Molecule as Primary Particle?

I want to see how far ionised deuterium molecules can penetrate into a material.

I’m assuming the way to do this is to make an ionised deuterium D2 ion as the primary particle.
Is it possible to make this kind of primary particle in Geant4? and if not what could be an alternate approach?
I’ve done a bit of looking and found nothing regarding this.

Thanks for any response.

I have no idea, so I am asking more to satisfy my own curiosity :slight_smile:

Do you know of any examples in the literature modelling these systems? The atomisation energy for this ion should be around 2-3 eV. At keV energies, including the electronic structure and bond breaking of the projectile in the model seems crucial. I know of atomistic simulations of these systems, but I don’t know if such beam is within Geant4’s scope.

I haven’t found anything in the scientific literature.
I’m just curious myself and to see if I could do it as an exercise for myself to learn more about G4.

I’m still very curious to know if there is a way to do this.

The easiest way to do a simple penetration depth study would be to define a custom G4ParticleDefinition for the deuterium molecule. There are examples of defining new particle types in the “exoticphysics” set of examples.

This will be sufficient if you do not need to deal with the complexities of molecular energy levels, and if you don’t need to consider dissociation. For the latter, you would also need to write a G4VDiscreteProcess subclass to take your D2 molecule, kill it, and produce two deuterons as output.

The Geant4 Toolkit Developers Guide should give you some guidance on the general issues involved.

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Thank you very much!