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Calorimeter status

Calorimeter status. Hardware status Controls & monitoring Timing alignment Calorimeters calibration Pending issues. Calorimeter detectors status. Calorimeters controls. Daily control followed by piquet (12 ) : 9 days with 2 days overlap HV errors (April)

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Calorimeter status

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  1. Calorimeter status Hardware status Controls & monitoring Timing alignment Calorimeters calibration Pending issues LHCb week St Petersburg M.N Minard

  2. Calorimeter detectors status LHCb week St Petersburg M.N Minard

  3. Calorimeters controls • Daily control followed by piquet (12 ) : • 9 days with 2 days overlap • HV errors (April) • DAQ errors or configuration errors • OPC server • Daily checks of currents and power supllies • Analyse calibration farm summaries ECS • Updated for Temperature controls of VFE • System very stable. LHCb week St Petersburg M.N Minard

  4. Calorimeters monitoring (1) • Calibration farm monitoring : • Survey • Pedestal noise & shift • Chi2 LED Ped Presenter Expert Expert trend LHCb week St Petersburg M.N Minard

  5. Calorimeters monitoring (2) • LED data flashing at 10Hz are used to monitor the ECAL & HCAL calorimeters • Survey • LED response • Stability • PMT/pin ratio • Give • Trend • Problem rate • Algorithm in progress • Should provide: • Dead channels • Gain change • Still a lot of improvements foreseen : • Data manager & data quality • DB handling LHCb week St Petersburg M.N Minard

  6. Calorimeters Timing LHCb week St Petersburg M.N Minard

  7. Xcal Timing status Crate <>= 0.7ns s= 0.75ns LHCb week St Petersburg M.N Minard

  8. Xcal response stability +-1ns +-2ns Channel <>= 0.93 s= 0.012 Eprs>90MeV K1 =Central/ Central+next+2*prev crate <E-cell> <> = 0.93 s= 0.008 1% 8 15 21 Crate # ns K1 LHCb week St Petersburg M.N Minard

  9. PS timing Spill over correction On TAE determine the 0 asymetry All board < 1ns Not implemented – in progress LHCb week St Petersburg M.N Minard

  10. 0.5 ns off Clock shift SPD timing Initial adjustment from occupancy Check with dispaced events Move by 1ns to be safe LHCb week St Petersburg M.N Minard

  11. SPD spill over • At data taking start spill over has consequence on trigger • Work conducted to estimate the effect importance • lab tests & 2010 data used Substrator work as expected compensated for 20% of signal Exist particles arriving late : estimated spillover 4;10-3 Effect low compare to backsplashs … PS/SPD survey with LED to resume LHCb week St Petersburg M.N Minard

  12. Calorimeters calibration LHCb week St Petersburg M.N Minard

  13. Hadronic calorimeter calibration • Relative calibration monitored by Cesium source ;Ref 5 Feb 2010 Variation within 3 months To be compared to LED data LHCb week St Petersburg M.N Minard

  14. Hadronic calorimeter calibration Response uniform at ~3% RMS for both inner and outer HCAL calibration on data at 4% level in progress. Yu. Guz 02/06/2010 14 LHCb week St Petersburg M.N Minard

  15. Electromagnetic calorimeters calibration sequence Adjusted using p0 mass constraint : - 2 g selected Et >205Mev - SPD to be calibrated EEcal = S ciEi . Eprs calibration (MIP) (2) . b adjustment (3) .Account for # leakages default values from MC . Cell calibration ci - initial gain adjustment from PE (8%) - Eflow calibration (4%) -> early April (1) - Fine calibration (4) LHCb week St Petersburg M.N Minard

  16. SPD calibration • Threshold adjustment of SPD • Run taken for theoritical 0.3 , 0;5, 0;8, 1. MIP Numerical description Analytical description Correction to the current settings (active) 3% channels no setting value Need 2 more points 1.4 and 1.8 LHCb week St Petersburg M.N Minard

  17. E-flow PS & ECAL • First relative inter-calibration on collision data using an ‘energy flow’ method • smoothing the transverse energy deposit on the basis of the average deposit of neighbour channels • Calorimeter standalone method • requiring a relatively small statistics (~ 1M events) Method can be applied to PRS & HCAL Eflow-> 4-5% PS calibration • Uses MIP response in PRS individual cells • Intercalibration at 5% level Typical cell LHCb week St Petersburg M.N Minard

  18. Estimation of the energy before ECAL ( PS+X) • Adjusted from the p0 width mass minimization as a function of b , for the different calorimeter regions. b varies +-25% for region Chi2 Width Mass LHCb week St Petersburg M.N Minard

  19. Fine cell calibration • Iterative method developed for fine cell calibration : • Take converter or non converted photon • A tool building and iteratively using FMDst has been built (Kali) • Exercised on 100M decalibrated data Mass vs iteration After Mass 138.8 -> 135 MeV Width 12.55-> 9.72 MeV LHCb week St Petersburg M.N Minard

  20. Method performance & limitations Adjusted/true : sigma = 2.25% With tail ~3.5% Border effect , to be corrected from MC LHCb week St Petersburg M.N Minard

  21. Cell calibration on data Use 80M data ‘ (+70) including Eflow/PRS/b calibrations Use mass scale and minimize width Iterative procedure /cell Max(prs1,prs2)<10 MeV -> 7.2 MeV Prs1 > 10 MeV Prs2 < 10 MeV -> 7.54 MeV Min(prs1,prs2)>10 MeV -> 8 MeV MC width expectation 9MeV 5.78 Mev ( but 2 gaussian) LHCb week St Petersburg M.N Minard

  22. 2 approaches give coherent results Differences mostly in outer part And detector border These calibrations are available in Reco04 Are they used in the PID for HLT ? Adjustment needed ? LHCb week St Petersburg M.N Minard

  23. PMT stability over 2 months • Estimate of stability for cell i: • “Pessimistic”: •  S1(i) = (Max(i) – Min(i)) / Mean(i) • 3.4% • “Optimistic”: •  S2(i) = rms(i) / Mean(i) (0.7%) Max mean rms Min Algorithm to be worked LHCb week St Petersburg M.N Minard

  24. On going questions • Remeasure from data sample corrections issued from MC: • Z shape • S shape • Leakages • Same cell coefficient for photon & electron : work on b (in progress) and others corrections • New iteration foreseen after work completion • Calorimeter alignment vs trackers • Understanding MC behavior ( lateral shower expansion ) LHCb week St Petersburg M.N Minard

  25. Nice electromagnetic Zoo Is it going to survive ? LHCb week St Petersburg M.N Minard

  26. High pile up events & on line reconstructed p0 p0/background decrease by 25-30% , In spite new calibration applied Last week end data May data Study to be done on others caracteristic channels LHCb week St Petersburg M.N Minard

  27. Status & plans • Calorimeter hardware and controls performs well . • Large progress have been made in detector understanding • 1st fine calibration is released since end of May and Repro04 uses it … • Still a lot to do for the 1% calibration goal at high energy …will need high energy sample . LHCb week St Petersburg M.N Minard

  28. Back up LHCb week St Petersburg M.N Minard

  29. High pt p0 LHCb week St Petersburg M.N Minard

  30. Electron Electron correction to be tuned for PRS & leakage LHCb week St Petersburg M.N Minard

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