//$Id$

///\file "parallel/TopC/ParN02/.README.N02.txt"
///\brief Example N02 (in ParN02) README page

/*! \page ExampleN02InParN02 Example N02 in ParN02 
			    

 This example simulates a simplified fixe target experiment.
 Read \link ExampleParN02 Example ParN02 \endlink for a description 
 of how to run it in parallel.

\section ExampleN02InParN02_s1 GEOMETRY DEFINITION
 
 The setup consists of a target followed by six chambers of increasing
 transverse size. These chambers are located in a region called Tracker
 region. Their shape are boxes, constructed as parametrised volumes
 (ChamberParametrisation class).
 
 The default geometry is constructed in DetectorConstruction class.
 One can change the material of the target and of the chambers
 interactively via the commands defined in the DetectorMessenger class.
 
 In addition a transverse uniform magnetic field can be applied (see
 N02MagneticField and DetectorMessenger classes). 
 
         
\section ExampleN02InParN02_s2 PHYSICS LIST
 
 The particle's type and the physic processes which will be available
 in this example are set in PhysicsList class.
 
 In this example, all the so called 'electromagnetic processes' are
 introduced for gamma, charged leptons, and charged hadrons (see the
 method PhysicsList::ConstructEM()). 
 
 An important data member of this class is the defaultCutValue which
 defines the production threshold of secondary particles
 (mainly Ionisation and Bremsstrahlung processes are concerned by this
 CutValue).
 Notice that the CutValue must be given in unit of length, corresponding
 to the stopping range of the particle. It is automatically converted
 in energy for each material, and a table is printed in the method
 PhysicsList::SetCuts() 
 
 In addition the build-in interactive command:
\verbatim     
/process/(in)activate processName
\endverbatim     
 allows to activate/inactivate the processes one by one.


\section ExampleN02InParN02_s3 RUNS and EVENTS
 
 The primary kinematic consists of a single particle which hits the
 target 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 build-in commands of ParticleGun class.

  A RUN is a set of events.
  
  The user has control:
     -at Begin and End of each run (class RunAction)
     -at Begin and End of each event (class EventAction)
     -at Begin and End of each track (class TrackingAction, not used here)
     -at End of each step (class SteppingAction)

 The class SteppingVerbose prints some informations step per step,
 under the control of the command: /tracking/verbose 1
 It inherits from G4SteppingVerbose, and has been setup here in order
 to illustrate how to extract informations from the G4 kernel during
 the tracking of a particle.
    	
	
\section ExampleN02InParN02_s4 DETECTOR RESPONSE
 
 A HIT is a record, track per track (even step per step), of all the 
 informations needed to simulate and analyse the detector response.
 
 In this example the Tracker chambers are considered as the detector.
 Therefore the chambers are declared 'sensitive detectors' (SD) in
 the DetectorConstruction class. 
 
 Then, a Hit is defined as a set of 4 informations per step, inside 
 the chambers, namely:
    - the track identifier (an integer),
    - the chamber number,
    - the total energy deposit in this step,
    - the position of the deposit.

 A given hit is an instance of the class TrackerHit which is created
 during the tracking of a particle, step by step, in the method
 TrackerSD::ProcessHits(). This hit is inserted in a HitsCollection. 
 
 The HitsCollection is printed at the end of event (via the method 
 TrackerSD::EndOfEvent()), under the control of the command: /hits/verbose 1

 				
\section ExampleN02InParN02_s5 VISUALIZATION
 
 The Visualization Manager is set in the main () (see exampleN02.cc).
 The initialisation of the drawing is done via a set of /vis/ commands
 in the macro vis.mac. This macro is automatically read from 
 the main when running in interactive mode.
 
 The tracks are automatically drawn at the end of event and erased at 
 the beginning of the next run.

 The visualization (with OpenGL driver) assumes two things:
    1- the visualisation & interfaces categories have been compiled
           with the environment variable G4VIS_BUILD_OPENGLX_DRIVER.
    2- ParN02.cc has been compiled with G4VIS_USE_OPENGLX.   

 (The same with DAWNFILE instead of OPENGLX)
     
     
\section ExampleN02InParN02_s6 USER INTERFACES
  
 The default command interface, called G4UIterminal, is done via
 standart cin/G4cout.
 On Linux and Sun-cc on can use a smarter command interface G4UItcsh.
 It is enough to set the environment variable G4UI_USE_TCSH before
 compiling ParN02.cc
 
*/
