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
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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.
Characterisation of scCVD diamond detectors with γ sources Caiffi, B.; Amapane, N.; Argirò, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2014, Letnik:
754
Journal Article
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A single-crystal CVD (Chemical Vapor Deposition) diamond detector was used to measure γ rays in order to assess its performance in terms of energy resolution and linearity. For this purpose, 57Co, ...133Ba, 22Na, 207Bi and 137Cs γ sources were used. Electrons scattered by the backward Compton process were detected in the diamond, in coincidence with (backscattered) γs measured in a NaI detector, placed at 180° from the CVD diamond detector with respect to the source. The resulting calibration shows a linear dependence of the charge deposited in the diamond and a resolution of about 24keV FWHM for the energy of the incident γs between 40keV (57Co) and 477keV (137Cs), comparable with the resolution of our electronic chain.
In 2012, 14 Italian Institutions participating LHC Experiments (10 in CMS) have won a grant from the Italian Ministry of Research (MIUR), to optimize Analysis activities and in general the ...Tier2/Tier3 infrastructure. A large range of activities is actively carried on: they cover data distribution over WAN, dynamic provisioning for both scheduled and interactive processing, design and development of tools for distributed data analysis, and tests on the porting of CMS software stack to new highly performing / low power architectures.
In 2012, 14 Italian institutions participating in LHC Experiments won a grant from the Italian Ministry of Research (MIUR), with the aim of optimising analysis activities, and in general the Tier2 ...Tier3 infrastructure. We report on the activities being researched upon, on the considerable improvement in the ease of access to resources by physicists, also those with no specific computing interests. We focused on items like distributed storage federations, access to batch-like facilities, provisioning of user interfaces on demand and cloud systems. R&D on next-generation databases, distributed analysis interfaces, and new computing architectures was also carried on. The project, ending in the first months of 2016, will produce a white paper with recommendations on best practices for data-analysis support by computing centers.
An Xrootd Italian Federation Boccali, T; Donvito, G; Diacono, D ...
Journal of physics. Conference series,
01/2014, Letnik:
513, Številka:
4
Journal Article
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The Italian community in CMS has built a geographically distributed network in which all the data stored in the Italian region are available to all the users for their everyday work. This activity ...involves at different level all the CMS centers: the Tier1 at CNAF, all the four Tier2s (Bari, Rome, Legnaro and Pisa), and few Tier3s (Trieste, Perugia, Torino, Catania, Napoli, ...). The federation uses the new network connections as provided by GARR, our NREN (National Research and Education Network), which provides a minimum of 10 Gbit/s to all the sites via the GARR-X2 project. The federation is currently based on Xrootd1 technology, and on a Redirector aimed to seamlessly connect all the sites, giving the logical view of a single entity. A special configuration has been put in place for the Tier1, CNAF, where ad-hoc Xrootd changes have been implemented in order to protect the tape system from excessive stress, by not allowing WAN connections to access tape only files, on a file-by-file basis. In order to improve the overall performance while reading files, both in terms of bandwidth and latency, a hierarchy of xrootd redirectors has been implemented. The solution implemented provides a dedicated Redirector where all the INFN sites are registered, without considering their status (T1, T2, or T3 sites). An interesting use case were able to cover via the federation are disk-less Tier3s. The caching solution allows to operate a local storage with minimal human intervention: transfers are automatically done on a single file basis, and the cache is maintained operational by automatic removal of old files.
Neutron spectrometer for fast nuclear reactors Osipenko, M.; Ripani, M.; Ricco, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2015, Letnik:
799
Journal Article
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In this paper we describe the development and first tests of a neutron spectrometer designed for high flux environments, such as the ones found in fast nuclear reactors. The spectrometer is based on ...the conversion of neutrons impinging on 6Li into α and t whose total energy comprises the initial neutron energy and the reaction Q-value. The 6LiF layer is sandwiched between two CVD diamond detectors, which measure the two reaction products in coincidence. The spectrometer was calibrated at two neutron energies in well known thermal and 3MeV neutron fluxes. The measured neutron detection efficiency varies from 4.2×10−4 to 3.5×10−8 for thermal and 3MeV neutrons, respectively. These values are in agreement with Geant4 simulations and close to simple estimates based on the knowledge of the 6Li(n,α)t cross-section. The energy resolution of the spectrometer was found to be better than 100keV when using 2.5 or 5m cables between the detector and the preamplifiers.
Monitoring DC anode current of a grounded-cathode photomultiplier tube Argirò, S; Camin, D.V; Destro, M ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/1999, Letnik:
435, Številka:
3
Journal Article
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The Pierre Auger Observatories (PAO) for the highest energy cosmic rays will make use of both the Cherenkov and Air Fluorescence techniques. Surface Detectors (SD) and Fluorescence Detectors (FD) ...will have to operate in a desert-type environment during at least 15 years. In order to avoid dust deposition, due to electrostatics, and other practical inconveniences derived from biasing the cathode with a negative potential, the 15
000 PMTs of the FD will operate in the grounded cathode configuration. Despite the fact that the anodes will remain at high voltage with respect to ground, the DC anode current, which varies with background light, will have to be recorded. We have developed a current monitoring system based on a novel optocoupled feedback circuit that allows sensitive, linear, and temperature-independent measurements of the DC anode current. A distinctive feature of this circuit is that it uses optical coupling between passive components at high voltage and active components near the ground potential. This represents a substantial improvement over classical solutions which require the supply of power to an active circuit at high voltage. We report on the first tests performed with both active and passive biasing networks which demonstrate the validity of this new method.
Experiment E835 at Fermilab Garzoglio, G.; Gollwitzer, K.; Hahn, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2004, Letnik:
519, Številka:
3
Journal Article
Recenzirano
We provide a comprehensive description of experiment E835 at Fermilab, a high-precision experimental study of charmonium bound states. The
c
̄
c
states are formed in
p
̄
p
annihilations of cooled ...antiprotons stored in the Fermilab Antiproton Accumulator using a dense internal hydrogen gas-jet target. We describe the experimental strategies adopted for detecting the tiny
c
̄
c
resonant signals in the huge non-resonant hadronic background, and for measuring resonance parameters with high precision.
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