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 Energy Spectrum Measured by the Telescope Array Surface Detector written by Dmitri Ivanov and published by . This book was released on 2012 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two conflicting measurements of the ultra high energy cosmic ray (UHECR) flux have been reported by the Akeno Giant Air Shower Array (AGASA) and the High Resolution Fly's Eye (HiRes) experiments. HiRes observes a $sim$5$sigma$ suppression at $E=10^{19.75}$ eV, which is in agreement with the prediction of Greisen-Zatsepin-Kuz'min (GZK) theory. AGASA, in contrast, sees the flux extended well beyond $E=10^{20}$ eV with no visible break, suggesting that the flux is limited only by the rate at which the sources can produce the UHECR and not by interaction of energetic particles with the cosmic microwave background, thus challenging the relativistic invariance principle. In response to this discrepancy, a new experiment named the Telescope Array (TA) has been deployed, which combines the detection elements used separately by HiRes and AGASA. We describe the TA surface detector (SD) analysis using a technique new to the field, which consists of a detailed Monte-Carlo (MC) simulation of the SD response to the natural cosmic rays, validating the MC by comparing its distributions with the data, and calculation of the SD aperture from the MC. We will also describe our reconstruction procedure, based solely upon the data, and its application to both data and the MC. Finally, we will describe the energy spectrum resulting from this analysis, which is found to be in excellent agreement with the HiRes result, and as such, is the first confirmation of the GZK effect by a ground array of scintillation counters.

Download or read book Emission of Radio Waves in Particle Showers written by Anne Zilles and published by Springer. This book was released on 2017-08-08 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis offers the first laboratory validation of microscopic simulations of radio emission from particle showers, including a detailed description of the simulation study. It presents a potential future avenue for resolving the mass composition of cosmic rays via radio detection of air showers. Particle showers are created from cascading interactions when high-energy particles collide with matter, e.g. with air in the case of cosmic radiation, or with a particle detector in the case of experiments at CERN. These showers can consist of billions of particles, mostly electrons, positrons and photons. They emit radio waves when the absorbing medium is in a magnetic field, and this radio emission can be used as a novel means of detecting and drawing inferences on the shower and the primary particle. The new method is currently being established in cosmic ray research, where large antenna arrays may soon replace or complement traditional particle detectors. In thi s study, a complete microscopic simulation of a radio-emission experiment conducted at Stanford Linear Accelerator Center (SLAC), Stanford/USA, is performed, and the underlying physical models are validated. The model is subsequently applied to the Square Kilometre Array (SKA) project, which is a large interferometer for radio astronomy. It is demonstrated that the SKA, with some modifications, might also be used for cosmic ray research based on radio detection of high-energy particles from the cosmos.

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 Measurement of the Flux of Ultra high Energy Cosmic Rays by the Telescope Array FADC Fluorescence Detectors written by Sean Stratton and published by . This book was released on 2012 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra-high energy cosmic rays (UHECRs) produce the most powerful collisions between single particles and atmospheric matter. They have been studied since the early 20th century yet, to this date, there is no clear answer as to the acceleration process responsible for their produc-tion. The Telescope Array Project is an experiment designed to observe the showers of particles produced as by-products of the interactions between UHECRs and the atmosphere. As a hybrid experiment, it currently utilizes 38 fluorescence detectors (FDs) divided between three sites over-looking an array of 507 surface detectors (SDs). The project's mission is to study the energy, composition and origin of UHECRs using a variety of techniques which may include some or all of the experiment's apparatus. This document, in particular, is a presentation of the UHECR en-ergy spectrum measured at Telescope Array using the fluorescence detection technique in mo-nocular mode. Only data from the 24 FDs at Black Rock Mesa (BR) and Long Ridge (LR) sta-tions are used here.

