C. Oppedisano

C. Oppedisano, 8 July 2008, ALICE Offline Week 1

OUTLINEOUTLINE

• GeometryGeometry

• Raw data Raw data

• Detector algorithmsDetector algorithms

• Shuttle preprocessor and OCDBShuttle preprocessor and OCDB

• ReconstructionReconstruction

• ESDESD

• classes for QAclasses for QA


GEOMETRY

AliZDCv3 ZDCs on both sides implemented (in previous version only side C was there) Beam pipe geometry on side A finalized with the implementation of the recombination chamber placed before the ZDC location Overlaps/extrusions corrected (thanks to Andreas!)

Side A geometry @ ZDC location

RECOMBINATION CHAMBERZPA

ZNA

MACHINE LUMINOMETER ALICE IP

Full geometry when ZDC is initialized in AliRoot geometry

ZDCside C

ZDCside A

ALICE barrel

230 m


Relevant change in the code

“THE CHANGE” Before commissioning “static” mapping of ADC channels was foreseenDuring the commissioning need to change the signal cabling into ADC modules, possibility to add a module...

the cabled channels and the corresponding physics signals written together with the raw data (in the StartOfData event)

Dump of StartOfData event:*****************************************DUMP OF SOR EVENT 0 0xff000000 1 0x00000118 GEO: 0 type: 1 channels: 24 2 0x00000002 ch 0: kZNAC 3 0x80000002 ch 0: kZNAC Low range 4 0x00010003 ch 1: kZNA1 5 0x80010003 ch 1: kZNA1 Low range 6 0x00020004 ch 2: kZNA2 7 0x80020004 ch 2: kZNA2 Low range

the mapping is directly read from raw data by the DAs that run on the LDC and are written in the OCDB

from raw data to DAs into OCDB objects through the Shuttle preprocessor...

module geographic address + no. of cabled signal

channel + physics signal (ZNA - tower 1)


RAW DATA

AliZDCRawStream class updated decoding of StartOfData event (accessible from DAs that run on LDC)

Other features added to the class: reading of the CDH block attributes providing the run type in STANDALONE runs L1 trigger message: test of the software calibration bit (the data format is different in PHYSICS runs and in STANDALONE CALIBRATION runs) test the read-out card messages and use flags to decide if the events (sub-events) are correctly written

scaler decoding implemented (used mainly to count trigger rates)

Test on simulated/real raw data is under way

The “original” class has already been used to read all the calibration data collected during the commissioning of the hadronic ZDCs


DAs & OBJECTS IN OCDB

p-p

RUN TYPE STANDALONE_PEDESTAL STANDALONE_LASER

DA writes parameters for pedestal subtraction from ADC spectra

writes values measured by the reference PMTs

OCDB AliZDCPedestal object AliZDCLaserCalib object

Pb-Pb

RUN TYPE STANDALONE_PEDESTAL STANDALONE_EMD STANDALONE_LASER

DA writes parameters for pedestal subtraction from ADC spectra

writes energy + relative calibration factors

writes values measured by the reference PMTs

OCDB AliZDCPedestal object AliZDCCalib object AliZDCLaserCalib object

In every run the mapping of the cabled ADC channels and the physics signal is read and can be written (if changed!) in the OCDB AliZDCChMap object

We have very different needs/aims in p-p and in A-A!!!

ZDCs don’t provide triggers, no trivial way to provide energy calibration

ZDC trigger detectors, centrality variables reconstruction, energy calibration from physics measurement


DAs (I)

The DAs have been updated/implemented according to the changes introduced in AliZDCRawStream class 4 DAs implemented

ZDCPEDESTALda.cxx RUN type: STANDALONE_PEDESTAL input: 96 1-dim. histos + 48 2-dim histos + StartOfData event for the mapping output: ZDCPedestal.dat ASCII file containing 144 pairs of floats:

48 pairs of float for in-time signals mean value + 48 pairs of float for out-of-time signals mean value + 48 pairs of parameters from fit of the correlation in-time vs. out-of-timeZDCChMapping.dat ASCII file with the mapping of the ADC modules

ZDCLASERda.cxx RUN type: STANDALONE_LASER input: 2 1-dim. histos from the reference PMTs used to check the signal stability + StartOfData event for the mapping needs: ZDCPedestal.dat as input output: ZDCLaser.dat ASCII file containing:

