Neutron irradiation test of Hamamatsu, SensL and AdvanSiD UV-extended SiPMs

In this paper, we report the measurement of the neutron radiation hardness of custom Silicon Photomultipliers arrays (SiPMs) manufactured by three companies: Hamamatsu (Japan), AdvanSiD (Italy) and SensL (Ireland). These custom SiPMs consist of a 2 x 3 array of 6 x 6 mm^2 monolithic cells with pixel sizes of respectively 50 um (Hamamatsu and SensL) and 30 um (AdvanSid). A sample from each vendor has been exposed to neutrons generated by the Elbe Positron Source facility (Dresden), up to a total fluence of ~ 8.5 x 10^11 n_(1 MeV)/cm^2. Test results show that the dark current increases almost linearly with the neutron fluence. The room temperature annealing was quantified by measuring the dark current two months after the irradiation test. The dependence of the dark current on the device temperature and on the applied bias have been also evaluated.