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Calorimeter Status

Calorimeter Status. 22 March 2011. Pascal Perret LPC Clermont. Xmas break activities. A lot … SPD Resoldering of a wires on a VFE signal cable connector PS Change of a FEE board ECAL: Change of FEE boards, PMT, integrator boards HCAL Change of FEE boards, PMT TELL1

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Calorimeter Status

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  1. CalorimeterStatus 22 March 2011 Pascal Perret LPC Clermont

  2. Xmas break activities • A lot … • SPD • Resoldering of a wires on a VFE signal cable connector • PS • Change of a FEE board • ECAL: • Change of FEE boards, PMT, integrator boards • HCAL • Change of FEE boards, PMT • TELL1 • Addition of 2 TELL1 for ECAL & PS/SPD • Some unexpected: • HCAL incident …cf TB report on Thursday • Manythanks to the CERN teams: LHCb, Transport, Vacuum, Survey, … Pascal Perret - LPC Clermont

  3. Integratorboards I, nA • New version (install a 100 nF blocking capacitor in the fast signal line): • uses ~90% of the anode current, instead of ~1% • sensitivity ~ 100 DCU counts/μA • DC gain ~2.2 instead of 3000  no stability problems with TL072 (rad hard) NB requires slight modification of CW bases: install 100 nF in series with 25 Ω. This does not affect the signal. Recently, the integrators were upgraded: the 40 mezzanines were replaced with new ones. The work on production and installation of new integrator boards, including modification of host CW bases, was performed in December 2010 – January 2011 (Irina, Pavel, Anatoly Zh.). The nominal sensitivity is 275 mV/μA (110 counts/μA). Measured at the lab before installation in 20 out of 40 boards (Pavel): ±2% deviation. When installed onto CWs, its sensitivity becomes 100 counts/μA because of the 100kΩ “safety” resistor at the CW base. The anode current in ECAL is measured in 40 PMTs out of 6016, through “integrators”, 1-channel mezzanine boards installed at the back of each of these 40 PMT/CWs (original design by Yu. Gilitsky). Each integrator contains an amplifier for measuring current and pass-through for fast signal and LV/MV. The readout is performed via SPECS DCU of regular CALO DAC/HV motherboards. Part of ECAL HV projects. Yu. Guz Pascal Perret - LPC Clermont

  4. Detector status • Good starting point! 7 • SPD: Keep the 0.5 MIP recipe as the default for 2011 • Same threshold conditions as last year for most of the cells, only significant changes in few outliers (0.7 MIPs in 6 cells) • Can easily move to any other value if required by L0 e/ studies. • PS: 1 MIP = 10 ADC count instead of 15 ADC count • Values of HV have been tuned in order to equalize all channels • To be checked with first data Pascal Perret - LPC Clermont

  5. ECAL/HCAL PM darkcurrent 2011-02-06 • All HCAL channels are equipped with « integrator » boards: • Dark current measures can be done for HCAL • To be followed (ok if < 1µA) 06-Feb  12-Mar obviously increasing 2011-03-12 Pascal Perret - LPC Clermont

  6. Online monitoring • Few improvements have been (or are being) implemented: • Automated analyses: • Pedestal following, LED signal & gain monitoring • Reference samples out data are used to tune the thresholds that trigger alarms in the automated analysis. They’re also used to create new alarms based on collision data. S/B=0.19 <M>=139.40.3 =10.40.4 • Monitoring of the 0 mass being also added to the automated analysis: • mass histo available every ten minutes • Fit a gaussian + a polynomial (order 3) • Fill Trending histograms • Only looked at resolved 0 so far. 60min, run 80032 ~1.27, TCK 0x101710 • New plots in the DM page & new alarms on his screen • Occupancy measurements: they can be used to spot dead/hot channels, frozen FEB, etc… • Data will be used to determine the thresholds that will trigger “WARNING/ALARM/FATAL” messages on the shifters screen. Pascal Perret - LPC Clermont

  7. New LED flashing mode • Addition of an extra 11 kHz of periodic triggers for ECAL & HCAL LED flashing • This would reduce appreciably the gain variation of the PMT as function of luminosity • Commissioned thanks to Richard • Data were taken with additional LED flashing of 11, 5.5 and 0 kHz: Rate effect up to +18% occurs. • The rate effect at 5.5 kHz is already close to “saturation”. • No special stability problems found in the 3.5 hour long run with 11 kHz flashing. • New LED reference samples for calibration have been built Rate effect HCAL Pascal Perret - LPC Clermont

  8. Calibration • Different method are used consecutively in order to reach the best performances for ECAL: • Step 1: LED data to have a first calibration and to follow PMT gain changes • Step 2: smoothing of the energy flow: cell inter-calibration • Effect of trigger negligible : < 0.5% absolute effect on inter calibration • Effect of pile-up negligible : < 0.5% absolute effect on inter calibration • Step 3: Fine calibration with 0 • Dead cells and border cells are removed • Large amount of data needed: production of fmDST • To be independent of the Stripping rates and to have an access to all the data collected during 2010: a dedicated production task has to be created. We'reready for production → production team • Step 4: smoothing of the energy flow to allow to recover border cells and surroundings of dead cells • We should reach an ECAL calibration at ~1.5% Pascal Perret - LPC Clermont

