Download or read book The Mass Composition of Cosmic Rays Above 1 EeV Inferred Using the Spread in Arrival Times of Air Shower Particles written by Benjamin Edward Smith and published by . This book was released on 2008 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mass Composition Studies of Ultra High Energy Cosmic Rays Through the Measurement of the Muon Production Depths at the Pierre Auger Observatory written by Laura Collica and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Observatory studies Ultra High Energy Cosmic Rays (UHECRs) physics. The flux of UHECRs is very low (less than 1 particle/km2-year) and their properties must be inferred from the measurements of the secondary particles that the cosmic ray primary produces in the atmosphere. These particles cascades are called Extensive Air Showers (EAS) and can be studied at ground by deploying detectors covering large areas. The EAS physics is complex, and the properties of secondary particles depend strongly on the first interaction, which takes place at an energy beyond the ones reached at accelerators. As a consequence, the analysis of UHECRs is subject to large uncertainties and hence many of their properties, in particular their composition, are still unclear. Two complementary techniques are used at Auger to detect EAS initiated by UHECRs: a 3000 km2 surface detector (SD) array of water Cherenkov tanks which samples particles at ground level and fluorescence detectors (FD) which collect the ultraviolet light emitted by the de-excitation of nitrogen nuclei in the atmosphere, and can operate only in clear, moonless nights. The main goal of this thesis is the measurement of UHECR mass composition using data from the SD of the Pierre Auger Observatory. Measuring the cosmic ray composition at the highe-st energies is of fundamental importance for particle physics and astrophysics. Indeed, it allows to explore the hadronic interactions at ultra-high energies, and to discriminate between different scenarios of origin and propagation of cosmic rays.
Download or read book Ultra high Energy Cosmic Rays written by James Stapleton and published by . This book was released on 2015 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Cosmic Rays written by A. M. Hillas and published by Elsevier. This book was released on 2013-10-22 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmic Rays is a two-part book that first elucidates the discovery, nature, and particles produced by cosmic rays. This part also looks into the primary cosmic radiation; radio waves from the galaxy; extensive air showers; origin of cosmic rays; and other cosmic radiations. Part 2 consists of reprinted papers involving cosmic rays. Papers 1 to 10 treat the nature of the radiation, arranged chronologically; in Papers 11 to 16 the scene moves away from the Earth.
Download or read book Ultra high Energy Particle Astrophysics written by Shigeru Yoshida and published by Nova Publishers. This book was released on 2003 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many kinds of radiation exist in the universe, including photons and particles with a wide range of energies. Some of the radiation is produced in stars and galaxies, and some is cosmological background radiation, a relic from the history of cosmic evolution. Among all this radiation, the most energetic are cosmic ray particles: nucleons, nuclei, and even extremely energetic gamma rays. There are some observational facts about cosmic rays to give suggestions on their origin. The most important one among them is that the energy spectrum of high energy cosmic rays above 10 GeV (where the magnetic field of the sun is no longer a concern) is well represented by a power law form. This indicates cosmic ray particles are products of non-thermal processes. Their energy extends over more than 13 decades from 107 eV up to 1020 eV. In terms of its structure, the spectrum can be divided into three regions: two 'knees' and one 'ankle'. The first 'knee' appears around 3×1015 eV where the spectral power law index changes from -2.7 to -3.0. The second 'knee' is somewhere between 1017 eV and 1018 eV where the spectral slope changes from -3.0 to around -3.3. The 'ankle' is seen at or after 3×1018 eV. Above that energy the spectral slope is around -2.7, but with a large uncertainty because of poor statistics and resolution. This book deals with the final and most energetic population, the Ultra High Energy Cosmic Rays (UHECRs).
Download or read book High Energy Cosmic Rays written by Todor Stanev and published by Springer Science & Business Media. This book was released on 2010-03-10 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers an accessible text and reference (a cosmic-ray manual) for graduate students entering the field and high-energy astrophysicists will find this an accessible cosmic-ray manual Easy to read for the general astronomer, the first part describes the standard model of cosmic rays based on our understanding of modern particle physics. Presents the acceleration scenario in some detail in supernovae explosions as well as in the passage of cosmic rays through the Galaxy. Compares experimental data in the atmosphere as well as underground are compared with theoretical models
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2009 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysical Aspects Of The Most Energetic Cosmic Rays Proceedings Of The Icrr International Symposium written by M Nagano and published by World Scientific. This book was released on 1991-07-23 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings present new results obtained from recent observations by the Haverah Park, Yakutsk, Fly's Eye and Akeno groups on the shape of the energy spectrum, the arrival direction (point source) and the nature of the most energetic cosmic rays. They also contain an in-depth discussion of the present status of observations on discrete sources at TeV and PeV energies. A detailed discussion of the physics problems related to the origin, acceleration mechanism and propagation of the most energetic cosmic rays in the galactic and extragalactic space is given in relation to observable features.
Download or read book Effects of the Primary Cosmic Radiation on Matter written by Harold Curtis and published by . This book was released on 1956 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Composition of Cosmic Rays in the Knee Region of the Spectrum Using the Underground Soundan2 Detector and a Surface Air Shower Array written by Richard William Gran and published by . This book was released on 2002 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evidence for a Mixed Mass Composition at the ankle in the Cosmic ray Spectrum written by and published by . This book was released on 2016 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, we report a first measurement for ultra-high energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the `ankle' at $\lg(E/{\rm eV})=18.5-19.0$ differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass $A> 4$. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth.
Download or read book A SEARCH FOR MASSIVE PARTICLES IN COSMIC RAYS written by and published by . This book was released on 1967 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Determining the Mass Composition of Ultra high Energy Cosmic Rays Using Air Shower Universality written by Ariel Bridgeman and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elementary Particles and Cosmic Rays written by A M Gal'per and published by . This book was released on 1959 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of the Highest Energy Cosmic Ray Air Showers with the Pierre Auger Observatory Hybrid Dectector written by Bei Cai and published by . This book was released on 2006 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of the Mass of Cosmic Ray Particles from Their Ionizing Power written by Artemii Isaakovich Alikhanian and published by . This book was released on 1954 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
