Annihilation

Models

class EPlusGGInteractor

Annihilate a positron to create two gammas.

This is a model for the discrete positron-electron annihilation process which simulates the in-flight annihilation of a positron with an atomic electron and produces into two photons. It is assumed that the atomic electron is initially free and at rest.

Note

This performs the same sampling routine as in Geant4’s G4eeToTwoGammaModel class, as documented in section 10.3 of the Geant4 Physics Reference (release 10.6). The maximum energy for the model is specified in Geant4.

Cross sections

Positron annihilation cross sections are calculated on the fly.

class EPlusGGMacroXsCalculator

Calculates the macroscopic cross section of positron annihilation.

The Heitler formula (section 10.3.2 of the Geant4 Physics Reference Manual, Release 10.6) is used to compute the macroscopic cross section for positron annihilation on the fly at the given energy.