Demonstration of low energy proton radiography on an 11-MeV cyclotron

Lens focused proton radiograph on thin objects is demonstrated using an 11-MeV proton cyclotron at China Academy of Engineering Physics. The proton beam exiting from the tested objects is focused onto the image plane by a magnetic lens system mitigating image blur caused by multiple Coulomb scattering. Both simulations and experiments show that clear images can be obtained with a lens system for the objects with thickness up to 2.7 × 10^-2 g/cm² and the error for the areal density measurement is measured to be less than 2.3%. For the objects with thickness between 2.7 × 10^-3 g/cm² and 2.7 × 10^-2 g/cm², 100-200 μm of spatial resolution is achieved.