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Calorimeter Status

Calorimeter Status. Outline : X-mas break activities Preparation for 2012 Ageing & Calibration. 27 March 2012. Pascal Perret LPC Clermont. X-mas break activities. A lot of detector movements. Every thing went well and on schedule!

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Calorimeter Status

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  1. CalorimeterStatus • Outline: • X-mas break activities • Preparation for 2012 • Ageing & Calibration 27 March 2012 Pascal Perret LPC Clermont

  2. X-mas break activities • A lot of detector movements • Every thing went well and on schedule! • But SPD had to be reopened to fix 1 VFE & 1 regulator board problems … Pascal Perret - LPC Clermont

  3. X-mas break activities • Beam pipe protection • Installation of marks on beam pipe protection ECAL • Installation of mechanical end stoppers when beam pipe protection is in place HCAL Pascal Perret - LPC Clermont

  4. X-mas break activities • Dismounting of passive dosimeter detectors for reading • PS: • Mystery of a 2nd VFE reset • Not yet understood … • L0 hadron trigger: cable tests (XCAL platform) • Low rate errors seen in the hadron trigger, from time to time, usually after powering on/off a crate, and solved by re-plugging the cable (in a different connector or even in the same one) • Reason not understood, very small effect on data but … • Several tests done (attenuation of signal, etc.) • No evidence of problem because of weak signal levels in trigger cables • Problem with connectors ? • Additional tests to do … Pascal Perret - LPC Clermont

  5. X-mas break activities • Relative crate phase measurements • FEB modifications to fix the 2 regimes observed (collisions/no collisions) • The reference calibration signal given by the Sequencer of the FEB is affected during collisions by many bit flips • ACTEL flash FPGA known problem • The solution adopted consists in taking the calibration signal before the sequencer • + Fully equip each one of the 2 FEB with 32 channels to reduce X-talks • Cables installation between HCAL and ECAL FEB: • HCAL now connected! • Survey measurements • Measurements of ECAL irradiated modules • collisions (L0) - no collisions (no L0) Pascal Perret - LPC Clermont

  6. X-mas break activities • SPD • Regulator boards • a slight increase in current was observed in some boards (warnings generated during operation!) • Measurements are based on a dedicated fuse • Fuse impedance increase • Exchange the fuse by a higher value  avoid any future problem • 6 boards affected (of a total of 16) in SM 1,2, 7, and 8 top • Boards have been dismounted and the fuses replaced • Tests ok! • 1 VFE showed subtractor problems for 16 channels • Impact only if consecutive events • New VFE board installed (same PMT) Pascal Perret - LPC Clermont

  7. X-mas break activities • SPD • Maraton Backplane problems • Patch-panel measurements: 3.5V instead of 5.5V in 2 channels causing offset problems to all VFEs powered by the same RB. • Problem: loosen nuts at the Maraton backplane providing bad LV cabling contact. • Solution: access from cable platform above the gantry and use an articulated socket wrench and tighten the nuts of the connections. Pascal Perret - LPC Clermont

  8. X-mas break activities • SPD • VFE • A new problem appeared once the detector were closed! • One of the voltages was wrong • Connector problems but … • This connector was stuck with glue as emergency solution (2008) on RB side! • The damaged cable AND the regulator board had to be changed! Pascal Perret - LPC Clermont

  9. X-mas break activities • HCAL • 59 PM replaced:2x more than in 2010/2011! • Dead: 1 • Dark current > 50 nA: 47 • Unstable (rate effect>0.2) • mainly for studies. > 200 nA (13)100-200 nA (14)50-100 nA (20) rate effect > 0.2 (11)dead CW (1) Pascal Perret - LPC Clermont

  10. X-mas break activities • ECAL • 24 PM replaced Green: dismounted for C-W lab. studies (1) Red: the rest of replaced PMs (23) Blue: replaced connectors, PM side (9) Brown: problematic connectors, FEB side (11) Red frame: replaced LEDs (2) Pascal Perret - LPC Clermont

  11. Preparations for the 2012 run • HCAL: HV tuning • Reduction of PMT gain by a factor 2 to reduce radiation damage • ETmax 15 GeV30 GeV, but higher noise • HV recipe produced are based on 137Cs run 26/01/2012 • The ratio is not exactly 0.5: it appears that PMTs’ regulation curves deviate by few % from the exact power law, G=G0∙UB. • The final adjustment of the 30GeV recipe was done using LEDs. Pascal Perret - LPC Clermont

  12. Preparations for the 2012 run • HCAL: HV tuning • Another 137Cs run done 12-Mar-2012for check: • Cs readout system working fine at ETmax=30 GeV • Quite significant gain drift since 26-Jan-2012 observed • The source speed on side C has increased by 12% (34.5 cm/s instead of stable 30.8 in 2009-2012)! • No effect, but to be understood why … Pascal Perret - LPC Clermont

  13. Preparations for the 2012 run • HCAL: Running at ETmax=30 GeV • HCAL PHYSICS HV recipe in use since March 3rd • The LED amplitudes were increased accordingly • Change of trigger calibration constants needed in HCAL Front-End boards: • L0 recipe for ETmax = 30 GeVhave been produced and in used • Problem is that now the transition • 01 L0ADC, is for ADC=3 (it was for ADC=6 before) • For the trigger, we compute 2x2 sums and take the highest: the board electronics noise gives always hadron L0 candidates with non 0 ET. EThadron EThadron BEFORE AFTER Pascal Perret - LPC Clermont

