Development of Electro-Optic Beam Position Monitors for the Large Hadron Collider

A collaboration between the CERN Beam Instrumentation group and Royal Holloway, University of London (RHUL) aims to develop novel optical Beam Position Monitors. The long term objective is to build a system to monitor proton bunch rotation induced by crab-cavities at the future High Luminosity Large Hadron Collider, by exploiting the fast time response of electro- optic crystals. A change in the polarization of light passing through the crystal is induced by the electro-optic (Pockels) interaction with the passing charged particle bunch. Rapid detection (lOGHz bandwidth) of the optical signals from pick-ups placed on opposite sides of the beam pipe, allow transverse offsets of particles within a bunch to be monitored, at different positions along the ns bunch. The RHUL PhD student will join this collaborative experimental program to develop the optical BPM for tests in the CERN accelerator chain, including tests of a prototype EO-BPM that has been installed during 2016 in the CERN SPS. The student will evaluate initial results in comparison with electromagnetic simulations, and extend the design to an interferometric configuration to assess the potentially improved sensitivity. Pending successful tests at the SPS, a prototype EO-BPM for the LHC will be designed and manufactured for bench
tests at RHUL and CERN. The position will be based at Royal Holloway, University of London, and travel to CERN is expected. The student will benefit from the support and training in the RHUL John Adams Institute, including lectures in accelerator physics, and the wider network of the new HL-LHC-UK collaboration.