A Central Laser Facility for the Cherenkov Telescope Array

TL;DR

This paper discusses the design and potential calibration benefits of a Central Laser Facility for the Cherenkov Telescope Array, aiming to improve calibration accuracy and atmospheric monitoring.

Contribution

It introduces a proposed laser-based calibration system for CTA, including simulation results for various configurations to optimize performance.

Findings

Potential calibration precision better than 10%

Simulations show optimal laser configurations

Enables long-term sensitivity monitoring

Abstract

A Central Laser Facility is a system often used in astroparticle experiments based on arrays of fluorescence or Cherenkov light detectors. The instrument is based on a laser source positioned at a certain distance from the array, emitting fast light pulses in the vertical direction with the aim of calibrating the array and/or measuring the atmospheric transmission. In view of the future Cherenkov Telescope Array (CTA), a similar device could provide a calibration of the whole installation, both relative, i.e. each individual telescope with respect to the rest of the array, and absolute, with a precision better than 10%, if certain design requirements are met. Additionally, a precise monitoring of the sensitivity of each telescope can be made on time-scales of days to years. During calibration runs of the central laser facility, all detectors will be pointed towards the same portion of the laser beam at a given altitude. Simulations of the possible configurations of a Central Laser Facility for CTA (varying laser energy, pointing height and distance from the telescopes) have been performed