60% of the population remains farmers. China has been and still is heavily dependent upon coal for energy, resulting in serious atmospheric particulate pollution. While growing efforts have been expended on the environment, at this juncture of its economic development, China would be well served to revisit the traditional "develop first and clean up later" approach and to find a balance between development and protecting the environment. Against this backdrop, a reflective look of the effort to manage air quality from 1949-2008 (with an emphasis on the past 30 years) in China is presented in this paper. The environmental component of the 2008 Olympic Games is examined as a special example to illustrate the current measures being used to improve air quality in China.

  14. [Effect of flue gas conditions on NO oxidation process by DC corona radical shower].

    PubMed

    Wu, Zu-liang; Gao, Xiang; Li, Ming-bo; Zhang, Yuan-shang; Wu, Zu-cheng; Luo, Zhong-yang; Ni, Ming-jiang; Cen, Ke-fa

    2005-05-01

    Using an air-H2O DC corona radical shower system, the influences of reside time of flue gas in the reactor, velocity of flue gas and NO concentration on NO oxidation process were studied. The results show that the increasing velocity of flue gas can restrain corona development and the increasing NO concentration can make discharge more easy. The reside time of flue gas in the reactor has less effect on the NO oxidation. The NO oxidation rate increased only from 54.5% to 57.6% at 2 W input power when the reside time of flue gas in the reactor increased from 8.5 s to 34.2 s. However, the velocity of flue gas has important effect on the NO oxidation. At 1.7 W x h/m3 energy density, when the velocity of flue gas increased from 1.4 cm/s to 6.3 cm/s, the NO oxidation rate dropped from 60.0% to 38.6% and the energy yield also falled from 20.8 g/(kW x h) to 13.3 g/(kW x h). Under the certain flux of humid air, NO initial concentration has a best value, which was about 100 x 10(-6) in this experiment. PMID:16124460

  15. Transboundary air pollution in Asia: Model development and policy implications

    NASA Astrophysics Data System (ADS)

    Holloway, Tracey

    2001-12-01

    This work investigates transboundary air pollution in Asia through atmospheric modeling and public policy analysis. As an example of models actively shaping environmental policy, the Convention on Long-Range Transboundary Air Pollution in Europe (LRTAP) is selected as a case study. The LRTAP Convention is the only mulit- lateral air pollution agreement to date, and results from the RAINS integrated assessment model were heavily used to calculate nationally differentiated emission ceilings. Atmospheric chemistry and transport are included in RAINS through the use of transfer coefficients (or ``source-receptor relationships'') relating pollutant transfer among European nations. Following past work with ATMOS to simulate sulfur species in Asia, here ATMOS is developed to include odd-nitrogen. Fitting with the linear structure of ATMOS and the emphasis on computational efficiency, a simplified chemical scheme developed for use in the NOAA Geophysical Fluid Dynamics Laboratory Global Chemical Transport Model (GFDL GCTM) is adopted. The method solves for the interconversions between NOx, HNO3, and PAN based on five reaction rates stored in look-up tables. ATMOS is used to calculate source-receptor relationships for Asia. Significant exchange of NOy occurs among China, North and South Korea, and Japan. On an annual average basis, China contributes 18% to Japan's total nitrate deposition, 46% to North Korea, and 26% to South Korea. Nitrate deposition is an important component of acidification (along with sulfate deposition), contributing 30-50% to the acid burden over most of Japan, and more than 50% to acid deposition in southeast Asia, where biomass burning emits high levels of NOx. In evaluating the policy-relevance of results from the ATMOS model, four factors are taken into account: the uncertainty and limitations of ATMOS, the environmental concerns facing Asia, the current status of the scientific community in relation to regional air pollution in the region, and

  16. Development of solar driven absorption air conditioners and heat pumps

    NASA Astrophysics Data System (ADS)

    Dao, K.; Wahlig, M.; Wali, E.; Rasson, J.; Molishever, E.

    1980-03-01

    The development of absorption refrigeration systems for solar active heating and cooling applications is discussed. The approaches investigated are those using air-cooled condenser-absorber and those leading to coefficient of performances (COP) that increase continuously with heat source temperature. This is primarily an experimental project, with the emphasis on designing, fabricating and testing absorption chillers in operating regimes that are particularly suited for solar energy applications. Its demonstrated that the conventional single-effect ammonia-water absorption cycle can be used (with minor modifications) for solar cooling.

  17. Recent developments on Air Liquide advanced technologies turbines

    NASA Astrophysics Data System (ADS)

    Delcayre, Franck; Gondrand, Cecile; Drevard, Luc; Durand, Fabien; Marot, Gerard

    2012-06-01

    Air Liquide Advanced Technologies has developed for more than 40 years turboexpanders mainly for hydrogen and helium liquefiers and refrigerators and has in total more than 600 references of cryogenic turbo-expanders and cold compressors. The latest developments are presented in this paper. The key motivation of these developments is to improve the efficiency of the machines, and also to widen the range of operation. New impellers have been designed for low and high powers, the operation range is now between 200W and 200kW. The thrust bearings have been characterized in order to maximize the load which can be withstood and to increase the turbo-expander cold power. Considering low power machines, 3D open wheels have been designed and machined in order to increase the adiabatic efficiencies. A new type of machine, a turbobooster for methane liquefaction has been designed, manufactured and tested at AL-AT test facility.

  18. Design, fabrication and acceptance testing of a zero gravity whole body shower

    NASA Technical Reports Server (NTRS)

    Schumacher, E. A.; Lenda, J. A.

    1974-01-01

    Recent research and development programs have established the ability of the zero gravity whole body shower to maintain a comfortable environment in which the crewman can safely cleanse and dry the body. The purpose of this program was to further advance the technology of whole body bathing and to demonstrate technological readiness including in-flight maintenance by component replacement for flight applications. Three task efforts of this program are discussed. Conceptual designs and system tradeoffs were accomplished in task 1. Task 2 involved the formulation of preliminary and final designs for the shower, while task 3 included the fabrication and test of the shower assembly. Particular attention is paid to the evaluation and correction of test anomalies during the final phase of the program.

  19. Electroweakino pair production at the LHC: NLO SUSY-QCD corrections and parton-shower effects

    NASA Astrophysics Data System (ADS)

    Baglio, Julien; Jäger, Barbara; Kesenheimer, Matthias

    2016-07-01

    We present a set of NLO SUSY-QCD calculations for the pair production of neutralinos and charginos at the LHC, and their matching to parton-shower programs in the framework of the POWHEG-BOX program package. The code we have developed provides a SUSY Les Houches Accord interface for setting supersymmetric input parameters. Decays of the neutralinos and charginos and parton-shower effects can be simulated with PYTHIA. To illustrate the capabilities of our program, we present phenomenological results for a representative SUSY parameter point. We find that NLO-QCD corrections increase the production rates for neutralinos and charginos significantly. The impact of parton-shower effects on distributions of the weakinos is small, but non-negligible for jet distributions.