4 pairs of float for reference signals mean value + ZDCChMapping.dat ASCII file with the mapping of the ADC modules


DAs (II) ZDCEMDda.cxx RUN type: STANDALONE_EMD input: 28 1-dim. histos from EM dissociation events StartOfData event for the mapping needs: ZDCPedestal.dat as input output: ZDCEMDCalib.dat ASCII file containing:

4 pairs of float for in-time reference signals mean value + ZDCChMapping.dat ASCII file with the mapping of the ADC modules

NOTES no energy calibration from data foreseen for the EM calorimeter!!!! in p-p there is no DIRECT way to extrapolate energy calibration factors from data for p-p data initially factor calibration = 1 will be used!

ZDCMAPPINGda.cxx RUN type: all the others input: StartOfData event output: ZDCChMapping.dat ASCII file with the mapping of the ADC modules

Final tests going on before re-starting the validation procedure

ONLY IN Pb-Pb!!!


SHUTTLE PREPROCESSOR (I)

AliZDCPreprocessor updated

PROCESSED RUN TYPES FXS FILE TO BE RETRIEVED

STANDALONE_PEDESTAL ZDCPedestal.dat, ZDCChMapping.dat STANDALONE_EMD ZDCEMDCalib.dat, ZDCChMapping.dat STANDALONE_LASER ZDCLaserCalib.dat, ZDCChMapping.dat any other run tpe ZDCChMapping.dat

For ALL RUN types:

DCS position of the 4 hadronic ZDCs alignment object in OCDB

DAQ ADC channel/physics signal mapAliZDCChMapping

calibration object in OCDB


SHUTTLE PREPROCESSOR (II)

For the other RUN TYPES the above specified files in DAQ FXS are processed a calibration object is written in the OCDB depending on the RUN type:

STANDALONE_PEDESTAL Calib/Pedestals AliZDCPedestals objectSTANDALONE_LASER Calib/LaserCalib AliZDCLaserCalib object STANDALONE_EMD Calib/Calib AliZDCCalib object (in Pb-Pb) In p-p runs, the calibration coefficients are set to 1 WITHOUT processing any FXS file

Shuttle test setupSuccesfully tested for the already implemented RUN TYPES (STANDALONE_PEDESTAL and STANDALONE_EMD)

Production @ P2If the DCS DP are found in the DCS DB, they are correctly processed! Unfortunately at the moment the DCS DP aren’t always written DCS problem, experts investigating!


CALIBRATION OBJECTS (I)AliZDCChMapping object containing the mapping of the ADC modules and the corresponding physics signals (needed in reconstruction) data members Int_t fADCModule[48]; // ADC module Int_t fADCChannel[48]; // ADC channel Int_t fDetector[48]; // detector Int_t fSector[48]; // sector

AliZDCPedestal calibration object giving parameters for pedestal subtraction from ADC spectra data members Float_t fMeanPedestal[48]; // Mean pedestal values Float_t fMeanPedWidth[48]; // Mean pedestal widths Float_t fOOTPedestal[48]; // "Out of Time" pedestal values Float_t fOOTPedWidth[48]; // "Out of Time" pedestal widths Float_t fPedCorrCoeff[2][48]; // Fit of correlation in-time vs. out-of-time

AliZDCLaserCalib calibration object to correct for aging or damaging effects, monitored by means of 2 reference PMTs (1 per side) data members Float_t fRefPMSignal[2]; // RefPM signal mean values Float_t fRefPMSignalWidth[2]; // RefPM signal width


CALIBRATION OBJECTS (II)

AliZDCCalib (only for Pb-Pb data)

E calibration factors from EM dissociation events the conversion factor ADC channels Energy can be calculated from the fit of 1 neutron (proton) peak in ZN (ZP) spectrum

relative calibration coefficients for the 5 PMTs of each hadronic ZDC from EM dissociation events algorithm for the relative calibration of the 4 tower PMTs tested on simulated data the sum of the 4 calibrated tower PMTs is then equalized w.r.t. the “common” PMT

data members // --- E calibration Float_t fEnCalibration[6]; // Coeff. for energy calibration // --- Coefficients for tower calibration Float_t fZN1EqualCoeff[5]; // Equalization coefficients for ZN1 PMTs Float_t fZP1EqualCoeff[5]; // Equalization coefficients for ZN1 PMTs Float_t fZN2EqualCoeff[5]; // Equalization coefficients for ZN1 PMTs Float_t fZP2EqualCoeff[5]; // Equalization coefficients for ZN1 PMTs

