24-28 February 2020
Budker Institute of Nuclear Physics
Asia/Novosibirsk timezone

MPGD-based photon detectors for the upgrade of COMPASS RICH-1 and beyond

27 Feb 2020, 16:50
Contributed Oral Micropattern gas detectors Particle Identification


Dr Shuddha Shankar Dasgupta (Post Doc Researcher)


After pioneering gaseous detectors of single photon for RICH applications using solid state Photo Cathodes (PC) within the RD26 collaboration and by the realization of the MWPCs with CsI PC for the RICH detector of the COMPASS experiment at CERN SPS, in 2016 we have upgraded COMPASS RICH by novel gaseous photon detectors based on MPGD technology. Four new photon detectors, covering a total active area of 1.5 square m, have been installed in order to cope with the challenging efficiency and stability requirements of the COMPASS physics programme. The new detector architecture consists in a hybrid MPGD combination: two layers of THGEMs, the first of which also acts as a reflective PC thanks to CsI coating, are coupled to a bulk Micromegas on a pad-segmented anode; the signals are read-out by analog F-E based on the APV-25 chip. These detectors are the first application in an experiment of MPGD-based single photon detectors. Presently, we are further developing the MPGD-based PDs to make them adequate for setups at the future EIC collider. A compact collider setup imposes to construct a RICH with a short radiator length, hence limiting the number of photons. The last can be increased by detecting the photons in the far UV region. However, as standard fused-silica windows are opaque below 165 nm, a windowless RICH approach represents a possible choice. Another challenge is the need of improved space resolution, related to the shorter lever arm. All aspects of the COMPASS RICH-1 Photon Detectors upgrade are presented, including R&D, engineering, mass production, quality assessment and performance as well as the on-going development for collider application.

Primary author

Dr Shuddha Shankar Dasgupta (Post Doc Researcher)

Presentation Materials