  20. High performance interactive graphics for shower reconstruction in HPC, the DELPHI barrel electromagnetic calorimeter

    SciTech Connect

    Stanescu, C. )

    1990-08-01

    Complex software for shower reconstruction in DELPHI barrel electromagnetic calorimeter which deals, for each event, with great amounts of information, due to the high spatial resolution of this detector, needs powerful verification tools. An interactive graphics program, running on high performance graphics display system Whizzard 7555 from Megatek, was developed to display the logical steps in showers and their axes reconstruction. The program allows both operations on the image in real-time (rotation, translation and zoom) and the use of non-geometrical criteria to modify it (as the use of energy) thresholds for the representation of the elements that compound the showers (or of the associated lego plots). For this purpose graphics objects associated to user parameters were defined. Instancing and modelling features of the native graphics library were extensively used.

  1. ACID GAS REMOVAL CHARACTERISTICS OF CORONA RADICAL SHOWER SYSTEM FOR A TREATMENT OF STATIONARY ENGINE FLUE GAS

    EPA Science Inventory

    Acid gas removal experiments are carried out in large bench scale corona radical shower reactor. A simulated engine flue gas is air mixed with NO, SO2 and CH4. Optimums for acid gas removal rate have been conducted in terms of the ammonia to acid gas molar ratio, the applied volt...

  2. Updraft Model for Development of Autonomous Soaring Uninhabited Air Vehicles

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.

    2006-01-01

    Large birds and glider pilots commonly use updrafts caused by convection in the lower atmosphere to extend flight duration, increase cross-country speed, improve range, or simply to conserve energy. Uninhabited air vehicles may also have the ability to exploit updrafts to improve performance. An updraft model was developed at NASA Dryden Flight Research Center (Edwards, California) to investigate the use of convective lift for uninhabited air vehicles in desert regions. Balloon and surface measurements obtained at the National Oceanic and Atmospheric Administration Surface Radiation station (Desert Rock, Nevada) enabled the model development. The data were used to create a statistical representation of the convective velocity scale, w*, and the convective mixing-layer thickness, zi. These parameters were then used to determine updraft size, vertical velocity profile, spacing, and maximum height. This paper gives a complete description of the updraft model and its derivation. Computer code for running the model is also given in conjunction with a check case for model verification.

  3. Development of an Air Pneumatic Suspension System for Transtibial Prostheses

    PubMed Central

    Pirouzi, Gholamhossein; Osman, Noor Azuan Abu; Oshkour, Azim Ataollahi; Ali, Sadeeq; Gholizadeh, Hossein; Wan Abas, Wan A. B.

    2014-01-01

    The suspension system and socket fitting of artificial limbs have major roles and vital effects on the comfort, mobility, and satisfaction of amputees. This paper introduces a new pneumatic suspension system that overcomes the drawbacks of current suspension systems in donning and doffing, change in volume during daily activities, and pressure distribution in the socket-stump interface. An air pneumatic suspension system (APSS) for total-contact sockets was designed and developed. Pistoning and pressure distribution in the socket-stump interface were tested for the new APSS. More than 95% of the area between each prosthetic socket and liner was measured using a Tekscan F-Scan pressure measurement which has developed matrix-based pressure sensing systems. The variance in pressure around the stump was 8.76 kPa. APSS exhibits less pressure concentration around the stump, improved pressure distribution, easy donning and doffing, adjustability to remain fitted to the socket during daily activities, and more adaptability to the changes in stump volume. The volume changes were adjusted by utility of air pressure sensor. The vertical displacement point and reliability of suspension were assessed using a photographic method. The optimum pressure in every level of loading weight was 55 kPa, and the maximum displacement was 6 mm when 90 N of weight was loaded. PMID:25207872

  4. Association of Improved Air Quality with Lung Development in Children

    PubMed Central

    Gauderman, W. James; Urman, Robert; Avol, Edward; Berhane, Kiros; McConnell, Rob; Rappaport, Edward; Chang, Roger; Lurmann, Fred; Gilliland, Frank

    2015-01-01

    BACKGROUND Air-pollution levels have been trending downward progressively over the past several decades in southern California, as a result of the implementation of air quality– control policies. We assessed whether long-term reductions in pollution were associated with improvements in respiratory health among children. METHODS As part of the Children’s Health Study, we measured lung function annually in 2120 children from three separate cohorts corresponding to three separate calendar periods: 1994–1998, 1997–2001, and 2007–2011. Mean ages of the children within each cohort were 11 years at the beginning of the period and 15 years at the end. Linear-regression models were used to examine the relationship between declining pollution levels over time and lung-function development from 11 to 15 years of age, measured as the increases in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) during that period (referred to as 4-year growth in FEV1 and FVC). RESULTS Over the 13 years spanned by the three cohorts, improvements in 4-year growth of both FEV1 and FVC were associated with declining levels of nitrogen dioxide (P<0.001 for FEV1 and FVC) and of particulate matter with an aerodynamic diameter of less than 2.5 μm (P = 0.008 for FEV1 and P<0.001 for FVC) and less than 10 μm (P<0.001 for FEV1 and FVC). These associations persisted after adjustment for several potential confounders. Significant improvements in lung-function development were observed in both boys and girls and in children with asthma and children without asthma. The proportions of children with clinically low FEV1 (defined as <80% of the predicted value) at 15 years of age declined significantly, from 7.9% to 6.3% to 3.6% across the three periods, as the air quality improved (P = 0.001). CONCLUSIONS We found that long-term improvements in air quality were associated with statistically and clinically significant positive effects on lung-function growth in children

  5. Air Force Satellite Control Network and SDI development

    NASA Astrophysics Data System (ADS)

    Bleier, T.

    The Air Force Satellite Control Network (AFSCN) represents a military, worldwide network of control centers and remote tracking sites (RTS). A relatively large and growing constellation of DOD satellites is supported. The near term and long term plans for the AFSCN are discussed, taking into account also the impact of the Space Defense Initiative (SDI) on the AFSCN. It is pointed out that the SDI adds a new dimension to the support provided by the AFSCN to the DOD satellites, because some SDI scenarios being considered include many more satellite platforms, each containing multiple kinetic energy weapons. Space-ground link sites are discussed along with AFSCN control sites, and communication between RTS and control centers. Attention is given to changing roles and responsibilities, the Satellite Test Center (STC) as an excellent site for the R and D phase of SDI development, and an operational concept for a highly proliferated weapons platforms architecture, and goals of developing more survivable satellite systems.