Simulated spectrum of EMD events

2.7 5.4 8.1 10.8 E (TeV)

ZN1ZN2ZN3ZN4ZNC

ZN fibres connection


RECONSTRUCTIONAliZDCReconstructor class

2 different algorithms implementedAliZDCReconstructor::ReconstructEventpp AliZDCReconstructor::ReconstructEventPbPb

RECONSTRUCTION STEP CALIBRATION OBJECT USED

p-p pedestal subtraction AliZDCPedestal object from OCDB signal equalization [AliZDCCalib +] AliZDCLaserCalib from OCDB signals summed

Pb-Pb pedestal subtraction AliZDCPedestal object from OCDBsignal equalization AliZDCCalib + AliZDCLaserCalib from OCDBenergy calibration AliZDCCalib object from OCDBsignals summedcentrality variables reco AliZDCRecoParamPbPb class

crucial to know the BEAM TYPE during reconstruction to select the algorithm waiting for the “official” decision, for the moment p-p reconstruction has been forced in AliZDCReconstruction


AliZDCRecoParam

AliZDCRecoParam base class and 2 derived classes implemented:

AliZDCRecoParampp data memberFloat_t fBeamEnergy; // beam energy

AliZDCRecoParamPbPb containing functions/parameters used to reconstruct the centrality variables (Nspec, b) from the measured energies some of the data members// *** PARAMETERS FOR Pb-Pb COLLISIONS // --- Functions to evaluate centrality variables from defined functions TF1* fZNCen; //! Nspectator n true vs. EZN TF1* fZNPer; //! Nspectator n true vs. EZN TF1* fZPCen; //! Nspectator p true vs. EZP TF1* fZPPer; //! Nspectator p true vs. EZP TF1* fZDCCen; //! Nspectators true vs. EZDC TF1* fZDCPer; //! Nspectators true vs. EZDC TF1* fbCen; //! b vs. EZDC TF1* fbPer; //! b vs. EZDC TF1* fZEMn; //! Nspectators n from ZEM energy TF1* fZEMp; //! Nspectators p from ZEM energy TF1* fZEMsp; //! Nspectators from ZEM energy TF1* fZEMb; //! b from ZEM energy // --- Coefficients for centrality selection from ZEM signal Float_t fZEMEndValue; // End point value of ZEM energy spectrum Float_t fZEMCutFraction; // Fraction of ZEM energy spectrum used to cut


ESD (I)

AliESDZDC class data members

EZNA, EZPA, EZNC, EZPC Double32_t fZDCN1Energy; // reconstructed energy in the neutron ZDC Double32_t fZDCP1Energy; // reconstructed energy in the proton ZDC Double32_t fZDCN2Energy; // reconstructed energy in the neutron ZDC Double32_t fZDCP2Energy; // reconstructed energy in the proton ZDC

getters: GetZDCN1Energy(), GetZDCP1Energy(), GetZDCN2Energy(), GetZDCP2Energy()1 and 2 refers respectively to the C (dimuon) and A sides

energy detected in ZEM1 and ZEM2 Double32_t fZDCEMEnergy; // signal in the electromagnetic ZDCs Double32_t fZDCEMEnergy1; // 2nd EM signal, cannot change fZDCEMEnergy to array (not

backward compatible)

getters: GetZDCEMEnergy(i)

in p-p these ESD DO NOT CONTAIN THE ENERGIES!!!BUT signals PROPORTIONAL to the energies (in ADC channel units)


