| Popis: |
Accelerators play a key role in the delivery of radiotherapy for treatment of cancer and other medical conditions. Proton therapy has the benefit of more localised delivery of dose to deep seated tumour volumes in comparison to treatment using x-rays or electrons. The accelerators currently used for proton therapy are cyclotrons and synchrotrons, which each have certain advantages and disadvantages. It has been proposed that accelerators of a fixed field alternating gradient (FFAG) design may combine some of the advantages and avoid some of the disadvantages of the existing machines. This thesis looks at the use of synchrotrons as a benchmark for the delivery of proton therapy, and then at how FFAGs may improve upon treatment delivery. Particular attention is paid to the beam dynamics issues, including comparisons between simulations and experimental data taken with the EMMA non-scaling FFAG at Daresbury. The results of the comparisons show that simulation is able to predict the behaviour of a particle bunch in a real machine. The simulation tools are then used to evaluate the design of FFAGs incorporating resonant extraction techniques. In principle, resonant extraction could overcome some problems of kicker based extraction methods. The design study highlights technical challenges that would need to be overcome before resonant extraction could be implemented as a beneficial method for a proton therapy FFAG. |