  6. The Impact of the Developmental Training Model on Staff Development in Air Force Child Development Programs

    ERIC Educational Resources Information Center

    Bird, Candace Maria Edmonds

    2010-01-01

    In an effort to standardize training delivery and to individualize staff development based on observation and reflective practice, the Air Force implemented the Developmental Training Model (DTM) in its Child Development Programs. The goal of the Developmental Training Model is to enhance high quality programs through improvements in the training…

  7. 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.

  8. Recent meteor showers - models and observations

    NASA Astrophysics Data System (ADS)

    Koten, P.; Vaubaillon, J.

    2015-10-01

    A number of meteor shower outbursts and storms occurred in recent years starting with several Leonid storms around 2000 [1]. The methods of modeling meteoroid streams became better and more precise. An increasing number of observing systems enabled better coverage of such events. The observers provide modelers with an important feedback on precision of their models. Here we present comparison of several observational results with the model predictions.

  9. The midpoint between dipole and parton showers

    NASA Astrophysics Data System (ADS)

    Höche, Stefan; Prestel, Stefan

    2015-09-01

    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. We provide two independent, publicly available implementations for the two event generators P ythia and S herpa.

  10. 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.

  11. Cometary showers and unseen solar companions

    NASA Technical Reports Server (NTRS)

    Weissman, P. R.

    1984-01-01

    The possibility that an invisible solar companion passing through the Oort cloud every 28 Myr precipitates a sufficiently high rate of cometary collisions with the earth to account for periodic mass species extinctions recorded in the fossil record is discussed. A Monte Carlo simulation shows that any hypothesized 'death star' with a 28 Myr orbit would experience an average 10 percent change in period per orbit. Production of an 18-fold increase in cometary impacts would be associated with a 0.055 probability that a 10 km nucleus would hit the earth in a shower once every 510 Myr, longer than the proposed extinction periodicity. However, if the death star orbit has a 0.6 eccentricity and the Oort cloud is sufficiently densely populated, a 2 billion comet shower may be possible. A survey of large terrestrial impact craters indicates that 6-12 craters with diameters over 10 km originated in periodic showers. The extinctions in any case occur at 26 Myr periods and cannot be correlated with the 33 Myr period of recrossing the galactic plane, or with any other known phenomena.

  12. 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.

  13. Development of a Test Facility for Air Revitalization Technology Evaluation

    NASA Technical Reports Server (NTRS)

    Lu, Sao-Dung; Lin, Amy; Campbell, Melissa; Smith, Frederick; Curley, Su

    2007-01-01

    Development of new air revitalization system (ARS) technology can initially be performed in a subscale laboratory environment, but in order to advance the maturity level, the technology must be tested in an end-to-end integrated environment. The Air Revitalization Technology Evaluation Facility (ARTEF) at the NASA Johnson Space Center serves as a ground test bed for evaluating emerging ARS technologies in an environment representative of spacecraft atmospheres. At the center of the ARTEF is a hypobaric chamber which serves as a sealed atmospheric chamber for closed loop testing. A Human Metabolic Simulator (HMS) was custom-built to simulate the consumption of oxygen, and production of carbon dioxide, moisture and heat of up to eight persons. A multitude of gas analyzers and dew point sensors are used to monitor the chamber atmosphere upstream and downstream of a test article. A robust vacuum system is needed to simulate the vacuum of space. A reliable data acquisition and control system is required to connect all the subsystems together. This paper presents the capabilities of the integrated test facility and some of the issues encountered during the integration.

  14. Influence of air pollution on respiratory health during perinatal development.

    PubMed

    Pinkerton, Kent E; Joad, Jesse P

    2006-03-01

    The respiratory system is a highly ordered structure composed of over 40 cell types involved in a multitude of functions. Development of the lungs spans from embryogenesis to adult life, passing through several distinct stages of growth. 2. Oxidant gases, airborne particles and environmental tobacco smoke are common air pollutants that could have a significant impact on the lungs during both pre- and postnatal periods of life. Although the specific target cells for exposure to these pollutants are not clearly identified, these cells are likely to affect critical signals or mediators expressed during distinct stages of lung development. 3. Neonatal susceptibility to environmental pollutants may be caused by either direct or indirect hits on several cell types to influence cell differentiation, proliferation and/or maturation. Air pollutants may also alter the normal developmental pattern for metabolic, immune and neurological functions that are constantly changing during in utero and postnatal growth. 4. The sensitivity of neonatal cells to environmental insults is likely to be completely different from these same cell types found in the adult. Delivery of an environmental toxicant to the respiratory system is also dramatically different during the fetal compared with the postnatal period. Passage and interaction of environmental factors through other organ systems and the vasculature, as well as maternal influences, must be taken into consideration when evaluating the impact of an environmental toxicant during early life. 5. To understand the heath outcomes of exposure to a variety of environmental factors in the respiratory system of children requires careful consideration that lung development is a multistep process and cannot be based on studies in adults. PMID:16487273

  15. 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.

  16. Application of thermoluminescence for detection of cascade shower 1: Hardware and software of reader system

    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

    A reader system for the detection of cascade showers via luminescence induced by heating sensitive material (BaSO4:Eu) is developed. The reader system is composed of following six instruments: (1) heater, (2) light guide, (3) image intensifier, (4) CCD camera, (5) image processor, (6) microcomputer. The efficiency of these apparatuses and software application for image analysis is reported.

  17. Measurement-while-drilling (MWD) development for air drilling

    SciTech Connect

    Rubin, L.A.; Harrison, W.H.

    1992-01-01

    The objective of this program is to tool-harden and make commercially available an existing wireless MWD tool to reliably operate in an air, air-mist, or air-foam environment during Appalachian Basin oil and gas directional drilling operations in conjunction with downhole motors and/or (other) bottom-hole assemblies. The application of this technology is required for drilling high angle (holes) and horizontal well drilling in low-pressure, water sensitive, tight gas formations that require air, air-mist, and foam drilling fluids. The basic approach to accomplishing this objective was to modify GEC's existing electromagnetic (e-m) CABLELESS''{trademark} MWD tool to improve its reliability in air drilling by increasing its tolerance to higher vibration and shock levels (hardening). Another important aim of the program is to provide for continuing availability of the resultant tool for use on DOE-sponsored, and other, air-drilling programs.

  18. Measurement-while-drilling (MWD) development for air drilling

    SciTech Connect

    Rubin, L.A.; Harrison, W.H.

