Concept and Design Studies for the Exploration of High Energy Gamma Ray Astronomy on the Gamma Ray Observatory.

The EGRET high energy gamma-ray telescope is one of four instruments to be included on the Gamma Ray Observatory mission, a Shuttle-launched free-flying satellite scheduled for launch in the late 1980's. This instrument, a spark chamber telescope with a NaI(Tl) crystal energy spectrometer, will cover the energy range from 12 MeV to 24,000 MeV, with much better sensitivity and spectral and spatial resolution than any previous experiment in this energy range. The design and performance of the EGRET instrument, with particular reference to those components that are the responsibility of Stanford University are described.