Physical Considerations for Cherenkov Radiation Based Coincidence Time Resolution Measurements in BGO

Exploiting the Cherenkov luminescence from 511 keV photoelectric interactions is a potential solution to re-introduce BGO scintillators in time-of-flight positron emission tomography (TOF-PET). Recent improvements in vacuum- and near- ultra-violet high density (VUV- and NUV-HD) silicon photomultiplier (SiPM) technology combined with efficient data post-processing methods, make it possible to access timing information from the relatively few Cherenkov photons emitted. To achieve good coincidence time resolution (CTR) also requires low noise and fast readout electronics with small effective capacitance, which is possible by employing bootstrapping techniques.In this summary, we report the CTR evaluation of the new VUV-HD and NUV-HD enhanced SiPMs. Results using a (i) standard electronic board, and a (ii) custom designed board for timing measurements, are shown. After applying state-of-the-art correction methods, values below 400 ps CTR FWHM have been reported for 3×3 mm 2 BGO crystals with lengths ranging from 3 to 15 mm, thus indicating the excellent performance of new SiPM technology combined with our custom design board.