    1992-06-01

    The objective of this program is to tool-harden and make commercially available an existing wireless MWD tool to reliably operate in an air, air-mist, or air-foam environment during Appalachian Basin oil and gas directional drilling operations in conjunction with downhole motors and/or (other) bottom-hole assemblies. The application of this technology is required for drilling high angle (holes) and horizontal well drilling in low-pressure, water sensitive, tight gas formations that require air, air-mist, and foam drilling fluids. The basic approach to accomplishing this objective was to modify GEC`s existing electromagnetic (e-m) ``CABLELESS``{trademark} MWD tool to improve its reliability in air drilling by increasing its tolerance to higher vibration and shock levels (hardening). Another important aim of the program is to provide for continuing availability of the resultant tool for use on DOE-sponsored, and other, air-drilling programs.

  19. Measurement-while-drilling (MWD) development for air drilling

    SciTech Connect

    Harrison, W.H.; Rubin, L.A.

    1992-05-01

    The objective of this program is to tool-harden and make commercially available an existing wireless MWD tool to reliably operate in an air, air-mist, or air-foam environment during Appalachian Basin oil and gas directional drilling operations in conjunction with downhole motors and/or (other) bottom-hole assemblies. The application of this technology is required for drilling high angle (holes) and horizontal well drilling in low- pressure, water sensitive, tight gas formations that require air, air-mist, and foam drilling fluids. The basic approach to accomplishing this objective was to modify GEC`s existing electromagnetic (e-m) {open_quotes}Cableless{close_quotes} MWD tool to improve its reliability in air drilling by increasing its tolerance to higher vibration and shock levels (hardening). Another important aim of the program is to provide for continuing availability of the resultant tool for use on DOE-sponsored, and other, air-drilling programs.

  20. Development of hot gas filtration for air blown gasification plant

    SciTech Connect

    Cahill, P.; Dutton, M.; Tustin, M.; Rasmussen, G.; Sage, P.

    1995-12-31

    This paper describes some of the development work carried out on hot gas filtration for the Air Blown Gasification Cycle (ABGC). The ABGC comprises partial gasification of coal at elevated pressure with combustion of the fuel gas produced in a gas turbine. The residual carbon from gasification is burned in an atmospheric pressure circulating fluidized bed combustor raising steam to drive a steam turbine. A critical requirement in the ABGC is to ensure that the fuel gas is free of dust, in order to avoid damage to the gas turbine. Ceramic filter elements are the preferred technology for this clean-up. The required operating temperature is 400--600 C, based on optimizing efficiency and to allow use of other hot gas clean-up systems, for instance for sulfur polishing. A development program on hot gas filtration has been carried out at CTDD in order to ensure that this component of the cycle can be used with minimum risk. To date, over 2,000 h of operation at up to 600 C has been achieved on two pilot scale hot gas filters, each taking full flow of gas from air blown gasifiers. The filters have operated with high availability and there have been no incidents of breakage of filter elements. Information has been generated for effect of filtration velocity and temperature, cleaning gas requirements, changing dust and gas composition, and for design of critical components such as fast opening valves, venturi ejectors and sealing mechanisms. The effect of different operating conditions on filter element strength has been evaluated for a range of filter elements.

  1. An ionization chamber shower detector for the LHC Luminosity Monitor

    SciTech Connect

    Speziali, V.; Beche, J.F.; Burks, M.T.; Datte, P.S.; Haguenauer, M.; manfredi, P.F.; Millaud, J.E.; Placidi, M.; Ratti, L.; Re, V.; Riot, V.J.; Schmickler, H.; Turner, W.C.

    2000-10-01

    The front IR quadrupole absorbers (TAS) and the IR neutral particle absorbers (TAN) in the high luminosity insertions of the Large Hadron Collider (LHC) each absorb approximately 1.8 TeV of forward collision products on average per pp interaction (~;;235W at design luminosity 1034cm-2s-1). This secondary particle flux can be exploited to provide a useful storage ring operations tool for optimization of luminosity. A novel segmented, multi-gap, pressurized gas ionization chamber is being developed for sampling the energy deposited near the maxima of the hadronic/ electromagnetic showers in these absorbers. The system design choices have been strongly influenced by optimization of signal to noise ratio and by the very high radiation environment. The ionization chambers are instrumented with low noise, fast, pulse shaping electronics to be capable of resolving individual bunch crossings at 40 MHz. Data on each bunch are to be separately accumulated over multiple bunch crossings until the desired statistical accuracy is obtained. At design luminosity approximately 2x103 bunch crossings will suffice for a 1percent luminosity measurement. In this paper we report the first experimental results of the ionization chamber and analog electronics. Single 450GeV protons from the SPS at CERN are used to simulate the hadronic/electromagnetic showers produced by the forward collision products from the interaction regions of the LHC.

  2. The I.A.U. meteor shower nomenclature rules

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter

    2006-10-01

    The International Astronomical Union at its 2006 General Assembly in Prague has adopted a set of rules for meteor shower nomenclature, a working list with designated names (with IAU numbers and three-letter codes), and established a Task Group for Meteor Shower Nomenclature in Commission 22 (Meteors and Interplanetary Dust) to help define which meteor showers exist from well defined groups of meteoroids from a single parent body.

  3. Development of a Low Pressure, Air Atomized Oil Burner with High Atomizer Air Flow: Progress Report FY 1997

    SciTech Connect

    Butcher, T.A.

    1998-01-01

    This report describes technical advances made to the concept of a low pressure, air atomized oil burner for home heating applications. Currently all oil burners on the market are of the pressure atomized, retention head type. These burners have a lower firing rate limit of about 0.5 gallons per hour of oil, due to reliability problems related to small flow passage sizes. High pressure air atomized burners have been shown to be one route to avoid this problem but air compressor cost and reliability have practically eliminated this approach. With the low pressure air atomized burner the air required for atomization can be provided by a fan at 5-8 inches of water pressure. A burner using this concept, termed the Fan-Atomized Burner or ''FAB'' has been developed and is currently being commercialized. In the head of the FAB, the combustion air is divided into three parts, much like a conventional retention head burner. This report describes development work on a new concept in which 100% of the air from the fan goes through the atomizer. The primary advantage of this approach is a great simplification of the head design. A nozzle specifically sized for this concept was built and is described in the report. Basic flow pressure tests, cold air velocity profiles, and atomization performance have been measured. A burner head/flame tube has been developed which promotes a toroidal recirculation zone near the nozzle for flame stability. The burner head has been tested in several furnace and boiler applications over the firing rate range 0.2 to 0.28 gallons per hour. In all cases the burner can operate with very low excess air levels (under 10%) without producing smoke. Flue gas NO{sub x} concentration varied from 42 to 62 ppm at 3% O{sub 2}. The concept is seen as having significant potential and planned development efforts are discussed.

