The Bertini model generates the final state for hadron inelastic scattering by simulating the intra-nuclear cascade. This model is a re-engineered version of the INUCL code in which incident hadrons collide with protons and neutrons in the target nucleus and produce secondaries which in turn collide with other nucleons. The final state of each collision is sampled according to free-particle cross section data. The target nucleus is treated as an average nuclear medium to which excitons (particle-hole states) are added after each collision. At the end of the cascade the excited nucleus is represented as a sum of particle-hole states which is then decayed by pre-equilibrium, nucleus explosion, fission and evaporation methods.
This model reproduces detailed cross section data for nucleons, pions and kaons in the region below 1 GeV and is expected to do reasonably well in the multi-GeV region. An alternative model, the Binary cascade, also does well for protons, neutrons and pions in the same energy region.
For details of this model, see the chapter on the Bertini Cascade Model in the Geant4 Physics Reference Manual.
G4CascadeInterface* bertiniModel = new G4CascadeInterface();
G4ProtonInelasticProcess* inelProcess = new G4ProtonInelasticProcess(); inelProcess->RegisterMe(bertiniModel); processManager->AddDiscreteProcess(inelProcess);