Physics Lists EM constructors in Geant4 9.3

Default

• emstandard The default EM constructor G4EmStandardPhysics.cc is used in major part of reference Phsycs Lists (QGSP_BERT, QGSP_BIC, FTF_BIC, FTFP_BERT, ...).

Option 1

• emstandard_opt1 is designed for HEP productions, it is used in the QGSP_BERT_EMV reference Physics List. The corresponding physics constructor G4EmStandardPhysics_option1.cc includes following modifications for electron and positron transport with respect to the default EM physics:
  • the option "fMinimal" is used for multiple scattering step limitation, which provides accuracy and CPU performance similar to that of the Geant4 version 7.1p02;
  • the parameter dRoverRange used in computation of step limit by the ionisation process is set to the value 0.8.
  • the ApplyCuts option is enabling production thresholds (cuts) on secondary particles for all EM processes including photoelectric effect, Compton scattering, gamma conversion, positron annihilation.

Option 2

• emstandard_opt2 designed for HEP applications, it is used in the QGSP_EMX reference Physics List. The corresponding physics constructor G4EmStandardPhysics_option2.cc includes following modifications with respect to the default EM physics:
  • the option "ApplyCuts" is used enabling kill of electrons and gammas produced below production thresholds for all EM processes;
  • specialized process for muon multiple scattering is used, this process takes into account small angle scattering (below 0.2 rad), for large scattering angles the single scattering process is used.

Option 3

• emstandard_opt3 designed for any applications required higher accuracy of electrons, hadrons and ion tracking without magnetic field. It is used in extended electromagnetic examples. The corresponding physics constructor G4EmStandardPhysics_option3.cc includes following modifications:
  • the option "fUseDistanceToBoundary" for multiple scattering of electrons and positrons;
  • increased number of bins in physics tables - 220 (84 bins by default);
  • the parameter finalRange used in computation of step limit by the ionisation process is reduced with respect to the default value 1 mm: for e+,e- is 0.1 mm, for muons, pions, proton is 0.05 mm, for ions 0.02 mm.

Livermore

• emlivermore designed for any applications required higher accuracy of electrons, hadrons and ion tracking without magnetic field. It is used in extended electromagnetic examples. The corresponding physics constructor G4EmLivermorePhysics.cc includes following modifications:
  • the option "fUseDistanceToBoundary" for multiple scattering of electrons and positrons;
  • increased number of bins in physics tables - 220 (84 bins by default);
  • the parameter finalRange used in computation of step limit by the ionisation process is reduced with respect to the default value 1 mm: for e+,e- is 0.1 mm, for muons, pions, proton is 0.05 mm, for ions 0.02 mm.

Livermore with polarisation

• emlivermore_polar designed for any applications required higher accuracy of electrons, hadrons and ion tracking without magnetic field. It is used in extended electromagnetic examples. The corresponding physics constructor G4EmLivermorePolarizedPhysics.cc includes following modifications:
  • the option "fUseDistanceToBoundary" for multiple scattering of electrons and positrons;
  • increased number of bins in physics tables - 220 (84 bins by default);
  • the parameter finalRange used in computation of step limit by the ionisation process is reduced with respect to the default value 1 mm: for e+,e- is 0.1 mm, for muons, pions, proton is 0.05 mm, for ions 0.02 mm.

Penelope

• empenelope designed for any applications required higher accuracy of electrons, hadrons and ion tracking without magnetic field. It is used in extended electromagnetic examples. The corresponding physics constructor G4EmPenelopePhysics.cc includes following modifications:
  • the option "fUseDistanceToBoundary" for multiple scattering of electrons and positrons;
  • increased number of bins in physics tables - 220 (84 bins by default);
  • the parameter finalRange used in computation of step limit by the ionisation process is reduced with respect to the default value 1 mm: for e+,e- is 0.1 mm, for muons, pions, proton is 0.05 mm, for ions 0.02 mm.

DNA physics

Physics Lists of Geant4 examples