1 / 26

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!

baker-nolan
Download Presentation

Calorimeter Status

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related