Design of the TORCH detector: A Cherenkov based Time-of-Flight system for particle identification

The LHCb detector at the LHC collider has been very successfully operated over the past years, providing new and profound insights into the Standard Model, in particular through study of $b$-hadrons to achieve a better understanding of CP violation. One of the key components of LHCb is its particle identification system, comprised of two RICH detectors, which allow for high precision separation of particle species over a large momentum range. In order to retain and improve the performance of the particle identification system in light of the LHCb upgrade, the TORCH detector has been proposed to supplement the RICH system at low momentum (2-10 GeV/c). The TORCH detector provides (charged) particle identification through precision timing of particles passing through it. Assuming a known momentum from the tracking, it is possible to derive the species of a particle from the time of flight from its primary vertex. This measurement is achieved by timing and combining photons generated in a solid radiator. The geometry of the detector (composed of large plates of fused silica) is such that the generated Cherenkov photons are trapped inside the plate by total internal reflection, and propagate to the periphery of the radiator. Here they are projected onto a plane of photodetectors, comprised of purpose designed MCP-PMTs. The photons detected for a track are combined into a time stamp for each particle, finally resulting in the time of flight being measured so that the particle identity can be derived. The final goal of the TORCH project is to prove the feasibility and desirability of the TORCH detector as an addition to the LHCb particle identification system. This thesis will describe the progress that has been made towards the key objectives of the TORCH project; in particular the development of optics, detectors and electronics.