61. AugerNext: R&D studies at the Pierre Auger Observatory for a next generation ground-based ultra-high energy cosmic-ray experimentAndreas Haungs, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The findings so far of the Pierre Auger Observatory and those
of the Telescope Array define some requirements for a possible
next generation global cosmic ray observatory: it needs to be
considerably increased in size, it needs enhanced sensitivity
to composition, and it has to cover the full sky. At the Pierre
Auger Observatory, AugerNext aims to conduct some innovative
initial research studies on a design of a sophisticated hybrid
detector fulfilling these demands. Within a European supported
ASPERA/APPEC (Astroparticle Physics European Consortium)
project for the years 2011-2014, such R&D studies primarily
focused on the following areas: i) consolidation of the
detection of cosmic rays using MHz radio antennas; ii) proof-
of-principle of cosmic ray microwave detection; iii) test of
the large-scale application of new generation photo sensors;
iv) generalization of data communication techniques; and v)
development of new schemes for muon detection with surface
arrays. The AugerNext Consortium consists of 14 principal
investigators from 9 countries. This contribution summarizes
some achievements of the R&D studies within the AugerNext
project. Ključne besede: ultra-high energy cosmic-ray experiments, Pierre Auger Observatory, Telescope Array, AugerNext research and development study Objavljeno v RUNG: 03.03.2016; Ogledov: 5029; Prenosov: 198
Celotno besedilo (594,23 KB) |
62. Status and Prospects of the Auger Engineering Radio ArrayJohannes Schulz, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The Auger Engineering Radio Array (AERA) is an extension of the
Pierre Auger Observatory. It is used to detect radio emission
from extensive air showers in the 30 - 80 MHz frequency band.
A focus of interest is the dependence of the radio emission on
shower parameters such as the energy and the atmospheric depth
of the shower maximum. After three phases of deployment, AERA
now consists of 153 autonomous radio stations with different
spacings, covering an area of about 17 km2. The size, station
spacings, and geographic location at the same site or near other
Auger extensions, are all targeted at cosmic ray energies above
10[sup]17 eV. The array allows us to explore different
technical schemes to measure the radio emission as well as to
cross calibrate our measurements with the established baseline
detectors of the Auger Observatory. We present the most recent
technological developments and selected experimental results
obtained with AERA. Ključne besede: Pierre Auger Observatory, the Auger Engineering Radio Array (AERA), radio emission from extensive air showers, detector cross-calibration Objavljeno v RUNG: 03.03.2016; Ogledov: 4653; Prenosov: 196
Celotno besedilo (2,79 MB) |
63. Automated procedures for the Fluorescence Detector calibration at the Pierre Auger ObservatoryGaetano Salina, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The quality of the physics results, derived from the analysis
of the data collected at the Pierre Auger Observatory depends
heavily on the calibration and monitoring of the components of
the detectors. It is crucial to maintain a database containing complete information on the absolute calibration of all
photomultipliers and their time evolution. The low rate of the
physics events implies that the analysis will have to be made
over a long period of operation. This requirement imposes a
very organized and reliable data storage and data management
strategy, in order to guarantee correct data preservation and
high data quality. The Fluorescence Detector (FD) consists of
27 telescopes with about 12,000 phototubes which have to be
calibrated periodically. A special absolute calibration system
is used. It is based on a calibrated light source with a
diffusive screen, uniformly illuminating photomultipliers
of the camera. This absolute calibration is performed every few
years, as its use is not compatible with the operation of the
detector. To monitor the stability and the time behavior,
another light source system operates every night of data
taking. This relative calibration procedure yields more than
2×10[sup]4 raw files each year, about 1 TByte/year. In this
paper we describe a new web-interfaced database architecture
to manage, store, produce and analyse FD calibration data.
It contains the configuration and operating parameters of the
detectors at each instant and other relevant functional
parameters that are needed for the analysis or to monitor
possible instabilities, used for the early discovery of
malfunctioning components. Based on over 10 years of
operation, we present results on the long term performance
of FD and its dependence on environmental variables. We also
report on a check of the absolute calibration values by
analysing the signals left by stars traversing the FD field of
view. Ključne besede: Pierre Auger Observatory, Fluorescence Detector, detector calibration and monitoring, automated calibration procedure Objavljeno v RUNG: 03.03.2016; Ogledov: 4386; Prenosov: 202
Celotno besedilo (1,06 MB) |
64. Measurement of the water-Cherenkov detector response to inclined muons using an RPC hodoscopePedro Assis, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The Pierre Auger Observatory operates a hybrid detector
composed of a Fluorescence Detector and a Surface Detector
array. Water-Cherenkov detectors (WCD) are the building blocks
of the array and as such play a key role in the detection of
secondary particles at the ground. A good knowledge of the
detector response is of paramount importance to lower
systematic uncertainties and thus to increase the capability
of the experiment in determining the muon content of the
extensive air showers with a higher precision.
