Lessons learnt from COMPTEL for future telescopes

Abstract After COMPTEL on NASA’s Compton γ-ray observatory has opened the 1–30 MeV range as a new window to astronomy, large world-wide efforts are now being undertaken to develop the next generation of Compton telescopes. The history of the Compton telescope development is reviewed and general guidelines for the design of new instruments are given with special emphasize to maximising the detection efficiency and minimising instrumental background radiation.