Test TPC Off-line Test TPC Off-line analysisanalysis

Marian IvanovMarian Ivanov

TPC commissioningTPC commissioning

• Test of TPC Test of TPC o 2 TPC sectors 2 TPC sectors

• not full TPC operational, no magnetic field not full TPC operational, no magnetic field

o Cosmic test Cosmic test • 3 voltages settings3 voltages settings

1 nominal voltage (statistic ~ 2000 triggered events 1 nominal voltage (statistic ~ 2000 triggered events (~10000 tracks))(~10000 tracks))

+- 50 volts (statistic ~ 300 events) +- 50 volts (statistic ~ 300 events)

o Laser testLaser test• Drift velocity determination, monitoringDrift velocity determination, monitoring• AlignmentAlignment

Stability test – important for ExB correctionStability test – important for ExB correction

Data flowData flowRaw data – Date format format

Raw data – Root format forma

Rootification

ESD – Tracks – default modeClusters and Signals (calibration mode)

Reconstruction (Clusterization, tracking)

OfflinePost processing Calibration

Data volumeData volume• Raw data – One run (given sector ,voltage Raw data – One run (given sector ,voltage

setting)setting)o 60 files x 1.5 GBy ~ 90 GBy60 files x 1.5 GBy ~ 90 GByo Public access - Castor path Public access - Castor path

/castor/cern.ch/user/m/miranov/testtpc2006/rawdata/castor/cern.ch/user/m/miranov/testtpc2006/rawdata• Rootified dataRootified data

o 60 files x 0.65 GBy ~ 40 GBy60 files x 0.65 GBy ~ 40 GByo Public access - Castor path Public access - Castor path

/castor/cern.ch/user/m/miranov/testtpc2006/rootdata/castor/cern.ch/user/m/miranov/testtpc2006/rootdata• Reconstructed dataReconstructed data

o 60 files x (AliESDs.root ~ 0.4 MBy + TPCtracks.root ~ 60 files x (AliESDs.root ~ 0.4 MBy + TPCtracks.root ~ 0.8 MBy + FitSignal.root ~ 100 MBy) ~ 6 GBy0.8 MBy + FitSignal.root ~ 100 MBy) ~ 6 GBy

o Public access - Castor path Public access - Castor path /castor/cern.ch/user/m/miranov/testtpc2006/rec0606/castor/cern.ch/user/m/miranov/testtpc2006/rec0606

• Further reconstruction pass with new directory createdFurther reconstruction pass with new directory created

CPU requirementsCPU requirements• Raw data to Rootified dataRaw data to Rootified data

o Downloading of the data to local storage Downloading of the data to local storage • 60 x 3 min ~ 3 hours60 x 3 min ~ 3 hours

o Rootification Rootification • 60 x 3 min ~ 3 hours60 x 3 min ~ 3 hours

o Downloading and rootification done in bunches of files Downloading and rootification done in bunches of files (Done in parallel)–Response time ~ 3 hours(Done in parallel)–Response time ~ 3 hours

• ReconstructionReconstructiono 60 x 40 min60 x 40 mino Done in parallel on LSF batch systemDone in parallel on LSF batch systemo Response time ~ 1-2 hour (waiting time in batch queue)Response time ~ 1-2 hour (waiting time in batch queue)

• Total response time given mainly by data Total response time given mainly by data transfertransfero In optimal condition – Direct storage of rootified data In optimal condition – Direct storage of rootified data

on CASTOR + High priority in the batch queue ~ 1 houron CASTOR + High priority in the batch queue ~ 1 hour

Offline Reconstruction Offline Reconstruction (Cluster finder)(Cluster finder)

• Find clustersFind clusterso TPCRecPoints.root (Default mode)TPCRecPoints.root (Default mode)

• + In Mode without pedestal subtraction+ In Mode without pedestal subtractiono Estimation of pedestal event by eventEstimation of pedestal event by evento Pedestal and noise calibration Pedestal and noise calibration

(histograming and fitting of amplitude (histograming and fitting of amplitude spectra)spectra)

o Signal fitting (optimization of parameters Signal fitting (optimization of parameters for tail cancellation)for tail cancellation)

• Reconstruction per fileReconstruction per file

Offline Reconstruction Offline Reconstruction (Tracking)(Tracking)

• ESDESDo AliESDs.root(Default mode)AliESDs.root(Default mode)

• + In calibration mode+ In calibration modeo Full TPC track storedFull TPC track stored

• Clusters belonging to trackClusters belonging to track• Extrapolation point at each pad row Extrapolation point at each pad row

intersection (position, angle, estimated intersection (position, angle, estimated uncertainty, estimated shape parameters)uncertainty, estimated shape parameters)

Calibration: Parameterization of space point Calibration: Parameterization of space point resolution and shape resolution and shape

Offline analysisOffline analysis

• Gain measurementGain measurement• Space point resolution, response Space point resolution, response

function function • Signal fitting, processingSignal fitting, processing• CalibrationCalibration

Offline analysisOffline analysis

• Input dataInput datao Tracks and clusters – chain of Tree of tracks Tracks and clusters – chain of Tree of tracks

