The offline software framework of the Pierre Auger Observatory Argirò, S.; Barroso, S.L.C.; Gonzalez, J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2007, Letnik:
580, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The Pierre Auger Observatory is designed to unveil the nature and the origins of the highest energy cosmic rays. The large and geographically dispersed collaboration of physicists and the ...wide-ranging collection of simulation and reconstruction tasks pose some special challenges for the offline analysis software. We have designed and implemented a general purpose framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. The framework includes machinery to manage these user codes, to organize the abundance of user-contributed configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information which can reside in various data sources. A number of utilities are also provided, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice. The framework is implemented in
C
++
, and takes advantage of object oriented design and common open source tools, while keeping the user side simple enough for
C
++
novices to learn in a reasonable time. The distribution system incorporates unit and acceptance testing in order to support rapid development of both the core framework and contributed user code.
Measurements of hadron production in p + C interactions at 31 GeV/
c
are performed using the NA61/SHINE spectrometer at the CERN SPS. The analysis is based on the full set of data collected in 2009 ...using a graphite target with a thickness of 4 % of a nuclear interaction length. Inelastic and production cross sections as well as spectra of
π
±
,
K
±
, p,
K
S
0
and
Λ
are measured with high precision. These measurements are essential for improved calculations of the initial neutrino fluxes in the T2K long-baseline neutrino oscillation experiment in Japan. A comparison of the NA61/SHINE measurements with predictions of several hadroproduction models is presented.
The present white paper is submitted as part of the “Snowmass” process to help inform the long-term plans of the United States Department of Energy and the National Science Foundation for high-energy ...physics. It summarizes the science questions driving the Ultra-High-Energy Cosmic-Ray (UHECR) community and provides recommendations on the strategy to answer them in the next two decades.
To improve the detection range and signal to noise ratio in the remote sensing of atmospheric processes using long-range scanning Mie lidar, simultaneously obtained analog (A) and photon-counting (P) ...data traces were merged using a novel gluing method based on the modification of the A trace so that it follows Poisson statistics. In comparison with the traditional method based on the minimization of the distance between A and P, the advantage of this new approach is an improved uniformity of the merged data trace as well as a reduced influence of atmospheric conditions on the obtained transfer coefficients. The atmospheric extinction was subsequently retrieved using the two- and multi-angle method. The offset of the laser beam direction was calibrated against a self-leveling laser, as an offset in elevation angle was found to produce considerable error in the atmospheric extinction profiles obtained under the assumption of horizontal atmospheric homogeneity.
► Characteristics of analog and PC data trace were evaluated by variance calculation. ► PC data trace is Poissonian distributed, while analog data trace is linear shifted. ► Novel gluing method by modifying analog data to follow Poissonian was investigated. ► Lidar elevation angle was horizontally calibrated against a self-leveling laser. ► Small angular offset was found to have a visible impact on atmospheric extinction.
A measuring campaign was performed over the neighboring towns of Nova Gorica in Slovenia and Gorizia in Italy on 24 and 25 May 2010, to investigate the concentration and distribution of urban ...aerosols. Tracking of two-dimensional spatial and temporal aerosol distributions was performed using scanning elastic LIDAR, operating at 1064 nm. In addition, PM10 concentrations of particles, NOx concentrations and meteorological data were continuously monitored within the LIDAR scanning region. Based on the data we collected, we investigated the flow dynamics and the aerosol concentrations within the lower troposphere and found an evidence for daily aerosol cycles. We observed a number of cases with spatially localized increased LIDAR returns, which are associated with the presence of point sources of particulate matter. Daily aerosol concentration cycles were also clearly visible with a peak in aerosol concentration during the morning rush hours and daily plateau at around 17:00 Central European Time. We also found that horizontal atmospheric extinction at the height of 200 m, averaged in limited region with a radius of 300 m directly above the ground-based measuring site, was linearly correlated to the PM10 concentration with a correlation coefficient of 0.84. When considering the average of the horizontal atmospheric extinction over the entire scanning region, a strong dependence on traffic conditions (concentration of NOx) in the vicinity of the ground-based measuring site was observed.
Optical properties of the atmospheric boundary layer (ABL) above the land–sea transition interface were measured using a scanning Mie lidar located 30
km away from the Adriatic coast. Based on the ...two-dimensional range-height-indicator scans, detailed information on the ABL was obtained, including parameters such as atmospheric optical depth, aerosol extinction coefficient and the height of the ABL. The presented case study indicates that the height of the ABL in the land–sea transition zone and the adjacent mountainous region was changing rapidly due to highly variable atmospheric conditions.
The eruption of the Eyjafjallajökull volcano starting on 14 April 2010 resulted in the spreading of volcanic ash over most parts of Europe. In Slovenia, the presence of volcanic ash was monitored ...using ground-based in-situ measurements, lidar-based remote sensing and airborne in-situ measurements. Volcanic origin of the detected aerosols was confirmed by subsequent spectral and chemical analysis of the collected samples. The initial arrival of volcanic ash to Slovenia was first detected through the analysis of precipitation, which occurred on 17 April 2010 at 01:00 UTC and confirmed by satellite-based remote sensing. At this time, the presence of low clouds and occasional precipitation prevented ash monitoring using lidar-based remote sensing. The second arrival of volcanic ash on 20 April 2010 was detected by both lidar-based remote sensing and airborne in-situ measurements, revealing two or more elevated atmospheric aerosol layers. The ash was not seen in satellite images due to lower concentrations. The identification of aerosol samples from ground-based and airborne in-situ measurements based on energy-dispersive X-ray spectroscopy confirmed that a fraction of particles were volcanic ash from the Eyjafjallajökull eruption. To explain the history of the air masses bringing volcanic ash to Slovenia, we analyzed airflow trajectories using ECMWF and HYSPLIT models.
The Lidar system of the Pierre Auger Observatory BenZvi, S.Y.; Cester, R.; Chiosso, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2007, Letnik:
574, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Pierre Auger Observatory in Malargüe, Argentina, is designed to study the origin of ultrahigh energy cosmic rays with energies above
10
18
eV
. The energy calibration of the detector is based on ...a system of four air fluorescence detectors. To obtain reliable calorimetric information from the fluorescence stations, the atmospheric conditions at the experiment's site need to be monitored continuously during operation. One of the components of the observatory's atmospheric monitoring system is a set of four elastic backscatter lidar stations, one station at each of the fluorescence detector sites. This paper describes the design, current status, standard operation procedure, and performance of the lidar system of the Pierre Auger Observatory.
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