Download or read book On the Energy Estimation of Ultra High Energy Cosmic Rays Observed with the Surface Detector Array written by H. Y. Dai and published by . This book was released on 1988 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Calibration of the Surface Array of the Pierre Auger Observatory written by and published by . This book was released on 2005 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ground array of the Pierre Auger Observatory consists of 1600 water Cherenkov detectors, deployed over 3000 km2. The remoteness and large number of detectors required a simple, automatic remote calibration procedure. The primary physics calibration is based on the average charge deposited by a vertical and central throughgoing muon, determined with good precision at the detector via a novel rate-based technique and later with higher precision via charge histograms. This value is named the vertical-equivalent muon (VEM). The VEM and the other parameters needed to maintain this calibration over the full energy range and to assess the quality of the detector are measured every minute. This allows an accurate determination of the energy deposited in each detector when an atmospheric cosmic ray shower occurs.

Download or read book Antenna Calibration and Energy Measurement of Ultra High Energy Cosmic Rays with the Auger Engineering Radio Array written by Klaus Frank Weidenhaupt and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Cosmic Ray Flux Above 100 PeV at the Pierre Auger Observatory written by Alan Coleman and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmic rays are particles and nuclei that arrive at Earth and act as messengers, informing us of the nature of celestial objects and events throughout the universe. Some of the highest energy events, with over a Joule of energy, are more energetic than what can be made on Earth in modern particle accelerators. In the ultra-highenergy range > 100 PeV, the arrival rate is low enough (1 per km 2 per year, or less) that there are still many outstanding questions concerning their origin and what types of particles they are. Further, their rarity presents an experimental challenge as direct detection of cosmic rays above this energy would require decades to centuries of data collection. Instead, the particles cascades created by ultra-high energy cosmic rays interacting with air molecules high in the atmosphere, called air showers, can be detected using observatories that cover 10-1000 km^2 . The Pierre Auger Observatory includes a number of methods to detect air showers and covers over 3000 km^2 in the Mendoza Province of Argentina. The Observatory includes a hybrid design by which air showers can be detected by fluorescence detectors while they are developing in the air as well as by an array of surface detectors on the ground. This thesis includes an extensive update to the reconstruction methods used to estimate the trajectory and energy of a cosmic ray using a hexagonal array of water Cherenkov detectors with 750 m spacing. The update was motivated by the inclusion of a new set of particle triggers that were installed in the local stationsthat make up the array. These triggers were designed to be insensitive to muons which make up the primary background for individual stations. Thus, they increase the sensitivity of the array to lower energy parts of air showers and lower energy showers in general.A major component of this work was the characterization of the arrays abilities to detect and sample air showers with the new trigger algorithms. On the level of individual stations, the triggering efficiency and distribution of signals was studied. On the array-level, the efficiency with which the 750 m array detects showers was also calculated for two sets of cosmic ray masses using a dedicated set of air shower simulations based on hadronic interaction models.The second component of this thesis was an improvement of Augers model of air shower development. Due to a lack of understanding of hadronic cross sections in the ultra-high energy regime, empirical models are used to characterize the temporal and spatial distribution of particles within the cascade. The distributionof signal as a function of distance from an air showers central axis was updated, benefiting from the 30% more sampling of the shower front by new-triggered stations. This model is particularly important as it is used to find the expected signal at a fixed reference distance from the axis to estimate the showers size, a quantity highly correlated to energy. These size estimations were then corrected for a number of systematic biases to produce a more precise energy estimator. Finally, the energy estimators were cross-calibrated with the nearly calorimetric energy measurements made by the fluorescence detectors. This allowed for the surface detector to directly estimate energies accurate to within E/E = 14-15%.Motivated by the parameter space where the array can detect showers with full efficiency, two semi-joint data sets were chosen which included energies and zenith angles (E > 10^17 eV, 40 ) and (E 10^17.3 eV,

