A New Technology for Fast Two-Dimensional Detection of Proton Therapy Beams

Figure 17

A proton Bragg peak measurement using the Micromegas chamber compared with Geant4 simulation of the IBA Universal Nozzle, Varian MLC, and the Micromegas detector and water column. Agreement is within 5% across the water-equivalent depth range from 7.5–19.5 cm. The curves are normalized at the peaks. The error bars on the Micromegas measurement represent the 0.8% dose reproducibility (see Figure 9) and the error bars on the simulation represent the Monte Carlo sample variance.