Pi-SP_sim

Geant4 simulation for studying target stopping power with a pi-(momentum 70.5 MeV/c) beam, used in MEG II collaboration

How to run the program

Starting from the project directory:

Pi-SP_sim $ mkdir build
Pi-SP_sim $ cd build

Now we can compile the project:

Pi-SP_sim/build $ cmake ..
Pi-SP_sim/build $ make

Options

To have a full preview on how to run the program, simply write:

Pi-SP_sim/build $ ./sim help

 Pi-SP_sim Help:

Pi-SP_sim/build $ ./sim [command] [option]

             - Simulation starts in GUI mode
         vis - Simulation starts in GUI mode
  beamOn [x] - Simulation starts in batch mode, executing macro /run/beamOn [x],
               where [x] is an integer passed as input (if not, defalut is [x] = 100)

E.g.: to run in batch mode with 1000 events, write:

Pi-SP_sim/build $ ./sim beamOn 1000

ROOT output

As default, everytime a run is started, the program will make a file output.root in the build folder. The file contains the following TNtuples:

1. FDet: information about the $\pi^-$ in the first detector.
   • fEvents (int): ID number of the event.
   • fX (double): X position of the $\pi^-$.
   • fY (double): Y position of the $\pi^-$.
   • fZ (double): Z position of the $\pi^-$.
2. LH2: information about the process occurred at the end of the $\pi^-$ life in the LH2 target.
   • fProc (string): name of the occurred process.
   • fX (double): final X position of the $\pi^-$.
   • fY (double): final Y position of the $\pi^-$.
   • fZ (double): final Z position of the $\pi^-$.

The user can analyze the results contained in the file using the two scripts plot_3d.py and plot_LH2.cc in the project folder, or simply open a ROOT terminal to explore the file with a TBrowser.