Performance test of prototype LAMPS Start Counter using proton beams at 100 MeV

LAMPS (Large Acceptance Multi-Purpose Spectrometer) is an experiment to study nuclear matter and nuclear reactions using stable and rare isotope beams at RAON (Rare isotope Accelerator for ON-line experiments). The Start Counter measures the arrival time of the beam particles in LAMPS. It is crucial for obtaining synchronized data, identifying the types of particles produced after collisions, and distinguishing the type of beam particles. For accurate timing measurement, the Start Counter consists of a plastic scintillator and readout boards with Multi-Pixel Photon Counters (MPPCs). In this study, prototypes of the Start Counter were tested using a 100 MeV proton beam at KOMAC (Korea Multi-Purpose Accelerator Complex). Details of the prototype production and time resolution measurements are presented. The time resolution of the prototype modules is measured as 113±2,118±2,77±4,98±5 ps.