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Transcript of Simulation Project Overview Gabriele Cosmo, CERN/PH-SFT Simulation Project Leader LHCC...
Simulation Project Overview
Gabriele Cosmo, CERN/PH-SFT
Simulation Project Leader
http://lcgapp.cern.ch/project/simu
LHCC Comprehensive Review of LCG
November 23, 2004
LHCC Review , Nov 2004 Slide 2 Gabriele Cosmo, CERN/PH-SFT
Simulation Project
Simulation framework Interface to multiple simulation engines (Geant4, Fluka) and
geometry models exchange Geant4 team participating
Aligned with and responding to needs from LHC experiments, physics validation, simulation framework
Fluka team participating Framework integration, physics validation
Simulation physics validation subproject Assess adequacy of simulation and physics environment for LHC
and provide the feedback to drive needed improvements Generator services subproject
Generator librarian; common event files; validation/test suite; development when needed (HEPMC, etc.)
WitoldPokorski
JohnApostolakis
AlfredoFerrari
AlbertoRibon
PaoloBartalini
LHCC Review , Nov 2004 Slide 3 Gabriele Cosmo, CERN/PH-SFT
Project Organization
Simulation Project Leader
Framework
WPWP
WP
Geant4
WPWP
WP
Flukaintegration
WPWP
PhysicsValidation
WPWP
WP
ShowerParam
GeneratorServices
WPWP
Subprojects
Work packages
Geant4Project
FlukaProject
ExperimentValidation MC4LHC
LHCC Review , Nov 2004 Slide 4 Gabriele Cosmo, CERN/PH-SFT
Simulation Framework – General goals
Support the physics validation activities and test beam simulations Provide flexible infrastructure for efficient development and for usage of detector
simulation applications Provide means for interchanging geometry descriptions between different
applications Provide flexible, LCG-oriented interfaces to simulation toolkits
Agreed approach: set up a simulation infrastructure based on Geant4 and Fluka via Flugg (which uses the Geant4 geometry)
Existing Geant4 benchmarks/simulation-validation setups can be run with Fluka with minimum effort
Idea of creating a generic framework for Geant4 and Fluka for full detector simulation setups abandoned due to lack of strong interest from the experiments (except for ALICE which has its own solution based on VMC)
Interest in having a common tool to be applied for specific physics validation studies
Geant4/Fluka physics validation will be treated on a case by case basis
LHCC Review , Nov 2004 Slide 5 Gabriele Cosmo, CERN/PH-SFT
Simulation Framework – Status & plans
Complete Geant4+Fluka+Flugg setups to meet physics validation needs First example of usage for test-beam validation studies provided (pixel detector
simulation) New use-case examples to be provided, together with proper documentation and
guidelines. Expected removal of PEMF pre-processing stage in Fluka Extensions to Flugg to meet the best achievable level of automation
Establish a persistent exchange format for geometry descriptions: GDML Development motivated by several use-cases:
Debugging, visualization, XML-based, readability, low-overhead geometry exchange, … Status after recent developments:
Schema complete enough to describe realistic geometries like the LHCb detector The Geant4 reader/writer has been developed and tested on realistic (LHCb) geometries
Immediate plan: Further extend the schema to support more complex geometries (ATLAS and CMS)
Short/Medium term: Implement reader/writer for Root
Developed concrete milestones reflecting the program above The program described makes maximum use of existing work Manpower currently assigned to the project is just 0.5 FTE !
LHCC Review , Nov 2004 Slide 6 Gabriele Cosmo, CERN/PH-SFT
Simulation Framework – Longer Term
Increasing interest from different experiments in Python-based frameworks (because of large flexibility)
LCG tools (LCGDict/PyLCGDict) provide excellent starting point for development/study of ‘pythonized’ simulation applications
First tests (creating LCGDict for Geant4 and running Geant4 via PyLCGDict) look very promising
Geant4 expressed interest in the Python technology Require revision of public interfaces and classes exposure safety LCG tools (Pool/Root) could also be applied as persistency mechanism
Simulation environment Provide a working example of Python based (Geant4) simulation
application using LCGDict and PyLCGDict Investigate the possibility of using LCG persistency framework also for
geometry descriptions
LHCC Review , Nov 2004 Slide 7 Gabriele Cosmo, CERN/PH-SFT
Geant4 in production
Three LHC experiments (ATLAS, CMS, LHCb) now using it successfully in production OSCAR (CMS), Gauss (LHCb) and ATLAS’s Geant4-based simulation programs are the
production tools OSCAR and Gauss have replaced G3 based simulation
Substantial productions (numbers from Oct 20th Application Area Meeting presentations) ATLAS DC2 (summer 2004) produced 12M events Oscar (CMS) : 35 M pp interaction events, and first 100 Pb-Pb events Gauss (LHCb): Over 200 M events simulated
In production use demonstrated low crash rate (and decreasing with new releases) Rate decreasing from 1/10K events (5.2, CMS) to 1 per Million events (6.1, LHCb)
G4 team addressed issues found in test productions
The Geant4 LCG/SI sub-project and the Geant4 Collaboration LCG/SI/G4 responsible for CERN/LHC participation in Geant4 Work plan integrated with overall Geant4 plan
Geometry and tracking in field, Physics: hadronic and electromagnetic, testing and release, coordination
Collaborating closely on validation, infrastructure and robustness With Physics Valid. on validation, and with Framework on geometry exchange Worked on shared infrastructure (testing, portal) with SPI: bonsai, Savannah With experiment simulation and physics teams on robustness, integration and validation
LHCC Review , Nov 2004 Slide 8 Gabriele Cosmo, CERN/PH-SFT
Geant4: 2004 goals
Feb 2004 – Savannah/SPI prototype portal for problem reporting system for Geant4 Prototype and assessment delivered; under evaluation in the Geant4 Collaboration
Mar 2004 - Release 6.1 (Contributions in several areas) focused on improving production usage in LCG experiments
Jun 2004 – Scheduled release 6.2 (Contributions) focused on better use of computing resources, including performance and memory use,
and refinements to specific physics models, persistency and windows support Sep 2004 - Development release
included additional geometry volume registration, refinements to physics models supported CLHEP 1.9, and still compatible with CLHEP 1.8
Oct 2004 - First consolidated acceptance suite for LHC applications Suite of simplified test-beam setups created, and being deployed
Dec 2004 - Release 7.0 (Contributions) Release 7.0 contributions focus on improvement of physics models and additional
geometry functionality Dec 2004 - Prototypes & Process Improvements
