Physics Lists EM constructors in Geant4 9.2

Default

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

emstandard_opt1 is designed for HEP productions, it is used in the QGSP_BERT_EMV reference Physics List. The corresponding physics constructor (G4EmStandardPhysics_option1) 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.

emstandard_opt2 designed for HEP applications, it is used in the QGSP_EMX reference Physics List. The corresponding physics constructor (G4EmStandardPhysics_option2) 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.

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) 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.

TestEm7 extended/electromagnetic example providing several variants of EM physics, which are also used in other Geant4 applications. This example can be recommended as a starting point for user customized Physics List.

livermore The physics constructor (PhysListEmLivermore) with low-energy electromagnetic processes for gamma, e-, hadrons and ions based on Livermore data sets.

peneloper The physics constructor (PhysListEmPenelope) with low-energy electromagnetic processes for gamma, e-, hadrons and ions based on Penelope models.

standardSS The physics constructor (PhysListEmStandardSS) in which multiple scattering process is substituted by single scattering.

standardNR The physics constructor (PhysListEmStandardNR) in which multiple scattering processes for protons and ions are substituted by single scattering process.

standardICRU73 The physics constructor (PhysicsList) in which a model of ion ionisation based on ICRU'73 data is used.

Last updated: 08 Feb 2012