Ewa Oponowicz successfully defended her PhD thesis
On 24th March 2021 Ewa Oponowicz, the OMA Fellow based at the University of Manchester and the Cockcroft Institute, successfully defended her PhD thesis. The thesis titled 'Superconducting gantry for proton therapy and proton computed tomography' was a study on a novel beam delivery system capable of transporting protons of energies between 70-330 MeV. This single system can hence serve for two purposes: proton therapy (70-250 MeV) and proton imaging (330 MeV), i.e. proton computed tomography, a patient imaging method which can improve the accuracy of proton therapy planning.
Whilst the rigidity of a proton beam for imaging increases to 2.84 Tm (from max. 2.42 Tm for a treatment beam), the gantry is based on superconducting magnets and can be housed in a conventional proton treatment room. Pure dipoles and combined-function magnets (dipole and quadrupole components) are of canted-cosine-theta arrangement wound with a NbTi wire. The achromatic lattice of the gantry allows for an energy acceptance of +/-5% and eliminates the need of ramping the superconducting magnets during the treatment. The moderate energy acceptance, combined with a range shifter mounted in the nozzle, results in turn in high particle transmission and therefore, opens up possibilities towards proton FLASH therapy.
Additionally, within her thesis, Ewa also worked on a beam energy degrader optimisation. The derader could be potentially placed between the two achromatic sections of the gantry to enable a multi-layer treatment with static magnetic field of the first bending section. She examined various degrader geometries and compared a typical graphite with a novel boron carbide degrader to improve the particle transmission through the energy reduction system.
Since completing the thesis, Ewa has worked as a Fellow in the Beam Transfer Physics section at CERN. Her current project focuses on beam dynamics studies for GaToroid, a novel stationary system for heavy ion therapy.