  14. Preparations for the 2012 run • HCAL: Running at ETmax=30 GeV • Input and output L0 hadron candidates are sent from the Selection Boards to the TELL1: 90 candidates. • TELL1 algorithm is to suppress candidates with 0 ET, but now none of the candidates have 0 ET, and the TELL1 must process the 90 candidates, for which it is not designed throttling when running at 1 MHz (these are the worse conditions the system can achieve) • TELL1 firmware was designed to allow suppression of candidates with ET below a given threshold: this feature is back • TELL1 configured with a Zero-Suppression threshold of 160 MeV. • In parallel, add the possibility to do this suppression directly in the Selection Board: the candidates would then be suppressed both in the DAQ and trigger paths. • The energy scale in the reconstruction (Conddb) is going to be recovered Pascal Perret - LPC Clermont

  15. Preparations for the 2012 run • ECAL: HV tuning • LED change during X-mas break: Recovery Ageing Average recovery is on the level of 8÷13%, strongly depends on the detector area (up to 25% in the “horns”) PmPin(12 Mar)/PmPin(30 Oct) PmPin(21 June)/PmPin(21 May) Pascal Perret - LPC Clermont

  16. Preparations for the 2012 run • ECAL: Ageing Pascal Perret - LPC Clermont

  17. Preparations for the 2012 run • ECAL: HV tuning to make uniform the gain after ageing • HV have been changed for ageing over 800pb-1 to take care of refreshing effect : π⁰ calibration used (September 25th) • Required gain change • / Realgain change Required gain change • Change of HV has an impact on timing! • update FEB recipe • LED system time alignment to be tuned • Detector timing to be checked with TAE Pascal Perret - LPC Clermont

  18. ECAL ageing & calibration • An ageing model is being built by Marie-Noelle • 2 components • Neutral (neutral calorimeter clusters) • Distribution of flux weighted by cluster energy • Corrected by cell surface • Fit Aexp(-br) Shape of neutral flux (Tails are not described) • Charged (charged cluster flux) Pascal Perret - LPC Clermont

  19. ECAL ageing & calibration • An ageing model is being built by Marie-Noelle • 2 components • Charged (charged cluster flux) • Take charged cluster weighted by cluster energy • Adjust on the central zone weighted (1/ cell size) • Parametrization A exp(-bx)exp(-cy) • Radiation flux: • 42% Neutral and 58% charged Pascal Perret - LPC Clermont

  20. ECAL ageing & calibration • An ageing model is being built by Marie-Noelle • 2 effects: • Scintillator/fiber ageing proportional to the flux • Decrease of the PMT gain due to current • Depend of the integrated flux / cell • Contribution of the 2 effects adjusted from fine calibration • 52% PMT and 48% radiation • New coefficients are beingproduced for 2011 data Deviation Sept/June Modelisation Pascal Perret - LPC Clermont

  21. Calibration O. Stenyakin, O. Yushchenko • Isolated electrons could also be used • Selection • Only RICH was used to identify electrons; • Track momentum pe > 3. GeV or pe > 10. GeV; • No charged tracks within circle with R = 30 cm at ECAL entrance; • Total Preshower energy deposition associated with track • EPS > 20 MeV; • Total HCAL energy deposition associated with track • EHCAL < 1 GeV. • Sample • It was processed ~3.14x108physical events collected by LHCbin 2011 (MagDown + MagUp BHADRON streams are used), and ~1.15x108e-candidates were selected Pascal Perret - LPC Clermont

  22. Calibration • Isolated electrons could also be used • The methodispromising! • It canbeused to perform ECAL and PS calibration (in progress) • More tests needed Pascal Perret - LPC Clermont

  23. 2012 Running • HCAL • Over a ~200 pb-1period (or at a change of the magnet polarity): • We expect a change of the gain by ~1.5%; corresponding to a ~2.5% hadron loss • Adjustment of the PMT HV according to LED system • During TS • Calibration with Cs source scan • ECAL • With the first collisions give new fine calibration • time estimate ~ 2 weeks • implemented during 1st TS • Update database + ageing • Update calibration monthly Pascal Perret - LPC Clermont

  24. Summary & Conclusion • After TS 100% channels are functional • ECAL & HCAL PMT HV settings have been tuned to make uniform detector and reduce possible radiation damage effects • Time alignment of the detectors have to be adjusted/checked with TAE events an first data • Piquets: • Almost the same team than last year: • -3 + 1 • Funding could become an issue to have persons at CERN … • Calibration and ageing survey to perform all over the year • Production of FmDST is a key tool for ECAL calibration • Not in a routine mode! • Volunteers are welcome! Pascal Perret - LPC Clermont

  25. Pascal Perret - LPC Clermont

  26. Hadron rate understanding Plot from Renaud -30% -25% Muon/Hadron 1.065  1.167 on-line (L0DU) -9% assuming muon rate is stable • Rate not understood ? test to be done when data taking resume Pascal Perret - LPC Clermont

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