Transcript GAUDI summary

LHCC Comprehensive Review 2006
Simulation Project Status
Gabriele Cosmo, PH/SFT
Simulation sub-projects
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Witold
Pokorski
Simulation framework
– Interface to multiple simulation engines (Geant4, Fluka) and geometry
models exchange (GDML), MC truth handling, Python interfaces
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Geant4 team participating
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Fluka team participating
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Garfield team participating
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Simulation physics validation
John
– Aligned with and responding to needs from LHC experiments, physics
Apostolakis
validation, simulation framework
Alfredo
Ferrari
Rob
Veenhof
Alberto
Ribon
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Witold
Pokorski
as of 15-Sep-06
– Framework integration, physics validation
– Garfield package integration and support in LCG - SPI
– Assess adequacy of simulation and physics environment for LHC and
provide the feedback to drive needed improvements
Generator services
– Generator libraries; validation/test suite; development when needed
(HepMC, etc.); common event files
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Project Organization
Geant4
Project
Experiment
Validation
Fluka
Project
MC4LHC
Simulation Project Leader
Subprojects
Framework
Work packages
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Geant4
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Fluka
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Garfield
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Physics
Validation
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Generator
Services
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Recent developments …
For details, see presentations at recent AA Internal Review:
http://agenda.cern.ch/fullAgenda.php?ida=a063165
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Geant4 - 8.0 (January release), developments
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New capabilities
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EM (‘standard’) : new MSC model implementation
New design for particle definitions, no longer ‘static’
Revised fast-parameterisation: usage of ‘regions’
Geometry overlap check at construction
Improvements and fixes
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to existing hadronic physics modeling & models
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Strong interaction and collaboration with Physics Validation project
in physics process implementations
extending functionality that existed
in good part result of user feedback and requirements
Migrations, updates
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Support for CLHEP 2.0.X series
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Keeping compatibility with 1.9.X series
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Geant4 - 8.1 (June release), developments
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Adoption of a new Geant4 Software License (and CA)
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Based on EGEE model: http://cern.ch/geant4/license/
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Updated particle definitions to match PDG-2005
New ‘material scanner’ utility
New ‘tessellated’ solids for interface with CAD systems
ß-release of very low-energy DNA processes in water
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Simulation of back-scattering improved
Improved stability of EM energy deposition, resolution
New capabilities
Numerous improvements in EM “standard” physics
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From revision of electron transport (Multiple Scattering)
Enables better accuracy at higher cuts - with less CPU
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Visible energy in sampling calorimeters less sensitive to production threshold
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New combined elastic-scattering models
Extended use of Binary and Bertini cascade models
Strong interaction and collaboration with Physics Validation project
Fixes in hadronic physics and reviewed physics-lists
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Geant4 - Robustness, testing
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Low rate of problems in production
– Was <~ 10-4 per LHC event with Geant4 release 5.x
– CMS reports 10-6 per event (G4-related) with Geant4 release 6.2
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New, large-scale, regressions testing
– Finds rare problems
– Used LCG/EGEE Grid
» Need and got > 150 CPU-weeks in 10 days
» Geant4 VO
 thanks to LCG team, CERN, Imperial C., Nikhef, CIEMAT
– Identifies physics revisions, finds new software issues
» For details, see A. Ribon’s talks at CHEP 2006, AA meeting
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Fluka - Major steps since mid 2005
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May 2005 : definition and approval of the FLUKA license
July 2005 : release of FLUKA 2005.6
– release of the FLUKA source code for INFN and CERN researchers
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October 2005 : Publication of the FLUKA description and
user guide as a CERN yellow report ( CERN-2005-010)
September 2006 : Release of FLUKA 2006.3
– release of the FLUKA source code to all scientific institutions
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Fluka - New Release: 2006.3
Major new features:
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(see release notes for details)
Input by names
Generation of primary ionisation events (request by ALICE)
New high-energy hadronic generator (available as option, will
become the default)
Improvements in the evaporation/fission models
First implementation of photon-muon pair production (mupair).
An initial implementation of the BME model for low energy
nucleus-nucleus interactions (available on request)
Activity concentration 2D/3D binnings (was only by region)
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Garfield - Developments
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Completion of the interface with QuickField
Reproducibility of random number sequences ensured;
Heed random number generator replaced to ensure
independence of long runs
Development of BEM (Boundary Element Methods) as an
alternative to field calculations using analytic methods and
finite element methods (FEM)
Use of BOINC for generation of transport tables for wide
selection of gases and wide range of magnetic field
configurations
– Usage of the GRID envisaged
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Porting on MacOS X
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Physics Validation
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Background radiation studies
– Goal: comparison of Fluka and Geant4 predictions
» Geant4 now offering a precise treatment of low
energy neutrons with some Physics Lists like
QGSP_BERT_HP
– Radiation studies in LHCb, CMS
– TARC benchmark test
» new benchmark for neutrons. Validates spallation
neutron production for GeV protons on pure lead, and
neutron transportation down to thermal energies
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Simple benchmarks
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Test beam setups
LHCb cavern
– inclusive π± production in π±,K+,p,p interactions on Mg,
Ag, Au, at 100 and 320 (π-) GeV/c – results ready!
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ATLAS EM barrel test beam 2002
CMS HCAL test beam 2004
ATLAS HEC test beam (Geant4 release validation)
ATLAS barrel combined test beam 2004
ATLAS TileCal test beam 2002
» First comparison with Fluka using GDML and
simulation framework
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TARC neutron benchmark
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Physics Validation -2
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Investigations in various directions are undergoing in strict
collaboration with Geant4 experts to understand and improve
hadronic shower shapes in the simulation
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Cross-sections (elastic and inelastic)
Model of the hadronic elastic scattering
Neutron production
Production (multiplicities), rapidity and spectra in hadron-nucleus collisions
Diffraction
Test bench prototype for ATLAS test beam 2002 LAr data
– Correct the data, as it is done for cross-sections measurements
– Allows Geant4 and Fluka developers to use directly the calorimeter testbeam data for validation purposes
Relation between simulation developers and experiments has
improved, and it is now very good!
