The Cherenkov Telescope Array (CTA), currently in its early design phase, is a proposed new project for groundbased gamma-ray astronomy with at least 10 times higher sensitivity than current instruments. CTA is planned to consist of several tens of large Imaging Atmospheric Cherenkov Telescopes (IACTs) with a combined reflective surface of up to 10,000 m². The challenge for the future CTA array is to develop lightweight and cost efficient mirrors with high production rates, good longterm durability and adequate optical properties. The technologies currently under investigation comprise different methods of carbon fibre/epoxy based substrates, sandwich concepts with cold-slumped surfaces made of thin float glass and different structural materials like aluminum honeycomb, glass foam or PU foam inside, and aluminum sandwich structures with either diamond milled surfaces or reflective foils. The current status of the mirror development for CTA will be summarized together with investigations on the improvement of the reflective surfaces and their protection against degradation.

Date Published: 31 August 2009
PDF: 6 pages
Proc. SPIE 7437, Optics for EUV, X-Ray, and Gamma-Ray Astronomy IV, 743712 (31 August 2009); doi: 10.1117/12.827726

Published in SPIE Proceedings Vol. 7437:
Optics for EUV, X-Ray, and Gamma-Ray Astronomy IV
Stephen L. O'Dell; Giovanni Pareschi, Editor(s)