Radiation hardness of Silicon Photomultipliers for CBM@FAIR, NA61@CERN and BM@N experiments

Abstract

Results of radiation hardness study of Silicon Photomultipliers (SiPMs) to be used at forward hadron calorimeters, including designed Projectile Spectator Detector (PSD) of CBM, PSD of NA61 beyond 2020 upgrade and Zero Degree Calorimeter (ZDC) at BM@N are presented. High intensity beams at future heavy-ion accelerator facilities up to 106∕107 interactions/second will lead to high neutron fluence around calorimeters up to 3×1012 neq/cm2 accumulated during a year of the experiment operation. SiPMs produced by Ketek, Zecotek, Hamamatsu and Sensl manufacturers were irradiated at cyclotron of NPI Rez in a wide range of neutron fluences from 4×1010 up to 6×1012 n/cm2. Change of SiPM’s main parameters after irradiation including dark current, breakdown voltage, noise and signal response to LED was studied in the lab. Furthermore, several packs of irradiated SiPMs were installed at the currently operating NA61 PSD to study the cumulative radiation effect on the calorimeter performance. Beam scan with 20–80 GeV/c protons was performed to determine the dependency of detector energy resolution on beam energy before and after irradiation.