Characterization and scintillation studies of a solid-state photomultiplier

The solid-state photomultiplier (SSPM) is a relatively new semiconductor based photodetector that, by using hundreds of micro silicon Geiger APDs, possesses high gain (105105–106106) and low noise while needing only low voltage (40–60 V) to operate. The fast response and high intrinsic gain of SSPMs makes them attractive for timing applications, in particular for positron emission tomography (PET). Here we present the results from the characterization of a 1×1mm2 SSPM (SSPM-050701GR-TO18, Photonique SA). Several intrinsic SSPM characteristics were measured such as gain, dark noise, and linearity. Single photon spectra were also collected. Additionally, scintillation studies were performed. The SSPM was coupled to CsI:Tl and LSO scintillation crystals and exposed to various common laboratory radionuclides to measure photopeak energy resolutions. The linearity of the SSPM, when coupled with a scintillator, was also measured. Using a 22Na source (511 keV annihilation photons) and LSO, the SSPM FWHM energy resolution is 14.4%±0.2%14.4%±0.2% and the estimated coincidence FWHM timing resolution is 0.84ns±0.02ns.