The automated multi-platform software nightly build system is a major component in the ATLAS collaborative software organization, validation and code approval schemes. Code developers from ATLAS ...participating Institutes spread all around the world use about 30 branches of nightly releases for testing new packages, verification of patches to existing software, and migration to new platforms and compilers. The nightly releases lead up to, and are the basis of, stable software releases used for data processing worldwide. The ATLAS nightly builds are managed by the fully automated NICOS framework on the computing farm with 44 powerful multiprocessor nodes. The ATN test tool is embedded within the nightly system and provides results shortly after full compilations complete. Other test frameworks are synchronized with NICOS jobs and run larger scale validation jobs using the nightly releases. NICOS web pages dynamically provide information about the progress and results of the builds. For faster feedback, e-mail notifications about nightly releases problems are automatically distributed to the developers responsible.
The ATLAS experiment deployed Frontier technology worldwide during the initial year of LHC collision data taking to enable user analysis jobs running on the Worldwide LHC Computing Grid to access ...database resident data. Since that time, the deployment model has evolved to optimize resources, improve performance, and streamline maintenance of Frontier and related infrastructure. In this presentation we focus on the specific changes in the deployment and improvements undertaken, such as the optimization of cache and launchpad location, the use of RPMs for more uniform deployment of underlying Frontier related components, improvements in monitoring, optimization of fail-over, and an increasing use of a centrally managed database containing site specific information (for configuration of services and monitoring). In addition, analysis of Frontier logs has allowed us a deeper understanding of problematic queries and understanding of use cases. Use of the system has grown beyond user analysis and subsystem specific tasks such as calibration and alignment, extending into production processing areas, such as initial reconstruction and trigger reprocessing. With a more robust and tuned system, we are better equipped to satisfy the still growing number of diverse clients and the demands of increasingly sophisticated processing and analysis.
Aging studies for the ATLAS Transition Radiation Tracker (TRT) Akesson, T.; Barberio, E.; Bondarenko, V. ...
International Workshop on Aging Phenomena in Gaseous Detectors,Hamburg, Germany,2001-10-02 - 2001-10-05,
12/2003, Letnik:
515, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
A summary of the aging and material validation studies carried out for the ATLAS Transition Radiation Tracker (TRT) is presented. Particular emphasis is put on the different phenomena observed in ...straw tubes operating with the chosen Xe/CF
4/CO
2 mixture. The most serious effects observed are silicon deposition on the anode wire and damage of the anode wire gold plating. Etching phenomena and active radical effects are also discussed. With a careful choice of all materials and components, and with good control of the water contamination in the active gas, the ATLAS TRT will operate reliably for 10 years at the LHC design luminosity. To demonstrate this fully, more work is still needed on the gas system purification elements, in particular to understand their interplay with the active species containing fluorine created in the avalanche process under irradiation.
We update our CHEP06 2 presentation on the ATLAS experiment software infrastructure used to build, validate, distribute, and document the ATLAS offline software. The ATLAS collaboration's ...computational resources and software developers are distributed around the globe in about 35 counties. The ATLAS offline code base is currently over 7 million source lines of code in 10,000+ C++ classes organized into about 2,000 packages. More than 400 developers contribute code each month. Since our last report, we have developed a powerful, flexible system to request code versions to be included in software builds, made changes to our software building tools, increased the number of daily builds used to validate significant code changes, improved the tools for distributing the code to our computational sites around the world, and made many advancements in the tools to document the code.
The ATLAS Inner Detector consists of three sub-systems, the Pixel Detector at the innermost radius, the Semi-Conductor Tracker at intermediate radii, and the Transition Radiation Tracker (TRT) at the ...outermost radius in front of the electromagnetic calorimeter. The TRT provides a combination of continuous tracking with many projective measurements based on individual drift-tubes (or straws) and of electron identification based on radiator fibres or foils interleaved between the straws themselves. This paper describes the current status of design and construction of the various components of the TRT: the assembly of the barrel modules has recently been completed, that of the end-cap wheels is well underway, and the on-detector front-end electronics is in production. The detector modules and front-end electronics boards will be integrated together over the next year, the barrel and end-cap TRT parts will be assembled and tested with their SCT counterparts during 2005 and installation and commissioning in the ATLAS pit will take place at the end of 2005 and the beginning of 2006.
The basic drift-time measurement properties of the proportional tubes (straws) of the ATLAS TRT detector and the impact of the parameters of the front-end electronics on performance are discussed. ...The performance of two different front-end electronics prototypes has been studied in detail at very high counting rate and is reported here.
Test-beam studies of the ATLAS Transition Radiation Tracker (TRT) straw tube performance in terms of electron–pion separation using a time-over-threshold method are described. The test-beam data are ...compared with Monte Carlo simulations of charged particles passing through the straw tubes of the TRT. For energies below
10
GeV
, the time-over-threshold method combined with the standard transition-radiation cluster-counting technique significantly improves the electron–pion separation in the TRT. The use of the time-over-threshold information also provides some kaon–pion separation, thereby significantly enhancing the B-physics capabilities of the ATLAS detector.
A prototype of the Transition Radiation Tracker (TRT) for the ATLAS experiment at the CERN LHC has been built and tested at the CERN SPS. Detailed studies of the drift-time measurements, alignment ...technique, hit registration efficiency, track and momentum accuracy were performed. A coordinate measurement accuracy of
150
μm
for a single TRT drift tube and momentum resolution of 0.8% for
20
GeV
pions in a
1.56
T
magnetic field were achieved. The results obtained are in agreement with the expected tracking performance of the ATLAS TRT.
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