Proton detection with large-acceptance scintillator detection systems in electron-scattering environments

Two highly segmented plastic-scintillator arrays have been developed for proton detection in electron scattering experiments. The detectors subtend solid angles of 225 and 550 msr and cover energy ranges of 50–225 and 25–165MeV, respectively. The charge and arrival time of each photomultiplier signal are digitized by flash ADCs and temporarily stored in a dual-port memory. The readout parameters are computer controlled, tuned, and monitored. These detectors have been employed in (e,e′p) and (e,e′pp) experiments for proton emission angles greater than 30° and for luminosities up to 1036 nucleonscm−2s−1. The singles counting rates in the scintillator elements of the first layers were about 0.5×106 particless−1 and the trigger rate 1MHz. The measured resolution in the excitation energy and timing spectra are 2.7% and 0.7ns, respectively.