prototype 3D string fragmentation; ensure maintenance and improve examples, system tests and physics lists
Dec 2004 - Geant4 validation in LHC production (added May 2004) documenting results, response to feedback, status of production use of Geant4
LHCC Review , Nov 2004 Slide 9 Gabriele Cosmo, CERN/PH-SFT
Geant4: some highlights
Geant4 reliability in production: crash rate low and decreasing CMS (Geant4 5.2, 1 crash per 10,000 events) ATLAS (Geant4 6.0 patch1, ~1 crash per 1 Million events) LHCb (Geant4 6.1, ~1-2 crashes per 1 Million events)
Support and maintenance Addressing issues found in LHC experiment production
providing high job ‘robustness’ (less than ~1 per mille job failures in 6.1, 6.2) Code improvements to help identify problem conditions
In hadronics and geometry (Geant4, releases 6.0 & 6.1) Creation of ‘statistical testing’ suite
Automated physics comparisons in simple test-beam-like setups Being deployed for validation of release 7.0 (December 2004)
Requires significant computer resources New and improved physics models
And improvements in EM & hadronics (Geant4, releases 6.1 & 6.2) Refinements & more functionality in kernel
E.g. enabling experiments to easily construct detectors Reflections, divisions, …
New fast shower capability (a-la GFLASH) Integrating efforts in LHC experiments into Geant4 toolkit
New addition, just scheduled for Geant4, release 7.0
LHCC Review , Nov 2004 Slide 10 Gabriele Cosmo, CERN/PH-SFT
Geant4: potential future goals
Provide continued support and maintenance Address queries on physics, geometry, tracking issues
Solve problems and respond to other issues / reports Sustain existing physics use cases and enable emerging LHC-related uses
Enhance physics Address requirements for sub-1% EM stability and precision Address precision needs for combined calorimetry in full detector simul. / LHC exp. Address issues of pre-calibration using Monte Carlo (ATLAS) Further enable use of radiation studies, addressing needs for data and physics lists
Improve and extend ‘automated’ release validation Extend and refine comparisons
Within available computing resources Address requirements for geometry and improved persistency
Improvements to Boolean solids, to address robustness issues Enable exchange format (GDML) and ‘direct’ persistency (POOL / ROOT) for Geant4
Address new requirements for radiation applications Improve ‘standard’ tallying and extend with additional observables
Continue to improve CPU performance Address hot spots identified in 2004 and bring new tools into use
LHCC Review , Nov 2004 Slide 11 Gabriele Cosmo, CERN/PH-SFT
Geant4: manpower in 2004
Effort currently 9.0 FTE from Staff/ Associates
/Fellows ~1.0 visitors
Expertise and effort are required to address ‘expert’ inquiries
Need to maintain expertise Balance between support/maintenance
and development Increased effort on support and
maintenance New requirements necessitate
refinements & developments. Continuity of effort depends
On the expected continued availability of associates & fellows.
Work Area Staff/Assoc/Fell
Coordination 1.00
Hadronics 3.00
Geometry / Biasing 2.75
EM Physics 0.50
Testing and Soft Man 1.75
Total 9.00
Move of 0.25 FTEs to simulation project leadership pushed some geometry deliverables to 2005
LHCC Review , Nov 2004 Slide 12 Gabriele Cosmo, CERN/PH-SFT
Fluka Integration
Fluka is an official joint CERN-INFN project since January 2004 Fluka development is not an LCG activity
Participation involves Integration of Fluka as a simulation engine in the simulation
framework with FLUGG Physics validation
Working with the physics validation subproject – simple benchmarks, test beam (manpower issues !)
Activity is led by Alfredo Ferrari Fluka source code public at CERN by end of 2004
LHCC Review , Nov 2004 Slide 13 Gabriele Cosmo, CERN/PH-SFT
Fluka Integration
Current developments Physics
Heavy ions transport and interactions DPMJET-III interface done Electromagnetic Dissociation done Special effects in heavy ion Coulomb interactions in progress Development of QMD models in progress
Fragmentation Code structure and user interface (pre-condition for the full release) in progress
Integration of PEMF functionalities in the run time code Name-oriented advanced input interface General clean-up Publication of code documentation as CERN yellow report
Man power issues Physics developments: covered by A.Ferrari and non-CERN collaborators OK “Complex benchmarks” (test-beams): expertise support from FLUKA team, manpower
must come from LCG ? Code structure and user interface (release oriented) : CERN-AB manpower absorbed by
urgent LHC tasks. CERN-PH ending soon critical
Struggling to keep the December-Januarydeadline for the public β release of the full code
LHCC Review , Nov 2004 Slide 14 Gabriele Cosmo, CERN/PH-SFT
Physics Validation
Validation based mainly on Comparisons with LHC detector test beam data “Simple benchmarks”: thin targets, simple geometries
Coordinates a lot of work being done in the experiments, Geant4, Fluka Foster cooperation, coherence, completeness
Output of the project Certification that simulation packages are OK for LHC physics
Understanding strengths/weaknesses/uncertainties of Geant4, Fluka Contributions to systematic errors of measurements
Recommended optimized physics lists Simulation benchmark suite for acceptance and performance
monitoring Final report summarizing the work
LHCC Review , Nov 2004 Slide 15 Gabriele Cosmo, CERN/PH-SFT
Physics Validation – Status
Geant4 electromagnetic physics validated at percent level Simulation physics requirements revisited First round of hadronic physics validation has been completed, with good results
For the observables, in the case of the simple benchmarks (pixels, neutron double differential, pion absorption) there is a reasonable agreement between data and both Geant4 and Fluka
For the calorimeter test-beams, Geant4 describes well the pion energy resolution, σ/E, and the ratio e/
The shape of hadronic showers needs some improvement LCG notes: 1. F.Gianotti et al., CERN-LCG-APP-2004-02
2. A.Ribon, CERN-LCG-APP-2004-09
3. F.Gianotti et al., CERN-LCG-APP-2004-10
4. W.Pokorski, to be released very soon Monthly meetings presenting and coordinating experiment and project work Information, results gathering on web page
LHCC Review , Nov 2004 Slide 16 Gabriele Cosmo, CERN/PH-SFT
Physics Validation – Ongoing and Future Work
Validate precision of Geant4 electromagnetic physics at the permil level More detailed studies of hadronic shower profiles, both at the simulation and
experimental (test-beam data) level. Evaluate the possibility to study another simple benchmark, relevant to LHC,
to validate both Geant4 and Fluka. Man power could be a problem here!
