Proton energy measurements using a NaI(T1) scintillator

Energy measurements of protons using a NaI(T1) scintillator for energies around 100 MeV and higher, have the disadvantage that the response of the crystal has a non-linear light output versus energy relation. An experimental calibration of the light output of the crystal into energy would require a number of different monoenergetic proton beams. We have developed a method for calibrating the non-linear light output into energy using relative measurements of the energy. By applying this relative method, it is also possible to determine the absolute initial energy of the protons before they hit the experimental set-up.