19 July 2005Fabrizio Cei1 Status and Perspectives of MEG software Fabrizio Cei INFN & University of...

19 July 200519 July 2005 Fabrizio CeiFabrizio Cei 11

Status and Perspectives Status and Perspectives of MEG softwareof MEG software

Fabrizio CeiFabrizio CeiINFN INFN && University University ofof Pisa Pisa

On behalf of the MC/Offline groupOn behalf of the MC/Offline group

MEG Review MeetingMEG Review MeetingPSI, 19 July 2005PSI, 19 July 2005


OutlineOutline

MC status and perspectivesMC status and perspectives

Offline status, perspectives Offline status, perspectives and milestonesand milestones

Rough Estimates of CPU/data Rough Estimates of CPU/data storage needsstorage needs

Contributions: Contributions: TokyoTokyo, , PisaPisa, , LecceLecce,, PSI PSI, , RomaRoma and and PaviaPavia groups. groups.


MC status & MC status & perspectivesperspectives

• MEGEVE - Event GeneratorMEGEVE - Event Generator• GEMGEM – The detector simulator– The detector simulator

– Liquid Xenon CalorimeterLiquid Xenon Calorimeter– Drift ChamberDrift Chamber– Timing CounterTiming Counter– Magnet and TargetMagnet and Target

• ZEBRA Output and Analysis ToolsZEBRA Output and Analysis Tools• LP/Beam Test fully simulated LP/Beam Test fully simulated (not (not

discussed)discussed)

ContributorsContributors:: S. Yamada, P. Cattaneo, F. Cei, W. Ootani, H. Nishiguchi S. Yamada, P. Cattaneo, F. Cei, W. Ootani, H. Nishiguchi et al.et al.


Energy release in LXeEnergy release in LXe

Positron trackPositron track

Hits on TCHits on TC


MEGEVE: the event MEGEVE: the event generatorgenerator

• StatusStatus– Signal eventsSignal events– Michel positronsMichel positrons– Radiative decayRadiative decay

• Exact formulae for unpolarized muonExact formulae for unpolarized muon• Approximation for polarized muon (back-to-back, PApproximation for polarized muon (back-to-back, Pe e P P 52.8 52.8

MeV)MeV)– AIFAIF

• Preliminary AIF within targetPreliminary AIF within target• Started study for realistic AIF: magnet, DCH, TC and TargetStarted study for realistic AIF: magnet, DCH, TC and Target

– Scheme to generate pile-up eventsScheme to generate pile-up events• (Michel + RD, Michel + AIF, AIF + RD, RD + RD) + additional (Michel + RD, Michel + AIF, AIF + RD, RD + RD) + additional Michel decays; more than two events can be overlaidMichel decays; more than two events can be overlaid• time difference distribution inserted: flat with user-defined rangetime difference distribution inserted: flat with user-defined range

• NextNext– Exact formulae for polarized muon’s radiative decayExact formulae for polarized muon’s radiative decay– Realistic AIF and background studies (under way)Realistic AIF and background studies (under way)– Estimate disk space requirements for MCEstimate disk space requirements for MC– Study of online (or semi-online ?) pre-selection and calibrationsStudy of online (or semi-online ?) pre-selection and calibrations– ......


Background studies under Background studies under way 1)way 1)

Accidental background from superimposition Accidental background from superimposition of a Michel positron and a of a Michel positron and a from radiative from radiative decay. decay.

Simulation of Simulation of trigger trigger conditionsconditions quoted in the quoted in the Proposal Proposal

– Photon energy cut Photon energy cut EE > 45 > 45 MeVMeV

– Time window eTime window e++ - - △T = 10 △T = 10 nsns

– ee++- - direction matching direction matchingPreliminary WorkPreliminary WorkE (MeV)E (MeV)

(Y. Hisamatsu (Y. Hisamatsu et al.et al.))


Background studies under way Background studies under way 2)2)

Realistic studies of Michel positron annihilation in Realistic studies of Michel positron annihilation in flight. flight.

Almost complete detector simulationAlmost complete detector simulation (not the target only) (not the target only)Main contributionsMain contributions from from targettarget and and drift chambersdrift chambers..