  4. Electromagnetic Shower Reconstruction for theSilicon Detector

    SciTech Connect

    Meyer, N.

    2005-12-08

    This report presents a two-pass reconstruction algorithm for electromagnetic showers, based on studies with simulated photons in the highly segmented Silicon Tungsten calorimeter of the Silicon Detector concept for the International Linear Collider. It is shown that the initial reconstruction and identification of the dense shower cores allows shower separation down to 3 cm distance between two photons on the calorimeter surface. First results are shown for the subsequent collection of unassociated hits around the shower cores necessary to reconstruct complete energy deposits by individual particles.

  5. DEVELOPMENT AND ANALYSIS OF AIR QUALITY MODELING SIMULATIONS FOR HAZARDOUS AIR POLLUTANTS

    EPA Science Inventory

    The concentrations of five hazardous air pollutants were simulated using the Community Multi Scale Air Quality (CMAQ) modeling system. Annual simulations were performed over the continental United States for the entire year of 2001 to support human exposure estimates. Results a...

  6. Measurement of the proton-air inelastic cross section at {radical}(s){approx_equal}2 TeV from the EAS-TOP experiment

    SciTech Connect

    Aglietta, M.; Castellina, A.; Fulgione, W.; Mannocchi, G.; Morello, C.; Trinchero, G. C.; Vallania, P.; Vernetto, S.; Alessandro, B.; Antonioli, P.; Arneodo, F.; Bergamasco, L.; Bertaina, M.; Chiavassa, A.; Galeotti, P.; Navarra, G.; Saavedra, O.; Vigorito, C.; Cantoni, E.; D'Ettorre Piazzoli, B.

    2009-02-01

    The proton-air inelastic cross section ({sigma}{sub p-air}{sup inel}) is measured at {radical}(s){approx_equal}2 TeV at the EAS-TOP extensive air shower experiment by studying the absorption length of cosmic ray proton primaries cascades reaching the maximum development at the observation level. Primary energies, in the region E{sub 0}=(1.5 divide 2.5){center_dot}10{sup 15} eV, are selected through the EAS muon number (N{sub {mu}}), and proton originated cascades at maximum development are selected by means of the shower size (N{sub e}). The observed absorption length ({lambda}{sub obs}) is a convolution of the proton-air interaction length ({lambda}{sub p-air}) and of the shower and detector fluctuations. The conversion factor k={lambda}{sub obs}/{lambda}{sub int} is obtained by means of simulations performed with the CORSIKA code and the QGSJET II and SIBYLL interaction models. The obtained value of the p-air inelastic cross section at {radical}(s){approx_equal}2 TeV is {sigma}{sub p-air}{sup inel}=338{+-}21(stat){+-}19(syst)-28(syst) mb. The statistical and systematic uncertainties, as well as the relationships with the pp (pp) total cross section measurements are discussed.

  7. Muons emitted from showers produced by Geminga-pulsar gamma rays.

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, D. P.

    1997-12-01

    The derivation of integral energy spectrum of muons produced by the interactions in gamma-ray showers induced by energetic photons from the Geminga pulsar has been made. The conventional analytical procedure of Drees et al. (1988) has been adopted for muon-number calculations from photoproduced air showers. The FNAL data on πp→π±X inclusive reactions, and the HERA ep collider results have been used for the evaluation of the hadronic energy moments and the photonuclear cross-sections, respectively. The integral number of muons was derived for Zππ = 0.499, σγN = 0.119 mb and σπA = 198 mb. It exhibits a drastic decrease with energy.

  8. Development and Application of a Next Generation Air Sensor Network for the Hong Kong Marathon 2015 Air Quality Monitoring

    PubMed Central

    Sun, Li; Wong, Ka Chun; Wei, Peng; Ye, Sheng; Huang, Hao; Yang, Fenhuan; Westerdahl, Dane; Louie, Peter K.K.; Luk, Connie W.Y.; Ning, Zhi

    2016-01-01

    This study presents the development and evaluation of a next generation air monitoring system with both laboratory and field tests. A multi-parameter algorithm was used to correct for the impact of environmental conditions on the electrochemical sensors for carbon monoxide (CO) and nitrogen dioxide (NO2) pollutants. The field evaluation in an urban roadside environment in comparison to designated monitors showed good agreement with measurement error within 5% of the pollutant concentrations. Multiple sets of the developed system were then deployed in the Hong Kong Marathon 2015 forming a sensor-based network along the marathon route. Real-time air pollution concentration data were wirelessly transmitted and the Air Quality Health Index (AQHI) for the Green Marathon was calculated, which were broadcast to the public on an hourly basis. The route-specific sensor network showed somewhat different pollutant patterns than routine air monitoring, indicating the immediate impact of traffic control during the marathon on the roadside air quality. The study is one of the first applications of a next generation sensor network in international sport events, and it demonstrated the usefulness of the emerging sensor-based air monitoring technology in rapid network deployment to supplement existing air monitoring. PMID:26861336

  9. Development and Application of a Next Generation Air Sensor Network for the Hong Kong Marathon 2015 Air Quality Monitoring.

    PubMed

    Sun, Li; Wong, Ka Chun; Wei, Peng; Ye, Sheng; Huang, Hao; Yang, Fenhuan; Westerdahl, Dane; Louie, Peter K K; Luk, Connie W Y; Ning, Zhi

    2016-01-01

    This study presents the development and evaluation of a next generation air monitoring system with both laboratory and field tests. A multi-parameter algorithm was used to correct for the impact of environmental conditions on the electrochemical sensors for carbon monoxide (CO) and nitrogen dioxide (NO2) pollutants. The field evaluation in an urban roadside environment in comparison to designated monitors showed good agreement with measurement error within 5% of the pollutant concentrations. Multiple sets of the developed system were then deployed in the Hong Kong Marathon 2015 forming a sensor-based network along the marathon route. Real-time air pollution concentration data were wirelessly transmitted and the Air Quality Health Index (AQHI) for the Green Marathon was calculated, which were broadcast to the public on an hourly basis. The route-specific sensor network showed somewhat different pollutant patterns than routine air monitoring, indicating the immediate impact of traffic control during the marathon on the roadside air quality. The study is one of the first applications of a next generation sensor network in international sport events, and it demonstrated the usefulness of the emerging sensor-based air monitoring technology in rapid network deployment to supplement existing air monitoring. PMID:26861336

  10. Developments in Airborne Oceanography and Air-Sea Interaction

    NASA Astrophysics Data System (ADS)

    Melville, W. K.