Download or read book Upper Limits on the Ultra high Energy Cosmic Ray Flux from Unresolved Sources written by Ross E. Burton and published by . This book was released on 2012 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Observatory is the world's largest ultra-high energy cosmic ray detector. Its goals include answering basic questions about the origins and composition of cosmic rays at the highest energies. We outline the scientific motivation for constructing such an observatory and we highlight some of the significant results produced so far by this world-class instrument. We present the results of our own contributions toward calibrating the timing characteristics of the instrument followed by two alternative techniques for analyzing cosmic ray arrival direction data. The first technique is based on a Bayesian statistical framework and is presented as a solution to some of the difficulties in applying a standard analysis to identify anisotropy in the cosmic ray flux. The second analysis we present is based on a Markov Chain Monte Carlo method for identifying sources of cosmic rays in our arrival direction data. We are able to use our method to set an upper limit of 0.15 per square km per year on the flux from any potential sources producing ultra-high energy cosmic rays with energy E{u2265}3 EeV. We conclude with a proposal for enhancing the already successful observatory with an array of non-imaging Cherenkov detectors. According to our simulation work, such an array could serve as both an independent measure of the cosmic ray energy and, if the array is dense enough, it could also provide insight into the composition of ultra-high energy cosmic rays on an event by event basis.

Download or read book Microwave Detection of Cosmic Rays and Multi messenger Analysis of the Parameters of Ultra high Energy Astrophysical Sources written by Nathan E. Griffith and published by . This book was released on 2015 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of ultra-high energy (UHE) cosmic particles is frequently characterized by its low statistics, and a central problem of the field is to find novel ways to navigate this challenge. The research presented in this dissertation attempts to address this problem in two ways: first, by investigating microwave radiation as a new method of UHE cosmic ray detection, and second, by using a multi-messenger (proton and neutrino) analysis to determine what current and next generation UHE neutrino detectors may be able to reveal about UHE astrophysical sources. The cosmic ray detector (called AMBER) is primarily a joint collaboration between Ohio State and the University of Hawaii. In May/June 2011 the AMBER experiment was installed at the Pierre Auger Observatory in Malargue, Argentina, and began taking data in coincidence with the observatory's surface detector array. This work presents a description of the experiment, a calibration based on an astrophysical radio source (the Milky Way galaxy), and an analysis of data. The second half of this document describes a multi-messenger analysis performed with co-authors Amy Connolly and Shunsaku Horiuchi on a publication in preparation. Fits to Pierre Auger 2013 data are used in conjunction with a spectral model and simulations of UHE neutrino detectors to explore the UHE source parameters of cosmic evolution and source spectrum cutoff. Constraints provided using the effective areas of the ANITA 3, ARA, and EVA detectors are considered.

Download or read book Determining Primaries in the Ultra high Energy Cosmic Rays Utilizing Surface Detector Signal Trace Analysis written by James D. Chye and published by . This book was released on 2007 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Pierre Auger Observatory Scaler Mode for the Study of Solar Activity Modulation of Galactic Cosmic Rays written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Since data-taking began in January 2004, the Pierre Auger Observatory has been recording the count rates of low energy secondary cosmic ray particles for the self-calibration of the ground detectors of its surface detector array. After correcting for atmospheric effects, modulations of galactic cosmic rays due to solar activity and transient events are observed. Temporal variations related with the activity of the heliosphere can be determined with high accuracy due to the high total count rates. In this study, the available data are presented together with an analysis focused on the observation of Forbush decreases, where a strong correlation with neutron monitor data is found.

