(telescope that detects gamma rays via pair production)
The term pair telescope refers to a gamma-raytelescope
designed to detect high-energyphotons by detecting
the pair production they produce within its scintillator.
Such photons have an energy of at least 1 MeV but practically
speaking, 30 MeV is the photon energy at which pair production
predominates. Fermi (aka GLAST) uses this concept.