TRD Status
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Presentation Transcript
TRD Status Christoph Blume Offline Week, March, 2009
Outline • Raw data • Digitizer and clusterizer • Status calibration • Trigger simulation • Geometry • Project planner • Reconstruction Alexandru (Thu.)
Raw Data • Revision of raw data simulation (W. Park) • Remove split between simulated and real raw data • Bug fixes • Already in 4-16-Release • Raw data decoding • Speed optimization for HLT requirements ongoing (M. Kweon, T. Rascanu) • Reading of online tracklets Before: After:
Digitizer • New data structures for digits (H. Leon Vargas) • Simplified and smaller structures • Faster data access • ZS moved from raw data streamer to digitizer digits consistent with raw data File size: TRD.Digits.root CPU time: Digitization
Clusterizer • Clusterizer has been revised (T. Rascanu) • Original motivation: Speed for HLT • Everything is done inside on loop • Fewer data structures and copying of data involved • Initializations via memset • Streamlining of data reading part • Bug fixes • Same algorithm used in HLT • Can now run at 100Hz • Further improvements in raw data handling
Online Calibration • DAs and preprocessor status • Procedures are ready and operational • DCS datapoints • One has been removed (ADC clock phase) • Calibration object status • Pretrigger and GTU information to be added in TRD/Calib/DCS/AliTRDCalDCS • Will use same infrastructure as implemented to read FEE configuration (fxsproxy, F. Kramer) • Awaiting final definition of contents by experts
Offline Calibration (LHC08d Period) • Gain calibration (offline) • Sum of dE/dx of all clusters attached to a TRD tracklet (no vD calibration yet) • vD and t0 calibration • Offline: vD from amp. peak and t0 from slope at end • Comparison to online results (R. Bailhache)
TRD L1 Trigger Simulation • TRD L1 Trigger consists of two components • Local tracklet finder • Finds short tracklets inside single chamber • Implementes in Tracklet Processor (TRAP) chip • Global Tracking Unit (GTU) • Connects tracklets from several layer to global track • Assigns pt and e-PID • L1 trigger decision (High-pt electrons, , jets)
Tracklet Processor (TRAP) Simulation • AliTRDmcmSim • Simulation of online (hardware) algorithm AliTRDtrapAlu • AliTRDmcmTracklets • Hit detection (3 pads) • Filling fit registers (fit sums) • Calculation of linear fit • Revised version in SVN (J. Klein) • AliTRAPConfig • Other functionalities: • Zero suppression • Digital filters (pedestal, gain, tails)
Global Tracking Unit (GTU) Simulation • Simulation of GTU • Simulates L1 tracking algorithm as done online by FEE • Needed for offline test of trigger algorithms and efficiency evaluation • Input: simulated LTU tracklets • Implementation • AliTRDgtuSim (J. Klein) • Output • AliTRDgtuTracklet • General tracklet base class: AliTRDtracklet
Geometry and Overlaps • Misalignment w/o creating overlaps currently not possible • Position smearing with truncation implemented • Requires quite strong truncations • Some principle problems in current geometry implementation • Envelope volume of single chamber, defining alignable volume • Probably redesign required • Currently being investigated
ESDs • Number of time slices for PID (A. Wilk) • Switch to 8 as default as needed for NN • Tests by Alex: 1060Bytes/ESDtrack on average • Now accepted and implemented
Finished Tasks Since Last Offline Week • Update of raw data simulation (31/10/08) • Decoding trap configuration in readout tree (31/10/08) • Consistent treatment of ZS in digitizer (30/10/08)
Alignment and Geometry • Alignment exercise with cosmics • Uses cosmics data taken in lab (D. Miskowiec talk on offline week last June) • Survey data • Will be analysed to determine alignable objects • However: Not supposed to be used for reconstruction (survey done from A-side only, anyway) • Can be possibly compared to alignment results from cosmics events taken @ P2 (matter of statistics)