Annihilation Annihilation energy spectrum in LXe energy spectrum in LXe

Preliminary WorkPreliminary Work

(H. Nishiguchi)(H. Nishiguchi)


Detector simulation 1) Detector simulation 1) LXeLXe

• StatusStatus– GeometryGeometry

• revised shape for vacuum vessel, PMT holders and honeycombrevised shape for vacuum vessel, PMT holders and honeycomb– Implemented decay curve of Liquid Xenon ScintillationImplemented decay curve of Liquid Xenon Scintillation– GEANT based ray trackingGEANT based ray tracking

• Reflection on PMT quartz window and PMT holdersReflection on PMT quartz window and PMT holders• PMT quartz window transmittancePMT quartz window transmittance• Absorption and scattering in Liquid XenonAbsorption and scattering in Liquid Xenon

– OutputsOutputs• Energy deposit, position and timing in Liquid XenonEnergy deposit, position and timing in Liquid Xenon• Preliminary waveform output: hit timing of scintillation photonsPreliminary waveform output: hit timing of scintillation photons for each PMT (for each PMT ( ～～ 3 x 103 x 104 4 photoelectronsphotoelectrons))

• NextNext– Update geometry to match the final designUpdate geometry to match the final design– Implement support structureImplement support structure– ““Fast” scintillation photon tracking; multiple options ? (GNEXT/hand Fast” scintillation photon tracking; multiple options ? (GNEXT/hand

made)made)


Detector simulation 2) Detector simulation 2) DCHDCH


• Helium bag turned off by defaultHelium bag turned off by default• Implementation of the Vernier padImplementation of the Vernier pad

– Isochrones tables for various B-fieldIsochrones tables for various B-field– OutputsOutputs

• Entrance/Exit position from cellsEntrance/Exit position from cells• Energy, timing and direction for each hitEnergy, timing and direction for each hit• Digitized hit timing, charge on wireDigitized hit timing, charge on wire• Drift time in cellsDrift time in cells

• NextNext - Update geometry for latest DCH support and peripherals- Update geometry for latest DCH support and peripherals - Implement charge simulation on both ends & Vernier pads - Implement charge simulation on both ends & Vernier pads effects on output signalseffects on output signals - Implement pulse simulation on wires and pads - Implement pulse simulation on wires and pads


Detector simulation 3) Detector simulation 3) TCTC


• scintillation bars/fibers, PMTs, APDs and light guidesscintillation bars/fibers, PMTs, APDs and light guides– OutputsOutputs

• Hit position, timing and energyHit position, timing and energy• Energy release and step length for each GEANT hit Energy release and step length for each GEANT hit • Preliminary waveform outputs for scintillation barsPreliminary waveform outputs for scintillation bars

– Photon propagation inside the Photon propagation inside the -bars recently implemented-bars recently implemented• NextNext

– Implement support structureImplement support structure– Waveform for scintillation fibersWaveform for scintillation fibers

- A standalone MC for comparison with scintillation bar beam test- A standalone MC for comparison with scintillation bar beam test


Detector simulation 4) Detector simulation 4) Target and MagnetTarget and Magnet

• StatusStatus

- Preliminary approach outside GEM- Preliminary approach outside GEM

- Realistic treatment of target geometry included in GEM- Realistic treatment of target geometry included in GEM• NextNext

– Implement target supportImplement target support– Beam transport within the detectorBeam transport within the detector


ZEBRA Output & Analysis ZEBRA Output & Analysis ToolsTools

• HitsHits– Energy deposit, position and timing for LXe/DCH/TCEnergy deposit, position and timing for LXe/DCH/TC– Scintillation photon hits for LXe PMTScintillation photon hits for LXe PMT

• Preliminary waveform outputPreliminary waveform output

- Brute force approach: record - Brute force approach: record all hit timing for each PMT (LXe)all hit timing for each PMT (LXe)

3 x 103 x 1044 photons @ 500 PMTs/828 PMTs for 52.8 MeV gamma photons @ 500 PMTs/828 PMTs for 52.8 MeV gamma

⇒ ⇒ 120 kB/event (w/ zero suppression); few kB/event from 120 kB/event (w/ zero suppression); few kB/event from TC;TC;

- Need binned waveforms to save disk space - Need binned waveforms to save disk space • Event cocktail (MC & Data)Event cocktail (MC & Data)

- - Prototype for “Bartender” based on ROME in progressPrototype for “Bartender” based on ROME in progress • Analysis toolsAnalysis tools -- ZEBRA2NTUPLEZEBRA2NTUPLE - - ZEBRA2ROOTZEBRA2ROOT – based on – based on ROMEROME; temporary software ; temporary software waiting for waiting for

MegRootMegRoot


The MEG “Bartender” 1)The MEG “Bartender” 1)

• Read Read experimentalexperimental and and simulation datasimulation data..

• Make mixture of several Make mixture of several MC sub eventsMC sub events..

• Simulation of pulse Simulation of pulse shape of MC datashape of MC data..