    2014-12-01

    One of the earliest ocean-related flights was that of Amundsen to be first across the North Pole and Arctic from Svalbard to Alaska in the airship Norge in 1926. Twenty five years later Cox & Munk flew a B-17G "Flying Fortress" bomber over Hawaiian waters measuring sea surface slope statistics from photographs of sun glitter and wind speed from a yacht. The value of Cox & Munk's "airborne oceanography" became apparent another twenty five years later with the short-lived Seasat microwave remote-sensing mission, since interpretation of the Seasat data in geophysical variables required scattering theories that relied on their data. The universal acceptance of remote sensing in oceanography began in 1992 with the launch of, and successful analysis of sea surface height data from, the Topex/Poseidon radar altimeter. With that and the development of more realistic coupled atmosphere-ocean models it became apparent that our understanding of weather and climate variability in both the atmosphere and the ocean depends crucially on our ability to measure processes in boundary layers spanning the interface. Ten years ago UNOLS formed the Scientific Committee for Oceanographic Aircraft Research (SCOAR) "...to improve access to research aircraft facilities for ocean sciences"; an attempt to make access to aircraft as easy as access to research vessels. SCOAR emphasized then that "Aircraft are ideal for both fast-response investigations and routine, long-term measurements, and they naturally combine atmospheric measurements with oceanographic measurements on similar temporal and spatial scales." Since then developments in GPS positioning and miniaturization have made scientific measurements possible from smaller and smaller platforms, including the transition from manned to unmanned aerial vehicles (UAVs). Furthermore, ship-launched and recovered UAVs have demonstrated how they can enhance the capabilities and reach of the research vessels, "projecting" research and science

  11. Perception of Air Pollution in a Developing Country

    ERIC Educational Resources Information Center

    Bladen, W. A.; Karan, P. P.

    1976-01-01

    This study analyzed the perception of air pollution of people living in an industrial area of India. Although air pollution was perceived as a problem it was ranked less important than socio-economic problems. Differences in perception existed among the various cultural groups and among the residential zones. (MR)

  12. 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.

  13. 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.

  14. Highly granular hadron calorimeter: software compensation and shower decomposition

    NASA Astrophysics Data System (ADS)

    Chadeeva, M.; CALICE Collaboration

    2016-02-01

    The highly granular analogue hadron calorimeter was developed and constructed by the CALICE collaboration. The active layers of the calorimeter are assembled from scintillator tiles with individual readout by silicon photomultipliers and are interleaved with absorber plates. The response and resolution of the calorimeter equipped with steel absorber was intensively tested in single particle beams. The application of software compensation techniques developed for the scintillator-steel prototype allows for reduction of the stochastic term of the single particle resolution from 58%/ √E/GeV to 45%/ √E/GeV. The detailed study and decomposition of the longitudinal and radial profiles of hadron-induced showers in the energy range from 10 to 80 GeV are presented and compared to GEANT4 simulations.

  15. Milagro: A low energy threshold extensive air shower array

    NASA Astrophysics Data System (ADS)

    Sinnis, Gus

    1995-07-01

    Observations of gamma-ray bursts, active galactic nuclei, and radio pulsars by CGRO have revolutionized our view of the cosmos. Sources may pop into existence for a few milliseconds never to appear again and galaxies can change their luminosity by an order of magnitude within a few days. In addition to these space-based measurements, there have been at least 2 sources detected at even higher energies, ~1 TeV, using earth-bound detectors. To date, ground-based detectors of high-energy gamma rays with energy thresholds low enough to make credible detections have all had narrow fields of view and low duty factors. While these detectors are well suited to perform detailed studies of selected sources, they can not perform surveys of the entire sky with adequate sensitivity in a reasonable amount of time. We have designed a new type of ground-based gamma-ray detector with a low energy threshold, ~250 GeV, large aperture (~1 sr), and a duty factor greater than 90%-Milagro.

  16. On the theory of fluctuations in extensive air showers

    SciTech Connect

    Lagutin, A.A.; Uchai-brevekin, V.V.; Chernyaev, G.V.

    1987-03-01

    A method is presented for calculating the fluctuations of various components of EAS using the distributions in the eventual characteristics (the inelasticity coefficients and multiplicities). The inverse (conjugate) equations for the covariational matrix of EAS are derived and analyzed. Some results of numerical calculations of fluctuations of EAS characteristics using the quark--gluon string model of hadron--nucleus interactions are presented.

  17. Gamma-ray Astronomy with Air Shower Arrays

    NASA Astrophysics Data System (ADS)

    Ona-Wilhelmi, Emma

    2016-07-01

    Gamma-ray astronomy has experience a revolution in the last decade, becoming a truly domain in astrophysics. Present arrays of Cherenkov telescope have sensitivities of more than 100 times the pioneering ones, enlarging the working energy range from a few tens of GeV to tens of TeV. Thanks to these improvements, the number of gamma-ray sources, Galactic and extragalactic, exceeds more than 175, opening a new window on the non-thermal Universe. We will review the most relevant results on the field, and will give a general status of the current and future Gamma-ray instruments.

  18. 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.

  19. Estimating risk during showering exposure to VOCs of workers in a metal-degreasing facility.

    PubMed

    Franco, Amaya; Costoya, Miguel Angel; Roca, Enrique

    2007-04-01

    The incremental risk of workers in a metal-degreasing facility exposed to volatile organic compounds (VOCs) present in the water supply during showering was estimated. A probabilistic and worst-case approach using specific-site concentration data and a generalized multipathway exposure model was applied. Estimates of hazard index and lifetime cancer risk were analyzed for each chemical and each route of exposure (inhalation and dermal absorption). The results showed that dermal exposure to trichloroethylene (TCE) and tetrachloroethylene (perchloroethylene, PCE) represented the main contribution to total risk. Although the inhalation route did not produce significant exposure, it was mainly influenced by the liquid flow rate of the shower. Lower values of this parameter during showering resulted in a significant reduction of both carcinogenic and noncarcinogenic risk, while decreasing water temperature produced a minimal effect on exposure by this pathway. The results obtained in the present study indicated that significant exposures of workers may be produced during showering in metal degreasing installations where releases to water of VOCs occur. A sensitivity analysis was developed for investigating the effect of scenario parameters on exposure. Although site-specific data were employed, the exposure of workers was assessed in a model scenario and thus the quantification of risk is associated with uncertainty. Considering that occupational exposure to organic solvents of workers in metal-degreasing facilities may also be significant, risk assessment must be included in the planning of this kind of industrial installation. PMID:17365617

  20. The structure of the shower disk observed at Mt. Norikura

    NASA Technical Reports Server (NTRS)

    Ohmori, N.; Horiki, T.; Sasaki, H.; Nishioka, A.; Kusumose, M.; Nakatsuka, T.; Hatano, Y.

