基于SiPM读出的塑料闪烁体探测器时间性能研究

Time Performance Study of Plastic Scintillator Detector with SiPM Readouts

研究了基于硅光电倍增管(SiPM)双端读出的面积为10cm×10 cm的薄塑料闪烁体探测器的时间性能。^(239)Pu放射源测试结果显示:(1)在多支SiPM串连读出方式下,随着SiPM数量的增加,探测器时间分辨逐渐变好;(2)在固定12支SiPM数量不变的情况下,并联支路越多,探测器时间分辨越差;(3)采用快时间塑料闪烁体并增加其厚度,可有效提高探测器时间分辨;(4)采用比束斑尺寸更大的塑料闪烁体,可有效提高探测器时间分辨的位置均匀性;(5)对于1 mm厚的EJ232塑料闪烁体探测器,在单端12支SiPM串行连接的情况下,可获得好于131ps的时间分辨。这一研究对RIBLL2起始时间探测器的升级改造具有重要的指导意义。

In this paper the time performance of a plastic scintillator detector with an area of 10 cm×10 cm and read out by multiple silicon photomultipliers(SiPMs) at both ends was studied.The results tested with a ^(239)Pu source are shown as:(1) the time resolutions became better gradually with the increase of the quantities of SiPMs connected in series;(2) when the number of 12 SiPMs was fixed,the time resolutions got worse as the number of parallel branches were increased;(3) the detector time resolutions can be effectively improved by using a fast-time plastic scintillator and adding its thickness;(4) to improve the positional uniformity of the time resolution,the scintillator with larger dimensions than beam spots should be used;(5) a resolution less than 131 ps was achieved with a 0.1 cm thickness EJ232 scintillator detector read out on each side by 12 SiPMs conncted in series.This study has importance significance for the upgrading of the start detector at RIBLL2.