Abstract
Operating since 2004, the Pierre Auger Observatory has yielded several important results. The suppression of the flux around 5×10
19
eV is now confirmed without any doubt, a large-scale ...dipole anisotropy has been found for energies above 8×10
18
eV, as well as an indication for some intermediate-scale anisotropy at the highest energies. Furthermore, strong limits have been placed on ultra-high-energy photons and neutrinos. In order to elucidate the origin of the flux suppression at the highest energies and search for composition-enhanced anisotropies, the Auger Collaboration is currently upgrading the Observatory. In the framework of the upgrade, called AugerPrime, the array of 1660 water-Cherenkov detectors is equipped with plastic scintillators, allowing us to enhance the composition sensitivity. The station electronics is also upgraded, including better timing with up-to-date GPS receivers, higher sampling frequency, and increased dynamic range. Currently, more than 40% of the surface detectors have been upgraded, and the commissioning studies are well advanced. In this paper, the design of the AugerPrime surface detectors will be presented, and the performance obtained from the analysis of the first data will be discussed.
Recent microscopic and phenomenological calculations of giant dipole resonances for
A
⩽
56 nuclei are presented. The derived photodisintegration cross sections are exhaustively compared to the ...photonuclear data available to date. An accurate description of the data is found. Our new calculations are also compared with the previous and widely-used estimates of Puget, Stecker and Bredekamp. The present calculations also include all the possible paths down the nuclear chart. The impact on the photodisintegration of ultra-high-energy cosmic rays (UHECR) is illustrated for a Fe source with typical energies of 10
20–10
21
eV. At energies around 10
20
eV, the new cross sections are found to modify the UHECR photodisintegration rates. At energies around 10
21
eV, it is recommended to solve a full reaction network to estimate the photodisintegration rate of the UHECR.
MUST: A silicon strip detector array for radioactive beam experiments Blumenfeld, Y; Auger, F; Sauvestre, J.E ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/1999, Letnik:
421, Številka:
3
Journal Article
Recenzirano
A new and innovative array, MUST, based on silicon strip technology and dedicated to the study of reactions induced by radioactive beams on light particles is described. The detector consists of 8 ...silicon strip – Si(Li) telescopes used to identify recoiling light charged particles through time of flight, energy loss and energy measurements and to determine precisely their scattering angle through
X,
Y
position measurements. Each 60×60
mm
2 double sided silicon strip detector with 60 vertical and 60 horizontal strips yields an
X–
Y position resolution of 1
mm, an energy resolution of 50
keV, a time resolution of around 1
ns and a 500
keV energy threshold for protons. The backing Si(Li) detectors stop protons up to 25
MeV with a resolution of approximately 50
keV. CsI crystals read out by photo-diodes which stop protons up to 70
MeV are added to the telescopes for applications where higher energy particles need to be detected. The dedicated electronics in VXIbus standard allow us to house the 968 logic and analog channels of the array in one crate placed adjacent to the reaction chamber and fully remote controlled, including pulse visualization on oscilloscopes. A stand alone data acquisition system devoted to the MUST array has been developed. Isotope identification of light charged particles over the full energy range has been achieved, and the capability of the system to measure angular distributions of states populated in inverse kinematics reactions has been demonstrated.
The Northern site of the Pierre Auger Observatory Suomijärvi, T.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
To increase statistics for cosmic ray events with energies above 50EeV and to obtained a full sky coverage, a Northern Auger Observatory with a surface of 20,000km2 is planned in South East Colorado, ...USA. The design will use the well proven hybrid concept: a surface array combined with fluorescence telescopes. In this paper, the basic elements of Auger North will be described.
The 10,11Be(p, p) and (12C, 12C) reactions were analyzed to determine the influence of the weak binding energies of exotic nuclei on their interaction potential. The elastic cross sections were ...measured at GANIL in inverse kinematics using radioactive 10,11Be beams produced at energies of 39.1A and 38.4A MeV. The elastic proton scattering data were analyzed within the framework of the microscopic Jeukenne–Lejeune–Mahaux (JLM) nucleon–nucleus potential. The angular distributions are found to be best reproduced by reducing the real part of the microscopic optical potential, as a consequence of the coupling to the continuum. These effects modify deeply the elastic potential. Including the Virtual Coupling Potential (VCP), we show the ability of the general optical potentials to reproduce the data for scattering of unstable nuclei, using realistic densities. Finally, the concepts needed to develop a more general and microscopic approach of the VCP are discussed.
Calibration of the surface array of the Pierre Auger Observatory Bertou, X.; Allison, P.S.; Bonifazi, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2006, Letnik:
568, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The Pierre Auger Observatory is designed to study cosmic rays of the highest energies
(
>
10
19
eV
)
. The ground array of the Observatory will consist of 1600 water Cherenkov detectors deployed over
...3000
km
2
. The remoteness and large number of detectors require a robust, automatic self-calibration procedure. It relies on the measurement of the average charge collected by a photomultiplier tube from the Cherenkov light produced by a vertical and central through-going muon, determined to 5–10% at the detector via a novel rate-based technique and to 3% precision through analysis of histograms of the charge distribution. The parameters needed for the calibration are measured every minute, allowing for an accurate determination of the signals recorded from extensive air showers produced by primary cosmic rays. The method also enables stable and uniform triggering conditions to be achieved.
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