Gabriele Cosmo\page Examplemfp Example mfp
\author S. Incerti et al. (a, *) \n a. LP2i, IN2P3 / CNRS / Bordeaux University, 33175 Gradignan, France \n
- e-mail:incerti@lp2ib.in2p3.fr
INTRODUCTION.
The mfp example shows how to calculate mean free path of particles in liquid water using the Geant4-DNA physics processes and models.
It has been adapted from the spower and TestEm14 examples.
This example is provided by the Geant4-DNA collaboration.
The Geant4-DNA processes and models are further described at: http://geant4-dna.org
Any report or published results obtained using the Geant4-DNA software shall cite the following Geant4-DNA collaboration publications: \n Med. Phys. 51 (2024) 5873–5889 \n Med. Phys. 45 (2018) e722-e739 \n Phys. Med. 31 (2015) 861-874 \n Med. Phys. 37 (2010) 4692-4708 \n Int. J. Model. Simul. Sci. Comput. 1 (2010) 157–178
GEOMETRY SET-UP
The geometry is a 1 m radius sphere of liquid water (G4_WATER material). Particles are shot along x from the sphere centre.
Radius of the sphere, physics constructor, primary particle type and energy can be controlled by the mfp.in macro file.
SET-UP
Make sure G4LEDATA points to the low energy electromagnetic data files.
The code can be compiled with cmake.
It works in MT mode.
HOW TO RUN THE EXAMPLE
Use:
./mfp mfp.in
The mfp.in macro allows a full control of the simulation.
The computation of MFP and other quantities is performed in the SteppingAction::UserSteppingAction method.
The histo.in macro shows how to display several quantities (energy spectrum, scattering angle along x) of primary and secondaries.
PHYSICS
G4EmDNAPhysics* constructors are used.
SIMULATION OUTPUT AND RESULT ANALYSIS
The accuracy of results may depend on incident statistics as well as on number of steps specified in the SteppingAction::UserSteppingAction method.
The output results consist in a text file (mfp.txt), containing:
- energy of incident particles (in eV)
- mfp (in nm)
- rms (i.e. standard deviation) on mfp (in nm)
Otherwise you may use histo.in to generate ROOT histograms of the other quantities.