  9. Pile-up subtraction • Observation on 2010 data : e/p and m(0) significantly increases with nPV • pile-up effect measured as +(0.68±0.07) MeV/c2 per PV above 1 on m(0) • was decided to subtract <EPU> per bin on SpdMult (to be independent of trigger GEC) • not trivial to define the pile-up energy <EPU> : several unsuccessful attempts … • Olivier found a working method: • for cluster at (x,y) look at 3x3 energy at the mirror position (-x,-y) • if Emirror < Ecluster /2 it is a valid ‘pile-up’ energy for that cluster • AverageEmirror per bin of SpdMult→ <EPU>/bin =<Emirror>(bin i+1) - <Emirror>(bin i) • More at: http://indico.cern.ch/getFile.py/access?contribId=27&sessionId=3&resId=0&materialId=slides&confId=130600 converted to (floating ADC) up to ~4-5 ADC per 50 Spd in the inner-bending plane Pascal Perret - LPC Clermont

  10. Pile-up subtraction • Performance on reconstructed 0mass • check on fill 1427 & 1375 (October 2010 – nu > 2) (0→ unconverted only) • Pile-up correction implemented in software • <EPU>=0.88 ADC per bin of 50 SpdMult above 200 for 3x3 area • No longer dependency with nPV • Maybeslightnegative gradient on mass after correction (-0.08±0.04)MeV/c2 • Note: the resolutionisσ = 7.1 MeV/c2 for early data (nu << 1 , april-june) • Note : before/after correction does not correspond to samecondDB (Ecorrection/Calibration) • So absolute mass and sigma is not directly comparable (‘after correction’isbettertuned) Pascal Perret - LPC Clermont

  11. Reconstruction tuning for MC10 • Purpose : extract reconstruction parameters from MC10 data in the same way it has been done for data : • few months needed for data, hopefully a couple of weeks for MC • Tuning not yet completed • just preliminary/intermediate results shown today • S-corrections and alignment : • initial MC parameters obtained from DC04/DC06 sample using MC-truth info • Fit : yc = b asinh[yb/0.5 cosh(0.5/b)]+Δy S-shape main parameter : Track Y MC10 Inner Ecal • Data parameters was 20-30% higher than (old) MC • now: 5-7% larger than MC10 Cluster Y Pascal Perret - LPC Clermont

  12. SPD Alignment • The SPD alignment wrt trackers has been measured for 2010 data • X coordinate: seem to be rotated around Z-axis ( / \ shape ) • Rotation C-side: (0,0,-0.028º) • Rotation A-side: (0,0,0.041º) • Global vertical displacement equivalent for all SM (~-7mm) • To be checked X coordinate • Try to implement corrections in the condDB • Rotation not foreseen … • And to re-align detectors during a long shut-down … Pascal Perret - LPC Clermont

  13. SPD vs M1 multiplicity • From Giovanni Passaleva, 17 January 2011: • M1 hits ~ 1/2 SPD hits • Miriam had a look: • M1 hits ~ 1.1 SPD hits (October 2010 data (BHadron stream)) • Same relation in MC than in data: MC10 (bb-bar evts) To bechecked! Pascal Perret - LPC Clermont

  14. First look at 2011 data • SPD: • Occupancy with first 2011 data • looks more homogeneous • PS: • The MIP is consistently around 11-12 ADC counts for all boards. • Reminder: 10 ADC counts is the value of the most probable value of the Landau function. • The new calibration set in the electronics seems basically correct at that stage. • Fine analysis with tracks is required for a more detailed analysis / per channel. • Timing: • Relative alignment of VFE within σ=0.5 ns ! • alignment better than ±2 ns. Some ~ 1 ns crate effects? Pascal Perret - LPC Clermont

  15. First look at 2011 data • ECAL Pascal Perret - LPC Clermont

  16. Summary • Calorimeter detectors are in a good shape • Few access needed during the next technical stop: • Annual control of the HCAL Cs source • Repair of HCAL turbine C-side (control board) • Fix minor problems, … • First look at 2011 data encouraging: • Time alignment ok, … • Priority with first 2011 data • Check gains • Check spill over corrections for PS (needed with 75ns BC) • Calibration • Re-measure ECAL and PS, SPD (mis)alignment Pascal Perret - LPC Clermont

  17. Summary • Software: • A lot of new corrections have been computed and implemented: • Energy correction, S-correction, L-correction, Alignment, … • Pile-up correction implemented in software • No longer dependency with nPV • Energy double counting in pi0 reconstruction understood • Reconstruction tuning for MC10 well advanced • good agreement with 2010 data • New online monitoring version (to be active at pit soon) • Fine and detailed corrections took long time (and manpower) and are still not fully completed • Should be much faster with 2011 data • Hopefully we’ll just need to check the 2010 parameters are still OK for 2011 • The tools to extract parameters are mostly in place Pascal Perret - LPC Clermont

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