Design studies on large Cherenkov telescopes

Abstract

Presently the ground-based High Energy Stereoscopic System (H.E.S.S.) with 12 m Cherenkov telescopes is used for very high energy gamma ray astronomy. With these telescopes the Cherenkov light which is generated when cosmic gamma rays are absorbed by the atmosphere is collected by the mirror dishes of these optical telescopes and recorded by digital cameras for further examination. This existing H.E.S.S. Phase I system in Namibia erected and operated by the Max-Planck-Institut fur Kernphysik in Heidelberg, Germany, uses four 12 m telescopes arranged in the corners of a 120 m square for best sensitivity. The next step in order to increase the exploitation of the gamma rays in the atmosphere is to use bigger Cherenkov telescopes with a lower threshold and improved sensitivity. In this paper the results of a feasibility study on the design of Large Cherenkov Telescopes with diameters of up to 30 m are presented. The feasibility investigations done by MAN Technologie in Mainz, Germany had to take into account the required mechanical performance, costs, and local fabrication and erection capabilities of the countries in which the telescopes should be erected.