Hi
When I did some simulations for photonuclear interactions with Ra-226 I could use directly radium as material in the simulation but I had to set a high neutron transport threshold. If I understand @ceruttif 's answer correctly, the low energy parametrization of the photonuclear cross section has not changed (and this paper is still the correct reference), right?
Or could the problem be related to the newly implemented electronuclear interactions? But I guess this effect would be irrelevant in a thin target simulation.
Cheers,
lorenzo