
///\file "field/field02/.README.txt"
///\brief Example field02 README page

/*! \page Examplefield02 Example  field02

 Test for investigation of tracking in electric field
 and field dependent electromagnetic processes.

\section field02_s0 FIELD DEFINITION
 The field is a constant electric field.

 Technical note: in order to use any electric field, it is
 necessary to create the objects for its equation of motion,
 the stepper and driver for the integration, and the
 chord finder.

 The class that does these is G4FieldBuilder. Its object
 is created in the F02DetectorConstruction constructor and 
 its instantiation adds the /field UI commands that allow user
 to choose the field configuration parameters.

 The electric field (G4UniformElectricField) is then created in 
 F02DetectorConstruction::ConstructSDanField() and passed to
 G4FieldBuilder, that constructs all necessary objects according
 to the user defined (or default) configuration parameters.

\section field02_s1 GEOMETRY DEFINITION

 The "Absorber" is a solid made of a given material.

 Three parameters define the absorber :
 - the material of the absorber,
 - the thickness of an absorber,
 - the transverse size of the absorber (the input face is a square).

 The volume "World" contains the "Absorber".
 In this test the parameters of the "World" can be changed , too.

 In addition a transverse uniform electric field can be applied.

 The default geometry is constructed in F02DetectorConstruction class,
 but all the parameters can be changed via
 the commands defined in the F02DetectorMessenger class.

\section field02_s2 AN EVENT : THE PRIMARY GENERATOR

 The primary kinematic consists of a single particle which hits the
 absorber perpendicular to the input face. The type of the particle
 and its energy are set in the F02PrimaryGeneratorAction class, and can
 be changed via the G4 build-in commands of G4ParticleGun class (see
 the macros provided with this example).

 It is also possible to change the position of the primary particle vertex
 or activate its randomization via the commands defined in  the
 F01PrimaryGeneratorMessenger class.

 A RUN is a set of events.

\section field02_s3 DETECTOR RESPONSE


 A HIT is a record, event per event , of all the
 informations needed to simulate and analyse the detector response.

 In this example a F02CalorHit is defined as a set of 2 informations:
 - the total energy deposit in the absorber,
 - the total tracklength of all charged particles in the absorber,

 Therefore  the absorber is declared
 'sensitive detector' (SD), see F02CalorimeterSD, which means they can contribute to the hit.

\section field02_s4 PHYSICS LIST

 The particle's type and the physic processes which will be available
 in this example are set in the FTFP_BERT physics list. This physics list
 requires data files for electromagnetic and hadronic processes.
 See more on installation of the datasets in Geant4 Installation Guide,

\section field02_s5 HOW TO START ?

 - Execute field02 in 'batch' mode from macro file e.g.
\verbatim
% ./field02 field02.in
\endverbatim

 - Execute field02 in 'interactive' mode with visualization e.g.
\verbatim
% ./field02
....
Idle> /run/beamOn 1
....
\endverbatim
*/
