How to apply DNA chemistry to particular region?


Could you please help me. I need to use a combination of DNA physics + DNA chemistry in one region while using standard physics in another region. Similar thing is done in “dnaphysics” example with “G4EmDNAPhysicsActivator”, but it only covers DNA physics (not DNA chemistry). It is also done in “microdosimetry” example, but it also doesn’t use chemistry at all. In the end both “G4EmDNAPhysicsActivator” and “microdosimetry” use G4EmConfigurator class and SetExtraEmMode function to apply different models to different regions, but I’m not sure how can I do this with chemistry. Is it even possible?


A general comment: when DNA physics is defined per region the initial state for chemistry should be created inside this articular region. So, chemistry may be defined for everything but in reality will work only in the region where initial state for chemistry will be prepared.

If this general schema does not work let us follow one of existing Geant4 extended dna example. Please, demonstrate the problem within such example.


Thank you for the comment. But how to create initial state for chemistry for a particular region ignoring the rest? For example, to make one region use DNA physics without chemistry while another would use DNA physics with chemistry? Is there a simple way to do that or one need to copy all the content of G4EmDNAChemistry into his PhysicsList and disable each DNA chemistry model one by one?

Hi there,
Please see the example “dnadamage” in version 10.6. Maybe, it can anwser some questions.