status/plans for em calibration s. rajagopalan july 13, 2006 atlas week, stockholm

Status/Plans for EM Calibration

S. RajagopalanS. Rajagopalan

July 13, 2006July 13, 2006

ATLAS Week, StockholmATLAS Week, Stockholm

ATLAS Week, Stockholm, July 2006ATLAS Week, Stockholm, July 2006S. RajagopalanS. Rajagopalan 2

Outline

Summarize the present calibration in AthenaSummarize the present calibration in Athena Cell and Cluster level corrections

Short term updates (plan for 12.0.2)Short term updates (plan for 12.0.2)

As-built detector simulationAs-built detector simulation

Plans for calibration data challenge.Plans for calibration data challenge.


Cell level calibration

E = (ADC A) * (A GeV) * ∑ ai (ADCi – ped)

ai = Optimal filter coefficients

ADC A ADCADCDACDAC from electronic calibration (“Ramp”) from electronic calibration (“Ramp”) Mphys/Mcal correction of amplitude bias calibration-physics pulseMphys/Mcal correction of amplitude bias calibration-physics pulse DACDACAA injected current from calibration ( injected current from calibration (~1/Rinj)~1/Rinj)

A GeV derived from Test-Beam data Includes the sampling fractionIncludes the sampling fraction Can also be decomposed from fSampl*(MeV/Can also be decomposed from fSampl*(MeV/A)_LarA)_Lar

This decomposition relies on fSampl from Geant4This decomposition relies on fSampl from Geant4 For EMEC: MeV/For EMEC: MeV/A A = = MeV/MeV/A_0A_0 * * bb /(1+ /(1+aa((--0) )0) )

a, b derived from TB data a, b derived from TB data

Current digitization/reconstruction uses sampling fraction derived from Current digitization/reconstruction uses sampling fraction derived from

simulation, the rest from TB02 measurementssimulation, the rest from TB02 measurements


Cell Level Calibration (2)

Calibration applied at ROD and HLT would probably be simpler.Calibration applied at ROD and HLT would probably be simpler. Studying the possibility to apply “linear calibration” at the RODs and Studying the possibility to apply “linear calibration” at the RODs and

applying a refined higher order electronics calibration and correcting for applying a refined higher order electronics calibration and correcting for pedestal shifts during offline reconstruction.pedestal shifts during offline reconstruction.

HV corrections (dead on one side or non-nominal)HV corrections (dead on one side or non-nominal)

Corrections for pathological cells (noisy, dead)Corrections for pathological cells (noisy, dead)

Correction for temperature variation Correction for temperature variation

Correction for argon purityCorrection for argon purity

Inter-calibration between calorimeter regions obtained from Z analysis.Inter-calibration between calorimeter regions obtained from Z analysis.

Most of these have yet to be implemented in the current reconstruction.Most of these have yet to be implemented in the current reconstruction. But the software structure allows for easy plugi-in’s of correction toolsBut the software structure allows for easy plugi-in’s of correction tools


Cluster Level Corrections

Two clustering algorithms are used:Two clustering algorithms are used: Sliding Window algorithm producing EM clusters in 5x5, 3x5, 3x7Sliding Window algorithm producing EM clusters in 5x5, 3x5, 3x7

Topological clustering with seed 6,3,0Topological clustering with seed 6,3,0 Being studied for e-gamma reconstruction..Being studied for e-gamma reconstruction..

Sliding Window clusters are corrected for:Sliding Window clusters are corrected for: Eta and phi position correctionsEta and phi position corrections

Energy modulations vs eta, phiEnergy modulations vs eta, phi

Lateral out of cone energy correctionsLateral out of cone energy corrections

Longitudinal corrections including upstream matter & leakageLongitudinal corrections including upstream matter & leakage

Gap corrections, if relevantGap corrections, if relevant

Correct for residual HV effects and pathological cells.Correct for residual HV effects and pathological cells.

Overall energy scaleOverall energy scale

Corrections in 12.0.1 all derived from DC2 single electronsCorrections in 12.0.1 all derived from DC2 single electrons


S-shape corrections

Finite granularity of middle sampling Finite granularity of middle sampling (0.025x0.025)(0.025x0.025) not small compared to shower width not small compared to shower width

Simple energy weighted position (Simple energy weighted position () measurement pulled toward middle of cell) measurement pulled toward middle of cell

Corrections derived from single electrons (Snyder)Corrections derived from single electrons (Snyder)

SnyderSnyder


Energy modulation

Energy modulations as a function of phiEnergy modulations as a function of phi

Derived for different eta positionsDerived for different eta positionsEnergy modulations as a function of etaEnergy modulations as a function of eta

Derived for different cone sizes and eta binsDerived for different cone sizes and eta bins0.1 to 0.2% effect0.1 to 0.2% effect