Complete validation for Fluka in the calorimeter test-beam validations (as it has been done for Geant4)
The adoption of FLUGG and strong interaction with the Simulation Framework project is required here
Geant4 studies of background radiation in the LHC caverns in progress Will be soon compared with Fluka.
Man-power: People from the experiments are busy with the new test-beam data From LCG: M. Gallas, W. Pokorski, A. Ribon
all of them involved in other activities! First version of simulation test and benchmark suite delayed to end 2004 Physics validation document delayed to June 2005
LHCC Review , Nov 2004 Slide 17 Gabriele Cosmo, CERN/PH-SFT
Physics Validation Manpower
Witek Pokorski ~ 0.4 FTE simple benchmarks and generic framework (general infrastructure
supporting test beam physics validation) Alberto Ribon ~ 0.5 FTE
project leader, test beam calorimeters with Fluka, simple benchmarks Giuseppe Daquino (Geant4 team) ~ 0.75 FTE
radiation background simulation with Geant4 (biasing), background studies in the LHCb detector environment
Manuel Gallas Terreira ~ 0.75 FTE ATLAS combined test-beam simulation
Total ~ 2.4 FTEs ~ 1.5 FTEs currently shifted to experiments-specific validation activities ~ 0.9 FTEs dedicated to simple benchmarks, test beam calorimeters and
coordination !
LHCC Review , Nov 2004 Slide 18 Gabriele Cosmo, CERN/PH-SFT
Hadronic interactions in ATLAS pixel test-beam
A.Ribon LCG-APP-2004-09
LHCC Review , Nov 2004 Slide 19 Gabriele Cosmo, CERN/PH-SFT
Energy resolution of pions
beamtestEsimulationE
LHCC Review , Nov 2004 Slide 21 Gabriele Cosmo, CERN/PH-SFT
CMS longitudinal shower profile in HCAL for 100 GeV pions
LHCC Review , Nov 2004 Slide 22 Gabriele Cosmo, CERN/PH-SFT
Generator Services
Goal: guarantee the generator support for LHC WP1 - Generator services library (GENSER) WP2 - Tuning and validation of event generators WP3 - Common generator event files, event database (MCDB) WP4 - Event format, interfaces and particle services
Oversight of MC4LHC Project Leader: P.Bartalini (Florida). Most of the resources from LCG Russia.
Generator library – GENSER – progressing well First “production-quality” version 1.0.0 expected for December ATLAS uses GENSER in production, LHCb and CMS currently validating Addresses LHC experimentalists and theorists both at CERN and in external laboratories Supports many MC4LHC-mandated generators, including all first-priority ones
List as of mid-September - GENSER 0_2_0 release: HERWIG (P.Richardson), PYTHIA (T.Sjöstrand), HIJING (X.N. Wang), ISAJET (F.E. Paige), LHAPDF (M.Whalley), ALPGEN (M.Mangano), COMPHEP (A.Sherstnev), EVTGENLHC (P. Robbe), GLAUBER (V.Uzhinsky), FROZEN (PHOTOS, PDFLIB), 10 generators, different versions
In future, to come: CASCADE (H.Jung), DPMJET, MC@NLO, GRACE, MADGRAPH, NEXUS, PHOJET (Z.Was), SFM, TAUOLA, HERWIG++, PYTHIA 7, SHERPA (F.Krauss)
Internal MC4LHC review in March 2004 Definition of a release policy and roles for the GENSER librarian (A. Pfeiffer, PH/SFT) Involvement of A.Ribon (LCG) to help the project leader as ‘liaison’ person between MC
authors and experiments.
