Terry, Aha ... imaginary weapons. Now I see why your are curious. It is hard to believe Collins missed Scandium, except that he had a mind-set for a laser gamma and not a gamma chain reaction.
As I recall, Scandium 'induced emission' is one of the greatest anomalies for a natural element in the periodic table. It is similar to the Fe-57 Mossbauer emission or the iridium - in a way. Were it a coherent emission, like the Mossbauer, which it is not, the military would have tried to embargo the world supply. Not they they haven't tried to anyway. There should be an non-military energy use for it but nowadays only a few labs have access. Jones

