G4BeamTest is a C++ simulation of an Optical Module Beam Test at the Fermilab Test Beam Facility (FTBF).

• Optical Module Beam Test at the FTBF
• Installation
  • Dependencies
• Running G4BeamTest
• License

In this beam test, a tank was filled with distilled water, upon which an Optical Module in a glass housing was floating, observing Cherenkov light inside the tank (see below schematic). The goal was to study and confirm if pulse shape information can be used for particle identification (PID) between pions and electrons in the context of future water or ice Cherenkov neutrino telescope experiments. For more details, see the paper "Pulse Shape Particle Identification by a Single Large Hemispherical Photo-Multiplier Tube" - S. Samani, S. Mandalia, C. Argüelles, S. Axani, Y. Li, M.H. Moulai, B. Ty, Z. Xie, J. Conrad, T. Katori, P. Sandstrom.

G4BeamTest can be installed using cmake

mkdir build && cd build
cmake -DGEANT4_USE_QT=ON ../
make

G4BeamTest has the following dependencies:

• gcc-c++
• CMake >= 2.6
• Geant4 >= 10.4

For installation instructions of Geant4 see the Geant4 Installation Guide. All G4 data files including hadron cross-sections are required to be downloaded. Here is a typical example of the environment variables which need to be set in your .bash_profile:

export GEANTTOPDIR="/opt/geant4"
export G4LEVELGAMMADATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/PhotonEvaporation5.2"
export G4NEUTRONXSDATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/G4NEUTRONXS1.4"
export G4LEDATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/G4EMLOW7.3"
export G4NEUTRONHPDATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/G4NDL4.5"
export G4ENSDFSTATEDATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/G4ENSDFSTATE2.2"
export G4RADIOACTIVEDATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/RadioactiveDecay5.2"
export G4ABLADATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/G4ABLA3.1"
export G4PIIDATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/G4PII1.3"
export G4SAIDXSDATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/G4SAIDDATA1.1"
export G4REALSURFACEDATA="$GEANTTOPDIR/share/Geant4-10.4.2/data/RealSurface2.1.1"
export LD_LIBRARY_PATH=$GEANTTOPDIR/lib64:$LD_LIBRARY_PATH
export PATH=$GEANTTOPDIR/bin:$PATH

Additional dependencies:

• Qt >= 4

Be sure to install with Qt support for the GUI interface shown in the image above.

To test the installation is working, run the test macro run1.mac, which will generate 10 electrons with an energy of 2 GeV and fire them into the tank. In the build folder, run

./G4BeamTest -m run1.mac -n test_2GeV_e.txt

For each electron, if it manages to pass through the tank and is detected in the downstream scintillator (SC4), the number of Cherenkov photons that hit the underside of the Optical Module glass shell is recorded in the output file specified by the -n flag.

To run with the GUI Qt application simply run

./G4BeamTest

MIT License

Copyright (c) 2020 Shivesh Mandalia