Monash University low-energy electromagnetic models


Describes the process of unpolarised photons Compton scattering off atomic bound electrons in the relativistic impulse approximation. The model was developed as an alterative to Compton scattering models developed from Ribberfors' Compton scattering framework (link), i.e. G4LivermoreComptonModel and G4PenelopeComptonModel, to improve the accuracy of Compton electron ejection direction algorithms below 5 MeV. G4LowEPComptonModel utilises a special-relativistic formalism and the conservation of energy and momentum to compute:

  • energy and angular distributions of Compton scattered photons off non-stationary atomic bound electrons,
  • and energy and ejected angular distributions of Compton electrons.

A version for polarized gammas is also available: G4LowEPPolarizedComptonModel.

How to use the model in Geant4 user physics lists

The model can be used as follows:

      G4PhysicsListHelper* ph = G4PhysicsListHelper::GetPhysicsListHelper();
      G4ComptonScattering* cs = new G4ComptonScattering;
      G4VEmModel* theLowEPComptonModel = new G4LowEPComptonModel();
      cs->AddEmModel(0, theLowEPComptonModel);
      ph->RegisterProcess(cs, particle);

Physics builders

G4LowEPComptonModel is added to the electromagnetic physics constructor "G4EmStandard_option4" constructed from the most accurate models from standard / low energy electromagnetic physics groups.

Availability and documentation

You may check the following publication: A low energy bound atomic electron Compton scattering model for Geant4, J. M. C. Brown et al., Nucl. Instrum. and Meth. B 338 (2014) 77-88 (link)

Address any additional queries to

Edit | Attach | Watch | Print version | History: r8 < r7 < r6 < r5 < r4 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r8 - 2015-12-04 - SebastienIncerti
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    Geant4 All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
or Ideas, requests, problems regarding TWiki? use Discourse or Send feedback