Novel Silicon Photomultipliers for PET Applications

Silicon Photomultipliers (SiPMs) with quantum efficiency maximized for a wavelength between 420 and 470 nm have been developed at ITC-irst Trento (Italy), and are being tested for their application in the construction of a ultra high resolution small animal PET tomograph. The devices have an area of 1 mm x 1 mm and 625 microcells. The breakdown voltage is around 30 V, and the gain of the order of ${10} ^{6}$ . The intrinsic timing resolution is 70ps rms at the single photoelectron level. The first tests as readout for scintillators show an energy resolution of 21% FWHM with Na-22 employing LSO crystals. The first matrices of SiPMs have been produced and are being tested.