Development of the optical system for the SST-1M telescope of the Cherenkov Telescope Array observatory

TL;DR

This paper presents the design and performance evaluation of the optical system for the SST-1M telescope, a prototype for the Cherenkov Telescope Array, focusing on mirror configuration and alignment for optimal Cherenkov light detection.

Contribution

It introduces a novel optical system design for the SST-1M telescope, including mirror configuration, alignment, and stability analysis, tailored for Cherenkov light collection in CTA.

Findings

Effective collection area of 6.47 m2

Mirror alignment system ensures dish stability

Optical performance meets Cherenkov detection requirements

Abstract

The prototype of a Davies-Cotton small size telescope (SST-1M) has been designed and developed by a consortium of Polish and Swiss institutions and proposed for the Cherenkov Telescope Array (CTA) observatory. The main purpose of the optical system is to focus the Cherenkov light emitted by extensive air showers in the atmosphere onto the focal plane detectors. The main component of the system is a dish consisting of 18 hexagonal mirrors with a total effective collection area of 6.47 m2 (including the shadowing and estimated mirror reflectivity). Such a solution was chosen taking into account the analysis of the Cherenkov light propagation and based on optical simulations. The proper curvature and stability of the dish is ensured by the mirror alignment system and the isostatic interface to the telescope structure. Here we present the design of the optical subsystem together with the performance measurements of its components.