//$Id$

///\file "electromagnetic/TestEm14/.README.txt"
///\brief Example TestEm14 README page

/*! \page ExampleTestEm14 Example TestEm14

  - How to compute cross sections from the direct evaluation of the mean
    free path ( see below, \ref TestEm14_s4).
  - How to plot final state of a process.   
  
\section TestEm14_s1 GEOMETRY DEFINITION
 
  It is a single box representing a 'semi infinite' homogeneous medium.
  Two parameters define the geometry :
  - the material of the box,
  - the (full) size of the box.
   
  The default geometry (100 m of water) is constructed in 
  DetectorConstruction, but the above parameters can be changed 
  interactively via the commands defined in DetectorMessenger.
   
\section TestEm14_s2 PHYSICS LIST
 
  The physics list contains the standard electromagnetic processes.
  In order not to introduce 'artificial' constraints on the step size, the
  multiple scattering is not instanciated, and all processes are
  registered as discrete : there is no continuous energy loss.  
    
\section TestEm14_s3 AN EVENT : THE PRIMARY GENERATOR
 
  The primary kinematic consists of a single particle starting at the edge
  of the box. The type of the particle and its energy are set in 
  PrimaryGeneratorAction (1 MeV gamma), and can be changed via the G4 
  build-in commands of G4ParticleGun class (see the macros provided with 
  this example).
   
\section TestEm14_s4 PHYSICS
 
  An event is killed at the first interaction of the incident paticle.
  The absorption length, also called mean free path, is computed as 
  the mean value of the track length of the incident particle.
  This is why the medium must be 'infinite' : to be sure that interaction
  occurs at any events.
  
  The result is compared with the 'input' data, i.e. with the cross
  sections stored in the PhysicsTables and used by Geant4.
  
  The energy spectrum and the angular distribution of the scattered
  particle (if any) and of the created secondaries are plotted (see
  SteppingAction).
   
  A set of macros defining various run conditions are provided.
  The processes are actived/inactived in order to survey the processes 
  individually.

\section TestEm14_s5 HISTOGRAMS
         
  The test contains 6 built-in 1D histograms, which are managed by the
  HistoManager class and its messenger, HistoMessenger. The histos can be individually 
  activated with the command :
  /analysis/h1/set id nbBins  valMin valMax unit 
  where unit is the desired unit for the histo (MeV or keV, etc..)
  (see the macros xxxx.mac).
 
   - 1 :     "scattered primary particle: energy spectrum"
   - 2 :     "scattered primary particle: costheta distribution"
   - 3 :     "charged secondaries: energy spectrum"
   - 4 :     "charged secondaries: costheta distribution"
   - 5 :     "neutral secondaries: energy spectrum"
   - 6 :     "neutral secondaries: costheta distribution"      
      
   The histograms are managed by the HistoManager class and its messenger, 
   HistoMessenger 
   The histos can be individually activated with the command :
\verbatim
/analysis/h1/set id nbBins  valMin valMax unit 
\endverbatim
   where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
   
   One can control the name of the histograms file with the command:
\verbatim
/analysis/setFileName  name  (default testem14)
\endverbatim
   
   It is possible to choose the format of the histogram file : root (default),
   hbook, xml, csv, by using namespace in HistoManager.hh
       
   It is also possible to print selected histograms on an ascii file:
\verbatim
/analysis/h1/setAscii id
\endverbatim
   All selected histos will be written on a file name.ascii (default testem14) 
    
\subsection TestEm14_sub_s51 Using hbook format
 
 Need a special treatement : the Cern Library must be installed and the
 environment variable CERNLIB correctly set. Then, *before* compiling,
 activate G4_USE_HBOOK in GNUmakefile and g4hbook.hh in HistoManager.hh
            
\section TestEm14_s6- VISUALIZATION
 
   The Visualization Manager is set in the main () (see TestEm14.cc).
   The initialisation of the drawing is done via the commands
   /vis/... in the macro vis.mac. To get visualisation:
\verbatim
> /control/execute vis.mac
\endverbatim
   
   The detector has a default view which is a longitudinal view of the 
   box.
   
   The tracks are drawn at the end of event, and erased at the end of run.
  
\section TestEm14_s7- HOW TO START ?
 
  - Execute TestEm14 in 'batch' mode from macro files :
\verbatim
% TestEm14   compt.mac
\endverbatim
    
  - Execute TestEm14 in 'interactive mode' with visualization :
\verbatim
% TestEm14
Idle> control/execute vis.mac
....
Idle> type your commands
....
Idle> exit
\endverbatim
  
*/
  
