introduction using geant4 a simple example my work...

a free software package for the simulation ofparticle-interactions with material and electromagnetic fields

my work & outlookoo

GEANT4 software package Christoph Tenzer - IAAT

Christoph Tenzer – IAATGruppenseminar SS 2005

02.06.2005

a simple example oooooo

using Geant4oooooo

introductionoo

GEANT4

introduction

Christoph Tenzer - IAAT

introductionoo

Geant has been...

a FORTRAN software library package with functions for GEneration ANd Tracking of particles

developed by CERN and KEK

used for simulating interactions of particles colliding with target materials

Geant4 is now...

a huge C++ software project

an international collaboration of physicists and software engineers from Europe, Japan, Canada and the US

a common tool used in nuclear, accelerator, space and medical physics

the largest Monte-Carlo simulation of physical processes with respect to size of the code and the number of contributors

GEANT4 software package

using Geant4oooooo


my work & outlookoo

introduction


introductionoo


Geant has been...

a FORTRAN software library package with functions for GEneration ANd Tracking of particles

developed by CERN and KEK

used for simulating interactions of particles colliding with target materials

Geant4 is now...

a huge C++ software project

an international collaboration of physicists and software engineers from Europe, Japan, Canada and the US

a common tool used in nuclear, accelerator, space and medical physics

the largest Monte-Carlo simulation of physical processes with respect to size of the code and the number of contributors

using Geant4oooooo


my work & outlookoo

introduction


introductionoo

the geometry of the system

the materials involved

the fundamental particles of interest

the physical processes for particle interactions

tracking particles through materials and electromagnetic fields


analyzation of particle trajectories

generation of event data

visualization of geometry and trajectories

different aspects of a simulation that can be covered using Geant4

using Geant4oooooo


my work & outlookoo

introduction


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using Geant4oooooo


my work & outlookoo

using Geant4


using Geant4oooooo


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Geant4

geometry materials particles physicsprocesses

conditionsetup


my work & outlookoo

using Geant4


using Geant4oooooo


introductionoo


conditionsetup

Geant4

detectorconstruction

physicslist

initialconditions

user program


my work & outlookoo

using Geant4


using Geant4oooooo


introductionoo


conditionsetup

Geant4


physicslist

initialconditions

generatedevents visualization

simulationuser program


my work & outlookoo

using Geant4


using Geant4oooooo


introductionoo

Geant4


conditionsetup

geometry

choose from a library of predefined solids (box, torus, cones, cylinders, etc.)create extrusion, rotation, boolean and BREPS objects

example: G4Tube* my_tube = new G4Tube ( „my_tube“,innerRadius,outerRadius,height,startAngle,spanAngle);


my work & outlookoo

using Geant4


using Geant4oooooo


introductionoo

Geant4


conditionsetup

materials

choose from a library of preconstructed elements, isotopes and materialscreate new materials characterized through density, pressure, temperature, chemical composition, etc.

example: density = 27.*mg/cm3;pressure = 50.*atmosphere;temperature = 325. *kelvin;G4Material* CO2 = new G4Material ( „CO2“, density, nComponents=2,

kStateGas, temperature, pressure);CO2->AddElement(elC, nAtoms=1);CO2->AddElement(elO, nAtoms=2);


my work & outlookoo

using Geant4


using Geant4oooooo


introductionoo

materials

choose from a library of preconstructed elements, isotopes and materialscreate new materials characterized through density, pressure, temperature, chemical composition, etc.

example: density = 27.*mg/cm3;pressure = 50.*atmosphere;temperature = 325. *kelvin;G4Material* CO2 = new G4Material ( „CO2“, density, nComponents=2,

kStateGas, temperature, pressure);CO2->AddElement(elC, nAtoms=1);CO2->AddElement(elO, nAtoms=2);


Geant4


conditionsetup

my work & outlookoo

using Geant4


using Geant4oooooo


introductionoo

Geant4


conditionsetup

particles

select relevant particles from a library of predefined particle classes:

