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Study of downward terrestrial gamma-ray flashes the the Telescope Array

In this paper the technological aspects of the FAZIA array will be explored. After a productive commissioning phase, FAZIA blocks started to measure and give very useful data to explore the physics of Fermi energy heavy-ion reactions. This was possible thanks to many technical measures and innovations developed in the commissioning phase and tuned during the first experimental campaigns. This paper gives a detailed description of the present status of the FAZIA setup from the electronic and mechanical point of view, trying also to trace a path for new improvements and refinements of the apparatus., 17 pages, 9 figures

The Telescope Array (TA) is the largest ultrahigh energy cosmic ray detector in the northern hemisphere. The experiment consists of three fluorescence stations viewing the air space over a surface array of 507 scintillation counters deployed over 700 square kilometers. TA has been in operation since 2008. The most recent results from TA, including that of composition studies and search for arrival direction anisotropy, will be presented. We will also report on the progress of the new TA low energy extension (TALE).

Active galactic nuclei (AGN) are believed to be one of the main source candidates for the high-energy (TeV-PeV) cosmic neutrino flux recently discovered by the IceCube neutrino observatory. Nevertheless, several correlation studies between AGN and the cosmic neutrinos detected by IceCube show no significance. Therefore, in this article we consider a specific subclass of AGN for which an increased neutrino production is expected. This subclass contains AGN for which their high-energy jet is pointing toward Earth. Furthermore, we impose the condition that the jet is obscured by gas or dust surrounding the AGN. A method is presented to determine the total column density of the obscuring medium, which is probed by determining the relative x-ray attenuation with respect to the radio flux as obtained from the AGN spectrum. The total column density allows us to probe the interaction of the jet with the surrounding matter, which leads to additional neutrino production. Finally, starting from two different source catalogs, this method is applied to specify a sample of low redshift radio galaxies for which an increased neutrino production is expected.

TARA (Telescope Array Radar) is a cosmic ray radar detection experiment co- located with Telescope Array, the conventional surface scintillation detector (SD) and fluorescence telescope detector (FD) near Delta, UT. The TARA detector combines a 40 kW transmitter and high gain transmitting antenna which broadcasts the radar carrier over the SD array and in the FD field of view to a 250 MS/s DAQ receiver. Data collection began in August, 2013. TARA stands apart from other cosmic ray radar experiments in that radar data is directly compared with conventional cosmic ray detector events. The transmitter is also directly controlled by TARA researchers. Waveforms from the FD-triggered data stream are time-matched with TA events and searched for signal using a novel signal search technique in which the expected (simulated) radar echo of a particular air shower is used as a matched filter template and compared to radio waveforms. This technique is used to calculate the radar cross-section (RCS) upper-limit on all triggers that correspond to well-reconstructed TA FD monocular events. Our lowest cosmic ray RCS upper-limit is 42 cm^2 for an 11 EeV event. An introduction to cosmic rays is presented with the evolution of detection and the necessity of new detection techniques, of which radar detection is a candidate. The software simulation of radar scattering from cosmic rays follows. The TARA detector, including transmitter and receiver systems, are discussed in detail. Our search algorithm and methodology for calculating RCS is presented for the purpose of being repeatable. Search results are explained in context of the usefulness and future of cosmic ray radar detection.