LHCC Review , Nov 2004 Slide 23 Gabriele Cosmo, CERN/PH-SFT
Generator Services - 2
Tuning and validation of event generators Advanced proposal for an event generator validation framework
Basic sanity check in standalone way in GENSER sub packages Physics validation through JetWeb (UK collaboration)
Validation of ALPGEN and HIJING in collaboration with groups in Perugia and Dubna
Common event file production / event database Event file database MCDB α-version deployed Core software (MySQL, POOL, CASTOR (RFIO), …) supported by LCG
Software Project Infrastructure Web Interface with dedicated web server: http://mcdb.cern.ch
α version deployed, being extended to support most common browsers Configuration and book-keeping tested at Fermilab and CMS Identified production centers (Santander, Oviedo)
Leveraging existing CERN production infrastructure Event formats and interfaces
HEPML as proposed meta-data format, based on XML for interfacing matrix element generators and showering/hadronization generators
HEPMC as interface between generators and MC simulators Support the new OO MCs (ThePEG, PYTHIA 7, HERWIG++, SHERPA)
LHCC Review , Nov 2004 Slide 24 Gabriele Cosmo, CERN/PH-SFT
Generator Services Oversight/Review
Review of the subproject conducted in March (M. Mangano chair and MC4LHC chair) with participation from experiment experts and many leading generator authors
Review report end of April with clear elements Project is delivering what the experiments need
GENSER in production in ATLAS, under validation in CMS and LHCb Manpower issues to be addressed
Stability in project leader: P.Bartalini (now University of Florida) Librarian positions: A.Pfeiffer LCG librarian for GENSER and defined
release policy Communication with the generator providers
A.Ribon as ‘liaison’ person between MC authors and experiments Primary role of Russian collaborators in the “assembly” process of
features to be included in sub-packages
LHCC Review , Nov 2004 Slide 25 Gabriele Cosmo, CERN/PH-SFT
Generator Services 2004 (and beyond) Milestones
Jan 2004 – Proposal for MCDB deployment in the LCG environment Feb 2004 – LHAPDF generator included in generator library Mar 2004 – Agreed format for event-level generator files Apr 2004 – COMPHEP, ALPGEN and EVTGEN in GENSER Jun 2004 – Proposal for generator event production environment Jul 2004 – Beta version of MCDB in production Jul 2004 – Proposal for an event generator validation framework Sep 2004 – Agreement on parton-level event generator file format Dec 2004 – Generator production framework final release
Plan extends through 2005-2006 to reach complete, production versions of GENSER, MCDB, validation framework, etc. (in blue those not yet verified)
Mar 2005 - First C++ Monte Carlo fully integrated in GENSER Jun 2005 - Generator level production framework "beta version 0_1_0" Jun 2005 - First test of ThePEG and Evtgenlhc integration in Herwig++ Sep 2005 - Production centre integrated in the grid-middleware Sep 2005 - Integration of GENSER in JetWeb Dec 2005 - Generator level production framework "release version 1_0_0" Mar 2006 - MCDB Integration, experiment specific APIs and management of
large files Jun 2006 - Generator level validation framework beta version
LHCC Review , Nov 2004 Slide 26 Gabriele Cosmo, CERN/PH-SFT
Generator Services – perspectives on required resources
Critical situation of resources for future developments in GENSER Particularly concerning the new MC generators
Little resources available for the validation activity Requiring MC experts !
Long-term resources for user-support required User-support expected to grow ! IT-expert for maintenance, MC-expert for development E.g. - FAQ for GENSER did not start for lack of resources …
See manpower tables for 2004 and estimation for 2005 in appendix
LHCC Review , Nov 2004 Slide 27 Gabriele Cosmo, CERN/PH-SFT
Simulation Project Milestones
2003/12: Geant4 release 6.0 2003/12: Simulation physics requirements revisited 2003/12: Simulation framework prototype supporting G4 and FLUKA via FLUGG 2003/12: Proposal for MCDB deployment in the LCG environment 2004/2: LHAPDF generator included in generator library 2004/2: First cycle of hadronic physics validation complete 2004/2: SPI-G4 collaborative infrastructure pilot 2004/3: Agreement on formats for event generator common samples 2004/3: Detector description (GDML) proposal to PEB 2004/03: Geant4 6.1 release - production improvements 2004/4: COMPHEP, ALPGEN and EVTGEN generators included in GENSER 2004/5: Review/prioritization of simple benchmarks for simulation physics validation 2004/6: Proposal for generator event production environment 2004/6: Geant4 6.2 release - resource usage refinements 2004/7: Beta version of MCDB in production in the LCG environment 2004/7: Proposal for an event generator validation framework 2004/9: Agreement on parton-level event generator file format 2004/9: Comparison of LHC calorimeters for EM shower development 2004/10: Geant4 geometry volume registration customization 2004/10:First consolidated G4 acceptance suite for LHC applications 2004/12: Generator production framework, final release 2004/12: Geant4 physics model prototype concluded 2004/12: Second iteration of hadronic physics validation complete 2004/12: Simulation test and benchmark suite available 2004/12: Geant4 7.0 release - physics models and geometry 2004/12: Geant4 validation in LHC production 2005/06: Final physics validation document complete
LHCC Review , Nov 2004 Slide 28 Gabriele Cosmo, CERN/PH-SFT
Simulation Project Major Milestones
2003/12: Simulation physics requirements revisited 2003/12: Simulation framework prototype supporting G4 and FLUKA via FLUGG 2004/2: First cycle of hadronic physics validation complete 2004/2: SPI-G4 collaborative infrastructure pilot 2004/3: Agreement on formats for event generator common samples 2004/5: Review/prioritization of simple benchmarks for simulation physics validation 2004/6: Geant4 6.2 release - resource usage refinements 2004/7: Beta version of MCDB in production in the LCG environment 2004/9: Agreement on parton-level event generator file format 2004/9: Comparison of LHC calorimeters for EM shower development 2004/10:First consolidated G4 acceptance suite for LHC applications 2004/12: Generator production framework, final release 2004/12: Second iteration of hadronic physics validation complete 2004/12: Simulation test and benchmark suite available 2004/12: Geant4 7.0 release - physics models and geometry 2004/12: Geant4 validation in LHC production 2005/06: Final physics validation document complete
