The TORCH time-of-flight detector for Upgrade II of the LHCb experiment

Journal article

The TORCH (Time Of internally Reflected Cherenkov light) detector is proposed for the high-luminosity Upgrade II of the LHCb experiment. The aim of TORCH is to measure time-of-flight with a 15 ps resolution per charged-particle, providing particle identification over the momentum range 2–15 GeV/c. TORCH is to be located approximately 9.5 m downstream of the LHCb interaction point, and comprises 18 modules of highly-polished 1 cm-thick quartz plates, each of 250×66cm². Cherenkov photons, radiated in the quartz, are focused onto an array of fast-timing micro-channel-plate detectors (MCP-PMTs) that each have a pixelation of 8 × 64 within an active area of 5.3 × 5.3 cm². Test-beam studies have previously shown that a timing resolution better than 100 ps per single photon can be achieved on a half-height module. Recent advances in the development of a 16 × 96 pixelated MCP-PMT are described. A full-height module is being developed with a light-weight carbon-fibre support structure. A novel exo-skeleton jigging system is used to bond the optical elements and support each module during installation.

Authors: Blake, T; Cicala, F; Conneely, T; Cussans, D; Davidson, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
• Volume: 1069
• Article number: 169797
• Publication date: 2024-08-26
• Acceptance date: 2024-08-24
• DOI: 10.1016/j.nima.2024.169797
• EISSN: 1872-9576
• ISSN: 0168-9002
• Language: English
• Keywords: particle identification; time-of-flight