Article, The Physical Society of Japan

We are conducting tests of optical and electronics components of JEM-EUSO at the Telescope Array site in Utah with a ground-based "EUSO-TA" detector. The tests will include an engineering validation of the detector, cross-calibration of EUSO-TA with the TA fluorescence detector and observations of air shower events. Also, the proximity of the TA?s Electron Light Source will allow for convenient use of this calibration device. In this paper, we report initial results obtained with the EUSO-TA telescope. Fil: Adams, J. H.. University of Alabama in Huntsville; Estados Unidos Fil: Ahmad, S.. Ecole Polytechnique; Francia Fil: Albert, J. N.. Univ Paris-Sud; Francia Fil: Allard, D.. Univ Paris Diderot; Francia Fil: Anchordoqui, L.. University of Wisconsin-Milwaukee; Estados Unidos Fil: Andreev, V.. University of California; Estados Unidos Fil: Anzalone, A.. INAF - Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo; Italia Fil: Arai, Y.. High Energy Accelerator Research Organization (KEK); Japón Fil: Asano, K.. Tokyo Institute of Technology; Japón Fil: Ave Pernas, M.. Universidad de Alcala (UAH); España Fil: Barrillon, P.. Univ Paris-Sud; Francia Fil: Batsch, T.. Lomonosov Moscow State University; Rusia Fil: Bayer, J.. University of Tubingen; Alemania Fil: Bechini, R.. Universita’ di Torino; Italia Fil: Belenguer, T.. Instituto Nacional de Tecnica Aeroespacial (INTA); España Fil: Bellotti, R.. Istituto Nazionale di Fisica Nucleare; Italia Fil: Belov, K.. University of California; Estados Unidos Fil: Berlind, A. A.. Vanderbilt University; Estados Unidos Fil: Bertaina, M.. Istituto Nazionale di Fisica Nucleare; Italia Fil: Biermann, P. L.. Karlsruhe Institute of Technology (KIT); Alemania Fil: Biktemerova, S.. Joint Institute for Nuclear Research; Rusia Fil: Blaksley, C.. Univ Paris Diderot; Francia Fil: Blanc, N.. Swiss Center for Electronics and Microtechnology (CSEM); Suiza Fil: Blacki, J.. Space Research Centre of the Polish Academy of Sciences (CBK); Polonia Fil: Blin Bondil, S.. Ecole Polytechnique; Francia Fil: Blumer, J.. Karlsruhe Institute of Technology (KIT); Alemania Fil: Bobik, P.. Institute of Experimental Physics; Eslovaquia Fil: Bogomilov, M.. University of Sofia; Bulgaria Fil: Bonamente, M.. University of Alabama in Huntsville; Estados Unidos Fil: Supanitsky, Alberto Daniel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Kawasaki, Yoshiya. RIKEN; Japón Fil: Piotrowski, Lech Wiktor. RIKEN; Japón Fil: Kawasaki, Yoshiya. Yoshiya; Japón Fil: Piotrowski, Lech Wiktor. Yoshiya; Japón Fil: The JEM-EUSO Collaboration ·.

The chemical composition of cosmic rays is critically important to understanding cosmic ray sources as well as a cosmic ray's propagation through the Galaxy and Universe. Theories explaining the features seen in the cosmic ray spectrum depend strongly on the chemical composition of cosmic rays. Composition has implications for anisotropy studies as atomic nuclei with large atomic number are more susceptible to deflection by Galactic and extragalactic magnetic fields. This work presents a composition analysis using data from the Telescope Array (TA) experiment and uses the point of shower maximum, Xmax, as the marker of a cosmic ray's chemical composition. TA is the largest cosmic ray detector in the Northern Hemisphere and makes use of both ground array as well as nitrogen fluorescence methods for detecting cosmic rays. This analysis combines both ground array and fluorescence data in a hybrid analysis to obtain resolutions of 0.5◦ in reconstructed pointing directions and 20 g/cm2 in reconstructed Xmax. Above 1018.5 eV, measured Xmax distributions using hybrid TA data are compatible with proton MC and exclude iron. However, above 1019.3 eV, the statistical power is limited and the data is compatible either proton or iron MCs. The shapes of the Xmax distributions independent of their means are compared, showing again that the data is compatible with protons and incompatible with iron. However, the statistical power for this measurement is limited above 1018.8 eV.

