field/field03/README.md

0001 \page Examplefield03 Example  field03
0002
0003  Example of tracking in magnetic field where field associated
0004  to selected logical volumes varies.
0005
0006  A global and a local magnetic field are defined in
0007  the  F03DetectorConstruction::ConstructSDandField() method in the
0008  F03DetectorConstruction class using the G4FieldBuilder class.
0009  The local magnetic field is set to the "Radiator" volume.
0010
0011  The interactive commands, under the /field directory, are created with
0012  the instantiation of G4FieldBuilder in the F03DetectorConstruction constructor,
0013
0014 ## GEOMETRY DEFINITION
0015
0016  The "Absorber" is a solid made of a given material.
0017
0018  Three parameters define the absorber :
0019  - the material of the absorber,
0020         - the thickness of an absorber,
0021  - the transverse size of the absorber (the input face is a square).
0022
0023  The volume "World" contains the "Absorber".
0024  In this test the parameters of the "World" can be changed , too.
0025
0026  A transverse global uniform magnetic field can be applied.
0027  In addition, the "Radiator" volume, which is placed in geometry next
0028  to the absorber, has a local magnetic field.
0029
0030  The default geometry is constructed in F03DetectorConstruction class,
0031  but all the parameters can be changed via
0032  the commands defined in the F03DetectorMessenger class.
0033
0034 ## AN EVENT : THE PRIMARY GENERATOR
0035
0036  The primary kinematic consists of a single particle which hits the
0037  absorber perpendicular to the input face. The type of the particle
0038  and its energy are set in the F03PrimaryGeneratorAction class, and can
0039  be changed via the G4 build-in commands of G4ParticleGun class (see
0040  the macros provided with this example).
0041
0042  It is also possible to change the position of the primary particle vertex
0043  or activate its randomization via the commands defined in  the
0044  F01PrimaryGeneratorMessenger class.
0045
0046  A RUN is a set of events.
0047
0048 ## DETECTOR RESPONSE
0049
0050
0051  A HIT is a record, event per event , of all the
0052  informations needed to simulate and analyse the detector response.
0053
0054  In this example a F03CalorHit is defined as a set of 2 informations:
0055  - the total energy deposit in the absorber,
0056  - the total tracklength of all charged particles in the absorber,
0057
0058  Therefore  the absorber is declared
0059  'sensitive detector' (SD), see F03CalorimeterSD, which means they can contribute to the hit.
0060
0061
0062 ### PHYSICS LIST
0063
0064  The particle's type and the physic processes which will be available
0065  in this example are set in the FTFP_BERT physics list. This physics list
0066  requires data files for electromagnetic and hadronic processes.
0067  See more on installation of the datasets in Geant4 Installation Guide,
0068
0069 ## HOW TO START ?
0070
0071  - Execute field03 in 'batch' mode from macro files e.g.
0072 ```
0073 % ./field03 field03.in
0074 ```
0075
0076  - Execute field03 in 'interactive' mode with visualization e.g.
0077 ```
0078 % ./field03
0079 ....
0080 Idle> /run/beamOn 1
0081 ....
0082 ```