Radiotherapy, most commonly with x-rays, is a widely used and effective form of cancer treatment. Using protons instead of x-rays allows better localisation of the radiation dose to the tumour and therefore less damage the surrounding healthy tissue. New imaging techniques such as proton Computed Tomography (pCT) can improve further this targeting. Fixed-Field Alternating-Gradient accelerators (FFAG) offer rapid acceleration of protons with variable energy extraction up to energies required for pCT. FFAGs may offer advantages over cyclotrons, synchrotrons and linacs currently used to provide these beams.
Schematic of the NORMA racetrack lattice.
NORMA (Normal-conducting Racetrack Medical Accelerator) is a novel machine with normal conducting magnets, a racetrack layout and higher energy reach to enable pCT. The racetrack shape allows more efficient use of space, by moving space from between magnets in the arc in to the two straight sections where it can be used to simplify the challenges of injecting and extracting the beam from the ring. The article recently published by the Cockcroft Institute presents the concept, details the optimisation of the design and the effects on the dynamics of introducing the race track straights.
The work was performed in team led by Dr Rob Appleby, with Dr Sam Tygier, Dr Hywel Owen and Dr Jimmy Garland.