Particle Initial Energy Choice in Proton Computed Tomography for Medical Purposes

In the earliest works devoted to proton computed tomography (pCT) it was shown that the advantage of pCT image reconstruction appears when the energy is chosen as small as possible but sufficient to pass the object. At the same time there are two effects that work on the contrary, increasing the necessary irradiation dose with decreasing proton energy. In this work the radiation dose dependence from the proton initial energy was studded using analytical formulas and computer simulation. The carried out investigation shows that the irradiation dose practically does not depend on the proton energy except at the small energy region very close to the minimal energy.