Calibration study on a prototype of the Muon Telescope Detector at STAR of RHIC

A prototype of the Muon Telescope Detector (MTD) was installed at STAR (Solenoidal Tracker at RHIC) during run year 2007. While the cosmic and beam tests showed a ~ 60 - 70 ps timing resolution for MTD, the actual performance in Au + Au collisions at STAR was found ~300 ps. In run year 10 STAR implemented a new electronics system for MTD and a cosmic ray trigger to study the performance of its several subsystems. With the cosmic ray data, this study shows that the timing resolution of MTD can reach 99 ps after a full calibration.