Keywords: 
• plastic scintillator /
• time-of-flight detector /
• ToF resolution /
• pico-second pulsed laser /
• HIAF-HFRS

Abstract: 

In this work, we presented the test results for a prototype of plastic scintillation detectors for time-of-flight measurement, aiming to provide preliminary research for the future development of time-of-flight detectors for HIAFHFRS facility. Each timing detectors was composed of a fast scintillating plastic and four fast photomultiplier tubes coupled to its four sides. The time performance of the detectors was tested using pico-second pulsed laser, For two plastic scintillation detectors with different sizes, a pico-second pulsed laser was used to simulating the actual ionbeam situation by changing laser’s parameters including spot size, repetition rate, light intensity and hitting position. The data was processed utilizing CAEN-DT5742 digitizer and Mesytec-MCFD16+MTDC32 electronics. When the focused laser hit at the center of the plastic scintillators, the time-of-flight (ToF) resolution of two small-sized (7 cm×7cm)plastic scintillation detectors could reach 8 ps, whereas the ToF resolution of the small and large (26 cm×10 cm) detectors could achieve 12 ps. After varying the parameters of the laser, the corresponding ToF resolutions were found to be in the range of 10–16 ps and 19–46 ps, respectively. The ToF resolutions from the test meets the timing-resolution requirement of the HFRS beamline, thereby establishing a solid foundation for further optimizing the time-of-flight detectors.