Studies of the Highest Energy Cosmic Ray Air Showers with the Pierre Auger Observatory Hybrid Dectector PDF Download

Author: Bei Cai
Publisher:
ISBN:
Category :
Languages : en
Pages : 346

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Author: Alessio Gorgi
Publisher:
ISBN:
Category :
Languages : en
Pages : 119

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The Pierre Auger Observatory aims to study the ultra high energy cosmic rays with energies above 1 EeV. To get an accurate measurement of the characteristic of the extensive air showers that the cosmic rays generate in the atmosphere, the Observatory uses a hybrid technique. In this work we have studied the detector performance, including trigger and hardware efficiencies. We have optimized the event selection and estimated the efficiency of the detector acceptance. Uncertainties for event reconstruction were evaluated and propagated to the measured energy spectrum. We have shown that some stations that are not courrently considered part of the event can be included in the event selection procedure. We have studied the effect of loosing the signal of one of the three photomultipliers due to some failure, or the effect of the saturation of the ADC channels or of the photomultiplier to the reconstruction accuracy. The reconstruction uncertainty was also studied in case of ``normal'' events using a method based on fluctuations, to cross-check the results obtained using the fit accuracies. An evaluation of the trigger efficiency was also performed in case one of the three photomultipliers is missing. We have shown that the problems related to the instrumental apparatus only reduce the efficiency where it is not already 100\% and in most of the cases the reconstruction uncertainties are only slightly affected. Furthermore this work gives the first indication that the reconstruction uncertainties of the surface detector data do not change the index of the power law of the measured cosmic rays spectrum.

Author:
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Category :
Languages : en
Pages : 15

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The Pierre Auger project is a broadly based international effort to make a detailed study of cosmic rays at the highest energies. Two air shower detectors are proposed, one to be placed in the Northern Hemisphere and one in the Southern Hemisphere. Each installation will consist of an array of 1600 particle detectors spread over 3000 km2 with a solid angle acceptance of 2 sr for cosmic ray air showers. Eah installation will also have an atmospheric fluorescence detector viewing the volume above the surface array. These two air shower detector techniques working together form a powerful instrument for the proposed research. The objectives of the Pierre Auger project are to measure the arrival direction, energy, and mass composition of 60 events per year above an energy of 102° eV and 6000 events per year above 1019 eV. A collaboration is now being formed with the goal of having the Pierre Auger observatory in operation by 2001.

Author: M. V. S. Rao
Publisher: World Scientific
ISBN: 9789810228880
Category : Science
Languages : en
Pages : 372

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Ultrahigh energy cosmic rays carry information about their sources and the intervening medium apart from providing a beam of particles for studying certain features of high energy interactions currently inaccessible at man-made accelerators. They can at present be studied only via the extensive air showers (EAS's) they generate while passing through the Earth's atmosphere, since their fluxes are too low for the experiments of limited capability flown in balloons and satellites. The EAS is generated by a series of interactions of the primary cosmic ray and its progeny with the atmospheric nuclei. The exponential nature of the atmosphere spreads the air showers laterally over several hundreds of meters, thus enabling ground-based arrays of relatively inexpensive detectors to record and study them.This book describes the EAS phenomenology, the detectors and techniques used, and the latest results on the energy spectrum and composition of the primaries of EAS's and the results on high energy interactions obtained from EAS studies. It also describes the new TeV and PeV gamma ray astronomy (which has been developing over the past decade) and the newly emerging neutrino astronomy, which are related to the origin of cosmic rays.This book serves as an introduction as well as a reference for researchers in the field.

Author:
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Category :
Languages : en
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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.

Author: Inés Valiño Rielo
Publisher: Univ Santiago de Compostela
ISBN:
Category :
Languages : en
Pages : 238

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Author: I.H. Cairns
Publisher: Springer Science & Business Media
ISBN: 9400710690
Category : Science
Languages : en
Pages : 535

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Advances in Space Environment Research - Volume I contains the proceedings of two international workshops, the World Space Environment Forum (WSEF2002) and the High Performance Computing in Space Environment Research (HPC2002), organized by the World Institute for Space Environment Research (WISER) from 22 July to 2 August 2002 in Adelaide, Australia. The articles in this volume review the state-of-the-art of the theoretical, computational and observational studies of the physical processes of Sun-Earth connections and Space Environment. They cover six topical areas: Sun/Heliosphere, Magnetosphere/Bow Shock, Ionosphere/Atmosphere, Space Weather/Space Climate, Space Plasma Physics/Astrophysics, and Complex/Intelligent Systems.

Author: Rivera Bretel Hugo Marcelo
Publisher:
ISBN:
Category :
Languages : en
Pages : 157

