questions
A few things in this article don't make sense to me.
1. Thorium has no isomeric states so how could DoD use it for this?
2. How does pumping naturally occuring Ta with protons yield any quantity of Hf178? I don't see any decay mode that work. It seems to me you would yield much more Hf178 by bombarding naturally occuring Hf177 with neutrons.
Dave M