Geant4 application to X and Geant4 application to X and Gamma-ray TelescopesGamma-ray Telescopes

B.Ferrero Merlino1, D.Favretto2,

R. Giannitrapani2, F.Longo2, R.Nartallo3, P.Nieminen3, A.Pfeiffer1,

M.G.Pia2, G.Santin2

(1) CERN (2) INFN (3) ESA/ESTEC

OutlineOutline

Geant4 and space applications for X and Gamma Astrophysics

XRayTel and GammaRayTel examples– Geometry and Physics

– Visualisation

– Histogramming

– User Interface

AGILE & GLAST, real experiments– XML detector description

X and Gamma AstrophysicsX and Gamma Astrophysics

Gamma Ray Bursts: a puzzle being solved (since 1997)

Gamma-ray BurstsGamma-ray Bursts

(Credit NASA) (Credit BeppoSAX team) (Credit NASA/CNR/L.Piro et al.)

Geant4 and Space ApplicationsGeant4 and Space Applications

Source detection Different energy bands Several mechanisms Different detectors

Design and optimisation

of satellites

Geant4 and Space ApplicationsGeant4 and Space Applications

Background Simulation Different sources (radioactive

decay, cosmic origin,

detector noise, …)

XRayTel and GammaRayTel XRayTel and GammaRayTel examplesexamples

Advanced examples in the Geant4 toolkit (since release 3.0)

Properties– Advanced features of Geant4 toolkit

– Features of the Low Energy Electromagnetic processes in Geant4

– Reliability of Geant4 in a space environment application

Geometry and Physics Geometry and Physics for an X-ray Telescopefor an X-ray Telescope

Mirrors, Focal plane detectorsCosmic Ray generation & Focusing

Coded mask imagingPhotoelectric effect

Credit: NASA

Credit: ESA

Geometry and Physics Geometry and Physics for a generic Gamma Telescopefor a generic Gamma Telescope

Tracker, Calorimeter, Anticoincidence

Gamma ConversionElectron TrackingMultiple ScatteringDelta-ray productionCharged particle tracking

Detectors geometryDetectors geometry

Ni Conical mirrors (7.5 m)Gold coatingSilicon Detectors (50 m)

Lead converterSi detectors (400 m)CsI calorimeterPlastic anticoincidence

VisualizationVisualization

Lot’s of graphical drivers– OpenGL

• Not interactive, but fast

– VRML• A standard for 3D scene description• Good interactivity (but can be slow)

– PostScript (via DAWN)• Very high quality drawings (suitable for publications)• Can be very slow

Histogramming and AnalisysHistogramming and Analisys

Released version with Lizard using AIDA

1d and 2d histogramsMore than one histogram Single or multiple viewsRun-based or event-basedMessenger to choose modality

Histogramming and AnalysisHistogramming and Analysis

User InterfaceUser Interface

Possibility to modify geometry and materials

Source generation algoritmhs (Particle Module, Geant4 methods)

G4 user interface capabilitiesHistograms operations

AGILE & GLASTAGILE & GLAST

Real Gamma Ray Experiments

XML and Detector DescriptionXML and Detector Description

GLAST collaboration has adopted the XML language for detector description

In house DTD (derived by ATLAS one, but with a lot of modifications)

In house C++ package to interface to the XML file – Lot of clients for this package

• GEANT4• VRML• Event Display• Others ...

XMLXML