Modular Physics Lists¶
The default list we provide is a Modular physics list. It is specified by the parameters described here.
The Geant4 EM physics group recommends against setting EMRangeMin
too low:
- Set to 100. eV or greater when using standard Geant4 EM physics
- Set to 10. eV or greater when using Geant4-DNA physics
If you want to run with no physics, but only the transportation process (useful for some demos and tests), specify the modules in the following special way:
sv:Ph/Default/Modules = 1 "Transportation_Only"
If you want to simplify physics so that only basic electromagnetic physics is done (useful for making basic geometry tests run faster), specify just the one module:
sv:Ph/Default/Modules = 1 “g4em-standard_opt0”
Below is a List of Available Modules with the corresponding Geant4 class names. Users who are advanced experts in Geant4 physics can also write their own Geant4 physics modules.
The remaining options for the "Geant4_Modular"
physics type are:
d:Ph/Default/CutForAllParticles = 0.05 mm # single range cut to use for all particles
d:Ph/Default/CutForGamma = 0.05 mm # overrides CutForAllParticles for Gamma
d:Ph/Default/CutForElectron = 0.05 mm # overrides CutForAllParticles for Electron
d:Ph/Default/CutForPositron = 0.05 mm # overrides CutForAllParticles for Positron
d:Ph/Default/CutForProton = 0.05 mm # overrides CutForAllParticles for Proton
d:Ph/Default/CutForAlpha = 0.05 mm # overrides CutForAllParticles for Alpha
d:Ph/Default/CutForDeuteron = 0.05 mm # overrides CutForAllParticles for Deuteron
d:Ph/Default/CutForTriton = 0.05 mm # overrides CutForAllParticles for Triton
d:Ph/Default/EMRangeMin = 100. eV # minimum for EM tables
d:Ph/Default/EMRangeMax = 500. MeV # maximum for EM tables
i:Ph/Default/EMBins = 77 # number of bins for EM tables
i:Ph/Default/EMBinsPerDecade = 7 # number of bins per decade for EM tables
b:Ph/Default/Fluorescence = "False" # Set to true to turn on Fluorescence
b:Ph/Default/Auger = "False" # Set to true to turn on Auger
b:Ph/Default/AugerCascade = "False" # Set to true to turn on AugerCascade
b:Ph/Default/DeexcitationIgnoreCut = "False" # Set to true to implement DeexcitationIgnoreCut
b:Ph/Default/PIXE = "False" # Set to true to turn on PIXE
Physics Regions¶
By default, cuts affect the entire world, but you can optionally divide the world into several regions and can specify different cuts in each region. First, specify which components belong to a given region:
s:Ge/MyComponent/AssignToRegionNamed = "MyRegion"
- All children of this component will also be assigned to that region, unless the child has its own
AssignToRegionNamed
parameter. - There is no requirement that all of the components in a given region be contiguous.
Then assign cuts per region by including the region name in the parameter name as in:
d:Ph/Default/ForRegion/MyRegion/CutForGamma = 0.05 mm
d:Ph/Default/ForRegion/MyRegion/CutForElectron = 0.05 mm
d:Ph/Default/ForRegion/MyRegion/CutForPositron = 0.05 mm
d:Ph/Default/ForRegion/MyRegion/CutForProton = 0.05 mm
Note: CutForAllParticles
does not have effect on physics regions. The cuts in physics regions should be specifically assigned to each particle. On the contrary, a cut of 0.05 mm will be assigned for the particles without specified cuts in the named region.
Cuts do not affect all processes, but only those listed below:
Energy thresholds for gamma are used in Bremsstrahlung
Energy thresholds for electrons are used in ionization and e+e- pair production processes Energy thresholds for positrons are used in e+e- pair production process
Energy thresholds for gamma and electrons are used optionally in all discrete processes
- Photoelectriceffect
- Compton
- gamma conversion
Energy thresholds for protons are used in processes of elastic scattering for hadrons and ions defining the threshold for kinetic energy of nuclear recoil
List of Available Modules¶
Users who are advanced experts in Geant4 physics can also write their own Geant4 physics modules and plug these into TOPAS through the Extensions Interface.
