Summary

The implemented physics models are meant to match the defaults constructed in G4EmStandardPhysics. Known differences are:

  • Particles other than electrons, positrons, and gammas are not currently supported.

  • As with the AdePT project, Celeritas currently extends the range of Urban MSC to higher energies rather than implementing the Wentzel-VI and discrete Coulomb scattering.

  • Celeritas imports tracking cutoffs and other parameters from G4EmParameters, but some custom model cutoffs are not accessible to Celeritas.

The following table summarizes the EM processes and models in Celeritas.

Electromagnetic physics processes and models available in Celeritas.

Particle

Processes

Models

Celeritas Implementation

Applicability

\(e^-\)

Ionization

Møller

celeritas::MollerBhabhaInteractor

0–100 TeV

Bremsstrahlung

Seltzer–Berger

celeritas::SeltzerBergerInteractor

0–1 GeV

Relativistic

celeritas::RelativisticBremInteractor

1 GeV – 100 TeV

Coulomb scattering

Urban

celeritas::UrbanMscScatter

100 eV – 100 TeV

Coulomb

celeritas::CoulombScatteringInteractor

0–100 TeV

\(e^+\)

Ionization

Bhabha

celeritas::MollerBhabhaInteractor

0–100 TeV

Bremsstrahlung

Seltzer-Berger

celeritas::SeltzerBergerInteractor

0–1 GeV

Relativistic

celeritas::RelativisticBremInteractor

1 GeV – 100 TeV

Coulomb scattering

Urban

celeritas::UrbanMscScatter

100 eV – 100 TeV

Coulomb

celeritas::CoulombScatteringInteractor

0–100 TeV

Annihilation

\(e^+,e^- \to 2\gamma\)

celeritas::EPlusGGInteractor

0–100 TeV

\(\gamma\)

Photoelectric

Livermore

celeritas::LivermorePEInteractor

0–100 TeV

Compton scattering

Klein–Nishina

celeritas::KleinNishinaInteractor

0–100 TeV

Pair production

Bethe–Heitler

celeritas::BetheHeitlerInteractor

0–100 TeV

Rayleigh scattering

Livermore

celeritas::RayleighInteractor

0–100 TeV

\(\mu^-\)

Ionization

ICRU73QO

celeritas::MuHadIonizationInteractor

0–200 keV

Bethe–Bloch

celeritas::MuHadIonizationInteractor

200 keV–1 GeV

Mu Bethe–Bloch

celeritas::MuHadIonizationInteractor

200 keV–100 TeV

Bremsstrahlung

Mu bremsstrahlung

celeritas::MuBremsstrahlungInteractor

0–100 TeV

Pair production

Mu pair production

celeritas::MuPairProductionInteractor

0.85 GeV–100 TeV

\(\mu^+\)

Ionization

Bragg

celeritas::MuHadIonizationInteractor

0–200 keV

Bethe–Bloch

celeritas::MuHadIonizationInteractor

200 keV–1 GeV

Mu Bethe–Bloch

celeritas::MuHadIonizationInteractor

200 keV–100 TeV

Bremsstrahlung

Mu bremsstrahlung

celeritas::MuBremsstrahlungInteractor

0–100 TeV

Pair production

Mu pair production

celeritas::MuPairProductionInteractor

0.85 GeV–100 TeV