US Patent 10231679 Proton radiography system incorporating time-of-flight measurement

A proton radiography system includes a source of a proton beam at nonrelativistic energy, directed on a beam path to an object to be imaged; one or more time-of-flight (TOF) detectors arranged on the beam path to detect incidence of beam protons and generate output signals indicative thereof with a time resolution substantially less than a time of flight of the protons; and a data acquisition and analysis subsystem coupled to the TOF detectors to receive the respective output signals and (1) calculate TOF values for respective bunches of one or more protons, (2) convert the TOF values to proton velocity values and proton energy values, and (3) use the proton energy values to calculate a corresponding value for a physical property of the object along the beam path, and incorporate the value into elements of a radiographic image of the object stored or displayed in the system.