In this work we report on a detailed study of the detector
response to single muons as a function of their trajectories
in the WCD. A dedicated Resistive Plate Chambers (RPC)
hodoscope was built and installed around one of the detectors.
The hodoscope is formed by two stand-alone low gas flux
segmented RPC detectors with the test water-Cherenkov detector
placed in between. The segmentation of the RPC detectors is of
the order of 10 cm. The hodoscope is used to trigger and
select single muon events in different geometries. The signal
recorded in the water-Cherenkov detector and performance
estimators were studied as a function of the trajectories of
the muons and compared with a dedicated simulation.
An agreement at the percent level was found, showing that the
simulation correctly describes the tank response. Ključne besede: Pierre Auger Observatory, Water-Cherenkov detectors, detector calibration, inclined cosmic ray muons, Resistive Plate Chambers (RPC) hodoscope Objavljeno v RUNG: 03.03.2016; Ogledov: 4778; Prenosov: 198
Celotno besedilo (1,27 MB) |
65. The Energy Content of Extensive Air Showers in the Radio Frequency Range of 30-80 MHzChristian Glaser, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: At the Auger Engineering Radio Array (AERA) of the Pierre Auger
Observatory, we have developed a new method to measure the
total amount of energy that is transferred from the primary
cosmic ray into radio emission. We find that this radiation
energy is an estimator of the cosmic ray energy. It scales
quadratically with the cosmic ray energy, as expected for
coherent emission. We measure 15.8 MeV of radiation energy for
a 1 EeV air shower arriving perpendicular to the geomagnetic
field at the Auger site, in the frequency band of the detector
from 30 to 80 MHz. These observations are compared to the data
of the surface detector of the Observatory, which provide
well-calibrated energies and arrival directions of the cosmic
rays. We find energy resolutions of the radio reconstruction
of 22% for the complete data set, and 17% for a high-quality
subset containing only events with at least five stations with
signal. Ključne besede: Pierre Auger Observatory, the Auger Engineering Radio Array (AERA), extensive air showers, radio reconstruction: energy resolution Objavljeno v RUNG: 03.03.2016; Ogledov: 4774; Prenosov: 210
Celotno besedilo (574,66 KB) |
66. The AMIGA Muon Counters of the Pierre Auger Observatory: Performance and Studies of the Lateral Distribution FunctionBrian Wundheiler, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The AMIGA enhancement (Auger Muons and Infill for the Ground
Array) of the Pierre Auger Observatory consists of a 23.5 km2
infill area where air shower particles are sampled by water-
Cherenkov detectors at the surface and by 30 m2 scintillation
counters buried 2.3 m underground. The Engineering Array of
AMIGA, completed since February 2015, includes 37 scintillator
modules (290 m2) in a hexagonal layout. In this work, the muon
counting performance of the scintillation detectors is analysed
over the first 20 months of operation. Parametrisations of the
detector counting resolution and the lateral trigger
probability are presented. Finally, preliminary results on the observed muon lateral distribution function (LDF) are discussed. Ključne besede: Pierre Auger Observatory, AMIGA (Auger Muons and Infill for the Ground Array) muon
counters, muon lateral distribution function (LDF) Objavljeno v RUNG: 03.03.2016; Ogledov: 4218; Prenosov: 178
Celotno besedilo (499,33 KB) |
67. Upgrade of the Pierre Auger Observatory (AugerPrime)Ralph Engel, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The data collected with the Pierre Auger Observatory have led
to a number of surprising discoveries. While a strong
suppression of the particle flux at the highest energies has
been established unambiguously, the dominant physics processes
related to this suppression could not be identified.
Within the energy range covered by fluorescence detector
observations with sufficient statistics, an unexpected change
of the depth of maximum distribution is found. Using LHC-tuned
interaction models these observations can be understood as a
correlated change of the fluxes of different mass groups.
On the other hand, they could also indicate a change of
hadronic interactions above the energy of the ankle.