S. SnyderS. Snyder


Longitudinal weights

of functionsonly ,,, 30

332100

2

2

2

wwoff

EwEEEwoffE

EE

rec

N

i E

itrue

irec

itrue

]2[]1[]0[ _ parEparEEparE scigapEMECEMBrec

5.2

6.13.1 Different parametrization in gap region (gap scintillator energy is used):Different parametrization in gap region (gap scintillator energy is used):

Weights extracted via a chiWeights extracted via a chi22 fit on single electrons (S. Paganis) fit on single electrons (S. Paganis)

Will be updated for 12.0.2 with latest geometry tag: DC3-05Will be updated for 12.0.2 with latest geometry tag: DC3-05


Longitudinal weights

A more sophisticated expression has been demonstrated to improve A more sophisticated expression has been demonstrated to improve linearity and good resolution at TB02 (T. Carli)linearity and good resolution at TB02 (T. Carli)

impact cellbremleak3,1

calo5.01 ).E()).depth(1).().().)(().()(( fffEEdEEEcEEbEaE

i ivisVis

PSVisPS

rec

E loss upstream of PS E loss between PS and calo

calo sampling fraction+ lateral leakage E dependent

Longitudinalleakage 1.5 X0, 3.6 %@10 GeV

0.9 X0, 4.1 %@10 GeV > 30 X0, 0.3 %@10 GeV

Better than 0.1 % over 20-180 GeV:Better than 0.1 % over 20-180 GeV: Done only at one Done only at one position in a position in a setup with less material than in setup with less material than in ATLAS and no B fieldATLAS and no B field Implementation of this method in Implementation of this method in Athena is being explored by Athena is being explored by L.Carminati, L. Mandelli, et. al.L.Carminati, L. Mandelli, et. al. using “calibration hits”using “calibration hits”

T. CarliT. Carli


Gap corrections

Gap corrections re-derived for 12.0.0 using gap scinitillators (S. Gap corrections re-derived for 12.0.0 using gap scinitillators (S.

Paganis, J. Hoffman)Paganis, J. Hoffman) No gap scintillators in early Rome reconstructionNo gap scintillators in early Rome reconstruction

Comparison of Comparison of E/EE/Etrue true in Release 11.5.0 and 12.0.0:in Release 11.5.0 and 12.0.0:

11.5.011.5.0

Mean = -0.107Mean = -0.107±±0.0150.015

σσ = 0.123 = 0.123±±0.0230.023

12.0.112.0.1

Mean = -0.015Mean = -0.015±±0.0070.007

σσ = 0.066 = 0.066±±0.0090.009

HoffmanHoffman


Performance(using simulation from 11.0.4x)

Slightly worse than TDR because of increased materialSlightly worse than TDR because of increased material

All corrections need to be re-derived and optimized as well.All corrections need to be re-derived and optimized as well.

Need to use Zee for intercalibration of regions

448 regions in ATLAS (denoted by i)

Eireco = Eitrue(1+αi) Mijreco =MZ(1+(αi+αj)/2)

fit to reference distribution abd propagate αi

S. PaganisS. PaganisS. PaganisS. Paganis


Short term plan

The present 12.0.1 release have corrections that were derived The present 12.0.1 release have corrections that were derived

using DC2 simulation, single electrons.using DC2 simulation, single electrons.

These need to be re-derived as the simulation has acquired several These need to be re-derived as the simulation has acquired several

“as-built” realistic features.“as-built” realistic features. Being re-done with 11.0.x simulation, Will be available for 12.0.xBeing re-done with 11.0.x simulation, Will be available for 12.0.x Will also need to be re-derived with 12.0.x (as-built simulation).Will also need to be re-derived with 12.0.x (as-built simulation).

Corrections are also different for electrons & photonsCorrections are also different for electrons & photons Software infrastructure in place to implement different e-Software infrastructure in place to implement different e-

corrections, Will try to get it in 12.0.2corrections, Will try to get it in 12.0.2


As-built geometry in simulation

Extensive work has gone into updating the simulation with:Extensive work has gone into updating the simulation with:

Material (M. Thoiye, V. Tsulai): Material (M. Thoiye, V. Tsulai): Solenoid supports like rails and titanium blocks. Solenoid supports like rails and titanium blocks. Electronic crates mounted on barrel endcaps. Electronic crates mounted on barrel endcaps. cables from the inner detector in the crack region. cables from the inner detector in the crack region. radiation shielding in the FCAL region. radiation shielding in the FCAL region. moderator and MBTS on the endcap. moderator and MBTS on the endcap.