LHCC Review , Nov 2004 Slide 29 Gabriele Cosmo, CERN/PH-SFT
Current simulation manpower
Simulation framework 0.50
Geant4 8.65
Infrastructure, performance, management (approx) 2.75
EM / Hadronic physics effort (approx) 3.55
Tracking, biasing, geometry (approx) 2.35
CERN staff (4.15), CERN fell./assoc. (4.25), LCG (0.25)
Physics validation 2.40
Validation specific to experiments 1.50
Generator services 2.35
mgmt. (Florida Univ.), documentation/release (LCG/CERN) 0.60
GENSER dev., Validation, MCDB (LCG Russia) 1.50
Production Framework (LCG Spain) 0.25
FLUKA integration 0.00
Management 0.25
Total 14.05
As of Oct 1
LHCC Review , Nov 2004 Slide 30 Gabriele Cosmo, CERN/PH-SFT
Concluding Remarks
Striking success of Geant4 in the LHC experiments ATLAS, CMS and LHCb now using it in full production
Crash-rate close to zero ! Strict collaboration with Geant4 team for support and new requirements
Very active program in physics validation delivering results and conclusions Shift of manpower to experiment-specific validation activities (ATLAS, LHCb) First cycle of hadronic physics validation completed New program of work for test-beam validation and simple benchmarks to be
defined, also according to the available manpower in the project Outstanding progress for generator services
First production release of GENSER in December Already used in production in ATLAS, under validation in CMS and LHCb Impressive collection of validated generator packages with common event DB
Manpower issues partially addressed Simulation framework program scoped to make maximal use of existing software and
meet the reality of minimal available manpower Prototype setup based on Flugg for physics validation Extension of GDML and implementation of interfaces for Geant4/Root to import
and export geometry descriptions Investigations and prototyping on Python-based interfaces
Fluka integration/validation feeling effects of slow progress due to low manpower (physics validation, Flugg framework)
Expected public source-code release of Fluka soon
LHCC Review , Nov 2004 Slide 33 Gabriele Cosmo, CERN/PH-SFT
ALICE – AliRoot Framework
TGeant3 Currently used in production
TFluka Implementation completed and interfaced to TGeo Testing ongoing
TGeant4 Implementation completed Interfacing to TGeo planned
User Code VMC
Virtual Geometrical
Modeller
G3 G3 transport
G4 transportG4FLUKA transport
FLUKA
Geometrical Modeller (TGeo)
Reconstruction
Visualisation
Using VMC (Virtual Monte-Carlo)
External Generators integrated into AliRoot HIJING for underlying event simulation PYTHIA: jets, heavy flavor
Plans for 2005 Validation of the Geometrical Modeller
(GM) with Geant3 and Fluka Extension of the interface to Geant4 Validation of the Geant4 interface Validation of new AliRoot simulation
with GM, including physics Phasing out Geant3.
LHCC Review , Nov 2004 Slide 34 Gabriele Cosmo, CERN/PH-SFT
ALICE – Physics Validation
Emphasis on simple (thin target) benchmark tests Thin target benchmark tests represent the only direct way of
physics validation Calorimeter tests lead in the best case to a multi-parameter tuning
of MC parameters, but not to a better understanding of the underlying physics
Benchmark tests started by ALICE and continued within the LCG simulation project
Test-beam simulation activities ongoing for ITS, TPC, HMPID Problem of manpower Support from LCG requested, but not obtained
LHCC Review , Nov 2004 Slide 35 Gabriele Cosmo, CERN/PH-SFT
ALICE - Status of Simulation ProductionPhysics Data Challenge ‘04
Test and validate the ALICE Offline computing model: Produce and analyse ~10% of the data sample collected in a
standard data-taking year Use the entire (complicated) system: AliEn, AliROOT, LCG,
Proof… Dual purpose: test of the software and physics analysis of the
produced data for the Alice PPR Structure:
Logically divided in three phases: Phase 1 - Production of underlying Pb+Pb events with different
centralities (impact parameters) + production of p+p events Phase 2 - Mixing of signal events with different physics content
into the underlying Pb+Pb events (underlying events are reused several times)
Phase 3 – Distributed analysis
LHCC Review , Nov 2004 Slide 37 Gabriele Cosmo, CERN/PH-SFT
ATLAS - Status
A Geant4-based simulation suite for the ATLAS experiment is in place (and available to developers) since mid-’03 Data Challenge phase-2 (summer 2004)
Geant4 -based, ~12M events (leap of faith) Tests of the ATLAS computing model, distributed production Running right now
Characteristics Based on home-grown simulation infrastructure (FADS) Interfaced to the ATLAS common framework (ATHENA) Persistency based on POOL Unified detector description scheme as in ATLAS (GeoModel)
Hand-coded geometries being phased out ~5 millions of positioned volumes (~300K volume types) All detectors described to a very high level of detail Detector configuration chosen at run time Detailed field map covering the whole detector
Primary numbers from NOVA/MySQL (now from Oracle) UI currently provided by Geant4 (moving to python) Several Physics Lists available at any time (QGSP_GN by default)
Very low tracking cuts for precise physics (20-30m in the calorimeters) About 400Mbytes at run time
~660secs for Ze+e-, ~770secs for SUSY events (PIV, 2.4Ghz) over the whole rapidity range ||6 Heavy ions trial successfully done (few full events generated in |eta|<6 or 3.2
LHCC Review , Nov 2004 Slide 38 Gabriele Cosmo, CERN/PH-SFT
Physics validation programme helped debugging the sub-detectors in an independent way
200 talks in a time span of 3 years Sub-detector integration took several months (2003)
Make sure there are no overlaps and check detector layout Move to new detector description scheme Implement missing bits &pieces (services, dead material etc.) Optimize performance
Running long tests since September 03 Continuous monitoring helps maintaining the program functional
Set up production environment in the meantime Currently running Geant4 6.2 for development work and CTB
simulation
ATLAS - Production setup
LHCC Review , Nov 2004 Slide 39 Gabriele Cosmo, CERN/PH-SFT
ATLAS - DC2 production
Slowed down by instability of the production tools GRID middleware?