- lepton- meson- baryon- boson- shortlived- ion


my work & outlookoo

Image by Contemporary Physics Education Project

using Geant4


using Geant4oooooo


introductionoo

Geant4


conditionsetup

physics processes

select relevant processes from these seven major categories:

- electromagnetic- hadronic- transportation- decay- optical- photolepton_hadron- parameterisation


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Pions and muons emerge from a collision. Picture by CERN.

using Geant4


using Geant4oooooo


introductionoo

Geant4


conditionsetup

condition setup

associate created geometry volumes with their materials

place and rotate volumes inside „world volume“

setup „particle gun“ and/or diffuse background


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ATLAS experiment in the LHC. Picture by CERN.

a simple example


using Geant4oooooo


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detector construction

liquid argon calorimeter:

simulation of 20 layers alternating lead and liquid argon

high-energy particles induce showers of other particles in the lead

as charged secondary particles travel through the argon they cause ionization that is then measured



initialconditions

user program

physicslist

my work & outlookoo

Image of H1 Calorimeter at DESY


using Geant4oooooo


introductionoo



initialconditions

user program

physicslist

my work & outlookoo

a simple example

physics list

particles considered in this example:

leptons: electron, positron, muons, neutrinosmesons: pions, etas, kaonsbaryons: protons, antiprotons, neutronsbosons: photons

relevant processes:

ComptonScattering, GammaConversion, PhotoElectricEffect, eIonisation, Bremsstrahlung, eplusAnnihilation, MuIonisation, MuBremsstrahlung, MuPairProduction


using Geant4oooooo


introductionoo

initial conditions

place calorimeter at desired coordinates in „world volume“

setup „particle gun“:

10 electrons with energy = 50 MeV headed towards the calorimeter



initialconditions

user program

physicslist

my work & outlookoo

a simple example


using Geant4oooooo


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event data

events and tracking are written to a logfile

********************************************************************************************************** G4Track Information: Particle = gamma, Track ID = 63, Parent ID = 41*********************************************************************************************************Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 -6.7 cm -658 mum -1.71 mm 254 keV 0 eV 0 fm 0 fm Lead initStep 1 -6.5 cm -651 mum -3.52 mm 254 keV 0 eV 2.66 mm 2.66 mm Lead Transportation 2 -6 cm -633 mum -8.14 mm 254 keV 0 eV 6.81 mm 9.46 mm liquidArgon Transportation 3 -5.87 cm -628 mum -9.3 mm 239 keV 0 eV 1.72 mm 1.12 cm Lead compt 4 -5.87 cm -652 mum -9.37 mm 0 eV 88 keV 76.5 mum 1.13 cm Lead phot

********************************************************************************************************** G4Track Information: Particle = e-, Track ID = 69, Parent ID = 63*********************************************************************************************************Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 -5.87 cm -652 mum -9.37 mm 151 keV 0 eV 0 fm 0 fm Lead initStep 1 -5.87 cm -653 mum -9.37 mm 0 eV 151 keV 53.1 mum 53.1 mum Lead eIoni


results


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a simple example


using Geant4oooooo


introductionoo

visualization

geometry and particle tracks can be visualized using various drivers:

OpenGL, WIRED, DAWN, etc.


results


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a simple example

Result of this simple example

Geant4 simulation of ATLAS at CERN

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introductionoo


using Geant4oooooo


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wrap up:

components that make up a Geant4 simulation

simulation capabilities of Geant4

current state:

built and stepped through the relevant tutorials

tried a few geometries and materials on my own

current & future work:

starting to simulate a known detector in a typical environment

simulating, understanding and optimizing the properties of stacked detectors

my work & outlook


introductionoo


using Geant4oooooo


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wrap up:






current state:



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using Geant4oooooo


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current state:






Mechanical arrangement of the XEUS focal plane (XEUS Instrument Working Group)

introduction using geant4 a simple example my work...

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