Cosmic ray test of a STCF DTOF detector prototype

Abstract

A time-of-flight detector based on detection of internally reflected Cherenkov light (DTOF), is proposed for the endcap particle identification at the Super Tau-Charm Facility (STCF). A prototype with a trapezoidal fused silica radiator that had a size of 533 mm/ 295 mm × 454 mm × 15 mm is constructed, which is approximately one-third of the size of the DTOF sector proposed for STCF. A field-programmable-gate-array-based dual-threshold time-over-threshold measurement circuit is employed to read signals from the microchannel-plate photomultiplier tube, which performs functions such as signal amplification, discrimination, and digitization. The DTOF prototype was tested in a cosmic ray telescope, which realizes 3D tracking of cosmic ray muons with an angular resolution of < 1 mrad, position resolution of <200μm, and reference time resolution of 24 ps. To analyze and understand the performance of the DTOF prototype, a GEANT4 simulation is employed. The time resolution of the DTOF prototype is 25 ps by using 10 or more photoelectrons in the cosmic ray test, which is in good agreement with the simulation result, proving the feasibility of this technology.