ESD (II) calibrated signal for each PTM of the hadronic ZDCs 5 signal x 4 detectors x 2 gain chains of the ADC = 40 valuesDouble32_t fZN1TowerEnergy[5];// reco E in 5 ZN1 sectors - high gain chain Double32_t fZN2TowerEnergy[5];// reco E in 5 ZN2 sectors - high gain chain Double32_t fZP1TowerEnergy[5];// reco E in 5 ZP1 sectors - high gain chain Double32_t fZP2TowerEnergy[5];// reco E in 5 ZP2 sectors - high gain chain Double32_t fZN1TowerEnergyLR[5];// reco E in 5 ZN1 sectors - low gain chain Double32_t fZN2TowerEnergyLR[5];// reco E in 5 ZN2 sectors - low gain chain Double32_t fZP1TowerEnergyLR[5];// reco E in 5 ZP1 sectors - low gain chain Double32_t fZP2TowerEnergyLR[5];// reco E in 5 ZP2 sectors - low gain chainDouble32_t fZNACentrCoord[2];// Coordinates of the centroid over ZNC Double32_t fZNCCentrCoord[2];// Coordinates of the centroid over ZNA

getters: GetZN1TowerEnergy() and so on…

Moreover the signal of the neutron ZDC is used to reconstruct event by event the centroid of spectator neutrons over the detector front face in order to provide a first order estimate of the reaction plane methods to get the coordinates of the centroid given the number of detected spectators providedDouble32_t * GetZNCCentroid(int NspecnC);Double32_t * GetZNACentroid(int NspecnA);

NpartShort_t fZDCParticipants;// number of participants estimated by the ZDC

getter: GetZDCParticipants() This datum has NO MEANING in p-p!!!


QA histograms - Simulation

AliZDCQADataMakerSim

HITS histograms spectator centroid over neutron ZDCs

DIGITS histograms ZNA(C) and ZPA(C) ADC spectra (ZNA1+ZNA2+ZNA3+ZNA4+ZNC) summed tower PTM signals (ZNA1+ZNA2+ZNA3+ZNA4) signal from common PTM (ZNC)

both for low and high gain chains

ZNA

ZNA

ZN1ZN2ZN3ZN4ZNC

ZN fibres connection to PMTs


QA histograms - Reconstruction

AliZDCQADataMakerRec

RAW histograms ZNA(C) and ZPA(C) raw data ADC spectra summed tower PTMi signals (ZN1+ZN2+ZN3+ZN4) signal from common PTM (ZNC)

both for low and high gain chains

ESD histograms ZNA(C) centroid total energy in the 4 hadronic ZDCs energy in the 4 tower PMTs energy in the common PMTs

ZN side CZP side C


QA checker

AliZDCQAChecker

SIMULATIONHITS check passed if |X(Y) values| < 0.2 cmDIGITS check that ZNA and ZNC have the same mean value @ 1 level

check that ZPA and ZPC have the same mean value @ 3 level check that PMC and i(PMQi) difference < 10%

RAW & ESDSimilar checks to the ones performed on the DIGITS: comparison between total response on the 2 sides check that the sum of the 4 PTMs is comparable with the PMC signal


OPEN TASKS (I)

DAsDAs

From February debugging of the ZDC read-out card to solve unexpected problems (not seen during December runs) that didn’t allow to acquire dataWork still ongoing, from last week we are able to run in STANDALONE mode!!! delay in DA validation

Change in AliZDCRawStream class already validated DAs updated, new DAs implemented re-start the validation procedure (DAQ team warned)

DA STATUS

ZDCPEDESTALda.cxx under debug, to be committed

ZDCLASERda.cxx to be updated and committed

ZDCEMDda.cxx relative PMTs calibration still to be implemented, to be tested and committed

ZDCMAPPINGda.cxx ready to be committed


OPEN TASKS (II)

Shuttle preprocessorShuttle preprocessor

DCS system used in STANDALONE runs only from last week still some problem to be checked (already reported to Chiara and Jan), Grazia Luparello is working on the item with the help of CERN DCS experts

ReconstructionReconstruction

Beam type info needed, waiting for a decision (Cvetan keeps us informed)

DA for ShuttlePostpone the done date to the end of August

AliRoot and condition datawhat are we supposed to do?


Tasks that can be closed?!? List of DCS for Shuttle DCS list for Shuttle was provided to Alberto Colla months ago

http://aliceinfo.cern.ch/Offline/Activities/Shuttle/ZDC_DCS.html

FXS file list the list is ready…

PROCESSED RUN TYPES FXS FILE TO BE RETRIEVED

STANDALONE_PEDESTAL ZDCPedestal.dat, ZDCChMapping.dat STANDALONE_EMD ZDCEMDCalib.dat, ZDCChMapping.dat STANDALONE_LASER ZDCLaserCalib.dat, ZDCChMapping.dat any other run tpe ZDCChMapping.dat

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C. Oppedisano