Search the repository

A+ | A- | | SLO | ENG

Keywords: radio measurement, kozmični žarki ekstremnih energij, observatory Pierre Auger
Published in RUNG: 31.01.2024; Views: 374; Downloads: 2
Full text (444,66 KB)

Abstract: A new radio interferometric technique was recently developed that takes into account time lags caused by the three-dimensional dependency of the refractive index in the atmosphere. It enables us to track the extensive air shower while it propagates through the atmosphere. Using this technique, properties of the air shower can be estimated, like the depth of maximum and the axis of propagation. In order to apply this method, strict constraints on the time-synchronisation between radio antennas in an array must be satisfied. In this contribution, we show that the Auger Engineering Radio Array can meet these timing criteria by operating a time reference beacon. We will show how this enables us to reconstruct air shower properties using the radio interferometric technique.
Keywords: ultra-high energy cosmic rays, Pierre Auger Observatory, Auger engineering radio array, radio interferometry
Published in RUNG: 23.01.2024; Views: 368; Downloads: 4
Full text (1,46 MB)
This document has many files! More...

Abstract: The Auger Engineering Radio Array (AERA), part of the Pierre Auger Observatory, is currently the largest facility to measure radio emissions from ultra-high energy extensive air showers. It comprises 153 autonomous radio-detector stations, covering an area of 17 km^2, and measures radio waves in the frequency range from 30 to 80 MHz. An accurate description of the detector response is necessary to interpret the data collected by the stations correctly. Previously, this was achieved by measuring the analog chain in the laboratory and simulating and measuring the directional response of the antenna. In this work, we perform an absolute calibration using the continuously monitored sidereal modulation of the diffuse Galactic radio emission. The calibration is performed by comparing the average spectra recorded by the stations with a model of the full radio sky propagated through the system response, including the antenna, filters, and amplifiers. We describe the method to determine the calibration constants for each antenna and present the corresponding results. Furthermore, the behavior of the calibration constants is studied as a function of time. There is no relevant aging effect over a timescale of a decade, which shows that radio detectors could help monitor possible aging effects of other detector systems during long-term operations, stressing their importance in determining an absolute energy scale.
Keywords: pierre auger observatory, auger engineering radio array, ultra-high energy cosmic rays, radio detectors
Published in RUNG: 22.01.2024; Views: 435; Downloads: 6
Full text (1,03 MB)
This document has many files! More...

Abstract: The Pierre Auger Observatory, located near Malargüe, Argentina, is the world’s largest cosmic-ray detector. It comprises a 3000 km^2 surface detector and 27 fluorescence telescopes, which measure the lateral and longitudinal distributions of the many millions of air-shower particles produced in the interactions initiated by a cosmic ray in the Earth’s atmosphere. The determination of the nature of cosmic rays and studies of the detector performances rely on extensive Monte Carlo simulations describing the physics processes occurring in extensive air showers and the detector responses. The aim of the Monte Carlo simulations task is to produce and provide the Auger Collaboration with reference libraries used in a wide variety of analyses. All multipurpose detector simulations are currently produced in local clusters using Slurm and HTCondor. The bulk of the shower simulations are produced on the grid, via the Virtual Organization auger, using the DIRAC middleware. The job submission is made via python scripts using the DIRAC-API. The Auger site is undergoing a major upgrade, which includes the installation of new types of detectors, demanding increased simulation resources. The novel detection of the radio component of extensive air showers is the most challenging endeavor, requiring dedicated shower simulations with very long computation times, not optimized for the grid production. For data redundancy, the simulations are stored on the Lyon server and the grid Disk Pool Manager and are accessible to the Auger members via iRODS and DIRAC, respectively. The CERN VMFile System is used for software distribution where, soon, the Auger Offline software will also be made available.
Keywords: Pierre Auger Observatory, indirect detection, fluorescence detection, surface detection, radio detection, ultra-high energy, cosmic rays, Monte Carlo simulation, computing resources, compute clusters, high capacity storage
Published in RUNG: 04.10.2023; Views: 644; Downloads: 7
Full text (1,54 MB)
This document has many files! More...

Abstract: The Pierre Auger Observatory investigates the properties of the highest-energy cosmic rays with unprecedented precision. The aim of the AugerPrime upgrade is to improve the sensitivity to the primary particle type. The improved mass sensitivity is the key to exploring the origin of the highest-energy particles in the Universe. The purpose of the Radio Detector (as part of AugerPrime) is to extend the sensitivity of the mass measurements to zenith angles in the range from 65° to 85°. A radio antenna, sensitive in two polarization directions and covering a bandwidth from 30 to 80 MHz, will be added to each of the 1661 surface detector stations over the full 3000 km^2 area, forming the world’s largest radio array for the detection of cosmic particles. Since November 2019, an engineering array comprised of ten stations has been installed in the field. The radio antennas are calibrated using the Galactic (diffuse) emission. The sidereal modulation of this signal is monitored continuously and is used to obtain an end-to-end calibration from the receiving antenna to the ADC in the read-out electronics. The calibration method and first results will be presented. The engineering array is also fully integrated in the data acquisition of the Observatory and records air showers regularly. The first air showers detected simultaneously with the water-Cherenkov detectors and the Radio Detectors will be presented. Simulations of the detected showers, based on the reconstructed quantities, have been conducted with CORSIKA/CoREAS. A comparison of the measured radio signals with those predicted by simulations exhibits satisfying agreement.
Keywords: Pierre Auger Observatory, AugerPrime, indirect detection, radio detection, radio antenna array, surface detection, ground array, ultra-high energy, cosmic rays, galactic radio emission
Published in RUNG: 04.10.2023; Views: 594; Downloads: 6
Full text (1,62 MB)
This document has many files! More...