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

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 F02ElectricFieldSetup. Its object is created in the ConstructSDandField() function in the F02DetectorConstruction class. The interactive commands are implemented in F02FieldMessenger.

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.

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.

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.

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,

HOW TO START ?

Execute field02 in 'batch' mode from macro file e.g.
```
% ./field02 field02.in
```
Execute field02 in 'interactive' mode with visualization e.g.
```
% ./field02
....
Idle> /run/beamOn 1
....
```