Radiation damage effects in Silicon Photo-Multipliers

In this paper we present a study of the neutrons-induced damage in Silicon Photo-Multipliers. Twenti-six devices, produced by AdvanSiD, Hamamatsu and SensL, have been irradiated at the Geel Electron LINear Accelerator (GELINA) in Belgium on a nearly white neutron beam. The total 1 MeV equivalent integrated dose was 6.2×10⁹n_eq/cm². Photodetector performances have been measured during the whole irradiation period and a gradual worsening of the detector properties, like dark current and charge spectra, has been observed. An extensive comparison of the performances of all the devices will be presented.