BESIII飞行时间探测器塑料闪烁体性能检测

Measurement of scintillators in BESIII TOF

北京谱议(BESIII)重大改造工程中飞行时间探测器所使用的各个塑料闪烁体需要严格测量和质量控制,包括机械尺寸、有效衰减长度和相对光产额。我们用宇宙线测量塑料闪烁体的衰减长度时,利用飞行时间探测器本身的时间信息重建出宇宙线的位置和方向,宇宙线在闪烁体上的光产额通过其两端光电倍增管的电荷信息来反应,这样测量的闪烁体的有效衰减长度统计量大、准确并且快速。检测结果表明,闪烁体的各项指标达到了的设计要求。

Properties of the scintillator bars are very important to the goal of 90 ps time resolution of the TOF detector on BESIII. The mechanical sizes were measured. The scintillator bars were piled up to measure the effective attenuation length and relative light output by cosmic rays. The positions hit by cosmic rays were deduced by time information acquired from the PMTs at the two ends of the scintillators. The results show that the scintillators is very good in quality for BESm TOF.