Hi David,
Thank you for your patience ! We have identified the bug leading to the doubling of the gammas in the case of the Cd109 decay. The underlying reason is that FLUKA treats a decay in multiple steps, stopping at intermediate points in the decay chain, emitting products for each step at a time. In this case, the isomeric state 109Ag* is sufficiently long-lived to be considered a stopping point. The decay is thus performed as such in FLUKA
- 109Cd → 109Ag* (EC) then
- 109Ag* → 109Ag (IT)
However, our decay radiation database comes from ENSDF. In ENSDF, 109Cd → 109 Ag is considered one decay which contains both decay products from the EC and the IT. When performing the two steps indicated above, we produce gammas (and CE) corresponding to the deexcitation of Ag twice
We have implemented a patch to the decay database removing 109Ag* decay products from the 109Cd, which will be live in the next minor release.
Kind regards