Development of a Novel Transverse Beam Profile and Emittance Monitor for the CERN Proton Synchrotron

  • Hampus Sandberg

Student thesis: Phd


Beam profile and emittance monitoring is essential to understand the dynamic behaviour of the ensemble of particles in an accelerator beam. A non-invasive measurement of the beam profile ensures reliable measurements. One such device is the beam gas Ionisation Profile Monitor (IPM), which relies on detecting the ionisation products from the interaction between residual gas molecules in the vacuum of the accelerator and the beam particles. Traditional detectors in IPMs have limited the instruments reliability and performance. A novel approach using Timepix3 pixel detectors is explored in this thesis project which enables direct detection of ionisation electrons with a precise time resolution. A radiation hard readout system was developed to allow the maximum detection performance of the pixel detectors and beam measurements were recorded during 2018. A beam profile reconstruction method was developed that takes advantage of the information recorded by the Timepix3 detectors to identify and only select events that are associated with ionisation electrons. From these events, a beam profile was reconstructed and the beam size calculated by fitting a Gaussian model to the beam profile data or by calculating the RMS beam size directly. During 2018 a prototype IPM with pixel detectors was installed in the Proton Synchrotron at CERN. Beam profile measurements recorded with this instrument demonstrated the ability to measure the beam profile continuously throughout the beam cycle in the accelerator. Expected beam dynamics effects such as adiabatic damping and oscillations during transition crossing were observed with the instrument. The time resolution of the pixel detectors enabled bunch-by-bunch measurements of the beam profile by integrating the recorded events separately for each bunch over multiple turns.
Date of Award1 Aug 2021
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorHywel Owen (Supervisor) & William Bertsche (Supervisor)


  • Timepix3
  • Hybrid Pixel Detector
  • BGI
  • CERN
  • Beam Instrumentation
  • Beam Profile Monitor
  • IPM

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