Energetic Gamma Ray Experiment 中国斜学我术大学 Telescope(EGRET) University of Science and Technology of China Gamma .Ray Plastic Upper Spark pair telescope Scintillator Chamber Assembly 0.75-30MeV e Tracker:spark chamber Lower .Spark Chamber Calorimeter:Nal crystal Assembly Crystal Scintillator Photomultipliers- Particles absorbed:" light emittedEnergetic Gamma Ray Experiment Telescope(EGRET) pair telescope 0.75 - 30 MeV Tracker: spark chamber Calorimeter: NaI crystal