Definition of ion source

Dear all,
How to simulate the decay of y-90 radioisotope as a source of primary particles, taking into account all decays and all its energies in calculating the final dose?

If you are using Geant4, then → Geant4 User Forum

Hello,
Thank you for your help, if it is possible, please give some help here. I still haven’t managed to create a topic in the Geant4 forum.