Geat4-dna physics for Neutron

Hi,
I want to use /example/extended/microyz input for microdosimetry of 14 MeV neutron and 5 MeV alpha particles with Geant4-dna physics list.

Is it possible ?

If not, please advice some alternative.

The Geant4-DNA physics list models the EM interactions of charged particles. You can use it for 5 MeV alpha particles.

For incident neutrons, you have to model the nuclear interactions, therefore you should couple the Geant4 hadronic physics with Geant4-DNA, describing the interactions of secondary charged particles. You can try that, however I am not 100% sure Geant4-DNA can describe the EM interactions of all secondary fragments (it depends a lot on the composition of your target). Try. if it does not work, other solutions can be adopted. In my point of view, the easiest is to use Livermore physics models, using a cut of 10 eV.

Thank you very much for your suggestions.

One more query I will like to clear from you.

If I use Livermore physics (along with Geant4 hadronic physics), then I have to put some value of S_L (maximum step length) in the macrolist of “/example/extended/microyz”.

What should be the typical value of S_L I should put for 14 MeV neutron and site size of 1um or 1 nm.
Thanking you in advance.

I would start with 1/4 or 1/5 of the size of the sensitive volume. You can then try lower values of the S_L and see if you get the same results from the simulation. I think that the proposed approach with Livermore for 1 um sized SV should be , let’s say, ok based on the current status of Geant4, Geant4-DNA and MC codes in general. For a SV of 1 nm, I would not feel confident at all to use a Condensed History approach. In that case I suggest you use Geant4-DNA. Please look at the paper "Investigation of track structure and condensed history physics models " by Peter Lazarakis, Sebastien Incerti et al. .