A position-sensitive detector system with subnanosecond timing and its utilization in the measurement of pion absorption

A complex position-sensitive, time-of-flight detector was designed at the SIN to be used in the kinematically complete measurements of pion absorption in light nuclei, for the detection of both neutrons and charged particles. Design parameters and TOF properties resulting from the computer calculations and suitable test measurements are given for the system consisting of 200x10x5 cm3 NE 102A scintillator bars, XP 2230 photomultipliers and discriminator. Position dependence of the timing parameters of the 2 m long NE 102A bar viewed from the ends by photomultipliers has been clearly revealed in our model and experimentally verified. (orig.)