Time Calibration of phenoPET based on the Lu-176 Background of LYSO

The digitally generated timemarks from more than 2000 individual detector elements in the pheno PET scanner show individual time offsets. These offsets (or skews) are in the range of ± 1 ns while the actual time resolution of each element is below 250 ps. Thus, the time resolution of the entire system will be highly improved by correcting these offsets. This paper presents a precise correction method based on measurements of the LYSO background radiation. The Coincidence Resolving Time for the entire scanner could be improved from 1.45 ns to less than 300 ps.