Photonuclear activation of ground

[snorkack]

Which energy gamma rays would significantly activate ground and buildings?

The most sensitive stable isotopes for photonuclear reactions are Be-9 and D. The reactions are
Be-9+hnu->2*alpha+n, threshold 1,67 MeV, followed in air by
N-14+n->C-14+p
where C-14 is radioactive, and
d+hnu->p+n, threshold 2,23 MeV, followed by same C-14 in air.
Dry air has lowest photonuclear reaction
N-14+hnu->N-13+n, threshold 10,5 MeV, where N-13 is radioactive and n likewise produces C-14
O-16 has activation threshold 16,6 MeV
So how about irradiation of ground? Between the common isotopes of common elements in ground and buildings
Si, O, Al, Mg, Ca, Fe
which have lowest threshold for photonuclear reactions whereby radioactive isotopes are produced?

 

[Ibrahim Hany]

I did not encounter such search before, but I think a way to approach the answer is: plotting the photon-reaction cross-sections of common isotopes found in ground* and noticing what are the most probable reactions to take place. By that, you will have the isotopes that have highest probability of activation and you will get the energy of the photon that would cause such activation.

*https://www-nds.iaea.org/