GLAST Geant4 Simulation

GLAST Italian Software
Roma, 4 maggio 2001
GLAST Geant4 Simulation
F.Longo
D. Favretto
R.Giannitrapani
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GLAST Italian Software
Roma, 4 maggio 2001
Introduction
• Simulation effort
• GammaRayTel advanced example in the
Geant4 3.0 release
• XML - Geant4 visitor
• Hit class
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GLAST Italian Software
Roma, 4 maggio 2001
Simulation Effort
• Design and optimise the detector
• Develop and test the reconstruction and analysis programs
• Interpret the experimental data
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GLAST Italian Software
Roma, 4 maggio 2001
Why Geant4?
• Toolkit for the simulation of the passage of
particles through matter. Various application areas
• Complete set of tools for all the domains of
detector simulation
• Set of Physics Processes across a wide energy
range
• Advanced Software Engineering techniques and
Object Oriented technology
• Transparency of the physics implementation with
the possibility of validating the physics results.
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GLAST Italian Software
Roma, 4 maggio 2001
GammaRayTel example
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Geometry
Hits Classes
Physics
Digitizer Module
Trigger Evaluator
Astrophysics Persistency
Analysis tools
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GLAST Italian Software
Roma, 4 maggio 2001
Present Situation
• Single “GLAST ”Tower
• Silicon Tracker, Plastic Scintillator Anticoincidence, CsI
Calorimeter
• Standard Electromagnetic Processes
• Hits Persistency (ASCII format)
• Hits Analysis on-line with AIDA-Lizard
• Setup Visualization with OpenGL, PostScript and VRML
http://www.ge.infn.it/geant4/lowE/examples/gammaray_telescope/index.html
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GLAST Italian Software
Roma, 4 maggio 2001
VRML visualization
• Simple example of VRML file
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GLAST Italian Software
Roma, 4 maggio 2001
Hits & SD classes
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Tracker, ACD and Calorimeter volumes as sensitive detectors
ACD information (side and energy release)
CAL information (plane, bar, position, energy release)
TKR information (plane, strip, position, energy release)
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GLAST Italian Software
Roma, 4 maggio 2001
Particle Generation
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Simple Generator with Messenger
Isotropic or point source
Spectral Options
Integration with GSPM
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GLAST Italian Software
Roma, 4 maggio 2001
Analysis Tools
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Released version with Lizard using AIDA
1d and 2d histograms
More than one histogram (with some difficulties)
Single or multiple views
Run-based or event-based
Messenger to choose modality
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GLAST Italian Software
Roma, 4 maggio 2001
Analysis Tools
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GLAST Italian Software
Roma, 4 maggio 2001
Projects
• Digitizer Module
• FITS persistency
• ESA space modules
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GLAST Italian Software
Roma, 4 maggio 2001
Digits
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ReadOut Geometry utilization for the Tracker
Digitizer module for TKR and CAL
Example of Trigger function of EventAction class
Example of “Digitization” inside G4
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GLAST Italian Software
Roma, 4 maggio 2001
FITS persistency
• Astrophysical Standard Type for DATA format
• Great Utility for real users (possibility to use standard external
analysis tools)
• Link with NASA FITSIO libraries
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GLAST Italian Software
Roma, 4 maggio 2001
XML client
• XML as the description format of the geometry
• G4GDD XML visitor inside DetectorConstruction class
• Logical Volumes, Physical positioning and volume hierarchy
represented
• With the use of a GEANT4 messenger it is possible to change
runtime both the XML file that contains the geometric
representation and the mother volume to simulate
– This permits to simulate, without any need to exit from the
simulation, any part of the detector independently
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GLAST Italian Software
Roma, 4 maggio 2001
XML client
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GLAST Italian Software
Roma, 4 maggio 2001
XML client
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GLAST Italian Software
Roma, 4 maggio 2001
XML client
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GLAST Italian Software
Roma, 4 maggio 2001
Hit Class
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Sensitive Volumes (from XML)
Pre and Post Step Point
Step length
Energy deposition along the step
Volume identifier (from XML)
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GLAST Italian Software
Roma, 4 maggio 2001
Conclusions
• Ready for Validation
• Gaudi Integration
• Event Generator Interface
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