Energy spectra and their calibration of four-layer DOI detector for brain PET scanner: jPET-D4

A depth of interaction (DOI) detector is being developed for the brain PET scanner, jPET-D4. We introduce a light output correction procedure to compensate for variations among the crystal elements in the DOI detector. Under uniform irradiation with 511 keV gamma rays, we estimate the light output of each crystal element by identifying each crystal, and generate a look-up table (LUT) for light output correction. The variation of light output of each crystal element is 18%. We evaluate the energy resolution of all crystal elements. The energy resolution before light output correction was 40%. Using DOI information, an energy resolution of 18% has been achieved after light output correction. We present and analyze the crystal position dependence of energy spectra due to intercrystal scattering among the multiple crystal elements in the DOI detector