Multiple Coulomb Scattering with Proton Therapy Beams and Thin Scintillators

Proton Computed Tomography (PCT) is a long sought-after medical imaging modality, limited by its lower spatial resolution when compared to other imaging modalities like X-Ray Computed Tomography. Multiple Coulomb Scattering (MCS) and other particle interactions are to blame for the lower spatial resolution in previous PCT attempts. We work towards the goal of producing a viable PCT by using thin scintillator crystals and a digital camera, relating the light produced by the interactions between the crystal and the proton beam and the relative stopping power (RSP), as well as measuring the standard deviation of the gaussian signal produced by the crystal/beam interaction to obtain the MCS angle for different beam energies. We compare experimental data to simulated data from GEANT4 to verify the efficacy of this setup. Finally, we conclude by demonstrating that this setup is sensitive enough to differentiate between full-beam signal and signal produced by placing a phantom before the scintillator crystal, paving the way for future PCT imaging.