Simulation part completed 12M events
Exceptional Geant4 performance and robustness Only two jobs crashed b/c of Geant4 problems !
log file examination pending … NorduGrid sample (3.5M events) completed with no job failure !
35K jobs ! 1M Ze+e- events without any problem !
Continuing now with further tests (Tier-0 production…) which are not relevant to Geant4
LHCC Review , Nov 2004 Slide 40 Gabriele Cosmo, CERN/PH-SFT
ATLAS - Future plans
Production for the ATLAS CTB (ongoing) Continuous production (starting in December) for the physics
community Physics Workshop in Rome, May ’05
Commissioning DC-3
ATLAS “initial” layout “GeoModel-ization” of the LAr calorimeters Implementation of missing bits (shielding, support structures…) Python General refurbishing
LHCC Review , Nov 2004 Slide 42 Gabriele Cosmo, CERN/PH-SFT
CMS - OSCAR
In CMS, OSCAR, the OO simulation program based on the Geant4 toolkit, has successfully replaced its Fortran/Geant3 predecessor. It has been validated and adopted by all CMS detector and physics groups. It has proven robust and performant, easily extensible and configurable
Complete CMS geometry: 1M geometrical volumes 35M pp interaction events produced Time ~ 200 sec/event at 2.8 GHz CPU (High ET QCD events) First 100 PbPb heavy ion events
CMS has now entered sustained-mode production: 10M physics events/month through the full chain (simulation, digitization, …, DSTs)
OSCAR 3.6.0 released now with G4.6.2 p1 new validation phase (new field map, new forward detectors, new G4 version, many
improvements…) Deploy for mass production next month Continuing validation of G4 physics (EM+HAD) and performance optimization
important. CMS participates in this common effort
LHCC Review , Nov 2004 Slide 43 Gabriele Cosmo, CERN/PH-SFT
OSCAR/G4: Performance
CPU time of OSCAR 2.4.5 (with Geant4 5.2 p2) is 2xGEANT3 time, but much more sophisticated cut/region scheme more conservative cuts than for CMSIM more detailed physics in G4 improvements implemented by G4 team, and by CMS through more
optimized access to/use of the (new) magnetic field. we have now a 20-30% better performance of OSCAR 3.6.0 (with G4.6.2
p1) compared to the version 2.4.5. So now we are at 1.5 x GEANT3; effort is continuing
Memory usage in OSCAR 2.4.5: 220 MB OSCAR vs 100 MB GEANT3 simulation.
further optimization led to ~110 Mb/event for pp (>500 Mb/event for HI) Crashes occurred with 2.4.5: about 1/10000 for pp events. Mostly hadronic
physics (baryon decays, -nuclear intertactions) latest stress test (800K single particles, 300K full QCD events) showed no
single crash ! Many thanks to G4 for help!
LHCC Review , Nov 2004 Slide 44 Gabriele Cosmo, CERN/PH-SFT
CMS – LCG projects
Other LCG projects GENSER being validated, plan to deploy early 2005 Use FLUKA via FLUGG if PRS groups in CMS
require it Validation: participate with new 2004 HCAL and
ECAL testbeam data (beam energies down to 2 GeV, longitudinal readout)
Future Production of additional O(100K) events with OSCAR
for physics TDR
LHCC Review , Nov 2004 Slide 45 Gabriele Cosmo, CERN/PH-SFT
Validation of the Physics in OSCAR
CERN-LCG-2004-10
Validation of G4 physics in the context of the LCG study group So far: Comparisons of hadronic test beam data with models in G4Also: Comparison of EM physics with test beam data
Studies of energy resolutions, e/ ratios, and shower profiles
GenerallyQGSP modeladequate
LHCC Review , Nov 2004 Slide 46 Gabriele Cosmo, CERN/PH-SFT
Physics Events with OSCAR
View of 180 Higgs ZZ event simulated in CMS Tracker detector
SUSY events (LM4 point: leptons, missing ET)
Samples of “standard sets” of events nowautomatically produced for each new release
LHCC Review , Nov 2004 Slide 47 Gabriele Cosmo, CERN/PH-SFT
Ultimate test: Heavy-Ion Collisions CMSIM: chop event in slices of 100 tracks, run them separately
Needed due to limitations in CMSIM OSCAR/Geant4 can run full events.
Timing is good/Memory > 500 Mbyte (2GB memory machines used) Have now run 100 events without problems
Program CPU (2.8GHz) (min)
CMSIM 230OSCAR 2_4_5
320
OSCAR 3_4_0
180
~ Timing for the first event with55K generator tracks
The first CMS PbPb event with OSCAR/G4
LHCC Review , Nov 2004 Slide 49 Gabriele Cosmo, CERN/PH-SFT
LHCb - Simulation status
Gauss, the “new” Gaudi/Geant4 based simulation application has been put in production this year main simulation engine has replaced Geant3 based simulation for overall simulation to mimic what will
happen in the spectrometer and understand experimental conditions and performance
integrates two independent phases:1. generation of proton-proton collisions and decays of b hadrons
2. tracking of particles in the detector and interactions with the material
production of “hits" when particles cross sensitive detectors makes use of simulation external engines via dedicated interfaces and services
Pythia, EvtGen, HepMC, Geant4 based on LHCb Gaudi framework, EventModel and Detector Description
Digitization performed by Boole a different application Dedicated background studies also performed with FLUKA
LHCC Review , Nov 2004 Slide 50 Gabriele Cosmo, CERN/PH-SFT
LHCb - Gauss status
Gauss is fully operational complete
all detectors simulated all information needed in later processing provided
stable low crash rate, reasonable CPU time good collaboration with Geant4 team to achieve this ( various iteration before
frozen version for DC04 ) validated as replacement of Geant3 simulation with detailed comparisons under continuous validation with test beam data to tune physics settings
work in different sub-detectors at different paces based on their needs and data (RICH, ECAL,…)
collaboration with LCG physics validation project also to use Geant4 for radiation studies
LHCC Review , Nov 2004 Slide 51 Gabriele Cosmo, CERN/PH-SFT
LHCb - Gauss in production (May – August)
LCG inaction
1.8 106/day
LCG paused
Phase 1 Completed
3-5 106/day
LCG restarted
186 M Produced Events
Still producing data
Data produced in ~ 60 different sites
In each job 3 or 4 sets of 500 events produced with Gauss
Geant4 version 6.1
LHCC Review , Nov 2004 Slide 52 Gabriele Cosmo, CERN/PH-SFT
LHCb - Simulation developments & plans - 1
Data produced with Gauss in DC04 will be intensively scrutinized in the coming months by many physicists
allow to understand, improve the simulation, fix bugs, identify new needs Ongoing developments
Validating GENSER as provider of generator libraries need to be “stable” for use in production collaborating for LHC version of EvtGen
Adopting and validating new versions of Geant4 as they are available provide feed back and new requirements to Geant4 try out new relevant features
Physics validation (tuning) with test beam analysis RICH, ECAL test beams just completed, analysis in progress
LHCC Review , Nov 2004 Slide 53 Gabriele Cosmo, CERN/PH-SFT
LHCb - Simulation developments & plans - 2
Future developments ( in random order ) Introduce more realism and details in Gauss
understand better both the simulation and test beam data physics tuning (… or validation) Further investigation of use of Geant4 for radiation studies Introduce accelerator contributions to background (halo, beam gas, etc.)