Progress has been slower than expected
– Complexity of the setups
– Detailed description of instrumental effects
– Other commitments of people in the experiments …
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Generator Services - 1
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New Project leader: Witold Pokorski (PH/SFT) replacing P.Bartalini
GENSER
– New release last summer: 1.4.0
» Quarterly official releases (2nd digit incremented)
» ~3 weekly pre-releases before official releases (access to beta-testers)
» Bug fix releases (3rd digit incremented)
 Further special releases arranged under request
– New requests from LHC experiments (new generators, new versions of existing
generators, etc.)
» Collected in LCG Generator monthly meetings
– Modular packaging (since release 1.2.0)
– First release of Herwig++ in hadron colliders expected soon
– Migration from g77 to g95 and gfortran almost complete
– Widely used by three LHC experiments: satisfaction expressed
– Some critics expressed by MC authors in recent MC4LHC workshop in July
» Procedural mistakes in releasing and fixing bugs
» Packaging issues for some MC generators
» More testing needed for core generators
» Control of feedback and support requests from experiments
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Generator Services - 2
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Pythia 8
– T.Sjostrand working full time at CERN PH/SFT as research associate
– A fresh start, stand-alone C++, with 3 year road-map, Sep 2004 - Sep 2007
– Latest development version included in GENSER 1.4.0 – User’s feedback is
welcome!
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MCDB (MC event Data Base)
– Ready to use ! - http://mcdb.cern.ch
– Features: Web interface; database; search engine; CASTOR as native
storage; Grid compatible. Event files in HepML as unified XML format
– CMS migrating to the new service. Little interest for now from ATLAS
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Generators framework
– General interface to any generator provided by GENSER. Production &
Validation
– Based on: GENSER, HepMC, Root/Pool
– Developed and maintained in CMS; CMS production based on it
– Production framework is ready, Validation framework is in progress
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Simulation Framework - 1
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GDML (Geometry Description Markup Language)
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Extended to support all solids / constructs of Geant4
Added support for optical surfaces and material properties
Root binding: reader and writer integrated in Root
Geant4 binding:
» Support for modular GDML geometries
» Included converter CAD(STEP) to GDML
ST - Viewer
STEP files
An interactive tool for viewing
3D CAD information
ST – Viewer uses an internal file format
(.geom & .tree) to store geometry info
GDML Output File
STEPGDML
Equivalent to the original STEP file
Contains only tessellated solids
Library functions created to
convert STEP into GDML files
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Simulation Framework - 2
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FLUGG
– Extended detector construction to allow loading of GDML geometry
files
– Implemented manager of hits to mimic Geant4 behavior for the
“sensitive detectors”
– Added Root I/O persistency for hits
– Exercised with ATLAS TileCal test beam 2002 setup
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Python interfaces
– Reflex/PyROOT, Python binding for Geant4
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Geometry object persistency
– Extensions to Geant4 and Root to allow Root I/O binary persistency
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MC truth handling
– Implemented example 'MCTruthManager‘
– Using HepMC as the event record format
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Simulation Project major Milestones : 2005-2007
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2007/09:
VD502
VD508
VD512
SF515
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G4518
G4519
VD522
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GS527
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G4531
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GF540
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GS602
G4606
SF608
VD617
G4618
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Review/prioritization os simple benchmarks for physics validation
First results of background radiation studies in Geant4
New validation results on longitudinal shower shapes in Geant4
GDML schema extension to support divisions and reflections
Feasibility study of Pool/Root-based geometry persistency in Geant4
Python implementation of GDML writers for Geant4 and Root
Geant4 7.1 public release
Tutorial on Geant4 at CERN and move of Geant4 code repository to IT service
3rd simple benchmark completed
Validation of Fluka against ATLAS TileCal test-beam
Procedure for light GENSER releases
Flugg application to ATLAS TileCal test-beam simulation
Improved Geant4 regression suite for release validation and testing infrastructure
First results of ATLAS combined and 2004 test-beams data comparisons
Generator level production framework: production quality release
Evaluation of possible migration of HepMC to LCG
Introduction of modularization of GDML files
Proposal for universal handling of Monte Carlo truth
Interface in Garfield with new version of Magboltz
Interface in Garfield with new version of Heed
Geant4 8.0 public release
Introduction of MCDB GRID certificates and management of large files
Developments for Geant4 8.1 public release
Refinements to GDML schema to support user extensions of elements
Investigation of corrections to test-beam data for validation of stand-alone simulation engines
Report on the main physics effects responsible for hadronic shower development in Geant4
Application of corrections to test-beam data to the LHC calorimeter test-beam simulations
Generator level validation framework production version
Pythia 8 production release
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Current LCG simulation manpower
Simulation framework
1.80
Geant4
7.20
Infrastructure, performance, management (approx)
2.05
EM / Hadronic physics effort (approx)
3.90
Tracking, biasing, geometry (approx)
1.25
As of Sep 20
(1.40)
CERN staff (3.80), CERN fellows/associates (3.40)
Physics validation
2.30
Validation specific to experiments
1.50
Generator services
3.30
management, documentation/release (LCG CERN, Florida Univ.)
1.20
GENSER dev., Validation, MCDB (LCG Russia, Italy)
1.85
Production Framework (LCG Spain)
0.25
Fluka
0.00
Garfield
1.00
Management
0.25
Total
(3.50)
(0.20)
15.85
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