    1985-01-01

    The structure of the EAS shower disk, the arrival time distribution of charged particles at the core of the small or middle size shower, is measured at Mt. Norikura in Japan. Four fast scintillation counters with an area of 0.25 sq m and a fast trigger system are added to the Mt. Norikura EAS array for the study.

  1. Romanian Observational Campaign on Summer Meteor Showers in 2000

    NASA Astrophysics Data System (ADS)

    Berinde, S.; Grigore, V.

    2001-01-01

    In this paper we summarize the most important results of a summer observational campaign dedicated to the observation of the entire spectrum of active meteor showers on this period. Our results are enriched by the determination of two possible new radiants in Cygnus, not related to any other known meteor shower.

  2. 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.

  3. 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.

  4. Showering cosmogenic muons in a large liquid scintillator

    NASA Astrophysics Data System (ADS)

    Grassi, Marco; Evslin, Jarah; Ciuffoli, Emilio; Zhang, Xinmin

    2014-09-01

    We present the results of FLUKA simulations of the propagation of cosmogenic muons in a 20 kton spherical liquid scintillator detector underneath 700 to 900 meters of rock. A showering muon is one which deposits at least 3 GeV in the detector in addition to ionization energy. We find that 20 percent of muons are showering and a further 11 percent of muon events are muon bundles, of which more than one muon enters the detector. In this range the showering and bundle fractions are robust against changes in the depth and topography, thus the total shower and bundle rate for a given experiment can be obtained by combining our results with an estimate for the total muon flux. One consequence is that a straightforward adaptation of the full detector showering muon cuts used by KamLAND to JUNO or RENO 50 would yield a nearly vanishing detector efficiency.

  5. 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.

  6. DEVELOPMENT OF CRITERIA FOR SITING AIR MONITORING STATIONS

    EPA Science Inventory

    This paper reviews relevant research findings for the purpose of establishing a set of uniform national criteria for designating locations of air monitoring stations. Data first are presented showing the difficulty, in the absence of uniform criteria, of interpreting measurements...

  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. Air-Breathing Launch Vehicle Technology Being Developed

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.

    2003-01-01

    Of the technical factors that would contribute to lowering the cost of space access, reusability has high potential. The primary objective of the GTX program is to determine whether or not air-breathing propulsion can enable reusable single-stage-to-orbit (SSTO) operations. The approach is based on maturation of a reference vehicle design with focus on the integration and flight-weight construction of its air-breathing rocket-based combined-cycle (RBCC) propulsion system.

  9. Development of a solar-powered residential air conditioner

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The initial objective of the program was the optimization (in terms of cost and performance) of a Rankine cycle mechanical refrigeration system which utilizes thermal energy from a flat solar collector for air conditioning residential buildings. However, feasibility investigations of the adsorption process revealed that a dessicant-type air conditioner offers many significant advantages. As a result, limited efforts were expended toward the optimization of such a system.

  10. Global partnerships: A collaborative effort to improve air quality in developing countries

    SciTech Connect

    Calkins, D.L.

    1998-12-31

    Since 1970, the World Health Organization (WHO) and the United Nations Environmental Programme (UNEP) has coordinated the operation of a worldwide air pollution monitoring program, formerly known as the Global Environmental Monitoring System/Air (GEMS/Air) and now a part of the WHO`s Air Management Information Systems (AMIS). GEMS/Air has operated more than 250 ambient air monitoring stations in more than 50 nations since 1970. The focus has been on improving air quality data and emission inventories in developing countries, ultimately leading to setting appropriate health standards and developing national plans for air quality improvements. As funding is often limited in these countries, WHO has established the twinning concept of matching air pollution agencies in Europe and the United States with those developing countries needing assistance. The notion is for a donor agency to provide used air monitors and technical assistance to a sister city or country. Such monitors, though not necessarily state-of-the-art in the United States but clearly operational, would provide improved monitoring data in many developing countries, thus leading to a better understanding of the worldwide impacts of air pollution on public health and natural resources. This paper will describe the process, participation, and the ultimate goals of developing a Global Air Quality Partnership among the participants. It addresses worldwide air quality problems, especially in the megacities of the world. Finally, it discusses problems encountered in providing technical assistance to developing countries and how international organizations, such as A and WMA, might help improved air quality management in these areas.

  11. Necessity and Effect of Combating Legionella pneumophila in Municipal Shower Systems

    PubMed Central

    Wiik, Ragnhild; Krøvel, Anne Vatland

    2014-01-01

    The objective was to obtain research-based, holistic knowledge about necessity and effect of practiced measures against L. pneumophila in municipal shower systems in Stavanger, Norway. The effects of hot water treatment and membrane-filtering were investigated and compared to no intervention at all. The studies were done under real-world conditions. Additionally, a surveillance pilot study of municipal showers in Stavanger was performed. The validity of high total plate count (TPC) as an indication of L. pneumophila was evaluated. A simplified method, named “dripping method”, for detection and quantification of L. pneumophila was developed. The sensitivity of the dripping method is 5 colony-forming units of L. pneumophila/ml. The transference of L. pneumophila from shower water to aerosols was studied. Interviews and observational studies among the stakeholders were done in order to identify patterns of communication and behavior in a Legionella risk perspective. No substantial effects of the measures against L. pneumophila were demonstrated, except for a distally placed membrane filter. No significant positive correlation between TPC and L. pneumophila concentrations were found. L. pneumophila serogroup 2–14 was demonstrated in 21% of the 29 buildings tested in the surveillance pilot. Relatively few cells of L. pneumophila were transferred from shower water to aerosols. Anxiety appeared as the major driving force in the risk governance of Legionella. In conclusion, the risk of acquiring Legionnaires' disease from municipal shower systems is evaluated as low and uncertain. By eliminating ineffective approaches, targeted Legionella risk governance can be practiced. Risk management by surveillance is evaluated as appropriate. PMID:25490721

  12. Study of muons near shower cores at sea level using the E594 neutrino detector

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    The E594 neutrino detector has been used to study the lateral distribution of muons of energy 3 GeV near shower cores. The detector consists of a 340 ton fine grain calorimeter with 400,000 cells of flash chamber and dimensions of 3.7 m x 20 m x 3.7 m (height). The average density in the calorimeter is 1.4 gm/sq cm, and the average Z is 21. The detector was triggered by four 0.6 sq m scintillators placed immediately on the top of the calorimeter. The trigger required at least two of these four counters. The accompanying extensive air showers (EAS) was sampled by 14 scintillation counters located up to 15 m from the calorimeter. Several off line cuts have been applied to the data. Demanding five particles in at least two of the trigger detectors, a total of 20 particles in all of them together, and an arrival angle for the shower 450 deg reduced the data sample to 11053 events. Of these in 4869 cases, a computer algorithm found at least three muons in the calorimeter.

