Calorimeter Status Pascal Perret LPC Clermont 22 March 2011.
Calorimeter status
description
Transcript of Calorimeter status
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Calorimeter status
•Hardware status •Controls & monitoring•Timing alignment •Calorimeters calibration •Pending issues
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Calorimeter detectors status
Non working channels
Non working LED
Concerns
ECAL 7/6016 10 cells + 11 unstable
Fuse robustness
HCAL 3/1448 2 noisy
PS 0/6016 Mostly Ok LED Not used
SPD 0/6016 10% channelsLED not used
Trigger impact
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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.
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Calorimeters monitoring (1)• Calibration farm monitoring :
LED
Ped
Survey -Pedestal noise & shift-Chi2
Presenter
Expert Expert trend
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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
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Calorimeters Timing
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Xcal Timing status
= 0.75ns
Crate
<>= 0.7ns
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Xcal response stability
K1 =Central/Central+next+2*prev
crate
K1
<> = 0.93= 0.008
8 15 21Crate #
Channel+-1ns+-2ns
Eprs>90MeV
<>= 0.93= 0.012
105
105,5
106
106,5
107
107,5
108
108,5
109
-3 -2 -1 0 1 2 3 4 5
1%
ns
<E-cell>
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PS timing
Spill over correction
Not implemented – in progressAll board < 1ns
On TAE determine the 0 asymetry
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SPD timing
Move by 1ns to be safe
Initial adjustment from occupancy
0.5 ns off
Clock shift
Check with dispaced events
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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 for20% of signal
Exist particles arriving late : estimated spillover4;10-3
Effect low compare to backsplashs …
PS/SPD survey with LED to resume
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Calorimeters calibration
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Hadronic calorimeter calibration • Relative calibration monitored by Cesium source ;Ref 5 Feb
2010 Variation within 3 months
To be compared to LED data
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14Yu. Guz 02/06/2010 14
Response uniform at ~3% RMS for both inner and outer HCAL calibration on data at 4% level in progress.
Hadronic calorimeter calibration
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Electromagnetic calorimeters calibration sequence
Adjusted using 0 mass constraint : - 2 selected Et >205Mev
- SPD to be calibrated
.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)
. Eprs calibration (MIP) (2) . adjustment (3)
EEcal = ciEi
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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 valueNeed 2 more points 1.4 and 1.8
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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
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Estimation of the energy before ECAL ( PS+X)
• Adjusted from the 0 width mass minimization as a function of , for the different calorimeter regions.
varies +-25% for region
Width Mass Chi2
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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 MeVWidth 12.55-> 9.72 MeV
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Method performance & limitations
Adjusted/true : sigma = 2.25%
With tail ~3.5%
Border effect , to be corrected from MC
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Cell calibration on data
Use mass scale and minimize width
Use 80M data ‘ (+70) including Eflow/PRS/calibrations
Iterative procedure /cell
Max(prs1,prs2)<10 MeV -> 7.2 MeVPrs1 > 10 MeV Prs2 < 10 MeV -> 7.54 MeVMin(prs1,prs2)>10 MeV -> 8 MeV
5.78 Mev ( but 2 gaussian)MC width expectation 9MeV
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2 approaches give coherent results
Differences mostly in outer partAnd detector border
These calibrations are available in Reco04
Are they used in the PID for HLT ? Adjustment needed ?
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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
Min
rmsmean
Algorithm to be worked
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On going questions
• Remeasure from data sample corrections issued from MC:– Z shape– S shape – Leakages
• Same cell coefficient for photon & electron : work on (in progress) and others corrections
• New iteration foreseen after work completion
• Calorimeter alignment vs trackers
• Understanding MC behavior ( lateral shower expansion )
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Nice electromagnetic Zoo
Is it going to survive ?
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High pile up events & on line reconstructed 0
0/background decrease by 25-30% , In spite new calibration applied
Study to be done on others caracteristic channels
May data Last week end data
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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 .
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Back up
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High pt 0
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Electron
Electron correction to be tuned for PRS & leakage