133 research outputs found
Innovative Manufacturing Process for Defect Free, Affordable, High Pressure, Thin Walled, Hydraulic Tubing
Various thermo-mechanical processes were performed on a standard and a low oxygen content Ti-6Al-4V alloy. Testing was performed to determine whether it was possible to achieve a combination of tensile properties comparable to those of Ti-3Al-2.5V by means of cold working and annealing Ti-6Al-4V from a thickness of 0.671 cm (0.264 in.) to that between 0.081 and 0.094 cm (0.032-0.037 in.), which had never been carried out before. The resulting mechanical properties of this study were compared to the mechanical properties of Ti-3Al-2.5V to determine whether Ti-6Al-4V could be used as a suitable replacement for hydraulic tubing applications. The optimum results were achieved with 10-15% cold work and annealing at 750 A degrees C (1382 A degrees F) for 2 h between cold work reductions in thickness. It was concluded that Ti-6Al-4V was a suitable replacement for Ti-3Al-2.5V for hydraulic tubing with an increase in ultimate and yield strengths, but with a slight sacrifice of 5-10% elongation
First results from the AugerPrime Radio Detector
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 km2 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
The Pierre Auger Observatory Open Data
The Pierre Auger Collaboration has embraced the concept of open access to
their research data since its foundation, with the aim of giving access to the
widest possible community. A gradual process of release began as early as 2007
when 1% of the cosmic-ray data was made public, along with 100% of the
space-weather information. In February 2021, a portal was released containing
10% of cosmic-ray data collected from 2004 to 2018, during Phase I of the
Observatory. The Portal included detailed documentation about the detection and
reconstruction procedures, analysis codes that can be easily used and modified
and, additionally, visualization tools. Since then the Portal has been updated
and extended. In 2023, a catalog of the 100 highest-energy cosmic-ray events
examined in depth has been included. A specific section dedicated to
educational use has been developed with the expectation that these data will be
explored by a wide and diverse community including professional and
citizen-scientists, and used for educational and outreach initiatives. This
paper describes the context, the spirit and the technical implementation of the
release of data by the largest cosmic-ray detector ever built, and anticipates
its future developments.Comment: 19 pages, 8 figure
Searches for Ultra-High-Energy Photons at the Pierre Auger Observatory
The Pierre Auger Observatory, being the largest air-shower experiment in the
world, offers an unprecedented exposure to neutral particles at the highest
energies. Since the start of data taking more than 18 years ago, various
searches for ultra-high-energy (UHE, ) photons have
been performed: either for a diffuse flux of UHE photons, for point sources of
UHE photons or for UHE photons associated with transient events like
gravitational wave events. In the present paper, we summarize these searches
and review the current results obtained using the wealth of data collected by
the Pierre Auger Observatory.Comment: Review article accepted for publication in Universe (special issue on
ultra-high energy photons
Radio Measurements of the Depth of Air-Shower Maximum at the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA), part of the Pierre Auger
Observatory, is currently the largest array of radio antenna stations deployed
for the detection of cosmic rays, spanning an area of km with 153
radio stations. It detects the radio emission of extensive air showers produced
by cosmic rays in the MHz band. Here, we report the AERA measurements
of the depth of the shower maximum (), a probe for mass
composition, at cosmic-ray energies between to eV,
which show agreement with earlier measurements with the fluorescence technique
at the Pierre Auger Observatory. We show advancements in the method for radio
reconstruction by comparison to dedicated sets of CORSIKA/CoREAS
air-shower simulations, including steps of reconstruction-bias identification
and correction, which is of particular importance for irregular or sparse radio
arrays. Using the largest set of radio air-shower measurements to date, we show
the radio resolution as a function of energy, reaching a
resolution better than g cm at the highest energies, demonstrating
that radio measurements are competitive with the established
high-precision fluorescence technique. In addition, we developed a procedure
for performing an extensive data-driven study of systematic uncertainties,
including the effects of acceptance bias, reconstruction bias, and the
investigation of possible residual biases. These results have been
cross-checked with air showers measured independently with both the radio and
fluorescence techniques, a setup unique to the Pierre Auger Observatory.Comment: Submitted to Phys. Rev.
Constraining models for the origin of ultra-high-energy cosmic rays with a novel combined analysis of arrival directions, spectrum, and composition data measured at the Pierre Auger Observatory
Ground observations of a space laser for the assessment of its in-orbit performance
The wind mission Aeolus of the European Space Agency was a groundbreaking
achievement for Earth observation. Between 2018 and 2023, the space-borne lidar
instrument ALADIN onboard the Aeolus satellite measured atmospheric wind
profiles with global coverage which contributed to improving the accuracy of
numerical weather prediction. The precision of the wind observations, however,
declined over the course of the mission due to a progressive loss of the
atmospheric backscatter signal. The analysis of the root cause was supported by
the Pierre Auger Observatory in Argentina whose fluorescence detector
registered the ultraviolet laser pulses emitted from the instrument in space,
thereby offering an estimation of the laser energy at the exit of the
instrument for several days in 2019, 2020 and 2021. The reconstruction of the
laser beam not only allowed for an independent assessment of the Aeolus
performance, but also helped to improve the accuracy in the determination of
the laser beam's ground track on single pulse level. The results presented in
this paper set a precedent for the monitoring of space lasers by ground-based
telescopes and open new possibilities for the calibration of cosmic-ray
observatories.Comment: 10 pages, 10 figure
AugerPrime Surface Detector Electronics
Operating since 2004, the Pierre Auger Observatory has led to major advances
in our understanding of the ultra-high-energy cosmic rays. The latest findings
have revealed new insights that led to the upgrade of the Observatory, with the
primary goal of obtaining information on the primary mass of the most energetic
cosmic rays on a shower-by-shower basis. In the framework of the upgrade,
called AugerPrime, the 1660 water-Cherenkov detectors of the surface array are
equipped with plastic scintillators and radio antennas, allowing us to enhance
the composition sensitivity. To accommodate new detectors and to increase
experimental capabilities, the electronics is also upgraded. This includes
better timing with up-to-date GPS receivers, higher sampling frequency,
increased dynamic range, and more powerful local processing of the data. In
this paper, the design characteristics of the new electronics and the enhanced
dynamic range will be described. The manufacturing and test processes will be
outlined and the test results will be discussed. The calibration of the SD
detector and various performance parameters obtained from the analysis of the
first commissioning data will also be presented
Demonstrating Agreement between Radio and Fluorescence Measurements of the Depth of Maximum of Extensive Air Showers at the Pierre Auger Observatory
We show, for the first time, radio measurements of the depth of shower
maximum () of air showers induced by cosmic rays that are
compared to measurements of the established fluorescence method at the same
location. Using measurements at the Pierre Auger Observatory we show full
compatibility between our radio and the previously published fluorescence data
set, and between a subset of air showers observed simultaneously with both
radio and fluorescence techniques, a measurement setup unique to the Pierre
Auger Observatory. Furthermore, we show radio resolution as a
function of energy and demonstrate the ability to make competitive
high-resolution measurements with even a sparse radio array.
With this, we show that the radio technique is capable of cosmic-ray mass
composition studies, both at Auger and at other experiments.Comment: Submitted to Phys. Rev. Let
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