Geant4 Particle Phase-space Propagation in a Multi-layer Material

gp3m2 is a Geant4 application created to simulate the particle phase-space propagation in a multi-layer material. It gets a phase space as input, and export particle phase space when a particle cross any layer boundary.

Principle

The phase space contains following informations :

• Particle statistical weight
• Particle position
• Particle momentum
• Time when the particle has cross the boundary

Notes :

• This G4 app was made for my personal use, to simulate propagation of particles created by laser-plasma interaction (simulation done with a Particle-In-Cell code)
• This app is experimental, no warranty about the physical results you may find

Installation

Geant4 build

You first need Geant4 installed with data and multi-threading mode. Build options for the cmake command are:

CMAKE_INSTALL_PREFIX=/path/to/your/install
GEANT4_INSTALL_DATA=ON
GEANT4_BUILD_MULTITHREADED=ON
GEANT4_USE_QT=ON # This is optional, but needed for visualisation

If the GEANT4_USE_QT tag is set, it requires qt5 and openGL librairies (qt5-default package on Ubuntu).

source /path/to/your/install/bin/geant4.sh

gp3m2 build

You can then download the gp3m2 code from github and type the following commands

cd /path/to/gp3m2/
mkdir build
cd build
cmake ../
make

It is possible to use the make command with multi-thread using make -jN, N being the number of threads you want to use.

The bash script compile can also be used to compile the source (when cmake command was done).

Benchmarks

I made some benchmarks in order to validate the method. To launch the benchmark N from the root dir, you can type

./benchmark [N] [v]

To see the Geant4 output in the terminal, use the keyword v as a second argument.

By default the benchmark 0 is launched with no verbose mode.

More informations can be found at benchmarks/README.md.

## Features and usage

Units

...

Geometry

The geometry is

image

It can be managed with macro commands

/target/

InputReader

Diagnostics

Other macro commands

This app uses the G4ParticleGun class to create primary events. You then have access to the /gun/ folder of commands.

In addition to native Geant4 commands, this app also define other commands :

• /target/addLayer material size
• /input/setFileName filename
• /input/setParticle particle
• /output/setFileName filename
• /output/setLowEnergyLimit number unit

Documentation

Geant4 documentation

If you're not familiar with the Geant4 toolkit, you can find documentation here:

gp3m2 documentation

You can generate a html documentation with doxygen (class and methods are documented). In the folder doc/, type

doxygen doxyfile

or use doxywizard.

The code structure is:

Known problems/Remarks

• Infinite statistical weight in diagnostics when the number of events is less than number of lines of the input file (number of configurations)
• Precision of 6 digits in diagnostics (forced by the analysis manager ?)