# The NA62 RICH detector

## TL;DR

The NA62 RICH detector at CERN uses Neon gas and a mirror-photomultiplier system to suppress muon contamination, measure pion timing, and trigger charged tracks, with detailed construction and initial performance results.

## Contribution

This paper details the design, construction, and initial performance of the NA62 RICH detector, a novel system for particle identification and timing in a high-energy physics experiment.

## Key findings

- Achieved muon suppression factor of over 100.
- Measured pion timing resolution of approximately 100 ps.
- Demonstrated detector performance during initial runs.

## Abstract

The RICH detector of the NA62 experiment at CERN SPS is required to suppress $\mu^+$ contamination in $K^+ \to \pi^+ \nu \bar\nu$ candidate events by a factor at least 100 between 15 and 35 GeV/c momentum, to measure the pion arrival time with $\sim 100$ ps resolution and to produce a trigger for a charged track. It consists of a 17 m long tank filled with Neon gas at atmospheric pressure. \v{C}erenkov light is reflected by a mosaic of 20 spherical mirrors placed at the downstream end of the vessel and is collected by 1952 photomultipliers placed at the upstream end. The construction of the detector will be described and the performance reached during first runs will be discussed.