     =========================================================
     Geant4 - an Object-Oriented Toolkit for Simulation in HEP
     =========================================================


                              Example factory

                             I. Hrivnacova,
Institut de Physique Nucléaire (IPNO), Université Paris-Sud, CNRS-IN2P3
                  Based on Hadr00 by V. Ivantchenko, CERN


Examples in the physicslist category show the possible ways how to define
a physics list from Geant4 physics constructors. This example demonstrates 
the usage of G4PhysListFactory to build  the concrete physics list.

Physics List can be defined by its name given by the -p argument of the of the 
run command or by  the PHYSLIST environment variable. 

./factory -m my.macro [ -p QGSP_BERT ]    

By default, FTFP_BERT Physics List will be instantiated if 
-p argument is not set and the PHYSLIST environment variable is not defined.

The same experimental setup is used for all examples in the physicslist category:

1- Detector description
-----------------------

The geometry (defined in the DetectorConstruction class) consists in a box of scintillator material (CsI) followed by a thin box of air (screen) which is used to simplify scoring.

 
2- Primary generator
--------------------

The primary generator is defined with usage of G4ParticleGun.
The default particle is proton which hits the box perpendicular to the input face. 
The type of the particle and its energy are set in the PrimaryGeneratorAction class, and can
be changed via the G4 built-in commands of the G4ParticleGun class.

 
3- Scoring (ntuples)
--------------------

The screen volume is associated with a sensitive detector, ScreenSD,
which accounts the following particle properties:
- trackID
- particle PDG encoding
- particle kinetic energy
- particle X,Y position
- particle time

The scored quantities are filled in the Screen ntuple, which is defined using G4AnalysisManager
in RunAction class. The ntuple is saved in a Root file, which name is set to be equal to the
example name in main () function.

4- How to build
---------------- 

An additional step is needed when building the example with GNUmake
due to using the extra shared directory: 
 % cd path_to_example/example
 % gmake setup
 % gmake

This will copy the files from shared in the example include and src;
to remove these files:
 % gmake clean_setup

