Expected proton signal sizes in the PRaVDA Range Telescope for proton Computed Tomography

Proton radiotherapy has demonstrated benefits in the treatment of certain cancers.
Accurate measurements of the proton stopping powers in body tissues are required in order to fully
optimise the delivery of such treaments. The PRaVDA Consortium is developing a novel, fully
solid state device to measure these stopping powers. The PRaVDA Range Telescope (RT), uses
a stack of 24 CMOS Active Pixel Sensors (APS) to measure the residual proton energy after the
patient. We present here the ability of the CMOS sensors to detect changes in the signal sizes as
the proton traverses the RT, compare the results with theory, and discuss the implications of these
results on the reconstruction of proton tracks.