Comment Re:I don't think it's X-Rays (Score 1) 295
'X-rays' apparently covers a pretty broad range of energies. They're probably referring to 'hard' or 'high energy' x-rays.
(https://en.wikipedia.org/wiki/Hard_x-ray (3rd paragraph)
(https://en.wikipedia.org/wiki/High_energy_X-rays
(https://en.wikipedia.org/wiki/High_energy_X-rays