LArGeant

(Code for simulating TPC experiments with custom geometries and sources in Geant4)

Main Features

• Custom Geometry - Custom geometries can be built by constructing DetectorComponent objects which can be built from radiological materials that LArGeant will automatically simulate as backgrounds in events according to certain run-time parameters.
• Multithreading - LArGeant is built with multithreading in mind, ...
• NEST - Scintillation and ionization is simulated using the NEST software package which can operate in both a liquid/gas phase for argon and xenon.
• Data Products - Several data products are generated at the event level which the user can export to custom analysis code and also save to ROOT files.

Installation

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There are several scripts included with the git respository that will automate the installation process. Once downloaded, go to the scripts folder

git clone https://github.com/infophysics/LArGeant.git
cd LArGeant/scripts

then run the Geant4 preprocessing step, which will install required packages such as cmake, gcc, g++, expat, qt5, xmu and motif:

source prepare_geant4_installation.sh

it will also download a version of geant4 and install it in the directory /home/$USER/physics/geant4/. The next step is to actually install geant4, which can be done with:

source install_geant4.sh

Finally, to compile the largeant code you can run the following script:

source install_largeant.sh

Manual Installation

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If for some reason the installation scripts do not work, or you wish to install Geant4 manually, the following list of steps should work on Ubuntu 20.XX.

• Install Dependencies - First you will need a few packages, such as QT in order to use the visualization tools,

  sudo apt-get install cmake gcc g++ libexpat1-dev qt5-default libxmu-dev libmotif-dev

• Get the code - Now choose a place in which you want to download the Geant4 code. The following should work:

  wget "http://cern.ch/geant4-data/releases/geat4.10.07.p02.tar.gz"
  tar xvfz geant4.10.07.p02.tar.gz
  rm geant4.10.07.p02.tar.gz

• Install Geant4 - The easiest way to install geant4 once you have it downloaded, is to use ccmake, which you may have to download using

  sudo apt-get install cmake-curses-gui

  Next, you should create a build directory inside of the folder where the source code is for building the code:

  cd geant4.10.07.p02
  mkdir build && cd build

  Then just run ccmake, which will bring up a cmake GUI

  ccmake ..

  From here, there are several things that you need to enable, such as GEANT4_INTALL_DATA=ON, GEANT4_USE_QT=ON and GEANT4_USE_SYSTEM_EXPAT=ON. You also need to specify the installation directory, which in the scripts is set to /home/$USER/physics/geant4.10.07.p02-install/. If you are not using ccmake, but instead just running cmake from the build directory, you can do this with the following:

  cmake -DCMAKE_INSTALL_PREFIX=<install_dir> -DGEANT4_INSTALL_DATA=ON -DGEANT4_USE_QT=ON -DGEANT4_USE_SYSTEM_EXPAT=ON ..

  If cmake is successful, you can then build the project by issuing

  make -j N
  make install

  where N is the number of cores you want to use to build.
• Post-insallation - Once installed, you will need to run a setup script to export the right environment variables. This can be found in the folder <install_dir>/share/Geant4*/geant4make/:

  source <install_dir>/share/Geant4\*/geant4make/geant4make.sh