An outdoor test facility for the Cherenkov Telescope Array mirrors

TL;DR

This paper describes the development of an outdoor test facility in Argentina for evaluating the optical and mechanical performance of lightweight mirror facets for the Cherenkov Telescope Array under real atmospheric conditions.

Contribution

It introduces a new outdoor testing setup at a CTA candidate site to monitor mirror facet performance in situ, providing valuable data for future telescope construction.

Findings

Initial data on mirror facet durability and optical stability

Insights into environmental effects on lightweight mirror structures

Assessment of mirror performance over time

Abstract

The Cherenkov Telescopes Array (CTA) is planned to be an Observatory for very high energy gamma ray astronomy and will consist of several tens of telescopes which account for a reflective surface of more than 10000 m$^2$. The mirrors of these telescopes will be formed by a set of facets. Different technological solutions, for a fast and cost efficient production of light-weight mirror facets are under test inside the CTA Consortium. Most of them involve composite structures whose behavior under real observing conditions is not yet fully tested. An outdoor test facility has been built in one of the candidate sites for CTA, in Argentina (San Antonio de los Cobres [SAC], 3600m a.s.l) in order to monitor the optical and mechanical properties of these facets exposed to the local atmospheric conditions for a given period of time. In this work we present the preliminary results of the first Middle Size Telescope (MST) mirror-monitoring campaign, started in 2013.