Status of the TORCH time-of-flight project

TL;DR

TORCH is a novel time-of-flight detector designed for precise particle identification up to 10 GeV/c, utilizing Cherenkov radiation and MCP-PMTs, with promising preliminary results from a small-scale demonstrator.

Contribution

This paper reports the development and testing of a small-scale TORCH demonstrator, demonstrating achievable single-photon resolution and discussing its potential for LHCb upgrade.

Findings

Single-photon resolution better than 100 ps achieved

Successful operation of a small-scale demonstrator in beam tests

Potential for full-scale TORCH detector in LHCb upgrade

Abstract

TORCH is a time-of-flight detector, designed to provide charged pi/K particle identification up to a momentum of 10 GeV/c for a 10 m flight path. To achieve this level of performance, a time resolution of 15 ps per incident particle is required. TORCH uses a plane of quartz of 1 cm thickness as a source of Cherenkov photons, which are then focussed onto square Micro-Channel Plate Photomultipliers (MCP-PMTs) of active area 53 x 53 mm^2, segmented into 8 x 128 pixels equivalent. A small-scale TORCH demonstrator with a customised MCP-PMT and associated readout electronics has been successfully operated in a 5 GeV/c mixed pion/proton beam at the CERN PS facility. Preliminary results indicate that a single-photon resolution better than 100 ps can be achieved. The expected performance of a full-scale TORCH detector for the Upgrade II of the LHCb experiment is also discussed.