PhD Success!

Congratulations to Cameron Robertson who on 4th July 2024 successfully defended his thesis, titled "Homogeneous Dose Delivery for Very High Energy Electron Beams".

My research has been based on the delivery of Very High Energy Electrons (VHEEs) for cancer treatment, specifically the enlargement and flattening of beams to provide dose conformality. The VHEE regime is usually defined as being between 50-250MeV. The methods for this beam modification were chosen to be compatible for inducing the FLASH effect - a phenomenon where healthy tissue sparing characteristics are observed during radiation therapy at ultra-high-dose-rates (typically delivered within 100ms). My work has included optics studies, optimisations and sensitivity analysis for e-GaToroid, a novel concept for a static VHEE gantry based on circularly symmetric toroidal magnets, which could be capable of delivering multiple beams within a FLASH timescale. I've also studied the implementation of dual-scattering foils (beam inserts for enlargement and flattening) for 200MeV electrons. This was carried out with extensive Monte-Carlo simulations, with which I developed a novel method for automated design and optimisation of these systems within arbitrary geometries and beam conditions. I then designed successive dual-scattering systems for experimental studies of beam evolution in water phantoms at the CERN Linear Electron Accelerator for Research (CLEAR), which compared well with simulations. In collaboration with the CLEAR operators, a dual-scattering system was installed in the beamline to allow the delivery of large, uniform beams for Users. This system is now well characterised and is in use for chemistry and radiobiological studies in the CLEAR User programme.

Cameron Robertson (middle), internal examiner Prof. Phil Burrows (left) and external examiner Dr Deepa Angal-Kalinin (right)