  13. Graphical User Interface Development for Representing Air Flow Patterns

    NASA Technical Reports Server (NTRS)

    Chaudhary, Nilika

    2004-01-01

    In the Turbine Branch, scientists carry out experimental and computational work to advance the efficiency and diminish the noise production of jet engine turbines. One way to do this is by decreasing the heat that the turbine blades receive. Most of the experimental work is carried out by taking a single turbine blade and analyzing the air flow patterns around it, because this data indicates the sections of the turbine blade that are getting too hot. Since the cost of doing turbine blade air flow experiments is very high, researchers try to do computational work that fits the experimental data. The goal of computational fluid dynamics is for scientists to find a numerical way to predict the complex flow patterns around different turbine blades without physically having to perform tests or costly experiments. When visualizing flow patterns, scientists need a way to represent the flow conditions around a turbine blade. A researcher will assign specific zones that surround the turbine blade. In a two-dimensional view, the zones are usually quadrilaterals. The next step is to assign boundary conditions which define how the flow enters or exits one side of a zone. way of setting up computational zones and grids, visualizing flow patterns, and storing all the flow conditions in a file on the computer for future computation. Such a program is necessary because the only method for creating flow pattern graphs is by hand, which is tedious and time-consuming. By using a computer program to create the zones and grids, the graph would be faster to make and easier to edit. Basically, the user would run a program that is an editable graph. The user could click and drag with the mouse to form various zones and grids, then edit the locations of these grids, add flow and boundary conditions, and finally save the graph for future use and analysis. My goal this summer is to create a graphical user interface (GUI) that incorporates all of these elements. I am writing the program in

  14. Improved fireman's compressed air breathing system pressure vessel development program

    NASA Technical Reports Server (NTRS)

    King, H. A.; Morris, E. E.

    1973-01-01

    Prototype high pressure glass filament-wound, aluminum-lined pressurant vessels suitable for use in a fireman's compressed air breathing system were designed, fabricated, and acceptance tested in order to demonstrate the feasibility of producing such high performance, lightweight units. The 4000 psi tanks have a 60 standard cubic foot (SCF) air capacity, and have a 6.5 inch diamter, 19 inch length, 415 inch volume, weigh 13 pounds when empty, and contain 33 percent more air than the current 45 SCF (2250 psi) steel units. The current steel 60 SCF (3000 psi) tanks weigh approximately twice as much as the prototype when empty, and are 2 inches, or 10 percent shorter. The prototype units also have non-rusting aluminum interiors, which removes the hazard of corrosion, the need for internal coatings, and the possibility of rust particles clogging the breathing system.

  15. 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. PMID:26311585

  16. The effect of shower/bath frequency on the health and operational effectiveness of soldiers in a field setting: Recommendation of showering frequencies for reducing performance-degrading nonsystemic microbial skin infections

    SciTech Connect

    Hall, L.C.; Daniels, J.I.; Aly, R.; Maibach, H.I.; Schaub, S.A.; Becker, L.E.

    1991-09-30

    Historically, military personnel deployed in the field, particularly in hot, humid environments, have suffered disabling microbial infections of the skin severe enough to contribute to significant reductions in combat-troop strength. Currently, the US Army makes facilities available to field personnel for showering on a weekly basis to prevent infestations of the body louse and the subsequent spread of louse-borne disease. However, a weekly showering frequency has never been evaluated for its efficacy in preventing microbial infections of the skin -- a significant cause of man-days lost from combat in modern-day military conflicts. Consequently, field showers may be more important for maintaining combat effectiveness of military personnel than previously thought; however, providing such facilities requires tremendous logistical support. Therefore, we developed shower frequencies for troops in field environments that should minimize or prevent microbial skin infections. According to our calculations, the optimum showering frequency can range from as often as four times per day to as little as once every seven days, depending on skin integrity, environmental conditions, and cleansing agent. We also reviewed the scientific and regulatory information concerning the efficacy and safety of skin-cleansing products; the antimicrobial and antiseptic compounds, triclocarban and chlorhexidine, may be the most suitable for routine use by US military personnel.

  17. Development of Air-cooled Engines with Blower Cooling

    NASA Technical Reports Server (NTRS)

    Lohner, Kurt

    1933-01-01

    With the aid of a heating device, the heat transfer to cylinders with conical fins of various forms is determined both for shrouded and exposed cylinders. Simultaneously the pressure drop for overcoming the resistance to the motion of air between the fins of the enclosed cylinder is measured. Thus the relations between the heat transfer and the energy required for cooling are discovered. The investigations show that the heat transfer in a conducted air flow is much greater than in a free current and that further improvement, as compared with free exposure, is possible through narrower spaces between the fins.

  18. Recent advances in the development of Li-air batteries

    NASA Astrophysics Data System (ADS)

    Capsoni, Doretta; Bini, Marcella; Ferrari, Stefania; Quartarone, Eliana; Mustarelli, Piercarlo

    2012-12-01

    The global energy demand calls for more efficient storage systems. In this review, the state of the art of Li/air and Li/O2 batteries is discussed with particular attention on the more recent findings regarding all the battery compartments. Both aqueous and non-aqueous systems are considered, and the most critical issues for better battery design are addressed. Whereas the predicted charge/discharge values for these devices do justify the intense research efforts performed nowadays, great problems are still present which must be overcome in order to make Li/air and Li/O2 a reality for future large-scale applications.

  19. Electric air filtration: theory, laboratory studies, hardware development, and field evaluations

    SciTech Connect

    Bergman, W.; Biermann, A.; Kuhl, W.; Lum, B.; Bogdanoff, A.; Hebard, H.; Hall, M.; Banks, D.; Mazumder, M.; Johnson, J.

    1983-09-01

    We summarize the results of a seven-year research project for the US Department of Energy (DOE) to develop electric air filters that extend the service life of high-efficiency particulate air (HEPA) filters used in the nuclear industry. This project was unique to Lawrence Livermore National Laboratory (LLNL), and it entailed comprehensive theory, laboratory studies, and hardware development. We present our work in three major areas: (1) theory of and instrumentation for filter test methods, (2) theoretical and laboratory studies of electric air filters, and (3) development and evaluation of eight experimental electric air filters.

  20. METHODS DEVELOPMENT FOR ASSESSING AIR POLLUTION CONTROL BENEFITS. VOLUME I. EXPERIMENTS IN THE ECONOMICS OF AIR POLLUTION EPIDEMIOLOGY

    EPA Science Inventory

    The volume employs the analytical and empirical methods of economics to develop hypotheses on disease etiologies and to value labor productivity and consumer losses due to air pollution-induced mortality and morbidity. In the mortality work, 1970 city-wide mortality rates for maj...