Developing next generation fast-timing photon-detectors

The ability to distinguish different types of charged particles is key to the programme of measurements that will be carried out with the LHCb experiment at the Large Hadron Collider.

The Time Of internally Reflected Cherenkov light detector (TORCH) aims to separate charged particles based on their time-of-flight from their production point to a timing detector placed 9.5m downstream.

At a fixed momentum, different types of particle will take more or less time to traverse the distance depending on how massive they are. Key to accurately separating the particles is a precise measurement of the particle arrival time. The TORCH project aims to use Cherenkov radiation emitted by particles traversing a quartz bar as a timing signal.

To reach the precision needed for the LHCb experiment, individual Cherenkov photons needed to be timed to a few tens of picoseconds. The fast photon timing is provided by an array of micro-channel-plate photomultipliers (MCP-PMTs).

Information from multiple photons can then be combined to achieve a very accurate measurement of a particles time-of-flight.

The latest TORCH prototype features MCP-PMTs produced in collaboration with Photek Ltd, a leading UK manufacturer of photon detector devices.

The CASE student will work with scientists and engineers at the University of Warwick and Photek on the simulation and characterisation a new generation of MCP-PMT that will be needed to cope with the rates of photons that will be seen when operating at the Large Hadron Collider.

Simulations of the expected collision environment indicate that the rates are beyond the capabilities of existing devices.