Download or read book Measurement of the Energy Spectrum of Cosmic Rays Above 3 X 1017 EV Using the Infill Array of the Pierre Auger Observatory written by Rivera Bretel Hugo Marcelo and published by . This book was released on 2013 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Cosmic Rays and Particle Physics written by and published by Cambridge University Press. This book was released on with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Cosmic Ray Spectrum Above 4 1018 EV Using Inclined Events Detected with the Pierre Auger Observatory written by and published by . This book was released on 2015 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×1018 eV, the ``ankle'', the flux can be described by a power law E-[gamma] with index [gamma]=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0-1.2 (sys))×1019 eV.
Download or read book Astroparticle Particle Space Physics And Detectors For Physics Applications Proceedings Of The 14th Icatpp Conference written by Simone Giani and published by World Scientific. This book was released on 2014-06-02 with total page 827 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exploration of the subnuclear world is done through increasingly complex experiments covering a wide range of energy and performed in a large variety of environments ranging from particle accelerators, underground detectors to satellites and the space laboratory. The achievement of these research programs calls for novel techniques, new materials and instrumentation to be used in detectors, often of large scale. Therefore, fundamental physics is at the forefront of technological advance and also leads to many applications. Among these, are the progresses from space experiments whose results allow the understanding of the cosmic environment, of the origin and evolution of the universe after the Big Bang.
Download or read book Measurement of the Cosmic Ray Spectrum Above 4 u00D7 1018 EV Using Inclined Events Detected with the Pierre Auger Observatory written by and published by . This book was released on 2015 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×1018 eV, the à̀nkle'', the flux can be described by a power law E–? with index ?=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0–1.2 (sys))×1019 eV.
Download or read book Measurement of the Energy Spectrum of Ultra high Energy Cosmic Rays Using Hybrid Data of the Pierre Auger Observatory written by Fabian Schüssler and published by . This book was released on 2009 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Features of the Energy Spectrum of Cosmic Rays Above 2 5 times 10 18 EV Using the Pierre Auger Observatory written by Alexander Aab and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book First estimate of the primary cosmic ray energy spectrum above 3 EeV from the Pierre Auger Observatory written by Paul Sommers and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of air showers are accumulating at an increasing rate while construction proceeds at the Pierre Auger Observatory. Although the southern site is only half complete, the cumulative exposure is already similar to those achieved by the largest forerunner experiments. A measurement of the cosmic ray energy spectrum in the southern sky is reported here. The methods are simple and robust, exploiting the combination of fluorescence detector (FD) and surface detector (SD). The methods do not rely on detailed numerical simulation or any assumption about the chemical composition.
Download or read book Measurement of the Cosmic Ray Energy Spectrum Using Hybrid Events of the Pierre Auger Observatory written by and published by . This book was released on 2012 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Cosmic Ray Spectrum at the Highest Energy written by Alessio Gorgi and published by . This book was released on 2009 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book The Energy Spectrum of Cosmic Rays Measured with the HEAT Extension at the Pierre Auger Observatory written by Nils Sven Sebastian Scharf and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design Calibration and Early Results of a Surface Array for Detection of Ultrahigh Energy Cosmic Rays written by Patrick S. Allison and published by . This book was released on 2007 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: The difficulties in understanding cosmic rays at ultrahigh energies have been a persistent problem in particle astrophysics for almost 50 years, due to insufficient statistics and large systematic errors. The design of a surface array for the Pierre Auger Observatory, which was intended to resolve these problems, will be discussed, along with its calibration. The surface detector is an array of 1600 water Cherenkov detectors, spaced 1.5 km apart for a total area of 3000 km2, planned to operate continuously for 20 years. The detectors therefore must be inexpensive, low power, easy to deploy, and have a high reliability. Each surface detector station is required to make a high precision measurement of the signal density produced by the air showers induced by cosmic rays over a wide dynamic range, and therefore a calibration system was developed for the array which creates a signal response uniform to within 3%. Finally, early results of the cosmic ray energy spectrum will be calculated, along with the future implications of the array for the field of cosmic ray astrophysics as well as physics in general.
Download or read book Measuring the Cosmic ray Energy Spectrum Composition and Anisotropy at PeV Scales Using the IceCube Observatory written by James Bourbeau and published by . This book was released on 2019 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of cosmic rays over one hundred years ago, many experiments have studied their properties. However, a definitive answer to the questions of where cosmic rays originate and how they are produced is still not known. Over the last several decades, a much more detailed understanding of high energy cosmic rays has begun to materialize. In particular, the cosmic-ray energy spectrum, with its transitions at 3 PeV (the "knee") and 3 EeV (the "ankle"), has been extensively investigated. Based on magnetic confinement arguments, it's generally believed that the energy range between the knee and ankle is where the transition from Galactic to extragalactic sources of cosmic rays. The ability to distinguish between high energy cosmic rays of different composition and study the relative mass abundances of cosmic rays in this transition region can provide invaluable insight in answering the open questions surrounding the origins of cosmic rays. This work focuses on measuring the composition-resolved cosmic-ray energy spectrum at and above the all-particle knee using one year of data collected by the IceCube Observatory. Sepcifically, we focus on making a two mass group spectrum measurement from 10^6.4 GeV to 10^7.8 GeV. The first mass group, referred to as the "light" mass group, is modeled using proton and helium cosmic rays, while the second, "heavy" mass group, is modeled using oxygen and iron cosmic rays. We observe a clear softening of the light spectrum near 3 PeV, while the energy spectrum for the heavy mass group follows a power-law like structure with a spectral index of ~2.7 throughout the entire energy range considered. The observed transition from a primarily light to a heavy-dominant spectrum takes place near 10^7.1 GeV. This feature is characteristic of a potential rigidity-dependent cutoff, or Peters cycle. The change in relative mass abundance could also indicate a possible transition in the source population of cosmic rays. In addition, a study to determine whether or not the light, heavy, or all-particle cosmic-ray energy spectra vary as a function of arrival direction is also presented. This marks the first time an analysis of this kind has been conducted using the IceCube Observatory. No statistically significant spectrum deviations were observed. The results from this analysis can be used to set a limit on the range of possible spectral deviations.
Download or read book Proceedings written by and published by . This book was released on 2005 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Pierre Auger Observatory I written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Mass Composition of the Highest Energy Cosmic Rays with the Pierre Auger Observatory written by Alexander Edward Hervé and published by . This book was released on 2013 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The origin of ultra high energy cosmic rays is one of the big unsolved questions in Astrophysics today. Knowing the mass composition of these cosmic rays would help to determine information about both their propagation and acceleration. The Pierre Auger Observatory was built to gather more information and more statistics than any previous cosmic ray detector ever built. In this thesis, I will detail my method of extending the current Pierre Auger mass composition information by using surface array parameters as a proxy for the depth of shower maximum, an established mass indicator.
Download or read book Science written by John Michels (Journalist) and published by . This book was released on 2007 with total page 916 pages. Available in PDF, EPUB and Kindle. Book excerpt:
