$Id: README,v 1.11 2009/09/22 15:18:20 maire Exp $
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     =========================================================
     Geant4 - an Object-Oriented Toolkit for Simulation in HEP
     =========================================================

                            TestEm12
                            --------


     How to plot a depth dose profile in spherical geometry.        

	
 1- GEOMETRY DEFINITION
 
	The geometry consists of a single sphere of an homogenous material.
	Optionally, the sphere can be divided in thin shells.
     	
	3 parameters define the geometry :
 	- the material of the sphere,
	- the radius of the sphere (absorRadius),
	- the number of shells (nbOfLayers)
	 	
 	In addition a transverse uniform magnetic field can be applied.
 	
 	The default geometry is constructed in DetectorConstruction class,
 	but all of the above parameters can be changed interactively via
 	the commands defined in the DetectorMessenger class.
 	
 2- PHYSICS LIST
 
 Physics lists can be local (eg. in this example) or from G4 kernel
 physics_lists subdirectory.
     
 Local physics lists:	 
 - "local"	standard EM physics with current 'best' options setting.
			
 From geant4/source/physics_lists/builders:	 
  - "emstandard_opt0" recommended standard EM physics for LHC
  - "emstandard_opt1" best CPU performance standard physics for LHC
  - "emstandard_opt2"     
  - "emstandard_opt3" best current advanced EM options. 
                      analog to "local" above  
  - "emlivermore"  low-energy EM physics using Livermore data
  - "empenelope"   low-energy EM physics implementing Penelope models
      
 Physics lists and options can be (re)set with UI commands
    
 Please, notice that options set through G4EmProcessOPtions are global, eg
 for all particle types. In G4 builders, it is shown how to set options per
 particle type.

 	 
 3- AN EVENT : THE PRIMARY GENERATOR
 
 	The primary kinematic consists of a single particle randomly shooted at
	the centre of the sphere. The type of the particle and its energy are set 
 	in the PrimaryGeneratorAction class, and can be changed via the G4 
 	build-in commands of ParticleGun class (see the macros provided with 
 	this example).
	
 	In addition one can desactivate the randomness of the direction of the 
	incident particle. The corresponding interactive command is built in
 	PrimaryGeneratorMessenger class.
	 	
 	A RUN is a set of events.
 	
 				
 4- VISUALIZATION
 
 	The Visualization Manager is set in the main().
 	The initialisation of the drawing is done via the commands
 	/vis/... in the macro vis.mac. To get visualisation:
 	> /control/execute vis.mac
 	
 	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.
 	Optionaly one can choose to draw all particles, only the charged one,
 	or none. This command is defined in EventActionMessenger class.
 	
 	
 5- HOW TO START ?
 
 	- compile and link to generate an executable
 		% cd geant4/examples/extended/electromagnetic/TestEm1
 		% gmake
 		
 	- execute TestEm12 in 'batch' mode from macro files
 		% TestEm12   run01.mac
 		
 	- execute TestEm12 in 'interactive mode' with visualization
 		% TestEm12
 		....
 		Idle> type your commands
 		....
 		Idle> exit
		
 6- TRACKING  and STEP MAX
 
     Testem12 computes the total energy deposited along the trajectory of 
     the incident particle : the so-called longitudinal energy profile,
     or depth dose distribution.
     The energy deposited (edep) is randomly distribued along the step (see
     SteppingAction).
     
     In order to control the accuracy of the deposition, the maximum  step size 
     of charged particles is computed automatically from the binning of 
     histograms 1 and 8 (see HistoManager).
     
     As an example, this limitation is implemented as a 'full' process :
     see StepMax class and its Messenger. The 'StepMax process' is registered
     in the Physics List.
     
     In RunAction::BeginOfRun() the stepMax value is passed from the 
     HistoManager to the StepMax process. 
     A boolean UI command allows to desactivate this mechanism.
     	
 7- HISTOGRAMS
 
   Testem12 has several predefined 1D histograms : 
  
      1 : energy profile dE/dr (in MeV/mm per event)
      2 : total energy deposited in the absorber
      3 : total track length of the primary track
      4 : step size of the primary track      
      5 : projected range of the primary track
      6 : total track length of charged secondary tracks
      7 : step size of charged secondary tracks      
      8 : normalized energy profile d(E/E0)/d(r/r0), where r0 is the range of
          the primary particle of energy E0
            
   The histograms are managed by the HistoManager class and its Messenger. 
   The histos can be individually activated with the command :
   /testem/histo/setHisto id nbBins  valMin valMax unit 
   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:
   /testem/histo/setFileName  name  (default testem12)
   
   It is possible to choose the format of the histogram file (hbook, root, XML)
   with the command /testem/histo/setFileType (root by default)
   
   It is also possible to print selected histograms on an ascii file:
   /testem/histo/printHisto id
   All selected histos will be written on a file name.ascii  (default testem12) 
        
   Note that, by default, histograms are disabled. To activate them, uncomment
   the flag G4ANALYSIS_USE in GNUmakefile.
   
 
 8- USING HISTOGRAMS

  To use histograms, at least one of the AIDA implementations should be 
  available. See InstallAida.txt
