calorimeter status

28 June 2010 LHCb week St PetersburgM.N Minard

1

Calorimeter status

•Hardware status •Controls & monitoring•Timing alignment •Calorimeters calibration •Pending issues


2

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


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.


4

Calorimeters monitoring (1)• Calibration farm monitoring :

LED

Ped

Survey -Pedestal noise & shift-Chi2

Presenter

Expert Expert trend


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


6

Calorimeters Timing


7

Xcal Timing status

= 0.75ns

Crate

<>= 0.7ns


8

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>


9

PS timing

Spill over correction

Not implemented – in progressAll board < 1ns

On TAE determine the 0 asymetry


10

SPD timing

Move by 1ns to be safe

Initial adjustment from occupancy

0.5 ns off

Clock shift

Check with dispaced events


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 for20% of signal

Exist particles arriving late : estimated spillover4;10-3

Effect low compare to backsplashs …

PS/SPD survey with LED to resume


12

Calorimeters calibration


13

Hadronic calorimeter calibration • Relative calibration monitored by Cesium source ;Ref 5 Feb

2010 Variation within 3 months

To be compared to LED data


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


15

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


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 valueNeed 2 more points 1.4 and 1.8


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


18

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


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 MeVWidth 12.55-> 9.72 MeV


20

Method performance & limitations

Adjusted/true : sigma = 2.25%

With tail ~3.5%

Border effect , to be corrected from MC


21

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


22

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 ?


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

Min

rmsmean

Algorithm to be worked


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 (in progress) and others corrections

• New iteration foreseen after work completion

• Calorimeter alignment vs trackers

• Understanding MC behavior ( lateral shower expansion )


25

Nice electromagnetic Zoo

Is it going to survive ?


26

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


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 .


28

Back up


29

High pt 0


30

Electron

Electron correction to be tuned for PRS & leakage

calorimeter status

Documents

calibration farm monitoring

outer hcal calibration

led data flashing

calibration farm summaries

led datayu

response uniform

nsxcal response stability

daily control