Prototyping Hexagonal Light Concentrators Using High-Reflectance Specular Films for the Large-Sized Telescopes of the Cherenkov Telescope Array

TL;DR

This paper presents a prototype hexagonal light concentrator with high-reflectance specular films designed for Cherenkov Telescope Array's large telescopes, improving photon collection efficiency and lowering energy thresholds.

Contribution

It introduces a novel high-reflectance specular film and demonstrates its application in a light concentrator prototype for enhanced telescope performance.

Findings

Prototype achieves 95-105% collection efficiency at key angles.

High-reflectance film covers inner surfaces, boosting photon collection.

Design and performance validated through measurements.

Abstract

We have developed a prototype hexagonal light concentrator for the Large-Sized Telescopes of the Cherenkov Telescope Array. To maximize the photodetection efficiency of the focal-plane camera pixels for atmospheric Cherenkov photons and to lower the energy threshold, a specular film with a very high reflectance of 92-99% has been developed to cover the inner surfaces of the light concentrators. The prototype has a relative anode sensitivity (which can be roughly regarded as collection efficiency) of about 95 to 105% at the most important angles of incidence. The design, simulation, production procedure, and performance measurements of the light-concentrator prototype are reported.