Investigate alternative, new paths to those adopted currently in Gauss delta rays production production/tracking cuts per region investigation of tracking in magnetic field (parameters, regions)
Investigate use of other generators for proton-proton collisions Follow LCG simulation projects developments
LHCC Review , Nov 2004 Slide 55 Gabriele Cosmo, CERN/PH-SFT
Geant4 in LCG/SI, and collaborations
The Geant4 LCG/SI sub-project and the Geant4 Collaboration LCG/SI/G4 responsible for CERN/LHC participation in Geant4
Maintaining the focus of CERN/LHC effort on LHC priorities Leading role in management, development and infrastructure within the
Geant4 Collaboration Work plan integrated with overall Geant4 plan
Physics: hadronic and electromagnetic Geometry and tracking in field Infrastructure, management, coordination
Collaborating with sub-projects & other LCG project, with experiments teams on validation, robustness and infrastructure
Collaboration with Physics Validation, experiment detector groups Some improvements, updates are direct consequence of this feedback
Collaborated with experiment simulation teams, e.g. on robustness Substantial decrease in job crash rate in past year
Work with the framework team on geometry exchange Worked on shared infrastructure (testing, portal) with SPI
LHCC Review , Nov 2004 Slide 56 Gabriele Cosmo, CERN/PH-SFT
Geant4-based Simulations in ATLAS, CMS, LHCb
Three LHC experiments (ATLAS, CMS, LHCb) are now using Geant4 successfully in production
ATLAS G4 simulation is now the ‘standard’ in ATLAS DC2 (summer 2004) produced 12M events
OSCAR (G4) has successfully replaced CMSIM (G3) in CMS 35 M pp interaction events, and first 100 Pb-Pb events
GAUSS (G4) has replaced G3 based simulation for 2004 production
Over 200 M events simulated Reliable in production, with low crash rate (and decreasing with
each release) Rate decreasing from 1/10K events (5.2, CMS) to 1 per Million
events (6.1, LHCb) G4 team addressed issues found in test productions
LHCC Review , Nov 2004 Slide 57 Gabriele Cosmo, CERN/PH-SFT
Geant4: sample details of highlights
Establishment of ‘statistical testing’ suite Automating comparisons of physics quantities
Simple setups for ‘regression testing’ Simplified, typical HEP detectors without digitization Complementing INFN and SLAC efforts (comparing to NIST
data) and full LHC ‘test-beam’ comparisons Identifying problem conditions
In hadronics by recording initial reaction conditions and printing them out in case of ‘soft’ error or program crash problems are reproduced easily, identified and fixed quickly
In geometry by providing a new ‘check’ mode Giving users information on difficulties with their setup
LHCC Review , Nov 2004 Slide 58 Gabriele Cosmo, CERN/PH-SFT
Geant4: future goals (more detail)
Additional geometry/biasing goals: Enable use of dual geometries for radiation studies Improve detection of problems in ‘user’ geometry models
Better identifying issues in large scale productions Improve field tracking, by taking account (inside a ‘step’) of effect of energy loss on
momentumAdditional potential EM goals: Enable the refining of multiple scattering for pions and electrons Improve modeling of transition radiation detectors
and provide specific customization for ATLAS and ALICE XTR detector setups Enable the use of shower parameterization in sampling calorimetersAdditional potential hadronic goals: Establish a 'data service' for radiation studies Establish the use of binary cascade in conjunction with QGS model Bring CHIPS ‘string’ prototype to fruition Validate ion reactions for use in HEPContribute and enable the Geant4 physics teams to: Establish service for physics lists in emerging/upcoming LHC use-cases Establish physics for exotics (ex.: R-hadrons) in collaboration with experiments Provide additional modeling options for most-sensitive use cases
LHCC Review , Nov 2004 Slide 59 Gabriele Cosmo, CERN/PH-SFT
In-flight Pion Absorption
pi+/-
W.Pokorski - LCGAPP note almost ready
LHCC Review , Nov 2004 Slide 60 Gabriele Cosmo, CERN/PH-SFT
LHC hadronic calorimeter test-beams
extended barrelmodule
extended barrelmodule
η=0.25η=0.65
Crystal 25
F. Gianotti et. al LCG-APP-2004-10
CMS HCAL & ECAL test beam setup
ATLAS HEC test beam
ATLAS Tilecal test beam setup
LHCC Review , Nov 2004 Slide 61 Gabriele Cosmo, CERN/PH-SFT
Generator Services – manpower 2004
Coordination: 0.25 (0.50) WP1. GENSER – 0.70 (1.00)
Development: 0.50 (0.50) LCG Russia Maintenance: 0.10 (0.25) LCG Russia User Support: 0.10 (0.25) LCG Russia