• Rearrange channels of Rearrange channels of experimental data to experimental data to make them as MC.make them as MC.

• Simple calibrationSimple calibration could could be done.be done.

• Trigger simulationTrigger simulation could could be done.be done.

(R. Sawada)(R. Sawada)


The MEG “Bartender” 2)The MEG “Bartender” 2)

+ =Nphe = 620Nphe = 620Nphe = 123Nphe = 123

Example: Example: waveform pile-upwaveform pile-up

three possible three possible models of single waveformmodels of single waveform;; gaussiangaussian, , sinusoidalsinusoidal or or constant noiseconstant noise can be added; can be added; event rateevent rate can be specified; can be specified; relative timingrelative timing is extracted randomly. is extracted randomly.


Offline statusOffline status

MegRootMegRoot- First version recently released- First version recently released

- - BackboneBackbone is from is from AliRootAliRoot

- Copyrights issues solved with F. Carminati- Copyrights issues solved with F. Carminati

- Included algorithms: - Included algorithms: Alice, GEM Alice, GEM oror proprietary proprietary

- - 4 Modules, 344 Classes, > 4000 Methods4 Modules, 344 Classes, > 4000 Methods

Other topicsOther topics - - Promising pattern recognition and trackingPromising pattern recognition and tracking

algorithms algorithms under development (not discussed)under development (not discussed)


ContributorsContributors

• Main ArchitectureMain Architecture: Alice collaboration, : Alice collaboration, V. Di V. Di BenedettoBenedetto

• MagnetMagnet: : E. CavalloE. Cavallo, W. Ootani, W. Ootani• DCHDCH: C. Chiri, : C. Chiri, F. IgnatovF. Ignatov, M. Schneebeli, S. , M. Schneebeli, S.

Spagnolo, Spagnolo,

G. TassielliG. Tassielli, H. Nishiguchi, H. Nishiguchi• LXeLXe: : V. Di BenedettoV. Di Benedetto, S. Mihara , R. Pazzi, R. , S. Mihara , R. Pazzi, R.

Sawada, Sawada,

G. Signorelli, G. Signorelli, G. TerraccianoG. Terracciano• TCTC: : G. SiragusaG. Siragusa• Event Generator for VMCEvent Generator for VMC: F. Cei, : F. Cei, A. MazzacaneA. Mazzacane• DatabaseDatabase: : D. BarbareschiD. Barbareschi, R. Sawada, R. Sawada

Blue: Blue: young people who recently joined the collaborationyoung people who recently joined the collaboration


MegRoot ArchitectureMegRoot Architecture

• MegRoot FrameworkMegRoot Framework– Based on Based on ROOTROOT– User code in User code in C++C++– Usage of Usage of FORTRAN librariesFORTRAN libraries

• Geant3, event generators, “microcernlib”Geant3, event generators, “microcernlib”

• Integrates reconstruction and analysis Integrates reconstruction and analysis softwaresoftware

• Each detector subsystem has one single Each detector subsystem has one single packagepackage

(one directory, one library)(one directory, one library)• Calibration constants read via Calibration constants read via MySQLMySQL

interfaceinterface


MegRoot statusMegRoot status

• The The structurestructure of of all Classesall Classes is is completecomplete up to the up to the Digitization stepDigitization step

(main purpose is to (main purpose is to test the Reconstruction Modulestest the Reconstruction Modules))• All All MethodsMethods have been have been designeddesigned and and most algorithmsmost algorithms

have have been been implementedimplemented• The The Reconstruction ClassReconstruction Class is currently is currently being designedbeing designed• Reconstruction Class will read out Reconstruction Class will read out ROOT ObjectsROOT Objects ((MC DigitsMC Digits) or ) or streamer objectsstreamer objects ( (raw dataraw data))• Intense collaborationIntense collaboration between Detector Experts and between Detector Experts and Core Offline Group under wayCore Offline Group under way• Sofware WorkshopSofware Workshop in Lecce (21 - 22 June) in Lecce (21 - 22 June) very successfulvery successful (several proposals and new ideas)(several proposals and new ideas)• Lecce people are Lecce people are joining the effort to bring the LP code joining the effort to bring the LP code

withinwithin MegRoot and analyze the dataMegRoot and analyze the data with the rest of the with the rest of the

collaborationcollaboration


What’s missing in What’s missing in MegRootMegRoot

• Waveform decodingWaveform decoding • Detailed structure of the Detailed structure of the Reconstruction Reconstruction

classclass• MySQL interfaceMySQL interface needs to be extended to needs to be extended to

the the finalfinal Detector Detector (presently it (presently it only works only works for LPfor LP))

