How to know what process should I use for a model

Physics Processes, Models and Cross Sections
1

Dear experts

I wonder how can I know what process I should use by G4EmConfigurator::SetExtraEmModel() for a certain model.
For example, PAI model I used for every ionization processes (eIoni, muIoni, hIoni, ionIoni), for PAIPhot should I use for the same process? Or should I add phot process for gammas?

_Geant4 Version:_4.10.06
_Operating System:_AlmaLinux 9.2
_Compiler/Version:_gcc11

1 Like
2

Any idea how to know about this?

3

pop this up again, any ideas? :thinking:

4

@sunsiyuanyuan

Your question is quite confusing.
Please redefine your question in a simpler and better way with aim, and goals.

VRS

5

The way you wrote your subject line is “backwards.” In Geant4, the process is often abstract. It defines a particular kind of scattering (Bremsstrahlung, neutron capture, beta decay, whatever).

For a given process, there might be one or many different models which do the concrete calculation of the kinematics involved in the process. Which model you use might depend on how accurate you need the calculation to be, whether you want the calculation to be theoretical vs. data-driven, which theorist you trust more, and so on.

So the question might be better posed, “How do I decide which model to use for a given process?” Is that what you had in mind? Or are you asking something different, like “How do I know for which processes a given model name is applicable?”