Geometries have been thoroughly reviewed by sub-system expertsGeometries have been thoroughly reviewed by sub-system experts Some material on the endcap itself is not sufficiently declashed Some material on the endcap itself is not sufficiently declashed

(overlapping volumes in heaters, cables, crates) (overlapping volumes in heaters, cables, crates) in progress for 12.0.2in progress for 12.0.2


As-built simulation(mis-alignments)

Misalignments for the barrel are in database (V. Tsulai, G. Unal). Misalignments for the barrel are in database (V. Tsulai, G. Unal). Misalignments of large pieces: Misalignments of large pieces:

Cryostats, EMBarrel (pos$neg), SolenoidCryostats, EMBarrel (pos$neg), Solenoid Translation and rotationTranslation and rotation

Typical misalignments introduced and tested.Typical misalignments introduced and tested. Simulation samples generated, reconstructed – being studied (S.Laplace, R. Zitoun)Simulation samples generated, reconstructed – being studied (S.Laplace, R. Zitoun)

preliminary: z deplacement of cryostat 4cm reconstructedpreliminary: z deplacement of cryostat 4cm reconstructed senstivity to translation/tilt 1mm/mrad with 10k Zsenstivity to translation/tilt 1mm/mrad with 10k Z

Endcap misalignments pending a resolution of the cryostat issueEndcap misalignments pending a resolution of the cryostat issue Sagging of electrodes and absorbers introduced (Parrour, Unal)Sagging of electrodes and absorbers introduced (Parrour, Unal) Establish a standard way to specify mis-alignments in DBEstablish a standard way to specify mis-alignments in DB

Will be done for 12.0.2 (Boudreau)Will be done for 12.0.2 (Boudreau) Deformation (pear shape) of calorimeter NOT planned until Rel. 13Deformation (pear shape) of calorimeter NOT planned until Rel. 13


As-built simulation

ResponseResponse Decrease of the response for charge deposited close to EMEC Decrease of the response for charge deposited close to EMEC

electrode (V. Niess, G. Unal). electrode (V. Niess, G. Unal). HV imperfections introduced; our first use of Conditions DB in HV imperfections introduced; our first use of Conditions DB in

simulation (V. Tsulai, G. Unal) simulation (V. Tsulai, G. Unal)

Calibration Hits Calibration Hits (M. Leltchouk, G. Pospelov et. al.)(M. Leltchouk, G. Pospelov et. al.) Allows saving of energy deposited in active (LAr) and inactive Allows saving of energy deposited in active (LAr) and inactive

(absorbers) and dead material (such as upstream material) in fine (absorbers) and dead material (such as upstream material) in fine granularity.granularity.

Dead material hits produced by default in Release 12.Dead material hits produced by default in Release 12.

Broken into EM, Hadronic, invisible or escaped energy deposits.Broken into EM, Hadronic, invisible or escaped energy deposits. Extensively used for EM and hadronic calibration.Extensively used for EM and hadronic calibration.

EM sampling fraction & longitudinal weights being studied in detail by EM sampling fraction & longitudinal weights being studied in detail by using calibration hits (L. Carminati et.al.)using calibration hits (L. Carminati et.al.)

Local hadron calibration weights using calibration hits (S. Menke et. al.)Local hadron calibration weights using calibration hits (S. Menke et. al.)


Plans for CDC

Re-derive the cluster corrections from as-built geometry in 12.0.xRe-derive the cluster corrections from as-built geometry in 12.0.x Present correction are DC2 based and being re-derived with Present correction are DC2 based and being re-derived with

11.0.4211.0.42 Likely to lead to deterioration of resolution in end-cap due to Likely to lead to deterioration of resolution in end-cap due to

increased material. Need to handle this better in reconstruction.increased material. Need to handle this better in reconstruction.

Simulate events with following conditions and develop Simulate events with following conditions and develop

procedures on how to correct for them in reconstructionprocedures on how to correct for them in reconstruction Introduce realistic misalignments between large pieces.Introduce realistic misalignments between large pieces. Electrode/Absorber saggingElectrode/Absorber sagging Introduce mis-calibration (but perhaps can be done post-digitization)Introduce mis-calibration (but perhaps can be done post-digitization) HV pathologiesHV pathologies Increased up-stream matterIncreased up-stream matter

Effects would be studied on samples of single e, Effects would be studied on samples of single e, , Z, Zeeee


Concluding Remark

Calorimeter Calibration Workshop, Sant Feliu, Sept. 5-8, 2006Calorimeter Calibration Workshop, Sant Feliu, Sept. 5-8, 2006

Organized by Martine Bosman, Ilya KorolkovOrganized by Martine Bosman, Ilya Korolkov

Complete review of the present calibration.Complete review of the present calibration.

Electronics, EM, Hadronic, in-situ, TriggerElectronics, EM, Hadronic, in-situ, Trigger Simulation, Testbeam, commissioningSimulation, Testbeam, commissioning

Discussion on calibration strategies during early runningDiscussion on calibration strategies during early running

An “oversight panel” has been formed to closely look at our present An “oversight panel” has been formed to closely look at our present

work, help promote discussions and help us plan the road ahead:work, help promote discussions and help us plan the road ahead: M. Cavalli-Sforza, T. Davidek, N. Ellis, D. Froidevaux, D. Lissauer, J. StarkM. Cavalli-Sforza, T. Davidek, N. Ellis, D. Froidevaux, D. Lissauer, J. Stark

status/plans for em calibration s. rajagopalan july 13, 2006 atlas week, stockholm

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