Geant4 Example B1 for Tracking

Description

This is a simple Geant4 program for particle tracking modified from Example B1 (basic), and is an assignment for the Dark Photon Software Workshop (19–21 January 2024).

For (possible) future data analysis, the hit information are stored, including position, energy deposition, and momentum, where the momentum is calculated in natural units ($c = 1$), using formula

$$ p = \frac{mv}{\sqrt{1 - v^2}}. $$

For hit information, the units are default: position in mm, time in ns, and momentum and energy in MeV.

Geometry

The tracker consists of 7 layers of silicon, separated 30 centimetres apart along $z$ axis, each with size 200 × 100 × 0.1 mm³.

Environment Set-up

This project requires CMake version >= 2.6. If you are working on the cluster of INPAC, IHEP, etc., the environment can be easily set up by executing

source /cvmfs/sft.cern.ch/lcg/views/LCG_97rc4python3/x86_64-centos7-gcc9-opt/setup.sh

Then, the environment with CMake 3.14.3, Geant4-10.06-patch-01, and ROOT 6.20/00 is configured. As long as no compilation errors are raised and the CMake version requirement is met, other versions on the LCG are also acceptable (mind your version of Geant4!). 😛

Installation & Compilation

Having set up the environment, this project can be cloned from GitHub and compiled normally:

git clone git@github.com:phys-jychen/tracking-B1.git
cd tracking-B1
mkdir build
cd build
cmake ..
make -j100    # Just do it!
source setup.sh

Usage

In command line, and in the build directory, running

./exampleB1

leads you to the UI, where the default particle is 100-MeV proton. The particle source can also be easily set through the UI.

It is also recommended to prepare a .mac macro (e.g. run.mac) and execute through

./exampleB1 run.mac

if you need to generate more MC samples and save data for future analysis.

Have fun! ☺️