Material Selection of the SPD Beam-Beam Counter Scintillation Detector Prototype

The Spin Physics Detector is an experiment at NICA designed to study the spin structure of the proton and deuteron and the other spin-related phenomena using polarized beams. Two endcap detector wheels of scintillator-based Beam-Beam Counters (BBCs) will be installed symmetrically aside from the interaction point and will serve as a tool for beam diagnostics including local polarimetry. The selection of material combinations for BBC is presented using scintillation tiles with different material combinations of the BBC prototype. The influence of the light collection was studied using matted and covered with Tyvek tiles. Different fibers (Saint-Gobain Crystals BCF91AS, BCF92S, and Kuraray Y-11), as well as different optical cements (CKTN type E, OK-72) were used. The prototypes were tested with cosmic rays and radioactive source using SensL SiPM readout.