///\file "electromagnetic/TestEm16/.README.txt"
///\brief Example TestEm16 README page

/*! \page ExampleTestEm16 Example TestEm16

 Simulate synchrotron radiation
	
\section TestEm16_s1 GEOMETRY DEFINITION

 The geometry consists of a single block of a homogenous material.

 Two parameters define the geometry :
    - the material of the box,
    - the (full) size of the box.
 The default is 500 m of vacuum.

 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.

\section TestEm16_s2 PHYSICS LIST

 The particle list include EM processes for gamma, e+, e-, mu+, mu-,
 and protons, for the rest of particles only transportation.
 Synchrotron radiation is added to all charged particles.
 To make the synchrotron radiation easily visible, a very low
 pressure "vaccuum" and a magnetic field of by default 1 Tesla
 in z-direction is used.

\section TestEm16_s3- AN EVENT : THE PRIMARY GENERATOR

 The primary kinematic consists of a single particle which hits the
 block perpendicular to the input face. The type of the particle
 and its energy are set in the PrimaryGeneratorAction class, and can
 changed via the G4 build-in commands of ParticleGun class (see
 the macros provided with this example).
 The default is an positron of 10 GeV.
    
 In addition one can choose randomly the impact point of the incident
 particle. The corresponding interactive command is built in
 PrimaryGeneratorMessenger class.
            
 A RUN is a set of events.

\section TestEm16_s4 VISUALIZATION

 The Visualization Manager is set in the main () (see TestEm16.cc).
 The initialisation of the drawing is done via the command
\verbatim
> /control/execute vis.mac
> /run/beamOn 1
\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.
 Optionaly one can choose to draw all particles, only the charged one,
 or none. This command is defined in EventActionMessenger class.

\section TestEm16_s5 PHYSICS DEMO

 The particle's type and the physic processes which will be available
 in this example are set in PhysicsList class.

 In addition a build-in interactive command (/process/inactivate proname)
 allows to activate/inactivate the processes one by one.

 The threshold for producing secondaries can be changed.
 eg: 
\verbatim
 /run/setCut 100 micrometer
 /run/initialize
\endverbatim
	
 To visualize the Synchrotron radiation :
\verbatim
/control/execute vis.mac
\endverbatim
		  	
\section TestEm16_s6- HOW TO START ?

 - execute Test  in 'batch' mode from macro files
\verbatim
% TestEm16    run01.mac
\endverbatim

 - execute Test  in 'interactive mode' with visualization
\verbatim
% TestEm16
	....
Idle> type your commands
	....
Idle> exit
\endverbatim

 other Macros provided in this example:
   - run01_prot.mac
     Synchrotron radiation of 50 TeV protons in 20 T field
     relevant for FCC-hh
   - run02.mac
     weak field long distance example
     relevant for space applications
   - TestReflection.mac
     specular reflection of X-ray gammas on a block of
     copper defined by Box_1m_Cu.gdml

\section TestEm16_s7 TRACKING : stepMax and setMaxStepLength

  In order to control the accuracy of the deposition, the user can limit
  'by hand' the maximum  step size stepMax of charged particles.

  The maximum tracking step length for computing of magnetic field lines
  is by default set to 1 km.
  Synchrotron radiation in very weak magnetic fields of the order of 1 Gauss
  may require longer pathlength.
  This can be achieved with using setMaxStepLength like
\verbatim
/testem/tracking/setMaxStepLength 100 km
\endverbatim

\section TestEm16_s8 HISTOGRAMS

  TestEm16 produces 3 histograms which illustrate synchrotron radiation.
  The photon energy spectrum (photons / energy bin) and the power spectrum
  (photon spectrum weighted with the photon energy) and a histogram
  of the path length between photon radiation is produced.
	 
  The histograms are managed by G4AnalysisManager and its Messenger.
     	
  The histos can be activated individually 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, cm or mm, etc..)
								  
  One can control the name of the histograms file with the command:
\verbatim
/analysis/setFileName  name  (default testem16)
\endverbatim
   
  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:
\verbatim
/analysis/h1/setAscii id
\endverbatim
  All selected histos will be written on a file name.ascii  (default testem16)
  
*/