Download or read book JEM EUSO Prototypes for the Detection of Ultra high energy Cosmic Rays UHECRs written by Aera Jung and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The JEM-EUSO (Extreme Universe Space Observatory on-board the Japanese Experiment Module) international space mission is designed to observe UHECRs by detecting the UV fluorescence light emitted by the so-called Extensive Air Shower (EAS) which develop when UHECRs interact with the Earth's atmosphere. The showers consist of tens of billions or more secondary particles crossing the atmosphere at nearly the speed of light, which excite nitrogen molecules which then emit light in the UV range. While this so-called “fluorescence technique'” is routinely used from the ground, by operating from space, JEM-EUSO will, for the first time, provide high-statistics on these events. Operating from space, with a large Field-of-View of ±30 °, allows JEM-EUSO to observe a much larger volume of atmosphere, than possible from the ground, collecting an unprecedented number of UHECR events at the highest energies.For the four pathfinder experiments built within the collaboration, we have been developing a common set of electronics, in particular the central data acquisition system, capable of operating from the ground, high altitude balloons, and space.These pathfinder experiments all use a detector consisting of one Photo-detection Modules (PDMs) identical to the 137 that will be present on the JEM-EUSO focal surface. UV light generated by high-energy particle air showers passes the UV filter and impacts the Multi-anode Photomultiplier Tubes (MAPMT). Here UV photons are converted into electrons, which are multiplied by the MAPMTs and fed into Elementary Cell Application-Specific Integrated Circuit (EC-ASIC) boards, which perform the photon counting and charge estimation. The PDM control board interfaces with these ASIC boards, providing power and configuration parameters, collecting data and performing the level 1 trigger. I was in charge of designing, developing, integrating, and testing the PDM control board for the EUSO-TA and EUSO-Balloon missions as well as the autonomous trigger algorithm testing and I also performed some analysis of the EUSO-Balloon flight data and data from the EUSO-TA October 2015 run.In this thesis, I will give a short overview of high-energy cosmic rays, including their detection technique and the leading experiments (Chapter 1), describe JEM-EUSO and its pathfinders including a description of each instrument (Chapter 2), present the details of the design and the fabrication of the PDM (Chapter 3) and PDM control board (Chapter 4), as well as the EUSO-TA and EUSO-Balloon integration tests (Chapter 5). I will report on the EUSO-Balloon campaign (Chapter 6) and results (Chapter 7), including a specific analysis developed to search for global variations of the ground UV emissivity, and apply a similar analysis to data collected at the site of Telescope Array (Chapter 8). Finally, I will present the implementation and testing of the first-level trigger (L1) within the FPGA of the PDM control board (Chapter 9). A short summary of the thesis will be given in Chapter 10.

Download or read book Instruments and Methods for the Radio Detection of High Energy Cosmic Rays written by Frank Schröder and published by Springer Science & Business Media. This book was released on 2012-12-14 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmic rays consist of elementary particles with enormous energy which originate from outside our solar system and constantly hit the Earth’s atmosphere. Where do these cosmic rays originate? How does nature accelerate the cosmic-ray particles to energies with orders of magnitude beyond the limits of manmade particle accelerators? What can we learn by measuring the interactions of the cosmic rays with the atmosphere? Digital radio-antenna arrays offer a promising, complementary measurement method for high-energy cosmic rays. This thesis reports on substantial advances in the development of the radio technique, which will be used to address these questions in future experiments.

Download or read book Composition Analysis of Ultrahigh Energy Cosmic Rays Using the Pierre Auger Observatory Surface Detector written by David Scott Barnhill and published by . This book was released on 2006 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: The origin and composition of ultrahigh energy cosmic rays has been and continues to be a topic of much study and debate. The Pierre Auger Observatory was designed to investigate the highest energy cosmic rays and resolve some of these problems. In this dissertation, I present a description of the Pierre Auger Observatory and a study of the performance of the surface array as well as work done on the photomultiplier tubes used in the surface array. I also present an analysis done on the composition of the events detected in the surface detector paying special attention to a photon primary assumption. Monte carlo simulations of extensive air showers are put through a simulation of the surface detector and observables are compared to real data. The mean behavior of the real data is compared to various baryonic primary assumptions. For photon primaries, a method is described to set an upper limit on the flux of photons based on comparing real events to expected distributions for photon initiated air showers. An upper limit on the photon flux is presented and compared with predictions from various exotic models of cosmic ray origins.

Download or read book The Exposure of the Hybrid Detector of the Pierre Auger Observatory written by and published by . This book was released on 2010 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The 'hybrid' detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure. We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction.