Evaluation of Two SiPM Arrays for Depth-Encoding PET Detectors Based on Dual-Ended Readout

In this article, two latest silicon photomultiplier (SiPM) arrays from Hamamatsu and Broadcom were evaluated for high-resolution dual-ended readout positron emission tomography (PET) detectors. The Hamamatsu SiPM array and the Broadcom SiPM array are both $8\times8$ arrays of $\sim 4\times4$ mm² SiPMs and were fabricated using 50 and 30- $\mu \text{m}$ microcells, respectively. To evaluate the SiPM arrays for PET applications, two dual-ended readout PET detectors were fabricated, while each detector contains two identical SiPM arrays coupled to both ends of the same $20\times20$ lutetium yttrium oxyorthosilicate array with a pitch size of 1.5 mm and a length of 20 mm. The results show that the two detectors provide excellent performance for high-resolution PET applications. At a temperature of $23~^\circ \text{C}$ , the flood histogram quality, energy resolution, depth-of-interaction resolution, and timing resolution obtained using the Hamamatsu SiPM arrays at a bias voltage of 41.5 V are 4.83 ± 0.64, 10.5 ± 3.5%, 1.88 ± 0.17 mm, and 0.86 ± 0.13 ns, respectively, and those obtained using the Broadcom SiPM arrays at a bias voltage of 32.5 V are 4.01 ± 0.53, 15.7 ± 3.6%, 2.01 ± 0.19 mm, and 0.88 ± 0.11 ns, respectively.