用于HIAF-HFRS装置的飞行时间探测器样机性能研究

Study on the Performance of a Prototype of Time-of-flight Detectors for HIAF-HFRS Facility

本工作制作了一套由快发光塑料闪烁体耦合快光电倍增管组成的塑料闪烁体飞行时间探测器的样机,通过皮秒脉冲激光测试了探测器的时间性能,旨在为将来的HIAF-HFRS飞行时间探测器作预研。对于两种不同尺寸的塑料闪烁体探测器,通过改变激光的光斑大小、频率、光强和轰击位置等各项参数来模拟真实重离子束流的情况,并使用CAEN-DT5742数字化仪以及Mesytec-MCFD16+MTDC32电子学系统进行了系统的测试。使用聚焦激光照射在塑料闪烁体中心位置时,小尺寸(7 cm×7 cm)塑料闪烁体探测器的飞行时间(ToF)分辨最好可达8 ps;小-大(26 cm×10 cm)塑料闪烁体探测器的ToF分辨最好可达到12 ps。当改变激光各项参数后,得到对应的ToF分辨为10~16 ps和19~46 ps。测试结果表明,所得到的ToF分辨满足HFRS束线的时间分辨性能要求,为飞行时间探测器的优化奠定了基础。

In this work,a prototype of time-of-flight detectors consisting of fast plastic scintillators coupled with fast photomultiplier tubes.The time performance of the detectors was tested using a picosecond pulsed laser,aiming at providing preliminary research for developing the time-of-flight detectors deployed at the future HIAF-HFRS.For two plastic scintillator detectors with different sizes,a systematic test was conducted by changing the parameters such as spot size,frequency,light intensity and hitting position of the laser to simulate the real ion-beam conditions.The tests were performed using a CAENDT5742 digitizer and a Mesytec-MCFD16+MTDC32 electronics system.When a focused laser was directed at the center of the plastic scintillator,the best time-of-flight(ToF)resolution achieved by the two small-size(7 cm×7 cm)plastic scintillator detectors was 8 ps;for the detectors with one small size and one large size(26 cm×10 cm),the optimal ToF resolution was12 ps.When changing the parameters of the laser,the corresponding ToF resolutions were 10~16 ps and 19~46 ps,respectively.Our test results indicate that the achieved ToF resolution meets the requirements of the time resolution performance for the HFRS beamline,establishing the foundation for the optimization of the time-of-flight detectors.