This may be what enables compact high energy gamma ray sources. One example application is scanning cargo containers etc for hidden fissionable material by caus

This may be what enables compact high energy gamma ray sources. One example application is scanning cargo containers etc for hidden fissionable material by causing photofission and detecting the neutrons. Very few things emit lots of neutrons when hit with gamma rays below 10 MeV that aren't proliferation related. Gamma rays also don't really activate materials, so scanning something in this way doesn't create radioactive material.