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 I mm x I 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 70 ps 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.