A new solution for mirror coating in $\gamma$-ray Cherenkov Astronomy

TL;DR

This paper introduces a novel 28-layer mirror coating for gamma-ray Cherenkov telescopes, achieving over 90% reflectance in key wavelengths, enhancing light response and detection efficiency.

Contribution

The study presents a new multilayer mirror coating design optimized for gamma-ray Cherenkov telescopes, combining numerical simulation and experimental validation.

Findings

Reflectance above 90% in 300-550 nm range

Successful development of a multilayer SiO₂-TiO₂-HfO₂ coating

Potential improvement in telescope light response

Abstract

In the $\gamma$-ray Cherenkov Astronomy framework mirror coating plays a crucial role in defining the light response of the telescope. We carried out a study for new mirror coating solutions with both a numerical simulation software and a vacuum chamber for small sample production. In this article, we present a new mirror coating solution consisting of a 28-layer interferometric SiO$_{2}$-TiO$_{2}$-HfO$_{2}$ design deposited on a glass substrate, whose average reflectance is above $90\%$ for normally incident light in the wavelength range between 300 and 550 nm.