Alec York

Abstract:

The TORCH time-of-flight detector is part of a proposed upgrade of the LHCb experiment, foreseen for the high-luminosity phase of the LHC. The TORCH detector provides particle identification of hadrons in the sub-10 GeV/c momentum range, exploiting the prompt production of Cherenkov photons in an array of fused-silica plates. Photons are propagated to the periphery of the detector via total internal reflection, where they are focused by a cylindrical mirror onto an array of fast-timing MCP-PMT photon detectors. In order to achieve the design goals of TORCH, individual photons must be timed to 70ps precision or better. The development of the MCP-PMTs, the mechanical design and assembly strategy of a full-scale TORCH detector module, plus its system-level validation in a test beam are described. A validation of timing references, the optical integrity across glue joints and the readout integration are presented.

Abstract:

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.

Abstract:

MOSAIC is the Multi-Object Spectrograph (MOS) for the 39m Extremely Large Telescope (ELT) of the European Southern Observatory (ESO), with unique capabilities in terms of multiplex, wavelength coverage and spectral resolution. It is a versatile multi-object spectrograph working in both the Visible and NIR domains, designed to cover the largest possible area (∼40 arcmin2) on the focal plane, and optimized to achieve the best possible signal-to-noise ratio on the faintest sources, from stars in our Galaxy to galaxies at the epoch of the reionization. In this paper we describe the main characteristics of the instrument, including its expected performance in the different observing modes. The status of the project will be briefly presented, together with the positioning of the instrument in the landscape of the ELT instrumentation. We also review the main expected scientific contributions of MOSAIC, focusing on the synergies between this instrument and other major ground-based and space facilities.