TOPAS Module Name | Geant4 Class Name |
---|---|
g4h-chargeexchange | G4ChargeExchangePhysics |
g4decay | G4DecayPhysics |
g4em-dna | G4EmDNAPhysics |
g4em-dna_opt1 | G4EmDNAPhysics_option1 |
g4em-dna_opt2 | G4EmDNAPhysics_option2 |
g4em-dna_opt3 | G4EmDNAPhysics_option3 |
g4em-dna_opt4 | G4EmDNAPhysics_option4 |
g4em-dna_opt5 | G4EmDNAPhysics_option5 |
g4em-dna_opt6 | G4EmDNAPhysics_option6 |
g4em-dna_opt7 | G4EmDNAPhysics_option7 |
g4em-dna_opt8 | G4EmDNAPhysics_option8 |
g4em-dna-stationary | G4EmDNAPhysics_stationary |
g4em-dna-stationary_opt2 | G4EmDNAPhysics_stationary_option2 |
g4em-dna-stationary_opt4 | G4EmDNAPhysics_stationary_option4 |
g4em-dna-stationary_opt6 | G4EmDNAPhysics_stationary_option6 |
g4em-dna-chemistry | G4EmDNAChemistry |
g4em-standard_GS | G4EmStandardPhysicsGS |
g4em-standard_SS | G4EmStandardPhysicsSS |
g4em-standard_WVI | G4EmStandardPhysicsWVI |
g4h-phy_QGSP_BIC_AllHP | G4HadronPhysicsQGSP_BIC_AllHP |
g4em-extra | G4EmExtraPhysics |
g4em-livermore | G4EmLivermorePhysics |
g4em-polarized | G4EmLivermorePolarizedPhysics |
g4em-lowep | G4EmLowEPPhysics |
g4em-penelope | G4EmPenelopePhysics |
g4em-standard_opt0 | G4EmStandardPhysics |
g4em-standard_opt1 | G4EMStandardPhysics_option1 |
g4em-standard_opt2 | G4EMStandardPhysics_option2 |
g4em-standard_opt3 | G4EMStandardPhysics_option3 |
g4em-standard_opt4 | G4EMStandardPhysics_option4 |
g4h-elastic_D | G4HadronDElasticPhysics |
g4h-elastic | G4HadronElasticPhysics |
g4h-elastic_HP | G4HadronElasticPhysicsHP |
g4h-elastic_LEND | G4HadronElasticPhysicsLEND |
g4h-elastic_XS | G4HadronElasticPhysicsXS |
g4h-elastic_H | G4HadronHElasticPhysics |
g4h-inelastic_QBBC | G4HadronInelasticQBBC |
g4h-phy_FTFP_BERT | HadronPhysicsFTFP_BERT |
g4h-phy_FTFP_BERT_HP | HadronPhysicsFTFP_BERT_HP |
g4h-phy_FTFP_BERT_TRV | HadronPhysicsFTFP_BERT_TRV |
g4h-phy_FTF_BIC | HadronPhysicsFTF_BIC |
g4h-phy_QGSP_BERT | HadronPhysicsQGSP_BERT |
g4h-phy_QGSP_BERT_HP | HadronPhysicsQGSP_BERT_HP |
g4h-phy_QGSP_BIC | HadronPhysicsQGSP_BIC |
g4h-phy_QGSP_BIC_HP | HadronPhysicsQGSP_BIC_HP |
g4h-phy_QGSP_FTFP_BERT | HadronPhysicsQGSP_FTFP_BERT |
g4h-phy_QGS_BIC | HadronPhysicsQGS_BIC |
g4h-phy_Shielding | HadronPhysicsShielding |
g4ion-binarycascade | G4IonBinaryCascadePhysics |
g4ion-inclxx | G4IonINCLXXPhysics |
g4ion | G4IonPhysics |
g4ion-QMD | G4IonQMDPhysics |
g4n-trackingcut | G4NeutronTrackingCut |
g4optical | G4OpticalPhysics |
g4radioactivedecay | G4RadioactiveDecayPhysics |
g4stopping | G4StoppingPhysics |