• Calibration ModuleCalibration Module• Farm Manager CodeFarm Manager Code ( (Global/LocalGlobal/Local))• Not final geometry Not final geometry (to be borrowed from (to be borrowed from

GEM)GEM)

It could be one of the It could be one of the most CPU consuming most CPU consuming

processesprocesses


Offline MilestonesOffline Milestones

• LP in MegRoot: LP in MegRoot: ongoing, analysis within ongoing, analysis within OctoberOctober

• CVSCVS: : September 2005September 2005 • Reconstruction ClassReconstruction Class: : October 2005October 2005 • Estimate LXe shower analysis CPU loadEstimate LXe shower analysis CPU load: :

October 2005October 2005• Estimate WF feature extraction CPU loadEstimate WF feature extraction CPU load: :

December 2005December 2005• Calibration ModuleCalibration Module: it will start in : it will start in

November 2005November 2005 (after completion of (after completion of Reconstruction Class)Reconstruction Class)


Rough estimates of Rough estimates of CPU/data storage needsCPU/data storage needs

• ““00thth order” approximation order” approximation - - MC productionMC production• GEANT3 simulationGEANT3 simulation• Hit production & digitizationHit production & digitization

- - Data/MC reconstructionData/MC reconstruction (partial) (partial)• Computations based on Computations based on Pentium IIIPentium III, , 1.4 GHz1.4 GHz (faster computers available)(faster computers available)• Data reconstructionData reconstruction

– LXeLXe: LP beam test data; QSUM, Linear Fit and MINUIT fit: LP beam test data; QSUM, Linear Fit and MINUIT fit– DCHDCH: Kalman Filter to 5 simulated charged tracks & : Kalman Filter to 5 simulated charged tracks & Track extrapolation to TC (1.2 x storage and 1.5 x Track extrapolation to TC (1.2 x storage and 1.5 x

CPU)CPU) - - TCTC: Not implemented: Not implemented

• Waveform decoding not implementedWaveform decoding not implemented


CPU estimates CPU estimates (msec/evt) 1)(msec/evt) 1)

Hits + DigitsHits + Digits

productionproductionReconstructionReconstruction

Montecarlo events Montecarlo events generation generation

2000 – 60002000 – 6000

DCH reconstructionDCH reconstruction 200 200 (MC) (MC)

LXe reconstructionLXe reconstruction 40 – 80 40 – 80 (LP data)(LP data)

TC reconstructionTC reconstruction not includednot included

TotalTotal 2000 – 60002000 – 6000 250 – 300250 – 300


CPU estimates 2)CPU estimates 2)• AssumptionsAssumptions::

– Trigger rate: Trigger rate: 20 Hz 20 Hz (physical events)(physical events)- - MC:MC:

- - 101012 12 accidental events obtained by “Event Cocktail”accidental events obtained by “Event Cocktail” ((101066 Michel positrons & Michel positrons & 101066 AIF/RD photons)/year; AIF/RD photons)/year; Reconstruct ~ 10Reconstruct ~ 1088 events events & use others for occupancy & use others for occupancy

checks;checks;- - 2 x 102 x 1077 correlated events in the signal region/year. correlated events in the signal region/year.

• Results:Results:

- - Montecarlo productionMontecarlo production & event cocktail: & event cocktail: 10 10 30 30 CPUCPU

- - MC/Raw data ReconstructionMC/Raw data Reconstruction: : >> 20 20 CPU/proc.CPU/proc.

- WF decoding not implemented; - WF decoding not implemented;

- Calibrations to be estimated;- Calibrations to be estimated;

- No pre-filtering - No pre-filtering (it could (it could reduce CPU timereduce CPU time))..


Data Storage Estimate Data Storage Estimate 1)1)

REAL DATAREAL DATAAssume 0.5 x 10Assume 0.5 x 107 7 sec/year & an overall trigger rate of sec/year & an overall trigger rate of 100 Hz, 100 Hz, 20 Hz20 Hz of of physical dataphysical data and and 80 Hz80 Hz of of calibrationscalibrations;; Waveform data (channel occupancy assumed: 50 % Waveform data (channel occupancy assumed: 50 % for for Lxe, 10 % for DCH & TC): Lxe, 10 % for DCH & TC): 1.2 Mb/event 1.2 Mb/event 120 120 Mb/secMb/sec;; Compression factorsCompression factors: : 10 for true events10 for true events (obtained in PIBETA); (obtained in PIBETA); 100 for calibrations100 for calibrations 0.12 Mb/event for 0.12 Mb/event for physical physical events, 0.012 Mb/event for calibrationsevents, 0.012 Mb/event for calibrations

