Novel MPGD based Detectors of Single Photons in COMPASS RICH-1

TL;DR

This paper presents the development, integration, and successful operation of novel hybrid MPGD photon detectors in the COMPASS RICH-1 system, enhancing single photon detection capabilities for hadron identification.

Contribution

Introduction of a hybrid MPGD photon detector with THGEMs and MicroMegas for improved performance in RICH-1 at CERN.

Findings

Detectors operated stably during 2017 data taking.

Successful integration of CsI-coated THGEMs as reflective photocathodes.

Enhanced single photon detection in the COMPASS experiment.

Abstract

COMPASS is a fixed target experiment at CERN SPS aimed to study Hadron Structure and Spectroscopy. Hadron Identification in the momentum range between 3 and 55 GeV/c is provided by a large gaseous Ring Imaging Cherenkov Counter (RICH-1). To cope with the challenges imposed by the new physics program of COMPASS, RICH-1 have been upgraded by replacing four MWPCs based photon detectors with newly developed MPGD based photon detectors. The architecture of the novel detectors is a hybrid combination of two layers of THGEMs and a MicroMegas. The top of the first THGEM is coated with CsI acting as a reflective photo-cathode. The anode is segmented in pads capacitively coupled to the APV-25 based readout. The new hybrid detectors have been commissioned during 2016 COMPASS data taking and stably operated during 2017 run. In this paper all aspects of the novel photon detectors for COMPASS RICH-1 are discussed.