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Detector Algorithm Quality Assurance Experience with cosmic ray data taking Reconstruction

PMD Software Status. Outline. Detector Algorithm Quality Assurance Experience with cosmic ray data taking Reconstruction Alignment. Ajay Kumar Dash For the PMD. ALICE offline week, CERN. Hardware Mapping information. SDigits. keV-ADC Conversion From Test Beam.

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Detector Algorithm Quality Assurance Experience with cosmic ray data taking Reconstruction

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  1. PMD Software Status • Outline • Detector Algorithm • Quality Assurance • Experience with cosmic ray data taking • Reconstruction • Alignment Ajay Kumar Dash For the PMD ALICE offline week, CERN

  2. Hardware Mapping information SDigits keV-ADC Conversion From Test Beam Digits ESD Flow chart of Simulation & Reconstruction for PMD Simulation 2003 and 2006 Test Beams Hits Raw Data Clustering Gain Pedestal

  3. Detector Algorithm (DA) • Two algorithms for PMD • Pedestal DA: • Calculates Mean, RMS for each channel • No of Events : 1K (to have a better mean and sigma) • Mode of data taking : Standalone, LDC • Gain DA : • Calculates relative gain of each channel • No of events : ~10 Million • Execute on monitoring machine

  4. DA continuing….. pedestal2304.ped pedestal2305.ped pedestal2306.ped pedestal2307.ped pedestal2308.ped pedestal2309.ped ASCII files ===>>Load to MARC for zero- suppression Stores mean and rms for each channel PMD_PED.root ==>> File Exchange Server (FES) ==>> OCDB Copy stored to DAQ DataBase for GAIN DA • Pedestal DA

  5. DA continuing….. Preshower plane Modules installed for pp run Y Pedestal run No : 42155 X One entry corresponds to one channel counts counts rms (adc) mean (adc)

  6. Lessons from Pedestal Analysis • In the beginning, we were unable to read pedestal raw file • Found few bugs in the decoding algorithm • Fixed AliPMDRawStream class • Now successfully read the pedestal data as well as simulated RAW data • RAW data writing class “AliPMDDDLRawData” is modified appropriately Codes are committed to SVN

  7. Both plane adc 0 0 isolated cell 0 0 ADC>0 0 0 DA continuing….. From Simulation PYTHIA Minimum bias 20K events Sqrt(S) = 14 TeV • Cell to cell gain calibration Philosophy Mimics the single particle muon Isolated adc spectra

  8. DA continuing….. • GAIN DA Single particle 1GeV muon • Minimum entries required : ~ 1k per channel • Total # channels : 221184 • Total entries required for stable mean ( or MPV) : ~220 Million • Simulation: • PYTHIA Minimum bias @ Sqrt(S) = 14 TeV • 20K events => ~ 0.5 Million Entries • No of events required : ~10 Million pp events

  9. DAQ Data Base PMD_GAIN_CONFIGFILE (status = 0 Event = 0 MaxEvent ) PMD_PED.root FetchesPMD_GAIN_CONFIGFILE PMD_PED.root Does pedestal sub Change CONFIGFILE (0, 0, MaxEvt) Write PMD_GAIN.root Event processed >= Max Event Isolated cell search FES True False Write a temp file pmd_gain_tempfile.dat Change PMD_GAIN_CONFIGFILE (1, Evt processed, MaxEvt) DA continuing….. • GAIN DA • One RUN may not be enough to give the required statistics • Need to combine few RUNS

  10. Quality Assurance Implemented at various levels • Hits • Sdigits • Digits • Raw data • Reconstruction • ESD

  11. Hits Level QA counts counts energy deposition (eV) total hits in preshower plane

  12. Digits Level QA counts counts total # of cells hit cell adc

  13. Raw Level QA Total # of cells counts Total cell adc Cell adc

  14. Reconstruction Level QA counts counts # of clusters in 6 modules cluster adc • QA histos are also filled for ESD

  15. Status of QA • Some preliminary histos are defined in the codes • and committed to SVN • In some histos, scales are not proper • Also discussing what are the histos to be put • By the end of this week the final code will be committed • as well as the reference histos

  16. Experience with Cosmic data taking • PMD was included in the Cosmic run • Cosmic data are being analysed • For PMD, it was basically random coincidence • But it was a good experience in debugging the reconstruction software as well as to come across • some hardware problem

  17. Experience with cosmic ….. Run no : 42290 Plots are after pedestal subtraction (Only for one event)

  18. Lesson from Cosmic • For corrupted event PMD reconstruction was crashing • Sometime the FEE board address was wrong in cosmic run, but the pedestals are coming alright. No FEE board address found to be wrong • This problem is under investigation • Remedy • Put protection against the corrupt data in • AliPMDRawStream, AliPMDClusterFinder • Modification inside AliPMDClusterFinder to do the • reconstruction for active modules All modified codes are in SVN

  19. Reconstruction • Clustering is the main algorithm for PMD reco • In the old clustering algorithm, there are many • static dimensions • Everything was cleaned up and made dynamic • memory allocation • The code is under the test using the simulated • Pythia events • Will be committed by the end of this week

  20. For Photons inc Eta of incident photon clus Eta of cluster centre

  21. For Photons inc Phi of incident photon clus Phi of cluster

  22. Alignment • Macro to generate the Alignment object and to read the survey data points are in SVN • Once the detector fiducial points are surveyed, • we can immediately generate the misalignment object

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