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The Pierre Auger Observatory, in Argentina, combines a 3000 $\mathrm{km^2}$ surface array of water Cherenkov detectors with fluorescence telescopes to measure extensive air showers initiated by ultra-high energy cosmic rays. This "hybrid" observatory (in operation since 2004, and completed in 2008) is fully efficient for cosmic rays energies above $10^{18}$ eV, that is, from just below the "ankle" of the energy spectrum up to the highest energies.After the completion of the main observatory, the Auger collaboration has started to deploy new instruments to extend the energy range down to about 0.1 EeV. The planned extensions include two infill surface arrays with 750 and 433 m spacing, with muon detection capabilities, and three additional fluorescence telescopes with a more elevated field of view. The 750 m infill array (covering about 24 $\mathrm{km^2}$) and the new telescopes are now operational. Their aim is the measurement of cosmic rays from below the second knee of the spectrum up to the ankle, where data from the extensions overlap those from the main observatory. The study of the evolutior of the spectrum through the second knee and the ankle, together with the primary mass composition, are crucial to the understanding of the transition from a galactic cosmic ray origin to an extragalactic one.This thesis makes use of data from the 750 m infill array: the objective is the measurement of the cosmic ray energy spectrum in the energy region above $3 \times 10^{17}$ eV, where the array is fully efficient. To get to the energy spectrum, several steps are needed, from the reconstruction of events, through the precise determination of the exposure of the array, up to the determination of the primary energy. The thesis deals with these aspects, before reaching the final result.The first chapter gives a general introduction to cosmic ray physics and detectors. It also summarizes experimental results above the first knee of the spectrum with particular emphasis on those obtained above $10^{17}$ eV. The next two chapters describe the Pierre Auger Observatory and the infill array, respectively. In chapter 2, the main Auger results are summarized too, after a schematic description of th different components of the observatory. Chapter 3 sets the stage for the following chapters. It presents a more detailed description of the characteristics of the infill array, in particular the trigger definitions, event selection and reconstruction. In chapter 4 the performance of the reconstruction of the lateral distribution of observed showers is studied in detail. This is particularly important for the energy spectrum, since the signal at a fixed distance from the shower axis is used as the energy estimator of the event. This signal is estimated by means c the measured lateral distribution of the shower. Chapter 5 presents a comparison between the event reconstruction of the infill and main arrays. Using the set of showers detected by both instruments, the derived geometry and energy estimation are compared, showing a good agreement. In chapter 6, the energy threshold of the array, and hence the set of events to be used, is defined. The methods to obtain the exposure of the array are discussed, as well as related systematic uncertainties. Finally, in chapter 7, the technique to derive the primary energy for each detected shower is presented. The derived energy spectrum is discussed, and the flux is shown to be consistent with that measured by other instruments in the overlapping energy regions.

Author: Vito Di Ges—
Publisher: World Scientific
ISBN: 9812779450
Category : Science
Languages : en
Pages : 350

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This proceedings volume contains results presented at the Sixth International Workshop on Data Analysis in Astronomy OCo OC Modeling and Simulation in ScienceOCO held on April 15-22, 2007, at the Ettore Majorana Foundation and Center for Scientific Culture, Erice, Italy. Recent progress and new trends in the field of simulation and modeling in three branches of science OCo astrophysics, biology, and climatology OCo are described in papers presented by outstanding scientists. The impact of new technologies on the design of novel data analysis systems and the interrelation among different fields are foremost in scientists'' minds in the modern era. This book therefore focuses primarily on data analysis methodologies and techniques. Sample Chapter(s). Chapter 1: Simulations for Uhe Cosmic Ray Experiments (562 KB). Contents: Astrophysics, Cosmology and Earth Physics: Simulations for UHE Cosmic Ray Experiments (J Knapp); Problems and Solutions in Climate Modeling (A Sutera); Statistical Analysis of Quasar Data and Validity of the Hubble Law (S Roy et al.); Quantum Astronomy and Information (C Barbieri); Biology, Biochemistry and Bioinformatics: From Genomes to Protein Models and Back (A Tramontano et al.); Exploring Biomolecular Recognition by Modeling and Simulation (R Wade); BioInfogrid: Bioinformatics Simulation and Modeling Based on Grid (L Milanesi); Methods and Techniques: Optimization Strategies for Modeling and Simulation (J Louchet); Biclustering Bioinformatics Data Sets: A Possibilistic Approach (F Masulli); From the Qubit to the Quantum Search Algorithms (G Cariolaro & T Occhipinti); Comparison of Stereo Vision Techniques for Cloud-Top Height Retrieval (A Anzalone et al.); and other papers. Readership: Physicists; biologists; computer scientists and data analysts."

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 162

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Ultra-high-energy cosmic rays (UHECR) are particles of uncertain origin and composition, with energies above 1 EeV (1018 eV or 0.16 J). The measured flux of UHECR is a steeply decreasing function of energy. The largest and most sensitive apparatus built to date to record and study cosmic ray Extensive Air Showers (EAS) is the Pierre Auger Observatory. The Pierre Auger Observatory has produced the largest and finest amount of data ever collected for UHECR. A broad physics program is being carried out covering all relevant topics of the field. Among them, one of the most interesting is the problem related to the estimation of the mass composition of cosmic rays in this energy range. Currently the best measurements of mass are those obtained by studying the longitudinal development of the electromagnetic part of the EAS with the Fluorescence Detector. However, the collected statistics is small, specially at energies above several tens of EeV. Although less precise, the volume of data gathered with the Surface Detector is nearly a factor ten larger than the fluorescence data. So new ways to study composition with data collected at the ground are under investigation. The subject of this thesis follows one of those new lines of research. Using preferentially the time information associated with the muons that reach the ground, we try to build observables related to the composition of the primaries that initiated the EAS. A simple phenomenological model relates the arrival times with the depths in the atmosphere where muons are produced. The experimental confirmation that the distributions of muon production depths (MPD) correlate with the mass of the primary particle has opened the way to a variety of studies, of which this thesis is a continuation, with the aim of enlarging and improving its range of applicability. We revisit the phenomenological model which is at the root of the analysis and discuss a new way to improve some aspects of the model. We carry out a thorough revision of the original analysis with the aim of understanding the different contributions to the total bias and resolution when building MPDs on an event-by-event basis. We focus on an alternative way to build MPDs by considering average MPDs for ensembles of air-showers, with the aim of enlarging the range of applicability of this kind of analysis. Finally, we analyze how different improvements in the Surface Detector electronics and its internal configuration affect the resolution of the MPD. We conclude by summarizing the main results and discussing potential ways to improve MPD-based mass composition studies.