Data storageData storage: (20 x 0.12 + 80 x 0.012) Mb/sec = : (20 x 0.12 + 80 x 0.012) Mb/sec = 3.4 3.4

Mb/secMb/sec

3.4 Mb/sec x 0.5 x 103.4 Mb/sec x 0.5 x 1077 sec/year = sec/year = 17 17

Tbyte/yearTbyte/year



MONTE CARLOMONTE CARLO Assume a total production of Assume a total production of 10101212 accidental events accidental events (dominant(dominant background in the signal window) and background in the signal window) and 2 x 102 x 1077 correlated correlated events/yearevents/year; first sample obtained by merging ; first sample obtained by merging two 10two 1066 independent samplesindependent samples of positrons & photons; to reduce of positrons & photons; to reduce problems problems of multiple disk accesses, MC events must be duplicated of multiple disk accesses, MC events must be duplicated ((x 2 correlated, x 20 accidentalx 2 correlated, x 20 accidental). ). Event size based on storing photon arrival times on LXe: Event size based on storing photon arrival times on LXe: 200 kb/event200 kb/event; waveforms not simulated and noise not ; waveforms not simulated and noise not included. included. Data storageData storage: : - - (200 kb/event x 2 x 10(200 kb/event x 2 x 1077 x 2) = x 2) = 8 Tb/year8 Tb/year (correlated (correlated events);events);

- - (200 kb/event x 2 x 10(200 kb/event x 2 x 1066 x 20) = x 20) = 8 Tb/year8 Tb/year (uncorrelated (uncorrelated events); + factor 2 overhead for events); + factor 2 overhead for storing informationstoring information of of

most significant eventsmost significant events: : TOTAL ~ 30 TOTAL ~ 30 Tb/yearTb/year



SummarySummary

Real data: Real data: 17 Tbytes/year17 Tbytes/yearMonte Carlo: Monte Carlo: 30 Tbytes/year 30 Tbytes/yearOverhead Overhead (DSTs, reconstructed info …) (DSTs, reconstructed info …) ~ 15 ~ 15 Tbytes/yearTbytes/year____________________________________________________________________________________Total Total ~ 60 Tbytes/year~ 60 Tbytes/year


ConclusionsConclusions

Relevant progressesRelevant progresses were obtained in were obtained in MCMC and and offline frameworkoffline framework;; About About 10 young people joined the collaboration10 young people joined the collaboration in the in the

offline coreoffline core group; the group; the MC groupMC group is also in expansionis also in expansion; ; A A first version of Offline frameworkfirst version of Offline framework was released was released; ;

important milestonesimportant milestones were defined for the Offline group; were defined for the Offline group; Other software jobs are under wayOther software jobs are under way: : trackingtracking and and patternpattern

recognitionrecognition algorithms, studies of possible algorithms, studies of possible calibration procedurescalibration procedures … … Thanks to the Thanks to the experience gained in the beam testexperience gained in the beam test and to the and to the

good level of sophistication reached by the MC codegood level of sophistication reached by the MC code we are we are

in a position to in a position to perform a first (“0perform a first (“0thth order”) estimate order”) estimate of of

CPU powerCPU power and and disk storage needsdisk storage needs of our experiment. of our experiment. We are starting to We are starting to think at physics analysisthink at physics analysis ( (likelihood, blindlikelihood, blind …) …)


Backup slidesBackup slides


MegRoot structureMegRoot structure

MegRooMegRoott

run management interface classes detector base classes data structure base classes

Detectors DCH LXE

FMDTC

STEER

PYTHIA6

Geant3

MICROCERN

Geant4ROOT

HIJING …EVGEN

Geant3 VMCGeant4 VMCExternalExternalpackagepackage

ss

VMC


RemarksRemarks

• One big contribution One big contribution missing: WF feature missing: WF feature extractionextraction

• Montecarlo has space for improvementMontecarlo has space for improvement• Offline needs to implement more Offline needs to implement more

realistic algorithms for LXe realistic algorithms for LXe reconstructionreconstruction

• Fast data transmission protocol needed Fast data transmission protocol needed because many nodes will access few because many nodes will access few disksdisks..


DataflowDataflow

Online Disk

Server

3.4 3.4 MB/secMB/sec

Offline Disk

Server

0.35 MB/secDAQ

Hits-Digits

producion

3.75 3.75 MB/secMB/sec

0.35 MB/secReconstruction

Farm

Reconstruction

Farm

MCMCDatDataa

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19 July 2005Fabrizio Cei1 Status and Perspectives of MEG software Fabrizio Cei INFN & University of...

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