• TPCtracks.rootTPCtracks.root

o Pedestal & noise – chain of tree of fitted Pedestal & noise – chain of tree of fitted parameters histogram of amplitude spectra parameters histogram of amplitude spectra (mean –pedestal estimation, sigma – noise (mean –pedestal estimation, sigma – noise estimation) estimation) • TPCsignal.rootTPCsignal.root

o Signal shape – chain of tree with fitted signals Signal shape – chain of tree with fitted signals (parameters of fit, graphs and position (sector, (parameters of fit, graphs and position (sector, pad, row))pad, row))• FitSignal.rootFitSignal.root

AnalysisAnalysis

• .L TestAnalisys.C.L TestAnalisys.C• AddChains(runNumber);AddChains(runNumber);

o Loop over all files with given run number add trees to Loop over all files with given run number add trees to the chain the chain

• Select();Select();o Make default selectionMake default selectiono Example:Example:

• Track.fN>60 && abs(Track.fP4)<0.001Track.fN>60 && abs(Track.fP4)<0.001• Number of cluster per track bigger than 60, remove Number of cluster per track bigger than 60, remove

tracks with big curvature (most probably delta electrons)tracks with big curvature (most probably delta electrons)

• Do predefined plotsDo predefined plotso See following slidesSee following slides

• Analysis done per runAnalysis done per run

Noise AnalysisNoise Analysis

• NoiseSector(“Sector==3”,”Run 872 NoiseSector(“Sector==3”,”Run 872 sector 3 (V(A3_IROC) =1400 V)sector 3 (V(A3_IROC) =1400 V)

Noise analysisNoise analysis

Gain analysisGain analysis

• Statistic not sufficient for pad by pad Statistic not sufficient for pad by pad calibrationcalibration

• 3 default plot3 default ploto Gain as function of pad-rowGain as function of pad-rowo Gain as function of pad position (phi Gain as function of pad position (phi

angle)angle)o Gain as function of z position (electron Gain as function of z position (electron

capture)capture)

Gain analysis (run872)Gain analysis (run872)

• ProfileMaxRow(“Cl.fDetector==49”, “Sector 49”,100)ProfileMaxRow(“Cl.fDetector==49”, “Sector 49”,100)o Arguments: cut, comment, binningArguments: cut, comment, binning

Gain analysis (run872)Gain analysis (run872)

Gain – Run 567Gain – Run 567

Gain – Run 568Gain – Run 568

Gain analysisGain analysis

• ProfileMaxPhi(“Cl.fDetector==49”, “Sector 49”,25)ProfileMaxPhi(“Cl.fDetector==49”, “Sector 49”,25)o Arguments: cut, descriptor, binningArguments: cut, descriptor, binning

Gain analysisGain analysis

Gain - electron capture Gain - electron capture (run 567)(run 567)

• The Q total (Total charge in the cluster) as function of Z position The Q total (Total charge in the cluster) as function of Z position o Relative decrease ~7 % (mainly due to electron capture + Relative decrease ~7 % (mainly due to electron capture +

threshold effect) on full TPC drift (bigger statistic needed to be threshold effect) on full TPC drift (bigger statistic needed to be not influenced by Landau fluctuationnot influenced by Landau fluctuation

Response functionResponse function

• PRFYZ(cut, “Run 872”)PRFYZ(cut, “Run 872”)o Arguments : selection, commentArguments : selection, comment

Response functionResponse function

• PRFZZ(cut, “Run 872”)PRFZZ(cut, “Run 872”)o Arguments : selection, commentArguments : selection, comment

Space ResolutionSpace Resolution

• Left side Run 872Left side Run 872o Command ResYZ(cutinner, cutouter, comment)Command ResYZ(cutinner, cutouter, comment)

• Right side Run 567Right side Run 567

Signal processingSignal processing

• Signal fitting added to analysis chain Signal fitting added to analysis chain to tune parameters for tail to tune parameters for tail cancelationcancelationo Plans to include also Bernardo Mota Plans to include also Bernardo Mota

algorithm to estimate tail cancellation algorithm to estimate tail cancellation parametersparameters

Signal processingSignal processing

• The signal fittingThe signal fittingo Fit function – convolution of Gaussian distribution with the sum Fit function – convolution of Gaussian distribution with the sum

of two exponential distributionsof two exponential distributions• Two exponential distributions approximate k/time distributionTwo exponential distributions approximate k/time distribution• Possibility to reduce exponential components Possibility to reduce exponential components

Signal processingSignal processing

• Lambda 0 parameterLambda 0 parameter• Command P3Z(“Sector==3”,”Sector==39”, comment)Command P3Z(“Sector==3”,”Sector==39”, comment)

Signal processing Signal processing (Run872)(Run872)

• Lambda 1 parameterLambda 1 parameter• Command P5Z(“Sector==3”,”Sector==39”, comment)Command P5Z(“Sector==3”,”Sector==39”, comment)

ConclusionConclusion

• Ongoing work on automatization of the Ongoing work on automatization of the analysis chainanalysis chaino Currently ~ 4 hours for analysis chain (mainly due Currently ~ 4 hours for analysis chain (mainly due

data transfer ~ 100 GBy per one run)data transfer ~ 100 GBy per one run)o Will be reduced Will be reduced

• The default histograms and pictures defined The default histograms and pictures defined • Next plan:Next plan:

o Calibration Calibration • Gain calibrationGain calibration• Time offset calibrationTime offset calibration

o AlignementAlignement

ConclusionConclusion