geant4

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 		  Geant4 - mfp example
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                                README file
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                           CORRESPONDING AUTHOR 

S. Incerti et al. (a, *)
a. Centre d'Etudes Nucleaires de Bordeaux-Gradignan 
(CENBG), IN2P3 / CNRS / Bordeaux University, 33175 Gradignan, France
* e-mail:incerti@cenbg.in2p3.fr

---->0. 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.

These 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:
Phys. Med. 31 (2015) 861-874
Med. Phys. 37 (2010) 4692-4708

---->1. 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 and 
energy can be controlled by the mfp.in macro file.

---->2. 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.

---->3. 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.

---->4. PHYSICS

G4EmDNAPhysics* constructors are used.

---->5. SIMULATION OUTPUT AND RESULT ANALYSIS                                    

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.

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Should you have any enquiry, please do not hesitate to contact: 
incerti@cenbg.in2p3.fr