Radiation damage in silicon photomultipliers exposed to neutron radiation

摘要

We studied performances of two SiPMs before and after irradiation at the Lubljana reactor. These high density (15 μm cell pitch size) SiPMs were developed by Hamamatsu (in cooperation with the CMS SiPM group) for the CMS HCAL Upgrade Phase I project. The S10943- 4732 is a photosensor selected for the CMS HE HCAL where the SiPMs will be exposed to 2 × 10~(11) n/cm~2 (1 MeV equivalent) for the operation time of the SLHC (integrated luminosity - 5000 fb~(-1). The HD-1015CN SiPM was developed using new Hamamatsu trench technology to reduce optical cross-talk (X-talk) between SiPM cells. Both SiPMs are considered as candidates for the CMS HCAL barrel upgrade. The SiPMs were irradiated with reactor neutrons up to 1MeV equivalent fluence of 2 × 10~(12) n/cm~2 (that corresponds to the maximum integrated neutron fluence in the HCAL barrel for the duration of the SLHC operation).