Cosmic radiation was discovered in 1912. This year, the 100th anniversary of the discovery, marks not only the major progress that has been made in understanding these particles, but also the remaining questions about them. Questions about their sources, acceleration mechanisms, propagation and composition are still unanswered. There are only two experiments currently running that have the ability to study cosmic rays in the Ultra High Energy (E > 1018'0 eV) regime. The Telescope Array studies Ultra High Energy Cosmic Rays (UHECRs) using a hybrid detector. Fluorescence telescopes measure the longitudinal development of the extensive air shower generated by a primary cosmic ray particle, while scintillator detectors measure the lateral distribution of secondary particles that hit the ground. The Middle Drum (MD) fluorescence telescope consists of 14 refurbished telescopes from the High Resolution Fly's Eye (HiRes) experiment, providing a direct link back to the HiRes experiment and data. The surface array is comprised of 507 Scintillator Detectors (SD) of a similar design as was used by the Akeno Giant Air Shower Array (AGASA), providing a link to that experiment as well. Studying TA hybrid events (events observed by both the FD and SD), makes the analysis presented in this work the lynchpin that connects the HiRes experiment to the AGASA experiment. This uniquely allows for a direct comparison between the two detection types and allows us to answer questions about the differences in the energy spectrum measurements shown by the two previous experiments. Furthermore, the hybrid analysis improves the geometrical reconstruction of the showers significantly. This provides a more accurate measurement of the energy of the primary particle and makes it possible to make an accurate prediction regarding the chemical composition of the cosmic ray particle. Historically, only the HiRes experiment and the Pierre Auger Observatory (PAO) have made significant composition measurements of UHECRs, and they report conflicting measurements. The hybrid composition measurement done in this work can be directly compared to the hybrid PAO result.

The transition from the High Resolution Fly's Eye (HiRes) experiment to the Telescope Array (TA) experiment has been completed. The TA Middle Drum fluorescence detector was built using refurbished telescopes from the HiRes-1 site so that a direct comparison could be made between the energy scales of the two experiments. I have made a comparison between the published HiRes spectrum [3] and a preliminary energy spectrum using data collected with the Middle Drum telescopes. Both sets of data represent measurements made via the monocular observation technique and were analyzed using the HiRes-1 profile-constrained geometry reconstruction technique. The HiRes-1 data represents almost nine years of exposure and was collected betweenMay 29, 1997 and May 26, 2006. The Middle Drum data were collected over a three-year period between December 16, 2007 and December 16, 2010. The Middle Drum exposure is about one third of the HiRes-1 total exposure. I have demonstrated that the Middle Drum detector has the same energy scale as HiRes-1. The published HiRes-1 and Middle Drum spectra presented in this dissertation were measured using average calibrations. A study was preformed on the HiRes-1 data to determine the systematic effects of using the nightly atmospheric and electronic-calibration databases instead of average values. The difference between using the average values and using the detailed nightly databases was less than 1%, indicating the spectral results are robust to these differences. Finally, a search was made for the interaction between cosmic rays and ions in the heliosphere. This interaction could result in a unique signature of parallel, simultaneous photon showers. The HiRes-1 data were chosen for this search due to its large exposure and resulting data set. Unfortunately, detector limitations restricted the potential observations. No double-shower events were detected; however, if observed, this would be suggestive of new physics. Monte Carlo simulated events were used to calculate a preliminary aperture of the HiRes-1 detector for these exotic events and future refinements will allow us to set a physical limit on the rate of events. I would like to dedicate this work to my wife, Larissa. Your support through this process has been the island in my stream. I would also like to dedicate this work to my son, Evan, and soon-to-be daughter, Shaye, who came at just the right time to keep me smiling.

Recent progress in the field of ultra-high energy cosmic rays has been driven by the data collected by the Pierre Auger Observatory in the southern hemisphere, and also by the Telescope Array in the northern hemisphere. These hybrid observatories combine large ground arrays with fluorescence detection techniques. In this paper, selected results will be reviewed. Future challenges and prospects will be briefly addressed.