Recovery of particles created inside a volume (not entering) : phase space?

Dear Geant4 users,

It may be an obvious question : does the Phase Space Actor with command line

/gate/actor/MyActor/storeSecondaries true

stores only secondary particles created in the volume the actor is attached to or secondary particle created in the volume + secondary particle entering the volume ?

I would like to retrieve only the photo-electrons created in the volume (not the ones entering the volume). Is it possible with a Phase Space or should I maybe use the SecondaryProductionActor ?

Thank you for your help,

Sarah Blind

Geant4 Version: 11.1.0
Operating System: Ubuntu 20.04.6 LTS
Compiler/Version: 9.4.0
CMake Version: 3.16.3

From the command name, this looks like it’s running GATE? If so, it’s probably better to address the question to the GATE support mailing list.

Certainly, it’s possible to record only secondaries created in a specific volume in Geant4, but GATE will have its own tools/methods to support/enable that.

Dear bmorgan,

Thank you very much for your response.

Yes, I use the Phase Space actor through GATE. But I could not obtain any help with the GATE support mailing list, so I though I would try to ask my question here since the Phase Space actor is also used with Geant4, isn’t ?


From a cursory look at the GATE code, I think the SecondaryProductionActor is more suitable for what you want to record. However, it’s not clear to me that distinguishes the creator process of the secondary electrons as anything other than “by ionisation” “not by ionisation”. Similarly, in the PhaseSpaceActor, I can’t work out what info it stores on secondaries (i.e. if it tells you the creator process).

“Actors” are a GATE concept as far as I can tell, though fundamentally built on top of the core Geant4 concepts of Actions on Begin/End/With Run/Event/Track/Step.