Complementing the water Cherenkov detectors of the surface
array with scintillator detectors will, mainly through the
determination of the muonic shower component, extend the
composition sensitivity of the Auger Observatory into the flux
suppression region. The upgrade of the Auger Observatory will
allow us to estimate the primary mass of the highest energy
cosmic rays on a shower-by-shower basis. In addition to
measuring the mass composition the upgrade will open the
possibility to search for light primaries at the highest
energies, to perform composition-selected anisotropy studies,
and to search for new phenomena including unexpected changes
of hadronic interactions. After introducing the physics
motivation for upgrading the Auger Observatory the planned
detector upgrade is presented. In the second part
of the contribution the expected performance and improved
physics sensitivity of the upgraded Auger Observatory are
discussed. Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays, elemental composition sensitivity, Auger upgrade (AugerPrime), muonic shower component, scintillator detectors Objavljeno v RUNG: 03.03.2016; Ogledov: 4429; Prenosov: 222
Celotno besedilo (659,02 KB) |
68. Studies in the atmospheric monitoring at the Pierre Auger Observatory using the upgraded Central Laser FacilityCarlos Medina-Hernandez, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The Fluorescence Detector (FD) at the Pierre Auger Observatory
measures the intensity of the scattered light from laser tracks
generated by the Central Laser Facility (CLF) and the eXtreme
Laser Facility (XLF) to monitor and estimate the vertical
aerosol optical depth (τ(z,t)). This measurement is needed to
obtain unbiased and reliable FD measurements of the arrival
direction and energy of the primary cosmic ray, and the depth
of the maximum shower development. The CLF was upgraded
substantially in 2013 with the addition of a solid state laser,
new generation GPS, a robotic beam calibration system, better
thermal and dust isolation, and improved software. The upgrade
also included a back-scatter Raman LIDAR to measure τ(z,t).
The new features and applications of the upgraded instrument
are described. These include the laser energy calibration
and the atmospheric monitoring measurements. The first τ(z,t)
results and comparisons after the upgrade are presented using different methods. The first method compares the FD hourly
response to the scattered light from the CLF (or XLF) against
a reference hourly profile measured during a clear night where
zero aerosol contents are assumed. The second method simulates
FD responses with different atmospheric parameters and selects the parameters that provide the best fit to the actual FD
response. A third method uses the new Raman LIDAR receiver
in-situ to measure the back-scatter light from the CLF laser.
The results show a good data agreement for the first and second
methods using FD stations located at the same distance from the
facilities. Preliminary results of τ(z,t) using the Raman LIDAR
are presented as well. Ključne besede: Pierre Auger Observatory, extensive air showers, the Fluorescence Detector, atmospheric monitoring, vertical aerosol optical depth, the Central Laser Facility, the eXtreme Laser Facility Objavljeno v RUNG: 03.03.2016; Ogledov: 4959; Prenosov: 182
Celotno besedilo (3,96 MB) |
69. Lightning Detection at the Pierre Auger ObservatoryJulian Rautenberg, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The Auger Engineering Radio Array, an extension of the Pierre
Auger Observatory with antennas in the MHz range, requires to
monitor the atmospheric conditions, which have a large influence
on the radio emission of air showers. In particular, amplified
signals up to an order of magnitude have been detected as an
affect of thunderstorms. For a more detailed investigation and
more generally, for detecting thunderstorms, a new lightning
detection system has been installed at the Pierre Auger
Observatory in Argentina. In addition, an electric-field mill
measures the field strength on ground level at the antenna
array. With these measurements, data periods affected
by thunderstorms can be identified. Additionally, a lightning
trigger for the water-Cherenkov detectors was developed to read
out individual stations when a lightning was detected nearby.
With these data, a possible correlation between the formation
of lightning and cosmic rays can be investigated even at low
energies of about 10[sup]15 eV. The structure and functionality
of the lightning detection are described and first data
analyses are shown. Ključne besede: Pierre Auger Observatory, Auger Engineering Radio Array, atmospheric monitoring, lightning detectors Objavljeno v RUNG: 03.03.2016; Ogledov: 4553; Prenosov: 198
Celotno besedilo (1,10 MB) |
70. Solar Cycle Modulation of Cosmic Rays Observed with the Low Energy Modes of the Pierre Auger ObservatoryJimmy Masías-Meza, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The low energy modes of the surface detector array of the
Pierre Auger Observatory record variations in the flux of low
energy secondary particles with extreme detail. These two modes
consist of recording (1) the rate of signals for energies
between ∼15 MeV and ∼100 MeV (the Scaler mode) and (2) the
calibration charge histograms of the individual pulses detected
by each water-Cherenkov station, covering different energy
channels up to ∼1 GeV (the Histogram mode). Previous work has
studied the flux of galactic cosmic rays on short and
intermediate time scales (i.e. from minutes to weeks) using
these low energy modes. In this work, after including a long-
term correction to the response of the detectors, we present
the first long-term analysis of the flux of cosmic rays using
scalers and two energy bands of the calibration histograms.
We show its sensitivity to the solar cycle variation and its
relation to the solar modulation of cosmic rays for an 8-year
period. Ključne besede: Pierre Auger Observatory, Surface Detector, secondary cosmic rays, scaler mode, charge histogram mode, solar cycle modulation Objavljeno v RUNG: 03.03.2016; Ogledov: 4913; Prenosov: 203
Celotno besedilo (533,18 KB) |