Proton-induced radiation damage of crystal scintillators

We report results from a proton beam test to measure radiation damage and activation in crystal scintillators. Samples were irradiated with the 45 MeV proton beam from the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences. Proton beam fluxes of 0.5 to 10 nA were used for the test. A PMT was attached to one side of the crystal and a 25 Mhz FADC (Flash Analog to Digital Converter) was used for the signal digitization. The light output and the energy resolution of the scintillation crystals with 662-keV gamma rays from a ¹³⁷Cs radioactive source was measured prior to and after proton irradiation, and the result were compared with each other. Apart from an increase in the intrinsic activity, we did not observe any significant effect on the scintillation light output or the energy resolution of the LYSO crystal.