An instrumented baffle for the Advanced Virgo Input Mode Cleaner End Mirror

TL;DR

This paper presents a novel instrumented baffle for the Virgo interferometer's input mode cleaner, demonstrating its design, testing, and operational performance as a prototype for future upgrades in gravitational wave detectors.

Contribution

It introduces a new instrumented baffle design with comprehensive testing and validation, serving as a prototype for future instrumentation in gravitational wave observatories.

Findings

Good agreement with stray light simulations

Successful operation during experiments

Effective performance in optical and vacuum tests

Abstract

A novel instrumented baffle surrounding the suspended end mirror in the input mode cleaner cavity of the Virgo interferometer was installed in spring 2021. Since then, the device has been regularly operated in the experiment and the obtained results indicate a good agreement with simulations of the stray light inside the optical cavity. The baffle will operate in the upcoming O4 observation run, serving as a demonstrator of the technology designed to instrument the baffles in front of the main mirrors in time for O5. In this paper we present a detailed description of the baffle design, including mechanics, front-end electronics, data acquisition, as well as optical and vacuum tests, calibration and installation procedures, and performance results.