WP2. ThePEG – 0.10 (0.25) Development: 0.10 (0.25) * Alberto * (documentation) Maintenance: 0.00 (0.00) Not yet an issue
WP3. MCDB & Simple Production Framework – 1.25 (1.25) Development: 0.75 (0.75) LCG Russia Maintenance: 0.00 (0.00) Not yet an issue User Support: 0.00 (0.00) Not yet an issue Framework Development: 0.50 (0.50) LCG Spain / CMS Framework Maintenance: 0.00 (0.00) Not yet an issue Framework User Support: 0.00 (0.00) Not yet an issue Production 0.00 (0.00) Spanish CENTRE (to be started 2005)
WP4. Validation – 0.30 (1.00) Validation (Standalone) 0.30 (0.50) LCG Russia Validation (Framework) 0.00 (0.50) Collab with JetWeb (NOT STARTED)
LHCC Review , Nov 2004 Slide 62 Gabriele Cosmo, CERN/PH-SFT
Generator Services – manpower 2005
Coordination: 0.25 (0.50) WP1. GENSER – 1.00 (1.50)
Development: 0.50 (0.50) LCG Russia Maintenance: 0.25 (0.50) * Andreas * User Support: 0.25 (0.50) LCG Russia
WP2. ThePEG – 0.25 (0.25) Development: 0.00 (0.00) Frozen Maintenance: 0.25 (0.25) * Alberto *
WP3. MCDB & Simple Production Framework – 1.75 (2.25) Development: 0.50 (0.50) LCG Russia Maintenance: 0.25 (0.25) LCG Russia User Support: 0.25 (0.25) LCG Russia Framework Development: 0.50 (0.50) LCG Spain Framework Maintenance: 0.25 (0.25) LCG Spain Framework User Support: 0.00 (0.25) Not sure LCG Spain can guarantee Production: 0.00 (0.25) LCG Spain (first tests)
WP4. Validation – 0.25 (1.00) Standalone: 0.25 (0.50) LCG Russia Framework: 0.00 (0.50) Cannot Start if no resources...
LHCC Review , Nov 2004 Slide 64 Gabriele Cosmo, CERN/PH-SFT
Example TFluka Testing:RICH 5 GeV Pions
Geant3 FLUKA
LHCC Review , Nov 2004 Slide 65 Gabriele Cosmo, CERN/PH-SFT
PDC’04 Phase I
Centrality name Impact parameter value [fm] Produced events
Cent1 0 - 5 20K
Per1 5 - 8.6 “
Per2 8.6 - 11.2 “
Per3 11.2 - 13.2 “
Per4 13.2 - 15 “
Per5 > 15 “
LHCC Review , Nov 2004 Slide 67 Gabriele Cosmo, CERN/PH-SFT
ALICE Physics Data Challenges
Period(milestone)
Fraction of the final capacity (%)
Physics Objective
06/01-12/01 1%pp studies, reconstruction of TPC and ITS
06/02-12/02 5%
• First test of the complete chain from simulation to reconstruction for the PPR
• Simple analysis tools• Digits in ROOT format
01/04-06/04 10%
• Complete chain used for trigger studies• Prototype of the analysis tools• Comparison with parameterised MonteCarlo• Simulated raw data
05/05-07/05 TBD
• Refinement of jet studies• Test of new infrastructure and MW• TBD
01/06-06/06 20%
• Test of the final system for reconstruction and analysis
LHCC Review , Nov 2004 Slide 69 Gabriele Cosmo, CERN/PH-SFT
View of the CMS detector
Sliced view of CMS barrel detectors
OSCAR
Complete CMS detector geometry includedMore than 1M geometrical volumes
muon detectors
LHCC Review , Nov 2004 Slide 71 Gabriele Cosmo, CERN/PH-SFT
Crash analysis
A production job is made of several steps: 3 (signal + 2 minbias) Gauss (detector simulation) – 500 events
or 4 (b-incl + 3 minbias) Gauss – 500 and 3*300 events
Two periods analyzed: 62635 jobs run between 5th May and 28th of June
1111 jobs crashed in one of the Gauss runs for any reasons 29 stopped in the generator step 667 stopped in the Geant4 step which includes GiGa interface
97718 jobs run between 16th August and 19th October 529 jobs crashed in one of the Gauss runs for any reasons 85 stopped in the generator step 278 stopped in the Geant4 step which includes GiGa interface
Bug fixes and protections introduced between the 2 periods for ex. against some looping particles
LHCC Review , Nov 2004 Slide 72 Gabriele Cosmo, CERN/PH-SFT
Gauss in production - DC04
Gauss used in LHCb data challenge (DC04) started 3rd of May 2004 in production environment for the first time (after tests) check its robustness Pythia 6.205 for pp-collision generation EvtGen v5r0 ( LHCb modification from – 00 – 11 – 07 ) for B
decays
Geant4 6.1 for detector simulation three versions of Gauss - fix bugs identified in production
in conversion of MCtruth particle getting stuck during tracking
LHCC Review , Nov 2004 Slide 73 Gabriele Cosmo, CERN/PH-SFT
Debugging Gauss in production
More than 50% of the Gauss crashes are independent of Geant4 For the ~ 50% occuring in the Geant4 step
Detailed information available when a problem occurs for foreseen reason is very useful
As it is done in Hadronic processes Detailed printout for normal situation
very important when developing or adopting a new Geant4 version should be under the control of the user to not clutter log files during
production