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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 are based on modular design. Several modules are instantiated:
  1. Transportation
  2. EM physics
  3. Decays
  4. StepMax - for step limitation
 
  The following options for EM physics using builders from physics_lists
  sub-package are available:
  - "emstandard_opt0" recommended standard EM physics for LHC
  - "emstandard_opt1" best CPU performance standard physics for LHC
  - "emstandard_opt2" similar fast simulation
  - "emstandard_opt3" best standard EM options - analog to "local" above
  - "emstandard_opt4" best current advanced EM options standard + lowenergy
  - "emstandardWVI" standard EM physics and WentzelVI multiple scattering
  - "emstandardSS"  standard EM physics and single scattering model
  - "emstandardGS"  standard EM physics and Goudsmit-Saunderson multiple scatt.
  - "emlivermore"  low-energy EM physics using Livermore data
  - "empenelope"   low-energy EM physics implementing Penelope models
  - "emlowenergy"  low-energy EM physics implementing experimental
                   low-energy models
  - "dna"          process and models for Geant4-DNA
  - "dna_opt1"     process and models for Geant4-DNA
  - "dna_opt2"     process and models for Geant4-DNA
  - "dna_opt3"     process and models for Geant4-DNA
  - "dna_opt4"     process and models for Geant4-DNA
  - "dna_opt5"     process and models for Geant4-DNA
  - "dna_opt6"     process and models for Geant4-DNA
  - "dna_opt7"     process and models for Geant4-DNA
 
  A local builder, PhysListEmStandard "local" (similar to opt0) is also
  available.
 
  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 shot 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 
 	built-in commands of ParticleGun class (see the macros provided with 
 	this example).
	
 	In addition one can deactivate 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.
 	Optionally one can choose to draw all particles, only the charged ones,
 	or none. This command is defined in EventActionMessenger class.
 	
 5- HOW TO START ?
 
 	- 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
 
     TestDm12 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 distributed 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 RunAction).
     
     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.
     
     StepMax is evaluated in RunAction::BeginOfRun() and passed 
     to the StepMax process. 
     A boolean UI command allows to deactivate this mechanism.
     Another UI command allows to define directly a stepMax value.
      	
 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 G4AnalysisManager class and its Messenger. 
   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, deg or mrad, etc..)
   
   One can control the name of the histograms file with the command:
   /analysis/setFileName  name  (default testem12)
    
   It is possible to choose the format of the histogram file : root (default),
   xml, csv, by using namespace in HistoManager.hh      
   
   It is also possible to print selected histograms on an ascii file:
   /analysis/h1/setAscii id
   All selected histos will be written on a file name.ascii  (default testem12) 
