KNOWN BUGS
Comments By default, diffraction has been switched off for Fritoff models in 10.7 https://geant4-userdoc.web.cern.ch/UsersGuides/ForToolkitDeveloper/html/GuideToExtendFunctionality/HadronicPhysics/hadronics.html?highlight=default%20diffraction
Logs
The UI commands for Radioactive Decay are named /process/had/rdm/... The old commands /grdm/... are still valid, but deprecated, and will be removed in the next major release, Geant4.11.**
To enable building of ParticleHP as HP, use the new CMake option -GEANT4_BUILD_PHP_AS_HP=ON when building Geant4. The old environment variable PHP_AS_HP is still valid, but deprecated, and will be removed in the next major release. Geant4Config.cmake/geant4-config
G4TENDL-1.3.2 is the recommended version. version 1.4 also exists but has not been validated, although this can also be used if desired.
Added two extra sets of StepFunction parameters for light ions and generic ions. Added corresponding UI commands allowing one to customise step limitation for ions separately from step limits for electrons or hadrons.
New class for handling the numerical Differential Cross-Sections(DCS) for Coulomb scattering of e-/e+, and added new model, implementing single Coulomb scattering for e-/e+.
Added new threshold for muon/hadron bremsstrahlung and e+e- pair production allowing to stop a track when energy transfer exceeds the defined threshold and makes a new vertex.
For the evaluation of systematic errors due to uncertainties in the Geant4 hadronic cross sections we recommend to scale up and down the cross sections, independently for elastic and inelastic interactions, and independently for different types of hadrons. Currently, this is possible for the following three categories of hadrons: nucleons (i.e. proton and neutron together), pions (i.e. pion+ and pion- together), all the rest of hadrons (i.e. kaons, hyperons, anti-baryons, light ions, light anti-ions, charm and bottom hadrons all together). New public methods of the singleton class G4HadronicParameters allow to enable the scaling of these cross sections (disabled by default), and to set the scaling factors (by default 1.0). Here are some rough, practical suggestions on the scaling of the cross sections: +/- 10% variation for nucleons and pions; +/- 15-20% variation for kaons; +/- 20-30% variation for other hadrons. Moreover, bigger variations might be considered at low energies to account for the challenge of describing the shapes of cross sections in the threshold and resonance region.
Improved treatment of antibaryon interactions in QGS.
Enabled charm and bottom hadronic physics in nearly all physics lists, in particular those of inteHadronrest for HEP. (The main exceptions are the following physics lists: QGSP_BIC, QGSP_BIC_HP, QGSP_BIC_AllHP.) The QGS-based physics lists use, as for other hadrons, QGSP for charm and bottom inelastic interactions above 12 GeV, whereas FTFP is used below 25 GeV. The other, FTF-based physics lists, use FTFP at all energies, with a simplified approach below 100 MeV.
Physics lists that include G4EmExtraPhysics use the new low-energy gamma-nuclear model ( G4LowEGammaNuclearModel ) below 200 MeV (while Bertini cascade is used above 199 MeV up to 6 GeV, and QGSP above 3 GeV). The use of this model, its energy threshold and the alternative cross section G4GammaNuclearXS can be configured.
Expected slightly faster computation of hadronic cross-sections
Removed obsolete G4MuElec * classes.
G4MuPairProductionModel : optimised ComputeDMiscroscopicCrossSection() to speedup initialization.
Look at Geant4.10.4 log below.
G4MuPairProductionModel , G4MuBremmstrahlungModel , G4MuPairProduction , G4MuBremmstrahlung : updated sampling of final state using G4ModifiedMephi ; implemented check on energy transfer and if beyond the threshold, kill primary particle and create a new vertex.
G4ModifiedMephi : new angular generator for muon/hadron Bremsstrahlung.
G4UrbanMscModel : tuned tlimitmin computation for e- (for e+ kept unchanged) and changed parametrisation of stepmin; added two private inline methods to reduce code duplication. Removed cache and introduced data struct precomputed at initialisation, added e- range cut to the data structure. Changed parametrisation of backscattering parameter doverra ; Changed computation of tlimit in the step limitation algorithm UseDistanceToBoundary() ; affecting only Opt3 EM physics.
G4EmParameters , G4EmParametersMessenger , G4VMultipleScattering : removed displacement-beyond-safety option, as may lead to crashes in some circumstances, and wrong results in others.
Updated values in SystemOfUnits.h and PhysicalConstants.h for: e_SI (electron charge), h_Planck (Planck constant), Avogadro (Avogadro constant), k_Boltzmann (Boltzmann constant), based on May 2019 redefinition of SI units,
G4QGSPAntiBarionBuilder : created new class to handle anti_proton and anti_neutron at high energies with QGSP. For the light anti-ions (anti_deuteron, anti_triton, anti_He3, and anti_alpha), currently QGSP cannot handle them, therefore FTFP is used.
G4EmStandardPhysics_option1 : switch to use new G4EmBuilder utility; fixed StepFunction definition.
G4EmStandardPhysics_option3 : switch to use new G4EmBuilder utility; use ICRU90 stopping power data for water and air.
G4EmStandardPhysics_option4: use ICRU90 data.
G4EmStandardPhysicsSS : use the new G4eDPWACoulombScatteringModel for e-/e+ below 100 [MeV] (for testing this new model).
G4EmExtraPhysics : extension to anti_nu_mu, nu_e and anti_nu_e processes-models.
P02: G4EmStandardPhysics default verbosity set to 1. Has no effect on MC of course but may created unexpected outputs if log files are desired.
G4$HadronPhysicsQGSP_BIC_HP , G4HadronPhysicsQGSP_BIC_AllHP : refactoring consistently with all others. For G4HadronPhysicsQGSP_BIC_HP , the physics remains unchanged; for G4HadronPhysicsQGSP_BIC_AllHP , the physics remains unchanged except for the transition region between Binary and ProtonHP which is now 190-200 MeV (instead than 199-200), as for light ions.
P02: /gps/ang/maxphi is correctly set to 2pi (was 1pi*). Only affects users who make their own macros using gps
P02: Muon energy loss extrapolator fixed
P02: Excitation energies fixed for inelastic neutrons
P02: G4RadioactiveDecayBase: set the weight of secondaries tracks to the mother's weight value in the method `G4RadioactiveDecayBase::DecayAnalog()`. This bug, present since a long time, affects only simulations that use `Radioactive Decay` in analogue mode with "external" biasing (e.g. generic biasing, GPS generator with weights, etc.).
P03: Bug fix in `G4ParticleHPLabAngularEnergy` (affects `particle_hp`)
P03: G4SampleResonance: bug-fix in the method `GetMinimumMass()` in the use case rare and light decay channels (e.g. e+ e-) are included for hadronic resonances.