electromagnetic/TestEm8/README.md

0001 \page ExampleTestEm8 Example TestEm8
0002
0003  Example for investigation of ionisation in thin absorbers and gaseous
0004  detectors
0005
0006 ## GEOMETRY DEFINITION
0007
0008  The target is a cylinder made of a given material placed inside
0009  cylindrical container, which is placed inside the world volume.
0010
0011  Following parameters define the geometry:
0012  - the material of the target,
0013  - the thickness of the target,
0014  - the radius of the target,
0015  - the material of the container,
0016  - the thickness of the container,
0017  - the material of the world.
0018
0019  The list of materials used in gaseous detectors are built inside
0020  the DetectorConstruction class, also NIST materials are available.
0021  The default geometry is provided but all parameters can be changed via
0022  UI commands defined in the DetectorMessenger class, for example,
0023
0024 ```
0025 /testem/setGasMat      XeCH4C3H8
0026 /testem/setWindowMat   G4_MYLAR
0027 /testem/setWorldMat    G4_AIR
0028 /testem/setGasThick    10 cm
0029 /testem/setGasRad      20 cm
0030 /testem/setWindowThick 50 um
0031 ```
0032
0033 ## AN EVENT : THE PRIMARY GENERATOR
0034
0035   The primary kinematic consists of a single particle which hits the
0036   absorber perpendicular to the input face. The type of the particle
0037   and its energy can be set via the G4 build-in commands of G4ParticleGun .
0038   A RUN is a set of events.
0039
0040 ## DETECTOR RESPONSE
0041
0042   The TargetSD class sending information about each step inside the target
0043   to the HistoManager class scoring of energy deposition in the detector.
0044   Additionally at each step of a particle inside the target the number of
0045   ionisation clusters is sampled using G4ElectronIonPair helper class. The
0046   parameter of transformation of energy into ionisation clusters can be
0047   set via UI command:
0048
0049 ```
0050 /testem/setPairEnergy 19 eV
0051 ```
0052
0053 ## PHYSICS
0054
0055   The particle's type and the physics processes which will be available
0056   in this example are set in PhysicsList class, which uses Geant4
0057   EM physics constructors provided in the physics_list library.
0058
0059   The PhysicsListMessenger classes introduce interactive commands. In particular,
0060   PAI ionisation model can be added using G4EmConfigurator helper class,
0061   which is invoked by the UI command
0062
0063 ```
0064 /testem/phys/addPhysics pai
0065 /testem/phys/addPhysics pai_photon
0066 /process/em/AddPAIRegion all GasDetector pai
0067 /process/em/AddPAIRegion all GasDetector pai_photon
0068 ```
0069
0070   Cuts for all setup and/or for sensitive volume may changed via commands:
0071
0072 ```
0073 /run/setCut  0.5 mm
0074 /run/setCutForRegion GasDetector 1.8 mm
0075 ```
0076
0077 ## HOW TO START ?
0078
0079   - Execute TestEm8 in 'batch' mode from macro files e.g.
0080 ```
0081 % ./TestEm8  TestEm8.in N
0082 ```
0083     here N means number of threads in multi-threaded mode, by
0084     default 2 threads are used
0085
0086   - Execute TestEm8 in 'interactive' mode with visualization e.g.
0087 ```
0088 % ./TestEm8
0089 ....
0090 Idle> type your commands
0091 ....
0092 ```