ID Alignment: CSC

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ID Alignment: CSC. The ATLAS CSC (Computing System Commissioning) served to validate the ATLAS ID Alignment algorithms with large MC samples Our group participates in the Global 2 silicon alignment based on the tracks 2 minimization - PowerPoint PPT Presentation

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Diapositiva 1

ID Alignment: CSCThe ATLAS CSC (Computing System Commissioning) served to validate the ATLAS ID Alignment algorithms with large MC samplesOur group participates in the Global2 silicon alignment based on the tracks 2 minimization

Needs to invert (diagonalize) a NAlixNAli matrix (up to 35k x 35k)

ID Alignment: CSCDuring the CSC the ID alignment strategy was settle level by levelFrom big structures (few DoFs)Barrel layers and end caps disks (hundreds of DoFs)To modules (35K DoFs)

ID Alignment: CSCResults of the Global2 method during the CSC were used in the ATLAS detector paper The ATLAS Collaboration, G. Aad et al., The ATLAS Experiment at the CERN Large Hadron Collider, JINST 3 (2008) S08003

ID Alignment operation scheme

ID Alignment FDRThe 2008 ATLAS Full Dress Rehearsals main purpose was an evaluation of different data streaming techniques for physics analysis and calibrationThe calibration and alignment was run like in real data taking with a 24 hours loopWe participated actively in all FDR exercisesRunning the alignment jobsProducing alignment constantsReporting at the daily operations meetingsValidating the alignment constantsOur alignment constants were used for the official production

ID Alignment FDRDuring the 2008 ATLAS FDRs the alignment scheme was implemented, tested and validated.

The Ringberg ID alignment schemeID Alignment with real cosmic data 2008During the fall of 2008, ATLAS collected several millions of real cosmic ray tracks.They served to commission the real detectorAlign the real Inner Detector with real dataB field ONB field OffTotalAll tracks4.940.0002.670.0007.610.000SCT hits1.150.000880.0002.030.000Pixel Hits230.000190.000420.000

ID Alignment with real cosmic data 2008Our first set of alignment constants with the Global2 was validated 18th /September/2008 and it was ready to reconstruct the first LHC collisions expected the following dayThe experience with the real data helped to identify new alignment levels (not anticipated in the simulation) to account for collective movements of modules during the assemblyPixel half shellsPixel and SCT ladders

ID Alignment with real cosmic data 2008Our Global2 set of constants are used for theOfficial ATLAS cosmic data reprocessingBy the Cosmic analysis groupValidation performed with track splitting in upper and lower segment and check the matching

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