Performance of the FlexToT v2 ASIC on the readout of different detector designs for PET

A new version of the FlexToT application-specific integrated circuit (ASIC) has been designed and fabricated with an extended dynamic range and improved channel uniformity suitable for readout of different detector block designs in time of flight (TOF) positron emission tomography (PET) applications. The performance of the FlexToT v2 ASIC has been evaluated using segmented, monolithic and phoswich scintillator elements and matrices coupled to silicon photmultiplier (SiPM) arrays. The enhanced dynamic range of FlexToT v2 compared to its previous version allows the correct identification of individual crystals in scintillator matrices, both single layer and phoswich. Operation with monolithic scintillators was also demonstrated, with energy resolutions of 18% (FWHM) at 511 keV and reconstructed PET images of point sources yielding spatial resolutions on the order of 2 mm (FWHM). The results show that the FlexToT v2 ASIC is a flexible solution for the front-end readout of different designs of SiPM-based scintillator detectors in TOF-PET applications.