61. 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, published scientific conference contribution Abstract: 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.
Keywords: Pierre Auger Observatory, Fluorescence Detector, detector calibration and monitoring, automated calibration procedure
Published in RUNG: 03.03.2016; Views: 5337; Downloads: 213
 Full text (1,06 MB) |
62. 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, published scientific conference contribution Abstract: 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.
Keywords: Pierre Auger Observatory, extensive air showers, the Fluorescence Detector, atmospheric monitoring, vertical aerosol optical depth, the Central Laser Facility, the eXtreme Laser Facility
Published in RUNG: 03.03.2016; Views: 6096; Downloads: 184
Full text (3,96 MB) |
