Influence of PET detector for OpenPET by heavy charged particle irradiation

We proposed ''OpenPET'' which is separated into two detector rings. The OpenPET can be used as in-beam PET thanks to the open space between the two detector rings. The detectors of the OpenPET are exposed by secondly particles from targets. The purpose of this study is investigation of influence of the secondly particles to the positron emission tomography (PET) detector. We exposed scintillators typically used in PET detectors and measured influence from irradiation. After irradiation, count rates of the PET detectors were increased. In addition, a lot of peaks of gamma rays form scintillators were appeared in the spectra measured by germanium detector and a beta spectrum was obtained by a photomultiplier tube. It was caused by activation of the scintillators by secondly particles. The energies of a lot of these gamma rays and beta particles are under 1 MeV. Since the target energy of PET detectors is 511 keV, they have possibility to degrade the performance of PET detectors. (author)