GLAST Geant4 Simulation

Transcription

1 GLAST Geant4 Simulation F.Longo D. Favretto R.Giannitrapani 1

2 Introduction Simulation effort GammaRayTel advanced example in the Geant4 3.0 release XML - Geant4 visitor Hit class 2

3 Simulation Effort Design and optimise the detector Develop and test the reconstruction and analysis programs Interpret the experimental data 3

4 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. 4

5 GammaRayTel example Geometry Hits Classes Physics Digitizer Module Trigger Evaluator Astrophysics Persistency Analysis tools 5

6 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 6

7 VRML visualization Simple example of VRML file 7

8 Hits & SD classes 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) 8

9 Particle Generation Simple Generator with Messenger Isotropic or point source Spectral Options Integration with GSPM 9

10 Analysis Tools 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 10

11 Analysis Tools 11

12 Projects Digitizer Module FITS persistency ESA space modules 12

13 Digits ReadOut Geometry utilization for the Tracker Digitizer module for TKR and CAL Example of Trigger function of EventAction class Example of Digitization inside G4 13

14 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 14

15 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 15

16 XML client 16

17 XML client 17

18 XML client 18

19 Hit Class Sensitive Volumes (from XML) Pre and Post Step Point Step length Energy deposition along the step Volume identifier (from XML) 19

20 Conclusions Ready for Validation Gaudi Integration Event Generator Interface 20