Ground-based VHE gamma ray astronomy with air Cherenkov imaging telescopes

The history of astronomy has been one of the scientific discovery following immediately the introduction of new technology. In this report, we will re view shortly the basic development of the atmospheric air Cherenkov light d etection technique, particularly the imaging telescope technique, which in the last years led to the firm establishment of a new branch in experimenta l astronomy, namely ground-based very high-energy (VHE) gamma ray astronomy . Milestones in the technology and in the analysis of imaging technique wil l be discussed. The design of the 17 m circle divide MAGIC Telescope, being currently under construction, is based on the development of new technolog ies for all its major parts and sets new standards in the performance of th e ground-based gamma detectors. MAGIC is one of the next major steps in the development of the technique being the first instrument that will allow on e to carry out measurements also in the not yet investigated energy gap i.e . between 10 and 300 GeV. (C) 2000 Elsevier Science B.V. All rights reserve d.